Polyphenols contents and antioxidant capacity of 68 Chinese herbals suitable for medical or food uses

The present study estimated in vitro antioxidant activities of 68 common Chinese herbals both for medical and food uses, using Folin–Ciocalteu, ferric-reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. The results showed different extraction had various antioxidant properties. Six plant materials including Chinese White Olive, Clove, Pricklyash Peel, Villous Amomum Fruit, Chinese Star Anise and Pagodatree Flower appeared highest total phenolics (>45 mg gallic acid equivalents (GAE)/g) and flavonoids content (>45 mg rutin equivalents (RE)/g), which also showed highest antioxidant activity (FRAP value > 2.5 mmol/g, DPPH radical-scavenging capacity > 85%), indicating they have potentials for use as natural sources of antioxidant foods. The total phenolics content of these 68 plant extracts was significantly positively correlated (r2 = 0.9467) with their antioxidant capacity. Therefore, the content of phenolic compounds could be used as an important indicator of its antioxidant capacity.