Naringenin and insulin enhance the phosphorylation of ERK1/2 and MAPKp38. HepG2 cells in serum-free media were incubated ± naringenin (100 μmol/l) or insulin (100 nmol/l) for 15, 30, or 60 min.
Total and phosphorylated ERK1/2 (A) and total and phosphorylated MAPKp38 (B) were measured by immunoblotting and are presented as the ratio of phosphorylated form to total protein (relative to control).
Values are means ± SE for at least three experiments. *P < 0.05, **P < 0.01 compared with control.