Evaluation of antigenotoxic activity of isoliquiritin apioside from Glycyrrhiza glabra L.

Prevention of manifestation of events characteristic of carcinogenesis is being emphasized a rational strategy to combat cancer. Reactive oxygen species (ROS) play an important role in tumor initiation through oxidative damage of DNA. In search for lead molecules in cancer chemoprevention from natural products, a fraction 'Rlicca' isolated from Glycyrrhiza glabra was studied for modulatory effect against hydrogen peroxide and 4-nitroquinoline-N-oxide induced genotoxicity in Escherichiacoli PQ37 using SOS chromotest and in human peripheral blood lymphocytes using the Comet assay. The fraction 'Rlicca' at a concentration of 191 microM decreased the SOS inducing potency (SOSIP) of hydrogen peroxide (1.0mM) and NQO (20 microg/ml) by 83.72% and 68.77%, respectively. In the human blood lymphocytes, 'Rlicca' reduced the tail moment induced by hydrogen peroxide (25 microM) and NQO (5 microg/ml) by 88.04% and 76.64%, respectively, using the Comet assay. The spectroscopic data of 'Rlicca' fraction revealed it to be isoliquiritin apioside, a chalcone oligoglycoside. This is the first report of isoliquiritin apioside with marked potential to combat oxidative stress-induced genotoxicity.