Life Extension Magazine

Life Extension Magazine July 2012

Abstracts

Blueberry

Whole blueberry powder modulates the growth and metastasis of MDA-MB-231 triple negative breast tumors in nude mice.

Previous studies in our laboratory demonstrated that blueberry (BB) extract exhibited antitumor activity against MDA-MB-231 triple negative breast cancer (TNBC) cells and decreased metastatic potential in vitro. The current study tested 2 doses of whole BB powder, 5 and 10% (wt:wt) in the diet, against MDA-MB-231 tumor growth in female nude mice. In this study, tumor volume was 75% lower in mice fed the 5% BB diet and 60% lower in mice fed the 10% BB diet than in control mice (P ≤ 0.05). Tumor cell proliferation (Ki-67) was lower in the 5 and 10% BB-fed mice and cell death (Caspase 3) was greater in the 10% BB-fed mice compared to control mice (P ≤ 0.05). Gene analysis of tumor tissues from the 5% BB-fed mice revealed significantly altered expression of genes important to inflammation, cancer, and metastasis, specifically, Wnt signaling, thrombospondin-2, IL-13, and IFN. To confirm effects on Wnt signaling, analysis of tumor tissues from 5% BB-fed mice revealed lower -catenin expression and glycogen synthase kinase-3 phosphorylation with greater expression of the-catenin inhibitory protein adenomatous polyposis coli compared to controls. A second study tested the ability of the 5% BB diet to inhibit MDA-MB-231-luc-D3H2LN metastasis in vivo. In this study, 5% BB-fed mice developed 70% fewer liver metastases (P = 0.04) and 25% fewer lymph node metastases (P = 0.09) compared to control mice. This study demonstrates the oral antitumor and metastasis activity of whole BB powder against TNBC in mice.

Nutr. 2011 Oct;141(10):1805-12

An evaluation of the effect of a topical product containing C-xyloside and blueberry extract on the appearance of type II diabetic skin.

BACKGROUND: Diabetes is a multisystem disease caused by the presence of chronic hyperglycemia, which leads to increased oxidative stress. Many of the changes observed in type II diabetic patients can be traced to the increased production of advanced glycation end products, also known as AGEs. AGEs are produced as a result of a nonenzymatic reaction with glucose interacting with proteins, lipids, and nucleic acids. AGEs are also present in normal skin with advancing age and contribute to the senescence of many body organs, including the skin. AIMS: This research evaluated the effect of a topical product formulation containing blueberry extract, an AGE inhibitor, and C-xyloside, a GAG synthesis stimulator, applied twice daily on the hand, arm, and facial skin of 20 type II diabetic females. Diabetic skin was chosen for evaluation because AGEs are found in increased concentration in diabetic skin, representing a model for accelerated aging. MATERIALS AND METHODS: This single-center study enrolled 20 female type II diabetics aged 55+ years with mild to moderate fine lines, wrinkles, and hyperpigmentation on the face and hands. Subjects used the study product on their face, hand, and inner forearm twice daily for 12 weeks. Ordinal grading on a 4-point scale (0 = none, 1 = mild, 2 =moderate, 3 = severe) of facial fine lines, wrinkles, firmness, radiance, skin tone, skin smoothness, hyperpigmentation, creping, density, sagging, and overall appearance was performed by the investigator at baseline, week 4, week 8, and week 12. Tolerability, subject assessments, digital photography, AGE measurements, skin caliper measurements, and corneometry were also performed at each time point. RESULTS: 19/20 subjects successfully completed the study. The presence of AGEs was documented by skin autofluorescence. The 12-week duration of the study was insufficient to measure a change in skin AGEs, but longer application of the study product might produce different results. No tolerability issues were noted. There was a statistically significant increase in skin caliper measurements on the face (P = 0.004) and arm (P = 0.014) as well as corneometry measurements (P < 0.001) consistent with enhanced moisturization at week 12. The dermatologist investigator also found statistically significant improvement in fine lines (P = 0.01), firmness (P = 0.011), radiance (P < 0.001), skin tone (P = 0.014), skin smoothness (P < 0.001), creping (P < 0.004), and overall appearance (P < 0.001). CONCLUSION: This study examined a topical product containing an AGE inhibitor and a GAG synthesis stimulator designed for the unique needs of diabetic skin.

