FIGURE 5.

Capsaicin inhibits UVB-induced Erk phosphorylation in cultured fibroblasts. The fibroblasts were incubated with capsaicin (Cap) from 1 to 10 μM with or without UVB irradiation at 300 mW/m² for 5 min. (A) The protein lysates were collected for SDS-PAGE and Western blot using antibody against phosphorylated Erk (P-Erk at ∼40 and ∼42 kDa). Antibody against total Erk (T-Erk at ∼40 and ∼42 kDa) was used as a loading control (upper panel). The quantification of the blots was shown (lower panel). (B) Antibodies against phosphorylated c-Jun and total c-Jun were applied in Western blot. Antibody against α-tubulin was used as a loading control. PD98059 (10 μM) was used as a positive control here. (C) The fibroblasts were treated with capsaicin (1 μM) or PAF C-16 (1 μM) before UVB irradiation. The COL1, P-Erk, T-Erk, P-Jun, and T-Erk were determined (left panel) and qualified (right panel). Values are in percentage of change, or increase, or decrease, against control, in mean ± SD, n = 5, each with triplicate samples. *, p < 0.05; **, p < 0.01; ***, p < 0.001 compared with control (vehicle only); #, p < 0.05 and ##, p < 0.01 compared with corresponding group.