Figure 6.

Effect of SFE-EtOAc on the intracellular ROS levels and mRNA expression of antioxidant enzymes in HaCaT cells. HaCaT cells were pretreated with vehicle or SFE-EtOAc (30 μg/mL and 100 μg/mL) for 9 h and then stimulated with UVB (60 mJ/cm²). (a) Intracellular ROS generation was measured by relative fluorescence intensity using DCF-DA dye as indicated in Section 2. Data are shown as mean ± SD values (n = 3). **P < 0.01 compared with UVB-exposed group. (b) The mRNA levels of antioxidant enzymes such as catalase and Cu/Zn-SOD were measured by RT-PCR using their specific primers. Quantification data of mRNA expression of antioxidant enzymes analyzed by RT-PCR, which was normalized by GAPDH levels as loading control. Asterisks indicate a significant difference compared with UVB-irradiated group (**P < 0.01).