Protective effects of walnut extract against oxidative damage in acetic acid-induced experimental colitis rats

Walnuts (Juglans regia), has been shown to exert anti-inflammatory and antioxidant effects. The present study was designed to evaluate the anti-inflammatory and antioxidant effects of walnut extract (WE) on an experimental model of ulcerative colitis caused by intracolonic administration of acetic acid in rats. A total number of 30 rats were used, randomly assigned to five groups of 6 rats each. Group I: colitis without treatment (colitis control), group II: normal animals (normal control), in groups III and IV colitis induced rats were treated with WE (10 and 20mg/kg) for 8 consecutive days, and group V were treated with sulfasalazine (SLS, 200mg/kg) as a standard drug. Several parameters, including macroscopic and histopathological scores and malondialdehyde (MDA), total sulfhydryl (SH) groups, colonic superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured using standard assay procedures. Results revealed that treatment with 10mg/kg WE for 8 days attenuated the macroscopic and histopathological colonic damage scores as well as colonic levels of MDA, while increased the levels of total SH, SOD and GPx compared with colitis untreated group. The 20mg/kg dose had no protective effects. These findings suggest that protective effect of WE in the experimental model of colitis could be through an antioxidant mechanism.