Light microscopy of C2C12 myotubes treated with WF (5, 10, 15, 20, 25 μg.mL-1 for 24 h). A, in the absence of WF, C2C12 myotubes had a normal, elongated shape. B-F, C2C12 myotubes incubated for 24 h with 5 (B), 10 (C), 15 (D), 20 (E) and 25 (F) μg of WF.mL-1. The morphological analysis of WF-treated C2C12 cells revealed a loss of cell-to-cell contact and consequent detachment (white arrows), cell retraction and a change in cell shape (arrowheads). Lens 40×.