Figure 5. UV absorption effect of the culture medium on IL-6 secretion. The HCE-2 cells (A) and HCECs (B) were irradiated in a colorless buffer solution or in a normal culture medium prior to change of medium without or with 100 μg/ml cis-UCA and were then followed for 24 h. An asterisk indicates p<0.05, and a double asterisk denotes p<0.001 (n=6 dishes). Abbreviations: C, control; m, medium; PBS, phosphate buffered saline; UCA, urocanic acid; UV, ultraviolet.