Pulmonary, gastrointestinal and urogenital pharmacologyCurcumin improves expression of ghrelin through attenuating oxidative stress in gastric tissues of streptozotocin-induced diabetic gastroparesis rats

The study was performed to investigate the improved effect of curcumin on gastrointestinal function in streptozotocin-induced diabetic rats. Curcumin was administrated intragastrically at a dose of 100, 200 and 400 mg/kg/day to diabetic rats. After 28 days of treatment, the activity of superoxide dismutase (SOD), catalase (CAT), the content of reduced glutathione (GSH) and malondialdehyde (MDA) in gastric mucosa was assayed. Furthermore, the gastric function was evaluated by hormone secretion and gastric emptying tests. The results indicated that: (i) the diabetic rats exhibited significant decreases in the above mentioned antioxidative enzymes activities and GSH level and exhibited a high level of MDA. After administration of curcumin, the parameters were ameliorated to a large extent; (ii) curcumin treatment dose-dependently augmented the ghrelin levels of stomach and plasma, which were earlier depleted in the diabetic control rats. Conversely, the expression of ghrelin mRNA was decreased after curcumin treatment; and (iii) the gastric emptying in curcumin treated diabetic rats was notably accelerated compared with the diabetic control rats. These findings showed an improved effect of curcumin against streptozotocin-induced gastroparesis possibly by its antioxidant property.