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Pycnogenol: 35 Research Abstracts

1. J Sex Marital Ther. 2003 May-Jun;29(3):207-13.

Treatment of erectile dysfunction with pycnogenol and L-arginine.

Stanislavov R, Nikolova V.

Seminological Laboratory SBALAG, Maichin Dom, Sofia, Bulgaria.

Penile erection requires the relaxation of the cavernous smooth muscle, which is triggered by nitric oxide (NO). We investigated the possibility of overcoming erectile dysfunction (ED) by increasing the amounts of endogenous NO. For this purpose, we orally administered Pycnogenol, because it is known to increase production of NO by nitric oxide syntase together with L-arginine as substrate for this enzyme. The study included 40 men, aged 25-45 years, without confirmed organic erectile dysfunction. Throughout the 3-month trial period, patients received 3 ampoules Sargenor a day, a drinkable solution of the dipeptide arginyl aspartate (equivalent to 1.7 g L-arginine per day). During the second month, patients were additionally supplemented with 40 mg Pycnogenol two times per day; during the third month, the daily dosage was increased to three 40-mg Pycnogenol tablets. We obtained a sexual function questionnaire and a sexual activity diary from each patient. After 1 month of treatment with L-arginine, a statistically nonsignificant number of 2 patients (5%) experienced a normal erection. Treatment with a combination of L-arginine and Pycnogenol for the following month increased the number of men with restored sexual ability to 80%. Finally, after the third month of treatment, 92.5% of the men experienced a normal erection. We conclude that oral administration of L-arginine in combination with Pycnogenol causes a significant improvement in sexual function in men with ED without any side effects.

2. Phytother Res. 2003 Jun;17(6):671-4.

Pycnogenol prevents haemolytic injury in G6PD deficient human erythrocytes.

Sharma SC, Sharma S, Gulati OP.

Department of Pharmacology and Therapeutics, Trinity College, Dublin-2 Ireland.

Glucose6 phosphate dehydrogenase (G6PD) deficiency is the most common X-linked disorder of human erythrocytes where cells have inadequate capacity to destroy peroxides and high susceptibility towards haemolytic changes. Pycnogenol is a proprietary dry extract of the French Maritime pine (Pinus pinaster) bark with high ability to scavenge free radicals. In the present study we have investigated if Pycnogenol can protect G6PD deficient erythrocytes against haemolytic cell damage. Venous blood samples were obtained from six subject of Mediterranean origin with known G6PD deficiency which was also confirmed with standard techniques. Erythrocyte haemolysis in the presence and absence of Pycnogenol was induced either with tert-butylhydroperoxide (t-BHP) or quinine and the haemoglobin release in the supernatant was determined by recording the optical density at 540 nm in a Shimadzu spectrophotometer. Our results have shown that Pycnogenol has protective action against a Xenobiotic chemical induced haemolysis in G6PD deficient human erythrocytes. Copyright 2003 John Wiley & Sons, Ltd.

3. J Biochem Mol Toxicol. 2003;17(3):193-9.

Effects of pycnogenol treatment on oxidative stress in streptozotocin-induced diabetic rats.

Maritim A, Dene BA, Sanders RA, Watkins JB 3rd.

Moi University Faculty of Health Sciences, Eldoret, Kenya.

Free radicals and oxidative stress have been implicated in the etiology of diabetes and its complications. This in vivo study has examined whether subacute administration of pycnogenol, a French pine bark extract containing procyanidins that have strong antioxidant potential, alters biomarkers of oxidative stress in normal and diabetic rats. Diabetes was induced in female Sprague-Dawley rats by a single injection of streptozotocin (90 mg/kg body weight, ip), resulting (after 30 days) in subnormal body weight, increased serum glucose concentrations, and an increase in liver weight, liver/body weight ratios, total and glycated hemoglobin, and serum aspartate aminotransferase activity. Normal and diabetic rats were treated with pycnogenol (10 mg/kg body weight/day, ip) for 14 days. Pycnogenol treatment significantly reduced blood glucose concentrations in diabetic rats. Biochemical markers for oxidative stress were assessed in the liver, kidney, and heart. Elevated hepatic catalase activity in diabetic rats was restored to normal levels after pycnogenol treatment. Additionally, diabetic rats treated with pycnogenol had significantly elevated levels of reduced glutathione and glutathione redox enzyme activities. The results demonstrate that pycnogenol alters intracellular antioxidant defense mechanisms in streptozotocin-induced diabetic rats. Copyright 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:193-199, 2003; Published online in Wiley InterScience ( DOI 10.1002/jbt.10078

4. J Med Food. 2001 Winter;4(4):201-209.

Pycnogenol((R)) in the Management of Asthma.

Hosseini S, Pishnamazi S, Sadrzadeh SM, Farid F, Farid R, Watson RR.

College of Public Health and School of Medicine, The University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724.

Asthma is characterized as a chronic inflammatory process. Pycnogenol((R)), a bioflavonoid mixture extracted from Pinus maritima, is known to scavenge free radicals while possessing antioxidant and antiinflammatory properties. The objective of this study was to evaluate the efficiency of this agent in a randomized, double-blinded, placebo-controlled, crossover study in patients with varying asthma severity. Twenty-six patients who fulfilled the American Thoracic Society criteria for asthma were enrolled in the study. Medical history, physical examination, blood sample analyses, and spirometric values were obtained at baseline, 4 weeks, and 8 weeks. The patients were randomly assigned to receive either 1 mg/lb/day (maximum 200 mg/day) Pycnogenol or placebo for the first period of 4 weeks and then crossed over to the alternate regimen for the next 4 weeks. No adverse effects were observed related to the study drug. Within the contingent of 22 patients who completed the study, almost all responded favorably to Pycnogenol in contrast to placebo. Pycnogenol treatment also significantly reduced serum leukotrienes compared with placebo. The results of this pilot study indicate that Pycnogenol may be a valuable nutraceutical in the management of chronic asthma. We recommend that further clinical trials be conducted in larger groups of asthmatics to establish its efficacy.

5. Phytother Res. 2003 Jan;17(1):66-9.

Pycnogenol inhibits the release of histamine from mast cells.

Sharma SC, Sharma S, Gulati OP.

Department of Pharmacology and Therapeutics, Trinity College, Dublin-2, Ireland.

