Protective effects of two astragalus species on ulcerative colitis in rats

Purpose: To investigate the anti-inflammatory activities of root extracts of Astragalus gummifera and Astragalus kurdicus, as well as their protective effects against acetic acid-induced ulcerative colitis (UC) in rats. Methods: The roots of both species were shade-dried, pulverized to fine powder and extracted with 80% ethanol. The extracts were lyophilized using freeze-dryer, and their anti-inflammatory effects were evaluated in rats by carrageenan-induced paw edema. In UC study, the extracts, at doses of 200 and 400 mg/kg, were given orally to rats for 5 days, with the last dose given 2 h prior to colitis induction. Histopathological studies were carried out on the colon tissues. Dexamethasone (DEX) was used as standard anti-inflammatory drug. Results: A. gummifera (400 mg/kg) and A. kurdicus (200 and 400 mg/kg) significantly reduced carrageenan-induced edema, offered protection against UC and arrested UC-induced increases in myeloperoxidase (MPO) activity. Histological examination of colon sections also revealed evidence of extract-induced protection from UC. Conclusion: These results suggest that A. gummifera and A. kurdicus root extracts have promising potential as sources of anti-inflammatory agents which may be useful in the treatment of UC.