The functional status of glutathione (GSH), its related enzymes and Cu, Zn-superoxide dismutase (SOD) in colonocytes isolated from trinitrobenzene sulphonic (TNBS)-induced colitis rats was studied. Colitis (T group) was induced in Wistar rats with 42 mg TNBS dissolved in 0.35 ml of 40% (v/v) ethanol instilled into the colon. The animals were sacrificed on day 14 and compared with saline-instilled rats (S group). The GSH concentration and the enzymatic activities of glutathione peroxidase (GPx), glutathione S-transferase (GST), and SOD were spectrophotometrically estimated. The severity of colitis was assessed histologically and by myeloperoxidase activity (MPO) in whole colonic tissue. The body weight loss of the rats in the T group was marked. In colonocytes isolated from rats in the T group, the concentration of GSH (7.9 ±1.4 vs.11.3 ± 0.4 nmol/mg protein, p < 0.05) and the activities of GST (104.4 ± 10.3 vs. 146.2 ± 18.5 mU/mg protein, p < 0.05) and SOD (74.4 ± 8.9 vs. 99.8 ± 7.5U/mg protein, p < 0.05) were lower, but the activity of GPx (430.0 -±14.1 vs. 283.9 ± 10.0 mU/mg protein, p < 0.05) was higher than in the S group. As expected, the activity of MPO in the T group was higher than in the S group (371.2 ± 14.7 vs. 158.9 ± 8.4 mU/mg tissue, p<0.05) and histologically, colitis was only observed in rats in the T group. In conclusion, the functional status of antioxidants in the colonic epithelial cells of rats challenged with TNBS solution is impaired. This impariment may make them more susceptible to oxidative damage that may contribute to the development of the lesions observed in this model. Further studies at the molecular level are necessary to investigate these novel findings in this model and their potential application for testing new therapeutic approaches in inflammatory diseases of the intestinal tract.