Figure 6.
Effect of PPP on hydration in HDF. The cells were pretreated with PPP at the indicated concentration for 1 h, irradiated with UVB at 25 mJ/cm2, and further incubated for 24 h. (A) Hyaluronic acid was measured by ELISA assay. After incubation for 24 h, the cell supernatant was collected for measuring the extracellular hyaluronic acid content. (B–D) After incubation for 24 h, the cell lysate was harvested and used for total RNA extraction. The mRNA expression related to skin hydration was determined by quantitative real-time PCR. Statistical significance indicated * p < 0.05; ** p < 0.01; *** p < 0.001 compared with the untreated group.