Figure 5.

AMPK signaling is involved in the protective effect of metformin against H₂O₂-induced cell damage. (a) D407 cells were treated with 1 mM metformin for the periods of time indicated, and then, P-AMPK levels were assessed by Western blot. (b) Quantitative analysis of (a). (c) D407 cells were treated with different concentrations of metformin for 2 h, and then, P-AMPK levels were assessed by Western blot. (d) Quantitative analysis of (c). (e) D407 cells were pretreated with 1 mM metformin and then incubated with or without 200 μM H₂O₂ for further 24 h. The expression of AMPK was assessed by ICC (scale bars, 200 μm). Data are presented as the mean ± SD; ^∗∗p < 0.01.