Evaluation of the mutagenic and antimutagenic effects of South African plants.

Dichloromethane and 90% methanol extracts of 42 South African plants were screened for mutagenicity and antimutagenicity using the Salmonella/microsome mutagenicity assay (Ames) against Salmonella typhimurium TA98 and TA100 bacterial strains in the presence and absence of metabolic activator S9. The methanol extracts from whole plants of Helichrysum simillimum, Helichrysum herbaceum and Helichrysum rugulosum indicated mutagenicity. These are the first reported tests on the mutagenicity of Helichrysum species. Six species indicated antimutagenic properties, all in the presence of S9: methanol leaf extract of Bauhinia galpinii, and dichloromethane leaf extracts of Bauhinia galpinii, Clerodendrum myricoides, Datura stramonium, Buddleja saligna, Millettia sutherlandii and Sutherlandia frutescens.