Anti-diabetic effect and mechanism of action of MaEsil (Prunus mume) extract

Maesil (Prunus mume), is believed to be health food in oriental countries including Korea, and is presently reported to exert various physiological activities. However, anti-diabetic effect and underlying molecular mechanisms of Maesil are not reported. In the present study, we examined the anti-diabetic effect of Maesil, provided by Gwangyang City in C2C12 myotubes. A 70% ethanol extract of Maesil (EM) significantly stimulated the glucose uptake. In addition, we examined the activity of peroxisome proliferator-activated receptor gamma (PPAR-γ), a crucial target for the anti-diabetic action. EM significantly stimulated PPAR-γ transactivation. Moreover, we also investigated whether the 5′ AMP-activated protein kinase (AMPK), an insulin-independent anti-diabetic target, and Akt, an insulin-dependent anti-diabetic target, were involved in the stimulation of glucose uptake by EM. We found that EM did not stimulate the activations of AMPK and Akt. Finally, we screened 1318 differently expressed proteins by global protein analysis in the treatment of EM. We found that EM alters multiple protein expressions and signaling pathways. Taken together, these results suggest that EM exert anti-diabetic effect, at least in part via activation of PPAR-γ in cell culture systems. Therefore Maesil may be useful for the prevention of diabetes.