LDL oxidation
1. Clin Chem. 2000 Nov;46(11):1818-29.
Influence of increased fruit and vegetable intake on plasma and lipoprotein
carotenoids and LDL oxidation in smokers and nonsmokers.
Chopra M, O'Neill ME, Keogh N, Wortley G, Southon S, Thurnham DI.
Northern Ireland Centre for Diet and Health, School of Biomedical Sciences,
University of Ulster, Coleraine, County Londonderry, Northern Ireland
BT52 1SA,
United Kingdom. M.Chopra@ulst.ac.uk
BACKGROUND: Epidemiological studies suggest a cardioprotective role for
carotenoid-rich foods. Smokers have a high risk of cardiovascular disease
and
low dietary intake and plasma concentrations of carotenoids. The aim of
this
study was to determine the carotenoid response of smokers and nonsmokers
to
increased intake of 300-400 g of vegetables and its effect on LDL oxidation.
METHODS: After a depletion period of 8 days, 34 healthy females (18 nonsmokers,
16 smokers) were supplemented with beta-carotene- and lutein-rich (green)
and
lycopene-rich (red) vegetable foods, each for 7 days. RESULTS: Baseline
concentrations (mean +/- SD) of plasma beta-carotene (0.203+/-0.28 micromol/L
vs. 0.412+/-0.34 micromol/L; P <0.005) and lutein (0.180 +/-0.10 vs.
0.242+/-0.11 micromol/L; P<0.05) but not lycopene (0.296+/-0.10 vs.
0.319+/-0.33
micromol/L) were significantly lower in smokers compared with nonsmokers.
After
supplementation, the change (supplementation minus depletion) in plasma
beta-carotene (0.152+/- 0.43 vs. 0.363+/-0.29 micromol/L in smokers vs.
nonsmokers; P = 0.002) and LDL lutein (0.015+/-0.03 vs. 0.029+/-0.03
micromol/mmol cholesterol; P = 0.01) was significantly lower in smokers
than
nonsmokers. Green-vegetable supplementation had no effect on the resistance
of
LDL to oxidation (lag-phase) in either group. After red-vegetable
supplementation, plasma and LDL lycopene concentrations were increased
in both
groups, but only nonsmokers showed a significant increase in the lag-phase
(44.9+/-9.5 min at baseline, 41.4+/-6.5 min after depletion, and 49.0+/-8.9
min
after supplementation; P<0.01) compared with depletion. CONCLUSIONS:
In this
short-term intervention study, a dietary intake of >40 mg/day of lycopene
by a
group of nonsmoking individuals significantly reduced the susceptibility
of LDL
to oxidation, whereas an equivalent increase in lycopene by a group of
smokers
showed no such effect.
2. Antioxid Redox Signal. 2000 Fall;2(3):491-506.
Lycopene synergistically inhibits LDL oxidation in combination with vitamin
E,
glabridin, rosmarinic acid, carnosic acid, or garlic.
Fuhrman B, Volkova N, Rosenblat M, Aviram M.
Lipid Research Laboratory, Technion Faculty of Medicine, The Rappaport
Family
Institute for Research in the Medical Sciences and Rambam Medical Center,
Haifa,
Israel.
Several lines of evidence suggest that oxidatively modified low-density
lipoprotein (LDL) is atherogenic, and that atherosclerosis can be attenuated
by
natural antioxidants, which inhibit LDL oxidation. This study was conducted
to
determine the effect of tomato lycopene alone, or in combination with
other
natural antioxidants, on LDL oxidation. LDL (100 microg of protein/ml)
was
incubated with increasing concentrations of lycopene or of tomato oleoresin
(lipid extract of tomatoes containing 6% lycopene, 0.1% beta-carotene,
1%
vitamin E, and polyphenols), after which it was oxidized by the addition
of 5
micromol/liter of CuSO4. Tomato oleoresin exhibited superior capacity
to inhibit
LDL oxidation in comparison to pure lycopene, by up to five-fold [97%
vs. 22%
inhibition of thiobarbituric acid reactive substances (TBARS) formation,
and 93%
vs. 27% inhibition of lipid peroxides formation, respectively]. Because
tomato
oleoresin also contains, in addition to lycopene, vitamin E, flavonoids,
and
phenolics, a possible cooperative interaction between lycopene and such
natural
antioxidants was studied. A combination of lycopene (5 micromol/liter)
with
vitamin E (alpha-tocopherol) in the concentration range of 1-10 micromol/liter
resulted in an inhibition of copper ion-induced LDL oxidation that was
significantly greater than the expected additive individual inhibitions.
The
synergistic antioxidative effect of lycopene with vitamin E was not shared
by
gamma-to-cotrienol. The polyphenols glabridin (derived from licorice),
rosmarinic acid or carnosic acid (derived from rosemary), as well as garlic
(which contains a mixture of natural antioxidants) inhibited LDL oxidation
in a
dose-dependent manner. When lycopene (5 micromol/liter) was added to LDL
in
combination with glabridin, rosmarinic acid, carnosic acid, or garlic,
synergistic antioxidative effects were obtained against LDL oxidation
induced
either by copper ions or by the radical generator AAPH. Similar interactive
effects seen with lycopene were also observed with beta-carotene, but,
however,
to a lesser extent of synergism. Because natural antioxidants exist in
nature in
combination, the in vivo relevance of lycopene in combination with other
natural
antioxidants was studied. Four healthy subjects were administered a fatty
meal
containing 30 mg of lycopene in the form of tomato oleoresin. The lycopene
concentration in postprandial plasma was elevated by 70% in comparison
to plasma
obtained before meal consumption. Postprandial LDL isolated 5 hr after
meal
consumption exhibited a significant (p < 0.01) reduced susceptibility
to
oxidation by 21%. We conclude that lycopene acts synergistically, as an
effective antioxidant against LDL oxidation, with several natural antioxidants
such as vitamin E, the flavonoid glabridin, the phenolics rosmarinic acid
and
carnosic acid, and garlic. These observations suggest a superior antiatherogenic
characteristic to a combination of different natural antioxidants over
that of
an individual one.
3. Diabetes Care. 2000 Jun;23(6):733-8.
Effect of supplementation with tomato juice, vitamin E, and vitamin C
on LDL
oxidation and products of inflammatory activity in type 2 diabetes.
Upritchard JE, Sutherland WH, Mann JI.
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
OBJECTIVE: To compare the effects of short-term dietary supplementation
with
tomato juice, vitamin E, and vitamin C on susceptibility of LDL to oxidation
and
circulating levels of C-reactive protein (C-RP) and cell adhesion molecules
in
patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: There were
57
patients with well-controlled type 2 diabetes aged <75 years treated
with
placebo for 4 weeks and then randomized to receive tomato juice (500 ml/day),
vitamin E (800 U/day), vitamin C (500 mg/day), or continued placebo treatment
for 4 weeks. Susceptibility of LDL to oxidation (lag time) and plasma
concentrations of lycopene, vitamin E, vitamin C, C-RP, vascular cell
adhesion
molecule 1, and intercellular adhesion molecule 1 were measured at the
beginning
of the study, after the placebo phase, and at the end of the study. RESULTS:
Plasma lycopene levels increased nearly 3-fold (P = 0.001), and the lag
time in
isolated LDL oxidation by copper ions increased by 42% (P = 0.001) in
patients
during supplementation with tomato juice. The magnitude of this increase
in lag
time was comparable with the corresponding increase during supplementation
with
vitamin E (54%). Plasma C-RP levels decreased significantly (-49%, P =
0.004) in
patients who received vitamin E. Circulating levels of cell adhesion molecules
and plasma glucose did not change significantly during the study. CONCLUSIONS:
This study indicates that consumption of commercial tomato juice increases
plasma lycopene levels and the intrinsic resistance of LDL to oxidation
almost
as effectively as supplementation with a high dose of vitamin E, which
also
decreases plasma levels of C-RP, a risk factor for myocardial infarction,
in
patients with diabetes. These findings may be relevant to strategies aimed
at
reducing risk of myocardial infarction in patients with diabetes.
Lipids. 1998 Oct;33(10):981-4.
Tomato lycopene and low density lipoprotein oxidation: a human dietary
intervention study.
4. Agarwal S, Rao AV.
Department of Nutritional Sciences, Faculty of Medicine, University of
Toronto,
Ontario, Canada.
Increase in low density lipoprotein (LDL) oxidation is hypothesized to
be
causally associated with increasing risk of atherosclerosis and coronary
heart
disease. In recent epidemiological studies, tissue and serum levels of
lycopene,
a carotenoid available from tomatoes, have been found to be inversely
related to
risk of coronary heart disease. A study was undertaken to investigate
the effect
of dietary supplementation of lycopene on LDL oxidation in 19 healthy
human
subjects. Dietary lycopene was provided using tomato juice, spaghetti
sauce, and
tomato oleoresin for a period of 1 wk each. Blood samples were collected
at the
end of each treatment. Serum lycopene was extracted and measured by
high-performance liquid chromatography using an absorbance detector. Serum
LDL
was isolated by precipitation with buffered heparin, and thiobarbituric
acid-reactive substances (TBARS) and conjugated dienes (CD) were measured
to
estimate LDL oxidation. Both methods, to measure LDL oxidation LDL-TBARS
and
LDL-CD, were in good agreement with each other. Dietary supplementation
of
lycopene significantly increased serum lycopene levels by at least twofold.
Although there was no change in serum cholesterol levels (total, LDL,
or
high-density lipoprotein), serum lipid peroxidation and LDL oxidation
were
significantly decreased. These results may have relevance for decreasing
the
risk for coronary heart disease.
Lung Cancer/function
5. Am J Clin Nutr. 2000 Oct;72(4):990-7.
Comment in:
Am J Clin Nutr. 2000 Oct;72(4):901-2.
Am J Clin Nutr. 2001 Aug;74(2):273-4.
Intake of specific carotenoids and risk of lung cancer in 2 prospective
US
cohorts.
Michaud DS, Feskanich D, Rimm EB, Colditz GA, Speizer FE, Willett WC,
Giovannucci E.
Departments of Nutrition and Epidemiology, Harvard School of Public Health,
Boston, MA 02115, USA.
BACKGROUND: Carotenoids may reduce lung carcinogenesis because of their
antioxidant properties; however, few studies have examined the relation
between
intakes of individual carotenoids and lung cancer risk. OBJECTIVE: The
aim of
this study was to examine the relation between lung cancer risk and intakes
of
alpha-carotene, beta-carotene, lutein, lycopene, and beta-cryptoxanthin
in 2
large cohorts. DESIGN: During a 10-y follow-up period, 275 new cases of
lung
cancer were diagnosed in 46924 men; during a 12-y follow-up period, 519
new
cases were diagnosed in 77283 women. Carotenoid intakes were derived from
the
reported consumption of fruit and vegetables on food-frequency questionnaires
administered at baseline and during follow-up. The data were analyzed
separately
for each cohort and the results were pooled to compute overall relative
risks
(RRs). RESULTS: In the pooled analyses, alpha-carotene and lycopene intakes
were
significantly associated with a lower risk of lung cancer; the association
with
beta-carotene, lutein, and beta-cryptoxanthin intakes were inverse but
not
significant. Lung cancer risk was significantly lower in subjects who
consumed a
diet high in a variety of carotenoids (RR: 0.68; 95% CI: 0.49, 0.94 for
highest
compared with lowest total carotenoid score category). Inverse associations
were
strongest after a 4-8-y lag between dietary assessment and date of diagnosis.
In
subjects who never smoked, a 63% lower incidence of lung cancer was observed
for
the top compared with the bottom quintile of alpha-carotene intake (RR:
0.37;
95% CI: 0.18, 0.77). CONCLUSION: Data from 2 cohort studies suggest that
several
carotenoids may reduce the risk of lung cancer.
6. Am J Respir Crit Care Med. 2000 Mar;161(3 Pt 1):790-5.
Serum carotenoids, alpha-tocopherol, and lung function among Dutch elderly.
Grievink L, de Waart FG, Schouten EG, Kok FJ.
Division of Human Nutrition and Epidemiology, Wageningen University and
Research
Center, Wageningen, The Netherlands.
