Mutagenicity tests with gallic and tannic acid in thesalmonella/mammalian microsome assay

Abstract
Gallic acid, tannic acid mixture and a purified fraction of tannic acid were evaluated for possible mutagenlc activity in three strains of Salmonella typhimurium, TA98, TA100, and TA1535. These chemicals were not mutagenic either before or after activation with rat and woodchuck microsomal and cytosolic enzymes. However, tannic acid mixture and tannic acid fraction both gave a significantly (p = 0.05) dose‐related reduction in the number of the revertant colonies, compared to the normal spontaneous rever‐tants with no apparent toxic effects in the background lawn. With an agar diffusion assay, the chemicals exhibited toxic effects at 5000 μg/disc.