Displaying publications 41 - 60 of 161 in total

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  1. Fulltext Synthesis and anti-HIV activity of novel 3-substituted phenyl-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues
    Ali MA, Ismail R, Choon TS, Yoon YK, Wei AC, Pandian S, et al.
    Acta Pol Pharm, 2011 May-Jun;68(3):343-8.
    PMID: 21648188
    A series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized by the reaction of 5,6-dimethoxy-2-[(E)-1-phenylmethylidene]-1-indanone with hydroxylamine hydrochloride. The title compounds were tested for their in vitro anti-HIV activity. Among the compounds, (4g) showed a promising anti-HIV activity in the in vitro testing against IIIB and ROD strains. The IC50 of both IIIB and ROD were found to be 9.05 microM and > 125 microM, respectively.
    Matched MeSH terms: Virus Replication/drug effects
  2. Synthesis of novel 6-azapyrimidine acyclic nucleoside analogues and antiviral evaluation
    Jasamai M, Simons C, Balzarini J
    Nucleosides Nucleotides Nucleic Acids, 2010 Jul;29(7):535-41.
    PMID: 20589572 DOI: 10.1080/15257771003781634
    Acyclic nucleosides have been of considerable interest since the approval of aciclovir by the FDA to be used as an antiviral agent in the 1990s. The acyclic moieties and the bases used in the experiment were either available commercially or synthesized using literature methods. Vorbruggen coupling method was utilized involving reaction of persilylated heterocyclic bases with the appropriate acyclic moiety in the presence of a Lewis acid catalyst. A series of novel 6-azapyrimidine acyclic oxosugar nucleosides was successfully synthesized with a promising yield (more than 50%). An efficient method of protection and deprotection was also investigated.
    Matched MeSH terms: Virus Replication/drug effects
  3. Toona sinensis Roem tender leaf extract inhibits SARS coronavirus replication
    Chen CJ, Michaelis M, Hsu HK, Tsai CC, Yang KD, Wu YC, et al.
    J Ethnopharmacol, 2008 Oct 30;120(1):108-11.
    PMID: 18762235 DOI: 10.1016/j.jep.2008.07.048
    Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by the SARS coronavirus (SARS-CoV). The development of new antiviral agents for SARS-CoV is an important issue. We tried to find potential resource from Traditional Chinese medicine (TCM) for development of new drugs against SARS-CoV.
    Matched MeSH terms: Virus Replication/drug effects*
  4. Quantitative estimation of Nipah virus replication kinetics in vitro
    Chang LY, Ali AR, Hassan SS, AbuBakar S
    Virol J, 2006;3:47.
    PMID: 16784519
    Nipah virus is a zoonotic virus isolated from an outbreak in Malaysia in 1998. The virus causes infections in humans, pigs, and several other domestic animals. It has also been isolated from fruit bats. The pathogenesis of Nipah virus infection is still not well described. In the present study, Nipah virus replication kinetics were estimated from infection of African green monkey kidney cells (Vero) using the one-step SYBR Green I-based quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) assay.
    Matched MeSH terms: Virus Replication*
  5. Fulltext Antiviral activity of baicalein and quercetin against the Japanese encephalitis virus
    Johari J, Kianmehr A, Mustafa MR, Abubakar S, Zandi K
    Int J Mol Sci, 2012;13(12):16785-95.
    PMID: 23222683 DOI: 10.3390/ijms131216785
    Japanese encephalitis (JE), a mosquito-borne viral disease, is endemic to the entire east and southeast Asia, and some other parts of the world. Currently, there is no effective therapeutic available for JE; therefore, finding the effective antiviral agent against JEV replication is crucial. In the present study, the in vitro antiviral activity of baicalein and quercetin, two purportedly antiviral bioflavonoids, was evaluated against Japanese encephalitis virus (JEV) replication in Vero cells. Anti-JEV activities of these compounds were examined on different stages of JEV replication cycle. The effects of the compounds on virus replication were determined by foci forming unit reduction assay (FFURA) and quantitative RT-PCR. Baicalein showed potent antiviral activity with IC(50) = 14.28 µg/mL when it was introduced to the Vero cells after adsorption of JEV. Quercetin exhibited weak anti-JEV effects with IC(50) = 212.1 µg/mL when the JEV infected cells were treated with the compound after virus adsorption. However, baicalein exhibited significant effect against JEV adsorption with IC(50) = 7.27 µg/mL while quercetin did not show any anti-adsorption activity. Baicalein also exhibited direct extracellular virucidal activity on JEV with IC(50) = 3.44 µg/mL. However, results of quantitative RT-PCR experiments confirmed the findings from FFURA. This study demonstrated that baicalein should be considered as an appropriate candidate for further investigations, such as the study of molecular and cellular mechanism(s) of action and in vivo evaluation for the development of an effective antiviral compound against Japanese encephalitis virus.
