The Effect Of Berberine On Autophagy Associated Proteins In Pancreatic Tissue Of Rats With Type2Diabetes

ObjectiveTo investigate the effect of berberine on glucose and lipid metabolism and autophagyassociated proteins in pancreatic tissue of rats with type2diabetes.MethodsThe rat model of type2diabetes was established by intravenous injection of small dosesof streptozotocin (STZ) and feeding with a high-fat diet for4weeks. Then the rats wererandomly divided into5groups: model (Mod) group, berberine (Bbr) group, metformin(Met) group, adenylate-activated protein kinase (AMPK) activator (AICAR) group andnormal control (Con) group. The corresponding therapy was administered to rats in Bbr,Met and AICAR groups for12weeks. Oral glucose tolerance test (OGTT), fasting seruminsulin (FINS), total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol(LDL-C), high density lipoprotein-cholesterol (HDL-C) were assayed and HOMA-IR wascalculated. Western blot was used to analyze the protein expressions of AMP-activatedprotein kinase (AMPK), serine/threonine kinase, STKl1(LKB1), tuberous sclerosiscomplex1(TSC1) and microtubule-associated protein1light chain protein3(LC3-II) inpancreatic tissue.ResultsCompared with normal group, blood glucose, FINS, HOMA-IR, TC, TG, LDL-C of the rats in model group were increased while serum HDL-C level was reduced (P<0.01).Compared with the model group, blood glucose, FINS, HOMA-IR, TC, TG, LDL-C of therats in berberine group were decreased while serum HDL-C level was increased (P<0.01).Western blot analysis showed that the expression of AMPK and LKB1proteins werereduced, but the expression of TSC1and LC3-II proteins was increased in the rats in modelgroup (P<0.05, P<0.01). Compared with model group, the expression of AMPK, LKB1,TSC1and LC3-II proteins were increased in the rats in the berberine, metformin andAICAR groups (P <0.05, P <0.01).ConclusionBerberine has the potential to attenuate the disturbance of glucose and lipidmetabolism in rats with type2diabetes. The mechanism might be associated withincreasing the expression of LKB1, AMPK, TSC1and LC3-Ⅱ proteins in pancreatictissue.