Antioxidant vitamins (provitamins) may protect against loss of lung function
over time. We studied the association between serum carotenoids (alpha-carotene,
beta-carotene, lycopene, beta-cryptoxanthin, zeaxanthin, and lutein),
alpha-tocopherol, and lung function among noninstitutionalized Dutch elderly
age
65 to 85 yr (n = 528). Multiple linear regression analysis was performed
with
FEV(1) or FVC as dependent variables and serum levels of antioxidants
in
quintiles as independent variables. We adjusted for age, gender, height,
and
pack-years of smoking. Subjects in the fifth quintile of serum beta-carotene
had
a 195 ml (95% confidence interval [95% CI]: 40 to 351 ml) higher and those
in
the fifth quintile of alpha-carotene had a 257 ml (95% CI: 99 to 414 ml)
higher
FEV(1) compared with subjects in the first quintile of these carotenoids.
Significant (p < 0.05) positive trends were observed between alpha-carotene,
beta-carotene, lycopene, and FEV(1) and between alpha-carotene, beta-carotene,
and FVC. Subjects in the highest quintile of the other carotenoids or
alpha-tocopherol did not have significantly higher FEV(1) or FVC compared
with
subjects in the first quintile of these antioxidants. In conclusion, this
study
shows that from the six major serum carotenoids and alpha-tocopherol studied,
particularly alpha-carotene, beta-carotene, and lycopene were positively
associated with lung function in the elderly and may be considered as
candidates
for further investigations.
Gastric ulcer
7. J Clin Gastroenterol. 2000 Jun;30(4):381-5.
Comment in:
J Clin Gastroenterol. 2000 Jun;30(4):341-2.
J Clin Gastroenterol. 2001 Jan;32(1):91-2.
Micronutrient antioxidants in gastric mucosa and serum in patients with
gastritis
and gastric ulcer: does Helicobacter pylori infection affect the mucosal
levels?
Nair S, Norkus EP, Hertan H, Pitchumoni CS.
Division of Gastroenterology, Johns Hopkins University School of Medicine
Baltimore, Maryland, USA.
Free radicals (FRs) play an important role in the pathogenesis of gastroduodenal
mucosal inflammation, peptic ulcer disease, and probably even gastric
cancer.
Various micronutrients protect the gastric mucosa by scavenging FRs. Only
limited data is available regarding the concentration of micronutrients
in the
gastric mucosa in patients with gastritis and peptic ulcer disease. Our
aim was
to analyze micronutrient antioxidant concentrations in the antral mucosa
in
patients with gastritis and gastric ulcer and to determine the influence
of
Helicobacter pylori infection on gastric mucosal antioxidants in patients
with
gastritis and gastric ulcer. Patients who underwent upper endoscopy for
evaluation of dyspepsia were included in the study. Ascorbic acid,
alpha-tocopherol, alpha-carotene, beta-carotene, total carotenoids, lutein,
cryptoxanthin, and lycopene levels were measured in the sera and antral
mucosal
biopsies in these patients. The diagnosis of H. pylori was confirmed by
histology, urease test (CLO) and serology. Patients with negative endoscopic
findings and normal histology and no H. pylori infection served as controls.
In
patients with gastritis, alpha-tocopherol levels were reduced in serum
and
mucosa irrespective of H. pylori status, whereas carotenoids and ascorbic
acid
levels were similar to controls. However, in patients with gastric ulcer,
serum
and mucosal levels of all micronutrient antioxidants were markedly decreased
compared with both controls and patients with gastritis. The degree of
depletion
of antioxidants was similar in patients with either H. pylori-induced
or
nonsteroidal antiinflammatory drug (NSAID)-induced ulcers. Patients with
gastric
ulcer have very low gastric antioxidant concentrations compared to patients
with
gastritis and normal mucosa. This depletion in antioxidants seems to be
a
nonspecific response and was not related to H. pylori infection.
Homocysteine
8. J Nutr. 2000 Jun;130(6):1578-83.
Fruits and vegetables increase plasma carotenoids and vitamins and decrease
homocysteine in humans.
Broekmans WM, Klopping-Ketelaars IA, Schuurman CR, Verhagen H, van den
Berg H,
Kok FJ, van Poppel G.
TNO Nutrition and Food Research, 3700 AJ Zeist, The Netherlands.
Observational epidemiologic studies have shown that a high consumption
of fruits
and vegetables is associated with a decreased risk of chronic diseases.
Little
is known about the bioavailability of constituents from vegetables and
fruits
and the effect of these constituents on markers for disease risk. Currently,
the
recommendation is to increase intake of a mix of fruits and vegetables
("five a
day"). We investigated the effect of this recommendation on plasma
carotenoids,
vitamins and homocysteine concentrations in a 4-wk dietary controlled,
parallel
intervention study. Male and female volunteers (n = 47) were allocated
randomly
to either a daily 500-g fruit and vegetable ("high") diet or
a 100-g fruit and
vegetable ("low") diet. Analyzed total carotenoid, vitamin C
and folate
concentrations of the daily high diet were 13.3 mg, 173 mg and 228.1 microg,
respectively. The daily low diet contained 2.9 mg carotenoids, 65 mg vitamin
C
and 131.1 microg folate. Differences in final plasma levels between the
high and
low group were as follows: lutein, 46% [95% confidence interval (CI) 28-64];
beta-cryptoxanthin, 128% (98-159); lycopene, 22% (8-37); alpha-carotene,
121%
(94-149); beta-carotene, 45% (28-62); and vitamin C, 64% (51-77) (P <
0.05). The
high group had an 11% (-18 to -4) lower final plasma homocysteine and
a 15%
(0.8-30) higher plasma folate concentration compared with the low group
(P <
0.05). This is the first trial to show that a mix of fruits and vegetables,
with
a moderate folate content, decreases plasma homocysteine concentrations
in
humans.
Diabetes
9. Diabetes Metab Res Rev. 2000 Jan-Feb;16(1):15-9.
Plasma levels of lipophilic antioxidants in very old patients with type
2
diabetes.
Polidori MC, Mecocci P, Stahl W, Parente B, Cecchetti R, Cherubini A,
Cao P,
Sies H, Senin U.
Institute of Gerontology and Geriatrics, Perugia University Hospital,
Perugia,
Italy. polidori@uni-duesseldorf.de
BACKGROUND: Experimental research indicates that oxidative stress is
implicated
in aging and in the pathogenesis of diabetes and its complications. This
evidence is limited in elderly patients with non-insulin dependent diabetes,
in
which age- and disease-related production of reactive oxygen species might
exert
synergistic damaging effects on tissues and organs. METHODS: Plasma levels
of
lipid-soluble compounds with antioxidant properties including vitamin
A, vitamin
E and carotenoids (lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-
and
beta-carotene) were measured by HPLC in 72 elderly patients with non-insulin
dependent diabetes (75.7+/-0.8 years, 40 F, 32 M) and in 75 age-matched
controls
(77.2+/-1.2 years, 48 F, 27 M). RESULTS: All compounds measured were
significantly lower in plasma from diabetic patients as compared to controls
(p<0.0001). Plasma levels of vitamins A and E and of carotenoids did
not
significantly correlate with dietary intake and lipid profile in both
groups. In
patients, significant inverse correlations were found between age and
levels of
vitamin E, beta-cryptoxanthin, lycopene and beta-carotene. CONCLUSIONS:
We
conclude that patients of very old age with Type 2 diabetes show a poor
plasma
status of vitamins A and E and carotenoids, which negatively correlates
with
age. Further studies are needed to explore the possible therapeutic role
of
lipid-soluble vitamin supplements in elderly diabetic subjects. Copyright
2000
John Wiley & Sons, Ltd.
10. Am J Clin Nutr. 2001 Jan;73(1):68-74.
Differences in body fat distribution and antioxidant status in Korean
men with
cardiovascular disease with or without diabetes.
Jang Y, Lee JH, Cho EY, Chung NS, Topham D, Balderston B.
Division of Cardiology, Yonsei Cardiovascular Center, Yonsei University,
Seoul,
Korea.
BACKGROUND: Abnormal body fat distribution and reduced antioxidant status
have
been shown to be effective markers of risk of cardiovascular disease (CVD).
OBJECTIVE: The objective of this study was to determine the differences
in body
fat distribution and antioxidant status in healthy men (control subjects)
and in
men with CVD with or without diabetes. DESIGN: An oral-glucose-tolerance
test
was performed and CVD patients were subdivided into groups according to
the
presence or absence of diabetes. Adipose tissue areas were calculated
from
computed tomography scans made at the L1 and L4 vertebrae. Fasting serum
concentrations of lipids, testosterone, insulin-like growth factor I,
antioxidants, and plasma homocysteine were determined. RESULTS: There
were no
significant differences in mean age, body mass index (in kg/m(2)), or
blood
pressure between the groups. The visceral fat area at the L1 vertebra
was
nonsignificantly greater in CVD patients without diabetes than in control
subjects, whereas it was significantly greater in CVD patients with diabetes
than in control subjects at both the L1 and L4 vertebrae. Both groups
of CVD
patients had higher plasma concentrations of homocysteine and lower serum
insulin-like growth factor I concentrations and superoxide dismutase activities
than did control subjects. Serum ss-carotene and lycopene concentrations
were
lowest in the CVD patients with diabetes. CONCLUSION: The concurrent presence
of
CVD and diabetes is associated with a greater negative effect on the risk
factors typically associated with significant declines in health status.
Heart
11. J Nutr. 2003 Jul;133(7):2336-41.
Dietary lycopene, tomato-based food products and cardiovascular disease
in
women.
Sesso HD, Liu S, Gaziano JM, Buring JE.
Division of Preventive Medicine, Department of Medicine, Brigham and
Women's
Hospital, Boston, MA, USA. hsesso@hsph.harvard.edu
In addition to the inverse association of dietary lycopene with various
cancers,
studies suggest a role for lycopene in cardiovascular disease (CVD) prevention.
We determined whether the intake of lycopene or tomato-based foods is
associated
with the risk of CVD in a prospective cohort of 39,876 middle-aged and
older
women initially free of CVD and cancer. Participants completed a food-frequency
questionnaire and provided self-reports of coronary risk factors. Dietary
lycopene levels were divided into quintiles, and primary lycopene food
sources
(total tomato-based products, including tomatoes, tomato juice, tomato
sauce and
pizza) were categorized. During 7.2 y of follow-up, 719 CVD cases (including
myocardial infarction, stroke, revascularization and CVD death) occurred.
Compared with women in the 1st quintile of lycopene, those in increasing
quintiles had multivariate relative risks (RR) of CVD of 1.11, 1.14, 1.15
and
0.90 (P for trend = 0.34). For the consumption of tomato-based products,
women
consuming 1.5 to <4, 4 to <7, 7 to <10 and >or=10 servings/wk
had RR (95% CI) of
CVD of 1.02 (0.82-1.26), 1.04 (0.82-1.31), 0.68 (0.49-0.96) and 0.71 (0.42-1.17)
(P for trend = 0.029) compared with women consuming <1.5 servings/wk.
Among
lycopene food sources, those in the highest levels of tomato sauce (>or=2
servings/wk) and pizza intake (>or=2 servings/wk), with multivariate
RR of 0.76
(0.55-1.05) and 0.66 (0.37-1.18), respectively, had potential reductions
in CVD
risk. Dietary lycopene was not strongly associated with the risk of CVD.
However, the possible inverse associations noted for higher levels of
tomato-based products, particularly tomato sauce and pizza, with CVD suggest
that dietary lycopene or other phytochemicals consumed as oil-based tomato
products confer cardiovascular benefits.
12. Am J Clin Nutr. 2003 Jan;77(1):133-8.
Serum lycopene concentrations and carotid atherosclerosis: the Kuopio
Ischaemic
Heart Disease Risk Factor Study.
Rissanen TH, Voutilainen S, Nyyssonen K, Salonen R, Kaplan GA, Salonen
JT.
Research Institute of Public Health, Department of Public Health and
General
Practice, University of Kuopio, Kuopio, Finland.
BACKGROUND: Interest in lycopene is growing rapidly following the recent
publication of epidemiologic studies in which high circulating lycopene
concentrations were associated with reductions in cardiovascular disease.
Lycopene is one of the major carotenoids in the Western diet and is probably
one
of the protective factors in a vegetable-rich diet. OBJECTIVE: We studied
the
hypothesis that the intima-media thickness of the common carotid artery
(CCA-IMT) would be greater in men with low serum lycopene concentrations.
DESIGN: We investigated the relation between serum lycopene concentration
and
CCA-IMT in 1028 middle-aged men (aged 46-64 y) in eastern Finland who
were
participants in the Kuopio Ischaemic Heart Disease Risk Factor study and
who
were examined in 1991-1993. The subjects were classified into quarters
according
to serum lycopene concentration. RESULTS: In a covariance analysis with
adjustment for covariates, the men in the lowest quarter of serum lycopene
concentration had a significantly higher mean CCA-IMT and maximal CCA-IMT
(P =
0.005 and P = 0.001 for the difference, respectively) than did the other
men.
