Antioxidant Activity of Glycyrrhiza cultivar Extracts

Antioxidants are involved in the defense mechanism against the attack of free radicals. This study was carried out to determine the antioxidant activity of new variety of Glycyrrhiza cultivar radix, Wongam and Sinwongam. Dissolved freeze dried Wongam and Sinwongam extracts were filtered by $0.2{\mu}m$ filter and serially diluted at the concentrations of $10{\mu}g/mL$, $50{\mu}g/mL$, $100{\mu}g/mL$, $500{\mu}g/mL$, and $1000{\mu}g/mL$. The antioxidant potential was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, ABTS (2,2-azino-bis (3-rthylbenzthiazoline-6-sulfonic acid) diammonium salt) radical cation decolorization assay, nitrite radical scavenging assay, and ferric reducing antioxidant power (FRAP) assay. DPPH radical scavenging activities (i.e. the highest value $50.9{\pm}0.8%$ by Wongam and $82.6{\pm}1.1%$ by Sinwongam), ABTS radical scavenging activities (i.e. the highest value $88.1{\pm}1.8%$ by Wongam and $98.6{\pm}0.1%$ by Sinwongam), and nitrite radical scavenging activities (i.e. the highest value $87.3{\pm}1.6%$ by Wongam and $89.8{\pm}0.8%$ by Sinwongam) increased in a dose-dependent manner. In addition, ferric reducing power activities also increased in a dose-dependent manner. The FRAP value of Wongam and Sinwongam extracts were $0.72{\pm}0.03$ and $0.99{\pm}0.06$ compared to ascorbic acid, as a positive control, was $1.32{\pm}0.02$. These results suggested that Wongam and Sinwongam have beneficial effects as a potent antioxidant.