Oxygen derived free radicals are now increasingly regarded as a primary force of tissue destruction and also have the ability to release histamine from mast cells. Pycnogenol is an extract of the bark of French maritime pine (Pinus pinaster) containing bioflavonoids with a potent ability to scavenge free radicals. Therefore Pycnogenol was investigated for inhibition of histamine release from rat peritoneal mast cells. In addition, its effects were compared with sodium cromoglycate, a known inhibitor of histamine release from the mast cell. Rat peritoneal mast cells were isolated and purified by differential centrifugation and cells pooled from 3-4 animals were suspended at approximately 10(6) cells/mL buffered salt solution. Histamine release was induced by compound 48/80 or the calcium ionophore A-23187 and estimated from supernatant following extraction and by fluorimetric methods. Pycnogenol produced a concentration dependent inhibition of histamine release induced by the two secretagogues. Its inhibitory effect on mast cell histamine release was favourably comparable to sodium cromoglycate. Copyright -Copyright 2003 John Wiley & Sons, Ltd

6. J Am Diet Assoc. 2003 Jan;103(1):67-72.

Pycnogenol does not impact the antioxidant or vitamin C status of healthy young adults.

Silliman K, Parry J, Kirk LL, Prior RL.

Department of Biological Sciences (Program in Nutrition and Food Science),
California State University, Chico 95929, USA.

OBJECTIVE: The objectives of this study were to determine if Pycnogenol (PYC), a water-processed extract made from the bark of Pinus maritima, interacts with vitamin C to increase its concentration and to increase total antioxidant capacity of serum and urine. DESIGN: The study design was a nonrandom intervention. SUBJECTS: Subjects (N=27; 15 women, 12 men) were aged 19 to 42 years. INTERVENTION: Subjects consumed a placebo twice daily with meals for the first 2 weeks (baseline) and PYC (200 mg/day) for the second 2 weeks. Main outcome measures On days 15 and 29, subjects had a fasting blood sample collected and then consumed a daily dose of placebo or PYC with a 310-calorie beverage. One hour later a second blood sample was collected. Blood samples were analyzed for vitamin C and total antioxidant capacity using the ORAC (oxygen radical absorbance capacity) assay. Twenty-four-hour urine samples were collected on days 14-15 and 28-29 and analyzed for total phenolics, FRAP (ferric reducing antioxidant potential), and ORAC. Statistical analyses Paired t tests were used to test the impact of PYC on the outcome variables. A univariate ANOVA was used to determine the influence of gender. Pearson's correlation analysis was used to explore the relationships between dietary factors and outcome measures. RESULTS: There was no apparent increase in fasting vitamin C concentration (P=.18) 2 weeks after supplementing the diet with PYC. Fasting ORAC values actually declined (P=.005). One hour after the ingestion of a daily dose of placebo or PYC, the total antioxidant capacity of serum increased by 15% to 19%, but the increase after ingesting PYC was not significantly (P=.80) more than after placebo. Antioxidant results from 24-hour urine samples were similar. APPLICATIONS/CONCLUSIONS: The present findings fail to support the vitamin C or antioxidant claims made for PYC. PYC does not impact the antioxidant or vitamin C status of healthy young adults.

7. Int Ophthalmol. 2001;24(3):161-71.

Pycnogenol for diabetic retinopathy. A review.

Schonlau F, Rohdewald P.

Institute of Pharmaceutical Chemistry, Westfalische Wilhelms Universitat Munster, Germany.

Diabetic retinopathy represents a serious health threat to a rapidly growing number of patients with diabetes mellitus. The retinal microangiopathy is characterised by vascular lesions with exudate deposits and haemorrhages causing vision loss. Pycnogenol, a standardised extract of the bark of the French maritime pine (Pinus pinaster), is known to increase capillary resistance. Pycnogenol has been tested for treatment and prevention of retinopathy in five clinical trials with a total number of 1289 patients since the late 1960's. All but one of these studies have been reported in French and German and, today, are of limited accessibility, giving the impetus for reviewing them in detail in this article. There were two open case studies and two double blind studies (one controlled against calcium dobesilate and another against placebo) and, finally, one multi-center field study with 1169 diabetics. All of these studies unequivocally showed that Pycnogenol retains progression of retinopathy and partly recovers visual acuity. Treatment efficacy of Pycnogenol was at least as good as that of calcium dobesilate. Pycnogenol was shown to improve capillary resistance and reduce leakages into the retina. Tolerance was generally very good and side effects were rare, mostly referring to gastric discomfort. In conclusion, treatment with Pycnogenol had a favourable outcome in the majority of the patients with diabetic retinopathy.

8. Phytother Res. 2002 Sep;16(6):567-71.

Treatment of melasma with Pycnogenol.

Ni Z, Mu Y, Gulati O.

Beijing PHT Nutriment Science Technology Development Co. Ltd, Xiyuan Hospital of China Academy of Traditional Chinese Medicine, Institute of Food Safety Control and Inspection, Ministry of Public Health, Beijing, P R China.

Melasma (or chloasma) is a common disorder of cutaneous hyperpigmentation predominantly affecting sun-exposed areas in women. The pathogenesis of melasma is not fully understood and treatments are frequently disappointing and often associated with side effects.Pycnogenol is a standardized extract of the bark of the French maritime pine (Pinus pinaster), a well-known, potent antioxidant. Studies in vitro show that Pycnogenol is several times more powerful than vitamin E and vitamin C. In addition, it recycles vitamin C, regenerates vitamin E and increases the endogenous antioxidant enzyme system. Pycnogenol protects against ultraviolet (UV) radiation. Therefore its efficacy in the treatment of melasma was investigated.Thirty women with melasma completed a 30-day clinical trial in which they took one 25 mg tablet of Pycnogenol with meals three times daily, i.e. 75 mg Pycnogenol per day. These patients were evaluated clinically by parameters such as the melasma area index, pigmentary intensity index and by routine blood and urine tests.After a 30-day treatment, the average melasma area of the patients decreased by 25.86 +/- 20.39 mm(2) (p < 0.001) and the average pigmentary intensity decreased by 0.47 +/- 0.51 unit (p < 0.001). The general effective rate was 80%. No side effect was observed. The results of the blood and urine test parameters at baseline and at day 30 were within the normal range. Moreover, several other associated symptoms such as fatigue, constipation, pains in the body and anxiety were also improved.To conclude, Pycnogenol was shown to be therapeutically effective and safe in patients suffering from melasma. Copyright 2002 John Wiley & Sons, Ltd.

9. Phytomedicine. 2002 Jul;9(5):414-8.

Effect of PYCNOGENOL on the toxicity of heart, bone marrow and immune organs as induced by antitumor drugs.

Feng WH, Wei HL, Liu GT.

Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union of Medical College, Beijing, People's Republic of China.

