Department of Clinical Analysis and Biomedicine, Universidade Estadual de Maringá, Maringá, Paraná, Brazil.
Department of Technology, Universidade Estadual de Maringá, Umuarama, Paraná, Brazil.
Antimicrob Agents Chemother. 2018 Dec 21;63(1). doi: 10.1128/AAC.01097-18. Print 2019 Jan.
Paracoccidioidomycosis (PCM), caused by , is a systemic mycosis with granulomatous character and a restricted therapeutic arsenal. The aim of this work was to search for new alternatives to treat largely neglected tropical mycosis, such as PCM. In this context, the enzymes of the shikimate pathway constitute excellent drug targets for conferring selective toxicity because this pathway is absent in humans but essential for the fungus. In this work, we have used a homology model of the chorismate synthase (EC 4.2.3.5) from (CS) and performed a combination of virtual screening and molecular dynamics testing to identify new potential inhibitors. The best hit, CP1, successfully adhered to pharmacological criteria (adsorption, distribution, metabolism, excretion, and toxicity) and was therefore used in experiments. Here we demonstrate that CP1 binds with a dissociation constant of 64 ± 1 μM to recombinant chorismate synthase from and inhibits enzymatic activity, with a 50% inhibitory concentration (IC) of 47 ± 5 μM. As expected, CP1 showed no toxicity in three cell lines. On the other hand, CP1 reduced the fungal burden in lungs from treated mice, similar to itraconazole. In addition, histopathological analysis showed that animals treated with CP1 displayed less lung tissue infiltration, fewer yeast cells, and large areas with preserved architecture. Therefore, CP1 was able to control PCM in mice with a lower inflammatory response and is thus a promising candidate and lead structure for the development of drugs useful in PCM treatment.
球腔菌病(PCM)由引起,是一种具有肉芽肿特征和有限治疗手段的系统性真菌病。本研究旨在寻找新的替代方法来治疗被忽视的热带真菌病,如 PCM。在这种情况下,莽草酸途径的酶是赋予选择性毒性的极好药物靶点,因为该途径在人类中不存在,但对真菌至关重要。在这项工作中,我们使用了来自的分支酸合酶(CS)的同源模型,并结合虚拟筛选和分子动力学测试来识别新的潜在抑制剂。最佳命中物 CP1 成功符合药物标准(吸收、分布、代谢、排泄和毒性),因此在实验中使用。在这里,我们证明 CP1 与重组来自的分支酸合酶的解离常数为 64±1μM,并抑制酶活性,半数抑制浓度(IC)为 47±5μM。正如预期的那样,CP1 在三种细胞系中均无毒性。另一方面,CP1 降低了治疗小鼠肺部的真菌负荷,与伊曲康唑相似。此外,组织病理学分析表明,用 CP1 治疗的动物显示出较少的肺组织浸润、较少的酵母细胞和保留更多结构的大面积区域。因此,CP1 能够在小鼠中控制 PCM,炎症反应较低,因此是开发用于 PCM 治疗的药物的有前途的候选物和先导结构。