Modulatory effects of miracle fruit ethanolic extracts on glucose uptake through the insulin signaling pathway in C2C12 mouse myotubes cells.

Miracle fruit, Synsepalum dulcificum, is commonly known to be an alternative sweetener. It makes sour food taste sweet by affecting the tongue's taste receptors. It also shows beneficial health effects, such as antioxidant, anti-inflammatory, and antihyperglycemic activities. This study was conducted to investigate the antidiabetic effects of miracle fruit flesh (MF) and seed (MS) ethanolic extracts and the underlying mechanisms. Differentiated C2C12 myotubes were treated with the MF or MS extract (1-1,000 μg/ml) or metformin (1 mM) in the presence or absence of insulin. Compared with metformin, the MF extract significantly increased the intake of 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG). The MF extract also upregulated insulin receptor, phosphatidylinositol 3-kinase, and glucose transporter 4 expressions. These results reveal the antidiabetic effects of miracle fruit.