Figure 5: Activation of melanin-related protein tyrosinase and microphthalmia-associated transcription factor/mitogen-activated protein kinase signaling pathways in B16F10 cells under tanshinone IIA treatment. The cells were treated with tanshinone IIA (1, 3, and 10 μM) and incubated for 72h. (a) Representative immunoblots probed with antibodies against Tyr, MITF, p-P38, P38, p-JNK, JNK, p-ERK1/2, ERK1/2 and β-actin, as indicated. Phosphorylation expression levels of (b) p38, (c) Jun N-terminal kinase, and (d) Extracellular signal-regulated protein kinase 1/2. (e and f) Western blotting of the anti-microphthalmia-associated transcription factor and anti-Tyrosinase antibodies. β-actin was used as the loading control. The result shown are expressed as a mean value ± standard error of the mean of three independent experiments and the data were analyzed by one-way analysis of variance followed by post hoc Tukey's test. (*P < 0.05, **P < 0.01 and ***P < 0.001 vs. control group).