Figure 5.

Preventive effect of cis-UCA on the secretion of IL-1β and IL-18 in UV-B-stressed HCE cells. TNF-α–primed (10 ng/mL) HCE cells were pretreated with cis-UCA (100 µg/mL) for 1 hour followed by irradiation with UV-B (0.2 J/cm²). (A) Caspase-1 activity was measured from HCE-2 cell lysates by an enzymatic assay and (B) IL-1β levels from HCE-2 cell culture medium samples by the ELISA method at 24 hours after the UV-B exposure. Data for caspase-1 activity were combined from two independent experiments with three parallel samples per group, and data of IL-1β were combined from three independent experiments with 10 to 12 parallel samples per group in each experiment. The results were confirmed in primary HCE cells where the amounts of (C) IL-1β, (D) IL-18, and (E) LDH were measured. Levels of IL-1β (C) and LDH (E) were investigated from four donors with three (TNF-α) or two (UV-B, TNF-α + UV-B, TNF-α + cis-UCA + UV-B) parallel samples from each donor. (D) IL-18 was measured from two donors with two parallel samples from each donor. All data are shown as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ns = not significant, Mann-Whitney U-test.