Activation of PPARγ by Cinnamon Extract Improves Glucose Regulation: Molecular and Physiological Insights

Abstract

Cinnamon is one of the oldest spices in the world and widely used as an anti-diabetic medicine. We have 
investigated the effect of Cinnamon zeylanicum extracts on involvement of important coactivators like 
PGC1α and SRC1 in potentiation of PPARγ activity. Present study demonstrates that 50:50 ethanol 
aqueous extract of Cinnamomum zeylanicum bark contains specific PPARγ agonists that activate PPARγ 
in HEK293/T cell based reporter assay and also dose-dependently potentiate the extract mediated PPARγ 
activity in presence of co-activators like PGC1α and SRC1, overexpressed in the cells. Knockdown of 
PGC1α gene by specific shRNA against PGC1α, significantly reduced the transactivation potentiation 
effect of extract induced by coactivator. The ability to activate PPARγ receptor is also supported by its 
adipogenic potential observed in mouse 3T3-L1 adipogenesis assay. The CZE3 extract improved glucose 
tolerance in the 12 h fasted C57BL/6 male mice. In summary aqueous ethanolic extract of Cinnamomum 
zeylanicum exhibits part of its glucose lowering effect via activation of PPARγ and extract mediated 
PPARγ activity is increased upon overexpression of PGC1α and SRC1 in a cell based in vitro assay.