Bacterial mutagenicity of eight medicinal herbs from Zimbabwe

Eight plants traditionally used as medicines in Zimbabwe were evaluated for mutagenicity. The required plant parts were dried, powdered and extracted in a Soxhlet apparatus with distilled water. The extracts were tested using Salmonella typhimurium strains TA97a, TA98, TA100 and TA102. The results indicate five of these extracts are nonmutagenic in the assay while three of the extracts were found to be mutagenic. The three plant extracts, namely those of Combretum erythrophyllum, Gnidia kraussiana and Barlerii randii, were found to be mutagenic to strain TA102. Furthermore, the extract of C. erythrophyllum was also mutagenic to strain TA100. The presence of S9 mix appeared to diminish the mutagenicity of the extracts except in the case of C. erythrophyllum, the mutagenicity of which was enhanced in strain TA100. These results assume importance in view of the fact that these plants are used as therapeutic agents.