Effect of a novel water-soluble vitamin E derivative as a cure for TNBS-induced colitis in rats.

Lipid peroxidation mediated by oxygen free radicals plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Vitamin E is a lipid-soluble antioxidant and is generally considered to protect against lipid peroxidation of the cell membrane and to scavenge singlet oxygen and superoxide anion radical. Therefore, vitamin E or its derivatives are expected to have particular application for patients suffering from IBD. The aim of this study was to investigate the antioxidative effects of the water-soluble vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetra-methylchroman-6-ol(TMG), on the therapy of experimental colitis in rats. Colitis was induced in male Wistar rats weighing 200 g using an enema of trinitrobenzene sulfonic acid (TNBS) dissolved in 50% ethanol; TMG dissolved in physiological saline was injected intra-peritoneally every day from 24 h after the enema of TNBS. The damage score, wet weight of the colon, and increase in body weight were estimated 1 week after the enema of TNBS. Thiobarbituric acid-reactive substances (TBA-RS), an index of lipid peroxidation, and tissue-associated myeloperoxidase (MPO) activity in the colonic mucosa were measured 1 week after the induction of colitis. As a result, increase in body weight was inhibited by the induction of colitis, although the inhibition was reduced in the group treated with TMG. The damage score, wet weight, TBA-RS and MPO activity were increased significantly in the colitis group; however, they were inhibited by the administration of TMG. These results suggest that TMG is effective for the treatment of colitis in rats induced by TNBS. In the future, TMG could be a new therapeutic agent for IBD.