Abstract：
Human toxocariasis is a neglected anthropozoonosis with global distribution. Treatment is based on the administration of anthelmintics; however, their effectiveness at the tissue level is low to moderate, necessitating the discovery of new drug candidates. Several groups of synthetic compounds, including coumarin derivatives, have demonstrated bioactivity against fungi, bacteria, and even parasites, such as Dactylogyrus intermedius, Leishmania major, and Plasmodium falciparum. The aim of this study was to evaluate the effect of ten coumarin-derived compounds against Toxocara canis larvae using in vitro, cytotoxicity, and in silico tests for selecting new drug candidates for preclinical tests aimed at evaluating the treatment of visceral toxocariasis. The compounds were tested in vitro in duplicate at a concentration of 1 mg/mL, and compounds with larvicidal activity were serially diluted to obtain concentrations of 0.5 mg/mL; 0.25 mg/mL; 0.125 mg/mL; and 0.05 mg/mL. The tests were performed in a microculture plate containing 100 T. canis larvae in RPMI-1640 medium. One compound (COU 9) was selected for cytotoxicity analysis using J774.A1 murine macrophages and it was found to be non-cytotoxic at any concentration tested. The in silico analysis was performed using computational models; the compound presented adequate results of oral bioavailability. To confirm the non-viability of the larvae, the contents of the microplate wells of COU 9 were inoculated intraperitoneally (IP) into female Swiss mice at 7-8 weeks of age. This confirmed the larvicidal activity of this compound. These results show that COU 9 exhibited larvicidal activity against T. canis larvae, which, after exposure to the compound, were non-viable, and that COU 9 inhibited infection in a murine model. In addition, COU 9 did not exhibit cytotoxicity and presented adequate bioavailability in silico, similar to albendazole, an anthelmintic, which is the first choice for treatment of human toxocariasis, supporting the potential for future investigations and preclinical tests on COU 9.
摘要：
人类弓形虫病是一种全球分布的被忽视的人畜共患病。治疗是基于驱虫药的管理;然而，它们在组织水平上的有效性是低到中等的，有必要发现新的候选药物。几组合成化合物，包括香豆素衍生物,已经证明了对真菌的生物活性，细菌,甚至是寄生虫，例如Dactylogyrusintermedius，利什曼尼亚大调,和恶性疟原虫.这项研究的目的是评估十种香豆素衍生化合物对犬弓形虫幼虫的体外作用，细胞毒性，以及用于选择旨在评估内脏弓形虫病治疗的临床前测试的新药候选物的计算机模拟测试。化合物在1mg/mL的浓度下重复进行体外测试，和具有杀幼虫活性的化合物被连续稀释以获得0.5mg/mL;0.25mg/mL;0.125mg/mL;和0.05mg/mL的浓度。在RPMI-1640培养基中,在含有100头犬幼虫的微培养板中进行测试。选择一种化合物(COU9)用于使用J774的细胞毒性分析。A1鼠巨噬细胞,并且发现其在测试的任何浓度下都是非细胞毒性的。使用计算模型进行计算机模拟分析；该化合物具有足够的口服生物利用度结果。为了确认幼虫的无生存能力，将COU9的微孔板的内容物腹膜内（IP）接种到7-8周龄的雌性瑞士小鼠中。这证实了该化合物的杀幼虫活性。这些结果表明，COU9表现出针对犬T.canis幼虫的杀幼虫活性，which,暴露于化合物后，是不可行的，COU9抑制小鼠模型中的感染。此外,COU9没有表现出细胞毒性，并在计算机上表现出足够的生物利用度，类似于阿苯达唑，一种驱虫药,这是治疗人类弓形虫病的首选，支持COU9未来研究和临床前测试的潜力。
