Cancer chemoprevention by pomegranate: laboratory and clinical evidence.
Pomegranate fruit from the tree Punica granatum has been dubbed as the “nature’s power fruit.” Dating back to Biblical times, the tree itself is attributed to possess extraordinary medicinal properties. The geographical distribution of the tree, being native to the Middle East and some Asian countries, is generally attributed to a lack of interest in its medicinal properties by many western scientists. However, the unique biochemical composition of the pomegranate fruit being rich in antioxidant tannins and flavonoids has recently drawn attention of many investigators to study its exceptional healing qualities. Recent research has shown that pomegranate extracts selectively inhibit the growth of breast, prostate, colon and lung cancer cells in culture. In preclinical animal studies, oral consumption of pomegranate extract inhibited growth of lung, skin, colon and prostate tumors. An initial phase II clinical trial of pomegranate juice in patients with prostate cancer reported significant prolongation of prostate specific antigen doubling time. This review focuses on recent investigations into the effects of pomegranate fruit on cancer.
Nutr Cancer. 2009;61(6):811-5
Comparative effects of dried plum and dried apple on bone in postmenopausal women.
Aside from existing drug therapies, certain lifestyle and nutritional factors are known to reduce the risk of osteoporosis. Among the nutritional factors, dried plum or prunes (Prunus domestica L.) is the most effective fruit in both preventing and reversing bone loss. The objective of the present study was to examine the extent to which dried plum reverses bone loss in osteopenic postmenopausal women. We recruited 236 women, 1-10 years postmenopausal, not on hormone replacement therapy or any other prescribed medication known to influence bone metabolism. Qualified participants (n 160) were randomly assigned to one of the two treatment groups: dried plum (100 g/d) or dried apple (comparative control). Participants received 500 mg Ca plus 400 IU (10 µg) vitamin D daily. Bone mineral density (BMD) of lumbar spine, forearm, hip and whole body was assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry. Blood samples were collected at baseline, 3, 6 and 12 months to assess bone biomarkers. Physical activity recall and 1-week FFQ were obtained at baseline, 3, 6 and 12 months to examine physical activity and dietary confounders as potential covariates. Dried plum significantly increased BMD of ulna and spine in comparison with dried apple. In comparison with corresponding baseline values, only dried plum significantly decreased serum levels of bone turnover markers including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b. The findings of the present study confirmed the ability of dried plum in improving BMD in postmenopausal women in part due to suppressing the rate of bone turnover.
Br J Nutr. 2011 Sep;106(6):923-30
Pilot study of oral anthocyanins for colorectal cancer chemoprevention.
Naturally occurring anthocyanins possess colorectal cancer chemopreventive properties in rodent models. We investigated whether mirtocyan, an anthocyanin-rich standardized bilberry extract, causes pharmacodynamic changes consistent with chemopreventive efficacy and generates measurable levels of anthocyanins in blood, urine, and target tissue. Twenty-five colorectal cancer patients scheduled to undergo resection of primary tumor or liver metastases received mirtocyan 1.4, 2.8, or 5.6 grams (containing 0.5-2.0 grams anthocyanins) daily for 7 days before surgery. Bilberry anthocyanins were analyzed by high performance liquid chromatography (HPLC) with visible or mass spectrometric detection. Proliferation was determined by immunohistochemistry of Ki-67 in colorectal tumor. Concentrations of insulin-like growth factor (IGF)-I were measured in plasma. Mirtocyan anthocyanins and methyl and glucuronide metabolites were identified in plasma, colorectal tissue, and urine, but not in liver. Anthocyanin concentrations in plasma and urine were roughly dose-dependent, reaching approximately 179 ng/gram in tumor tissue at the highest dose. In tumor tissue from all patients on mirtocyan, proliferation was decreased by 7% compared with preintervention values. The low dose caused a small but nonsignificant reduction in circulating IGF-I concentrations. In conclusion, repeated administration of bilberry anthocyanins exerts pharmacodynamic effects and generates concentrations of anthocyanins in humans resembling those seen in Apc(Min) mice, a model of FAP adenomas sensitive to the chemopreventive properties of anthocyanins. Studies of doses containing <0.5 gram bilberry anthocyanins are necessary to adjudge whether they may be appropriate for development as colorectal cancer chemopreventive agents.
Cancer Prev Res (Phila). 2009 Jul;2(7):625-33
Ellagic acid attenuates high-carbohydrate, high-fat diet-induced metabolic syndrome in rats.
