Chan Chi-Kong, Pan Guanrui, Chan Wan
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
J Mass Spectrom. 2021 Apr;56(4):e4652. doi: 10.1002/jms.4652. Epub 2020 Aug 31.
Houttuynia cordata (H. cordata) is a popular vegetable in Asian countries and is also used extensively as herbal medicine in treating various diseases. H. cordata contains aristolactams, which have a similar Chinese name as aristolochic acids (AAs); hence, an emerging concern in the greater China region has arisen about the potential linkage between H. cordata and aristolochic acid nephropathy (AAN). However, only a single study has tested for the presence of AAs in H. cordata samples, and the analysis was limited by the analytical sensitivity of the method. Thus, further analysis of AAs in H. cordata using analytical method of higher sensitivity is needed to alleviate public anxiety over the use of this popular vegetable. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to analyze H. cordata samples for the natural existence of aristolochic acid I (AA-I) and aristolochic acid II (AA-II), which are the most carcinogenic and nephrotoxic compounds in the AA family. After evaluating the method performance by fortifying blank samples with three concentrations of AAs, the validated method was applied to identify AA-I and AA-II in both fresh and sun-dried H. cordata samples (n = 20) collected from different cities in China. The LC-MS/MS method achieved method detection limits (MDLs) as low as 2 ng/g of AAs in H. cordata. Analysis of the collected fresh and sun-dried H. cordata samples revealed that AA-I and AA-II either do not exist naturally in H. cordata or exist at concentrations below the MDLs. Therefore, it is not very likely that consumption of H. cordata will result in AAN because AA-I and AA-II, the nephrotoxic and carcinogenic culprits of AAN, are not produced naturally in the plant or are produced at levels that do not pose a risk of AAN.
鱼腥草是亚洲国家一种受欢迎的蔬菜，还被广泛用作治疗各种疾病的草药。鱼腥草含有马兜铃内酰胺，其中文名与马兜铃酸（AAs）相似；因此，大中华地区对鱼腥草与马兜铃酸肾病（AAN）之间的潜在联系日益关注。然而，仅有一项研究检测了鱼腥草样本中马兜铃酸的存在情况，且该分析受到所用方法分析灵敏度的限制。因此，需要使用灵敏度更高的分析方法对鱼腥草中的马兜铃酸进行进一步分析，以缓解公众对这种受欢迎蔬菜使用的担忧。在本研究中，采用液相色谱 - 串联质谱（LC - MS/MS）方法分析鱼腥草样本中马兜铃酸I（AA - I）和马兜铃酸II（AA - II）的天然存在情况，这两种是马兜铃酸家族中最具致癌性和肾毒性的化合物。在用三种浓度的马兜铃酸强化空白样本评估方法性能后，将经过验证的方法应用于鉴定从中国不同城市采集的新鲜和晒干的鱼腥草样本（n = 20）中的AA - I和AA - II。LC - MS/MS方法在鱼腥草中实现了低至2 ng/g马兜铃酸的方法检测限（MDLs）。对采集的新鲜和晒干的鱼腥草样本分析表明，AA - I和AA - II要么在鱼腥草中天然不存在，要么以低于MDLs的浓度存在。因此，食用鱼腥草不太可能导致AAN，因为作为AAN肾毒性和致癌元凶的AA - I和AA - II并非在该植物中天然产生，或者产生的水平不会构成AAN风险。
