Tauheed Abdullah M, Mamman Mohammed, Ahmed Abubakar, Suleiman Mohammed M, Balogun Emmanuel O
Department of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Kaduna State, Nigeria.
Department of Pharmacognosy and Drug Development, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, Kaduna State, Nigeria.
Phytomed Plus. 2022 May;2(2). doi: 10.1016/j.phyplu.2022.100223. Epub 2022 Jan 15.
African trypanosomiasis is a protozoan disease with huge socio-economic burden to sub-Saharan African exceeding US$4.6 annual loss. To mitigate the incidence of trypanosomal drug resistance, efforts are geared towards discovery of molecules, especially from natural products, with potential to inhibit important molecular target (trypanosome alternative oxidase, TAO) in trypanosomes that are critical to their survival.
Crude methanol extract of was subjected to bioassay-guided antitrypanosomal assay to identify the most active extract with trypanocidal activity. The most active extract was run on a column chromatography yielding five fractions, F1-F5. The fractions were assayed for inhibitory effect on TAO. The most promising TAO inhibitor was subjected to antitrypanosomal evaluation by trypanosome count, drug incubation infectivity test (DIIT) and in vivo studies. Gas chromatography-mass spectrometry (GC-MS) was used to identify and quantify phytochemical constituents of the potential TAO-inhibiting fraction.
Ethyl acetate extract (EtOAc) significantly (<0.05) produced trypanocidal effect and was the most active extract. Of the five fractions, only F4 significantly (<0.05) inhibited TAO compared to the control. F4 completely immobilised the trypanosomes up to 0.5 μg/μl, yielding an EC of 0.024 μg/μl compared to the 0.502 μg/μl of diminazene aceturate positive control group. The DIIT showed that F4 was significantly (<0.05) potent up to 0.1 μg/μl. F4 significantly (<0.05) suppressed parasite multiplication in systemic circulation of the treated rats and significantly (<0.05) maintained high PCV when compared to the 5% DMSO group. Furthermore, F4 significantly (<0.05) lowered serum concentrations of malondialdehyde. Phytoconstituents identified by the GC-MS include tetradecene; cetene; 3-(benzylthio) acrylic acid, methyl ester; 1-octadecene; 9-heptadecanone; hexadecanoic acid, methyl ester; dibutyl phthalate; eicosene; octadecenoic acid, methyl ester; oleic acid; 2-methyl-Z,Z-3,13-octadecadienol; 1-docosene; 3-phenylthiane, s-oxide; phenol, 3-methyl; phthalic acid, di(2-propylpentyl) ester and 1,4-benzenedicarboxylic acid, bis (2-ethylhexyl) ester.
F4 from EtOAc contains six carbohydrates (9.58%), two free fatty acids (6.48%), five fatty acid esters (27.73%), two aromatic compounds (50.63%) and one organosulphide (5.61%). It inhibited TAO and demonstrated antitrypanosomal effects.
非洲锥虫病是一种原生动物疾病，给撒哈拉以南非洲地区带来了巨大的社会经济负担，每年损失超过46亿美元。为了降低锥虫耐药性的发生率，人们致力于发现具有抑制锥虫生存关键分子靶点（锥虫交替氧化酶，TAO）潜力的分子尤其是天然产物分子。
对[提取物名称未给出]的粗甲醇提取物进行生物测定导向的抗锥虫试验，以鉴定具有杀锥虫活性的最有效提取物。将最有效提取物进行柱色谱分离，得到五个馏分，F1 - F5。对这些馏分进行TAO抑制作用测定。通过锥虫计数、药物孵育感染性试验（DIIT）和体内研究对最有前景的TAO抑制剂进行抗锥虫评估。采用气相色谱 - 质谱联用（GC - MS）鉴定和定量潜在TAO抑制馏分的植物化学成分。
乙酸乙酯提取物（EtOAc）产生了显著（<0.05）的杀锥虫作用，是最有效的提取物。在五个馏分中，与对照组相比，只有F4显著（<0.05）抑制TAO。F4在浓度高达0.5μg/μl时能完全使锥虫固定，与乙酰氨基阿维菌素阳性对照组的0.502μg/μl相比，其半数有效浓度（EC）为0.024μg/μl。DIIT表明，F4在浓度高达0.1μg/μl时具有显著（<0.05）的效力。与5%二甲基亚砜组相比，F4显著（<0.05）抑制了治疗大鼠体循环中的寄生虫增殖，并显著（<0.05）维持了较高的红细胞压积。此外，F4显著（<0.05）降低了血清丙二醛浓度。通过GC - MS鉴定的植物成分包括十四碳烯；十六碳烯；3 -（苄硫基）丙烯酸甲酯；1 - 十八碳烯；9 - 十七烷酮；十六烷酸甲酯；邻苯二甲酸二丁酯；二十碳烯；十八碳烯酸甲酯；油酸；2 - 甲基 - Z,Z - 3,13 - 十八碳二烯醇；1 - 二十二碳烯；3 - 苯并噻吩，S - 氧化物；3 - 甲基苯酚；邻苯二甲酸二（2 - 丙基戊基）酯和1,4 - 苯二甲酸双（2 - 乙基己基）酯。
EtOAc中的F4含有六种碳水化合物（9.58%）、两种游离脂肪酸（6.48%）、五种脂肪酸酯（27.73%）、两种芳香化合物（50.63%）和一种有机硫化物（5.61%）。它抑制TAO并表现出抗锥虫作用。