    Matched MeSH terms: Virus Replication/drug effects*
  6. In vitro isolation and molecular identification of reptarenavirus in Malaysia
    Abba Y, Hassim H, Hamzah H, Ibrahim OE, Ilyasu Y, Bande F, et al.
    Virus Genes, 2016 Oct;52(5):640-50.
    PMID: 27142080 DOI: 10.1007/s11262-016-1345-7
    Boid inclusion body disease (BIBD) is a viral disease of boids caused by reptarenavirus. In this study, tissue from naturally infected boid snakes were homogenized and propagated in African Monkey kidney (Vero) and rat embryonic fibroblast (REF) cells. Virus replication was determined by the presence of cytopathic effect, while viral morphology was observed using transmission electron microscopy. Viral RNA was amplified using RT-PCR with primers specific for the L-segment of reptarenavirus; similarly, quantification of viral replication was done using qPCR at 24-144 h postinfection. Viral cytopathology was characterized by cell rounding and detachment in both Vero and REF cells. The viral morphology showed round-to-pleomorphic particles ranging from 105 to 150 nm which had sand-like granules. Sanger sequencing identified four closely associated reptarenavirus species from 15 (37.5 %) of the total samples tested, and these were named as follows: reptarenavirus UPM-MY 01, 02, 03, and 04. These isolates were phylogenetically closely related to the University Helsinki virus (UHV), Boa Arenavirus NL (ROUTV; BAV), and unidentified reptarenavirus L20 (URAV-L20). Comparison of deduced amino acid sequences further confirmed identities to L-protein of UHV, L-polymerase of BAV and RNA-dependent RNA polymerase of URAV-L20. Viral replication in Vero cells increased steadily from 24 to 72 h and peaked at 144 h. This is the first study in South East Asia to isolate and characterize reptarenavirus in boid snakes with BIBD.
    Matched MeSH terms: Virus Replication/genetics
  7. Fulltext Antiviral and virucidal activities of Duabanga grandiflora leaf extract against Pseudorabies virus in vitro
    Malik FZ, Allaudin ZN, Loh HS, Nee TK, Hani H, Abdullah R
    BMC Complement Altern Med, 2016 May 23;16:139.
    PMID: 27216794 DOI: 10.1186/s12906-016-1120-2
    Duabanga grandiflora or known in Malaysia as Berembang Bukit, Megawasih, or Pedada Bukit, is a native plant of the Southeast Asian countries. In this study, the anti-viral properties of D. grandiflora were investigated.
    Matched MeSH terms: Virus Replication/drug effects
  8. Anti-dengue virus serotype 2 activity and mode of action of a novel peptide
    Chew MF, Tham HW, Rajik M, Sharifah SH
    J Appl Microbiol, 2015 Oct;119(4):1170-80.
    PMID: 26248692 DOI: 10.1111/jam.12921
    To identify a novel antiviral peptide against dengue virus serotype 2 (DENV-2) by screening a phage display peptide library and to evaluate its in vitro antiviral activity and mode of action.
    Matched MeSH terms: Virus Replication/drug effects
  9. In vitro homotypic and heterotypic interference by defective interfering particles of West Nile virus
    Debnath NC, Tiernery R, Sil BK, Wills MR, Barrett AD
    J Gen Virol, 1991 Nov;72 ( Pt 11):2705-11.