BACKGROUND: Fruits and nuts may prevent or reverse common human health conditions such as obesity, diabetes and hypertension; together, these conditions are referred to as metabolic syndrome, an increasing problem. This study has investigated the responses to ellagic acid, present in many fruits and nuts, in a diet-induced rat model of metabolic syndrome. METHODS: Eight- to nine-week-old male Wistar rats were divided into four groups for 16-week feeding with cornstarch diet (C), cornstarch diet supplemented with ellagic acid (CE), high-carbohydrate, high-fat diet (H) and high-carbohydrate, high-fat diet supplemented with ellagic acid (HE). CE and HE rats were given 0.8 g/kg ellagic acid in food from week 8 to 16 only. At the end of 16 weeks, cardiovascular, hepatic and metabolic parameters along with protein levels of Nrf2, NF-kb and CPT1 in the heart and the liver were characterised. RESULTS: High-carbohydrate, high-fat diet-fed rats developed cardiovascular remodelling, impaired ventricular function, impaired glucose tolerance, non-alcoholic fatty liver disease with increased protein levels of NF-kb and decreased protein levels of Nrf2 and CPT1 in the heart and the liver. Ellagic acid attenuated these diet-induced symptoms of metabolic syndrome with normalisation of protein levels of Nrf2, NF-kb and CPT1. CONCLUSIONS: Ellagic acid derived from nuts and fruits such as raspberries and pomegranates may provide a useful dietary supplement to decrease the characteristic changes in metabolism and in cardiac and hepatic structure and function induced by a high-carbohydrate, high-fat diet by suppressing oxidative stress and inflammation.
Eur J Nutr.2012 Apr 27
The anti-diabetic effect of anthocyanins in streptozotocin-induced diabetic rats through glucose transporter 4 regulation and prevention of insulin resistance and pancreatic apoptosis.
Hyperglycemia, abnormal lipid and antioxidant profiles are the most usual complications in diabetes mellitus. Thus, in this study, we investigated the anti-diabetic and anti-oxidative effects of anthocyanins (ANT) from black soybean seed coats in streptozotocin (STZ)-induced diabetic rats. The administration of ANT markedly decreased glucose levels and improved heart hemodynamic function (left ventricular end diastolic pressure, +/-dp/dt parameters). ANT not only enhanced STZ-mediated insulin level decreases, but also decreased the triglyceride levels induced by STZ injection in serum. Diabetic rats exhibited a lower expression of glucose transporter 4 proteins in the membrane fractions of heart and skeletal muscle tissues, which was enhanced by ANT. In addition, ANT activated insulin receptor phosphorylation, suggesting an increased utilization of glucose by tissues. Moreover, ANT protected pancreatic tissue from STZ-induced apoptosis through regulation of caspase-3, Bax, and Bcl-2 proteins. Furthermore, ANT significantly suppressed malondialdehyde levels and restored superoxide dismutase and catalase activities in diabetic rats. Interestingly, the observed effects of ANT were superior to those of glibenclamide. Taken together, ANT from black soybean seed coat have anti-diabetic effects that are due, in part, to the regulation of glucose transporter 4 and prevention of insulin resistance and pancreatic apoptosis, suggesting a possible use as a drug to regulate diabetes.
Mol Nutr Food Res. 2009 Nov;53(11):1419-29
Isolation and identification of strawberry phenolics with antioxidant and human cancer cell antiproliferative properties.
Studies suggest that consumption of berry fruits, including strawberries (Fragaria x ananassa Duch.), may have beneficial effects against oxidative stress mediated diseases such as cancer. Berries contain multiple phenolic compounds, which are thought to contribute to their biological properties. Comprehensive profiling of phenolics from strawberries was previously reported using high-performance liquid chromatography with mass spectrometry (HPLC-MS) detection. The current study reports the isolation and structural characterization of 10 phenolic compounds from strawberry extracts using a combination of Amberlite XAD16-resin and C18 columns, HPLC-UV, and nuclear magnetic resonance (NMR) spectroscopy methods. The phenolics were cyanidin-3-glucoside ( 1), pelargonidin (2), pelargonidin-3-glucoside (3), pelargonidin-3-rutinoside (4), kaempferol (5), quercetin (6), kaempferol-3-(6’-coumaroyl)glucoside) (7), 3,4,5-trihydroxyphenyl-acrylic acid (8), glucose ester of ( E)- p-coumaric acid (9), and ellagic acid . Strawberry crude extracts and purified compounds 1- 10 were evaluated for antioxidant and human cancer cell antiproliferative activities by the Trolox equivalent antioxidant capacity (TEAC) and luminescent ATP cell viability assays, respectively. Among the pure compounds, the anthocyanins 1 (7,156 microM Trolox/mg), 2 (4,922 microM Trolox/mg), and 4 (5,514 microM Trolox/mg) were the most potent antioxidants. Crude extracts (250 microg/mL) and pure compounds (100 microg/mL) inhibited the growth of human oral (CAL-27, KB), colon (HT29, HCT-116), and prostate (LNCaP, DU145) cancer cells with different sensitivities observed between cell lines. This study adds to the growing body of data supporting the bioactivities of berry fruit phenolics and their potential impact on human health.
J Agric Food Chem. 2008 Feb 13;56(3):670-5
Multiple berry types preventN-nitrosomethylbenzylamine-induced esophageal cancer in rats.
