Effects of Glycyrrhetic Acid (GE) on Some Gluconeogenic Enzymes, Lipoprotein Lipase and Peroxisome Proliferator-Activated Receptors Alpha and Gamma

Abstract

The aim of this study was to examine the role of glycyrrhetic acid (GE) as a potential compound in the amelio- ration of metabolic syndrome. Rats given intraperitoneal injection of GE were sacrificed after 24 hours. Blood was col- lected for the determination of glucose, insulin and lipid profiles; while tissues were used for 11� -HSD1, gluconeogenic enzymes activities, PPAR-� /-� and LPL expression by RT-PCR. Intraperitoneal injection of 50mg/kg GE to normal rats significantly lowered blood glucose while insulin level and HOMA-IR showed no significant changes. H6PDH activities increased in the liver, kidney, subcutaneous and visceral adipose tissues and quadriceps femoris but decreased in the ab- dominal muscle. PEPCK activities were significantly reduced in the kidney and decreased in the liver but showed an in- crease in the subcutaneous and visceral adipose tissues. G6Pase activities were found to be reduced in both the liver and kidney. 11� -HSD1 activities increased in the liver but decreased in all other tissues. There were improvements in lipid profiles in GE-treated rats. Up-regulation of LPL activity was seen in all tissues except quadriceps femoris. PPAR-� ex- pression was up-regulated in the liver, heart and abdominal muscle while down-regulated in the kidney and quadriceps femoris but were undetectable in the subcutaneous and visceral adipose tissues. PPAR-� expression was up-regulated in all tissues except the kidney. GE prevented hyperglycaemia and improved lipid profiles possibly through 11� -HSD1 inhi- bition instead of via PPAR agonism.