OBJECTIVE

Peroxisome proliferator-activated receptor (PPAR) alpha/gamma 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 Myristica fragrans, as a dual agonist for PPARalpha/gamma and investigated its antidiabetes effects in animal models.

RESEARCH DESIGN AND METHODS

GAL4/PPAR chimera transactivation was performed and the expression of PPARalpha/gamma target genes was monitored to examine the ability of macelignan to activate PPARalpha/gamma. Additionally, 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-alpha and interleukin-6 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 NH(2)-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 PPARalpha/gamma and attenuating ER stress, suggesting that it has potential as an antidiabetes agent for the treatment of type 2 diabetes.