Brazilian green propolis water extract up-regulates the early expression level of HO-1 and accelerates Nrf2 after UVA irradiation

BMC Complementary and Alternative Medicine

Research Article

Masamitsu Shimazawa¹  Yuichi Saito¹  Kazuhiro Tsuruma¹  Hideaki Hara¹  Kenji Ichihara² 

[1] Department of Biofunctional Evaluation, Molecular Pharmacology, Gifu Pharmaceutical University, 1-25-4 Daigakunishi, 501-1196, Gifu, Japan;Nagaragawa Research Center, Api.Co., Ltd., 692-3 Nagara, 502-0071, Gifu, Japan;

关键词: Propolis;    Nrf2;    HO-1;    Skin fibroblast;    UVA;   

DOI  :  10.1186/s12906-015-0945-4

 received in 2015-07-16, accepted in 2015-11-21,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundExposure to ultraviolet A (UVA) irradiation is the major cause of human skin aging. Suppression of UVA irradiation-induced skin fibroblast cell damage protects the skin against aging. An oxidative stress response transcription factor nuclear factor-(erythroid-derived 2)-related factor 2 (Nrf2) has an important role as a cytoprotective system against oxidative stress in the human skin and other organs. Propolis has been commonly used as a traditional medicine since ancient times. The water extract of propolis (WEP) mainly contains caffeoylquinic acids. In our previous study, we reported that WEP and its major constituents protected immortalized human skin fibroblast cells (NB1-RGB) against UVA irradiation-induced cell death. In this study, we examined the mechanism of WEP-mediated skin protection and the possible involvement of Nrf2/antioxidant response element (ARE) pathways.MethodsBrazilian green propolis was used in the present study (Minas Gerais State, Brazil), Baccharis dracunculifolia is its main source. The Baccharis propolis was extracted with water at 50 °C to yield water extract. The NB1-RGB cell cultures were incubated for 23 h. After replenishing the medium, WEP or its constituents were added to the cell cultures. After 1 h, the cells were exposed to 10 J/cm2 of UVA light (365 nm UVA light source, CL-1000 L UV Closslinkers, Ultraviolet Products Ltd., Cambridge, UK). Heme oxygenase-1 (HO-1) expression levels in NB1-RGB cells were evaluated using western blotting. Nrf2 nuclear translocation changes in NB1-RGB cells were indicated using immunostaining.ResultsWe demonstrated that WEP pretreatment up-regulated HO-1 expression level after UVA irradiation at earlier time points than vehicle pretreatment did, and three main constituents of WEP showed similar effects. Furthermore, WEP pretreatment also accelerated Nrf2 nuclear translocation after UVA irradiation.ConclusionsOur findings indicated that WEP acts as an early inducer of HO-1 and rapid activator of Nrf2 to protect against UVA-induced oxidative stress.

【 授权许可】

CC BY   
© Saito et al. 2015