Gastric ulcer healing activity of Sri Lankan black tea (Camellia sinensis L.) in rats

This study examined the gastric ulcer healing potential of black tea (Camellia sinensis) using Sri Lankan high grown Dust grade No: 1 black tea in rat acetic acid-induced gastric ulcer model. Three oral doses (84, 167 or 501 mg/ml) of black tea brew (BTB) made according to ISO recommendations were used in the evaluation of gastric ulcer healing activity. The results showed a significant (P < 0.05) and dose-dependent gastric ulcer healing activity (in terms of reduction in gastric ulcer area). This effect had a rapid onset (with in 14 days). The gastric ulcer healing activity of BTB was however inferior (by 9 fold) to omeparazole, the reference drug. BTB displayed in vitro antioxidant activity (using DPPH assay; by 2985-3923 Trolox equivalents ìg/l), and also inhibited in vitro nitric oxide production (3-78 %). In addition, BTB had antihistamine activity (by wheal test; by 33.5%) and increased the gastric pH (from 3.3 to 5.9) and impaired the gastric acid output (by 69%). It is concluded that black tea possessed strong, oral gastric ulcer healing activity which is mediated via multiple mechanisms.