    PMID: 1940867
    Defective interfering (DI) particles of the flavivirus West Nile (WN) were generated after as few as two high multiplicity serial passages in Vero and LLC-MK2 cells. Six cell lines (Vero, LLC-MK2, L929, HeLa, BHK-21 and SW13) were used to assay interference by DI particles in a yield reduction assay. Interference was found to vary depending on the cell type used. The highest levels of interference were obtained in LLC-MK2 cells, whereas no detectable effect was observed in BHK-21 and SW13 cells. The ability of DI virus to be propagated varied depending on the cell line used; no detectable propagation of DI virus was observed in SW13 cells. Optimum interference was obtained following co-infection of cells with DI virus and standard virus at a multiplicity of 5. Interference between DI and standard viruses occurred only when they were co-infected or when cells were infected with DI virus 1 h before standard virus. Investigation of heterotypic interference by DI particles of WN virus strains from Sarawak, India and Egypt revealed that interference was dependent on the strain of WN virus or flavivirus used as standard virus. A measure of the similarity between five strains of WN virus and other flaviviruses was made on the basis of interference by DI viruses, and was found to be similar to that based on haemagglutination inhibition tests using a panel of monoclonal antibodies.
    Matched MeSH terms: Virus Replication/genetics
  10. Characterization of significant molecular determinants of virulence of Enterovirus 71 sub-genotype B4 in Rhabdomyosarcoma cells
    Yee PTI, Mohamed RAH, Ong SK, Tan KO, Poh CL
    Virus Res, 2017 06 15;238:243-252.
    PMID: 28705680 DOI: 10.1016/j.virusres.2017.07.010
    One of the leading causes of the hand, foot and mouth disease (HFMD) is Enterovirus 71 (EV-A71), displaying symptoms such as fever and ulcers in children but some strains can produce cardiopulmonary oedema which leads to death. There is no FDA-approved vaccine for prevention of severe HFMD. The molecular determinants of virulence for EV-A71 are unclear. It could be a single or a combination of amino acids that determines virulence in different EV-A71 genotype/sub-genotypes. Several EV-A71 strains bearing single nucleotide (nt) mutations were constructed and the contribution of each mutation to virulence was evaluated. The nt(s) that contributed to significant reduction in virulence in vitro were selected and each mutation was introduced separately into the genome to construct the multiply mutated EV-A71 strain (MMS) which carried six substitutions of nt(s) at the 5'-NTR (U700C), VP1-145 (E to G), VP1-98E, VP1-244K and G64R in the vaccine seed strain that had a partial deletion within the 5'-NTR region (nt. 475-485) of Δ11bp. In comparison to the wild type strain, the MMS showed low virulence as it produced very low RNA copy number, plaque count, VP1 and had 105-fold higher TCID50, indicative of a promising LAV candidate that should be further evaluated in vivo.
    Matched MeSH terms: Virus Replication*
  11. Construction of an infectious molecular clone of Japanese encephalitis virus genotype V and its derivative subgenomic replicon capable of expressing a foreign gene
    Ishikawa T, Abe M, Masuda M
    Virus Res, 2015 Jan 2;195:153-61.
    PMID: 25451067 DOI: 10.1016/j.virusres.2014.10.010
    Japanese encephalitis virus (JEV) genotype V was originally isolated in Malaysia in 1952 and has long been restricted to the area. In 2009, sudden emergence of the genotype V in China and Korea was reported, suggesting expansion of its geographical distribution. Although studies on the genotype V are becoming more important, they have been limited partly due to lack of its infectious molecular clone. In this study, a plasmid carrying cDNA corresponding to the entire genome of JEV Muar strain, which belongs to genotype V, in the downstream of T7 promoter was constructed. Electroporation of viral RNA transcribed by T7 RNA polymerase (T7RNAP) in vitro from the plasmid led to production of progeny viruses both in mammalian and mosquito cells. Also, transfection of the infectious clone plasmid into mammalian cells expressing T7RNAP transiently or stably was demonstrated to generate infectious progenies. When the viral structural protein genes were partially deleted from the full-length cDNA, the subgenomic RNA transcribed in vitro from the modified plasmid was shown to replicate itself in mammalian cells as a replicon. The replicon carrying the firefly luciferase gene in place of the deleted structural protein genes was also shown to efficiently replicate itself and express luciferase in mammalian cells. Compared with the replicon derived from JEV genotype III (Nakayama strain), the genotype V-derived replicon appeared to be more tolerant to introduction of a foreign gene. The infectious clone and the replicons constructed in this study may serve as useful tools for characterizing JEV genotype V.
