Saponins from Helicteres isora have previously been shown to exert antidiabetic effects. The present study explored the underlying mechanisms in C2C12 skeletal muscle cells. Western blotting revealed that incubation with saponins (100mg/ml) and sapogenin (100mg/ml) induced the phosphorylation of phosphatidylinositol -3-kinase (PI3K) as well as the downstream target proteins kinase B/Akt (at Ser473) and the glycogen synthase kinase GSK-3a/b (at Ser21/9) in a time dependent manner. In contrast, there was no phosphorylation of AMP sensitive kinase AMPK (at Thr172). Within 48 h saponin/sapogenin-treatment further increased the Glut4 protein levels. Immunofluorescence confocal microsopy confirmed that saponin/sapogenin treatment stimulates PKB/Akt phospho-rylation and revealed that the treatment was followed by translocation of the glucose transporter Glut4 into the myotube cell membrane. In conclusion, saponins and sapogenin activate the PI3K/AKT pathway thus leading to increased Glut4 dependent glucose transport across the cell membrane as well as to phosphorylation and inactivation of GSK-3a/b with subsequent stimulation glycogen synthesis.