Fig. 2

Metformin significantly suppressed the morphine-induced inflammatory response in a SOCS3-dependent manner in BV-2 cells. BV-2 cells were pretreated with metformin (2.5 mM) for 12 h and then exposed to morphine (200 μM) for 12 h. Cells were collected and analyzed. a–c Western blot analysis showed the phosphorylation of p38 (a) and p65 (b) and the protein level of SOCS3 (c) (n = 3). BV-2 cells were transfected with 100 pmol SOCS3 siRNA or negative control (NC) siRNA for 36 h. Then, the cells were subjected to metformin (2.5 mM) for 12 h, followed by exposure to morphine (200 μM) for 12 h. Cell extracts were collected and analyzed. d, e The protein level of SOCS3 (d) and phosphorylation of p65 (e) were evaluated by western blot (n = 3). f, g The mRNA levels of Il1b (f) and Tnfa (g) were evaluated by real-time PCR (n = 3). Data were analyzed by one-way ANOVA. *p < .05, **p < .01, ***p < .001 vs. the control group; ^#p < .05, ^##p < .01, ^###p < .001 vs. the morphine-treated group. ^$p < .05, ^$$p < .01, ^$$$p < .001 vs. morphine and metformin-coadministered group