    Matched MeSH terms: Virus Replication*
  12. Fulltext Inhibition of enterovirus 71 infection by antisense octaguanidinium dendrimer-conjugated morpholino oligomers
    Tan CW, Chan YF, Quah YW, Poh CL
    Antiviral Res, 2014 Jul;107:35-41.
    PMID: 24769243 DOI: 10.1016/j.antiviral.2014.04.004
    Enterovirus 71 (EV-71) infections are generally manifested as mild hand, foot and mouth disease, but have been reported to cause severe neurological complications with high mortality rates. Treatment options remain limited due to the lack of antivirals. Octaguanidinium-conjugated morpholino oligomers (vivo-MOs) are single-stranded DNA-like antisense agents that can readily penetrate cells and reduce gene expression by steric blocking of complementary RNA sequences. In this study, inhibitory effects of three vivo-MOs that are complementary to the EV-71 internal ribosome entry site (IRES) and the RNA-dependent RNA polymerase (RdRP) were tested in RD cells. Vivo-MO-1 and vivo-MO-2 targeting the EV-71 IRES showed significant viral plaque reductions of 2.5 and 3.5 log10PFU/ml, respectively. Both vivo-MOs reduced viral RNA copies and viral capsid expression in RD cells in a dose-dependent manner. In contrast, vivo-MO-3 targeting the EV-71 RdRP exhibited less antiviral activity. Both vivo-MO-1 and 2 remained active when administered either 4h before or within 6h after EV-71 infection. Vivo-MO-2 exhibited antiviral activities against poliovirus (PV) and coxsackievirus A16 but vivo-MO-1 showed no antiviral activities against PV. Both the IRES-targeting vivo-MO-1 and vivo-MO-2 inhibit EV-71 RNA translation. Resistant mutants arose after serial passages in the presence of vivo-MO-1, but none were isolated against vivo-MO-2. A single T to C substitution at nucleotide position 533 was sufficient to confer resistance to vivo-MO-1. Our findings suggest that IRES-targeting vivo-MOs are good antiviral candidates for treating early EV-71 infection, and vivo-MO-2 is a more favorable candidate with broader antiviral spectrum against enteroviruses and are refractory to antiviral resistance.
    Matched MeSH terms: Virus Replication/drug effects*
  13. Fulltext Cordycepin Inhibits Virus Replication in Dengue Virus-Infected Vero Cells
    Panya A, Songprakhon P, Panwong S, Jantakee K, Kaewkod T, Tragoolpua Y, et al.
    Molecules, 2021 May 23;26(11).
    PMID: 34071102 DOI: 10.3390/molecules26113118
    Dengue virus (DENV) infection causes mild to severe illness in humans that can lead to fatality in severe cases. Currently, no specific drug is available for the treatment of DENV infection. Thus, the development of an anti-DENV drug is urgently required. Cordycepin (3'-deoxyadenosine), which is a major bioactive compound in Cordyceps (ascomycete) fungus that has been used for centuries in Chinese traditional medicine, was reported to exhibit antiviral activity. However, the anti-DENV activity of cordycepin is unknown. We hypothesized that cordycepin exerts anti-DENV activity and that, as an adenosine derivative, it inhibits DENV replication. To test this hypothesis, we investigated the anti-DENV activity of cordycepin in DENV-infected Vero cells. Cordycepin treatment significantly decreased DENV protein at a half-maximal effective concentration (EC50) of 26.94 μM. Moreover, DENV RNA was dramatically decreased in cordycepin-treated Vero cells, indicating its effectiveness in inhibiting viral RNA replication. Via in silico molecular docking, the binding of cordycepin to DENV non-structural protein 5 (NS5), which is an important enzyme for RNA synthesis, at both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, was predicted. The results of this study demonstrate that cordycepin is able to inhibit DENV replication, which portends its potential as an anti-dengue therapy.
    Matched MeSH terms: Virus Replication/drug effects*
  14. Fulltext A Brief Overview of Potential Treatments for Viral Diseases Using Natural Plant Compounds: The Case of SARS-Cov
    Abiri R, Abdul-Hamid H, Sytar O, Abiri R, Bezerra de Almeida E, Sharma SK, et al.