Cosmet Dermatol. 2009 Jun;8(2):147-51

Blueberry polyphenols increase life span and thermotolerance in Caenorhabditis elegans.

The beneficial effects of polyphenol compounds in fruits and vegetables are mainly extrapolated from in vitro studies or short-term dietary supplementation studies. Due to cost and duration, relatively little is known about whether dietary polyphenols are beneficial in whole animals, particularly with respect to aging. To address this question, we examined the effects of blueberry polyphenols on life span and aging of the nematode, Caenorhabditis elegans, a useful organism for such a study. We report that a complex mixture of blueberry polyphenols increased life span and slowed aging-related declines in C. elegans. We also found that these benefits did not just reflect antioxidant activity in these compounds. For instance, blueberry treatment increased survival during acute heat stress, but was not protective against acute oxidative stress. The blueberry extract consists of three major fractions that all contain antioxidant activity. However, only one fraction, enriched in proanthocyanidin compounds, increased C. elegans life span and thermotolerance. To further determine how polyphenols prolonged C. elegans life span, we analyzed the genetic requirements for these effects. Prolonged life span from this treatment required the presence of a CaMKII pathway that mediates osmotic stress resistance, though not other pathways that affect stress resistance and longevity. In conclusion, polyphenolic compounds in blueberries had robust and reproducible benefits during aging that were separable from antioxidant effects.

Aging Cell. 2006 Feb;5(1):59-68

Bioactives in blueberries improve insulin sensitivity in obese, insulin-resistant men and women.

Dietary supplementation with whole blueberries in a preclinical study resulted in a reduction in glucose concentrations over time. We sought to evaluate the effect of daily dietary supplementation with bioactives from blueberries on whole-body insulin sensitivity in men and women. A double-blinded, randomized, and placebo-controlled clinical study design was used. After screening to resolve study eligibility, baseline (wk 0) insulin sensitivity was measured on 32 obese, nondiabetic, and insulin-resistant subjects using a high-dose hyperinsulinemic-euglycemic clamp (insulin infusion of 120 mU(861 pmol)⋅m(-2)⋅min(-1)). Serum inflammatory biomarkers and adiposity were measured at baseline. At the end of the study, insulin sensitivity, inflammatory biomarkers, and adiposity were reassessed. Participants were randomized to consume either a smoothie containing 22.5 g blueberry bioactives (blueberry group, n = 15) or a smoothie of equal nutritional value without added blueberry bioactives (placebo group, n = 17) twice daily for 6 wk. Both groups were instructed to maintain their body weight by reducing ad libitum intake by an amount equal to the energy intake of the smoothies. Participants’ body weights were evaluated weekly and 3-d food records were collected at baseline, the middle, and end of the study. The mean change in insulin sensitivity improved more in the blueberry group (1.7 ± 0.5 mg⋅kg FFM(-1)⋅min(-1)) than in the placebo group (0.4 ± 0.4 mg⋅kg FFM(-1)⋅min(-1)) (P = 0.04). Insulin sensitivity was enhanced in the blueberry group at the end of the study without significant changes in adiposity, energy intake, and inflammatory biomarkers. In conclusion, daily dietary supplementation with bioactives from whole blueberries improved insulin sensitivity in obese, nondiabetic, and insulin-resistant participants.

J Nutr. 2010 Oct;140(10):1764-8

Blueberries decrease cardiovascular risk factors in obese men and women with metabolic syndrome.

