目的:研究五种中草药(鱼腥草、菊花、苍术、吴茱萸和麻黄)在体外模拟人体胃液条件下,阻断亚硝胺的合成和清除亚硝酸盐的能力。方法:采用分光光度法和紫外光解法测定五种中草药对亚硝胺合成的阻断率和对亚硝酸盐的清除率。结果:鱼腥草、菊花、苍术、吴茱萸和麻黄均具有一定阻断亚硝胺合成和清除亚硝酸盐的能力,其能力以吴茱萸最强,麻黄次之,鱼腥草最弱。结论:这五种中草药中都含有阻断亚硝胺合成和清除亚硝酸盐的活性成分,吴茱萸极有可能是一种经济、高效的防癌天然保健品新资源。 Objective: To study the ability of five Chinese herbal medicines (Houttuynia cordata, chrysanthemum, herb, Evodia, and Ephedra) to block the synthesis of nitrosamines and remove nitrite under simulated human gastric juice in vitro. Methods: The blocking rate of nitrosamine synthesis and the clearance rate of nitrite by five Chinese herbal medicines were determined by spectrophotometry and ultraviolet photolysis. Results: Houttuynia cordata, chrysanthemum, herb, Wusong and ephedra all had certain ability to block the synthesis of nitrosamines and remove nitrite. Its ability was the strongest in Wusong, followed by ephedra, and Houttuynia were the weakest. Conclusion: These five Chinese herbal medicines contain active ingredients that block the synthesis of nitrosamines and remove nitrite. Wu Yan is very likely to be a new resource for cancer-free natural health products that is economical and highly effective.