scholarly journals Doratoxylon apetalum, an Indigenous Medicinal Plant from Mascarene Islands, Is a Potent Inhibitor of Zika and Dengue Virus Infection in Human Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2382 ◽  
Author(s):  
Juliano G. Haddad ◽  
Andrea Cristine Koishi ◽  
Arnaud Gaudry ◽  
Claudia Nunes Duarte dos Santos ◽  
Wildriss Viranaicken ◽  
...  

Zika virus (ZIKV) and Dengue virus (DENV) are mosquito-borne viruses of the Flavivirus genus that could cause congenital microcephaly and hemorrhage, respectively, in humans, and thus present a risk to global public health. A preventive vaccine against ZIKV remains unavailable, and no specific antiviral drugs against ZIKV and DENV are licensed. Medicinal plants may be a source of natural antiviral drugs which mostly target viral entry. In this study, we evaluate the antiviral activity of Doratoxylum apetalum, an indigenous medicinal plant from the Mascarene Islands, against ZIKV and DENV infection. Our data indicated that D. apetalum exhibited potent antiviral activity against a contemporary epidemic strain of ZIKV and clinical isolates of four DENV serotypes at non-cytotoxic concentrations in human cells. Time-of-drug-addition assays revealed that D. apetalum extract acts on ZIKV entry by preventing the internalisation of virus particles into the host cells. Our data suggest that D. apetalum-mediated ZIKV inhibition relates to virus particle inactivation. We suggest that D. apetalum could be a promising natural source for the development of potential antivirals against medically important flaviviruses.

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1267
Author(s):  
Aussara Panya ◽  
Nunghathai Sawasdee ◽  
Pucharee Songprakhon ◽  
Yingmanee Tragoolpua ◽  
Siriphorn Rotarayanont ◽  
...  

Dengue virus (DENV) infection has become a critically important globally prevalent infectious disease, especially in tropical and subtropical countries. Since neither currently exists, there is an urgent need for an effective vaccine to prevent, and a specific drug to treat DENV infection. Therapeutic peptides represent an attractive alternative for development into anti-DENV drugs due to their safety and their diverse biological and chemical properties. We recently reported novel bioactive peptides extracted from the Asian medicinal plant Acacia catechu that efficiently inhibited all four DENV serotypes. In this study, we investigated the anti-DENV activity of a synthetic bioactive peptide derived from this plant. The most effective peptide (designated Pep-RTYM) inhibited DENV infection with a half-maximal inhibition concentration value of 7.9 μM. Time-of-addition study demonstrated that Pep-RTYM interacted with DENV particles and inhibited cellular entry. Pep-RTYM at 50 μM significantly reduced DENV production in Vero-kidney epithelial cells about 1000-fold, but it could decrease the virus production in Huh7 hepatocyte cells approximately 40-fold. Binding of Pep-RTYM to DENV particles may prevent virus interaction with cellular receptor and subsequent virus entry. This finding suggests a potential role of Pep-RTYM in the development of a novel anti-DENV drug.


2020 ◽  
Vol 21 (21) ◽  
pp. 7816
Author(s):  
Juliano G. Haddad ◽  
Andrea Cristine Koishi ◽  
Arnaud Gaudry ◽  
Claudia Nunes Duarte dos Santos ◽  
Wildriss Viranaicken ◽  
...  

The author wishes to make the following correction to this paper [...]


Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 367
Author(s):  
Mohd Ishtiaq Anasir ◽  
Babu Ramanathan ◽  
Chit Laa Poh

Dengue virus (DENV) presents a significant threat to global public health with more than 500,000 hospitalizations and 25,000 deaths annually. Currently, there is no clinically approved antiviral drug to treat DENV infection. The envelope (E) glycoprotein of DENV is a promising target for drug discovery as the E protein is important for viral attachment and fusion. Understanding the structure and function of DENV E protein has led to the exploration of structure-based drug discovery of antiviral compounds and peptides against DENV infections. This review summarizes the structural information of the DENV E protein with regards to DENV attachment and fusion. The information enables the development of antiviral agents through structure-based approaches. In addition, this review compares the potency of antivirals targeting the E protein with the antivirals targeting DENV multifunctional enzymes, repurposed drugs and clinically approved antiviral drugs. None of the current DENV antiviral candidates possess potency similar to the approved antiviral drugs which indicates that more efforts and resources must be invested before an effective DENV drug materializes.


