RESUMEN
The present study was aimed to evaluate the ameliorative potential of melatonin against L-arginine induced acute pancreatitis in rats. Male Sprague Dawley rats (150–240 g) were divided into 3 groups, viz. group I (control group), group II (acute pancreatitis control group) and group III (treatment control) which were further subdivided into 3 subgroups according to time points of 24 hours, 3 days and 7 days. Rats from groups II and III received two injections of L-arginine (2 g/kg i.p.) at 1 h intervals for induction of acute pancreatitis. Melatonin was administered to group III daily at a single dose of 10 mg/kg i.p. On 6 hours, 24 hours, 3 days and 7 days, blood samples were obtained from each group and subjected for the assays of oxidative stress and serum biochemical parameters. Erythrocytic lipid peroxides contents in acute pancreatitis group were significantly higher, while reduced glutathione contents were significantly lower in comparison with the normal controls. The activities of other antioxidant enzymes were also significantly low in these rats. Moreover, significantly increased activities of serum amylase and serum lipase were found in these rats. Administration of melatonin significantly reduced the over production of malonaldialdehyde levels. Other antioxidant enzymes viz. reduced glutathione, superoxide dismutase and catalase activities were improved significantly in melatonin treated rats. Melatonin had also considerably ameliorated the altered serum amylase and serum lipase levels towards normalcy. Thus, it can be concluded that melatonin may possess therapeutic efficacy against L-arginine induced acute pancreatitis in rats