Protection of Bovine Mammary Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Cell Damage by Resveratrol

Figure 3

The cytoprotective effects of resveratrol against oxidative stress were dependent on the induction of Nrf2 in MAC-T cells. (a) Left panel: quantitative real-time PCR analysis of Nrf2 mRNA in MAC-T cells pretreated with or without resveratrol for 2 h and then treated with or without H₂O₂ for 0–24 h. (resveratrol group was compared with H₂O₂ control group at specified time points); (resveratrol + H₂O₂ group was compared with H₂O₂ control group at specified time points); Right panel: mRNA expression of Nrf2 in MAC-T cells pretreated with 0–50 µM of resveratrol for 2 h and then treated with (H₂O₂ group) or without (normal condition group) 500 µM of H₂O₂ for 8 h. The means with different superscripts are significantly different ( < 0.05). (b) Immunofluorescence staining of Nrf2 in MAC-T cells treated with or without resveratrol (RES) for 2 h or H₂O₂ for 8 h. DAPI staining was performed to stain the nucleus. Treatment of cells with tBHQ (50 µM) for 8 h served as a positive control for Nrf2 translocation. (c) mRNA expression of Nrf2, HO-1, TrxR-1, xCT, GRP78, and CHOP in MAC-T cells transfected with either a Nrf2 siRNA (Si-Nrf2-3) or a control siRNA (NC) for 12 h and with or without resveratrol pretreatment for 2 h followed by H₂O₂ treatment for additional 8 h. (d) Cell viability assay in MAC-T cells transfected with either a Nrf2 siRNA (Si-Nrf2-3) or a control siRNA (NC) and with or without resveratrol pretreatment for 2 h and subsequent H₂O₂ treatment for additional 12 h. Reported values are the means ± SD from three experiments, , , and .