Protective efficacy of resveratrol against ROS induced cytotoxic and genotoxic effects in human blood lymphocytes

When human cells are exposed to ionizing radiation, Reactive Oxygen Species (ROS) are generated by radiolysis of water. This indirect method, which accounts for approximately 80% of DNA damages. The aim of the study was to evaluate the protective efficacy of resveratrol (RSV) mediated cytotoxic/genotoxic effect of ROS induced in PBL. Heparinized blood samples were collected from two healthy volunteers (n=2), exposed to various concentrations of RSV for two hours and then exposed to the chemotherapeutic drugs to induce ROS generation. MTT assay and DPPH assays were performed to measure the antioxidant efficacy of RSV. Micronuclei frequency was analysed to evaluate genotoxicity effects. Drug treatment decreased the number of viable cells as indicated by the MTT assay, whereas when treated with RSV it showed an increase in the number of viable cells (p<0.05). In the DPPH assay, the inhibition percentage increased significantly as the RSV concentrations increased. The NDI showed significant decrease when treated with drugs but RSV treated cells upon exposure remained undamaged at large, an increase in the frequency of micronuclei when treated with drugs was found with declined steadily as the concentration of RSV increased. The NDCI showed a decrease in cells treated with drugs along with RSV which was found to be statistically significant (p<0.05). Therefore, the present study indicates that RSV has an antioxidant potential which can quench the ROS activity. The findings suggest that RSV, a natural antioxidant offers protection against ROS and do not exert any genotoxicity in human In future, RSV can be used as a radioprotective supplement to the humans exposed to ionizing radiation to reduce the frequency of DNA damage in normal cells. (author)