Protective effects of aucubin isolated from Eucommia ulmoides against UVB-induced oxidative stress in human skin fibroblasts.

Ultraviolet-B (UVB) irradiation has been demonstrated to produce reactive oxygen species (ROS) in the cells and skin, which induces the synthesis of matrix metalloproteinases (MMPs), causing skin photoaging. Using the human skin fibroblast HS68 cell line in the present study, we investigated the photoprotective effects of aucubin from Eucommia ulmoides. Pretreatment with aucubin significantly inhibited the production of MMP-1 by 57% when compared to the UVB-irradiated cells. Additionally, the senescence-associated beta-galactosidase (SA beta-gal) activity was markedly decreased in the presence of aucubin, which indicates it as an antiphoto-induced aging compound. As the effect of aucubin was determined against ROS, the inhibited ROS formation and malondialdehyde (MDA) levels, and the increased cell viability and glutathione (GSH) level were observed with aucubin under UVB irradiation. Based upon these results, it was suggested that aucubin might play an important role in the cellular defense mechanism against UV radiation-induced photoaging. An understanding of the antioxidant properties of aucubin could, in part, act to elucidate its protective mechanism on the human skin photoaging.