Protective effect of naringin ameliorates TNBS-induced colitis in rats via improving antioxidant status and pro-inflammatory cytokines

Aim: Ulcerative colitis (UC) is a chronic inflammatory bowel disease that disturbs the colon mucosal lining and is characterized by oxido-nitrosative stress and the release of pro-inflammatory cytokines. Naringin (NG) belongs to a group of chemicals called bioflavonoids derived from grapefruit and related citrus species. NG has been widely used as folk medicine in many countries, due to its several health benefits. Method: This study examined the effect of NG on 2,4,6 trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. Forty-two male Wistar rats were divided into seven groups like Normal Control (NC), Ethanol Control (EC), Disease Control (DC), NG 20 (20 mg/kg, p.o.), NG 40 (40 mg/kg, p.o.), NG 80 (80 mg/kg, p.o.), and Dexamethasone (DEX) (2 mg/kg, p.o.). Colitis was induced in Wistar albino rats by administering TNBS intra-rectally (in 50% ethanol). The rats were then given 14 days of NG (20, 40, and 80 mg/kg) and DEX (2 mg/kg) treatment. Several behavioral, biochemical, molecular, and histological analyses were performed. Result: The treatment of rats with NG significantly increased the body weight (p < .05, p < .01), hematological parameters like hemoglobin (p < .05, p < .01, p < .001), red blood cells (p < .01, p < .001), and platelets count (p < .01, p < .001) and decreased in spleen weight (p < .01, p < .001), colon weight (p < .01, p < .001), colon weight to length ratio (p < .05, p < .01, p < .001), macroscopic score (p < .01, p < .001), adhesion score (p < .01, p < .001), diarrhea score (p < .05, p < .001), stool consistency (p < .01, p < .001), rectal bleeding score (p < .05, p < .01, p < .001), white blood cells count (p < .01, p < .001). NG significantly (p < .01, p < .001) increased colonic superoxide, glutathione, and catalase levels and decreased malondialdehyde and myeloperoxidase levels. It also significantly (p < .01, p < .001) decreased the biochemical parameters, proinflammatory cytokines and reduced the histological damage in the colon tissue caused by TNBS. Conclusion: Our results demonstrated that NG treatment attenuated pathologic changes of TNBS-induced colitis in rats through restoring colonic damage and reducing inflammatory response in the colon tissue. Thus, NG might be considered as an effective candidate for the treatment of UC patients.

Automated summary

The study demonstrated that treatment with NG effectively alleviated TNBS-induced colitis in rats by improving body weight, hematological parameters, reducing spleen and colon weight, alleviating symptoms, as well as decreasing inflammatory response and repairing tissue damage.