The mean and maximal CCA-IMT increased linearly across the quarters of
serum
lycopene concentration. CONCLUSIONS: A low serum lycopene concentration
is
associated with a higher CCA-IMT in middle-aged men from eastern Finland.
This
finding suggests that the serum lycopene concentration may play a role
in the
early stages of atherosclerosis. Increased thickness of the intima-media
has
been shown to predict coronary events; thus, lycopene intakes and serum
concentrations may have clinical and public health relevance.
13. Am Heart J. 2002 Mar;143(3):467-74.
Inverse association between carotid intima-media thickness and the antioxidant
lycopene in atherosclerosis.
Gianetti J, Pedrinelli R, Petrucci R, Lazzerini G, De Caterina M, Bellomo
G, De
Caterina R.
C. N. R. Institute of Clinical Physiology, University of Pisa, Pisa,
Italy.
BACKGROUND: Antioxidants may prevent atherosclerosis by interfering with
endothelial activation, which involves the expression of endothelial adhesion
molecules. The aim of this study was to explore the relationship between
plasma
levels of some lipid-soluble antioxidants (gamma-tocopherol, alpha-tocopherol,
lycopene, beta-carotene, and ubiquinone), carotid maximum intima-media
thickness
(IMTmax), an index of atherosclerotic extension/severity, and soluble
adhesion
molecules (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion
molecule-1 [ICAM-1], and E-selectin), which are taken as a reflection
of
vascular cell expression of adhesion molecules. METHODS: We studied 11
healthy
control subjects, 11 patients with uncomplicated hypertension (UH), and
11
patients with essential hypertension plus peripheral vascular disease
(PVD) who
were matched for age, sex, smoking habit, and body mass index. RESULTS:
Patients
with PVD had elevated IMTmax (2.7 [1.1-3.1] mm, median [range]) compared
with
both patients with UH(1.2 [0.8-2.4] mm) and control subjects (1.0 [0.6-2]
mm).
In patients with PVD, soluble (s)VCAM-1 and sICAM-1 were also significantly
higher than in the 2 other categories. Plasma levels of lycopene had a
trend
toward lower values in patients with PVD compared with other groups (P
=.13). A
statistically significant correlation was found between lycopene and IMTmax
(r =
0.42, P =.014) at univariate analysis, which persisted at multivariate
analysis
(P <.05) and was independent of low-density lipoprotein cholesterol,
creatinine
clearance, and plasma insulin. Plasma lycopene did not significantly correlate
with any of the soluble adhesion molecules tested. CONCLUSIONS: We conclude
that
the inverse relationship of plasma lycopene with IMTmax is compatible
with a
protective role of this natural dietary antioxidant in atherosclerosis,
although
the mechanism of protection does not apparently involve a decrease in
endothelial activation measured through soluble adhesion molecules.
14. Free Radic Biol Med. 2002 Jan 15;32(2):148-52.
Plasma lipophilic antioxidants and malondialdehyde in congestive heart
failure
patients: relationship to disease severity.
Polidori MC, Savino K, Alunni G, Freddio M, Senin U, Sies H, Stahl W,
Mecocci P.
Institute of Physiological Chemistry I, Heinrich-Heine University, Dusseldorf,
Germany. polidori@uni-duesseldorf.de
Plasma levels of malondialdehyde (MDA), vitamin A, and of antioxidant
micronutrients including vitamin E, lutein, zeaxanthin, beta-cryptoxanthin,
lycopene, and alpha- and beta-carotene were measured in 30 patients with
class
II and III congestive heart failure (CHF) according to the New York Heart
Association (NYHA) classification and in 55 controls. Ejection fraction
was
evaluated by echocardiography in all patients as a measure of the emptying
capacity of the heart. Plasma levels of all measured compounds were
significantly lower and MDA significantly higher in patients compared
to
controls (p <.001). Class II NYHA patients showed significantly lower
MDA levels
and significantly higher levels of vitamin A, vitamin E, lutein, and lycopene
than class III patients. Ejection fraction was inversely correlated with
MDA
levels and directly correlated with vitamin A, vitamin E, lutein, and
lycopene
levels in patients. The present study supports the concept that an increased
consumption of vitamin-rich fruits and vegetables might help in achieving
cardiovascular health.
15. J Am Coll Cardiol. 2001 Dec;38(7):1788-94.
Comment in:
J Am Coll Cardiol. 2001 Dec;38(7):1795-8.
Antioxidant vitamins and the risk of carotid atherosclerosis. The Perth
Carotid
Ultrasound Disease Assessment study (CUDAS).
McQuillan BM, Hung J, Beilby JP, Nidorf M, Thompson PL.
Gairdner Campus of the Heart Research Institute of Western Australia,
Western,
Nedlands, Perth, Australia.
OBJECTIVES: This study examined whether dietary intake or plasma levels
of
antioxidant vitamins were independently associated with common carotid
artery
intima-media (wall) thickness (IMT) or focal plaque, or both, in a large,
randomly selected community population. BACKGROUND: Oxidation of low-density
lipoprotein (LDL) cholesterol is thought to be important in early atherogenesis.
Antioxidant micronutrients may therefore protect against lipid peroxidation
and
atherosclerotic vascular disease. METHODS: We studied 1,111 subjects (558
men
and 553 women; age 52 +/- 13 years [mean +/- SD], range 27 to 77). We
measured
dietary vitamin intake and fasting plasma levels of vitamins A, C and
E,
lycopene and alpha- and beta-carotene and performed bilateral carotid
artery
B-mode ultrasound imaging. RESULTS; After adjustment for age and conventional
risk factors, there was a progressive decrease in mean IMT, with increasing
quartiles of dietary vitamin E intake in men (p = 0.02) and a nonsignificant
trend in women (p = 0.10). Dietary vitamin E levels accounted for 1% of
the
variance in measured IMT in men. For plasma antioxidant vitamins, there
was an
inverse association between carotid artery mean IMT and plasma lycopene
in women
(p = 0.047), but not in men. None of the other dietary or plasma antioxidant
vitamins, nor antioxidant vitamin supplements, were associated with carotid
artery IMT or focal carotid artery plaque. CONCLUSIONS: This study provides
limited support for the hypothesis that increased dietary intake of vitamin
E
and increased plasma lycopene may decrease the risk of atherosclerosis.
No
benefit was demonstrated for supplemental antioxidant vitamin use.
16. J Nutr Sci Vitaminol (Tokyo). 2001 Jun;47(3):213-21.
Effects of tomato juice consumption on plasma and lipoprotein carotenoid
concentrations and the susceptibility of low density lipoprotein to oxidative
modification.
Maruyama C, Imamura K, Oshima S, Suzukawa M, Egami S, Tonomoto M, Baba
N, Harada
M, Ayaori M, Inakuma T, Ishikawa T.
Department of Food and Nutrition, Japan Women's University, Tokyo.
Effects of tomato juice supplementation on the carotenoid concentration
in
lipoprotein fractions and the oxidative susceptibility of LDL were investigated
in 31 healthy Japanese female students. These subjects were randomized
to one of
three treatment groups; Control, Low and High. The Control, Low and High
groups
consumed 480 g of a control drink, 160 g of tomato juice plus 320 g of
the
control drink, and 480 g of tomato juice, providing 0, 15 and 45 mg of
lycopene,
respectively, for one menstrual cycle. The ingestion of tomato juice,
rich in
lycopene but having little beta-carotene, increased both lycopene and
beta-carotene. Sixty-nine percent of lycopene in plasma was distributed
in the
LDL fraction and 24% in the HDL fraction. In the Low group, the lycopene
concentration increased 160% each in the VLDL+IDL, LDL and HDL fractions
(p<0.01). In the High group, the lycopene concentration increased 270%
each in
the VLDL+IDL and LDL fractions, and 330% in the HDL fraction (p<0.01).
Beta-carotene also increased 120% and 180% in LDL fractions of the Low
and the
High groups, respectively. Despite these carotenoid increases in LDL,
the lag
time before oxidation was not prolonged as compared with that of the Control
group. The propagation rate decreased significantly after consumption
in the
High group. Multiple regression analysis showed a positive correlation
between
lag time changes and changes in the alpha-tocopherol concentration per
triglyceride in LDL, and a negative correlation between propagation rate
changes
and changes in the lycopene concentration per phospholipid in LDL. These
data
suggest that alpha-tocopherol is a major determinant in protecting LDL
from
oxidation, while lycopene from tomato juice supplementaion may contribute
to
protect phospholipid in LDI, from oxidation. Thus, oral intake of lycopene
might
be beneficial for ameliorating atherosclerosis.
17. Br J Nutr. 2001 Jun;85(6):749-54.
Low serum lycopene concentration is associated with an excess incidence
of acute
coronary events and stroke: the Kuopio Ischaemic Heart Disease Risk Factor
Study.
Rissanen TH, Voutilainen S, Nyyssonen K, Lakka TA, Sivenius J, Salonen
R, Kaplan
GA, Salonen JT.
Research Institute of Public Health, University of Kuopio, PO Box 1627,
FIN-70211, Kuopio, Finland.
A number of epidemiological studies have shown an association between
beta-carotene and the risk of cardiovascular diseases, whereas only a
few
studies are available concerning the association of lycopene with the
risk of
coronary events, and no studies have been undertaken concerning lycopene
and
stroke. Thus, we tested the hypothesis that low serum levels of lycopene
are
associated with increased risk of acute coronary events and stroke in
middle-aged men previously free of CHD and stroke. The subjects were 725
men
aged 46-64 years examined in 1991-3 in the Kuopio Ischaemic Heart Disease
Risk
Factor Study. Forty-one men had either a fatal or a non-fatal acute coronary
event or a stroke by December 1997. In a Cox' proportional hazard's model
adjusting for examination years, age, systolic blood pressure and three
nutritional factors (serum folate, beta-carotene and plasma vitamin C),
men in
the lowest quarter of serum lycopene levels (< or =0.07 micromol/l)
had a
3.3-fold (95 % CI 1.7, 6.4, risk of acute coronary events or stroke compared
with the others. Our study suggests that a low serum level of lycopene
is
associated with an increased risk of atherosclerotic vascular events in
middle-aged men previously free of CHD and stroke.
18. Arterioscler Thromb Vasc Biol. 2000 Dec;20(12):2677-81.
Low plasma lycopene concentration is associated with increased intima-media
thickness of the carotid artery wall.
Rissanen T, Voutilainen S, Nyyssonen K, Salonen R, Salonen JT.
Research Institute of Public Health, University of Kuopio, Kuopio, Finland.
Although a number of epidemiological studies have evaluated the association
between ss-carotene and the risk of cardiovascular diseases, there has
been
little research on the role of lycopene, an acyclic form of ss-carotene,
with
regard to the risk of cardiovascular disease. We investigated the relationship
between plasma concentrations of lycopene and intima-media thickness of
the
common carotid artery wall (CCA-IMT) in 520 middle-aged men and women
(aged 45
to 69 years) in eastern Finland. They were examined from 1994 to 1995
at the
baseline of the Antioxidant Supplementation in Atherosclerosis Prevention
(ASAP)
study, a randomized trial concerning the effect of vitamin E and C
supplementation on atherosclerotic progression. The subjects were classified
into 2 categories according to the median concentration of plasma lycopene
(0.12
micromol/L in men and 0.15 micromol/L in women). Mean CCA-IMT of the right
and
left common carotid arteries was 1.18 mm in men and 0.95 mm in women with
plasma
lycopene levels lower than the median and 0.97 mm in men (P:<0.001
for
difference) and 0.89 mm in women (P:=0.027 for difference) with higher
levels of
plasma lycopene. In ANCOVA adjusting for cardiovascular risk factors and
intake
of nutrients, in men, low levels of plasma lycopene were associated with
a 17.8%
increment in CCA-IMT (P:=0.003 for difference). In women, the difference
did not
remain significant after the adjustments. We conclude that low plasma
lycopene
concentrations are associated with early atherosclerosis, manifested as
increased CCA-IMT, in middle-aged men living in eastern Finland.
Sources
19. J Nutr. 2003 Apr;133(4):1043-50.
Consumption of watermelon juice increases plasma concentrations of lycopene
and
beta-carotene in humans.
Edwards AJ, Vinyard BT, Wiley ER, Brown ED, Collins JK, Perkins-Veazie
P, Baker
RA, Clevidence BA.
U.S. Department of Agriculture, Agricultural Research Service, Phytonutrients
Laboratory, Beltsville Human Nutrition Research Center, MD 20705, USA.
