Assessment of Mutagenic Potential of Selected Herbal Teas Sold in Lagos Markets Using the Ames Salmonella Mutagenicity Test

The rapid proliferation of commercially packaged herbal teas in Lagos markets, South West Nigeria, has raised questions about their genotoxic safety, particularly for products lacking rigorous pre-market evaluation. This study assesses the mutagenic potential of five widely sold herbal tea products collected from Balogun and Idumota markets in Lagos using the Ames Salmonella typhimurium reverse mutation assay. Products included preparations based on Hibiscus sabdariffa, Zingiber officinale, Camellia sinensis, Moringa oleifera, and a polyherbal blend. Salmonella typhimurium strains TA98 and TA100 were used with and without S9 metabolic activation fractions. Positive controls included sodium azide (TA100) and 2-nitrofluorene (TA98). Each product was tested at five dose levels in triplicate. None of the five herbal tea products induced statistically significant increases in revertant colony counts above baseline at any dose level in either strain, with or without S9 activation. The mutagenicity ratio remained below 2.0 for all test samples, satisfying the threshold for non-mutagenicity. These findings suggest that the five tested products do not pose direct DNA mutagenic risks under the conditions of the Ames test. The study nonetheless recommends systematic genotoxicity screening as part of routine herbal product regulatory assessment in Nigeria. Keywords: Ames test, mutagenicity, herbal teas, Lagos, genotoxicity