    Molecules, 2021 Jun 24;26(13).
    PMID: 34202844 DOI: 10.3390/molecules26133868
    The COVID-19 pandemic, as well as the more general global increase in viral diseases, has led researchers to look to the plant kingdom as a potential source for antiviral compounds. Since ancient times, herbal medicines have been extensively applied in the treatment and prevention of various infectious diseases in different traditional systems. The purpose of this review is to highlight the potential antiviral activity of plant compounds as effective and reliable agents against viral infections, especially by viruses from the coronavirus group. Various antiviral mechanisms shown by crude plant extracts and plant-derived bioactive compounds are discussed. The understanding of the action mechanisms of complex plant extract and isolated plant-derived compounds will help pave the way towards the combat of this life-threatening disease. Further, molecular docking studies, in silico analyses of extracted compounds, and future prospects are included. The in vitro production of antiviral chemical compounds from plants using molecular pharming is also considered. Notably, hairy root cultures represent a promising and sustainable way to obtain a range of biologically active compounds that may be applied in the development of novel antiviral agents.
    Matched MeSH terms: Virus Replication/drug effects
  15. Fulltext AIM2 Inflammasome-Mediated Pyroptosis in Enterovirus A71-Infected Neuronal Cells Restricts Viral Replication
    Yogarajah T, Ong KC, Perera D, Wong KT
    Sci Rep, 2017 07 19;7(1):5845.
    PMID: 28724943 DOI: 10.1038/s41598-017-05589-2
    Encephalomyelitis is a well-known complication of hand, foot, and mouth disease (HFMD) due to Enterovirus 71 (EV71) infection. Viral RNA/antigens could be detected in the central nervous system (CNS) neurons in fatal encephalomyelitis but the mechanisms of neuronal cell death is not clearly understood. We investigated the role of absent in melanoma 2 (AIM2) inflammasome in neuronal cell death, and its relationship to viral replication. Our transcriptomic analysis, RT-qPCR, Western blot, immunofluorescence and flow cytometry studies consistently showed AIM2 gene up-regulation and protein expression in EV-A71-infected SK-N-SH cells. Downstream AIM2-induced genes, CARD16, caspase-1 and IL-1β were also up-regulated and caspase-1 was activated to form cleaved caspase-1 p20 subunits. As evidenced by 7-AAD positivity, pyroptosis was confirmed in infected cells. Overall, these findings have a strong correlation with decreases in viral titers, copy numbers and proteins, and reduced proportions of infected cells. AIM2 and viral antigens were detected by immunohistochemistry in infected neurons in inflamed areas of the CNS in EV-A71 encephalomyelitis. In infected AIM2-knockdown cells, AIM2 and related downstream gene expressions, and pyroptosis were suppressed, resulting in significantly increased virus infection. These results support the notion that AIM2 inflammasome-mediated pyroptosis is an important mechanism of neuronal cell death and it could play an important role in limiting EV-A71 replication.
    Matched MeSH terms: Virus Replication*
  16. Antiviral activity of selected flavonoids against Chikungunya virus
    Lani R, Hassandarvish P, Shu MH, Phoon WH, Chu JJ, Higgs S, et al.
    Antiviral Res, 2016 Sep;133:50-61.
    PMID: 27460167 DOI: 10.1016/j.antiviral.2016.07.009
    This study focuses on the antiviral activity of selected flavonoids against the Chikungunya virus (CHIKV), a mosquito-transmitted virus that can cause incapacitating arthritis in infected individuals. Based on the results of screening on Vero cells, the tested compounds were evaluated further with various assays, including cytotoxicity assay, virus yield assay by quantitative reverse transcription polymerase chain reaction (qRT-PCR), virus RNA replication assay with a CHIKV replicon cell line, Western blotting, and quantitative immunofluorescence assay. Baicalein, fisetin, and quercetagetin displayed potent inhibition of CHIKV infection, with 50% inhibitory concentrations [IC50] of 1.891 μg/ml (6.997 μM), 8.444 μg/ml (29.5 μM), and 13.85 μg/ml (43.52 μM), respectively, and with minimal cytotoxicity. The time-of-addition studies and various antiviral assays demonstrated that baicalein and quercetagetin mainly inhibited CHIKV binding to the Vero cells and displayed potent activity against extracellular CHIKV particles. The qRT-PCR, immunofluorescence assay, and Western blot analyses indicated that each of these flavonoids affects CHIKV RNA production and viral protein expression. These data provide the first evidence of the intracellular anti-CHIKV activity of baicalein, fisetin, and quercetagetin.