Watermelon is a rich natural source of lycopene, a carotenoid of great
interest
because of its antioxidant capacity and potential health benefits. Assessment
of
bioavailability of lycopene from foods has been limited to tomato products,
in
which heat processing promotes lycopene bioavailability. We examined the
bioavailability of lycopene from fresh-frozen watermelon juice in a 19-wk
crossover study. Healthy, nonsmoking adults (36-69 y) completed three
3-wk
treatment periods, each with a controlled, weight-maintenance diet. Treatment
periods were preceded by "washout" periods of 2-4 wk during
which lycopene-rich
foods were restricted. All 23 subjects consumed the W-20 (20.1 mg/d lycopene,
2.5 mg/d beta-carotene from watermelon juice) and C-0 treatments (controlled
diet, no juice). As a third treatment, subjects consumed either the W-40
(40.2
mg/d lycopene, 5.0 mg/d beta-carotene from watermelon juice, n = 12) or
T-20
treatment (18.4 mg/d lycopene, 0.6 mg/d beta-carotene from tomato juice,
n =
10). After 3 wk of treatment, plasma lycopene concentrations for the W-20,
W-40,
T-20 and C-0 treatments were (least squares means +/- SEM) 1078 +/- 106,
1183
+/- 139, 960 +/- 117 and 272 +/- 27 nmol/L, respectively. Plasma concentrations
of beta-carotene were significantly greater after W-20 (574 +/- 49 nmol/L)
and
W-40 (694 +/- 73 nmol/L) treatments than after the C-0 treatment (313
+/- 27
nmol/L). Plasma lycopene concentrations did not differ at wk 3 after W-20,
W-40
and T-20 treatments, indicating that lycopene was bioavailable from both
fresh-frozen watermelon juice and canned tomato juice, and that a dose-response
effect was not apparent in plasma when the watermelon dose was doubled.
20. J Agric Food Chem. 2002 Apr 10;50(8):2214-9.
Liquid chromatography-mass spectrometry of cis- and all-trans-lycopene
in human
serum and prostate tissue after dietary supplementation with tomato sauce.
van Breemen RB, Xu X, Viana MA, Chen L, Stacewicz-Sapuntzakis M, Duncan
C, Bowen
PE, Sharifi R.
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy,
University of Illinois at Chicago, Chicago, Illinois 60612, USA. breemen@uic.edu
Several epidemiological studies suggest a lower incidence of prostate
cancer in
men who routinely consume tomato products. Tomatoes are the primary dietary
source of lycopene, which is among the most potent antioxidants of the
carotenoids. Men with clinical stage T1 or T2 prostate adenocarcinoma
were
recruited (n = 32) and consumed tomato sauce based pasta dishes for 3
weeks
(equivalent to 30 mg of lycopene per day) before radical prostectomy.
Prostate
tissue from needle biopsy just before intervention and prostectomy after
supplementation from a subset of 11 subjects was evaluated for both total
lycopene and lycopene geometrical isomer ratios. A gradient HPLC system
using a
C(18) column with UV-vis absorbance detection was used to measure total
lycopene. Because the absorbance detector was insufficiently sensitive,
HPLC
with a C(30) column and positive ion atmospheric pressure chemical ionization
mass spectrometric (LC-MS) detection was developed as a new assay to measure
the
ratio of lycopene cis/trans isomers in these samples. The limit of detection
of
the LC-MS method was determined to be 0.93 pmol of lycopene on-column,
and a
linear response was obtained over 3 orders of magnitude. Total lycopene
in serum
increased 2.0-fold from 35.6 to 69.9 microg/dL (from 0.664 to 1.30 microM)
as a
result of dietary supplementation with tomato sauce, whereas total lycopene
in
prostate tissue increased 3.0-fold from 0.196 to 0.582 ng/mg of tissue
(from
0.365 to 1.09 pmol/mg). all-trans-Lycopene and at least 14 cis-isomer
peaks were
detected in prostate tissue and serum. The mean proportion of all-trans-lycopene
in prostate tissue was approximately 12.4% of total lycopene before
supplementation but increased to 22.7% after dietary intervention with
tomato
sauce. In serum there was only a 2.8% but statistically significant increase
in
the proportion of all-trans-lycopene after intervention. These results
indicate
that short-term supplementation with tomato sauce containing primarily
all-trans-lycopene (83% of total lycopene) results in substantial increases
in
total lycopene in serum and prostate and a substantial increase in
all-trans-lycopene in prostate but relatively less in serum.
Antioxidant
21. Biochem Biophys Res Commun. 2003 Apr 11;303(3):745-50.
Lycopene attenuates arachidonic acid toxicity in HepG2 cells overexpressing
CYP2E1.
Xu Y, Leo MA, Lieber CS.
Alcohol Research and Treatment Center, Section of Liver Disease and Nutrition,
Veterans Affairs Medical Center (151-2), Mt Sinai School of Medicine,
130 West
Kingsbridge Rd, Bronx, NY, USA.
Arachidonic acid (AA) was shown to be toxic to HepG2 cells expressing
cytochrome
P4502E1 (CYP2E1) because of oxidative stress. The aim of this study was
to
investigate whether lycopene, a carotenoid with high anti-oxidant capacity,
protects HepG2 cells expressing CYP2E1 against AA toxicity. In preliminary
experiments, lycopene as well as placebo (vehicle) were not toxic in the
three
types of cells tested: HepG2 cells, HepG2 cells transfected with pCI-neo
(Neo)
or pCI-neo/2E1 (2E1). AA produced toxic effects, especially in the 2E1
cells,
and caused a remarkable increase in hydrogen peroxide production and lipid
peroxidation compared to the Neo and HepG2 cells. Lycopene had a protective
effect whereas the placebo did not. This was due, at least in part, to
inhibition of hydrogen peroxide production and of the resulting lipid
peroxidation, confirming the potent anti-oxidant properties of lycopene
and its
suitability for clinical studies.
22. J Nutr. 2003 Mar;133(3):727-32.
The consumption of processed tomato products enhances plasma lycopene
concentrations in association with a reduced lipoprotein sensitivity to
oxidative damage.
Hadley CW, Clinton SK, Schwartz SJ.
The Department of Food Science and Technology, The James Cancer Hospital
and
Solove Research Institute, Columbus, OH 43210, USA.
Lycopene, the predominant carotenoid in tomatoes, is hypothesized to
mediate the
health benefits of tomato products. We designed a study to examine the
change in
plasma lycopene and resistance of lipoproteins to ex vivo oxidative stress.
Healthy individuals (n = 60; age >40 y; 30 men/30 women) consumed a
lycopene-free diet for 1 wk and were subsequently randomized to receive
35 +/-
1, 23 +/- 1 or 25 +/- 1 mg lycopene/d from Campbell's Condensed Tomato
Soup
(CS), Campbell's Ready To Serve Tomato Soup (RTS) or V8 Vegetable Juice
(V8),
respectively, for 15 d. Total plasma lycopene concentrations decreased
from
0.499 +/- 0.044 to 0.322 +/- 0.027 (35%, P < 0.0001) micro mol/L for
the 60
participants during the 7-d washout period. After intervention, total
lycopene
concentrations increased for those consuming CS, RTS and V8 (compared
with the
washout period for each group) to 0.784 +/- 0.083 (123%, P < 0.0001),
0.545 +/-
0.061 (57%, P < 0.01) and 0.569 +/- 0.061 (112%, P < 0.0001) micro
mol/L,
respectively. The concentrations of all lycopene isomers decreased during
the
washout period. As a percentage of plasma total lycopene isomers for the
60
subjects, all-trans-lycopene decreased from 44.4 +/- 1.2 to 39.6 +/- 1.2
(P <
0.0001), whereas total cis-lycopene isomers increased from 55.6 +/- 1.2
to 60.4
+/- 1.2 (P < 0.0001) during the washout period, a shift that was reversed
by
consumption of tomato products for 15 d. The ex vivo lipoprotein oxidation
lag
period, used as a measure of antioxidant capacity, increased significantly
from
64.7 +/- 2.4 min at the end of the washout period (all groups) to 70.1
+/- 4.0
(P < 0.05), 68.3 +/- 2.4 (P < 0.05) and 71.7 +/- 4.0 min (P <
0.01) after
treatment for the CS, RTS and V8 groups, respectively. This study shows
that
lycopene concentrations and isomer patterns change rapidly with variation
in
dietary intake. In addition, 15 d of tomato product consumption significantly
enhanced the protection of lipoproteins to ex vivo oxidative stress.
23. Eur J Nutr. 2002 Dec;41(6):237-43.
Paraoxonase 1 Q192R (PON1-192) polymorphism is associated with reduced
lipid
peroxidation in R-allele-carrier but not in QQ homozygous elderly subjects
on a
tomato-rich diet.
Bub A, Barth S, Watzl B, Briviba K, Herbert BM, Luhrmann PM, Neuhauser-Berthold
M, Rechkemmer G.
Federal Research Centre for Nutrition, Institute of Nutritional Physiology,
Haid-und-Neu-Str. 9, 76131 Karlsruhe, Germany. achim.bub@bfe.uni-karlsruhe.de
BACKGROUND: The oxidative modification of LDL is considered to play a
central
role in the pathogenesis of atherosclerosis and coronary heart disease
(CHD).
Paraoxonase (PON1) protects LDL from oxidation and may therefore retard
the
development of atherosclerosis. The PON1-192 polymorphism is associated
with
diminished PON1 concentrations and an increased risk for CHD in RR-allele
subjects. AIM OF THE STUDY: To investigate the effect of tomato juice
consumption on PON1 activity and other parameters related to oxidative
stress in
healthy elderly subjects. Furthermore, the PON1-192 genotype has been
determined
in the volunteers in order to see whether possible treatment effects are
related
to the PON1-192 polymorphism. METHODS: Fifty elderly subjects were randomly
assigned to control (mineral water) or intervention group (tomato juice).
Subjects of the tomato juice group consumed daily 330 mL tomato juice
for 8
weeks. Antioxidant status was measured as LDL oxidation, plasma malondialdehyde,
ferric reducing ability of plasma (FRAP) and PON1 activity. The PON1-192
polymorphism was determined by restriction fragment length polymorphism
polymerase chain reaction (RFLP-PCR). Plasma carotenoids were analyzed
by HPLC.
RESULTS: Tomato juice consumption reduced LDL-oxidation and improved antioxidant
status in R-allele carriers, but not in the QQ genotype group. PON1 activity
increased irrespective of the genotype in both, control and intervention
group.
CONCLUSIONS: The changes in antioxidant status after tomato juice consumption
seem to depend on the PON1-192 genotype. Healthy elderly, carrying the
R-allele,
could specifically reduce their higher cardiovascular risk by changing
dietary
habits.
24. Free Radic Res. 2002 Aug;36(8):875-82.
Independent and interactive association of blood antioxidants and oxidative
damage in elderly people.
Lasheras C, Huerta JM, Gonzalez S, Brana AF, Patterson AM, Fernandez
S.
Departamento de Biologia Funcional, Facultad de Medicina, Universidad
de Oviedo,
Spain. lasheras@correo.uniovi.es
Oxidative stress is recognized as one of the major contributors to the
increased
risk of several diseases. Many recent population studies have established
a
close link between antioxidant defense and lowered risk of morbidity and
mortality from cancer and heart disease, but little is known about the
cooperative interactions of antioxidants. We examined the cross-sectional
independent and interactive association of serum lipid-soluble antioxidant
levels and free radical scavenging enzymes to serum malondialdehyde (MDA)
levels, as a marker of oxidative damage. The participants were 160 nonsmoker
institutionalized elderly. Upper tertile values of
erythrocyte-superoxide-dismutase (E-SOD) constituted the strongest-associated
single compound with a 74% decreased risk of high MDA. Upper tertiles
of
carotenoids and alpha-tocopherol independently showed a similar lowering
of risk
of about 57%. The highest tertiles of lycopene and either beta-carotene
or
alpha-tocopherol simultaneously reveal a higher decreased risk for oxidative
damage (74 and 71%, respectively), very similar to those in the upper
tertiles
of all these three vitamins (75%). This study represents one of the few
attempts
to date to understand the interactive effect between antioxidants and
suggests
that lipid-soluble antioxidants act not individually, but rather cooperatively
with each other. The efficacy of this interaction is more effective when
lycopene is present.
25. J Photochem Photobiol B. 2001 Nov 15;64(2-3):176-8.
Dietary uptake of lycopene protects human cells from singlet oxygen and
nitrogen
dioxide - ROS components from cigarette smoke.
Bohm F, Edge R, Burke M, Truscott TG.
