Figure 4.

Tart cherry regulates the activation of nuclear factor-kappa B (NF-κB) responsible for the keratinocyte apoptosis caused by PM₁₀. (A) Time-dependent response of PM₁₀ (100 μg/mL) on the activation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha (IκBα) and NF-κB in HaCaT cells as determined by Western blot. (B) The effect of tart cherry (TC, 200 μg/mL) on the phosphorylation of NF-κB is shown. (C,D) Cells pretreated with PD980529 (10 μM) and SB203580 (10 μM) as inhibitors for ERK and p38 MAPK were incubated with PM₁₀ for 30 min. (E) Representative immunofluorescence staining of NF-κB in cells co-treated with tart cherry and PM10 is shown. Scale bars, 100 μm (original magnification × 100). (F) Cells pretreated with Bay 11-7082 (10 μM) as an inhibitor for NF-κB were incubated with PM₁₀ for 24 h. Cell viability was determined. (A–F) Data are represented as the means ± S.E. n = 3. * p ≤ 0.01 vs. control. # p ≤ 0.05 vs. PM₁₀ alone. ROD, relative optical density.