Effects of Nine Active Ingredients in Chinese Herbal Medicine Sho‐saiko‐to on 2‐(2‐Furyl)‐3‐(5‐nitro‐2‐furyl)acryIamide Mutagenicity

The antimutagenic effects of nine active compounds in the Chinese herbal medicine “sho‐saiko‐to” on mutagenesis induced by a direct‐acting mutagen, 2‐(2‐furyI)‐3‐(5‐nitro‐2‐furyl)acrylamide (AF‐2) were investigated in Salmonella typhimurium, strain TA100. The active compounds examined were classified into two major groups, saponins and flavonoids, the former comprising glycyrrhizin, saikosaponins a, c and d, and ginsenosides Rbl and Rgl, and the latter, baicalin, baicalein and wogonin. Saikosaponin a and ginsenoside Rbl were found to reduce the mutagenicity of AF‐2 significantly when applied post‐AF‐2‐treatment in the Salmonella mutagenicity assay. Ginsenoside Rbl also decreased the mutagenic activity of AF‐2 in a simultaneous treatment protocol. The results indicate that saikosaponin a and ginsenoside Rbl may enhance DNA repair, and ginsenoside Rbl may also have the ability to inactivate the mutagenic activity of AF‐2 directly. On the other hand, saikosaponin d and baicalin showed a slight enhancing effect. None of the compounds, except baicalein, showed any toxic effect on the test strain. These findings may be useful for the development of chemopreventive agents.