Salacia oblonga root improves cardiac lipid metabolism in Zucker diabetic fatty rats: modulation of cardiac PPAR-alpha-mediated transcription of fatty acid metabolic genes.
Excess cardiac triglyceride accumulation in diabetes and obesity induces lipotoxicity, which predisposes the myocytes to death. On the other hand, increased cardiac fatty acid (FA) oxidation plays a role in the development of myocardial dysfunction in diabetes. PPAR-alpha plays an important role in maintaining homeostasis of lipid metabolism. We have previously demonstrated that the extract from Salacia oblonga root (SOE), an Ayurvedic anti-diabetic and anti-obesity medicine, improves hyperlipidemia in Zucker diabetic fatty (ZDF) rats (a genetic model of type 2 diabetes and obesity) and possesses PPAR-alpha activating properties. Here we demonstrate that chronic oral administration of SOE reduces cardiac triglyceride and FA contents and decreases the Oil red O-stained area in the myocardium of ZDF rats, which parallels the effects on plasma triglyceride and FA levels. Furthermore, the treatment suppressed cardiac overexpression of both FA transporter protein-1 mRNA and protein in ZDF rats, suggesting inhibition of increased cardiac FA uptake as the basis for decreased cardiac FA levels. Additionally, the treatment also inhibited overexpression in ZDF rat heart of PPAR-alpha mRNA and protein and carnitine palmitoyltransferase-1, acyl-CoA oxidase and 5'-AMP-activated protein kinase mRNAs and restored the downregulated acetyl-CoA carboxylase mRNA. These results suggest that SOE inhibits cardiac FA oxidation in ZDF rats. Thus, our findings suggest that improvement by SOE of excess cardiac lipid accumulation and increased cardiac FA oxidation in diabetes and obesity occurs by reduction of cardiac FA uptake, thereby modulating cardiac PPAR-alpha-mediated FA metabolic gene transcription.
Huang
Tom Hsun-Wei
TH
Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW 2006, Australia.
Yang
Qinglin
Q
Harada
Masaki
M
Uberai
Jasna
J
Radford
Jane
J
Li
George Q
GQ
Yamahara
Johji
J
Roufogalis
Basil D
BD
Li
Yuhao
Y
D000818:Animals; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins / Q000235:genetics; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism; D006352:Heart Ventricles / Q000187:drug effects / Q000378:metabolism*; D050356:Lipid Metabolism / Q000187:drug effects* / Q000235:genetics; D008297:Male; D008515:Medicine, Ayurvedic; D009206:Myocardium / Q000473:pathology; D009765:Obesity / Q000150:complications / Q000378:metabolism*; D047493:PPAR alpha / Q000235:genetics* / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011924:Rats, Zucker; D049918:Salacia / Q000737:chemistry*; D014158:Transcription, Genetic / Q000187:drug effects*; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
D050556:Fatty Acid-Binding Proteins; D005230:Fatty Acids, Nonesterified; D047493:PPAR alpha; D010936:Plant Extracts; D012333:RNA, Messenger; C493570:Slc27a1 protein, rat; D014280:Triglycerides; D002784:Cholesterol