Anti-ulcer effect of tea catechin in rats.
Oral administration of tea catechin dose-dependently prevented absolute ethanol-induced (50, 100, 200 mg/kg) or restraint plus water immersion stress-induced acute gastric mucosal injury (300, 400 mg/kg) in rats. When the effect of test compound was evaluated on the 15th day after acetic acid injection to rats, repeated oral administration of tea catechin (25, 50, 100 mg/kg twice daily) dose-dependently accelerated the healing of acetic acid-induced chronic gastric ulcers. Tea catechin (10(-5)-10(-1) g/100 ml) concentration-dependently scavenged superoxide anions in vitro. Tea catechin (100, 200 mg/kg orally) markedly inhibited the increase in thiobarbituric acid-reactive substances in the injured mucosa of rats treated with 50% ethanol. Tea catechin (50, 100 mg/kg twice orally, daily) markedly inhibited the increase in content of thiobarbituric acid-reactive substances in the ulcerated region of acetic acid-induced gastric ulcers on the 7th and 15th days. In addition, at 50, 100 and 200 mg/kg orally, it dose-dependently prevented the decrease in gastric mucosal hexosamine content induced by absolute ethanol, although it failed to inhibit the basal gastric acid secretion. These results suggest that tea catechin may primarily protect gastric mucosa from acute gastric mucosal injury and promote the healing of chronic gastric ulcers by its antioxidant activity and gastric mucus-increasing actions.
Hamaishi
Kanoko
K
Laboratory of Analytical Pharmacology, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
Kojima
Ryoji
R
Ito
Mikio
M
D019342:Acetic Acid / Q000008:administration & dosage / Q000633:toxicity; D000284:Administration, Oral; D000818:Animals; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity; D016166:Free Radical Scavengers / Q000037:antagonists & inhibitors / Q000378:metabolism; D005744:Gastric Acid / Q000378:metabolism; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006595:Hexosamines / Q000378:metabolism; D007101:Immersion / Q000009:adverse effects; D008297:Male; D015394:Molecular Structure; D009853:Omeprazole / Q000008:administration & dosage / Q000627:therapeutic use; D008517:Phytotherapy / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D012149:Restraint, Physical / Q000009:adverse effects / Q000379:methods; D013276:Stomach Ulcer / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D013392:Sucralfate / Q000008:administration & dosage / Q000627:therapeutic use; D013662:Tea / Q000737:chemistry*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000897:Anti-Ulcer Agents; D016166:Free Radical Scavengers; D006595:Hexosamines; D017382:Reactive Oxygen Species; D013662:Tea; D017392:Thiobarbituric Acid Reactive Substances; D000431:Ethanol; D013392:Sucralfate; D002392:Catechin; D009853:Omeprazole; D019342:Acetic Acid