Effects of melatonin preconditioning on hepatic ischemia-reperfusion injury in rats with nonalcoholic fatty liver disease / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of melatonin preconditioning on hepatic ischemia-reperfusion (I/R) injury in rats with non-alcoholic fatty liver disease (NAFLD).Methods:Forty-eight SPF male Sprague-Dawley rats, aged 10-12 weeks, weighing 200-230 g, were divided into 4 groups ( n=12 each) using a random number table method: control group (Con group), NAFLD group, NAFLD + hepatic I/R group (NAFLD+ HIR group), and NAFLD + hepatic I/R + melatonin treatment group (NAFLD+ HIR+ MT group). The NAFLD model was developed by a high-fat and high-glucose diet (10% glucose, 10% fat) for 8 consecutive weeks in NAFLD, NAFLD+ HIR and NAFLD+ HIR+ M groups, and rats were fed with common chow and freely drank water in the other groups.Melatonin 10 mg/kg was given intragastrically daily for 2 consecutive weeks before developing the model in group NAFLD+ HIR+ MT.The model of liver I/R injury was developed by clipping the hepatic artery and portal vein for 20 min, opening for 5 min, and re-clamping for 20 min followed by restoration of perfusion.Blood samples from inferior vena cava were collected and liver tissues were obtained at 6 h of reperfusion to detect serum levels of insulin, blood glucose, free fatty acid (FFA), triglyceride (TG), alanine aminotransferase (ALT), aspartate amino transferase (AST) and ferritin, and insulin resistance index was calculated.The levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), reactive oxygen species (ROS) and Fe 2+ in liver tissues were detected by enzyme-linked immunosorbent assay, the pathological changes of liver tissues were examined with a light microscope after hematoxylin-eosin staining.The expression of nuclear factor E2-related factor 2 (Nrf2), lysophosphatidylcholine acyltransferase 3 (LPCAT3), long-chain fatty acyl-CoA synthase 4 (ACSL4) and glutathione peptide peroxidase 4 (GPX4) was detected by Western blot. Results:Compared with Con group, the levels of serum FFA, TG, ALT, AST and ferritin and insulin resistance index were significantly increased, the levels of ROS and Fe 2+ in liver tissues were increased, the levels of GSH-Px and SOD were decreased, the expression of ACSL4 and LPCAT3 was up-regulated, and the expression of Nrf2 and GPX4 was down-regulated in NAFLD group ( P<0.05). Compared with NAFLD group, the serum levels of FFA, TG, ALT, AST and ferritin and insulin resistance index were significantly increased, the levels of ROS and Fe 2+ were decreased, the levels of GSH-Px and SOD were increased, the expression of ACSL4 and LPCAT3 was up-regulated, and the expression of Nrf2 and GPX4 was down-regulated in NAFLD+ HIR group ( P<0.05). Compared with NAFLD+ HIR group, the serum levels of FFA, TG, ALT, AST and ferritin and insulin resistance index were significantly increased, the levels of ROS and Fe 2+ were decreased, the levels of GSH-Px and SOD were increased, the expression of ACSL4 and LPCAT3 was down-regulated, and the expression of Nrf2 and GPX4 was up-regulated in NAFLD+ HIR+ MT group ( P<0.05). Conclusions:Melatonin preconditioning can alleviate hepatic I/R injury in rats with NAFLD, and the mechanism may be related to activation of Nrf2 signaling pathway, reduction of lipid peroxidation and inhibition of ferroptosis.