Guo Xiaoqing, Zhang Suhui, Dial Stacey L, Boudreau Mary D, Xia Qingsu, Fu Peter P, Levy Dan D, Moore Martha M, Mei Nan
Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA.
Department of Pharmacology and Toxicology, Shanghai Institute for Food and Drug Control, Shanghai 201203, China.
Toxicol Res (Camb). 2014 Nov;3(6):487-496. doi: 10.1039/c4tx00053f. Epub 2014 Aug 11.
A 2-year cancer bioassay in rodents with a preparation of whole leaf extract administered in drinking water showed clear evidence of carcinogenic activity. To provide insight into the identity and mechanisms associated with mutagenic components of the extracts, we used the mouse lymphoma assay to evaluate the mutagenicity of the whole leaf extract (WLE) and decolorized whole leaf extract (WLD). The WLD extract was obtained by subjecting WLE to activated carbon-adsorption. HPLC analysis indicated that the decolorization process removed many components from the WLE extract, including anthraquinones. Both WLE and WLD extracts showed cytotoxic and mutagenic effects in mouse lymphoma cells but in different concentration ranges, and WLD induced about 3-fold higher levels of intracellular reactive oxygen species than WLE. Molecular analysis of mutant colonies from cells treated with WLE and WLD revealed that the primary type of damage from both treatments was largely due to chromosome mutations (deletions and/or mitotic recombination). The fact that the samples were mutagenic at different concentrations suggests that while some mutagenic components of WLE were removed by activated carbon filtration, components with pro-oxidant activity and mutagenic activity remained. The results demonstrate the utility of the mouse lymphoma assay as a tool to characterize the mutagenic activity of fractionated complex botanical mixtures to identify bioactive components.
在啮齿动物中进行的一项为期两年的癌症生物测定显示，用全叶提取物制剂通过饮用水给药具有明显的致癌活性证据。为了深入了解提取物诱变成分的特性和相关机制，我们使用小鼠淋巴瘤试验来评估全叶提取物（WLE）和脱色全叶提取物（WLD）的诱变性。WLD提取物是通过将WLE进行活性炭吸附获得的。高效液相色谱分析表明，脱色过程从WLE提取物中去除了许多成分，包括蒽醌。WLE和WLD提取物在小鼠淋巴瘤细胞中均显示出细胞毒性和诱变作用，但作用浓度范围不同，且WLD诱导的细胞内活性氧水平比WLE高约3倍。对用WLE和WLD处理的细胞的突变菌落进行分子分析表明，两种处理造成的主要损伤类型很大程度上是由于染色体突变（缺失和/或有丝分裂重组）。样品在不同浓度下具有诱变性这一事实表明，虽然WLE的一些诱变成分通过活性炭过滤被去除，但具有促氧化活性和诱变活性的成分仍然存在。结果证明了小鼠淋巴瘤试验作为一种工具在表征分级复杂植物混合物的诱变活性以鉴定生物活性成分方面的实用性。
