Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 by methanolic extract of crataegi fructus

Crataegi Fructus has a wide variety of pharmacological actions such as improving digestion, cardiotonic action, and hypolipodemic effect. In the present study, we sought to test whether the Crataegi Fructus extract has antioxidant activities. Anti-oxidative actions were explored by measuring free radical scavenging activity, nitric oxide (NO) levels, and reducing power. The mechanism of anti-oxidative action of Crataegi Fructus was explored by measuring inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) induction in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Seventy percent methanolic extract of Crataegi Fructus exerted significant 1,1diphenyl-2-picrylhydrazyl (DPPH) free radicals and NO scavenging activities. More strikingly, the Crataegi Fructus extract exerted dramatic reducing power activity. Expression of iNOS induced by LPS was significantly inhibited by the Crataegi Fructus extract, suggesting that it inhibits NO production by suppressing iNOS expression. Moreover, COX-2 induced by LPS was also markedly inhibited by the Crataegi Fructus extract. These results suggest that 70% methanolic extract of Crataegi Fructus exerts significant antioxidant and anti-inflammatory activities, possibly via inhibiting iNOS and COX-2 induction.