Lipid metabolism and inflammation modulated by Vitamin D in liver of diabetic rats

BACKGROUND: In recent years, much evidence suggested that vitamin D plays an important role in decreasing the risk of type 2 diabetes. The purpose of this study was to investigate whether 1, 25 (OH) (2)D(3) can modulate inflammation and lipid metabolism in type 2 diabetic rat liver. METHODS: Type 2 diabetes was induced in SD rat with high-fat and high-sugar diets and multiple low-dose streptozotocin. The levels of serum calcium, phosphorus, glucose, TC, TG, AST, ALT and hepatic TG were determined. H & E staining were performed to assess the effects of vitamin D treatment on pathological changes in the liver tissues. Immunohistology, real-time PCR and Western blot were used to evaluate the expressions of NF-κ B, MCP-1, ICAM-1, TGF-β1, PPAR-α and CPT-1. RESULTS: The administration of 1, 25 (OH) (2)D(3) reduced liver weight. Compared to DM rats, 1, 25 (OH) (2)D(3)-treated DM rats had lower liver weight. Moreover, compared to healthy or 1, 25 (OH) (2)D(3)-treated DM rats, DM rats had increased hepatic transcription factors (NF-κ B), monocyte chemoattractant protein −1 (MCP-1), intercellular adhesion molecule −1 (ICAM-1), transforming growth factor-β1 (TGF-β1) expressions, but had fewer hepatic PPAR- α and CPT-1 expressions. CONCLUSIONS: 1, 25 (OH) (2)D(3) significantly modulated the liver inflammation and lipid metabolism in diabetic rat models, which may be caused by its regulations on hepatic signaling NF-κ B pathway and PPAR- α.