2021 ◽  
Author(s):  
Mirza Sarwar Baig ◽  
Anuja Krishnan

Abstract Hyperendemic circulation of all four Dengue virus (DENV) serotypes is a severe global public health problem, so any vaccine or therapeutics should be able to target all four of them. Cells of hemopoietic origin are believed to be primary sites of DENV replication. This study aimed to identify potential host miRNAs that target 3' UTR of all 4 DENV serotypes, thereby directly regulating viral gene expression or indirectly modulating the host system at different virus infection steps. We used four prediction algorithms viz. miRanda, RNA22, RNAhybrid, and StarMir for predicting miRNA, targeting 3'UTR of all four DENV serotypes. Statistically, the most significant miRNA targets were screened based on their Log10 P-value (> 0.0001) of GO term and KEGG pathway enrichment analysis. The intersection test of at least three prediction tools identified a total of 30 miRNAs, which could bind to 3'UTR of all four DENV serotypes. Of the 30, eight miRNAs were of hematopoietic cell origin. GO term enrichment and KEGG analysis showed four hemopoietic origin miRNAs target genes of the biological processes mainly involved in the innate immune response, mRNA 3'-end processing, antigen processing, and presentation and nuclear-transcribed mRNA catabolic process.


2021 ◽  
Vol 118 (14) ◽  
pp. e2013941118
Author(s):  
Laura W. Alexander ◽  
Rotem Ben-Shachar ◽  
Leah C. Katzelnick ◽  
Guillermina Kuan ◽  
Angel Balmaseda ◽  
...  

Dengue is the most prevalent arboviral disease worldwide, and the four dengue virus (DENV) serotypes circulate endemically in many tropical and subtropical regions. Numerous studies have shown that the majority of DENV infections are inapparent, and that the ratio of inapparent to symptomatic infections (I/S) fluctuates substantially year-to-year. For example, in the ongoing Pediatric Dengue Cohort Study (PDCS) in Nicaragua, which was established in 2004, the I/S ratio has varied from 16.5:1 in 2006–2007 to 1.2:1 in 2009–2010. However, the mechanisms explaining these large fluctuations are not well understood. We hypothesized that in dengue-endemic areas, frequent boosting (i.e., exposures to DENV that do not lead to extensive viremia and result in a less than fourfold rise in antibody titers) of the immune response can be protective against symptomatic disease, and this can explain fluctuating I/S ratios. We formulate mechanistic epidemiologic models to examine the epidemiologic effects of protective homologous and heterologous boosting of the antibody response in preventing subsequent symptomatic DENV infection. We show that models that include frequent boosts that protect against symptomatic disease can recover the fluctuations in the I/S ratio that we observe, whereas a classic model without boosting cannot. Furthermore, we show that a boosting model can recover the inverse relationship between the number of symptomatic cases and the I/S ratio observed in the PDCS. These results highlight the importance of robust dengue control efforts, as intermediate dengue control may have the potential to decrease the protective effects of boosting.


2014 ◽  
Vol 8 (07) ◽  
pp. 876-884 ◽  
Author(s):  
Diana Carolina Quintero-Gil ◽  
Marta Ospina ◽  
Jorge Emilio Osorio-Benitez ◽  
Marlen Martinez-Gutierrez

Introduction: Different dengue virus (DENV) serotypes have been associated with greater epidemic potential. In turn, the increased frequency in cases of severe forms of dengue has been associated with the cocirculation of several serotypes. Because Colombia is a country with an endemic presence of all four DENV serotypes, the aim of this study was to evaluate the in vivo and in vitro replication of the DENV-2 and DENV-3 strains under individual infection and coinfection conditions. Methodology: C6/36HT cells were infected with the two strains individually or simultaneously (coinfection). Replication capacity was evaluated by RT-qPCR, and the effects on cell viability were assessed with an MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Additionally, Aedes aegypti mosquitoes were artificially fed the two strains of each serotype individually or simultaneously. The viral genomes were quantified by RT-qPCR and the survival of the infected mosquitoes was compared to that of uninfected controls. Results: In single infections, three strains significantly affected C6/36HT cell viability, but no significant differences were found in the replication capacities of the strains of the same serotype. In the in vivo infections, mosquito survival was not affected, and no significant differences in replication between strains of the same serotype were found. Finally, in coinfections, serotype 2 replicated with a thousandfold greater efficiency than serotype 3 did both in vitro and in vivo. Conclusions: Due to the cocirculation of serotypes in endemic regions, further studies of coinfections in a natural environment would further an understanding of the transmission dynamics that affect DENV infection epidemiology.


2014 ◽  
Vol 95 (3) ◽  
pp. 591-600 ◽  
Author(s):  
Meng Ling Moi ◽  
Tomohiko Takasaki ◽  
Tsutomu Omatsu ◽  
Shinichiro Nakamura ◽  
Yuko Katakai ◽  
...  

