N异靛甲对培养的人类角朊细胞的作用

为了探讨Ｎ异靛甲治疗银屑病的作用机理，我们利用结晶紫染色光吸收、氨基已糖甙酯酶测定、氚胸腺嘧啶掺入、细胞直接计数及细胞分化过程形态学定量等方法研究了该药在不同浓度下对培养的人类角朊细胞增殖及分化的影响。结果显示该药浓度为１０－７ｍｏｌ／Ｌ和１０－８ｍｏｌ／Ｌ时对角朊细胞的增殖有抑制作用，浓度为１０－９ｍｏｌ／Ｌ时即无此作用，而浓度为１０－１０ｍｏｌ／Ｌ时对角朊细胞的分化仍有显著促进作用。这说明Ｎ异靛甲对角朊细胞增殖与分化均有影响，但以促进分化为主。提示该药的作用机理不同于一般细胞毒化疗药物。

The Effects of N methylisoindigotin on Cultured Human Keratinocytes

N methylisoindigotin is a second generation drug developed on the basis of chemical structure and activity relationship studies of the compounds derived from a traditional Chinese medicinal herb Indigofera tinctoria which has been shown to be effective in treating psoriasis in clinical trials. To research into the therapeutic mechanism of the drug in the treatment of psoriasis, the authors using the methods of crystal violet staining, hexosaminidase assay, thymidine incorporation, cell counting and quantitation of morphologic changes during differentiation, studied the effects of N methylisoindigotin on cultured human keratinocytes. The results showed that N methylisoindigotin inhibited proliferation of keratinocytes at the concentrations of 10 -7 mol/L and 10 -8 mol/L but did not inhibit anymore at 10 -9 mol/L. However, the drug significantly promoted differentiation of keratinocytes even at 10 -10 mol/L. This indicates that N methylisoindigotin influences both the proliferation and the differentiation of keratinocytes and predominantly on the promotion of differentiation, suggesting the drug acts in a way different from that of ordinary cytotoxics in chemotherapy.