Effect of berberine on glucolipid metabolization in diabetic skeletal muscle and its mechanism

摘要

Aim To investigate the effect of berberine on damaged morphology and glucolipid metabolization in skeletal muscle of diabetic rat and the relationship between peroxisome proliferator-activated receptor (PPARs) α/γ/δ protein expression. Methods Type 2 diabetes mellitus rats were induced by an injection of 35 mg·kg~(-1) streptozotocin (STZ) and a high-carbohydrate/ high-fat diet for 16 weeks. From week 17 to 32, diabetic rats were given low-, middle-, high-dose berberine (75, 150, 300 mg·kg~(-1)), fenofibrate (100 mg·kg~(-1)) and rosiglitazone (4 mg·kg~(-1)) by oral administration, respectively. The skeletal muscle structure was observed with hematoxylin-eosin (HE) staining, glycogen and triglyceride contents were measured by spectrophotometry and PPAR α/γ/δ protein expressions were detected by immunohistochemistry. Results Fiber distribution remained normal in skeletal muscles of all the groups, middle-, high-dose berberine partly improved diabetic fibre atrophy, increased glycogen and decreased triglyceride levels in diabetic muscle (P < 0.01). Middle-, high-dose berberine and rosiglitazone all significantly reduced PPARγ protein level in diabetic skeletal muscle (P < 0.01); middle-, high-dose berberine and fenofibrate strikingly increased both PPARα and PPARδ expression (P < 0.01). Conclusion Berberine modulates PPAR α/γ/δ protein expression in diabetic skeletal muscle which may contribute to ameliorate fibre damage and glucolipid metabolization.