PYCNOGENOL is a mixture of water-soluble bioflavonoids extracted from the bark of pine trees growing in the southwest coastal region of France. In the present paper the effects of PYCNOGENOL (Pyc) on the toxicity of bone marrow, heart and immune organs induced by anticancer drugs were investigated, in mice. The following results were obtained: 1. Pyc at the orally-administered dose of 200 and 150 mg/kg body wt. markedly prevented the elevation of serum creatine phosphokinase (CPK) activity and the decrease of heart rate in mice treated with doxorubicin (Dox); 2. Pyc at 100 and 150 mg/kg body wt. significantly antagonized the inhibition of DNA synthesis in thymus induced by subcutaneous injection of cyclophosphamide (Cyc); 3. Pyc at 150 and 200 mg/kg body wt. markedly induced increase of erythrocytes and hemoglobin, but had no effect on leukopenia, in Cyc-treated mice; and 4. Pyc has no antagonizing effect on the anticancer activity of Dox and Cyc. All the results suggest that Pyc possesses a protective effect on the cardiotoxicity of Dox and the inhibition of thymus DNA synthesis induced by Cyc in mice.

10. Phytomedicine. 2002 Jul;9(5):410-3.

PYCNOGENOL chewing gum minimizes gingival bleeding and plaque formation.

Kimbrough C, Chun M, dela Roca G, Lau BH.

School of Dentistry, Loma Linda University, California, USA.

PYCNOGENOL is an antioxidant phytochemical shown to have antiinflammatory activity in both the in vitro and in vivo models. This study compared the effects of chewing gums with and without PYCNOGENOL on gingival bleeding and plaque formation in 40 human subjects. In this double-blind study, subjects were assigned randomly to receive either control gums without PYCNOGENOL or experimental gums containng 5 mg PYCNOGENOL. Subjects used chewing gums for 14 days. Gingival bleeding and plaque scores were taken before and after the experiment. PYCNOGENOL chewing gums significantly reduced gingival bleeding, while no changes were noted in bleeding indexes in control subjects who used regular chewing gums. Subjects using regular control gums had significant increases of dental plaque accumulation during the two-week period. No increases in plaque accumulation were noted in subjects using PYCNOGENOL chewing gums. The data of this study suggest that the use of Pycnogenol chewing gums can minimize gingival bleeding and plaque accumulation.

11. J Atten Disord. 2002 Sep;6(2):49-60.

An experimental comparison of Pycnogenol and methylphenidate in adults with Attention-Deficit/Hyperactivity Disorder (ADHD).

Tenenbaum S, Paull JC, Sparrow EP, Dodd DK, Green L.

The Attention Deficit Center in St. Louis 63141, MO.

Twenty-four adults (24 to 53 years old) with Attention-Deficit/Hyperactivity Disorder (ADHD), Combined Type, were studied in a double-blind, placebo-controlled, crossover study of Pycnogenol and methylphenidate. Pycnogenol is an antioxidant derived from the bark of the French maritime pine tree. Methylphenidate is a standard pharmaceutical intervention for ADHD. Anecdotal reports suggest that Pycnogenol improves concentration in adults with ADHD without adverse side effects. Participants received Pycnogenol, methylphenidate, and placebo, each for three weeks, in a randomized and counterbalanced order. Although ADHD symptoms improved during treatment, neither methylphenidate nor Pycnogenol outperformed the placebo control, as measured by self-report rating scales, rating scales completed by the individual's significant other, and a computerized continuous performance test. The conservative dosage levels and relatively brief length of treatment may have contributed to the absence of significant differences among treatment conditions. Implications for future research are noted.

12. Growth Horm IGF Res. 2002 Feb;12(1):34-40.

Kyolic and Pycnogenol increase human growth hormone secretion in
genetically-engineered keratinocytes.

Buz'Zard AR, Peng Q, Lau BH.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.

The amount of human growth hormone (HGH) decreases significantly after the age of 30. This decrease has been implicated as one of the major causes in the signs of aging, such as thinning of the skin and bones, a decrease in lean muscle mass and an increase in adipose tissue. Supplementing the body's dwindling supply with recombinant human growth hormone (rHGH) has been shown to reverse the signs and symptoms of aging. However, drawbacks in rHGH replacement therapy include prohibitively high cost, the need for repeated injection and side effects such as carpel tunnel syndrome, gynecomastia and insulin resistance. The purpose of this study was to establish an in vitro model using genetically-engineered keratinocytes to screen natural compounds for the ability to stimulate HGH secretion. We now report that a combination of equal amounts of L-arginine and L-lysine, aged garlic extract (Kyolic), S-allyl cysteine and Pycnogenol significantly increased secretion of HGH in this in vitro model. The data indicate that this in vitro model may be used to screen for other secretagogues.

13. Brain Res Mol Brain Res. 2002 Jul 15;104(1):55-65.

Pycnogenol protects neurons from amyloid-beta peptide-induced apoptosis.

Peng QL, Buz'Zard AR, Lau BH.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.

Neuronal apoptosis is one of the pathological features of Alzheimer's disease (AD). Morphological pathology reveals that neuronal apoptosis is associated with senile plaques containing amyloid-beta peptide (Abeta) in AD brains. Reactive oxygen species (ROS) has been proposed to be involved in the apoptotic mechanism of Abeta-mediated neurotoxicity. In the present study, using a rat pheochromocytoma (PC12) cell line, we investigated the effect of Pycnogenol (PYC), a potent antioxidant and ROS scavenger, on Abeta(25-35)-induced apoptosis and ROS generation. We used vitamin E, a known antioxidant agent, to verify the effect of PYC. Abeta(25-35)-induced apoptosis in PC12 cells was demonstrated by: (1) a dose-dependent loss of cell viability; (2) a time- and dose-dependent increase in the apoptotic cells; (3) an induction of DNA fragmentation; and (4) an increase in caspase-3 activity and cleavage of poly (ADP-ribose) polymerase (PARP). Our data showed that a significant increase in ROS formation preceded apoptotic events after PC12 cells were exposed to Abeta(25-35). We further found that PYC not only suppressed the generation of ROS but also attenuated caspase-3 activation, DNA fragmentation, PARP cleavage, and eventually protected against Abeta-induced apoptosis. Vitamin E also suppressed cell death and caspase-3 activation induced by Abeta(25-35). Taken together, these results suggest that ROS may be involved in Abeta-induced apoptosis in PC12 cells. They further suggest that PYC can reduce apoptosis, possibly by decreasing free radical generation in PC12 cells.

14. Int J Clin Pharmacol Ther. 2002 Apr;40(4):158-68.

A review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology.

Rohdewald P.

Institute Pharmaceutical Chemistry, Westfalische Wilhelms-Universitat Munster, Germany.

