Fig. 1.

Effects of EWH or IRW on glucose uptake in L6 myotubes. Effects of EWH or IRW on glucose uptake in the absence or the presence of insulin (a, b). The myotubes were preincubated in 24-place multiwell plates in Krebs–Henseleit–Hepes buffer (KHH buffer) without glucose for 2 h. They were then incubated in KHH buffer containing 11 mM glucose without or with insulin and 5 mg/ml of EWH or 100 µM of IRW for 4 h. Effects of EWH or IRW on insulin-stimulated glucose uptake in TNF-α-treated L6 myotubes (c, d). The myotubes were incubated with EWH (1.25, 2,5, and 5 mg/ml) or IRW (25, 50, and 100 µM) 2 h prior to the treatment of 5 ng/ml of TNF-α for 24 h. Next, the myotubes were kept for 2 h in KHH buffer. The myotubes were then cultured in KHH buffer containing 11 mM glucose in the absence or the presence of 100 nm of insulin for another 4 h, and then, the glucose uptake was measured using a Glucose CII-Test Kit. Each value represents the mean ± SEM of five independent experiments. Single asterisk indicates p < 0.05 as compared to insulin alone. Double asterisk indicates p < 0.05 as compared to the insulin and TNF-α