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) D-2(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-kappa B, MCP-1, ICAM-1, TGF-beta 1, PPAR-a and CPT-1. Results: The administration of 1, 25 (OH) D-2(3) reduced liver weight. Compared to DM rats, 1, 25 (OH) D-2(3)-treated DM rats had lower liver weight. Moreover, compared to healthy or 1, 25 (OH) D-2(3)-treated DM rats, DM rats had increased hepatic transcription factors (NF-kappa B), monocyte chemoattractant protein -1 (MCP-1), intercellular adhesion molecule -1 (ICAM-1), transforming growth factor-beta 1 (TGF-beta 1) expressions, but had fewer hepatic PPAR-a and CPT-1 expressions. Conclusions: 1, 25 (OH) D-2(3) significantly modulated the liver inflammation and lipid metabolism in diabetic rat models, which may be caused by its regulations on hepatic signaling NF-kappa B pathway and PPAR-a.