OBJECTIVES: An increasing body of evidence indicates that Pycnogenol (PYC), a standardized extract of French maritime pine bark, has favorable pharmacological properties. This is a review of studies with both PYC and components of the preparation, that have helped to elucidate target sites and possible mechanisms for activity in men. METHODS: Studies appearing in peer reviewed literature, as well as results presented at international meetings not yet available as published papers, are included in this review. Additional data from published sources in German and French languages that are not widely available are also included. RESULTS: Chemical identification studies showed that PYC is primarily composed of procyanidins and phenolic acids. Procyanidins are biopolymers of catechin and epicatechin subunits which are recognized as important constituents in human nutrition. PYC contains a wide variety of procyanidins that range from the monomeric catechin and taxifolin to oligomers with 7 or more flavonoid subunits. The phenolic acids are derivatives of benzoic and cinnamic acids. The ferulic acid and taxifolin components are rapidly absorbed and excreted as glucuronides or sulphates in men, whereas procyanidins are absorbed slowly and metabolized to valerolactones which are excreted as glucuronides. PYC has low acute and chronic toxicity with mild unwanted effects occurring in a small percentage of patients following oral administration. Clinical studies indicate that PYC is effective in the treatment of chronic venous insufficiency and retinal micro-hemorrhages. PYC protects against oxidative stress in several cell systems by doubling the intracellular synthesis of anti-oxidative enzymes and by acting as a potent scavenger of free radicals. Other anti-oxidant effects involve a role in the regeneration and protection of vitamin C and E. Anti-inflammatory activity has been demonstrated in vitro and in vivo in animals. Protection against UV-radiation-induced erythema was found in a clinical study following oral intake of PYC. In asthma patients symptom scores and circulating leukotrienes are reduced and lung function is improved. Immunomodulation has been observed in both animal models as well as in patients with Lupus erythematosus. PYC antagonizes the vasoconstriction caused by epinephrine and norepinephrine by increasing the activity of endothelial nitric oxide synthase. Dilation of the small blood vessels has been observed in patients with cardiovascular disease, whereas in smokers, PYC prevents smoking-induced platelet aggregation and reduces the concentration of thromboxane. The ability to inhibit angiotensin-converting enzyme is associated with a mild antihypertensive effect. PYC relieves premenstrual symptoms, including abdominal pain and this action may be associated with the spasmolytic action of some phenolic acids. An improvement in cognitive function has been observed in controlled animal experiments and these findings support anecdotal reports of improvement in ADHD patients taking PYC supplements. CONCLUSIONS: There is much evidence showing that PYC has beneficial effects on physiological functions. Results from ongoing clinical research are required to confirm and extend previous observations.

15. Phytother Res. 2002 Mar;16 Suppl 1:S1-5.

Comparative study of Venostasin and Pycnogenol in chronic venous insufficiency.

Koch R.

Wolfsschlucht 6a, 34117 Kassel, Germany.

The aim of this study was to compare the efficacy of Venostasin (horse chestnut seed extract) and Pycnogenol (French maritime pine bark extract) in the treatment of chronic venous insufficiency (CVI). In an open, controlled comparative study 40 patients with diagnosed CVI were treated either with 600 mg chestnut seed extract per day or 360 mg Pycnogenol per day over a period of 4 weeks. The following parameters were investigated before the start of treatment and after 2 and 4 weeks of treatment: circumference of the lower legs and rating of subjective symptoms (scores) of pain, cramps, night-time swelling, feeling of "heaviness", and reddening of the skin. In addition, blood levels of cholesterol LDL and HDL were determined before and at the end of treatment. Pycnogenol significantly reduced the circumference of the lower limbs and significantly improved subjective symptoms. Furthermore, Pycnogenol significantly decreased cholesterol and LDL values in the blood, whereas HDL remained unaffected. Venostasin only moderately but not significantly, reduced the circumference of the lower limbs and marginally improved symptoms. Venostasin had no influence on the determined lipid values. Both medications were equally well tolerated. In conclusion, Pycnogenol was found to be more efficacious than Venostasin for the treatment of CVI. Copyright 2002 John Wiley & Sons, Ltd.

16. Phytother Res. 2001 Dec;15(8):698-704.

Pycnogenol efficacy in the treatment of systemic lupus erythematosus patients.

Stefanescu M, Matache C, Onu A, Tanaseanu S, Dragomir C, Constantinescu I, Schonlau F, Rohdewald P, Szegli G.

Department of Immunology, Cantacuzino Institute, Splaiul Independentei 103,
Bucharest, Romania.

A pilot study was performed to evaluate the efficacy of Pycnogenol treatment in systemic lupus erythematosus (SLE) patients. Eleven SLE patients were treated with first line medication according to disease activity and in addition, six of them received Pycnogenol and five a placebo. The SLE disease activity index (SLEDAI), serum anti-dsDNA antibodies, fibrinogen, C-reactive protein levels, erythrocyte sedimentation rate, production of reactive oxygen species (ROS) by neutrophils, spontaneous apoptosis and p56(lck) specific activity in peripheral blood lymphocytes were evaluated. Pycnogenol treatment determined a significant reduction of ROS production, apoptosis, p56(lck) specific activity and erythrocyte sedimentation rate. In addition, the decrease of SLEDAI was significant in the Pycnogenol treated group compared with the placebo group (p = 0.018). The results obtained suggest that Pycnogenol could be useful for second line therapy to reduce the inflammatory feature of SLE. Copyright 2001 John WIley & Sons, Ltd.

17. Phytother Res. 2001 May;15(3):219-23.

Treatment of vascular retinopathies with Pycnogenol.

Spadea L, Balestrazzi E.

Dipartimento di Discipline Chirurgiche, Cattedra di Clinica Oculistica, Facolta di Medicina e Chirurgia, Via Vetoio, Coppito 2, L'Aquila, Italy.

The aim of our study was to investigate the effects of Pycnogenol on the progression of diabetic retinopathy and other vascular retinal disorders. The study consisted of a double-blind phase in which 20 patients were recruited and randomly treated with placebo or Pycnogenol (50 mg x 3/day for 2 months) and an open phase in which another 20 patients were treated with Pycnogenol at the same dose schedule. In total, 40 patients with diabetes, atherosclerosis and other vascular diseases involving the retina were enrolled; 30 of them were treated with Pycnogenol and 10 with placebo. The results demonstrated a beneficial effect of Pycnogenol on the progression of retinopathy. Without any treatment (placebo) the retinopathy progressively worsened during the trial and the visual acuity significantly decreased; on the contrary, the Pycnogenol-treated patients showed no deterioration of retinal function and a significant recovery of visual acuity was also obtained. The fluorangiography showed an improvement of retinal vascularization and a reduced endothelial permeability and leakage in the Pycnogenol, but not in the placebo-treated, patients. The ophthalmoscopy and the electroretinogram (ERG) also confirmed the beneficial effects of Pycnogenol. The mechanism of action of Pycnogenol may be related to its free radical (FR) scavenging, anti-inflammatory and capillary protective activities. It has been suggested that Pycnogenol may bind to the blood vessel wall proteins and mucopolysaccharides and produce a capillary 'sealing' effect, leading to a reduced capillary permeability and oedema formation. Copyright 2001 John Wiley & Sons, Ltd.

