目的 探讨黄芩苷-金属（钇、镧、铈，Y³⁺、La³⁺、Ce³⁺）配合物（baicalin-metal complexes，BMC）与肝癌细胞DNA结合能力的强弱。方法 以提取的SMMC-7721肝癌细胞DNA为靶点，采用循环伏安法和交流阻抗法研究BMC与DNA的相互作用，探讨二者的作用机制。结果 BMC与肝癌细胞DNA通过静电作用形成非电活性超分子化合物，结合数（m）为1，结合常数（β_BC）为1.27×10⁵ L/mol、β_BC-Y为3.46×10⁵ L/mol、β_BC-La为6.24×10⁵ L/mol、β_BC-Ce为7.29×10⁶ L/mol，黄芩苷（BC）与金属离子配位后与DNA的结合能力明显增强，强弱顺序：BC-Ce >BC-La >BC-Y >BC。结论 BMC进入细胞后与DNA结合，阻滞DNA的复制，抑制细胞增殖，促进细胞凋亡，进而表现出抗肿瘤活性。BMC与DNA结合能力与其细胞毒性一致，具有关联性。

Objective The correlation of baicalin-metal (Y³⁺, La³⁺, and Ce³⁺) complexes (BMC) anti-tumor activity and the interactional ability of BMC binding with hepatoma SMMC-7721 cell DNA was investigated. Methods Hepatoma SMMC-7721 cells DNA was extracted as a target, cyclic voltammetry and AC impedance were utilized to study the interaction between BMC and DNA, and the interaction mechanism between BMC and DNA was explored. Results BMC and hepatoma SMMC-7721 cell DNA formed a non-electroactive supramolecular compounds through mixed-mode of electrostatic interaction, binding number m=1, binding constant β_BC=1.27×10⁵ L/mol, β_BC-Y=3.46×10⁵ L/mol, β_BC-La=6.24×10⁵ L/mol, and β_BC-Ce=7.29×10⁶ L/mol. After BC binding with metal ions, its ability of binding to DNA significantly enhanced, and the strength order:BC-Ce >BC-La >BC-Y >BC. Conclusion The ability of BMC binding with DNA consists with its cytotoxicity. After BMC binding with SMMC-7721 cell DNA, it could inhibit the cell proliferation and lead to the cell apoptosis, which illustrates the BMC exhibits an anti-tumor activity. The relevant results have given a reference for the study on the new anti-tumor complexes of Chinese materia medica.

国家自然科学基金资助项目（20877072）；浙江省科技计划资助项目（2010C33070）