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The recent outbreak of COVID-19 caused by SARS-CoV-2 brought a great global public health and economic concern. SARS-CoV-2 is an enveloped RNA virus, from the genus Betacoronavirus. Although few molecules have been tested and shown some efficacy against SARS-CoV-2 in humans but a safe and cost-effective attachment inhibitors are still required for the treatment of COVID-19. Natural products are gaining attention because of the large therapeutic window and potent antiviral, immunomodulatory, anti-inflammatory, and antioxidant properties. Therefore, this study was planned to screen natural products from Ayurveda that have the potential to modulate host immune system as well as block the virus entry in host cells by interfering its interaction with cellular receptor and may be used to develop an effective and broad-spectrum strategy for the management of COVID-19 as well as other coronavirus infections in coming future. To decipher the antiviral activity of the selected natural products, molecular docking was performed. Further, the drug-likeness, pharmacokinetics and toxicity parameters of the selected natural products were determined. Docking results suggest that curcumin and nimbin exhibits highest interaction with spike glycoprotein (MolDock score - 141.36 and - 148.621 kcal/mole) and ACE2 receptor (MolDock score - 142.647 and - 140.108 kcal/mole) as compared with other selected natural products/drugs and controls. Also, the pharmacokinetics data illustrated that all selected natural products have better pharmacological properties (low molecular weight; no violation of Lipinski rule of five, good absorption profiles, oral bioavailability, good blood-brain barrier penetration, and low toxicity risk). Our study exhibited that curcumin, nimbin, withaferin A, piperine, mangiferin, thebaine, berberine, and andrographolide have significant binding affinity towards spike glycoprotein of SARS-CoV-2 and ACE2 receptor and may be useful as a therapeutic and/or prophylactic agent for restricting viral attachment to the host cells. However, few other natural products like resveratrol, quercetin, luteolin, naringenin, zingiberene, and gallic acid has the significant binding affinity towards ACE2 receptor only and therefore may be used for ACE2-mediated attachment inhibition of SARS-CoV-2.
RESUMO
The emergence of 2019 novel coronavirus (2019-nCoV) is of global concern and might have emerged from RNA recombination among existing coronaviruses. CoV spike (S) protein which is crucial for receptor binding, membrane fusion via conformational changes, internalization of the virus, host tissue tropism and comprises crucial targets for vaccine development, remain largely uncharacterized. Therefore, the present study has been planned to determine the sequence variation, structural and antigenic divergence of S glycoprotein which may be helpful for the management of 2019-nCoV infection. The sequences of spike glycoprotein of 2019-nCoV and SARS coronavirus (SARS-CoV) were used for the comparison. The sequence variations were determined using EMBOSS Needle pairwise sequence alignment tools. The variation in glycosylation sites was predicted by NetNGlyc 1.0 and validated by N-GlyDE server. Antigenicity was predicted by NetCTL 1.2 and validated by IEDB Analysis Resource server. The structural divergence was determined by using SuperPose Version 1.0 based on cryo-EM structure of the SARS coronavirus spike glycoprotein. Our data suggests that 2019-nCoV is newly spilled coronavirus into humans in China is closely related to SARS-CoV, which has only 12.8% of difference with SARS-CoV in S protein and has 83.9% similarity in minimal receptor-binding domain with SARS-CoV. Addition of a novel glycosylation sites were observed in 2019-nCoV. In addition, antigenic analysis proposes that great antigenic differences exist between both the viral strains, but some of the epitopes were found to be similar between both the S proteins. In spite of the variation in S protein amino acid composition, we found no significant difference in their structures. Collectively, for the first time our results exhibit the emergence of human 2019-nCoV is closely related to predecessor SARS-CoV and provide the evidence that 2019-nCoV uses various novel glycosylation sites as SARS-CoV and may have a potential to become pandemic owing its antigenic discrepancy. Further, demonstration of novel Cytotoxic T lymphocyte epitopes may impart opportunities for the development of peptide based vaccine for the prevention of 2019-nCoV.
RESUMO
Zika virus (ZIKV) infection is a new emerging threat around the globe which might be responsible for microcephaly and Guillain-Barre syndrome in the infants. Recently, ZIKV outbreak has caused a public health crisis in Brazil after being linked to a sharp increase in birth defects. ZIKV is ssRNA virus belongs to the family Flaviviridae. It is mainly transmitted by mosquito bite specifically Aedes species and disease symptoms include fever, joint pain, muscle pain, rash, conjunctivitis, and headache. The reservoir of ZIKV is still not known. Protection at personal level by avoiding mosquito bite would help to reduce the incidence of the disease. Control of ZIKV infection by vaccination or antiviral drug either from modern, complementary and alternative medicines may be considered to be one of the most effective strategies in the long run. Large scale immunization of susceptible human population is highly required to prevent this deadly disease. Attempts should be made as soon as possible to develop effective vaccines or antiviral to prevent ZIKV infection. This article provides a current overview of the experimental therapeutics and treatment options based on modern, complementary and alternative medicines.
RESUMO
Infectious diseases remain a leading source of human morbidity and mortality. Recently, emerging infectious diseases are dominated by zoonoses, and eventually rising considerably. Their emergence is dependent on various factors especially, socioeconomic, environmental and ecological factors etc. Recently, the swift spread of Zika virus (ZIKV) through the Americas, simultaneously with the association of infection with microcephaly and Guillain-Barré syndrome, has strained this previously overlooked virus into the global attention. ZIKV is an emerging mosquito-borne Flavivirus, identified in rhesus monkey in 1947 in Uganda, and eventually in human in 1952. Considering the severity and recent spread over Americas, it has been declared as a public health emergency of international concern, and expected number of cases may be around three to four million. Therefore, it's important for all to assess the risk and be prepared in all possible ways before it makes a huge loss and spread globally. This news tries to discuss the possible reasons for its spread, risk assessment, and options to obliterate ZIKV.