Meclinic Berlin, Friedrichstrasse 71, 10117 Berlin, Germany. info@meoclinic.de
There is current interest in the health benefits of dietary carotenoids
and the
possible deleterious effects on certain sub-populations such as smokers.
Here we
report in vivo protection of human lymphocytes, conferred by dietary
supplementation of lycopene rich foods against the reactive oxygen species,
NO(2)(*) radical (by electron transfer) and 1(O)(2) (by energy transfer).
It was
found that a lycopene rich diet, maintained for 14 days, increased the
serum
lycopene level 10 fold compared to serum obtained after the same period,
where a
typical western European diet had been consumed. Relative lymphocyte protection
factors of 17.6 and 6.3 against NO(2)(*) radical and 1(O)(2), respectively,
were
obtained, which re-enforce epidemiological data, showing protection against
several chronic diseases by tomato lycopene.
26. Eur J Nutr. 2001 Apr;40(2):78-83.
Relationship between dietary intake, antioxidant status and smoking habits
in
female Austrian smokers.
Rust P, Lehner P, Elmadfa I.
Institute of Nutritional Sciences, Vienna, Austria. petra.rust@univie.ac.at
BACKGROUND: Previous studies have shown that cigarette smoke contains
many
oxidants and free radicals, which can increase lipid peroxidation. AIM
OF THE
STUDY: The association between smoking, food pattern, especially vitamin
intake
and plasma concentrations of important antioxidants, as well as lipid
peroxidation products was assessed in this cross-sectional study. SUBJECTS
and
METHODS: Sixty Austrian women aged 18-40 y were enrolled in the study.
Twenty-nine women were allocated to the smoking group; thirty-one women
served
as nonsmoking controls. Plasma concentrations of alpha- and gamma-tocopherol,
alpha- and beta-carotene, lycopene, cryptoxanthin, retinol, ascorbate
and
malondialdehyde were determined by HPLC; dietary intake and food pattern
had
been assessed by four 24-h dietary intake recalls and one food frequency
questionnaire. RESULTS: Generally, food intake patterns were not different
between smoking and nonsmoking women. But, a significantly higher intake
of
alcohol was observed in the smoking group (P < 0.05). Plasma ascorbic
acid
concentration of the smoking group did not differ from the nonsmoking
women.
Despite the increased utilization because of the oxidative stress in smokers,
this result might be explained by the high dietary intake of vitamin C
in our
smoking group. Significantly lower plasma concentrations of alpha-,beta-carotene
and lycopene have been partly ascribed to the enhanced metabolic turnover
resulting from smoking-induced oxidative stress. Our results confirm that
smoking had no effects on plasma tocopherol and plasma retinol concentrations.
CONCLUSIONS: The poor supply with the carotenoids alpha-, beta-carotene
and
lycopene may result from the increased metabolism of antioxidants caused
by
oxidative stress and may be responsible for significantly higher levels
of lipid
peroxidation products in smokers compared to nonsmokers (P < 0.05).
27. Free Radic Biol Med. 2000 Nov 15;29(10):1051-5.
Consumption of tomato products with olive oil but not sunflower oil increases
the antioxidant activity of plasma.
Lee A, Thurnham DI, Chopra M.
Northern Ireland Centre for Diet and Health, School of Biomedical Sciences,
University of Ulster, Northern Ireland, Coleraine, UK.
Health benefits of lycopene from tomato products have been suggested
to be
related to its antioxidant activity. Dietary fat may influence the absorption
and hence the plasma levels and antioxidant activity of lycopene. In the
present
study, we have compared the effect of consumption of tomato products with
extra-virgin olive oil vs. tomato products plus sunflower oil on plasma
lycopene
and antioxidant levels. Results show that the oil composition does not
affect
the absorption of lycopene from tomato products because similar levels
of plasma
lycopene (mean +/- SD) were obtained on feeding tomatoes (providing
approximately 46 mg lycopene/d) for 7 d with either olive oil (0.66 +/-
0.26 vs
1.20 +/- 0.20 micromol/l, p <.002) or sunflower oil (0.67 +/- 0.27
vs. 1.14
micromol/l, p <.001). However, consumption of tomato products with
olive oil
significantly raised the plasma antioxidant activity (FRAP) from 930 +/-
150 to
1118 +/- 184 micromol/l, p <.01) but no effect was observed when the
sunflower
oil was used. The change (supplementation minus start values) in FRAP
following
the consumption of tomato products with oil was significantly higher for
olive
oil (190 +/- 101) than for sunflower oil (-9.6 +/- 99, p <. 005). In
conclusion,
the results of the study show that consumption of tomato products with
olive oil
but not with sunflower oil improves the antioxidant activity of the plasma.
28. Arch Latinoam Nutr. 1999 Sep;49(3 Suppl 1):12S-20S.
Lycopene entrapped in human albumin protects 2'-deoxyguanosine against
singlet
oxygen damage.
Yamaguchi LF, Martinez GR, Catalani LH, Medeiros MH, Di Mascio P.
Departamento de Bioquimica, Universidade de Sao Paulo, Brasil.
The generation of electronically excited molecular oxygen 1O2 has been
shown to
occur in several biological systems, such as photooxidation of a variety
of
biological compounds and xenobiotics ("photodynamic action")
and also enzymatic
reactions. The high reactivity of 1O2 with unsaturated compounds, sulfides
and
amino groups arises from its electrophilicity and relatively long lifetime.
Thus, biological targets for 1O2 having the above functional groups include
unsaturated fatty acids, proteins, enzymes and DNA. There is interest
in the
role of nutrition in the prevention and pathogenesis of cancer. Epidemiological
studies in humans have suggested that carotenoids aid in cancer prevention.
Lycopene and oxycarotenoids are present at significant levels in cells
and
plasma. Extensively conjugated biomolecules such as carotenoids act largely
on
physical quenching of 1O2 and in much lesser extent on chemical reaction.
In
this study we observed the protective effect of beta-carotene and lycopene
entrapped in human albumin (HSA) against the oxidative 1O2 attack of
2'-deoxyguanosine (dGuo). Photosensitization with methylene blue associated
with
Chelex resine or Polymer-Rose bengal (Sensitox) and thermodecomposition
of
water-soluble endoperoxide 3,3'-(1,4-naphthylidene)dipropionate were employed
to
generate 1O2. The detection of 8-oxo-7,8-dihydro-2'-deoxyguanosine(8-oxodGuo)
and 4-hydroxy-8-oxo-7,8-dihydro-2'-deoxyguanosine(4-OH-8-oxodGuo) were
performed
using reversed phase HPLC with UV, electrochemical detection and by electrospray
ionization mass spectrometry. Results showed a significant decrease in
the
amount of 8-oxodGuo in the presence of lycopene. The percentages of
4-OH-8-oxodGuo and 8-oxodGuo measured were 50% and 70% lower than the
control,
respectively. These data indicate that carotenoids entrapped in albumin
can be
an efficient quencher of 1O2 and may be of interest in protecting against
the
deleterious effect of this excited state molecule.
29. J Nutr. 2000 Feb;130(2):189-92.
Lymphocyte lycopene concentration and DNA protection from oxidative damage
is
increased in women after a short period of tomato consumption.
Porrini M, Riso P.
Department of Food Science and Technology, University of Milan, Italy.
Several epidemiologic studies have suggested a role of tomato products
in
protecting against cancer and chronic diseases. In nine adult women, we
evaluated whether the consumption of 25 g tomato puree (containing 7 mg
lycopene
and 0.3 mg beta-carotene) for 14 consecutive days increased plasma and
lymphocyte carotenoid concentration and whether this was related to an
improvement in lymphocyte resistance to an oxidative stress (500 micromol/L
hydrogen peroxide for 5 min). Before and after the period of tomato intake,
carotenoid concentrations were analyzed by HPLC and lymphocyte resistance
to
oxidative stress by the Comet assay, which detects DNA strand breaks.
Intake of
tomato puree increased plasma (P <0.001) and lymphocyte (P<0.005)
lycopene
concentration and reduced lymphocyte DNA damage by approximately 50% (P<0.0001).
Beta-carotene concentration increased in plasma (P<0.05) but not in
lymphocytes
after tomato puree consumption. An inverse relationship was found between
plasma
lycopene concentration (r = -0.82, P<0.0001) and lymphocyte lycopene
concentration (r = -0.62, P<0.01) and the oxidative DNA damage. In
conclusion,
small amounts of tomato puree added to the diet over a short period can
increase
carotenoid concentrations and the resistance of lymphocytes to oxidative
stress.
30. Am J Clin Nutr. 1999 Apr;69(4):712-8.
Does tomato consumption effectively increase the resistance of lymphocyte
DNA to
oxidative damage?
Riso P, Pinder A, Santangelo A, Porrini M.
Department of Food Science and Technology, University of Milan, Italy.
nutr_lab@imiucca.csi.unimi.it
BACKGROUND: Lycopene, the main carotenoid in tomato, has been shown to
be a
potent antioxidant in vitro. However, there is no significant evidence
of its
antioxidant action in vivo. OBJECTIVE: We evaluated the effect of tomato
intake
on plasma carotenoid concentrations and lymphocyte resistance to oxidative
stress. DESIGN: Ten healthy women (divided into 2 groups of 5 subjects
each) ate
a diet containing tomato puree (providing 16.5 mg lycopene) and a tomato-free
diet for 21 d each in a crossover design. Before and after each diet period,
plasma carotenoid concentrations and primary lymphocyte resistance to
oxidative
stress (evaluated by means of single-cell gel electrophoresis) were analyzed.
RESULTS: After the first 21-d experimental period, total plasma lycopene
concentrations increased by 0.5 micromol/L (95% CI: 0.14, 0.87) in the
group
that consumed the tomato diet and decreased by 0.2 micromol/L (95% CI:
-0.11,
-0.30) in the group that consumed the tomato-free diet (P < 0.001).
Tomato
consumption also had an effect on cellular antioxidant capacity: lymphocyte
DNA
damage after ex vivo treatment with hydrogen peroxide decreased by 33%
(95% CI:
0.8%, 61%; P < 0.05) and by 42% (95% CI: 5.1%, 78%; P < 0.05) in
the 2 groups of
subjects after consumption of the tomato diet. CONCLUSION: The consumption
of
tomato products may reduce the susceptibility of lymphocyte DNA to oxidative
damage.
Prostate Cancer
31. J Med Food. 2002 Winter;5(4):181-7.
Effect of lycopene on prostate LNCaP cancer cells in culture.
Kim L, Rao AV, Rao LG.
Department of Nutritional Sciences, University of Toronto, Toronto, Ontario,
Canada.
Epidemiological studies have shown an inverse relationship between serum
lycopene levels and the risk of prostate cancer. The objective of this
study was
to measure the effect of lycopene on the proliferation of LNCaP human
prostate
cancer cells in culture. A new, water-dispersible lycopene in an appropriate
vehicle was used. The stock solution was diluted in the medium to obtain
lycopene concentrations of 10(-6), 10(-5), and 10(-4) M; their corresponding
vehicles were similarly diluted to be used as controls. Cells were grown
for 48
hours in RPMI-1640 medium supplemented with 10% fetal bovine serum and
antibiotics. Lycopene was then added at different concentrations, and
the cells
were allowed to grow for 24, 48, 72, and 96 hours. Lycopene at concentrations
of
10(-6) and 10(-5) M significantly reduced the growth of LNCaP cells after
48,
72, and 96 hours of incubation, by 24.4% to 42.8% (P <.05). The inhibitory
effect of lycopene was significantly higher than that of the corresponding
vehicle controls. In a follow-up experiment, a lower range of lycopene
concentrations (10(-9) to 10(-7) M) was used to determine whether there
was a
dose-response effect. Lycopene significantly decreased the growth of cells
in a
dose-dependent manner when cells were incubated for 24, 48, 72, or 96
hours (F =
3.150, 11.27, 54.51, and 297.5, respectively; P <.05). The growth inhibitory
effect of lycopene on human prostate cancer cells observed in this study
suggests a possibly important role for lycopene as an antioxidant in human
prostate cancer; however, investigations of other mechanisms are warranted.
32. Exp Biol Med (Maywood). 2002 Nov;227(10):881-5.
Effects of lycopene supplementation in patients with localized prostate
cancer.
Kucuk O, Sarkar FH, Djuric Z, Sakr W, Pollak MN, Khachik F, Banerjee
M, Bertram
JS, Wood DP Jr.
