Dietary lipoic acid-dependent changes in the activity and mRNA levels of hepatic lipogenic enzymes in rats.
Effects of dietary alpha-lipoic acid on hepatic and serum lipid concentrations and the activity and mRNA levels of lipogenic enzymes were examined in rats. Rats were fed experimental diets containing varying amounts of lipoic acid (0, 1, 2.5, 5 g/kg) for 21 d. Lipoic acid profoundly decreased serum and liver concentrations of TAG, and also lowered serum concentrations of phospholipid and NEFA, and the concentration of cholesterol in the liver. A hypoglycaemic effect of this compound was also observed. Lipoic acid dose-dependently decreased the activity and mRNA levels of fatty acid synthase, ATP-citrate lyase, glucose 6-phosphate dehydrogenase, malic enzyme and pyruvate kinase in the liver despite that reductions were considerably attenuated in the NADPH-producing enzymes. This compound also dose-dependently lowered the mRNA levels of spot 14, adiponutrin, stearoyl-CoA desaturase 1, and Delta5- and Delta6-desaturases. In addition, lipoic acid dose-dependently lowered serum concentrations of insulin and leptin, but increased those of adiponectin. Lipoic acid appeared to reduce hepatic lipogenesis and hence decreases serum and liver lipid levels. Alterations in serum concentrations of insulin and (or) adiponectin may trigger this consequence.
Laboratory of Nutritional Function, Division of Food Function, National Food Research Institute, 2-1-12 Kannondai, Tsukuba 305-8642, Japan.
Doan Thi Thanh
DT
Huong
Takashi
T
Ide
D054392:Adipokines / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000096:biosynthesis; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism / Q000187:drug effects; D050155:Lipogenesis / Q000187:drug effects; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D008063:Thioctic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D014280:Triglycerides / Q000378:metabolism
D054392:Adipokines; D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D012333:RNA, Messenger; D014280:Triglycerides; D008063:Thioctic Acid