thromboxane-b2 and Ulcer

D-002 is an anti-ulcerogenic product, isolated from beeswax, which consists of a well-defined mixture of higher primary aliphatic alcohols. It is highly effective against ethanol-induced ulcers. This study was designed to determine if D-002 shows cytoprotective properties on gastric mucosa in ethanol-induced ulcers. The involvement of endogenous prostaglandins in the protective effect of D-002 was also investigated. When a subulcerogenic dose of indomethacin (10 mg kg-1) was injected simultaneously with oral administration of ethanol, oral pre-treatment with D-002 (5-100 mg kg-1) partially inhibited the gastric protection. D-002 (5 and 25 mg kg-1) administered to normal rats significantly increased the soluble mucus content and also prevented its reduction in rats with ethanol-induced ulcers. In addition, D-002 administered at 5 and 25 mg kg-1 prevented the increase of vascular permeability induced by ethanol (60%) and reduced the concentration of thromboxane B2 (TXB2) in gastric mucosa of rats with ethanol-induced ulcers. These results support the hypothesis that the anti-ulcerogenic properties of D-002 could be related to a cytoprotective mechanism.

Topics: Animals; Anti-Ulcer Agents; Bees; Capillary Permeability; Ethanol; Fatty Alcohols; Female; Gastric Mucosa; Mucus; Prostaglandins; Rats; Rats, Sprague-Dawley; Thromboxane B2; Ulcer; Waxes

The effect of highly purified eicosapentaenoic acid ethyl ester (EPA-E) on colitis was investigated using a guinea pig model. The technique for preparing a degraded carrageenan with a molecular weight of about 30,000 from commercial iota-carrageenan was first refined. When this degraded carrageenan was fed to guinea pigs, localized ulcerations occurred in the cecum with infiltration of numerous mononuclear phagocytes. Oral administration of 300 mg.kg-1.day-1 of EPA-E for 3 weeks significantly prevented the development of colitis. The amounts of prostaglandin E2, thromboxane B2, and leukotriene B4 released from the cecal mucosa were also measured. The release of prostaglandin E2 and thromboxane B2 was significantly decreased in the animals fed EPA-E compared with those given olive oil or a vehicle alone. In addition, there was a positive correlation between the amounts of these eicosanoids and the degree of ulcer formation. However, there was no difference in the amount of leukotriene B4 among various experimental groups of animals. Furthermore, EPA-E feeding induced a significant decrease in the level of arachidonic acid and a significant increase in that of EPA in peritoneal macrophages. These results suggest that EPA has a prophylactic effect on the development of carrageenan-induced colitis, which may be ascribed in part to reduced eicosanoid production.

Topics: Animals; Body Weight; Carrageenan; Cecal Diseases; Colitis; Dinoprostone; Dose-Response Relationship, Drug; Eicosapentaenoic Acid; Fatty Acids; Guinea Pigs; Leukotriene B4; Macrophages; Male; Occult Blood; Thromboxane B2; Ulcer