Pharmacological research : the official journal of the Italian Pharmacological Society
-
Type 2 diabetes is characterized by insulin resistance in target tissues and hyperglycemia. Catalpol is a natural product isolated from the root of Rehmannia glutinosa, which has been reported to produce the effect of anti-diabetes in recent reports. The goal of the current study is to investigate the therapeutic effects of catalpol on hepatic insulin resistance in type 2 diabetes and elucidate the underlying cellular mechanisms. ⋯ Furthermore, the effect of catalpol on depriving glucosamine-induced insulin resistance was prevented by knockdown of NOX4 or AMPK with short interfering RNA (siRNA) in HepG2 cells. Moreover, the suppressive effect of catalpol on glucosamine-induced NOX4 over-expression was weakened by knockdown of AMPK with siRNA. Taken together, these findings suggested that catalpol ameliorated hepatic insulin resistance in type 2 diabetes through acting on AMPK/NOX4/PI3K/AKT pathway.