We investigated the effects and regulatory mechanism of submerged culture of Ceriporia lacerata mycelium (FBS0P) on high fat diet-induced diabetic mice with insulin resistance and C2C12 myotubes. In order to examine the in vivo effects of treatment with FBS0P, FBS0P (500 mg/kg/d) was orally administered to high fat-fed male mice for 4 weeks. An oral glucose tolerance test was performed by measuring blood glucose levels following an oral glucose load. In the results, the FBS0P-treated mice group showed improved insulin sensitivity while FBS0P treatment reduced serum insulin and c-peptide levels, compared to the high fat diet group. High fat diet-induced mice with FBS0P showed increasing adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and glucose transporter 4 (GLUT4) expression levels in gastrocnemius muscles. To determine the down-stream mechanism, C2C12 myotubes were incubated with and without FBS0P. Treatment with FBS0P increased AMPK phosphorylation and glucose uptake by inducing GLUT4 translocation in C2C12 myotubes. Furthermore, FBS0P improved insulin sensitivity in tumor necrosis factor α-treated myotubes. The present investigation demonstrates that FBS0P from submerged culture of C. lacerata mycelium exhibits antihyperglycemic efficacy both in a cell culture system and in a high fat-fed diabetic mice model by overcoming insulin resistance.

Keywords: Ceriporia lacerata, diabetes, high fat diet-induced diabetic mice, insulin resistance, natural products