Effects Of Intradermal Injection Of Dimethylaminoethanol Compound Preparation On Skin Collagen Metabolism And Expression Of Related Pathways In Aging Rats

Objective: We designed this study to evaluate the effects of a new Dimethylaminoethanol compound agent administered intradermally by Mesotherapy on TGFβ1/smadspathway.Methods: 30 male rats were randomly allocated to three groups(treatment group、D-gal aging model group、normal group); each group had ten rats. treatment group, D-gal aging model group were subcutaneously injected with D- galactose prepared in normal saline 125mg﹒kg-1﹒d-1 for 42 day.Normal groups were injected with normal saline for 42 d with same method and dose. From the 18 th day, after shaving their hair,the treatment groups were injected this new Dimethylaminoethanol compound agent at a dose of 1ml per week for 4 weeks in the Dermis of two sides hip skin mark zone.Meanwhile, the ageing group were administrated the same volume of normal saline with same method. In vivo skin collagen alterations were investigated by Re?ectance Confocal Microscopy. Skin specimens were obtained 3days after the last treatment. In order to measure the dermal collagen density and dermal thickness, HE and Masson-trichrome staining were performed, respectively. Immunohistochemical staining for TGFβ1 and proliferating cell nuclear antigen(PCNA) were performed. Also, the level of TGFβ1, Smad3, Type I,III Pro-collagen,MMP-1,TIMP-1 m RNA expressions were assessed by Real-time quantitative polymerase chain reaction.Results:As revealed by RCM, in treatment group collagen density increasedgradually after treatment, while in ageing group it decreased as time went. Measurement of dermal thickness, dermal collagen density and hydroxyproline content in treatment group increased significantly than D-gal aging model group rats. The expressions of TGF-β1 in ageing group and treatment group were significantly lower than that of control group. But, the expression of treatment group elevated over that of ageing group with significant difference. The differences of PCNA,MMP-1 m RNA and type III Pro-collagen m RNA expression between ageing and treatment groups was not significant. In addition, this new Dimethylaminoethanol compound agent significantly up-regulated the m RNA expression of TGFβ1, smad3, TIMP-1, Type I Pre-collagen.Consuclusions: This new Dimethylaminoethanol compound agents showed anti-ageing effects by activating collagen synthesis, eventually causing dermal thickening. Collagen synthesis induced by this new Dimethylaminoethanol compound agent was mediated by TGF-β1/Smad3 signaling pathway.