Effects of Machilus thunbergii Sieb et Zucc on UV-induced photoaging in hairless mice.

Chronic ultraviolet (UV) exposure induces photoaging and oxidative stress in the skin. We investigated whether Machilus thunbergii Sieb et Zucc (M. thunbergii) could reduce UV-induced photoaging and oxidative stress in hairless mice. The dorsal skin of hairless mice was treated topically with M. thunbergii for 2 h prior to UV irradiation. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were then measured in skin and/or serum samples. Histological changes in the skin were assessed by hematoxylin-eosin (HE) staining. In addition, proteomes from the skin of hairless mice in each group were analyzed. The thickness of the dorsal skin and epidermis was significantly decreased by M. thunbergii treatment. We also found that MDA levels decreased after M. thunbergii treatment and the SOD levels were increased by M. thunbergii compared with those in the UV-only treated group. Proteomic analysis revealed 17 proteins associated with photoaging. These data indicate that M. thunbergii might have antiphotoaging effects.