Improvement of lymphocyte resistance against H2O2-induced DNA damage in Sprague-Dawley rats after eight weeks of a wild blueberry (Vaccinium angustifolium)-enriched diet

The effect of wild-blueberry consumption on the resistance of H2O2-induced DNA damage was evaluated in the Sprague-Dawley (SD) rat. Thirty-two, four week-old SD rats were randomly assigned to two groups of sixteen rats each and fed a control diet (C) or a wild-blueberry (WB) diet for four or eight weeks. Following the dietary treatment, plasma antioxidant capacity was assessed by the TRAP assay. Ex vivo protection from H2O2-induced DNA damage was evaluated in lymphocytes by means of the comet assay. No significant effect was detected in plasma antioxidant capacity at four and eight weeks in both dietary groups. In contrast, the level of DNA damage was significantly lower in rats fed the WB diet compared with those on the C diet after eight weeks (11.2 +/- 1.0% vs 17.2 +/- 2.4% DNA in tail, p <= 0.05) but not after four weeks. In conclusion, while WB consumption did not affect plasma antioxidant activity, it improved lymphocyte protection against oxidative damage, but only after eight weeks. (C) 2010 Elsevier B.V. All rights reserved.