The Effect of a Grape Seed Extract on Radiation‐Induced DNA Damage in Human Lymphocytes

Plant‐derived antioxidants due to their phenolic compounds content are reported as potential candidates for reducing the levels of oxidative stress in living organisms. Grape seed extracts are very potent antioxidants and exhibit numerous interesting pharmacologic activities. Hydroethanolic (50/50, v/v) standardized extract was obtained from red grape seed (Vitis vinifera, variety Burgund Mare—BM). The total polyphenols content was evaluated by Folin‐Ciocalteu procedure and expressed as $μEq$ Gallic Acid/ml. The aim of this study was to evaluate the potential antioxidant effects of different concentrations of BM extract against $60Co$ γ‐rays induced DNA damage in human lymphocytes. Samples of human lymphocytes were incubated with BM extract (12.5, 25.0 and $37.5 μEq$ GA/ml, respectively) administered at 30 minutes before in vitro irradiation with γ‐rays (2 Gy). The DNA damage and repair in lymphocytes were evaluated using alkaline comet assay. Using the lesion score, the radiation‐induced DNA damage was found to be significantly different $(p<0.05)$ from control, both in the absence and presence of BM extract (except the lymphocytes treated with $37.5 μEq$ GA/ml BM extract). DNA repair analyzed by incubating the irradiated cells at 37° C and 5% $CO2$ atmosphere for 2 h, indicated a significant difference $(p<0.05)$ in the lymphocytes group treated with $25.0 μEq$ GA/ml BM extract, immediately and two hours after irradiation. These results suggest radioprotective effects after treatment with BM extract in human lymphocytes.