Special Centre for Molecular Medicine, Jawaharlal Nehru Universitygrid.10706.30, New Delhi, India.
Department of Life Sciences, School of Natural Sciences, Shiv Nadar Universitygrid.410868.3, Greater Noida, Uttar Pradesh, India.
Antimicrob Agents Chemother. 2022 Dec 20;66(12):e0039222. doi: 10.1128/aac.00392-22. Epub 2022 Nov 14.
The emergence of Plasmodium falciparum resistance raises an urgent need to find new antimalarial drugs. Here, we report the rational repurposing of the anti-hepatitis C virus drug, alisporivir, a nonimmunosuppressive analog of cyclosporin A, against artemisinin-resistant strains of P. falciparum. docking studies and molecular dynamic simulation predicted strong interaction of alisporivir with Cyclophilin 19B, confirmed through biophysical assays with a value of 354.3 nM. Alisporivir showed potent antimalarial activity against chloroquine-resistant (RKL-9 with resistance index [Ri] 2.14 ± 0.23) and artemisinin-resistant (Kelch13 with Ri 1.15 ± 0.04) parasites. The Ri is defined as the ratio between the IC values of the resistant line to that of the sensitive line. To further investigate the mechanism involved, we analyzed the expression level of Cyclophilin 19B in artemisinin-resistant P. falciparum (Kelch13). Semiquantitative real-time transcript, Western blot, and immunofluorescence analyses confirmed the overexpression of Cyclophilin 19B in Kelch13. A 50% inhibitory concentration in the nanomolar range, together with the targeting of Cyclophilin 19B, suggests that alisporivir can be used in combination with artemisinin. Since artemisinin resistance slows the clearance of ring-stage parasites, we performed a ring survival assay on artemisinin-resistant strain Kelch13 and found significant decrease in parasite survival with alisporivir. Alisporivir was found to act synergistically with dihydroartemisinin and increase its efficacy. Furthermore, alisporivir exhibited antimalarial activity . Altogether, with the rational target-based Repurposing of alisporivir against malaria, our results support the hypothesis that targeting resistance mechanisms is a viable approach toward dealing with drug-resistant parasite.
疟原虫耐药性的出现迫切需要寻找新的抗疟药物。在这里，我们报告了抗丙型肝炎病毒药物阿利司匹韦的合理再利用，它是环孢菌素 A 的非免疫抑制剂类似物，可对抗青蒿素耐药的疟原虫株。 对接研究和分子动力学模拟预测阿利司匹韦与环孢素 19B 有强烈的相互作用，通过与 值为 354.3 nM 的生物物理测定得到证实。阿利司匹韦对氯喹耐药（RKL-9 的耐药指数 [Ri] 为 2.14±0.23）和青蒿素耐药（Kelch13 的 Ri 为 1.15±0.04）寄生虫均具有强大的抗疟活性。Ri 定义为耐药株与敏感株的 IC 值之比。为了进一步研究所涉及的机制，我们分析了青蒿素耐药的疟原虫（Kelch13）中环孢素 19B 的表达水平。半定量实时转录、Western blot 和免疫荧光分析证实了 Kelch13 中环孢素 19B 的过表达。在纳摩尔范围内达到 50%的抑制浓度，以及对环孢素 19B 的靶向作用，表明阿利司匹韦可与青蒿素联合使用。由于青蒿素耐药会减缓环状阶段寄生虫的清除速度，我们对青蒿素耐药株 Kelch13 进行了环状存活试验，发现阿利司匹韦可显著降低寄生虫的存活率。阿利司匹韦与二氢青蒿素表现出协同作用，提高了其疗效。此外，阿利司匹韦还表现出抗疟活性。总的来说，通过基于合理的靶向机制对阿利司匹韦进行抗疟再利用，我们的结果支持了靶向耐药机制是应对耐药寄生虫的可行方法的假设。
