Abstract: This study evaluated the acute toxicity and genotoxicity of Niudali (Millettia speciosa roots) extracts. The limit method was used in acute toxicity test. The plate incorporation method was used in bacterial revert mutation test, and five strains of Salmonella typhimurium mutant strains TA97a, TA98, TA100, TA102 and TA1535 with histidine nutritional deficiency were counted back. The proportion of bone marrow polychromatic erythrocytes in total red blood cells and the proportion of micronucleus-containing polychromatic erythrocyte were counting in mammalian erythrocyte micronucleus test. Chromosomal aberration test was carried out through Chinese hamster lung (CHL) cell culture technology, the chromosome number and structural changes of CHL cell lines infected with samples were observed. The results showed that the tested samples were practically non-toxic, and the results of bacterial reversion mutation test, erythrocyte micronucleus test and chromosome aberration test were all negative. No acute toxicity or genotoxicity were observed within the dose range of this test for Niudali extracts.

Key words: Millettia speciosa root, acute toxicity, genetic toxicity

摘要： 本研究评价了牛大力提取物的急性毒性和遗传毒性。采用限量法进行急性毒性试验；采用平板掺入法，对有组氨酸营养缺陷的5株鼠伤寒沙门氏菌突变型菌株TA97a、TA98、TA100、TA102和TA1535进行回变菌落计数；经口灌胃法进行哺乳动物红细胞微核试验，计数骨髓嗜多染红细胞在总红细胞的比例及含微核嗜多染红细胞比率；采用中国仓鼠肺细胞(CHL)培养技术进行染色体畸变试验，观察受试样品牛大力提取物致CHL细胞株染色体数目及结构变化。结果显示，受试样品牛大力提取物属实际无毒级物质，细菌回复突变试验、红细胞微核试验、染色体畸变试验结果均为阴性。牛大力提取物在本试验剂量范围内未观察到急性毒性和遗传毒性。

关键词: 牛大力, 急性毒性, 遗传毒性