18. Free Radic Biol Med. 2000 Jan 15;28(2):219-27.

Pine bark extract pycnogenol downregulates IFN-gamma-induced adhesion of T cells to human keratinocytes by inhibiting inducible ICAM-1 expression.

Bito T, Roy S, Sen CK, Packer L.

Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.

Expression of intercellular adhesion molecule-1 (ICAM-1) is necessary for leukocyte/keratinocyte interactions. Upregulation of ICAM-1 expression in keratinocytes has been observed in several inflammatory dermatoses, such as psoriasis, atopic dermatitis, and lupus erythematosus. Inflammatory cytokines, such as interferon-gamma (IFN-gamma), upregulate ICAM-1 expression in keratinocytes. Because of potent antioxidant and anti-inflammatory properties of the French maritime pine bark extract, Pycnogenol (Horphag Research, Geneva, Switzerland), its effects were investigated on the interaction of T cells with keratinocytes after activation with IFN-gamma and the molecular mechanisms involved in such interactions. Studies were performed using a human keratinocyte cell line, HaCaT. Cell adhesion in the presence of IFN-gamma was studied using a coculture assay. Treatment of HaCaT cells with 20 U/ml IFN-gamma for 24 h markedly induced adherence of Jurkat T cells to HaCaT cells. PYC pretreatment (50 microg/ml, 12 h) significantly inhibited IFN-gamma induced adherence of T cells to HaCaT cells (p < .01). ICAM-1 plays a major role in the IFN-gamma-induced adherence of T cells to keratinocytes. Thus, the effect of PYC on IFN-gamma-induced ICAM-1 expression was investigated as well. Pretreatment of HaCaT cells with PYC significantly inhibited IFN-gamma-induced expression of ICAM-1 expression in HaCaT cells. The downregulation of inducible ICAM-1 expression by PYC was both dose and time dependent. A 50 microg/ml dose of PYC and a 12 h pretreatment time (i.e., before activation with IFN-gamma) provided maximal (approximately 70%) inhibition of inducible ICAM-1 expression in HaCaT cells. Gamma-activated sequence present on the ICAM-1 gene confers IFN-gamma responsiveness in selected cells of epithelial origin (e.g., keratinocytes) that are known to express ICAM-1 on activation with IFN-gamma. Gel-shift assays revealed that PYC inhibits IFN-gamma-mediated activation of Stat1, thus suggesting a transcriptional regulation of inducible ICAM-1 expression by PYC. These results indicate the therapeutic potential of PYC in patients with inflammatory skin disorders.

19. J Agric Food Chem. 2000 Nov;48(11):5630-9.

Enzyme inhibition and protein-binding action of the procyanidin-rich french maritime pine bark extract, pycnogenol: effect on xanthine oxidase.

Moini H, Guo Q, Packer L.

Department of Molecular and Cell Biology, 251 Life Sciences Addition, University of California at Berkeley, Berkeley, California 94720-3200, USA.

Pycnogenol, an extract from French maritime pine bark (PBE), is a complex mixture of bioflavonoids with reported protective effects against disease. PBE is an effective scavenger of reactive oxygen species, and its main constituents are procyanidins of various chain lengths. To find out the biochemical basis of action of PBE on enzyme activity, involvement of its redox activity and direct binding to the enzyme in its subsequent action on enzyme activity have been investigated. PBE dose-dependently inhibited the activities of xanthine oxidase, xanthine dehydrogenase, horseradish peroxidase, and lipoxygenase, but it did not affect the activities of glucose oxidase, ascorbate oxidase, or elastase. To characterize the mechanism of PBE action, studies were focused on xanthine oxidase and glucose oxidase. Under non-denaturing conditions, PBE changed the electrophoretic mobility of xanthine oxidase but not of glucose oxidase. Gel filtration chromatography confirmed higher molecular weight complexes of xanthine oxidase and xanthine dehydrogenase in the presence of PBE. It was found that hydrophobic bonding might be the dominant mode of interaction between PBE and xanthine oxidase. The importance of the binding in the effect of PBE on enzyme activity was supported by the observation that PBE binds to and inhibits catalase, but not superoxide dismutase. However, no correlation was found between superoxide/hydroxyl radical scavenging activity and the inhibitory effect on xanthine oxidase activity of PBE, various purified flavonoids, or other complex mixtures of bioflavonoids. The results indicate that PBE selectively inhibits xanthine oxidase through binding to the enzyme rather than by the redox activity.

20. Phytomedicine. 2000 Oct;7(5):383-8.

PYCNOGENOL in chronic venous insufficiency.

Petrassi C, Mastromarino A, Spartera C.

Cattedra e Scuola di Specializzazione in Chirurgia Vascolare, Dipartimento di Scienze Chirurgiche, Universita degli Studi di L'Aquila, Italy.

The aim of out study was to investigate the efficacy of Pycnogenol - a French maritime pine bark extract - in the treatment of chronic venous insufficiency (CVI). The study consisted of a double-blind phase - in which 20 patients were recruited and randomly treated with placebo or Pycnogenol (100 mg 2 3/day for 2 months) - and an open phase - in which other 20 patients were treated with Pycnogenol at the same dose schedule. In total, 40 patients were enrolled; 30 of them were treated with Pycnogenol and 10 with placebo. Pycnogenol significantly improved the legs' heaviness and subcutaneous edema; the venous pressure was also significantly reduced by the Pycnogenol treatment, thus adding further clinical evidence to its therapeutic efficacy in patients with CVI. Pycnogenol was effective, probably by either stabilizing the collagenous subendothelial basal membrane or scavenging the free radicals, or by a combination of these activities. Clinically, capillary leakage, perivascular inflammation and subcutaneous edema were all reduced. The safety of use of Pycnogenol is demonstrated by the lack of side effects or changes in blood biochemistry and hematologic parameters. Pycnogenol can be therefore recommended both for prevention and treatment of CVI and related veno-capillary disturbances.

21. Phytother Res. 2000 Sep;14(6):472-3.

Inhibition of lipogenesis by pycnogenol.

Hasegawa N.

Department of Food and Nutrition, Nagoya Bunri College, Nagoya, Japan.

