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Medicinal Plants Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Binish Khaliq, Naila Ali, Ahmed Akrem, M. Yasin Ashraf, Arif Malik, Arifa Tahir, M. Zia-Ul-Haq
In addition to, a flavonoid such as quercetin and saponin was isolated from the T. sinensis leaf extract and liquor ice roots, respectively [80, 81] showed strong antiviral activity against the SARS coronavirus. These compounds stop the cellular attachment and prevent the entry of virus to the human cell. More than 10,000 different compounds like drugs, natural, and synthetic are screened, and these compounds showed the effect results against the SARS coronavirus [82]. Indole alkaloids and were isolated from eucalyptus, L. japonica and Rauwolfia and from chestnut tree, respectively inhibited aescin the SARS coronavirus replication [82]. RNA dependent RNA polymerase is the major enzyme in the replication of SARS coronavirus, which synthesized the positive and negative strand of coronavirus RNA. A toxic steroid-like cardenolides were obtained from the plant and swine testicular cells inhibited the gastro entry of coronavirus [83]. These results showed that toxic cardenolide reduce the 50% RNA copies and suppress the viral replication [83].
The Viruses
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
The neuraminidase enables influenza virus to penetrate mucous secretions by virtue of its enzymatic activity. Neuraminidase also promotes the release of the virions as they bud from the cell surface. The envelope hemagglutinin serves to attach the virus to cells by binding to cell receptors. The virus then enters the cell in an endosomal vesicle. As the pH of the vesicle becomes acidic, the hemagglutinin changes conformation and allows fusion of the viral envelope with the endosomal membrane, resulting in uncoating and release of the viral nucleocapsid into the cell cytoplasm. Influenza viruses, unlike most RNA viruses, replicate in the cell nucleus rather than in the cytoplasm. The influenza virus has a negative stranded RNA, which is not translated directly by the host cell. Initiation of replication is possible because the virus encodes and packages its own RNA-dependent RNA polymerase. The viral RNA consists of eight different single-stranded segments, each coding for at least one of the major viral proteins. If two strains of influenza A virus infect the same cell, an interchange of entire genomic segments can occur (reassortment). Unlike classical genetic recombination, splicing and rejoining of the nucleic acid is not required in this process. Related influenza A viruses also infect animals of a variety of species, including pigs and many types of birds. These viral strains represent potential pools of genetic material for pathogenic human influenza strains by reassortment of genomic segments between animal and human influenza strains that infect a common host.
Viruses as Nanomaterials
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Dushyant R. Dudhagara, Megha S. Gadhvi, Anjana K. Vala
As mentioned above, plant viruses can be used as building blocks for synthesis of nanomaterials. The natural properties of CPMV make it an attractive nanoscale building block for medical and material science applications. Generally, CPMV has a 28 nm diameter and an icosahedral capsid that contains 5.9 and 3.5 kb of positive-sense genetic material, as RNA1 and RNA2, respectively. These RNAs have a single open reading frame and are expressed through the synthesis and successive processing of precursor polyproteins. A cofactor of proteinase, 24 K proteinase, helicase, and RNA-dependent RNA polymerase are mostly found in RNA-1. RNA-2 codes for cell-to-cell and long-distance movement proteins are found in plants, as well as large (L) and small (S) coat proteins. The two domains of the L-coat protein connect with the S-coat protein, which forms asymmetric units. These 60 asymmetrical units are in control of forming the CPMV capsid (Sainsbury et al. 2010). The surface of CPMV particles is exposed and produces addressable amines (lysine), carboxylates (aspartic acid and glutamic acid), and hydroxyl (tyrosine) groups of amino acids, which can be used for various applications in selectively connected elements like redox-active molecules, fluorescent dyes, metallic and semi-conducting nanoparticles, carbohydrates, DNA, proteins, and antibodies (Steinmetz et al. 2009b).
