Effects of lipoic acid on AMPK and adiponectin in adipose tissue of low- and high-fat-fed rats.
BACKGROUND
Lipoic acid (LA) is an antioxidant with antiobesity and antidiabetic properties. Adiponectin is an adipokine with potent anti-inflammatory and insulin-sensitizing properties. AMP-activated protein kinase (AMPK) is a key enzyme involved in cellular energy homeostasis. Activation of AMPK has been considered as a target to reverse the metabolic abnormalities associated with obesity and type 2 diabetes.


OBJECTIVE
The aim of this study was to determine the effects of LA on AMPK phosphorylation and adiponectin production in adipose tissue of low-fat (control diet) and high-fat diet-fed rats.


RESULTS
Dietary supplementation with LA reduced body weight and adiposity in control and high-fat-fed rats. LA also reduced basal hyperinsulinemia as well as the homeostasis model assessment (HOMA) levels, an index of insulin resistance, in high-fat-fed rats, which was in part independent of their food intake lowering actions. Furthermore, AMPK phosphorylation was increased in white adipose tissue (WAT) from LA-treated rats as compared with pair-fed animals. Dietary supplementation with LA also upregulated adiponectin gene expression in WAT, while a negative correlation between adiposity-corrected adiponectin levels and HOMA index was found. Our present data suggest that the ability of LA supplementation to prevent insulin resistance in high-fat diet-fed rats might be related in part to the stimulation of AMPK and adiponectin in WAT.
Department of Nutrition, Food Science, Physiology and Toxicology, University of Navarra, Pamplona, Spain.
Pedro L
PL
Prieto-Hontoria
Patricia
P
Pérez-Matute
Marta
M
Fernández-Galilea
J
J
Alfredo Martínez
María J
MJ
Moreno-Aliaga
D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D052242:Adiponectin / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism; D052436:Adipose Tissue, White / Q000187:drug effects* / Q000378:metabolism; D050154:Adiposity / Q000187:drug effects; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage; D019587:Dietary Supplements; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D018482:Muscle, Skeletal; D009765:Obesity / Q000517:prevention & control; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D008063:Thioctic Acid / Q000494:pharmacology*; D015430:Weight Gain
D052242:Adiponectin; D001786:Blood Glucose; D004041:Dietary Fats; D007328:Insulin; D008063:Thioctic Acid; D055372:AMP-Activated Protein Kinases