Parasitology Laboratory, Faculty of Medicine, Federal University of Rio Grande, Rio Grande, Brazil.
Synthesi Department, Institute of Drug Technology, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Parasitol Res. 2024 Jun 19;123(6):246. doi: 10.1007/s00436-024-08272-4.
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.
人体弓蛔虫病是一种具有全球分布的被忽视的人兽共患寄生虫病。治疗方法基于驱虫药物的使用；然而，它们在组织水平上的效果是低到中等的，这需要发现新的候选药物。包括香豆素衍生物在内的几组合成化合物已被证明对真菌、细菌甚至寄生虫具有生物活性，如中间指环虫、利什曼原虫和恶性疟原虫。本研究旨在评估十种香豆素衍生化合物对犬弓蛔虫幼虫的作用，采用体外、细胞毒性和计算方法筛选新的候选药物，用于评估治疗内脏弓蛔虫病的临床前试验。将化合物以 1mg/mL 的浓度进行两次重复的体外测试，具有杀幼虫活性的化合物进行连续稀释，以获得 0.5mg/mL；0.25mg/mL；0.125mg/mL；和 0.05mg/mL 的浓度。测试在含有 100 条犬弓蛔虫幼虫的 RPMI-1640 培养基的微量培养板中进行。选择一种化合物（COU 9）进行 J774.A1 鼠巨噬细胞的细胞毒性分析，结果发现该化合物在测试的任何浓度下均无细胞毒性。通过计算模型进行了计算机分析，该化合物表现出良好的口服生物利用度结果。为了确认幼虫的非存活状态，将微量培养板孔中的 COU 9 内容物接种到 7-8 周龄的雌性瑞士小鼠的腹腔内（IP）。这证实了该化合物对幼虫的杀幼虫活性。这些结果表明，COU 9 对犬弓蛔虫幼虫表现出杀幼虫活性，暴露于该化合物后，幼虫失去活力，并且 COU 9 抑制了小鼠模型中的感染。此外，COU 9 没有表现出细胞毒性，并且在计算机上具有足够的生物利用度，类似于阿苯达唑，这是治疗人类弓蛔虫病的首选药物，这支持了对 COU 9 进行未来调查和临床前测试的潜力。