Antiinflammatory Activities of Curcumin and Spirulina: Focus on Their Role against COVID-19
Published in Journal of Dietary Supplements, 2023
Angelica Perna, Eleonora Hay, Carmine Sellitto, Emiliano Del Genio, Maria De Falco, Germano Guerra, Antonio De Luca, Paolo De Blasiis, Angela Lucariello
Computational models were also used to verify the ability of turmeric and its derivatives to target host proteins such as interleukin (IL)-1β, IL-6, tumor necrosis factor-alpha (TNF-α) and protease-activated receptor (PAR)-1, in addition to the ACE-2 receptor, to prevent viral infection and control overproduction of early clinical responses of COVID-19. Among curcumin derivatives, hydrazinocurcumin was found to have immunomodulatory and anti-cytokine therapeutic potential against coronavirus disease (Noor and Ikram 2021). By extracting online the Nsp9 replicase protein, which plays an essential role in virus replication, Kumar et al. Kumar et al. Kumar et al. (2021) showed that curcumin seems to have multiple interactions with this protein, suggesting a possible therapeutic role against coronavirus. Docking of curcumin with Nsp9 results provided a ligand binding pocket of Nsp9; out of 11 docking complexes, six showed a direct interaction of amino acids with curcumin. The hydrogen bonds formed with curcumin involved THR 113, SER 17, GLY 41, ARG 43, LYS 62 and VAL 45. A novel drug target, due to its essential role in virus replication, is represented by the RNA-dependent RNA polymerase (RdRp). Curcumin and its derivative compound diacetylcurcumin showed stability and good binding affinity at the active site of the SARS-CoV-2 RdRp-RNA complex (Singh et al., 2021), suggesting a further mechanism by which turmeric is able to counteract SARS-CoV-2 infection.
Potential mechanism underlying the effect of matrine on COVID-19 patients revealed through network pharmacological approaches and molecular docking analysis
Published in Archives of Physiology and Biochemistry, 2023
Wenpan Peng, Yong Xu, Di Han, Fanchao Feng, Zhichao Wang, Cheng Gu, Xianmei Zhou, Qi Wu
Network pharmacology is an emerging discipline based on the development of systematic biology and polypharmacology, which involves the construction of a complex integrated drug-ingredient-gene-disease network through high-throughput screening and network analysis. This method can systematically elucidate the intervention and influence of drugs on diseases, which meets the development requirements of modernisation of TCM. Molecular docking simulations analyse the geometric structure and spatial interaction between drugs and targets using software specifically developed for drug discovery. SARS-CoV-2 and SARS-CoV bind to angiotensin-converting enzyme II (ACE2) through their S protein to invade host cells (Li et al. 2005, Zhou et al. 2020). SARS-CoV-2-3CL hydrolase (Mpro) is the core component of the proteolytic enzyme precursor of SARS-CoV-2 and contributes to RNA replication and reverse transcription (Zhang et al.2020b). RNA-dependent RNA polymerase (RdRp) is a necessary enzyme for the replication of RNA viruses with the exception of retroviruses. As these three proteases are crucial for virus replication and control of host cells, they have also become important targets for the development of antiviral drugs (Park et al.2016, Riccio et al.2019).This study aimed to assess the mechanism underlying the effects of matrine on COVID-19 through network pharmacology and molecular docking simulations (Figure 1).
An overview on the use of antivirals for the treatment of patients with COVID19 disease
Published in Expert Opinion on Investigational Drugs, 2021
Maricar Malinis, Dayna McManus, Matthew Davis, Jeffrey Topal
SARS-CoV-2 is a single-stranded RNA-enveloped virus with a spike protein, similar to other coronaviruses, which facilitates viral entry into the host cell. Figure 1 illustrates the life cycle of the virus [2]. The spike protein engages with the angiotensin-converting enzyme 2 (ACE2) receptor, found in various organs such as the heart, lung, gastrointestinal tract, and kidneys. After the binding process, the fusion of the viral membrane and host cell occurs [3]. The host cell type 2 transmembrane serine protease (TMPRSS2) primes the spike protein ensuing its cleavage and conformational change that allows viral entry [4,5]. SARS-CoV-2 is internalized via endocytosis, and subsequently, its genomic material is released from the endosome into the cytoplasm. The viral RNA is translated into viral polyproteins by a viral replicase complex [6]. Subsequently, the RNA-dependent RNA polymerase synthesizes viral RNA and viral structural proteins are produced. After the viral assembly, mature virions are released by exocytosis [6,7]. Steps in this viral life cycle can be potential drug targets to inhibit viral replication. Investigational agents and repurposed drugs with their corresponding mechanisms of action were summarized in Table 1.