Anti-inflammatory effect of oolong tea polyphenols

The anti-inflammatory activity of aqueous oolong tea extract was tested. The formation of edema caused in rats paws by injection of carrageenin was effectively depressed by soaking the rat paws in hot oolong tea extract. It gives 60% inhibition at the dose of 75 ppm of oolong tea extract. Oolong tea extract showed higher anti-inflammatory activity than those of green and black tea extracts. The active components were found to be catechins and oolong tea tannin (oxidative products of catechin in oolong tea) fractionated from aqueous oolong tea extract. By oral administration of oolong tea extract, carrageenin-induced inflammation was also inhibited, but the anti-inflammatory avtivity by oral administration was lower than by the soaking treatment. The inflammatory activity of percutaneous absorbed oolong tea polyphenols was assumed to be due, at least partly, to the inhibition of prostaglandin biosynthesis in rat tissue injected with carrageenin.