The influence of pycnogenol on the adipose conversion of 3T3-L1 cells by insulin was studied. In week 3 of culture with insulin, pycnogenol was found to inhibit significantly the expression of glycerophosphate dehydrogenase (p < 0.01). This finding suggests that pycnogenol inhibits the accumulation of lipid droplets in adipose tissue. Copyright 2000 John Wiley & Sons, Ltd.

22. Anticancer Res. 2000 Jul-Aug;20(4):2417-20.

Selective induction of apoptosis in human mammary cancer cells (MCF-7) by pycnogenol.

Huynh HT, Teel RW.

Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA 92350, USA.

Breast cancer is the second leading cause of cancer death in women in the United States. The 1999 Cancer Facts and Figures, published by the American Cancer Society, estimates that almost 43,700 women and men will die of breast cancer in the United States. In this study, we compared the response of human breast cancer cells (MCF-7) and normal human mammary cells (MCF-10) to apoptosis in the presence of pycnogenol. Pycnogenol is a mixture of flavonoid compounds extracted from the bark of pine trees. MCF-7 and MCF-10 cells were plated out in culture dishes and grown in medium containing 0, 40, or 80 micrograms pycnogenol/ml culture medium. Cells were harvested at confluency, incubated with DAPI for 15 min and viewed microscopically for evidence of apoptosis. Apoptosis is detectable by morphology, chromatin condensation, nuclear DNA fragmentation, DNA strand breakage or apoptotic bodies. DAPI is a DNA-binding fluorescent dye used to visualize DNA fragmentation. Apoptosis, as detected by DAPI staining, was significantly higher in MCF-7 cells treated with pycnogenol than the untreated cells. The presence of pycnogenol did not significantly alter the number of apoptotic cells in MCF-10 samples. These results suggest that pycnogenol selectively induced death in human mammary cancer cells (MCF-7) and not in normal human mammary MCF-10 cells.

23. Cell Mol Life Sci. 2000 May;57(5):834-41.

Pycnogenol inhibits tumor necrosis factor-alpha-induced nuclear factor kappa B activation and adhesion molecule expression in human vascular endothelial cells.

Peng Q, Wei Z, Lau BH.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, California 92350, USA.

The transcriptional regulatory protein nuclear factor kappa B (NF-kappa B) participates in the control of gene expression of many modulators of inflammatory and immune responses, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). The heightened expression of these adhesion molecules has been reported to play a critical role in atherosclerosis, inflammation, ischemic vascular disorders, diabetes, and cancer metastasis. In the present study, we investigated the effect of pycnogenol, an antioxidant phytochemical, on the activation of NF-kappa B and the induction of VCAM-1 and ICAM-1 in tumor necrosis factor (TNF)-alpha-treated human umbilical vein endothelial cells (HUVECs). Gel-shift analysis of HUVEC demonstrated that pretreatment with pycnogenol exhibited a concentration-dependent suppression of TNF-alpha-induced activation of NF-kappa B. Induction of VCAM-1 and ICAM-1 surface expression by TNF-alpha was dose-dependently reduced by pycnogenol. TNF-alpha significantly increased the release of superoxide anion and hydrogen peroxide from HUVECs. Pycnogenol dose-dependently inhibited their release. The ability of pycnogenol to inhibit NF-kappa B activation and VCAM-1 and ICAM-1 expression suggests that this phytochemical may play an important role in halting or preventing the atherogenic process.

24. Biol Pharm Bull. 2000 Jun;23(6):735-7.

Pycnogenol protects vascular endothelial cells from beta-amyloid-induced injury.

Liu F, Lau BH, Peng Q, Shah V.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, CA 92350, USA.

The neuropathological hallmarks of Alzheimer's disease (AD) are senile plaques, cerebrovascular beta-amyloidosis, neurofibrillary tangles, and selective neuronal loss. Beta-amyloid (Abeta) has been shown to cause vascular damage mediated by generation of reactive oxygen species and this damage is considered an early event in the development of AD. In this study, we determined the effect of pyenogenol, a potent antioxidant phytochemical, on Abeta-induced cellular injury. Pulmonary artery endothelial cells (PAEC) were exposed to Abeta for 24 h. Cell injury was assessed by measuring cell viability with methylthiazol tetrazolium (MTT) assay, and by determining the release of intracellular lactate dehydrogenase (LDH). Lipid peroxidation products of PAEC were determined by measuring thiobarbituric acid-reactive substances (TBARS). Exposure of PAEC to Abeta resulted in a decrease in cell viability, an increase of LDH release indicating membrane damage, and an elevated level of TBARS. Preincubation of PAEC with pycnogenol significantly minimized these changes. This study demonstrated that pycnogenol can protect vascular endothelial cells from Abeta-induced injury. The data suggest that pycnogenol may be useful for the prevention and/or treatment of vascular or neurodegenerative diseases associated with Abeta toxicity.

25. Fitoterapia. 2000 Jun;71(3):236-44.

Pycnogenol in chronic venous insufficiency.

Arcangeli P.

Professore di Clinica Medica Generale e Terapia Medica, Universita degli Studi di Firenze, Via Marsilio Ficino 10, I-50122, Firenze, Italy.

Forty patients with chronic venous insufficiency (CVI) and varices of the legs were selected and double-blindly randomly assigned to a treatment with Pycnogenol (French maritime pine bark extract), 100 mg x 3/day or a placebo for 2 months, according to a double-blind experimental design. The effects of the treatment were evaluated by scoring the symptomatology with a semi-quantitative scale, and the venous blood flow by means of a hand-held Doppler ultrasound. The tolerability was evaluated by recording the adverse effects and by means of hematology and blood chemistry parameters, before and at the end of the treatment. Pycnogenol treatment induced a significant reduction in subcutaneous edema as well as heaviness and pain in the legs, on both after 30 and 60 days, the evaluation time periods. Approximately 60% of patients treated with Pycnogenol(R) experienced a complete disappearance of edema (the most rapidly disappearing symptom) and pain at the end of the treatment, while almost all the patients reported a reduction in leg heaviness which disappeared in approximately 33% of patients. These changes were statistically significant. No effect was observed in the placebo-treated subjects. No effect on the venous blood flow was observed in either of the experimental groups.

26. Phytother Res. 1999 Nov;13(7):619-20.

Stimulation of lipolysis by pycnogenol.

Hasegawa N.

Department of Food and Nutrition, Nagoya Bunri College, Nagoya, Japan.

We studied the influence of pycnogenol on the lipolysis of 3T3 L1 cells after differentiation. When pycnogenol or epinephrine was exposed to mature adipocytes, the smaller (less than 20 microm(2)) intracytoplasmic lipid droplets selectively disappeared. These data suggest that pycnogenol stimulates lipolysis. Copyright 1999 John Wiley & Sons, Ltd.

