The Antiaging Activity of Ergothioneine in UVA-Irradiated Human Dermal Fibroblasts via the Inhibition of the AP-1 Pathway and the Activation of Nrf2-Mediated Antioxidant Genes

Figure 5

Effect of EGT on ARE promoter activation and subsequent expression of HO-1, NQO-1, and γ-GCLC proteins in HSF cells. (a) EGT stimulates Nrf2-mediated ARE activity. HSF cells were cotransfected with pGL3-ARE and treated with different concentrations of EGT (0.125-0.5 μM) for 2 h to measure the percentage of ARE promoter activity. Data were presented as fold over increase in the percentage of ARE promoter activity. (b, c) Effect of EGT concentration and the time of EGT exposure to HSF cells in the induction of antioxidant proteins. HSF cells were treated with different concentrations of EGT for 6 h (b) or 0.5 μM EGT for 1-8 h (c). These cells were harvested, and the expressions of HO-1, NQO-1, and γ-GCLC antioxidant proteins were determined by Western blot analysis. In these conditions, β-actin was used as an internal control. Relative changes in protein bands were measured by densitometry. (d) EGT upregulated the GSH production. HSF cells were incubated with different concentrations of EGT (0.125-0.5 μM) for 24 h. Intracellular total GSH content was measured by a commercially available ELISA kit, as described in Materials and Methods and was expressed in micromolar concentrations as compared to the untreated cells. Data were presented as of three or more experiments. Statistical significance was considered as as compared to untreated control cells.

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