Purpose: To explore the antioxidant properties of the methanol extract of
Pericarpium Zanthoxyli
and its effect on inducible nitric oxide synthase (iNOS), cycleooxygenase-2 (COX-2) and lipopolysaccharides (LPS)-induced cell damage in macrophage cells.
Methods: Anti-oxidant activities were tested by measuring free radical scavenging activity (DPPH, NO) and lipid peroxidation levels. The mechanism of anti-oxidant action of
Pericarpium Zanthoxyli extract was determined by Western blot analysis for iNOS and COX-2 expression in LPS-stimulated RAW 264.7 cells.
Results: Pericarpium Zanthoxyli extract contained anti-oxidant components including phenolics (2.456 mg/g), flavonoids (0.127 mg/g) and anthocyanins (20.34 mg/g). The extract exerted significant radical scavenging activity in a dose-dependent manner. It also inhibited lipid peroxidation and exerted dramatic reducing power (28.9-fold compared with control at a concentration of 1 mg/ml). Production of iNOS induced by LPS was significantly (p < 0.05) inhibited by the extract, suggesting that the extract inhibits nitric oxide (NO) production by suppressing iNOS expression. Strikingly, COX-2 induced by LPS was also significantly (p < 0.05) inhibited by the extract.
Conclusion: These results suggest that the methanol extract of
Pericarpium Zanthoxyli exerts significant anti-oxidant activity via inhibiting free radicals, iNOS and lipid peroxidation as well as by inhibition of COX-2 enzyme.
