TNBS-induced colitis

Male Wistar rats, weighing 200 ± 21 g, were obtained from Harlan Italy and were housed in a temperature-controlled environment with a 12-hour light-dark cycle, and given free access to regular laboratory chow diet and water for at least one week. All animals received human care and the study protocol was approved by the Committee of Laboratory Animals of Federico II University according to institutional guidelines. Rats then were given a single enema of 0.5 ml TNBS solution (12% in 50% ethanol-water), via a rubber catheter inserted 8 cm from the anus under light anesthesia.²⁴