Résumé
Objective To investigate the therapeutic effect of licorice zinc on melasma.Methods Thirty-six BALB/c mice were equally divided into blank group,model group,licorzinc low-dose group,licorzine medium-dose group,licorzinc high-dose group and tranexamic acid group.Melasma was induced by 100 mJ/cm2 UVB irradiation combined with 15 mg/kg progesterone injection.Mice were treated with tranexamic acid(0.065 g/kg)and low(0.65 g/kg),medium(1.3 g/kg),or high(2.6 g/kg)doses of zinc licorice for 14 days.Skin was taken for HE and Masson-Fontana staining and measurement of SOD,MDA,GSP-Px,TNF-α,IL-1β,IL-6,plasma protein Nrf-2,nuclear protein Nrf-2 and HO-1 expression levels.Results Compared with model group,high-dose licorice zinc group showed decreased melanocyte formation,collagen cell necrosis,and inflammatory infiltration(P＜0.01);decreased MDA,IL-6,IL-1β,TNF-α and plasma protein Nrf-2 expression(P＜0.01);and increased GSP-Px,SOD and nuclear protein Nrf-2 and HO-1 expression(P＜0.01).Conclusions Zinc licorice activates the Nrf-2/HO-1 pathway to initiate high expression of HO-1,SOD and GSP-Px and fight oxidative stress,thereby reducing melanogenesis.