Figure 1.

PT inhibits the cytokine release of HaCaT cells. (A) HaCaT cells were incubated in the absence (medium alone) or presence of PT extract at the indicated concentrations for 48 h. Survival rate was measured by performing MTT‑based viability assay. Data are presented as a mean ± SD of three independent experiments and expressed as a relative ratio to the absorbance of untreated cells, which was set at 100%d. (B) HaCaT cells were pretreated in the absence or presence of PT extract at the indicated concentrations. Cells were treated with 10 ng/mL IFN-γ and TNF-α for 24 h. The supernatant was collected and analyzed by using ELISA. Data are presented as the mean ± SD of three independent experiments with statistical significance as *P < 0.05 and **P < 0.01 between untreated and IFN-γ and TNF-α-treated groups or between the IFN-γ and TNF-α-treated group and the PT‑treated group.