Therapeutic potential of peroxisome proliferators-activated receptor-α/γ dual agonist with alleviation of endoplasmic reticulum stress for the treatment of diabetes

Abstract

OBJECTIVE-Peroxisome proliferator-activated receptor (PPAE) α/γ dual agonists have the potential to be used as therapeutic agents for the treatment of type 2 diabetes. This study evaluated the function of macelignan, a natural compound isolated from Myristiea fragrans, as a dual agonist for PPARα/γ and investigated its antidiabetes effects in animal models. RESEARCH DESIGN AND METHODS-GAL4/PPAR chimera transactivation was performed and the expression of PPARα/γtarget genes was monitored to examine the ability of macelignan to activate PPARα/γAdditionally, macelignan was administrated to obese diabetic (db/db) mice to investigate antidiabetes effects and elucidate its molecular mechanisms. RESULTS-Macelignan reduced serum glucose, insulin, triglycerides, free fatty acid levels, and triglycerides levels in the skeletal muscle and liver of db/db mice. Furthermore, macelignan significantly improved glucose and insulin tolerance in these mice, and without altering food intake, their body weights were slightly reduced while weights of troglitazone-treated mice increased. Macelignan increased adiponectin expression in adipose tissue and serum, whereas the expression and serum levels of tumor necrosis factor-αand interleukin-α decreased. Macelignan downregulated inflammatory gene expression in the liver and increased AMP-activated protein kinase activation in the skeletal muscle of db/db mice. Strikingly, macelignan reduced endoplasmic reticulum (ER) stress and c-Jun NH2-terminal kinase activation in the liver and adipose tissue of db/db mice and subsequently increased insulin signaling. CONCLUSIONS-Macelignan enhanced insulin sensitivity and improved lipid metabolic disorders by activating PPARα/γand attenuating EE stress, suggesting that it has potential as an antidiabetes agent for the treatment of type 2 diabetes. © 2008 by the American Diabetes Association.