ANTIOXIDANT ACTIVITY AND ANTIPROLIFERATIVE ACTION OF METHANOLIC EXTRACT OF LIQUORICE (GLYCYRRHIZA GLABRA) IN HEPG2 CELL LINE

摘要

Objective: To evaluate the in vitro antioxidant activity of liquorice ( Glycyrrhiza glabra) against H 2 O 2 induced oxidative stress in HepG2 cell line. Methods: Antioxidant activity of methanolic extracts of Glycyrrhiza glabra was investigated by measuring total phenolic content using folin-ciocalteu reagent (FCR), free radical scavenging activity by DPPH and ferric reducing antioxidant power (FRAP). The presence of phenolic compounds and flavonoids in the extract was confirmed by Liquid Chromatography-Mass Spectrometry (LC-MS) analysis. Furthermore, the protective effect of methanolic extract of Glycyrrhiza glabra against oxidative stress induced by H 2 O 2 in HepG2 cells was investigated by MTT assay. HepG2 cells were exposed with five different treatments viz. liquorice, H 2 O 2 , ascorbic acid, H 2 O 2 +liquorice and H 2 O 2 +ascorbic acid, to explore the effect of the extract on malondialdehyde (MDA) production, catalase activity, and glutathione reductase levels. Results: The total phenolic content estimated in Glycyrrhiza glabra extract was found to be 241.47 μg per 1000 μg/ml of methanolic extract. It was found that as the concentration of the extract was increased both the free radical scavenging activity and ferric ion reducing power was also found to increase. LC-MS analysis confirmed the presence of eight different phenolic compounds in the methanolic extract which are possibly contributing to the antioxidant activity exhibited by the extract. It was also observed that liquorice treated HepG2 cells showed lower MDA and higher glutathione and catalase levels as compared to only H 2 O 2 treated HepG2 cells where increased MDA production, decreased glutathione reductase and catalase production was observed. Conclusion: Our results thus conclude that, the methanolic extract of Glycyrrhiza glabra can be used as natural supplements in various disease conditions where oxidative stress has been reported.