The Effect of Anthocyanin-Rich Wild Blueberry (V. angustifolium)Consumption on Lymphocyte Protection Against H2O2-Induced DNA Damage in an Animal Model

Fruits and vegetables contain a wide variety of phytochemicals, such as anthocyanins which have been demonstrated to have a significant antioxidant activity and multiple beneficial effects on the health of animals and humans (1). However, the mechanism by which anthocyanins are absorbed is unclear; several animal studies have documented that anthocyanins are absorbed mainly in their intact glycosidic form and rapidly reach (15 min–2 h) the circulatory system, where they can exert their effects on the target tissues (2, 3). It is well documented that blueberries and other berries have a high antioxidant capacity. In vitro studies have shown that blueberry anthocyanins have the capacity to reduce H2O2-induced reactive oxygen species in endothelial and red blood cells. Researchers have documented a significantly enhanced red blood cell resistance to H2O2 (100μM) after incubation with anthocyanins in vitro (4). Furthermore, supplementation of rats with isolated blueberry anthocyanins reduced red blood cell susceptibility to free radical damage and decreased liver DNA damage (5). The objectives of our study were to examine the effect of wild blueberry (V. angustifolium) consumption (8 weeks) on anthocyanin concentration and distribution in blood, urine, feces, brain and liver and to evaluate lymphocyte DNA resistance against oxidative damage induced ex-vivo by H2O2 in Sprague-Dawley (SD) rats. Sixteen, 5 week-old SD rats were fed a control (C) or a wild blueberry (WB: 8%) diet for 8 weeks. Anthocyanin (ACN) profiles in urine and feces were analyzed by LCMS/ MS. Ex vivo protection from H2O2-induced DNA damage (500 μmol/L) was evaluated in lymphocytes by the comet assay. No significant differences were detected in body and liver weights between the WB and C diet groups. After 8 weeks on the WB diet, ACN concentration in feces and urine was 25.9 ± 9.2μg/g and 127.6 ± 46.3ng/ml respectively, while only traces were detected in plasma. No ACNs were found in rats fed the C diet. Metabolites of ACNs (i.e. benzoic and hippuric acids) were present in urine, feces, brain and liver of the WB group. Wild blueberry consumption improved lymphocyte protection against oxidative stress. Levels of DNA damage were significantly lower in rats fed the WB diet compared to those on the C diet (11.2 ± 4.1% vs. 17.2 ± 8.0% DNA in tail, p≤0.05). We have documented that wild blueberry ACNs are bioavailable in SD rats fed a WB diet for 8 weeks. Additionally, wild blueberry consumption reduced lymphocyte DNA damage induced by oxidative stress in this animal model. (1) Wang J., et. al., J. Agric. Food Chem. 2002: 50: 850–857. (2) Morazzoni P., Drug Research 1991: 41, 128–131. (3) Matsumoto H., et al., J. Agric. Food Chem. 2001: 49: 1546 –1551. (4) Youdim K A. et al., J. Nutr. Biochem. 2002: 13, 282–288. (5) Dulebohn R., J. Agric. Food Chem. 2008, 56 (24), 11700-11706.