Division of Hematology and Oncology, 3990 John R, Barbara Ann Karmanos
Cancer
Institute, Wayne State University, 5 Hudson, Detroit, MI 48201, USA.
kucuko@karmanos.org
Epidemiological studies have shown an inverse association between dietary
intake
of lycopene and prostate cancer risk. We conducted a clinical trial to
investigate the biological and clinical effects of lycopene supplementation
in
patients with localized prostate cancer. Twenty-six men with newly diagnosed
prostate cancer were randomly assigned to receive a tomato oleoresin extract
containing 30 mg of lycopene (n = 15) or no supplementation (n = 11) for
3 weeks
before radical prostatectomy. Biomarkers of cell proliferation and apoptosis
were assessed by Western blot analysis in benign and cancerous prostate
tissues.
Oxidative stress was assessed by measuring the peripheral blood lymphocyte
DNA
oxidation product 5-hydroxymethyl-deoxyuridine (5-OH-mdU). Usual dietary
intake
of nutrients was assessed by a food frequency questionnaire at baseline.
Prostatectomy specimens were evaluated for pathologic stage, Gleason score,
volume of cancer, and extent of high-grade prostatic intraepithelial neoplasia.
Plasma levels of lycopene, insulin-like growth factor-1, insulin-like
growth
factor binding protein-3, and prostate-specific antigen were measured
at
baseline and after 3 weeks of supplementation or observation. After
intervention, subjects in the intervention group had smaller tumors (80%
vs 45%,
less than 4 ml), less involvement of surgical margins and/or extra-prostatic
tissues with cancer (73% vs 18%, organ-confined disease), and less diffuse
involvement of the prostate by high-grade prostatic intraepithelial neoplasia
(33% vs 0%, focal involvement) compared with subjects in the control group.
Mean
plasma prostate-specific antigen levels were lower in the intervention
group
compared with the control group. This pilot study suggests that lycopene
may
have beneficial effects in prostate cancer. Larger clinical trials are
warranted
to investigate the potential preventive and/or therapeutic role of lycopene
in
prostate cancer.
33. Am J Epidemiol. 2002 Jun 1;155(11):1023-32.
Serum lycopene, other serum carotenoids, and risk of prostate cancer
in US
Blacks and Whites.
Vogt TM, Mayne ST, Graubard BI, Swanson CA, Sowell AL, Schoenberg JB,
Swanson
GM, Greenberg RS, Hoover RN, Hayes RB, Ziegler RG.
Department of Epidemiology and Public Health, Yale University School
of
Medicine, New Haven, CT, USA. vogtt@exchange.nih.gov
Epidemiologic studies investigating the relation between individual carotenoids
and risk of prostate cancer have produced inconsistent results. To further
explore these associations and to search for reasons prostate cancer incidence
is over 50% higher in US Blacks than Whites, the authors analyzed the
serum
levels of individual carotenoids in 209 cases and 228 controls in a US
multicenter, population-based case-control study (1986-1989) that included
comparable numbers of Black men and White men aged 40-79 years. Lycopene
was
inversely associated with prostate cancer risk (comparing highest with
lowest
quartiles, odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.36,
1.15;
test for trend, p = 0.09), particularly for aggressive disease (comparing
extreme quartiles, OR = 0.37, 95% CI: 0.15, 0.94; test for trend, p =
0.04).
Other carotenoids were positively associated with risk. For all carotenoids,
patterns were similar for Blacks and Whites. However, in both the controls
and
the Third National Health and Nutrition Examination Survey, serum lycopene
concentrations were significantly lower in Blacks than in Whites, raising
the
possibility that differences in lycopene exposure may contribute to the
racial
disparity in incidence. In conclusion, the results, though not statistically
significant, suggest that serum lycopene is inversely related to prostate
cancer
risk in US Blacks and Whites.
34. J Natl Cancer Inst. 2002 Mar 6;94(5):391-8.
A prospective study of tomato products, lycopene, and prostate cancer
risk.
Giovannucci E, Rimm EB, Liu Y, Stampfer MJ, Willett WC.
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital
and
Harvard Medical School, Boston, MA, USA. edward.giovannucci@channing.harvard.edu
BACKGROUND: Some data, including our findings from the Health Professionals
Follow-Up Study (HPFS) from 1986 through January 31, 1992, suggest that
frequent
intake of tomato products or lycopene, a carotenoid from tomatoes, is
associated
with reduced risk of prostate cancer. Overall, however, the data are
inconclusive. We evaluated additional data from the HPFS to determine
if the
association would persist. METHODS: We ascertained prostate cancer cases
from
1986 through January 31, 1998, among 47 365 HPFS participants who completed
dietary questionnaires in 1986, 1990, and 1994. We used pooled logistic
regression to compute multivariate relative risks (RR) and 95% confidence
intervals (CIs). All statistical tests were two-sided. RESULTS: From 1986
through January 31, 1998, 2481 men in the study developed prostate cancer.
Results for the period from 1992 through 1998 confirmed our previous
findings---that frequent tomato or lycopene intake was associated with
a reduced
risk of prostate cancer. Similarly, for the entire period of 1986 through
1998,
using the cumulative average of the three dietary questionnaires, lycopene
intake was associated with reduced risk of prostate cancer (RR for high
versus
low quintiles = 0.84; 95% CI = 0.73 to 0.96; P(trend) =.003); intake of
tomato
sauce, the primary source of bioavailable lycopene, was associated with
an even
greater reduction in prostate cancer risk (RR for 2+ servings/week versus
<1
serving/month = 0.77; 95% CI = 0.66 to 0.90; P(trend)<.001), especially
for
extraprostatic cancers (RR = 0.65; 95% CI = 0.42 to 0.99). These associations
persisted in analyses controlling for fruit and vegetable consumption
and for
olive oil use (a marker for Mediterranean diet) and were observed separately
in
men of Southern European or other Caucasian ancestry. CONCLUSION: Frequent
consumption of tomato products is associated with a lower risk of prostate
cancer. The magnitude of the association was moderate enough that it could
be
missed in a small study or one with substantial errors in measurement
or based
on a single dietary assessment.
35. J Natl Cancer Inst. 2001 Dec 19;93(24):1872-9.
Oxidative DNA damage in prostate cancer patients consuming tomato sauce-based
entrees as a whole-food intervention.
Chen L, Stacewicz-Sapuntzakis M, Duncan C, Sharifi R, Ghosh L, van Breemen
R,
Ashton D, Bowen PE.
Department of Human Nutrition, University of Illinois at Chicago, 60612,
USA.
BACKGROUND: Human prostate tissues are vulnerable to oxidative DNA damage.
The
risk of prostate cancer is lower in men reporting higher consumption of
tomato
products, which contain high levels of the antioxidant lycopene. We examined
the
effects of consumption of tomato sauce-based pasta dishes on lycopene
uptake,
oxidative DNA damage, and prostate-specific antigen (PSA) levels in patients
already diagnosed with prostate cancer. METHODS: Thirty-two patients with
localized prostate adenocarcinoma consumed tomato sauce-based pasta dishes
for
the 3 weeks (30 mg of lycopene per day) preceding their scheduled radical
prostatectomy. Serum and prostate lycopene concentrations, serum PSA levels,
and
leukocyte DNA oxidative damage (ratio of 8-hydroxy-2'-deoxyguanosine [8-OHdG]
to
2'-deoxyguanosine [dG]) were assessed before and after the dietary intervention.
DNA oxidative damage was assessed in resected prostate tissue from study
participants and from seven randomly selected prostate cancer patients.
All
statistical tests were two-sided. RESULTS: After the dietary intervention,
serum
and prostate lycopene concentrations were statistically significantly
increased,
from 638 nM (95% confidence interval [CI] = 512 to 764 nM) to 1258 nM
(95% CI =
1061 to 1455 nM) (P<.001) and from 0.28 nmol/g (95% CI = 0.18 to 0.37
nmol/g) to
0.82 nmol/g (95% CI = 0.57 to 1.11 nmol/g) (P <.001), respectively.
Compared
with preintervention levels, leukocyte oxidative DNA damage was statistically
significantly reduced after the intervention, from 0.61 8-OHdG/10(5) dG
(95% CI
= 0.45 to 0.77 8-OHdG/10(5) dG) to 0.48 8-OHdG/ 10(5) dG (95% CI = 0.41
to 0.56
8-OHdG/10(5) dG) (P =.005). Furthermore, prostate tissue oxidative DNA
damage
was also statistically significantly lower in men who had the intervention
(0.76
8-OHdG/10(5) dG [95% CI = 0.55 to 0.96 8-OHdG/10(5) dG]) than in the randomly
selected patients (1.06 8-OHdG/10(5) dG [95% CI = 0.62 to 1.51 8-OHdG/10(5)
dG];
P =.03). Serum PSA levels decreased after the intervention, from 10.9
ng/mL (95%
CI = 8.7 to 13.2 ng/mL) to 8.7 ng/mL (95% CI = 6.8 to 10.6 ng/mL) (P<.001).
CONCLUSION: These data indicate a possible role for a tomato sauce constituent,
possibly lycopene, in the treatment of prostate cancer and warrant further
testing with a larger sample of patients, including a control group.
36. J Nutr. 2001 Dec;131(12):3303-6.
Carotenoids affect proliferation of human prostate cancer cells.
Kotake-Nara E, Kushiro M, Zhang H, Sugawara T, Miyashita K, Nagao A.
Department of Bioresources Chemistry, Graduate School of Fisheries Science,
Hokkaido University, 3-1-1 Hakodate 041-8611, Japan.
We investigated whether various carotenoids present in foodstuffs were
potentially involved in cancer-preventing action on human prostate cancer.
The
effects of 15 kinds of carotenoids on the viability of three lines of
human
prostate cancer cells, PC-3, DU 145 and LNCaP, were evaluated. When the
prostate
cancer cells were cultured in a carotenoid-supplemented medium for 72
h at 20
micromol/L, 5,6-monoepoxy carotenoids, namely, neoxanthin from spinach
and
fucoxanthin from brown algae, significantly reduced cell viability to
10.9 and
14.9% for PC-3, 15.0 and 5.0% for DU 145, and nearly zero and 9.8% for
LNCaP,
respectively. Acyclic carotenoids such as phytofluene, zeta-carotene and
lycopene, all of which are present in tomato, also significantly reduced
cell
viability. On the other hand, phytoene, canthaxanthin, beta-cryptoxanthin
and
zeaxanthin did not affect the growth of the prostate cancer cells. DNA
fragmentation of nuclei in neoxanthin- and fucoxanthin-treated cells was
detected by in situ TdT-mediated dUTP nick end labeling (TUNEL) assay.
Neoxanthin and fucoxanthin were found to reduce cell viability through
apoptosis
induction in the human prostate cancer cells. These results suggest that
ingestion of leafy green vegetables and edible brown algae rich in neoxanthin
and fucoxanthin might have the potential to reduce the risk of prostate
cancer.
37. Cancer Epidemiol Biomarkers Prev. 2001 Aug;10(8):861-8.
Phase II randomized clinical trial of lycopene supplementation before
radical
prostatectomy.
Kucuk O, Sarkar FH, Sakr W, Djuric Z, Pollak MN, Khachik F, Li YW, Banerjee
M,
Grignon D, Bertram JS, Crissman JD, Pontes EJ, Wood DP Jr.
Division of Hematology and Oncology, Wayne State University, and Barbara
Ann
Karmanos Cancer Institute, Detroit, MI 48201, USA. kucuko@karmanos.org
An inverse association has been observed between dietary intake of lycopene
and
the risk of prostate cancer. We investigated the effects of lycopene
supplementation in patients with prostate cancer. Twenty-six men with
newly
diagnosed, clinically localized (14 T(1) and 12 T(2)) prostate cancer
were
randomly assigned to receive 15 mg of lycopene (n = 15) twice daily or
no
supplementation (n = 11) for 3 weeks before radical prostatectomy. Biomarkers
of
differentiation and apoptosis were assessed by Western blot analysis on
benign
and malignant parts of the prostate gland. Prostatectomy specimens were
entirely
embedded, step-sectioned, and evaluated for pathological stage, Gleason
score,
volume of cancer, and extent of high-grade prostatic intraepithelial neoplasia.
