Gentiana asclepiadea exerts antioxidant activity and enhances DNA repair of hydrogen peroxide- and silver nanoparticles-induced DNA damage

Exposure to high levels of different environmental pollutants is known to be associated with induction of DNA damage in humans. Thus DNA repair is of great importance in preventing mutations and contributes crucially to the prevention of cancer. In our study we have focused on quantitative analysis of Gentiana asclepiadea aqueous or methanolic extracts obtained from flower and haulm, their antioxidant potency in ABTS post-column derivatisation, and their potential ability to enhance DNA repair in human lymphocytes after hydrogen peroxide (H2O2) treatment (250 mu M, 5 min). We also studied DNA repair in human kidney HEK 293 cells after exposure to 20 nm silver nanoparticles (AgNPs) (100 mu g/ml, 30 min) in the presence and absence of the plant extract. We have found that mangiferin along with unidentified polar compounds are the most pronounced antioxidants in the studied extracts. Extract from haulm exhibited slightly stronger antioxidant properties compared to flower extracts. However, all four extracts showed significant ability to enhance DNA repair in both cell types after H2O2 and AgNP treatments. (c) 2012 Elsevier Ltd. All rights reserved.