Modulatory effects of Thymbra spicata L. different extracts against the mercury induced genotoxicity in human lymphocytes in vitro

Mercury, a xenobiotic metal, is a highly deleterious environmental pollutant. Moreover, in any form mercury is reported to be toxic. On the other hand, Thymbra spicata L. , a member of the Lamiaceae family, has long been investigated popularly of biological roles; mainly antimicrobial and antioxidant activities. However, there are very scarce data on the cytogenetic effects of thyme species. The purpose of this study was to investigate the genetic safety of different extracts from T. spicata (water extract, methanol extract, and ethanol extract) and the effects of T. spicata on mercury (as HgCl 2 ) induced genotoxicity. Sister chromatid exchange (SCE) and micronucleus (MN) assays were performed to assess DNA damages in cultured human lymphocytes (n = 5). Our results clearly revealed that, the SCE and MN rates induced by HgCl 2 were alleviated by the presence of T. spicata . As conclusion, this study demonstrated for the first time that the T. spicata provided increased resistance of DNA against HgCl 2 induced genetic damage in human lymphocytes. Based on the results of this study, it may be concluded that the T. spicata is a nontoxic material that could be used as a suppressor of heavy metal-induced genotoxicity.