Indian medicinal plants as a reservoir of protective phytochemicals.

India is one of the 12 mega diversity countries in the world so it has a vital stake in conservation and sustainable utilization of its biodiversity resources. Plant secondary metabolites have been of interest to man for a long time due to their pharmacological relevance. With this in view, the bark powder of Acacia auriculiformis, A. nilotica, Juglans regia, and the fruit powder of Terminalia bellerica, T. chebula, Emblica officinalis, and a combination drug "Triphala," which are known to be rich in polyphenols, were tested for their antimutagenic activities. Antimutagenic activities of the extracts were estimated by employing the plate incorporation Ames Salmonella histidine reversion assay by using the frame shift mutagen tester strain TA98 and base pair substitution strain TA100 against direct acting mutagens (NPD, sodium azide), and the S9-dependent mutagen 2-aminofluorene(2AF). Acetone extracts of all the plants exhibited significant antimutagenic activities among the other extracts tested, but an acetone extract of Acacia nilotica showed a marked anti-mutagent effect. Furthermore, it was more effective against indirect acting mutagen, 2AF, in both TA98 and TA100 tester strains of Salmonella typhimurium than against the direct acting mutagens. The results indicate that an acetone extract of bark and fruit of the medicinal plants under study harbors constituents with promising antimutagenic/anticarcinogenic potential that could be investigated further. Copyright 2003 Wiley-Liss, Inc.