Among all fruits, berries have shown substantial cardio-protective benefits due to their high polyphenol content. However, investigation of their efficacy in improving features of metabolic syndrome and related cardiovascular risk factors in obesity is limited. We examined the effects of blueberry supplementation on features of metabolic syndrome, lipid peroxidation, and inflammation in obese men and women. Forty-eight participants with metabolic syndrome [4 males and 44 females; BMI: 37.8 +/- 2.3 kg/m(2); age: 50.0 +/- 3.0 y (mean +/- SE)] consumed freeze-dried blueberry beverage (50 g freeze-dried blueberries, approximately 350 g fresh blueberries) or equivalent amounts of fluids (controls, 960 mL water) daily for 8 wk in a randomized controlled trial. Anthropometric and blood pressure measurements, assessment of dietary intakes, and fasting blood draws were conducted at screening and at wk 4 and 8 of the study. The decreases in systolic and diastolic blood pressures were greater in the blueberry-supplemented group (- 6 and - 4%, respectively) than in controls (- 1.5 and - 1.2%) (P lt 0.05), whereas the serum glucose concentration and lipid profiles were not affected. The decreases in plasma oxidized LDL and serum malondialdehyde and hydroxynonenal concentrations were greater in the blueberry group (- 28 and - 17%, respectively) than in the control group (- 9 and - 9%) (P lt 0.01). Our study shows blueberries may improve selected features of metabolic syndrome and related cardiovascular risk factors at dietary achievable doses.

J Nutr. 2010 Sep;140(9):1582-7

Blueberry-enriched diet protects rat heart from ischemic damage.

OBJECTIVES: to assess the cardioprotective properties of a blueberry enriched diet (BD). BACKGROUND: Reactive oxygen species (ROS) play a major role in ischemia-related myocardial injury. The attempts to use synthetic antioxidants to block the detrimental effects of ROS have produced mixed or negative results precipitating the interest in natural products. Blueberries are readily available product with the highest antioxidant capacity among fruits and vegetables. METHODS AND RESULTS: Following 3-mo of BD or a regular control diet (CD), the threshold for mitochondrial permeability transition (t(MPT)) was measured in isolated cardiomyocytes obtained from young male Fischer-344 rats. Compared to CD, BD resulted in a 24% increase (p<0.001) of ROS indexed t(MPT). The remaining animals were subjected to a permanent ligation of the left descending coronary artery. 24 hrs later resulting myocardial infarction (MI) in rats on BD was 22% less than in CD rats (p<0.01). Significantly less TUNEL(+) cardiomyocytes (2% vs 9%) and 40% less inflammation cells were observed in the myocardial area at risk of BD compared to CD rats (p<0.01). In the subgroup of rats, after coronary ligation the original diet was either continued or switched to the opposite one, and cardiac remodeling and MI expansion were followed by serial echocardiography for 10 weeks. Measurements suggested that continuation of BD or its withdrawal after MI attenuated or accelerated rates of post MI cardiac remodeling and MI expansion. CONCLUSION: A blueberry-enriched diet protected the myocardium from induced ischemic damage and demonstrated the potential to attenuate the development of post MI chronic heart failure.

PLoS One. 2009 Jun 18;4(6):e5954

Phenolic compounds from blueberries can inhibit colon cancer cell proliferation and induce apoptosis.

