狗舌草总黄酮抗白血病活性成分分析及作用机制研究

Development of the novel and specific anti-cancer agents from traditional Chinese medicine has attracted a great deal of attention worldwide. The previous study indicate that Chinese herb Tephroseris kirilowii exhibits anti-leukemic activity. However, the effective constituents of T. kirilowii which exhibits anti-leukemic activity and possible molecular mechanism have not yet been explored. Our preliminary study showed that ethylacetate extract of T. kirilowii exhibits anti-leukemic activity, and Akt signal pathway may play a critical role. In this study, we will isolate and purify the compounds from active extract of T. kirilowii, and identify the structure of compounds which exhibits anti-leukemic activity by 1D, 2D-NMR and HPLC-DAD-MS as well as MTT assay. We will also investigate the effects of biological active compounds from T. kirilowii on apoptosis in human leukemia cells using flow cytometry, and elucidate the possible molecular mechanism of these compounds-induced apoptosis by Western blot, pharmacological inhibitor, as well as genetic approaches. Finally, the effect of these compounds on the tumor growth of U937 xenograft mouse model will be evaluated. Our studies will provide significant insights into the molecular mechanisms and support the potential application of biological active compounds of T. kirilowii in cancer chemotherapy and chemoprevention.

从资源丰富的传统中药中开发低毒、高效的抗癌药物越来越受到国内外学者的关注。研究报道，中草药狗舌草具有抗白血病功能，但狗舌草抗白血病作用活性成分及其作用机制尚待进一步研究。我们前期工作发现，狗舌草总黄酮可诱导白血病细胞凋亡，Akt去磷酸化和Mcl-1下调可能发挥重要作用。本项目拟采用现代分离方法和技术手段对狗舌草总黄酮进行系统的化学分离，结合1D、2D-NMR和HPLC-MS等技术鉴定单体化合物化学结构，采用MTT法确定狗舌草总黄酮抗白血病有效成分；流式细胞术研究狗舌草总黄酮及其有效成分对多种人白血病细胞凋亡的影响；Western Blot、药理抑制剂和分子克隆等手段研究并阐明狗舌草总黄酮及其有效成分抗白血病作用分子机制；最后采用裸鼠异种移植瘤模型研究其体内抗白血病效应。本研究将揭示狗舌草抗白血病的药效物质基础，阐明狗舌草抗白血病作用的分子机制及可能的作用靶点。

本研究旨在从传统中药狗舌草中开发出低毒、高效的抗白血病药物。我们前期工作发现，狗舌草总黄酮可诱导白血病细胞凋亡，Akt去磷酸化和Mcl-1下调可能发挥重要作用。本项目采用了现代分离方法和技术手段对狗舌草总黄酮进行系统的化学分离，结合1D、2D-NMR和HPLC-MS等技术目前鉴定出7个黄酮类单体化合物化学结构，采用MTT法确定Isorhamnetin为其中抗白血病最有效的成分；并用流式细胞术研究Isorhamnetin对多种人白血病细胞凋亡的影响；Western Blot、药理抑制剂和分子克隆等手段研究并阐明Isorhamnetin抗白血病作用分子机制；本研究将揭示狗舌草抗白血病的药效物质基础，阐明狗舌草抗白血病作用的分子机制及可能的作用靶点。