Plasma levels of lycopene, insulin-like growth factor-1 (IGF-1), IGF binding
protein-3, and prostate-specific antigen were measured at baseline and
after 3
weeks of supplementation or observation. Eleven (73%) subjects in the
intervention group and two (18%) subjects in the control group had no
involvement of surgical margins and/or extra-prostatic tissues with cancer
(P =
0.02). Twelve (84%) subjects in the lycopene group and five (45%) subjects
in
the control group had tumors <4 ml in size (P = 0.22). Diffuse involvement
of
the prostate by high-grade prostatic intraepithelial neoplasia was present
in 10
(67%) subjects in the intervention group and in 11 (100%) subjects in
the
control group (P = 0.05). Plasma prostate-specific antigen levels decreased
by
18% in the intervention group, whereas they increased by 14% in the control
group (P = 0.25). Expression of connexin 43 in cancerous prostate tissue
was
0.63 +/- 0.19 absorbance in the lycopene group compared with 0.25 +/-
0.08 in
the control group (P = 0.13). Expression of bcl-2 and bax did not differ
significantly between the two study groups. IGF-1 levels decreased in
both
groups (P = 0.0002 and P = 0.0003, respectively). The results suggest
that
lycopene supplementation may decrease the growth of prostate cancer. However,
no
firm conclusions can be drawn at this time because of the small sample
size.
38. Altern Med Rev. 1999 Jun;4(3):162-9.
An ecologic study of dietary links to prostate cancer.
Grant WB.
NASA Langley Research Center, Hampton, VA, USA. wbgrant@norfolk.infi.net
BACKGROUND: The etiology of prostate cancer has not been fully resolved
in the
scientific and medical literature, although the non-fat portion of milk
and
calcium are emerging as leading dietary risk factors, with lycopene (found
in
tomatoes) and vitamin D apparently being risk reduction factors. METHODS:
The
ecologic (multi-country statistical) approach is used to study dietary
links to
prostate cancer. Mortality data from 1986 for various age groups in 41
countries
are compared with national consumer macronutrient supply values for 1983
and
tomato supply values for 1985. RESULTS: For 28 countries with more than
five
Kcal/day of tomatoes in the consumer supply, a linear combination of non-fat
milk (risk factor) and tomatoes (risk reduction factor) was found to have
the
highest statistical association with prostate cancer mortality rates for
men
over the age of 35, with the Pearson regression coefficient (R2) for those
aged
65-74 years = 0.67 and p < 0.001. For the 13 countries with fewer than
six
Kcal/day of tomatoes, non-fat milk had the highest association (R2 = 0.92,
p <
0.001 for men aged 65-74 years). For 41 countries combined, the non-fat
portion
of milk had the highest association with prostate cancer mortality rates
(R2 =
0.73, p < 0.001 for men aged 65-74 years). CONCLUSIONS: These results
support
the results of several cohort studies which found the non-fat portion
of milk to
have the highest association with prostate cancer, likely due to the calcium,
and tomatoes to reduce the risk of prostate cancer, most likely due to
lycopene.
39. Nutr Cancer. 1999;33(2):159-64.
Serum and tissue lycopene and biomarkers of oxidation in prostate cancer
patients: a case-control study.
Rao AV, Fleshner N, Agarwal S.
Department of Nutritional Sciences, Faculty of Medicine, University of
Toronto,
ON, Canada. v.rao@utoronto.ca
Dietary intake of tomatoes and tomato products containing lycopene, an
antioxidant carotenoid, has been shown in recent studies to reduce the
risk of
cancer. This study was conducted to investigate the serum and prostate
tissue
lycopene and other major carotenoid concentrations in cancer patients
and their
controls. Serum lipid and protein oxidation was also measured. Twelve
prostate
cancer patients and 12 age-matched subjects were used in the study.
Significantly lower serum and tissue lycopene levels (44%, p = 0.04; 78%,
p =
0.050, respectively) were observed in the cancer patients than in their
controls. Serum and tissue beta-carotene and other major carotenoids did
not
differ between the two groups (p = 0.395 and p = 0.280, respectively).
Although
there was no difference (p = 0.760) in serum lipid peroxidation between
cancer
patients and their controls (7.09 +/- 0.74 and 6.81 +/- 0.56 mumol/l,
respectively), serum protein thiol levels were significantly lower among
the
cancer patients (p = 0.026). This study demonstrates that the status of
lycopene
but not other carotenoids in prostate cancer patients is different from
controls. The role of dietary lycopene in preventing oxidative damage
of
biomolecules and thereby reducing the risk of prostate cancer needs to
be
evaluated in future studies.
40. Cancer Res. 1999 Mar 15;59(6):1225-30.
Lower prostate cancer risk in men with elevated plasma lycopene levels:
results
of a prospective analysis.
Gann PH, Ma J, Giovannucci E, Willett W, Sacks FM, Hennekens CH, Stampfer
MJ.
Department of Preventive Medicine, Northwestern University Medical School,
Chicago, Illinois 60611, USA. pgann@nwu.edu
Dietary consumption of the carotenoid lycopene (mostly from tomato products)
has
been associated with a lower risk of prostate cancer. Evidence relating
other
carotenoids, tocopherols, and retinol to prostate cancer risk has been
equivocal. This prospective study was designed to examine the relationship
between plasma concentrations of several major antioxidants and risk of
prostate
cancer. We conducted a nested case-control study using plasma samples
obtained
in 1982 from healthy men enrolled in the Physicians' Health Study, a randomized,
placebo-controlled trial of aspirin and beta-carotene. Subjects included
578 men
who developed prostate cancer within 13 years of follow-up and 1294 age-
and
smoking status-matched controls. We quantified the five major plasma carotenoid
peaks (alpha- and beta-carotene, beta-cryptoxanthin, lutein, and lycopene)
plus
alpha- and gamma-tocopherol and retinol using high-performance liquid
chromatography. Results for plasma beta-carotene are reported separately.
Odds
ratios (ORs), 95% confidence intervals (Cls), and Ps for trend were calculated
for each quintile of plasma antioxidant using logistic regression models
that
allowed for adjustment of potential confounders and estimation of effect
modification by assignment to either active beta-carotene or placebo in
the
trial. Lycopene was the only antioxidant found at significantly lower
mean
levels in cases than in matched controls (P = 0.04 for all cases). The
ORs for
all prostate cancers declined slightly with increasing quintile of plasma
lycopene (5th quintile OR = 0.75, 95% CI = 0.54-1.06; P, trend = 0.12);
there
was a stronger inverse association for aggressive prostate cancers (5th
quintile
OR = 0.56, 95% CI = 0.34-0.91; P, trend = 0.05). In the placebo group,
plasma
lycopene was very strongly related to lower prostate cancer risk (5th
quintile
OR = 0.40; P, trend = 0.006 for aggressive cancer), whereas there was
no
evidence for a trend among those assigned to beta-carotene supplements.
However,
in the beta-carotene group, prostate cancer risk was reduced in each lycopene
quintile relative to men with low lycopene and placebo. The only other
notable
association was a reduced risk of aggressive cancer with higher alpha-tocopherol
levels that was not statistically significant. None of the associations
for
lycopene were confounded by age, smoking, body mass index, exercise, alcohol,
multivitamin use, or plasma total cholesterol level. These results concur
with a
recent prospective dietary analysis, which identified lycopene as the
carotenoid
with the clearest inverse relation to the development of prostate cancer.
The
inverse association was particularly apparent for aggressive cancer and
for men
not consuming beta-carotene supplements. For men with low lycopene,
beta-carotene supplements were associated with risk reductions comparable
to
those observed with high lycopene. These data provide further evidence
that
increased consumption of tomato products and other lycopene-containing
foods
might reduce the occurrence or progression of prostate cancer.
41. Biochem Biophys Res Commun. 1998 Sep 29;250(3):582-5.
Lycopene in association with alpha-tocopherol inhibits at physiological
concentrations proliferation of prostate carcinoma cells.
Pastori M, Pfander H, Boscoboinik D, Azzi A.
Institute for Biochemistry and Molecular Biology, University of Bern,
Bern,
CH-3012, Switzerland.
The effect of lycopene alone or in association with other antioxidants
was
studied on the growth of two different human prostate carcinoma cell lines
(the
androgen insensitive DU-145 and PC-3). It was found that lycopene alone
was not
a potent inhibitor of prostate carcinoma cell proliferation. However,
the
simultaneous addition of lycopene together with alpha-tocopherol, at
physiological concentrations (less than 1 microM and 50 microM, respectively),
resulted in a strong inhibitory effect of prostate carcinoma cell proliferation,
which reached values close to 90 %. The effect of lycopene with alpha-tocopherol
was synergistic and was not shared by beta-tocopherol, ascorbic acid and
probucol. Copyright 1998 Academic Press.
42. Cancer Epidemiol Biomarkers Prev. 1996 Oct;5(10):823-33.
cis-trans lycopene isomers, carotenoids, and retinol in the human prostate.
Clinton SK, Emenhiser C, Schwartz SJ, Bostwick DG, Williams AW, Moore
BJ, Erdman
JW Jr.
Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
02115-6084, USA.
An evaluation of the Health Professionals Follow-Up Study has detected
a lower
prostate cancer risk associated with the greater consumption of tomatoes
and
related food products. Tomatoes are the primary dietary source of lycopene,
a
non-provitamin A carotenoid with potent antioxidant activity. Our goal
was to
define the concentrations of lycopene, other carotenoids, and retinol
in paired
benign and malignant prostate tissue from 25 men, ages 53 to 74, undergoing
prostatectomy for localized prostate cancer. The concentrations of specific
carotenoids in the benign and malignant prostate tissue from the same
subject
are highly correlated. Lycopene and all-trans beta-carotene are the predominant
carotenoids observed, with means +/- SE of 0.80 +/- 0.08 nmol/g and 0.54
+/-
0.09, respectively. Lycopene concentrations range from 0 to 2.58 nmol/g,
and
all-trans beta-carotene concentrations range from 0.09 to 1.70 nmol/g.
The 9-cis
beta-carotene isomer, alpha-carotene, lutein, alpha-cryptoxanthin, zeaxanthin,
and beta-cryptoxanthin are consistently detectable in prostate tissue.
No
significant correlations between the concentration of lycopene and the
concentrations of any other carotenoid are observed. In contrast, strong
correlations between prostate beta-carotene and alpha-carotene are noted
(correlation coefficient, 0.88; P < 0.0001), as are correlations between
several
other carotenoid pairs, which reflects their similar dietary origins.
Mean
vitamin A concentration in the prostate is 1.52 nmol/g, with a range of
0.71 to
3.30 nmol/g. We further evaluated tomato-based food products, serum, and
prostate tissue for the presence of geometric lycopene isomers using
high-performance liquid chromatography with a polymeric C30 reversed phase
column. All-trans lycopene accounts for 79 to 91% and cis lycopene isomers
for 9
to 21% of total lycopene in tomatoes, tomato paste, and tomato soup. Lycopene
concentrations in the serum of men range between 0.60 and 1.9 nmol/ml,
with 27
to 42% all-trans lycopene and 58 to 73% cis-isomers distributed among
12 to 13
peaks, depending upon their chromatographic resolution. In striking contrast
with foods, all-trans lycopene accounts for only 12 to 21% and cis isomers
for
79 to 88% of total lycopene in benign or malignant prostate tissues. cis
Isomers
of lycopene within the prostate are distributed among 14 to 18 peaks.
We
conclude that a diverse array of carotenoids are found in the human prostate
with significant intra-individual variation. The presence of lycopene
in the
prostate at concentrations that are biologically active in laboratory
studies
supports the hypothesis that lycopene may have direct effects within the
prostate and contribute to the reduced prostate cancer risk associated
with the
reduced prostate cancer risk associated with the consumption of tomato-based
foods. The future identification and characterization of geometric lycopene
isomers may lead to the development of novel agents for chemoprevention
studies.
Skin
43. J Nutr. 2003 Jan;133(1):98-101.
Supplementation with beta-carotene or a similar amount of mixed carotenoids
protects humans from UV-induced erythema.
Heinrich U, Gartner C, Wiebusch M, Eichler O, Sies H, Tronnier H, Stahl
W.
Institut fur Experimentelle Dermatologie, Universitat Witten-Herdecke,
Germany.
Carotenoids are useful oral sun protectants, and supplementation with
high doses
of beta-carotene protects against UV-induced erythema formation. We compared
the
erythema-protective effect of beta-carotene (24 mg/d from an algal source)
to
that of 24 mg/d of a carotenoid mix consisting of the three main dietary
carotenoids, beta-carotene, lutein and lycopene (8 mg/d each). In a
placebo-controlled, parallel study design, volunteers with skin type II
(n = 12
in each group) received beta-carotene, the carotenoid mix or placebo for
12 wk.
