MUCUS SYNTHESIS AND SULFHYDRYL-GROUPS IN CYTOPROTECTION MEDIATED BY DEHYDROLEUCODINE, A SESQUITERPENE LACTONE

The aerial parts of Artemisia douglasiana have been used in folk medicine as a cytoprotective agent against the development of peptic ulcer. Dehydroleucodine [1], its active principle, significantly prevents the formation of gastric lesions induced by the exposure of the rats to absolute EtOH. It was found in this study that (a) pretreatment of rats with 1 (40 mg/kg, po) caused a significant increase in glycoprotein synthetic activity, approximately sevenfold as large as that of the control; and (b) pretreatment of the rats with the thiol reagent N-methylmaleimide (NEM) significantly diminished the cytoprotection provided by 1. However, the protective effect of 1 was not totally abolished by pretreatment with a combination of indomethacin and NEM, indicating additional mechanisms are involved in the cytoprotective action of 1.