Stem bark aqueous extracts of eight woody plants Brachychiton populneus, Ceiba pentandra, Bombax malabaricum, Chorisia speciosa, Albizia lebbeck, Bauhinia variegata, Kigelia africana and Pinus halepensis were tested for their mutagenic and antimutagenic potential in the Ames test with Salmonella typhimurium strains TA98 and TA100. The aqueous extracts were neither toxic nor mutagenic in S. typhimurium tester strains. All of the tested extracts showed detectable antimutagenic effect towards the direct acting mutagens 2-nitrofluorene (2-NF) in TA98 as well as sodium azide in TA100. The extract from Kigelia africana was the most effective in reducing the mutagenicity caused by the direct mutagen 2-NF in the TA98 with 85.42% inhibition rate. A. lebbeck stem bark extract demonstrated the highest antimutagenic activity reducing the base substitution mutations rate for strain TA100 by 94.66% in pre-incubation assay. The results obtained showed that the stem bark aqueous extracts tested can protect cells against induced gene mutations.

The antigenotoxic effects of juices of three medicinal plants, Chelidonium majus L., Plantago major L. and Tussilago farfara L. has been studied in two bacterial tests — SOS chromotest and Rec assay. Antigenotoxic effect was determined against known genotoxic substances — nalidixic acid in SOS chromotest and furacilin in Rec assay. Preparations obtained from the leaves of Ch. majus L. exhibited significant antigenotoxic effect in both the SOS chromotest and the Rec assay. It was shown that dilution of the herb juice of T. farfara L resulted in high bioantimutagenic activity in SOS chromotest. P. major L. preparations did not display statistically significant antigenotoxic activity in the both tests used. Possible mechanisms of antigenotoxic effects of Ch. majus L. and T. farfara L. plants obtained are discussed.