Antimutagenic and antioxidant/prooxidant activity of quercetin.

The present study has been performed to evaluate the antimutagenic activity of quercetin, ascorbic acid and their combination against an oxidative mutagen. An effort was also made to correlate this activity to the in vitro antioxidant activity of these agents. Antimutagenicity testing was done in Ames Salmonella Assay system using Salmonella typhimurium TA102 against t-butylhydroperoxide as an oxidative mutagen. In vitro antioxidant scavenging activity was tested for DPPH free radical, superoxide anion, hydrogen peroxide and hydroxyl radical in their specific test systems. Quercetin (0.5-8 nmole/plate) and ascorbic acid (0.1-100 micromole/plate) showed significant effect. Quercetin (4 and 8 nmole/plate) when combined with ascorbic acid (500 nmole/plate) showed an increase in the antimutagenic activity. In vitro antioxidant activity of quercetin was better than ascorbic acid in all the test systems used. The study indicated that the antimutagenic activity of quercetin was not solely accountable by its antioxidant nature. However, in vitro free radical scavenging activity of quercetin correlated well with the antimutagenic activity.