School of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
Institute of Biosciences, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
PLoS One. 2019 Jan 25;14(1):e0211237. doi: 10.1371/journal.pone.0211237. eCollection 2019.
Plant extracts are a potential source of new compounds for nematode control and may be an excellent alternative for the control gastrointestinal nematodes that are resistant to conventional anthelmintics. However, research involving natural products is a complex process. The main challenge is the identification of bioactive compounds. Online analytical techniques with universal detectors, such as high-performance liquid chromatography-mass spectrometry (HPLC-MS), together with metabolomics could enable the fast, accurate evaluation of a massive amount of data, constituting a viable option for the identification of active compounds in plant extracts. This study focused on the evaluation of the ovicidal activity of ethanol extracts from 17 plants collected from the Pantanal wetland in the state of Mato Grosso do Sul, Brazil, against eggs of Haemonchus placei using the egg hatchability test. The ethanol extracts were obtained using accelerated solvent extraction. The data on ovicidal activity, mass spectrometry and metabolomics were evaluated using HPLC-DAD-MS, partial least squares regression analysis (PLS-DA) and a correlation map (univariate correlation analyses) to detect compounds that have a positive correlation with biological activity. Among the ten metabolites with the best correlation coefficients, six were phenylpropanoids, two were triterpene saponins, one was a brevipolide, and one was a flavonoid. Combinations of metabolites with high ovicidal action were also identified, such as phenylpropanoids combined with the triterpene saponins and the flavonoid, flavonoids combined with iridoid and phenylpropanoids, and saponins combined with phenylpropanoid. The positive correlation between classes of compounds in plants belonging to different genera and biological activity (as previously identified in the literature) reinforces the robustness of the statistical data and demonstrates the efficacy of this method for the selection of bioactive compounds without the need for isolation and reevaluation. The proposed method also enables the determination of synergism among the classes, which would be impracticable using traditional methods. The present investigation demonstrates that the metabolomic technique was efficient at detecting secondary metabolites with ovicidal activity against H. placei. Thus, the use of metabolomics can be a tool to accelerate and simplify bioprospecting research with plant extracts in veterinary parasitology.
植物提取物是一种控制线虫的新化合物的潜在来源，可能是对抗传统驱虫药耐药的胃肠道线虫的绝佳替代品。然而，涉及天然产物的研究是一个复杂的过程。主要的挑战是识别生物活性化合物。具有通用检测器的在线分析技术，如高效液相色谱-质谱联用（HPLC-MS），与代谢组学一起，可以快速、准确地评估大量数据，这是识别植物提取物中活性化合物的可行选择。本研究集中评估了来自巴西马托格罗索州潘塔纳尔湿地的 17 种植物的乙醇提取物对哈蒙科线虫虫卵的杀卵活性，使用卵孵化试验。乙醇提取物采用加速溶剂萃取法提取。使用高效液相色谱-二极管阵列检测-质谱（HPLC-DAD-MS）、偏最小二乘回归分析（PLS-DA）和相关图（单变量相关分析）评估杀卵活性、质谱和代谢组学数据，以检测与生物活性呈正相关的化合物。在与生物活性相关性最好的十个代谢物中，有六个是苯丙素，两个是三萜皂苷，一个是布瑞维波里德，一个是黄酮类化合物。还鉴定了具有高杀卵作用的代谢物组合，如苯丙素与三萜皂苷和黄酮类化合物组合，黄酮类化合物与环烯醚萜和苯丙素组合，以及皂苷与苯丙素组合。不同属植物中化合物类别的正相关性与生物活性（如文献中所述）增强了统计数据的稳健性，并证明了该方法用于选择生物活性化合物的有效性，而无需分离和重新评估。该方法还可以确定类之间的协同作用，这在使用传统方法时是不可行的。本研究表明，代谢组学技术能够有效地检测对 H. placei 具有杀卵活性的次生代谢物。因此，代谢组学的应用可以成为兽医寄生虫学中植物提取物生物勘探研究的一种工具，可以加速和简化这方面的研究。