27. Thromb Res. 1999 Aug 15;95(4):155-61.

Inhibition of smoking-induced platelet aggregation by aspirin and pycnogenol.

Putter M, Grotemeyer KH, Wurthwein G, Araghi-Niknam M, Watson RR, Hosseini S, Rohdewald P.

Department of Neurology, Westfalische Wilhelms-Universitat Munster, Germany.

The effects of a bioflavonoid mixture, Pycnogenol, were assessed on platelet function in humans. Cigarette smoking increased heart rate and blood pressure. These increases were not influenced by oral consumption of Pycnogenol or Aspirin just before smoking. However, increased platelet reactivity yielding aggregation 2 hours after smoking was prevented by 500 mg Aspirin or 100 mg Pycnogenol in 22 German heavy smokers. In a group of 16 American smokers, blood pressure increased after smoking. It was unchanged after intake of 500 mg Aspirin or 125 mg Pycnogenol. In another group of 19 American smokers, increased platelet aggregation was more significantly reduced by 200 than either 150 mg or 100 mg Pycnogenol supplementation. This study showed that a single, high dose, 200 mg Pycnogenol, remained effective for over 6 days against smoking-induced platelet aggregation. Smoking increased platelet aggregation that was prevented after administration of 500 mg Aspirin and 125 mg Pycnogenol. Thus, smoking-induced enhanced platelet aggregation was inhibited by 500 mg Aspirin as well as by a lower range of 100-125 mg Pycnogenol. Aspirin significantly (p<0.001) increased bleeding time from 167 to 236 seconds while Pycnogenol did not. These observations suggest an advantageous risk-benefit ratio for Pycnogenol.

28. Free Radic Biol Med. 1999 Sep;27(5-6):704-24.

Antioxidant activity and biologic properties of a procyanidin-rich extract from pine (Pinus maritima) bark, pycnogenol.

Packer L, Rimbach G, Virgili F.

Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.

There is growing interest in the biologic activities of plant extracts such as that obtained from the bark of the French maritime pine Pinus maritima, Pycnogenol. Pycnogenol (PYC) is a standardized extract composed of a mixture of flavonoids, mainly procyandins and phenolic acids. Studies indicate that PYC components are highly bioavailable. Uniquely PYC displays greater biologic effects as a mixture than its purified components do individually indicating that the components interact synergistically. PYC has been reported to have cardiovascular benefits, such as a vasorelaxant activity, angiotensin-converting enzyme (ACE) inhibiting activity, and the ability to enhance the microcirculation by increasing capillary permeability. Investigations of the cellular mechanisms of these therapeutic effects have demonstrated that PYC has strong free radical-scavenging activity against reactive oxygen and nitrogen species. The oligomeric components of PYC contribute significantly to the ESR free radical signal. PYC also participates in the cellular antioxidant network as indicated by its ability to regenerate the ascorbyl radical and to protect endogenous vitamin E and glutathione from oxidative stress. PYC modulates NO metabolism in activated macrophages by quenching the NO radical and inhibiting both iNOS mRNA expression and iNOS activity. The spectrum of different effects of NO in the circulation and the nervous system suggest the potential applications of PYC in immune and circulatory disorders as well as in neurodegenerative disease. PYC can bind to proteins, altering their structure and thereby modulating the activity of key enzymes and proteins involved in metabolic pathways. PYC effects redox-sensitive signal transduction pathways and alters gene expression. Aspects of PYC's activity are presented and discussed together with possible future implications and directions in the field of flavonoid research.

29. Anticancer Res. 1999 May-Jun;19(3A):2095-9.

Effects of intragastrically administered Pycnogenol on NNK metabolism in F344 rats.

Huynh HT, Teel RW.

Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA 92350, USA.

NNK is a tobacco-specific nitrosamine that requires metabolic activation by cytochrome P450 enzymes. NNK may be metabolized via carbonyl reduction, N-oxidation, and alpha-carbon hydroxylation. Pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark and is available as a dietary supplement. We have previously shown that Pycnogenol inhibits the in vitro metabolism of NNK in lung and liver microsomes of F344 rats in a concentration-dependent manner. In this report, intragastrically administered Pycnogenol in saline affected NNK metabolism in lung microsomes differently than in liver microsomes of F344 rats. The administered Pycnogenol was inhibitory toward NNK activation in lung microsomes but not in liver microsomes suggesting that Pycnogenol may afford chemoprotection toward NNK-induced lung tumorigenesis when administered orally but not toward NNK-induced liver tumorigenesis. The effects of intragastrically administered Pycnogenol on NNK metabolism in lung and liver microsomes were similar in 6 mo and 20 mo old rats although the level of NNK metabolism was less in the 20 mo old animals.

30. Cancer Lett. 1998 Oct 23;132(1-2):135-9.

Effects of pycnogenol on the microsomal metabolism of the tobacco-specific nitrosamine NNK as a function of age.

Huynh HT, Teel RW.

Department of Physiology and Pharmacology, Loma Linda University, School of Medicine, CA 92350, USA.

NNK is a potent environmental carcinogen to which smokers and non-smokers are exposed. The response to NNK can be altered by various factors including nutrition. In this study, we examined the effects of pycnogenol on the in vitro metabolism of the tobacco-specific nitrosamine NNK by liver and lung microsomes from 6- and 20-month-old male F344 rats. The major NNK metabolic pathway in liver microsomes was carbonyl reduction, while alpha-hydroxylation was the major pathway in lung microsomes irrespective of age. Pycnogenol (40 and 120 microg/ml) exhibited a statistically significant inhibition of carbonyl reduction and alpha-hydroxylation pathways in liver microsomes from both age groups and in addition to these pathways, pycnogenol inhibited the N-oxidation pathway in lung microsomes. The liver and lung microsomes from 20-month-old rats were less active than from 6-month-old rats although the difference was not statistically significant.

31. Cell Mol Life Sci. 1998 Oct;54(10):1168-72.

Pycnogenol enhances immune and haemopoietic functions in senescence-accelerated mice.

Liu FJ, Zhang YX, Lau BH.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, California 92350, USA.

Pycnogenol (procyanidin extracted from Pinus maritima) has been shown to be a potent free radical scavenger and an antioxidant phytochemical. The effects of pycnogenol on immune and haemopoietic dysfunction in senescence-accelerated mice (SAM), as a murine model of accelerated ageing, were determined. SAMP8, a strain of senile-prone mice, exhibit learning and memory deficits, immunodeficiency and dysfunction of the haemopoietic system. Oral feeding with pycnogenol for 2 months significantly improved their T- and B-cell function. Pycnogenol also augmented the proliferative capacity of haemopoietic progenitors of bone marrow in SAMP8. These data suggest that pycnogenol may be useful for either retardation or restoration of parameters associated with ageing.

