Photoaging Protective Effects of Ranunculus bulumei Methanol Extract

Figure 4

Effect of Rb-ME on the AP-1 signaling pathway in UV-irradiated HaCaT cells. (a) The promoter-binding activity of the transcription factor AP-1 was determined using a reporter gene assay. HEK293 cells were transfected with plasmids driving the expression of AP-1-Luc (1 μg/mL) and β-gal (as a transfection control) in the presence or absence of PMA (100 nM) and Rb-ME (50 or 100 μg/mL) for 24 h. (b) The effects of MAPK inhibitors (SB203580 (a p38 inhibitor, 20 μM), SP600125 (a JNK inhibitor, 20 μM), and U0126 (an ERK inhibitor, 20 μM)) on the mRNA levels of MMP-9 and COX-2 in UVB-irradiated HaCaT cells were determined by RT-PCR. (c) The protein levels of phospho- and total forms of JNK, ERK, p38, and β-actin in whole cell lysates of UV-irradiated HaCaT cells treated with or without Rb-ME (50 or 100 μg/mL) were determined by immunoblotting. compared to the normal group and compared to the control group.

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