Studies of Piper auritum Kuntz's Mutagenic and Antimutagenic Properties Using the Ames Test.

BACKGROUND: Piper auritum Kuntz is an endemic plant from Mexico and Central America, where it is called "hoja santa", and it is widely used in both local cuisine and traditional medicine. By using the Ames test (strain TA98), we recently demonstrated that ethanol extract from the plant has no mutagenic potential and that it has a significant antimutagenic effect. OBJECTIVES/METHODS: In the present report, we extended this evaluation by using five strains of the Salmonella/microsome mutagenicity assay. Moreover, we evaluated the mutagenic/antimutagenic potential of the major component of the ethanol extract, safrole, with the TA98 strain and employed docking studies to examine the molecular relationship of safrole with the CYP1A1 isoform. RESULTS: Our results confirmed the absence of mutagenicity in the ethanol plant extract, as well as a concentration-dependent inhibitory effect on the damage induced by benzo[a]pyrene (BaP). With respect to safrole, we also determined that the compound has no mutagenic potential and has a strong inhibitory effect on the damage induced by BaP. Docking and kinetic analysis confirmed the coupling of safrole with the active site of the CYP1A1 enzyme, leading to competitive inhibition. CONCLUSIONS: These results suggest that the inhibitory effect on the enzyme activity is one of the possible antimutagenic mechanisms.