Effect of dehydroleucodine in experimental colitis in rats and mice

Dehydroleucodine (DhL), a sesquiterpene lactone (SQL) of the guaianolide ty pe isolated from Artemisia douglasiana Besser, shows a pharmacological cyto protective effect and significantly prevents the formation of gastric and d uodenal lesions induced by various necrotising agents in rodents. The effec ts of DhL, on two models of experimental colitis were examined. Colitis was produced in male Wistar rats by rectal instillation of 5 and 10% acetic ac id, following the methods of Eliakim et al. and Le Duc et al., respectively . In mice colitis was produced by rectal instillation of 0.1 ml of 2,4,6-tr initrobenzene sulphonic acid (5 mg in 50% ethanol) (TNB) as previously desc ribed by Chin et al. In this study, the administration of DhL 40 mg kg(-1) (1 h before the induction of colitis) significantly decreased mucosal damag e. This effect was consistent in both models. The protection provided by Dh L was accompanied by significant decreases in diarrhoea and colon weight; a nd histologically normal mucosa without ulceration and mucus production wer e observed. This study shows that both TNB and acetic acid colitis can be p harmacologically controlled by DhL. Our results suggest that the protective activity of DhL in experimental colitis is mediated, at least in part, thr ough the increase of glycoprotein synthesis, anti-inflammatory effect and i nhibition of COX-2 induction, and by inhibiting the degranulation of cells containing monoamines. (C) 1999 Academic Press.