Anti-inflammatory effects of Mangifera indica L. extract in a model of colitis

To investigate the effect of aqueous extract from Mangifera indica L. (MIE) on dextran sulfate sodium (DSS)-induced colitis in rats. MIE (150 mg/kg) was administered in two different protocols: (1) rectally, over 7 d at the same time as DSS administration; and (2) once daily over 14 d (by oral gavage, 7 d before starting DSS, and rectally for 7 d during DSS administration). General observations of clinical signs were performed. Anti-inflammatory activity of MIE was assessed by myeloperoxidase (MPO) activity. Colonic lipid peroxidation was determined by measuring the levels of thiobarbituric acid reactive substances (TBARS). Reduced glutathione (GSH) levels, expression of inflammatory related mediators [inducible isoforms of nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, respectively] and cytokines [tumor necrosis factor (TNF)-α and TNF receptors 1 and 2] in colonic tissue were also assessed. Interleukin (IL)-6 and TNF-α serum levels were also measured. The results demonstrated that MIE has anti-inflammatory properties by improvement of clinical signs, reduction of ulceration and reduced MPO activity when administered before DSS. In addition, administration of MIE for 14 d resulted in an increase in GSH and reduction of TBARS levels and iNOS, COX-2, TNF-α and TNF R-2 expression in colonic tissue, and a decrease in IL-6 and TNF-α serum levels. MIE has anti-inflammatory activity in a DSS-induced rat colitis model and preventive administration (prior to DSS) seems to be a more effective protocol.