There are four dengue virus (DENV) serotypes. Primary infection with one does not confer protective immunity against the others. We have reported previously that the marmoset (Callithrix jacchus) is a useful primary DENV infection model. It has been reported that secondary DENV infection with a heterotypic serotype induces viraemia kinetics and antibody responses that differ from those in primary infection. Thus, it is important to determine the utility of the marmoset as a model for secondary DENV infection. Marmosets were infected with heterologous DENV by secondary inoculation, and viraemia kinetics and antibody responses were analysed. The marmosets consistently developed high levels of viraemia after the secondary inoculation with heterologous DENV serotypes. IgM responses were lower compared with primary inoculation responses, whilst IgG responses were rapid and high. Neutralizing activities, which possessed serotype cross-reactive activities, were detected as early as 4 days after inoculation. In addition, infectious viraemia titres were higher when assayed with Fcγ receptor-expressing baby hamster kidney (BHK) cells than when assayed with conventional BHK cells, suggesting the presence of infectious virus–antibody immune complexes. After secondary infection with heterotypic DENV, the marmosets demonstrated viraemia kinetics, IgM and IgG responses, and high levels of serotype cross-reactive neutralizing antibody responses, all of which were consistent with secondary DENV infection in humans. The results indicate the marmoset as a useful animal for studying secondary, as well as primary, DENV infection.


2010 ◽  
Vol 84 (16) ◽  
pp. 8332-8341 ◽  
Author(s):  
Dong Jiang ◽  
Jessica M. Weidner ◽  
Min Qing ◽  
Xiao-Ben Pan ◽  
Haitao Guo ◽  
...  

ABSTRACT Interferons (IFNs) are key mediators of the host innate antiviral immune response. To identify IFN-stimulated genes (ISGs) that instigate an antiviral state against two medically important flaviviruses, West Nile virus (WNV) and dengue virus (DENV), we tested 36 ISGs that are commonly induced by IFN-α for antiviral activity against the two viruses. We discovered that five ISGs efficiently suppressed WNV and/or DENV infection when they were individually expressed in HEK293 cells. Mechanistic analyses revealed that two structurally related cell plasma membrane proteins, IFITM2 and IFITM3, disrupted early steps (entry and/or uncoating) of the viral infection. In contrast, three IFN-induced cellular enzymes, viperin, ISG20, and double-stranded-RNA-activated protein kinase, inhibited steps in viral proteins and/or RNA biosynthesis. Our results thus imply that the antiviral activity of IFN-α is collectively mediated by a panel of ISGs that disrupt multiple steps of the DENV and WNV life cycles.


mBio ◽  
2011 ◽  
Vol 2 (6) ◽  
Author(s):  
Panisadee Avirutnan ◽  
Richard E. Hauhart ◽  
Mary A. Marovich ◽  
Peter Garred ◽  
John P. Atkinson ◽  
...  

ABSTRACTMannose-binding lectin (MBL) is a key soluble pathogen recognition protein of the innate immune system that binds specific mannose-containing glycans on the surfaces of microbial agents and initiates complement activation via the lectin pathway. Prior studies showed that MBL-dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains deficient in different complement components, we showed that inhibition of infection by insect cell- and mammalian cell-derived DENV was primarily dependent on the lectin pathway. Human MBL also bound to DENV and neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. Experiments with human serum from naïve individuals with inherent variation in the levels of MBL in blood showed a direct correlation between the concentration of MBL and neutralization of DENV; samples with high levels of MBL in blood neutralized DENV more efficiently than those with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis.IMPORTANCEDengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation, neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. Moreover, we observed a direct correlation with the concentration of MBL in human serum and neutralization of DENV infection. Our studies suggest that common genetic polymorphisms that result in disparate levels and function of MBL in humans may impact DENV infection, pathogenesis, and disease severity.


Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7809
Author(s):  
Kanaporn Poltep ◽  
Emi E. Nakayama ◽  
Tadahiro Sasaki ◽  
Takeshi Kurosu ◽  
Yoshiki Takashima ◽  
...  

Four serotypes of dengue virus (DENV), type 1 to 4 (DENV-1 to DENV-4), exhibit approximately 25–40% of the difference in the encoded amino acid residues of viral proteins. Reverse transcription of RNA extracted from specimens followed by PCR amplification is the current standard method of DENV serotype determination. However, since this method is time-consuming, rapid detection systems are desirable. We established several mouse monoclonal antibodies directed against DENV non-structural protein 1 and integrated them into rapid DENV detection systems. We successfully developed serotype-specific immunochromatography systems for all four DENV serotypes. Each system can detect 104 copies/mL in 15 min using laboratory and clinical isolates of DENV. No cross-reaction between DENV serotypes was observed in these DENV isolates. We also confirmed that there was no cross-reaction with chikungunya, Japanese encephalitis, Sindbis, and Zika viruses. Evaluation of these systems using serum from DENV-infected individuals indicated a serotype specificity of almost 100%. These assay systems could accelerate both DENV infection diagnosis and epidemiologic studies in DENV-endemic areas.


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