Chemical characterization, antioxidant properties and anti-inflammatory activity of Chinese water chestnut extracts

Abstract

Ferulic acid, caffeic acid and p-coumaric acid have been identified in the Eleocharis dulcis (Burm.f.) Trin. ex Hensch. (Chinese water chestnut (CWC)) ethyl acetate extract. The ethyl acetate extract of CWC had the highest DPPH radical scavenging activity (IC50 = 12.81 ± 0.09 μg/ml), which was higher than that of the positive control butyl hydroxy anisd (IC50 = 14.73±0.08 μg/ml). The reducing power of 0.5 mg/ml CWC was 1.21 at 0.5 mg/ml. The ethyl acetate extract significantly attenuated the production of reactive oxygen species in a dosedependent manner. The anti-inflammatory activity of CWC extracts was assessed in lipopolysaccharide-induced RAW 264.7 macrophages. The highest anti-inflammatory activity was conferred by 300 μg/ml CWC ethyl acetate extract, which also significantly reduced nitric oxide production (p < 0.05). Treatment with the CWC ethyl acetate extract downregulated the expression of TNF-α, iNOS, and COX-2 genes. For the first time the identification of phenolic acids from CWC and their correlation with anti-inflammatory activity were reported in this work.