32. J Cardiovasc Pharmacol. 1998 Oct;32(4):509-15.

Endothelium-dependent vascular effects of Pycnogenol.

Fitzpatrick DF, Bing B, Rohdewald P.

Department of Pharmacology, University of South Florida, Tampa 33612, USA.

Pycnogenol (P) is purported to exhibit effects that could be beneficial in terms of prevention of chronic age-related diseases such as atherosclerosis. The most studied of these effects is its antioxidant/free radical-scavenging activity. In this study, we investigated the possibility that this supplement might produce vascular effects by stimulation of nitric oxide (NO) production by vascular endothelial cells. In the in vitro experiments, P (1-10 microg/ml) relaxed epinephrine (E)-, norepinephrine (NE)-, and phenylephrine (PE)-contracted intact rat aortic ring preparations in a concentration-dependent manner. However, when the endothelial lining of the aortic ring was removed, P had no effect, indicating an endothelium-dependent relaxing (EDR) effect. This EDR response was caused by enhanced NO levels, because the NO synthase (NOS) inhibitor N-methyl-L-arginine (NMA) reversed (or prevented) the relaxation, and this response, in turn, was reversed by addition of L-arginine, the normal substrate for NOS. Pycnogenol-induced EDR persisted after exposure of intact rings to high levels of superoxide dismutase (SOD), suggesting that the mechanism of EDR did not involve scavenging of superoxide anion. In addition to causing relaxation, preincubation of aortic rings with P (1-10 microg/ml) inhibited subsequent E- and NE-induced contractions in a concentration-dependent manner. Fractionation of P by Sephadex LH-20 chromatography resulted in three fractions, one of which (fraction 3, oligomeric procyanidins) exhibited potent EDR activity. These results indicate that P, in addition to its antioxidant activity, stimulates constitutive endothelial NOS (eNOS) activity to increase NO levels, which could counteract the vasoconstrictor effects of E and NE. Furthermore, additional protective effects could result from the well-established properties of NO to decrease platelet aggregation and adhesion, as well as to inhibit low-density lipoprotein (LDL) cholesterol oxidation, all of which could protect against atherogenesis and thrombus formation.

33. Free Radic Biol Med. 1998 May;24(7-8):1120-9.

Procyanidins extracted from Pinus maritima (Pycnogenol): scavengers of free radical species and modulators of nitrogen monoxide metabolism in activated murine RAW 264.7 macrophages.

Virgili F, Kobuchi H, Packer L.

Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.

Nitrogen monoxide (NO) has diverse physiological roles and also contributes to the immune defense against viruses, bacteria, and other parasites. However, excess production of NO is associated with various diseases such arthritis, diabetes, stroke, septic shock, autoimmune, chronic inflammatory diseases, and atheriosclerosis. Cells respond to activating or depressing stimuli by enhancing or inhibiting the expression of the enzymatic machinery that produce NO. Thus, maintenance of a tight regulation of NO production is important for human health. Phytochemicals have been traditionally utilized in ways to treat a family of pathologies that have in common the disregulation of NO production. Here we report the scavenging activity of Pycnogenol (the polyphenols containing extract of the bark from Pinus maritima) against reactive oxygen and nitrogen species, and its effects on NO metabolism in the murine macrophages cell line RAW 264.7. Macrophages were activated by the bacterial wall components lipopolysaccharide (LPS) and interferon (IFN-gamma), which induces the expression of large amounts of the enzyme nitric oxide synthase (iNOS). Preincubation of cells with physiological concentrations of Pycnogenol significantly decreased NO generation. It was found that this effect was due to the combination of several different biological activities, i.e., its ROS and NO scavenging activity, inhibition of iNOS activity, and inhibition of iNOS-mRNA expression. These data begin to provide the basis for the conceptual understanding of the biological activity of Pycnogenol and possibly other polyphenolic compounds as therapeutic agents in various human disorders.

34. Life Sci. 1996;58(5):PL 87-96.

Immunomodulation by pycnogenol in retrovirus-infected or ethanol-fed mice.

Cheshier JE, Ardestani-Kaboudanian S, Liang B, Araghiniknam M, Chung S, Lane L, Castro A, Watson RR.

Department of Family and Community Medicine, University of Arizona, Tucson 85724, USA.

Pycnogenol is a commercial mixture of bioflavonoids that exhibits antioxidative activity. The effects of dietary pycnogenol on immune dysfunction in normal mice as well as those fed ethanol or infected with the LP-BM5 murine retrovirus were determined. The ethanol consumption and retrovirus infection caused abnormalities in the function and/or structure of a broad array of cells involved in humoral and cellular immunity. Pycnogenol enhanced in vitro IL-2 production by mitogen-stimulated splenocytes if its production was suppressed in ethanol-fed or retrovirus-infected mice. Mitogenesis of splenocytes did not show a significant change in mice treated with pycnogenol. It reduced the elevated levels of interleukin-6 produced in vitro by cells from retrovirus infected mice and IL-10 secreted by spleen cells from mice consuming ethanol. Natural killer cell cytotoxicity was increased with pycnogenol treatment.

35. Biotechnol Ther. 1994-95;5(3-4):117-26.

Pycnogenol protects vascular endothelial cells from t-butyl hydroperoxide induced oxidant injury.

Rong Y, Li L, Shah V, Lau BH.

Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA.

The active oxygen induced and free radical mediated oxidation of biological molecules, membranes, and tissues has been suggested as a major cause of cancer, atherosclerosis, and aging. Damage of endothelial cells may lead to cardiovascular and cerebrovascular diseases. In the present study, the antioxidant effect of pycnogenol (procyanidins extracted from Pinus maritima) was investigated in vitro using vascular endothelial cells. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with different concentrations of pycnogenol for 16 h, washed, and then exposed to an organic oxidant t-butyl hydroperoxide (tBHP) for 3 or 4 h. Cellular injury was assessed by measuring cell viability with methylthiazol tetrazolium (MTT) assay and by determining the release of intracellular lactate dehydrogenase (LDH). Lipid peroxidation products of PAEC were monitored as malondialdehyde (MDA) with a thiobarbituric acid fluorometric assay. Incubation of tBHP (75, 100, or 125 microM) with PAEC decreased cell viability, increased LDH release, and elevated MDH production. Preincubation of PAEC with pycnogenol (10-80 micrograms/mL) before tBHP exposure significantly increased cell viability, decreased LDH release, and reduced MDA production. These results demonstrate that pycnogenol can protect vascular endothelial cells from oxidant injury. The data thus suggest that pycnogenol may be useful for the prevention of disorders associated with oxidative damage.