Paeonol protects melanocytes against hydrogen peroxide-induced oxidative stress through activation of Nrf2 signaling pathway.

Oxidative stress plays a pivotal role in the pathogenesis of vitiligo. Paeonol, a phenolic compound found in the root bark of Cortex Moutan, has been suggested to have therapeutic effects on various diseases through nuclear factor Nrf2 mediated antioxidant pathways. However, the therapeutic effects of paeonol on vitiligo have not been investigated. In this study, we investigated whether paeonol could protect melanocytes against oxidative stress through Nrf2 activation. Hydrogen peroxide (H O ) was used to mimic the oxidative stress. PIG1 cells were pretreated with paeonol for 24 h, and then were treated with H O for 24 h. To detect the role of Nrf2, siRNA method was used to knockdown the Nrf2 expression. After that, cell viability, melanin content, tyrosinase activity, intracellular reactive oxygen species, antioxidant enzymes activities, nuclear translocation of Nrf2, and mRNA expression of Nrf2 downstream antioxidant genes were detected. Paeonol improved cell viability and melanogenesis in PIG1 cells treated with H O . Paeonol also alleviated oxidative stress by restoring the activities of superoxide dismutase, catalase, and glutathione peroxidase. Paeonol promoted Nrf2 nuclear translocation and the expression of its downstream-regulated antioxidative genes under oxidative stress. Furthermore, Nrf2 knockdown by siRNA abolished the protective effects of paeonol on PIG1 cells against oxidative damage. Paeonol protected melanocytes against H O -induced oxidative stress by Nrf2 mediated antioxidant pathways. Paeonol is a potential therapeutic drug for vitiligo.