Simões-Silva M R, Nefertiti A S G, De Araújo J S, Batista M M, Da Silva P B, Bahia M T, Menna-Barreto R S, Pavão B P, Green J, Farahat A A, Kumar A, Boykin D W, Soeiro M N C
Laboratório de Biologia Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Laboratório de Doenças Parasitárias, Escola de Medicina & Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
Antimicrob Agents Chemother. 2016 Jul 22;60(8):4701-7. doi: 10.1128/AAC.01788-15. Print 2016 Aug.
The current treatment of Chagas disease (CD), based on nifurtimox and benznidazole (Bz), is unsatisfactory. In this context, we performed the phenotypic in vitro screening of novel mono- and diamidines and drug interaction assays with selected compounds. Ten novel amidines were tested for their activities against bloodstream trypomastigote (BT) and amastigote forms of Trypanosoma cruzi (Y and Tulahuen strains) and their toxicities for mammalian host cells (L929 cells and cardiac cells). Seven of 10 molecules were more active than Bz against BT, with the most active compound being the diamidine DB2267 (50% effective concentration [EC50] = 0.23 μM; selectivity index = 417), which was 28-fold more active and about 3 times more selective than the standard drug. Five of the six monoamidines were also more active than Bz. The combination of DB2267 and DB2236 in fixed-ratio proportions showed an additive effect (sum of fractional inhibitory concentrations < 4) on BT. Interestingly, when intracellular forms were exposed to DB2267, its activity was dependent on the parasite strain, being effective (EC50 = 0.87 ± 0.05 μM) against a discrete typing unit (DTU) II strain (strain Y) but not against a representative DTU VI strain (strain Tulahuen) even when different vehicles (β-cyclodextrin and dimethyl sulfoxide) were used. The intrinsic fluorescence of several diamidines allowed their uptake to be studied. Testing of the uptake of DB2236 (inactive) and DB2267 (active) by amastigotes of the Y strain showed that the two compounds were localized intracellularly in different compartments: DB2236 in the cytoplasm and DB2267 in the nucleus. Our present data encourage further studies regarding the activities of amidines and provide information which will help with the identification of novel agents for the treatment of CD.
基于硝呋莫司和苯并硝唑（Bz）的恰加斯病（CD）现有治疗方法并不理想。在此背景下，我们对新型单脒和双脒进行了体外表型筛选，并与选定化合物进行了药物相互作用测定。测试了10种新型脒对克氏锥虫（Y株和图拉温株）血流型锥鞭毛体（BT）和无鞭毛体形式的活性及其对哺乳动物宿主细胞（L929细胞和心肌细胞）的毒性。10种分子中有7种对BT的活性高于Bz，活性最高的化合物是双脒DB2267（50%有效浓度[EC50]=0.23μM；选择性指数=417），其活性比标准药物高28倍，选择性约高3倍。6种单脒中的5种也比Bz更具活性。DB2267和DB2236按固定比例组合对BT显示出相加作用（部分抑制浓度之和<4）。有趣的是，当细胞内形式暴露于DB2267时，其活性取决于寄生虫菌株，对离散型别单元（DTU）II株（Y株）有效（EC50=0.87±0.05μM），但对代表性的DTU VI株（图拉温株）无效，即使使用了不同的载体（β-环糊精和二甲基亚砜）。几种双脒的固有荧光使其摄取情况得以研究。对Y株无鞭毛体摄取DB2236（无活性）和DB2267（有活性）的测试表明，这两种化合物在细胞内定位于不同区室：DB2236在细胞质中，DB2267在细胞核中。我们目前的数据鼓励对脒的活性进行进一步研究，并提供有助于鉴定治疗CD新药物的信息。
