Abstract

Soo-Hwan Lim, Sung Ho Choi, Yun Im Oh and Sung-Jin Kim*

We tested to determine if Corni fructus extract has antioxidant activities and explored its potential mechanism in terms of iNOS and COX-II involvement. Anti-oxidative actions were explored by measuring free radical (NO, DPPH) scavenging activity, and TBARS levels. The mechanism of antioxidative action of Corni fructus extract was determined by performing Western blot analysis for iNOS and COX-II expression in lipopolysaccharide (LPS) stimulated Raw cells. 70% methanolic extract of Corni fructus exerted significant DPPH free radical scavenging activity in a dose-dependent manner. The DPPH-free radical scavenging activity was stronger than that of vitamin E. It also markedly inhibited TBARS formation. Strikingly, the Corni fructus extract has dramatic reducing power with maximal activity observed as 231-fold over control. Production of iNOS induced by LPS was significantly inhibited by the Corni fructus extract, suggesting it inhibits NO production by suppressing iNOS expression. However, COX-2 induced by LPS was not significantly altered by the Corni fructus extract. The Corni fructus extract contains anti-oxidant components including phenolics, flavonoids and anthocyanin at the concentration of 18.07, 2.31 and 7.83 mg/g, respectively. The subsequent chloroform fraction enriched with flavonoids almost completely blocked the iNOS induction and NO production caused by LPS in the Raw cells.