Screening of tea clones for inhibition of PhIP mutagenicity.

Standard black and green tea extracts have been known to inhibit mutagenicity caused by PhIP, in the Salmonella typhimurium TA98 assay containing S9 fraction from the liver of rats induced with alpha-naphthoflavone and phenobarbital. Breeding and selection programs for high yielding tea clones have successfully increased yields in many tea producing areas. Six clonal teas and three seedling teas were obtained from a tea producing area in Southern Africa. Standard black and green teas were used as controls. Dose-dependent inhibition of the bacterial mutagenicity elicited by two concentrations of PhIP was found in the extracts of all the teas tested. This indicates that the clonal teas have not lost their anti-mutagenic properties. Small differences were found amongst the clonal teas in their ability to inhibit mutagenicity. This indicates that it may be possible to enhance this trait in future breeding and selection programs.