PURPOSE: The present study compared the ability of different berry types to prevent chemically-induced tumorigenesis in the rat esophagus. We also determined if berries influence the levels of inflammatory cytokines in the serum of carcinogen-treated rats. METHODS: Rats were treated with the carcinogen N-nitrosomethylbenzylamine (NMBA) for 5 weeks, then placed on diets containing 5% of either black or red raspberries, strawberries, blueberries, noni, açaí or wolfberry until the end of the study. The effects of the berries on tumor incidence, multiplicity and size were determined, as well as their effects on the levels of selected inflammatory cytokines in serum. RESULTS: All berry types were about equally effective in inhibiting NMBA-induced tumorigenesis in the rat esophagus. They also reduced the levels of the serum cytokines, interleukin 5 (IL-5) and GRO/KC, the rat homologue for human interleukin-8 (IL-8), and this was associated with increased serum antioxidant capacity. CONCLUSIONS: Seven berry types were about equally capable of inhibiting tumor progression in the rat esophagus in spite of known differences in levels of anthocyanins and ellagitannins. Serum levels of IL-5 and GRO/KC (IL-8) may be predictive of the inhibitory effect of chemopreventive agents on rat esophageal carcinogenesis.
Pharm Res.2010 Jun;27(6):1138-45
Effect of the novel radiant zone drying method on anthocyanins and phenolics of three blueberry liquids.
The Radiant Zone dryer (RZD) is a novel drying method designed to dry liquid food products into powders. The impact of RZD on the phytochemical content of three blueberry liquid products (extract, juice, and puree) was examined. Comparative analysis between liquid and dried products revealed no statistically significant changes in the total anthocyanins (extract liquid/powder, 11.7/11.2 mg/g of dry weight; juice liquid/powder, 2.7/2.5 mg/g of dry weight; puree liquid/powder, 1.7/1.6 mg/g of dry weight, quantified as cyanidin 3-glucoside equivalents) and total phenolics (extract liquid/powder, 97.1/113.1 mg/g of dry weight; juice liquid/powder, 16.6/17.4 mg/g of dry weight; puree liquid/powder, 8.3/6.2 mg/g of dry weight, quantified as gallic acid equivalents). Total antioxidant activity also showed no significant variation between wet and dried products. The high-performance liquid chromatography-diode array detector (HPLC-DAD) analysis of the products exhibited a similar profile of 13 glycosylated anthocyanins. This study demonstrates that the novel RZD produces high-quality products because the retention of anthocyanins and phenolics during dehydration using RZD is the same as that for freeze drying. The RZD method of operation and its advantages over other dryers is also discussed.
J Agric Food Chem.2010 Jan 13;58(1):324-30
Purified berry anthocyanins but not whole berries normalize lipid parameters in mice fed an obesogenic high fat diet.
Male C57BL/6 mice received diets with either 10% of kcal from fat, or a high fat diet [45% (HF45) or 60% (HF60) kcal from fat]. Diets were prepared with or without freeze-dried powders (10%) from whole blueberries (BB), strawberries (SB), Concord grape or black raspberry. In the 2nd study, purified anthocyanins (ACNs) from SB or BB were added to the drinking water of the treatments fed the HF60 diet. In Study 1, serum triglycerides were increased by feeding the HF45 diet but were elevated further when black raspberry or BB was included in the HF45 diet. Liver total lipids and triglycerides were increased in mice fed HF45 diet and inclusion of any of the berry powders in the HF45 diet did not alter concentrations compared to HF45 controls. In the 2nd study, mice fed the HF60 diet plus purified ACNs from BB in the water had lower body weight gains and body fat than the HF60 fed. Serum cholesterol and triglyceride levels were elevated with the HF60 diet and decreased to control levels when ACNs from either SB or BB were included in the drinking water. Serum leptin levels were consistently decreased to control low fat levels in those ACN treatments in which measures of body fat were decreased. Administering purified ACNs from BB and strawberry via drinking water prevented the development of dyslipidemia and obesity in mice, but feeding diets containing whole berries or purple corn (PC) ACNs did not alter the development of obesity.
Mol Nutr Food Res. 2009 Nov;53(11):1406-18
Strawberry anthocyanin and its association with postprandial inflammation and insulin.
The present study investigates the effect of strawberry antioxidants in beverage form on meal-induced postprandial inflammatory and insulin responses in human subjects. Overweight adults (n 24) consumed a high-carbohydrate, moderate-fat meal (HCFM) accompanied by either a strawberry or a placebo beverage in a cross-over design. Postprandial changes in plasma anthocyanins, their metabolites, insulin, glucose and inflammatory markers were assessed for 6 h. The postprandial concentrations of pelargonidin sulfate and pelargonidin-3-O-glucoside were significantly increased when the strawberry beverage was consumed concurrently with the HCFM compared with the placebo beverage (P < 0·001). The strawberry beverage significantly attenuated the postprandial inflammatory response as measured by high-sensitivity C-reactive protein and IL-6 (P < 0·05) induced by the HCFM. It was also associated with a reduction in postprandial insulin response (P < 0·05). Collectively, these data provide evidence for favourable effects of strawberry antioxidants on postprandial inflammation and insulin sensitivity.
Br J Nutr.2011 Sep;106(6):913-22