Carotenoid levels in serum and skin (palm of the hand), as well as erythema
intensity before and 24 h after irradiation with a solar light simulator
were
measured at baseline and after 6 and 12 wk of treatment. Serum beta-carotene
concentration increased three- to fourfold (P < 0.001) in the beta-carotene
group, whereas in the mixed carotenoid group, the serum concentration
of each of
the three carotenoids increased one- to threefold (P < 0.001). No changes
occurred in the control group. The intake of either beta-carotene or a
mixture
of carotenoids similarly increased total carotenoids in skin from wk 0
to wk 12.
No changes in total carotenoids in skin occurred in the control group.
The
intensity of erythema 24 h after irradiation was diminished in both groups
that
received carotenoids and was significantly lower than baseline after 12
wk of
supplementation. Long-term supplementation for 12 wk with 24 mg/d of a
carotenoid mix supplying similar amounts of beta-carotene, lutein and
lycopene
ameliorates UV-induced erythema in humans; the effect is comparable to
daily
treatment with 24 mg of beta-carotene alone.
Oral cancers
44. J Nutr. 2002 Dec;132(12):3754-9.
Lycopene inhibits proliferation and enhances gap-junction communication
of KB-1
human oral tumor cells.
Livny O, Kaplan I, Reifen R, Polak-Charcon S, Madar Z, Schwartz B.
Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural,
Food and Environmental Quality Sciences, The Hebrew University of Jerusalem,
Rehovot 76100, Israel.
Cell-cell interaction via gap junctions is considered to be a key factor
in
tissue homeostasis, and its alteration is associated with the neoplastic
phenotype. Experimental and epidemiologic data suggest that carotenoids,
particularly lycopene and beta-carotene, can reduce the risk of certain
cancers.
The aim of this study was to assess whether lycopene and beta-carotene
interfere
at some stage with the carcinogenic processes in human cancer cells derived
from
the oral cavity. KB-1 cells, originating from a human oral cavity tumor,
were
incubated with different concentrations of lycopene or beta-carotene delivered
via the cell culture media from stock solutions in tetrahydrofuran. Lycopene
strongly and dose dependently inhibited proliferation of KB-1 human oral
tumor
cells. beta-Carotene was a far less effective growth inhibitor. Lycopene
(3 and
7 micro mol/L) significantly upregulated both the transcription (P <
0.005) and
the expression (P < 0.05) of connexin 43, a key protein in the formation
of
gap-junctional communication. beta-Carotene (3 micro mol/L) tended to
upregulate
connexin 43 expression (P = 0.07) and significantly affected transcription
of
connexin 43 at 7 micro mol/L (P < 0.05). Gap-junctional communication
measured
by scrape-loading dye transfer and electron microscopy showed that lycopene
enhanced gap-junctional communication between the cancer cells, whereas
beta-carotene was less effective in this regard. The pattern of cellular
uptake
and incorporation into cancer KB-1 cells differed significantly between
the
carotenoids. beta-Carotene was avidly and rapidly incorporated into KB-1
cells,
whereas lycopene uptake into the cells took place after longer incubation
periods and only at the highest concentrations. The results of the present
study
further support the hypothesis that carotenoids in general, and lycopene
in
particular, may be effective anticarcinogenic agents in oral carcinogenesis.
Cancer
45. Exp Biol Med (Maywood). 2002 Nov;227(10):860-3.
Tomatoes, lycopene intake, and digestive tract and female hormone-related
neoplasms.
La Vecchia C.
Istituto di Ricerche Farmacologiche Mario Negri, Via Eritrea 62, 20157
Milan,
Italy. garimoldi@marionegri.it
Tomato consumption showed a consistent inverse relation with the risk
of
digestive tract neoplasms in Italy in an integrated series of studies
conducted
in the 1980s. Another series of case-control studies was conducted between
1992
and 1999 in different areas of Italy. Cases were patients below age 80
with
incident, histologically confirmed cancer of the oral cavity and pharynx
(n =
754), esophagus (n = 304), colorectum (n = 1953), breast (n = 2529), and
ovary
(n = 1031). The comparison group involved, overall, over 5000 patients
below age
80 with acute, non-neoplastic, nonhormone-related diseases, unrelated
to
long-term diet modifications and admitted to the same network of hospitals.
Information was collected in hospital by trained interviewers using a
validated
food frequency questionnaire, including 78 foods or groups of foods, various
alcoholic beverage, and fat-intake pattern. The multivariate relative
risk (RR)
of oral, pharyngeal, and esophageal cancer decreased across subsequent
levels of
lycopene intake to reach 0.7 (95% confidence interval [CI] 0.4-1.0) for
oral and
pharyngeal, and 0.7 (95% CI 0.4-1.1) for esophageal cancer in the highest
quintile of intake. Both trends in risk were of borderline statistical
significance. With reference to colorectal, breast, and ovarian cancer,
although
no consistent association was observed for lycopene (RR = 1.0 for colorectal,
1.2 for breast, and 1.1 for ovary in the highest quintile), tomato intake
was
inversely and significantly related with colorectal cancer (RR = 0.8).
The
inverse relation between lycopene and upper digestive tract neoplasms
was not
explained by alcohol or tobacco, sociodemographic factors, or total energy
intake. The interpretation of such an inverse relation, however, remains
open to
discussion because it may be related to an effect of lycopene due to its
antioxidant effect and/or a potential role of lycopene in decreasing insulin
growth factor I, which is a promoter in the process of carcinogenesis.
46. Int J Vitam Nutr Res. 2002 Jul;72(4):237-50.
Serum antioxidants and subsequent mortality rates of all causes or cancer
among
rural Japanese inhabitants.
Ito Y, Suzuki K, Suzuki S, Sasaki R, Otani M, Aoki K.
Department of Public Health, Fujita Health University School of Health
Sciences,
Toyoake, Japan. yoshiito@fujita-hu.ac.jp
The purpose of this study was to investigate whether a relationship exists
between mortality rates and serum antioxidant levels among Japanese inhabitants.
The follow-up subjects, who participated in comprehensive health examinations,
consisted of 2444 inhabitants (949 males and 1495 females) of a rural
area in
Hokkaido, Japan. Between 1991 and December 2000, 146 subjects (94 males
and 52
females) died, with cancer accounting for 76 of these deaths (48 males
and 28
females). Serum samples at fasting were collected at entry into the study,
and
serum levels of beta- and alpha-carotenes, lycopene, beta-cryptoxanthin,
canthaxanthin, zeaxanthin/lutein, tocopherols, and retinol were measured
separately by high-performance liquid chromatography (HPLC). The statistical
analyses were conducted using the Cox proportional hazard model. Age-
and
gender-adjusted hazard ratios of the groups with high serum levels of
lycopene,
beta-carotene, zeaxanthin/lutein, and total carotenoids compared to those
with
low serum levels were 0.36 (95% C.I: 0.19-0.69), 0.53 (0.29-0.95), 0.73
(0.43-1.25), and 0.52 (0.30-0.92) for cancers of all sites, and 0.44 (95%
C.I:
0.28-0.69), 0.59 (0.39-0.90), 0.61 (0.40-0.93), and 0.50 (0.33-0.76) for
all
causes, respectively. Similar results were found after adjusting for gender,
age, smoking habits, alcohol consumption, and serum levels of total cholesterol
and glutamic pyruvic transaminase (GPT) activity. Moreover, after excluding
mortality within the first three years of follow-up, the hazard ratios
of
subjects with high serum levels of lycopene, total carotenes, and total
carotenoids were significantly and inversely associated with subsequent
mortality from all causes and cancers of all sites after adjusting for
gender,
age, and serum levels of total cholesterol, alpha-tocopherol, and retinol.
These
results suggest that high serum levels of antioxidants, such as lycopene,
beta-carotene and zeaxanthin/lutein, play roles in preventing death from
cancer
and from all causes. However, high serum levels of tocopherols and retinol
did
not demonstrate clear associations with either low mortality rates from
all
causes or cancer of all sites.
47. Nutr Cancer. 2000;38(1):23-9.
Vegetables, fruits, related dietary antioxidants, and risk of squamous
cell
carcinoma of the esophagus: a case-control study in Uruguay.
De Stefani E, Brennan P, Boffetta P, Ronco AL, Mendilaharsu M, Deneo-Pellegrini
H.
Registro Nacional de Cancer, Montevideo, Uruguay.
In 1998-1999, a case-control study on esophageal cancer was conducted
in
Uruguay. For this purpose, 111 cases with squamous cell carcinoma of the
esophagus and 444 controls with conditions unrelated to tobacco smoking,
alcohol
drinking, or recent changes in the diet were frequency matched on age,
gender,
residence, and urban/rural status. Vegetables and, more markedly, fruits
were
associated with strong reductions in risk. On the other hand, 12 of 15
dietary
antioxidants displayed significant inverse associations with esophageal
cancer
risk. The strongest effect was observed for high intake of beta-cryptoxanthin
(odds ratio = 0.16, 95% confidence interval = 0.08-0.36). Also, alpha-carotene,
lycopene, and beta-sitosterol were associated with significant reductions
in
risk. Most antioxidants lost their effect when they were further adjusted
for a
term for all vegetables and fruits. beta-Carotene showed an increased
risk with
high intakes. On the other hand, vegetables and fruits remained as significant
variables after adjustment for each antioxidant, suggesting that other
substances or other mechanisms could explain this effect.
48. Oral Oncol. 2000 Jan;36(1):47-53.
Tomatoes, tomato-rich foods, lycopene and cancer of the upper aerodigestive
tract: a case-control in Uruguay.
De Stefani E, Oreggia F, Boffetta P, Deneo-Pellegrini H, Ronco A, Mendilaharsu
M.
Registro Nacional de Cancer, Montevideo, Uruguay.
In order to study the relationship between tomatoes, tomato products,
lycopene
and cancers of the upper aerodigestive tract (UADC; oral cavity, pharynx,
larynx, esophagus) a case-control study was carried out in Uruguay, in
the time
period 1996-98. Two-hundred and thirty eight cases and 491 hospitalized
controls
were frequency matched on age, sex, residence and urban/rural status.
Both
series were submitted to a detailed questionnaire, including tobacco smoking,
alcohol drinking and queries on 64 food items. These data were analyzed
by
unconditional logistic regression, after adjusting by total energy intake.
Tomato intake was associated with a reduction in risk of 0.30 (95% confidence
interval [CI], 0.18-0.51), whereas tomato sauce-rich foods displayed a
protective effect of 0.57 (95% CI, 0.33-0.96 for the highest quartile
of
intake). The food group composed of raw tomato and tomato-rich foods showed
a
strong inverse association with UADC (odds ratio [OR], 0.23; 95% CI, 0.13-0.39
for the highest quartile of intake). Lycopene was also strongly associated
with
a reduced risk of 0.22 (95% CI, 0.13-0.37). Adjustment of tomato intake
for
several phytochemicals explained almost completely its protective effect,
which
disappears in this model. Finally, the joint effect of lycopene and total
phytosterols was associated with a significant reduction in risk (OR,
0.11; 95%
CI, 0.05-0.23).
49. Nutr Cancer. 1999;33(1):105-12.
Lycopene and 1,25-dihydroxyvitamin D3 cooperate in the inhibition of
cell cycle
progression and induction of differentiation in HL-60 leukemic cells.
Amir H, Karas M, Giat J, Danilenko M, Levy R, Yermiahu T, Levy J, Sharoni
Y.
Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion
University of the Negev, Beer-Sheva, Israel.
Lycopene, the major tomato carotenoid, has been found to inhibit proliferation
of several types of cancer cells, including those of breast, lung, and
endometrium. By extending the work to the HL-60 promyelocytic leukemia
cell
line, we aimed to evaluate some mechanistic aspects of this effect.
Particularly, the possibility was examined that the antiproliferative
action of
the carotenoid is associated with induction of cell differentiation. Lycopene
treatment resulted in a concentration-dependent reduction in HL-60 cell
growth
as measured by [3H]thymidine incorporation and cell counting. This effect
was
accompanied by inhibition of cell cycle progression in the G0/G1 phase
as
measured by flow cytometry. Lycopene alone induced cell differentiation
as
measured by phorbol ester-dependent reduction of nitro blue tetrazolium
and
expression of the cell surface antigen CD14. Results of several recent
intervention studies with beta-carotene, which have revealed no beneficial
effects of this carotenoid, suggest that a single dietary component cannot
explain the anticancer effect of diets rich in vegetables and fruits.
Thus
another goal of our study was to examine whether lycopene has the ability
to
synergize with other natural anticancer compounds, such as 1,25-dihydroxyvitamin
D3, which when used alone are therapeutically active only at high and
toxic
concentrations. The combination of low concentrations of lycopene with
1,25-dihydroxyvitamin D3 exhibited a synergistic effect on cell proliferation
and differentiation and an additive effect on |