Experimental Studies on the Inhibitory Effects of Yukmijiwhang-tang on Photoaging Skin Induced by UVB Irradiation

The purpose of this study is to investigate the protective effects of Yukmijiwhang-tang(YM) water extracts against the UVB irradiation on the human keratinocyte HaCaT cells. We observed the effects of YM on the oxidative stress, gene expression of pro-inflammatory cytokine such as TNF-α and IL-1β, and matrix metalloproteinase-9 in UVB-irradiated HaCaT cells. On the effects of oxidative stress and antioxidant function on the treatment with YM, The activity of xanthine oxidase(XO) was significantly decreased by treatment of YM in all the concentrations(p<0.01). The activity of superoxide dismutase(SOD) and catalase(CAT) was significantly increased by treatment of YM in a dose dependent manner(p<0.05 and p<0.01). DPPH radical was erased by treatment of YM under dose of 500 μg/ml concentration. Treatment of HaCaT cells with YM had also significantly reduced intracellular ROS produced by UVB irradiation in a dose dependent manner(p<0.05, p<0.01, p<0.001). Gelatin zymography assay showed that YM downregulated the MMP-9 activity in UVB-irradiated HaCaT cells. RT-PCR analysis revealed that YM suppressed the expression of IL-1β and MMP-9 however, it has no effects on the expression of TNF-α and MMP-3. Our study suggests that Yukmijiwhang-tang exert protective actions on the UVB-irradiated HaCaT cells largely by anti-oxidative and anti-inflammatory processes. keywords : Yukmijiwhang-tang, UVB, XO, SOD, CAT, DPPH, ROS, Gelatin Zymography, MMP-9, TNF-α, IL-1β