title: Vitamin A-enriched diet modulates reverse cholesterol transport in hypercholesterolemic obese rats of the WNIN/Ob strain.
abstract: OBJECTIVE
  Vitamin A plays a major role in lipid metabolism. Previously, we reported that chronic vitamin A feeding (129 mg/kg) for two months normalized the abnormally high plasma HDL-cholesterol (HDL-C) levels in hypercholesterolemic obese rats by upregulating the hepatic scavenger receptor class B type 1 (SR-BI) expression. In this report, we hypothesize that the administration of a dose less than 129 mg of vitamin A/kg would also be effective in lowering the plasma HDL-C levels in these rats.
  
  
  METHODS
  Changes in the activity and expression of proteins related to RCT were analyzed together with blood parameters in five-month-old male lean and obese rats supplemented with 2.6 (control group), 26, 52 and 129 mg of vitamin A/kg as retinyl palmitate for 20 weeks.
  
  
  RESULTS
  Vitamin A supplementation in the obese rats decreased the plasma HDL-C levels with a concomitant increase in the hepatic SR-BI expression and lipase activity compared to that observed in the control diet-fed obese rats treated with 2.6 mg of vitamin A/kg diet. Furthermore, vitamin A supplementation at doses of 52 and 129 mg/kg diet reduced the plasma lecithin cholesterol acyltransferase activity and increased the hepatic ATP-binding cassette transporter protein A1 expression in the obese rats. Interestingly, most of these changes were not observed in the lean rats fed a vitamin A-enriched diet.
  
  
  CONCLUSIONS
  Chronic feeding of a vitamin A-enriched diet in hypercholesterolemic obese rats normalizes the plasma HDL-C level and presumably improves RCT, with an effective dose of 52 mg/kg diet. Further studies should focus on the pharmacological potential of vitamin A supplementation to correct an abnormal human obesity-associated lipoprotein metabolism.
authors.affiliation: Department of Lipid Biochemistry, National Institute of Nutrition (ICMR).
authors.forename: Anamthathmakula
authors.initials: A
authors.lastname: Prashanth
authors.forename: Shanmugam M
authors.initials: SM
authors.lastname: Jeyakumar
authors.forename: Nappan V
authors.initials: NV
authors.lastname: Giridharan
authors.forename: Ayyalasomayajula
authors.initials: A
authors.lastname: Vajreswari
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage; D001692:Biological Transport; D002784:Cholesterol / Q000378:metabolism*; D004032:Diet; D004224:Diterpenes; D006801:Humans; D006937:Hypercholesterolemia / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D008099:Liver / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000150:complications*; D051381:Rats; D011922:Rats, Mutant Strains; D000084562:Retinyl Esters; D013851:Thinness / Q000150:complications*; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D000975:Antioxidants; D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D002784:Cholesterol