Research has shown that diets rich in phenolic compounds may be associated with lower risks of several chronic diseases including cancer. This study systematically evaluated the bioactivities of phenolic compounds in rabbiteye blueberries and assessed their potential antiproliferation and apoptosis induction effects using two colon cancer cell lines, HT-29 and Caco-2. Polyphenols in three blueberry cultivars, Briteblue, Tifblue, and Powderblue, were extracted and freeze-dried. The extracts were further separated into phenolic acids, tannins, flavonols, and anthocyanins using an HLB cartridge and LH20 column. Some individual phenolic acids and flavonoids were identified by HPLC with >90% purity in anthocyanin fractions. The dried extracts and fractions were added to the cell culture medium to test for antiproliferation activities and induction of apoptosis. Flavonol and tannin fractions resulted in 50% inhibition of cell proliferation at concentrations of 70-100 and 50-100 microg/mL in HT-29 and Caco-2 cells, respectively. The phenolic acid fraction showed relatively lower bioactivities with 50% inhibition at approximately 1,000 microg/mL. The greatest antiproliferation effect among all four fractions was from the anthocyanin fractions. Both HT-29 and Caco-2 cell growth was significantly inhibited by >50% by the anthocyanin fractions at concentrations of 15-50 microg/mL. Anthocyanin fractions also resulted in 2-7 times increases in DNA fragmentation, indicating the induction of apoptosis. The effective dosage levels are close to the reported range of anthocyanin concentrations in rat plasma. These findings suggest that blueberry intake may reduce colon cancer risk.

J Agric Food Chem. 2005 Sep 7;53(18):7320-9

Oral administration of blueberry inhibits angiogenic tumor growth and enhances survival of mice with endothelial cell neoplasm.

Endothelial cell neoplasms are the most common soft tissue tumor in infants. Subcutaneous injection of spontaneously transformed murine endothelial (EOMA) cells results in development of hemangioendothelioma (HE). We have previously shown that blueberry extract (BBE) treatment of EOMA cells in vitro prior to injection in vivo can significantly inhibit the incidence and size of developing HE. In this study, we sought to determine whether oral BBE could be effective in managing HE and to investigate the mechanisms through which BBE exerts its effects on endothelial cells. A dose-dependent decrease in HE tumor size was observed in mice receiving daily oral gavage feeds of BBE. Kaplan-Meier survival curve showed significantly enhanced survival for mice with HE tumors given BBE, compared to control. BBE treatment of EOMA cells inhibited both c-Jun N-terminal kinase (JNK) and NF-kappaB signaling pathways that culminate in monocyte chemoattractant protein-1 (MCP-1) expression required for HE development. Antiangiogenic effects of BBE on EOMA cells included decreased proliferation by BrdU assay, decreased sprouting on Matrigel, and decreased transwell migration. Thus, this work provides first evidence demonstrating that BBE can limit tumor formation through antiangiogenic effects and inhibition of JNK and NF-kappaB signaling pathways. Oral administration of BBE represents a potential therapeutic antiangiogenic strategy for treating endothelial cell neoplasms in children.

Antioxid Redox Signal. 2009 Jan;11(1):47-58

Blueberry anthocyanins: protection against ageing and light-induced damage in retinal pigment epithelial cells.

Retinal pigment epithelium (RPE) cells are vital for retinal health. However, they are susceptible to injury with ageing and exposure to excessive light, including UV (100-380 nm) and visible (380-760 nm) radiation. To evaluate the protective effect of blueberry anthocyanins on RPE cells, in vitro cell models of replicative senescent and light-induced damage were established in the present study. After purification and fractionation, blueberry anthocyanin extracts (BAE) were yielded with total anthocyanin contents of 31•0 (sd 0•5) % and were used in this study. Replicative senescence of RPE cells was induced by repeatedly passaging cells from the fourth passage to the tenth. From the fifth passage, cultured RPE cells began to enter a replicative senescence, exhibiting reduced cell proliferation along with an increase in the number of β-galactosidase-positive cells. RPE cells maintained high cell viability (P < 0•01) and a low (P < 0•01) percentage of β-galactosidase-positive cells when treated with 0•1 µg/ml BAE. In contrast, after exposure to 2500 (sd 500) lx light (420-800 nm) for 12 h, RPE cells in the positive control (light exposure, no BAE treatment) exhibited premature senescence, low (P < 0•01) cell viability and increased (P < 0•01) vascular endothelial growth factor (VEGF) release compared with negative control cells, which were not subjected to light irradiation and BAE exposure. Correspondingly, BAE is beneficial to RPE cells by protecting these cells against light-induced damage through the suppression of ageing and apoptosis as well as the down-regulation of the over-expressed VEGF to normal level. These results demonstrate that BAE is efficacious against senescence and light-induced damage of RPE cells.

