Abstract:

The study aimed to investigate the anti-aging and skin repair effects of madecassoside （MA） on D-galactose-induced skin aging mice. Mice were divided into 6 groups （n=12）: normal group （N）, model group （M）, low, medium, high-dose MA groups （L-MA, M-MA, H-MA） and high-dose MA+Nrf2 inhibitor ML385 group （H-MA+ML385）. The body weight, skin water content, antioxidant indicators （SOD, CAT, GSH-Px and MDA）, HYP and HA levels in skin tissue of mice in each group were detected. Skin histology was evaluated by HE staining. The transcript levels of MMP-1, MMP-3, Nrf2, Keap1 and HO-1 in skin tissues were detected by RT-qPCR. The protein expression levels of Nrf2, Keap1 and HO-1 in skin tissue were detected by Western blotting. The results show that compared with the M group, the skin water content of mice in L-MA group, M-MA group and H-MA group increases, the thickness of the epidermis and dermis increases, the skin structure is significantly improved, the levels of SOD, CAT and GSH-Px increase, the level of MDA decreases, the level of HYP and HA increases, the relative expression of MMP-1 and MMP-3 mRNA decreases, the relative expression of Nrf2 and HO-1 mRNA and protein increases, and the relative expression of Keap1 mRNA and protein decrease （P<0.05）. ML385 partially weakens the activation effect of MA on the Nrf2-HO-1 pathway, and weakens the anti-aging and skin repair effects of MA （P<0.05）. This study shows that MA has good anti-aging and skin repair effects, and its mechanism is related to the activation of Nrf2-HO-1 pathway.

Key words: madecassoside, anti-aging, skin repair, antioxidant, Nrf2-HO-1 pathway