Study on Antioxidant Activities of Five Common Vegetable Spices

The total phenolic contents of the extracts from five vegetable spices with 4 different polar solvents were determined by Folin-Ciocalteu's phenol method. The free radical scavenging activities of the extracts were assayed by 1,1-diphenyl-2-picrylhydazyl(DPPH). The total reducing powers of the extracts were tested with ferric reducing antioxidant power (FRAP). The inhibition effects of the extracts on lipid peroxidation of rat liver microsomes induced by Fe2+ -cysteine were detected with thiobarbituric acid (TBA). The results showed that methanol extract of Eugenia caryophylata showed the highest total phenolic content and the strongest antioxidant activity among all extracts. The total phenolic content, concentration of 50% DPPH· scavenging, total reducing power, and concentration of 50% inhibition of rat liver microsomes lipid peroxidation induced by Fe2+ -cysteine were 724.58±9.58 mg/g,1.476μg/ml, 6079.64±105.4μmol/g and 20.48μg/ml respectively. Generally, the total phenolic contents of the extracts with high polar solvents are higher than those of extracts with low polar solvents, and the antioxidant activities are stronger than those of extracts with low polar solvents.