The effect of boletus polysaccharides on diabetic hepatopathy in rats

The objective of this work was to investigate the effect of boletus polysaccharide (BPS) on diabetic hepatopathy in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats for the first time. The rats were fed with high-fat diet (HFD) for 4 weeks and induced with STZ by a single intraperitoneal injection to develop T2DM model. The HFD was given continually for another 4 weeks after diabetes induction, following the drugs of BPS (400 mg/kg bw/day) infused to stomach of rats once a day. After the administration, blood was drawn from the posterior orbital venous plexus of the inner canthus and the rats were then sacrificed. The blood glucose and lipid, alanine transaminase (ALT) and aspartate transaminase (AST) were detected immediately. Besides, their livers were dissected for biochemical and histopathological assays. And the levels of malonaldehyde, glutathione and antioxidant enzymes in liver were detected. In addition, histopathological examinations of liver were performed to verify the liver injury. The expressions of NF-κB, TNF-α, SREBP1c, and CYP7A1 were test to trace out the mechanistic pathways. Compared with T2DM model group, the blood glucose, TC, TG, ALT, AST, and MDA and so on were significantly reduced, and CAT, SOD, GSH, GPx were significantly increased in the rats treated with BPS. The histopathological examination showed the liver injury in BPS treated rats was alleviated. The expressions of SREBP1c, NF-κB and TNF-α were significantly decreased, and the expressions of CYP7A1 was significantly increased. All these experimental findings demonstrate that BPS exhibited antidiabetic effects rats possibly through its inhibition of oxidative stress and inflammation, supporting that BPS has a promising therapeutic effect in the treatment of diabetic hepatopathy in rats.