L-Arginine Supplementation Attenuates Oxidative Stress Mediated Gastrointestinal Dysfunction in Experimental Diabetic Rat

Gastrointestinal dysfunction in diabetes is an important microvascular complication. In the present study, we examined the effect of an anti-oxidant L-arginine on gastrointestinal function and oxidative stress in alloxan-induced diabetic rats. Adult SD rats were injected with alloxan to produce experimental oxidative stress characteristics of diabetes mellitus and maintained in this state for 8 weeks to produce gastrointestinal complication. Rats were treated with L-arginine (0.5mg/ml) through drinking water. Body weights, plasma glucose and glycosylated hemoglobin levels were measured at 0,12,21, and 57 days. At the termination of the experiments, gastric emptying, intestinal transit, and tissue motility were measured. Oxidative stress marker malonaldehyde, glutathione, superoxide dismutase and catalase were measured. Alloxaninjected rats showed significant increase in blood glucose, glycosylated hemoglobin, and decreased bodyweight. After 8 weeks, diabetic rats exhibited gastrointestinal dysfunction, evidenced by significant delay in gastric emptying, intestinal transit, and decreased contractile response of fundus and ileum to acetylcholine along with a marked increase in oxidative stress. L-arginine treatment significantly attenuated gastrointestinal dysfunction and oxidative stress in diabetic rats which confirm the role of oxidative stress in diabetic gastrointestinal complication and point to the possible anti-oxidative mechanism being responsible for the gastro protective action of L-arginine.