The Effect Of Tetramethylpyrazine And Diammonium Glycyrrhizinate On The Proliferation And Type I And Ⅲ Procollagen MRNA Expressions In Leloid Fibroblasts In Vitro

Background:Keloid is a benign fibrous growth that occur after trauma or wounding of the skin and present a major therapeutic dilemma to the dermatologists because of frequent recurrences.fibroblast isolated from keloid tissue and maintained in cell culture continue to express an increased capacity to proliferate and to produce collagen. Nowdays,one of the focus problems of keloid is how to inhibit these actions of KFB.then find effective ways to treat keloid . Tetramethylpyrazine(TMP) and Diammonium Glycyrrhizinate(DG) are Chinese traditional medicines which can improve blood circulation effectively.They are used to treat fibrosis diseases such as pulmonary fibrosis^ kidney fibrosis widely. There are few reports on their function on keloid and KFB.Objective: To investigate the effects of Tetramethylpyrazine (TMP) and Diammonium Glycyrrhizinate(DG) on keloid fibrobla-sts(KFB) proliferation and the mechanisms of inhibitory effects of TMP and DG on collagen sythesis in keloid-derived fibroblasts.Methods: Keloid fibroblasts were isolated from fresh keloid tissue and cultured .The KFB(from the 3rd to 9th passages)were treated with various concentrations of TMP and DG. Triamcinolone acetonide was used as a positive control, cell culture solution II as negative control.The effects of TMP and DG on KFB proliferation o was examined by MTT colorimetric cell proliferation assay. Dot Blot hybridization was used to detect type I and III procollagen mRNA expression in KFB.ResultcThe MTT results showed that TMP and DG at lower dose (O.lmg/ml > 0.25mg/ml , O.lmg/ml , 0.25mgmland0.5mg/ml respectively) after treating 24h, did not inhibited KFB proliferation significantly. (P>0.05);After treating 48h and 72h, both drugs showed significant inhibition effects(P<0.05,P<0.01 ).At higher dose(TMP 0.5mg/ml&l .Omg/ml, DG 1.0 mg/ml ), their signicant inhibition effects on KFB proliferation were observed at any detected time .To both drugs .there were correlation between the inhibition effect on KFB proliferation and not only the dose,but experiment time as well. The inhibition effects of TMP and DG on KFB proliferation is similar to that of triamcinolone acetonide (P>0.05) at 1.Omg/ml after 48h, 72h. Dot Blot hybridization Result indicated that TMP and DG both ruduced I and IIIprocollagen mRNA expressions significantly in the KFB(P<0.01).conclusion: TMP and DG inhibit KFB proliferation .and collagen synthesis at transcriptional level in vitro, there were correlation between the inhibition effect on KFB proliferation and not only the dose,but experiment time as well.The study still indicated that TMP and DG not only inhibited the growth of KFB but also may killed the cells at high dose.Postgraduate: Guo Haixia(dermatology) Directed by :Professor Wu Yanfang...