Cortes-Morales J A, Olmedo-Juárez A, Trejo-Tapia G, González-Cortazar M, Domínguez-Mendoza B E, Mendoza-de Gives P, Zamilpa A
Departamento de Biotecnología, Centro de Desarrollo de Productos Bióticos, Instituto Politécnico Nacional, PO Box 24, Yautepec, Morelos, C.P. 62730, Mexico; Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social, Argentina No. 1. Col. Centro, CP 62790, Xochitepec, Morelos, Mexico.
Centro Nacional de Investigación Disciplinaria en Parasitología Veterinaria (CENID PAVET-INIFAP), Carretera Federal Cuernavaca-Cuautla No. 8534 / Col, Progreso, A.P. 206-CIVAC, C.P. 62550, Jiutepec, Morelos, Mexico.
Exp Parasitol. 2019 Feb;197:20-28. doi: 10.1016/j.exppara.2019.01.003. Epub 2019 Jan 8.
The indiscriminate use of chemical drugs to deworm livestock tends to trigger an anthelmintic resistance problem. In this context, the use of plant extracts rich in secondary metabolites could be an alternative method for the control of gastrointestinal nematodes. Baccharis conferta Kunth is a native plant species from Mexico that is widely used by several ethnic groups as forage for farm animals and medicinally to treat gastrointestinal diseases such as acute stomach ache, dysentery, diarrhoea, vomiting, indigestion, colic, intestinal spasms, urinary problems, and cramps. The aim of the present study was to isolate and characterise the ovicidal constituents of B. conferta and to determine a possible mode of action against Haemonchus contortus. The ovicidal activity was determined using the egg hatching inhibition test (EHI) to assess the methanol extract obtained from B. conferta foliage. The dry extract was partitioned (water/ethyl acetate) to obtain an ethyl acetate (BcEtOAc-F) and aqueous fraction. BcEtOAc-F showed an ovicidal activity of 72.32% EHI at 1 mg/mL. The chromatographic fractionation of BcEtOAc-F resulted in three active sub-fractions with higher ovicidal activity: BcC1R4 (99.15% EHI at 1.0 mg/mL); BcC1R5 (92.51% EHI at 0.75 mg/mL); and BcC1R8 (96.8% EHI at 3.0 mg/mL). Chemical analysis of the BcC1R4 fraction allowed the identification of the major active compound, isokaempferide (1, 98.06% EHI at 1 mg/mL). While, 4,5-di-O-acid caffeoylquinic (3; 96.8% EHI at 3 mg/mL) and an inactive flavone (vicenin-2, 2) were identified as the main compounds in BcC1R8. Chemical characterisation of the isolated compounds was performed via spectroscopic (NMR) and spectrometric (UPLC-MS) analyses. Additionally, the environmental and confocal scanning microscopy analyses revealed that isokaempferide was able to cross the eggshell layer without breaking it and attach itself to the embryo, causing its death. The flavonol, isokaempferide, and the hydroxycinamic acid, 4,5-di-O-caffeoylquinic, displayed powerful ovicidal effects, proving to be a potential alternative for the development of a phytodrug for the control of haemonchosis.
不加区分地使用化学药物给牲畜驱虫往往会引发抗驱虫药问题。在此背景下，使用富含次生代谢物的植物提取物可能是控制胃肠道线虫的一种替代方法。孔叶酒神菊是一种原产于墨西哥的植物物种，多个民族广泛将其用作农场动物的饲料，并用于治疗胃肠道疾病，如急性胃痛、痢疾、腹泻、呕吐、消化不良、绞痛、肠痉挛、泌尿系统问题和抽筋。本研究的目的是分离和鉴定孔叶酒神菊的杀卵成分，并确定其对捻转血矛线虫可能的作用方式。使用卵孵化抑制试验（EHI）来测定孔叶酒神菊叶片甲醇提取物的杀卵活性。将干燥提取物进行分配（水/乙酸乙酯），得到乙酸乙酯部分（BcEtOAc - F）和水相部分。BcEtOAc - F在1mg/mL时显示出72.32%的杀卵活性（EHI）。对BcEtOAc - F进行色谱分离得到三个杀卵活性更高的活性亚组分：BcC1R4（在1.0mg/mL时杀卵活性为99.15% EHI）；BcC1R5（在0.75mg/mL时杀卵活性为92.51% EHI）；以及BcC1R8（在3.0mg/mL时杀卵活性为96.8% EHI）。对BcC1R4组分的化学分析确定了主要活性化合物异山柰苷（1，在1mg/mL时杀卵活性为98.06% EHI）。而4,5 - 二 - O - 酰基咖啡酰奎宁酸（3；在3mg/mL时杀卵活性为96.8% EHI）和一种无活性的黄酮（异荭草苷 - 2，2）被确定为BcC1R8中的主要化合物。通过光谱（NMR）和光谱测定（UPLC - MS）分析对分离出的化合物进行化学表征。此外，环境和共聚焦扫描显微镜分析表明，异山柰苷能够穿过卵壳层而不破坏它，并附着在胚胎上，导致其死亡。黄酮醇异山柰苷和羟基肉桂酸4,5 - 二 - O - 咖啡酰奎宁酸显示出强大的杀卵作用，证明是开发用于控制血矛线虫病的植物药的潜在替代品。