    Matched MeSH terms: Virus Replication/drug effects
  17. Fulltext Role of microRNAs in antiviral responses to dengue infection
    Wong RR, Abd-Aziz N, Affendi S, Poh CL
    J Biomed Sci, 2020 Jan 03;27(1):4.
    PMID: 31898495 DOI: 10.1186/s12929-019-0614-x
    Dengue virus (DENV) is the etiological agent of dengue fever. Severe dengue could be fatal and there is currently no effective antiviral agent or vaccine. The only licensed vaccine, Dengvaxia, has low efficacy against serotypes 1 and 2. Cellular miRNAs are post-transcriptional regulators that could play a role in direct regulation of viral genes. Host miRNA expressions could either promote or repress viral replications. Induction of some cellular miRNAs could help the virus to evade the host immune response by suppressing the IFN-α/β signaling pathway while others could upregulate IFN-α/β production and inhibit the viral infection. Understanding miRNA expressions and functions during dengue infections would provide insights into the development of miRNA-based therapeutics which could be strategized to act either as miRNA antagonists or miRNA mimics. The known mechanisms of how miRNAs impact DENV replication are diverse. They could suppress DENV multiplication by directly binding to the viral genome, resulting in translational repression. Other miRNA actions include modulation of host factors. In addition, miRNAs that could modulate immunopathogenesis are discussed. Major hurdles lie in the development of chemical modifications and delivery systems for in vivo delivery. Nevertheless, advancement in miRNA formulations and delivery systems hold great promise for the therapeutic potential of miRNA-based therapy, as supported by Miravirsen for treatment of Hepatitis C infection which has successfully completed phase II clinical trial.
    Matched MeSH terms: Virus Replication/genetics
  18. Fulltext RSAD2 and AIM2 Modulate Coxsackievirus A16 and Enterovirus A71 Replication in Neuronal Cells in Different Ways That May Be Associated with Their 5' Nontranslated Regions
    Yogarajah T, Ong KC, Perera D, Wong KT
    J Virol, 2018 03 15;92(6).
    PMID: 29263272 DOI: 10.1128/JVI.01914-17
    Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are closely related enteroviruses that cause the same hand, foot, and mouth disease (HFMD), but neurological complications occur only very rarely in CV-A16 compared to EV-A71 infections. To elucidate host responses that may be able to explain these differences, we performed transcriptomic analysis and real-time quantitative PCR (RT-qPCR) in CV-A16-infected neuroblastoma cells (SK-N-SH), and the results showed that the radical S-adenosylmethionine domain containing 2 (RSAD2) was the highest upregulated gene in the antimicrobial pathway. Increased RSAD2 expression was correlated with reduced viral replication, while RSAD2 knockdown cells were correlated with increased replication. EV-A71 replication showed no apparent correlation to RSAD2 expressions. Absent in melanoma 2 (AIM2), which is associated with pyroptotic cell death, was upregulated in EV-A71-infected neurons but not in CV-A16 infection, suggesting that the AIM2 inflammasome played a significant role in suppressing EV-A71 replication. Chimeric viruses derived from CV-A16 and EV-A71 but containing swapped 5' nontranslated regions (5' NTRs) showed that RSAD2 expression/viral replication and AIM2 expression/viral replication patterns may be linked to the 5' NTRs of parental viruses. Differences in secondary structure of internal ribosomal entry sites within the 5' NTR may be responsible for these findings. Overall, our results suggest that CV-A16 and EV-A71 elicit different host responses to infection, which may help explain the apparent lower incidence of CV-A16-associated neurovirulence in HFMD outbreaks compared to EV-A71 infection.IMPORTANCE Although coxsackievirus A16 (CV-A16) and enterovirus A17 (EV-A71) both cause hand, foot, and mouth disease, EV-A71 has emerged as a leading cause of nonpolio, enteroviral fatal encephalomyelitis among young children. The significance of our research is in the identification of the possible differing and novel mechanisms of CV-A16 and EV-A71 inhibition in neuronal cells that may impact viral neuropathogenesis. We further showed that viral 5' NTRs may play significant roles in eliciting different host response mechanisms.
