Modulating effect of tanshinones on mutagenic activity of Trp-P-1 and benzo[a]pyrene in Salmonella typhimurium.

The modulating effects of the Chinese medicinal plant 'Tan-shen', the radix of Salvia miltiorrhiza Bunge, on the mutagenic activities of Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole) and B(a)P (benzo[a]pyrene) were investigated using Salmonella typhimurium TA98. Ether- and hot water-extracted 'Tan-shen' enhanced both mutagens at low concentrations, but suppressed them at high concentrations. Extracts by ether treatment were more effective than those extracted by hot water. Dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone IIA were isolated from the ether extract by high performance liquid chromatography (HPLC) and were recognized to be the mutagenic modulators. 4 tanshinones enhanced the mutagenicity of Trp-P-1 by 8-24-fold at 20 micrograms/plate and the enhancement was reduced at the higher concentration. Dihydrotanshinone I suppressed Trp-P-1 activity completely at 100 micrograms/plate.