Br J Nutr. 2011 Oct 12:1-12

Age-related toxicity of amyloid-beta associated with increased pERK and pCREB in primary hippocampal neurons: reversal by blueberry extract.

Further clarification is needed to address the paradox that memory formation, aging and neurodegeneration all involve calcium influx, oxyradical production (ROS) and activation of certain signaling pathways. In aged rats and in APP/PS-1 mice, cognitive and hippocampal Ca(2+) dysregulation was reversed by food supplementation with a high antioxidant blueberry extract. Here, we studied whether neurons were an important target of blueberry extract and whether the mechanism involved altered ROS signaling through MAP kinase and cyclic-AMP response element binding protein (CREB), pathways known to be activated in response to amyloid-beta (Aβ). Primary hippocampal neurons were isolated and cultured from embryonic, middle-age or old-age (24 months) rats. Blueberry extract was found to be equally neuroprotective against Aβ neurotoxicity at all ages. Increases in Aβ toxicity with age were associated with age-related increases in immunoreactivity of neurons to pERK and an age-independent increase in pCREB. Treatment with blueberry extract strongly inhibited these increases in parallel with neuroprotection. Simultaneous labeling for ROS and for glutathione with dichlorofluorescein and monochlorobimane showed a mechanism of action of blueberry extract to involve transient ROS generation with an increase in the redox buffer glutathione. We conclude that the increased age-related susceptibility of old-age neurons to Aβ toxicity may be due to higher levels of activation of pERK and pCREB pathways that can be protected by blueberry extract through inhibition of both these pathways through an ROS stress response. These results suggest that the beneficial effects of blueberry extract may involve transient stress signaling and ROS protection that may translate into improved cognition in aging rats and APP/PS1 mice given blueberry extract.

J Nutr Biochem. 2010 Oct;21(10):991-8

Inhibitory effect of blueberry polyphenolic compounds on oleic acid-induced hepatic steatosis in vitro.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide and is closely associated with metabolic syndromes, such as obesity, diabetes, and insulin resistance. Nonalcoholic fatty liver (NAFL), also called simple steatosis, is the initial phase of NAFLD, which is accompanied the characteristic pathological overaccumulation of lipids without inflammation. To prevent NAFLD from reaching the NAFL stage through dietary therapy, in the present work, wild Chinese blueberries (Vacciniun spp.) were selected for their well-known benefits in inhibiting metabolic syndrome. After being purified from wild Chinese blueberries, polyphenol-rich extracts were subsequently separated into three fractions, namely, anthocyanin-rich fraction, phenolic acid-rich fraction, and ethyl acetate extract. The inhibition of oleic acid (OA)-induced triglyceride (TG) deposition in HepG 2 cells was referred to as the potential activity of preventing NAFL. Biochemical indicators, such as cytotoxicity, TG level, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and intracellular reactive oxygen species, were used to evaluate the analogous pathological stage of NAFLD. The results show that OA ≤ 1.0 mM exhibits a dose-dependent induction of TG accumulation, and no inflammation was observed based on the changes in ALT and AST levels. Therefore, 1.0 mM OA was used to simulate an in vitro fatty liver. Blueberry polyphenol-rich extract efficiently inhibited OA-induced TG accumulation in HepG2 cells, and the phenolic acid-rich fraction performed efficiently. Seven phenolic acids were subsequently identified using a high-performance liquid chromatography assay, and the main types were caffeic, chlorogenic, ferulic, p-coumaric, and cinnamic acids. These phenolic acid standards also displayed good efficiency in inhibiting TG accumulation in HepG2 cells. These results imply that wild Chinese blueberries have a potential preventive effect on NAFLD in its early stage, and phenolic acids are the most efficient component.

J Agric Food Chem. 2011 Nov 23;59(22):12254-63