Abstract:

The study aimed to reveal the whitening effect and antioxidant effect of isoastilbin （ISO）. In this study, a mouse model of skin photoaging （SP） induced by ultraviolet B （UVB） was established. Three doses （1, 2, 4 mg/cm²）of isoastilbin were administered transcutaneously in mice. After 8 weeks of treatment, the water content of mouse epidermis was detected. The morphology of epidermis and dermis was observed by HE staining and Masson trichrome staining. The levels of skin oxidative stress indicators （superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px） and malondialdehyde （MDA）） were measured according to the instructions of the kit. The content of melanin in skin was detected by NaOH lysis method. The activity of tyrosinase （TYR） in the skin was detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA levels of matrix metalloproteinase-1（MMP-1） and Collagen I were detected by RT-qPCT. The protein expression of nuclear factor E2-related factor 2 （Nrf2） in the skin cells was detected by Western blotting. The results show that isoastilbin increases the water content of epidermis, decreases the thickness of epidermis, reduces the degeneration of collagen fibers, decreases the relative expression of mRNA of MMP-1, increases the relative expression of mRNA of Collagen I, increases the activities of SOD, CAT and GSH-Px, decreases the content of MDA, increases the relative expression of nuclear Nrf2 and decreases the content of melanin and TYR in SP mice induced by UVB in a dose-dependent manner （P<0.05）. This study shows that isoastilbin can reduce UVB-induced SP in mice and has a whitening effect, which is related to the improvement of skin antioxidant capacity and the decrease of melanin content and TYR activity.

Key words: isoastilbin, ultraviolet B, whitening, antioxidation, skin photoaging, melanin, tyrosinase