NLRP3 inhibitor glibenclamide attenuates high-fat diet and streptozotocin-induced non-alcoholic fatty liver disease in rat: studies on oxidative stress, inflammation, DNA damage and insulin signalling pathway.

The prevalence of non-alcoholic fatty liver disease (NAFLD) is much higher in diabetic and obese individuals. Combined exposure of high-fat diet (HFD) and single low-dose streptozotocin (STZ) was used to induce type II diabetes-associated NAFLD, as it better replicates the human pathology of fatty liver. Glibenclamide (GLB) is a potent NLRP3 inflammasome inhibitor and possesses anti-inflammatory and anti-oxidant properties. So it was pertinent to investigate its hepatoprotective potential against NAFLD in rat. HFD was provided to rat for 17 consecutive weeks and glibenclamide (GLB; 0.5 and 2.5 mg/kg/day, orally) was administered for the last 12 consecutive weeks. Establishment of NAFLD was clearly indicated by significant increase in liver weight, glucose, triglyceride, cholesterol, % glycosylated haemoglobin and insulin levels, and GLB intervention reduced the same. GLB restored HFD-induced significant increase in ROS, MDA and decrease in GSH. Histopathological studies revealed the macro- and micro-vascular steatosis and mild degree of inflammation in HFD-fed rat compared with control, and GLB intervention reduced the same. HFD exposure significantly increased the DNA damage and apoptosis compared with control, and GLB intervention reduced the same. Immunohistochemical and immunoblotting findings showed that GLB improved the hepatic expressions of inflammatory markers (NLRP3, ASC, caspase-1, IL-1β, NF-κB), anti-oxidant markers (SOD, catalase) and insulin signalling markers (p-AKT, p-GSK-3β, p-IRS). Hepatoprotective effects of GLB was mediated by decreasing the levels of glucose, triglycerides, cholesterol, DNA damage, apoptosis and inflammatory markers, and by improving the anti-oxidant status and insulin signalling pathway in HFD fed rat.