Résumé
Objective To study the mechanism of anti-aging effect of dimethylaminoethanol (DMAE) and compound amino acid (AA) injection by mesotheray in D-galactose-induced skin aging rat.Methods Eighty rats were randomly divided into aging treatment group (60 cases),aging control group (10 cases) and normal control group (10 cases).The skin aging models were established by subcutaneous infectim of D-galactose.From the 18th day,the aging treatment group were injected intradermally in the rats' both sides hip skin with 0.2％ DMAE+ AA,0.1％ DMAE+AA,0.2％DMAE,0.1％ DMAE,AA,and saline,once a week.After four weeks,HE,water content,superoxide dismutase (SOD) activity,hydroxyproline (HYP) and malondialdehyde (MDA) content were measured.Results Compared with the aging control group,the epidermal and the dermal thickness and the collagen area of rats skin' increased significantly in 0.2 ％ DMAE+ AA and 0.1％ DMAE+ AA treatment groups (P＜0.05).0.2％ DMAE+AA and 0.1 ％ DMAE+AA treatment groups also had higher SOD activity,HYP content and lower MDA content than other groups (P＜0.05),but no difference was noted among normal control group,0.2％ DMAE+AA and 0.1％ DMAE+AA group (P＞0.05).There were no differences in water content among groups (P＞0.05).Conclusions Intradermal injection with 0.1％ DMAE+ AA and 0.2 ％ DMAE+AA in aging rats may increase the epidermal and the dermal thickness and the collagen of rats skin' improve SOD activity,HYP content and decreased MDA content,indicating that it has ability to clear skin free radicals,enhance antioxidant capacity and skin collagen metabolism,and thus prevent skin aging.