    Matched MeSH terms: Virus Replication/physiology*
  19. Immediately early 2 (IE-2) and DNA polymerase SiRNA as virus-specific antiviral against novel transplacental cytomegalovirus strain ALL-03 in vitro
    Balakrishnan KN, Abdullah AA, Bala JA, Jesse FFA, Abdullah CAC, Noordin MM, et al.
    Infect Genet Evol, 2021 06;90:104783.
    PMID: 33640483 DOI: 10.1016/j.meegid.2021.104783
    OBJECTIVE: This study investigated the suitability of siRNA targeting specific genes that cause inhibition of virus replication in vitro especially for the virus that capable of crossing placenta and we employed a novel transplacental rat cytomegalovirus that mimics infection in human.

    METHODS: Six unique siRNAs with three each targeting different regions of IE2 (ie2a, ie2b and ie2c) and DNA polymerase (dpa, dpb and dpc) were prepared and tested for antiviral activities. The efficacy as an antiviral was determined in in-vitro by measuring TCID50 virus titer, severity of virus-induced cytopathic effect (CPE), intracellular viral genome loads by droplet digital PCR, the degree of apoptosis in siRNA-treated cells and relative expression of viral mRNA in infected Rat Embryo Fibroblast (REF) cells.

    FINDINGS: Remarkably, the siRNAs: dpa, dpb and IE2b, significantly reduced virus yield (approximately >90%) compared to control group at day 18 post infection (p.i). Changes in CPE indicated that DNA polymerase siRNAs were capable of protecting cells against CMV infection at day 14 p.i with higher efficiency than GCV (at the concentration of 300 pmol). Gene expression analysis revealed a marked down regulation of the targeted DNA polymerase gene (73.9%, 96.0% and 90.7% for dpa, dpb and dpc siRNA, respectively) and IE2 gene (50.8%, 49.9% and 15.8% for ie2a, ie2b and ie2c siRNA, respectively) when measured by RT-qPCR. Intracellular viral DNA loads showed a significant reduction for all the DNA polymerase siRNAs (dpa: 96%, dpb: 98% and dpc:92) compared to control group (P 

    Matched MeSH terms: Virus Replication*
  20. Fulltext Antiviral activity of silymarin and baicalein against dengue virus
    Low ZX, OuYong BM, Hassandarvish P, Poh CL, Ramanathan B
    Sci Rep, 2021 10 27;11(1):21221.
    PMID: 34707245 DOI: 10.1038/s41598-021-98949-y
    Dengue is an arthropod-borne viral disease that has become endemic and a global threat in many countries with no effective antiviral drug available currently. This study showed that flavonoids: silymarin and baicalein could inhibit the dengue virus in vitro and were well tolerated in Vero cells with a half-maximum cytotoxic concentration (CC50) of 749.70 µg/mL and 271.03 µg/mL, respectively. Silymarin and baicalein exerted virucidal effects against DENV-3, with a selective index (SI) of 10.87 and 21.34, respectively. Baicalein showed a better inhibition of intracellular DENV-3 progeny with a SI of 7.82 compared to silymarin. Baicalein effectively blocked DENV-3 attachment (95.59%) to the Vero cells, while silymarin prevented the viral entry (72.46%) into the cells, thus reducing viral infectivity. Both flavonoids showed promising antiviral activity against all four dengue serotypes. The in silico molecular docking showed that silymarin could bind to the viral envelope (E) protein with a binding affinity of - 8.5 kcal/mol and form hydrogen bonds with the amino acids GLN120, TRP229, ASN89, and THR223 of the E protein. Overall, this study showed that silymarin and baicalein exhibited potential anti-DENV activity and could serve as promising antiviral agents for further development against dengue infection.
    Matched MeSH terms: Virus Replication/drug effects
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