Abstract:

Abstract:Objective To investigate the therapeutic effect of glycyrrhiza active substance on guinea pig model of vitiligo,and to clarify its mechanism on promoting synthesis of melanin,and to provide the basis for its clinical application.Methods Guinea pigs decolorized by H₂O₂ were used as experimental models,and normal control group was set up.After treatment of glycyrrhiza active substance in three doses groups(20,40,and 80mg·kg^-1),the therapeutic effect was observed by visual observation,macrography,histological examination as well as immunohistochemical study.Results The significant differences of skin color among control group,model group and treatment groups were observed by macrography.The total effective rates in 40 or 80 mg·kg^-1 groups were higher than that in control group (P<0.05 or P<0.01),and increased with the dose of glycyrrhiza active substance.Histological examination showed an evidently higher of melanin in basal cells,stratum spinosum and hair follicles in 40 or 80 mg·kg^-1 treatment groups compared with model group(P<0.01).Immunohistochemical results showed the expressions of HMB45 were higher in 40 or 80 mg·kg^-1 groups than that in model group (P<0.05 or P<0.01),and had dose-dependent relationship with glycyrrhiza active substance.Conclusion Glycyrrhiza active substance could increase the expression of HMB45 and promote synthesis of melanin,it shows certain efficacy in treatment of vitiligo,and it  can be used in treating vitiligo in clinic.

Key words: glycyrrhiza；vitiligo；models,animal