Antimutagenic activity of major fractions of Zataria multiflora Boiss by Ames method

Abstract

Zataria multiflora is a medicinal plant that has been interested in antimutagenicity effect because of its high antioxidant activity and richness of flavonoids. Antimutagenicity effect of total extract of the plant has been reported previously. Aerial parts of Z. multiflora were extracted by petroleum ether, chloroform and 80% methanol by liquidâ€liquid extraction method consequently. The fractions were concentrated in vacuum and dried at 40°C in oven. The genotype of two standard strains of Salmonella typhimurium (TA98, TA100) was confirmed by the evaluation of two important factors of histidine requirement and the presence of R factor. The minimum inhibition concentration (MIC) of the fractions against these two
strains was determined by agar dilution method. From each fraction, various concentrations less than MIC were studied
for antiâ€mutagenic test. The sample along with bacterial strain and mutagen agent were incubated at 37°C for 48 h. The number of revertant colonies was counted and compared with control plates. Our results showed that all fractions especially petroleum ether and chloroform ones maintain the number of colonies in the standard range in control plates and prevent from the growth of many strains of bacteria and increase of revertant colonies enhancement in a concentrationâ€dependent manner. This effect was prominent against TA100 starin. Methanolic fraction exhibited antiâ€mutagen activity just in the highest used concentration in the presence of TA98.

Key words: Ames test, antiâ€mutagenicity, fraction, phenylpropanoids, Salmonella typhimurium, Zataria multiflora