title: Vitamin D attenuates high fat diet-induced hepatic steatosis in rats by modulating lipid metabolism.
abstract: BACKGROUND
  Vitamin D has been reported to be reversely associated with type 2 diabetes and metabolic syndrome and is involved in modulation of lipid metabolism. The purpose of the present study was to determine whether 1,25-dihydroxyvitamin D(3) (1,25(OH)(2) D(3) ) has a protective effect on high fat diet (HFD)-induced hepatic steatosis in rats and to elucidate its underlying molecular mechanisms.
  
  
  METHODS
  Male Sprague-Dawley (SD) rats were fed with normal fat diet, HFD or HFD with intraperitoneal injection of 1, 2.5 and 5 μg/kg 1,25(OH)(2) D(3) , respectively, each 2 days for 8 weeks. Serum lipid profile and liver triglyceride were determined. Hepatic histology was examined by haematoxylin/eosin (H&E) and Oil Red O stainings. Hepatic gene expression involved in lipogenesis and lipid oxidation was analysed by quantitative reverse transcription-polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  The administration of 1,25(OH)(2) D(3) prevented HFD-induced body weight gain and reduced liver weight. 1,25(OH)(2) D(3) attenuated hepatic steatosis in a dose-dependent manner along with improved serum lipid profile. Furthermore, 1,25(OH)(2) D(3) downregulated mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c) and its target genes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) involved in lipogenesis. Peroxisome proliferator-activated receptor α (PPARα) and its target gene carnitine palmitoyltransferase-1 (CPT-1) involved in hepatic fatty acid (FA) oxidation were upregulated by 1,25(OH)(2) D(3) .
  
  
  CONCLUSIONS
  These results suggest that the preventing effect of 1,25(OH)(2) D(3) against HFD-induced hepatic steatosis is related to the inhibition of lipogenesis and the promotion of FA oxidation in rat liver.
authors.affiliation: Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yin
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Yu
authors.forename: Min
authors.initials: M
authors.lastname: Xia
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Luo
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Lu
authors.forename: Wenhua
authors.initials: W
authors.lastname: Ling
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects*; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism; D005234:Fatty Liver / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D009929:Organ Size; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics* / Q000378:metabolism; D014280:Triglycerides / Q000235:genetics / Q000378:metabolism
chemical_list: D047493:PPAR alpha; D012333:RNA, Messenger; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D002334:Carnitine O-Palmitoyltransferase; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase; D002117:Calcitriol