Swapna Maity, Joseph Rajan Vedasiromoni and Dilip Kumar Ganguly (*)
Division of Pharmacology and Experimental Therapeutics, Indian Institute
of Chemical Biology, 4 Raja S. C. Mullick Road, Calcutta 700032, India
(*) To whom correspondence should be addressed.
Abstract: The role of a hot water extract of black tea (Camellia
sinensis (L). O. Kuntze Theaceae) in the gastric cytoprotective mechanisms
was studied using gastric mucosal lesions produced by various ulcerogens
in rats as an experimental model. Prior oral administration of black tea
extract (BTE) at 20 ml/kg, i.g. once a day for 7 days significantly reduced
the incidence of gastric erosions and severity induced by ethanol, diethyldithiocarbamate
(DDC) and diethylmaleate (DEM). This treatment also favorably altered the
changes in acid and peptic activity of gastric juice in these ulcerogen-treated
animals. Singular administration of succimer (60 mg/kg, i.g.), the standard
sulfhydryl containing antiulcer drug used as a reference drug, was also
effective. The levels of glutathione and glutathione peroxidase were significantly
decreased after treatment with ethanol, DDC and DEM, and this decrease was
prevented by BTE pretreatment in the aforesaid manner. Other major features
of BTE-induced reversal of ulcerogenic agents include a significant decrease
in the protein content and a marked increase in hexosamine and sialic acid
content. These results suggest a major role for glutathione, an endogenous
antioxidant, in the cytoprotection against ulceration afforded by BTE.
Keywords: Camellia sinensis, Reduced glutathione, Gastric ulcer, Ulcerogen,
Cytoprotection