Antioxidant and anti-inflammatory effect of plumieride in dextran sulfate sodium-induced colitis in mice

This study aimed to investigate the potential effect of plumieride, an iridoid glycoside isolated from Alamanda cathartica L. flowers, against dextran sulfate sodium (DSS)-induced colitis in mice. Colitis was induced in female swiss mice by adding DSS 3% to the drinking water. The animals were treated with vehicle (water), 5-aminosalicylic acid (100 mg/kg) or plumieride (10, 30 and 100 mg/kg) once a day, during 7 days. The body weight progression and the disease activity index was evaluated daily. On the eighth day, colons were collected for the measurement of the size, histological, histochemical, biochemical and inflammatory analysis. The cytotoxicity of plumieride on intestinal epithelial cell (IEC-6 cell line) was also evaluated. Plumieride, at dose of 100 mg/kg, significantly attenuated the mice weight loss, showed lower score in the disease activity index, diminished the colon shortening, improved the histological damage and avoided mucosa intestinal mucus depletion when compared with vehicle-treated only group. Moreover, plumieride was able to reduce the amount of colonic lipid hydroperoxides, while augmented reduced glutathione levels and superoxide dismutase activity. Although DSS intake stimulated an increase in myeloperoxidase activity and in tumor necrosis factor content on the colon tissue of the vehicle-treated group, the colons obtained from mice treated with plumieride did not present any of these changes. Taking together, the results of the present study disclose that plumieride exhibited a significant efficacy in attenuating the parameters of experimental ulcerative colitis, which may be mediated by an antioxidant and anti-inflammatory effect.