Mutagenicity of extracts of brown and black masheri, pyrolysed products of tobacco using short-term tests.

Black and brown varieties of masheri, which are pyrolysed tobacco products were analysed for their mutagenic potentials using a battery of test systems. Both materials were found to be mutagenic in Salmonella typhimurium strain TA98 with metabolic activation and also in V79 Chinese Hamster cells producing 8-azaguanine resistant mutations. Both varieties were found to induce statistically significant increases in micronuclei formation as compared to those produced in the solvent controls. Both varieties induced structural chromosomal aberrations in bone marrow cells of mice. Our data suggest that masheri is a potent mutagen in a variety of test systems and is likely to have a mutagenic potential vis à vis humans.