An herbal medicine orengedokuto prevents indomethacin-induced enteropathy

Prostaglandin E2 (PGE2) is a key regulator of gastrointestinal, immunological, and mucosal homeostasis. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the prostaglandin-producing enzyme cyclooxygenases (COXs), and can induce serious complications, such as gastrointestinal damage, with long-term treatment. Orengedokuto (OGT), a Japanese traditional herbal medicine (Kampo medicine), is effective in various animal models of enteropathy. In the present study we examined whether OGT prevents enteropathy induced by NSAIDs in mice. Ulceration in the small intestine was induced with 2 subcutaneous injections of indomethacin (20 mg/kg body weight). Orally administered OGT prevented or reduced lethality, intestinal lesions, bleeding, increased serum nitrate/nitrite levels, and reduction of mucosal PGE2 induced by indomethacin. These beneficial effects of OGT were accompanied by increased production of PGE2 and interleukin 10 by isolated lamina propria mononuclear cells; COX-2 in these cells may be a major source of PGE2 in normal intestines. These findings suggest that OGT could be an effective therapeutic agent for the treatment of inflammatory bowel disease and adverse reactions to NSAIDs.