Jarerattanachat Viwan, Boonarkart Chompunuch, Hannongbua Supa, Auewarakul Prasert, Ardkhean Ruchuta
NSTDA Supercomputer Center, National Electronics and Computer Technology Center, National Science and Technology Development Agency, Pathumthani, 12120, Thailand.
Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
J Tradit Complement Med. 2022 Dec 7;13(1):1-10. doi: 10.1016/j.jtcme.2022.12.002. eCollection 2023 Jan.
Dengue is a potentially deadly tropical infectious disease transmitted by mosquito vector with no antiviral drug available to date Dengue NS5 protein is crucial for viral replication and is the most conserved among all four Dengue serotypes, making it an attractive drug target. Both Ginseng and Notoginseng extracts and isolates have been shown to be effective against various viral infections yet against Dengue Virus is understudied. We aim to identify potential inhibitors against Dengue NS5 Methyl transferase from small molecular compounds found in Ginseng and Notoginseng.
A molecular docking model of Dengue NS5 Methyl transferase (MTase) domain was tested with decoys and then used to screen 91 small molecular compounds found in Ginseng and Notoginseng followed by Molecular dynamics simulations and the per-residue free energy decompositions based on molecular mechanics/Poisson-Boltzmann (generalised Born) surface area (MM/PB(GB)SA) calculations of the hit. ADME predictions and drug-likeness analyses were discussed to evaluate the viability of the hit as a drug candidate. To confirm our findings, studies of antiviral activities against RNA and a E protein synthesis and cell toxicity were carried out.
The virtual screening resulted in Isoquercitrin as a single hit. Further analyses of the Isoquercitrin-MTase complex show that Isoquercitrin can reside within of the NS5 Methyl Transferase active sites; the AdoMet binding site and the RNA capping site. The Isoquercitrin is safe for consumption and accessible on multikilogram scale. studies showed that Isoquercitrin can inhibit Dengue virus by reducing viral RNA and viral protein synthesis with low toxicity to cells (CC > 20 μM). Our work provides evidence that Isoquercitrin can serve as an inhibitor of Dengue NS5 protein at the Methyl Transferase domain, further supporting its role as an anti-DENV agent.
登革热是一种由蚊媒传播的潜在致命热带传染病，目前尚无抗病毒药物。登革热NS5蛋白对病毒复制至关重要，且在所有四种登革热血清型中最为保守，使其成为一个有吸引力的药物靶点。人参和三七的提取物及分离物已被证明对多种病毒感染有效，但对登革热病毒的研究较少。我们旨在从人参和三七中发现的小分子化合物中鉴定出针对登革热NS5甲基转移酶的潜在抑制剂。
用诱饵测试登革热NS5甲基转移酶（MTase）结构域的分子对接模型，然后用于筛选人参和三七中发现的91种小分子化合物，接着进行分子动力学模拟以及基于分子力学/泊松-玻尔兹曼（广义玻恩）表面积（MM/PB(GB)SA）计算的命中物的每个残基自由能分解。讨论了ADME预测和类药性质分析，以评估命中物作为药物候选物的可行性。为了证实我们的发现，进行了针对RNA的抗病毒活性、E蛋白合成和细胞毒性的研究。
虚拟筛选得到异槲皮苷作为唯一命中物。对异槲皮苷-MTase复合物的进一步分析表明，异槲皮苷可位于NS5甲基转移酶活性位点内；AdoMet结合位点和RNA封端位点。异槲皮苷食用安全，可大量获取。研究表明，异槲皮苷可通过减少病毒RNA和病毒蛋白合成来抑制登革热病毒，对细胞毒性低（CC>20μM）。我们的工作提供了证据，证明异槲皮苷可作为登革热NS5蛋白甲基转移酶结构域的抑制剂，进一步支持其作为抗登革热病毒剂的作用。
