Modulation of genotoxicity of oxidative mutagens by glycyrrhizic acid from Glycyrrhiza glabra L.

BACKGROUND: The chemopreventive effects of certain phytoconstituents can be exploited for their use as functional foods, dietary supplements and even as drugs. The natural compounds, acting as anti-genotoxic and free radical scavenging compounds, may serve as potent chemopreventive agents. These can inhibit DNA modulatory activities of mutagens and help preventing pathological processes. OBJECTIVES: Present study on Glycyrrhiza glabra L., a promising medicinal plant, widely used in traditional medicine, focused on the bioassay-guided fractionation of its extracts for the isolation of certain phytochemicals with anti-genotoxic potential against oxidative mutagens. MATERIALS AND METHODS: The methanol extract of Glycyrrhiza glabra rhizomes was subjected to column chromatography, and isolated fraction was evaluated for its anti-genotoxic and antioxidant potential using SOS chromotest, Comet assay, and DPPH radical scavenging assay. RESULTS: GLG fraction, which was characterized as Glycyrrhizic acid, inhibited the genotoxicity of oxidative mutagens viz., H(2)O(2) and 4NQOquite efficiently. In SOS chromotest, using E.coli PQ37 tester strain, it inhibited induction factor induced by H(2)O(2) and 4NQO by 75.54% and 71.69% at the concentration of 121.46 μM,respectively. In Comet assay, it reduced the tail moment induced by H(2)O(2) and 4NQO by 70.21% and 69.04%, respectively, at the same concentration in human blood lymphocytes. The isolated fraction also exhibited DPPH free radical scavenging activity and was able to scavenge 85.95% radicals at a concentration of 120 μM. CONCLUSION: Glycyrrhizic acid is a potential modulator of genotoxins as well as efficient scavenger of free radicals.