目的：建立体外抗癌天然药物筛选模型，评价丹参素的抗癌活性。方法：以遗传物质DNA为靶标，溴化乙锭（EB）为致癌物质，丹参素为试药，利用荧光光谱检测丹参素对EB-DNA体系的荧光猝灭效应；利用圆二色谱技术检测丹参素对EB-DNA体系的干扰作用。结果：丹参素能明显抑制EB-DNA体系的荧光强度，且具有浓度依赖性；丹参素能够有效阻断EB嵌入DNA的碱基对中，维持DNA分子的正常构象。结论：丹参素抑制致癌剂对DNA链的嵌合，从而起抗癌活性。该模型可应用于抗癌功效的天然药物的筛选中。

Objective: To establish in vitro screening model for natural anticancer drugs and evaluate the anticancer activity of denshensu on carcinogenic damaged DNA. Methods: Genetic material DNA was used as target, ethidium bromide (EB) as carcinogen, quenching effect of denshensu on fluorescence spectrum of EB-DNA was detected. Interfering effect of denshensu on circular dichroism spectra of EB-DNA was measured. Results: Denshensu strongly quenched the fluorescent intensity at a dose-dependent manner. The circular dichroism spectra showed that denshensu could inhibit the insertion of EB to base pairs of DNA, and maintain the normal conformation of DNA. Conclusion: Denshensu possesses strong anticancer activity by inhibiting insertion of carcinogens into genetic DNA. This model would be applicable for screening natural anticancer drugs

国家自然科学基金（30873400）; 国家重大新药创制专项资助（2009ZX09301）。