Anti-inflammatory activity of Sri Lankan black tea (Camellia sinensis L.) in rats

This study examined the anti-inflammatory potential of Sri Lankan black tea (Camellia sinensis L. Family: Theaceae) using both acute (carrageenan-induced paw oedema) and chronic (formaldehyde-induced paw oedema and cotton pellet granuloma test) rat inflammatory models. Three dose of black tea brew (BTB) [84 mg/ml, equivalent to 1.5 cups; 168 mg/ml, equivalent to 3 cups; and 501 mg/ml, equivalent to 9 cups] were made using high grown unblend Dust grade No: 1 black tea samples and was orally administed to rats (n = 6-9/ dose/ test). The results showed that Sri Lankan BTB possesses marked and significant (P < 0.05) oral anti-inflammatory activity against both acute and chronic inflammation. This anti-inflammatory activity was dose-dependent in the carrageenan-induced paw oedema test and cotton pellet granuloma test. Further, in the carrageenan paw oedema model, the anti-inflammatory activity of BTB was almost identical to green tea brew of both Chinese and Japanese types. Further, the BTB had significant antihistamine activity (in terms of wheal test) phagocytic cell migration inhibitory activity (in terms carrageenan-induced leucocyte peritoneal infiltration test), nitric oxide production inhibitory activity, antioxidant activity (DPPH method) and prostaglandin synthesis inhibition activity (in terms of rat enteropooling test). It is concluded that Sri Lankan black tea has marked anti-inflammatory potential against both acute and chronic inflammation which is mediated via multiple mechanisms.