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Background and aim: Dengue is a potentially deadly tropical infectious disease transmitted by mosquito vector Aedes aegypti 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. Experimental procedure: 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, in vitro studies of antiviral activities against RNA and a E protein synthesis and cell toxicity were carried out. Results and conclusion: The virtual screening resulted in Isoquercitrin as a single hit. Further analyses of the Isoquercitrin-MTase complex show that Isoquercitrin can reside within both 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. In vitro studies showed that Isoquercitrin can inhibit Dengue virus by reducing viral RNA and viral protein synthesis with low toxicity to cells (CC50 > 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.
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Introduction: Ivermectin, hydroxychloroquine (HQ), and darunavir/ritonavir are widely prescribed as an oral treatment for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection despite their uncertainty of clinical benefit. The objective is to determine the safety and the efficacies of two treatment regimens against SARS-CoV-2 infection. Methods: We conducted an open-labeled, randomized, controlled trial to compare the efficacy between a 3-day course of once-daily high-dose oral ivermectin plus zinc sulfate (Group A) and a combination of HQ, darunavir/ritonavir, and zinc sulfate (HQ + antiretroviral, Group B) for 5 days in asymptomatic or mild SARS-CoV-2 infection. The study period was between December 2020 and April 2021. Results: Overall, 113 patients were randomized and analyzed (57 patients in Group A and 56 patients in Group B). The median duration to achieve the virological outcome of either undetected or cycle threshold (Ct) for N gene of SARS-CoV-2 by real-time polymerase chain reaction was 6 days (95% confidence interval [CI] 5.3-6.7) versus 7 days (95% CI: 5.4-8.6) in Group A and Group B, respectively (P = 0.419) in the modified intention-to-treat population. All patients were discharged from hospital quarantine as planned. Two patients in Group A and one patient in Group B were considered clinically worsening and received 10 days of favipiravir treatment. There was no serious adverse event found in both groups. Conclusion: We demonstrated that both treatment regimens were safe, but both treatment regimens had no virological or clinical benefit. Based on this result and current data, there is no supporting evidence for the clinical benefit of ivermectin for coronavirus-19.
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Microparticles (MPs) are vesicles that are released by budding from plasma membrane of living cells. Recently, the role of MPs in antiviral activity has been proposed. We investigated quantity and anti-influenza activity of MPs from human alveolar epithelial cells A549, human bronchial epithelial cells BEAS-2B, human colon adenocarcinoma cells HT-29, and the human lung fibroblast cells MRC-5. MPs were found from all four cell lines. However, anti-influenza activity against an H1N1 influenza virus was found only from MPs of A549 and BEAS-2B. BEAS-2B cell differentiation did not increase MP release. Methyl-ß-cyclodextrin (MßCD) increased MP release and anti-influenza activity in HT-29 and A549. MP release increased after calcium ionophore A23187 treatment in three cell lines but only in HT-29 after forskolin treatment. These findings provide in vitro data supporting the role of MPs as an innate defense against influenza virus and as an approach to enhance the defense.