Spatiotemporal models of dengue epidemiology in the Philippines: Integrating remote sensing and interpretable machine learning.

Previous dengue epidemiological analyses have been limited in spatiotemporal extent or covariate dimensions, the latter neglecting the multifactorial nature of dengue. These constraints, caused by rigid and traditional statistical tools which collapse amidst 'Big Data', prompt interpretable machine-learning (iML) approaches. Predicting dengue incidence and mortality in the Philippines, a data-limited yet high-burden country, the mlr3 universe of R packages was used to build and optimize ML models based on remotely sensed provincial and dekadal 3 NDVI and 9 rainfall features from 2016 to 2020. Between two tasks, models differ across four random forest-based learners and two clustering strategies. Among 16 candidates, rfsrc-year-case and ranger-year-death significantly perform best for predicting dengue incidence and mortality, respectively. Therefore, temporal clustering yields the best models, reflective of dengue seasonality. The two best models were subjected to tripartite global exploratory model analyses, which encompass model-agnostic post-hoc methods such as Permutation Feature Importance (PFI) and Accumulated Local Effects (ALE). PFI reveals that the models differ in their important explanatory aspect, rainfall for rfsrc-year-case and NDVI for ranger-year-death, among which long-term average (lta) features are most relevant. Trend-wise, ALE reveals that average incidence predictions are positively associated with 'Rain.lta', reflective of dengue cases peaking during the wet season. In contrast, those for mortality are negatively associated with 'NDVI.lta', reflective of urban spaces driving dengue-related deaths. By technologically addressing the challenges of the human-animal-ecosystem interface, this study adheres to the One Digital Health paradigm operationalized under Sustainable Development Goals (SDGs). Leveraging data digitization and predictive modeling for epidemiological research paves SDG 3, which prioritizes holistic health and well-being.

Persistence of dengue serotype 2 viral RNA in blood cells of a returned traveler with dengue fever.

Dengue virus (DENV) is one of the most significant vector-borne pathogens worldwide. In this report, we describe clinical features and laboratory detection of dengue in a 45-year-old traveler to Nicaragua on return home to the United States in 2019. Clinical presentation was mild, with rash, headache, and fatigue, with only low-grade transient fever. Infection dynamics were documented by serology and PCR of serially collected body fluids. DENV serotype 2 was detected in whole blood 1 day after symptoms emerged, with viral RNA isolated to the red cell fraction, and remained detectable through day 89. DENV-2 RNA was detected in serum only on day 4, and IgM was undetectable on day 4 but evident by day 13. Viral RNA was also detected in urine. This report of DENV-2 RNA persistence in blood cells but only transient appearance in serum, supports the potential diagnostic value of whole blood over serum for PCR and opportunity of an expanded testing window. Informed testing approaches can improve diagnostic accuracy and inform strategies that preserve individual and public health.

Exploring the Targets of Dengue Virus and Designs of Potential Inhibitors.

BACKGROUND: Dengue, a mosquito-borne viral disease spread by the dengue virus (DENV), has become one of the most alarming health issues in the global scenario in recent days. The risk of infection by DENV is mostly high in tropical and subtropical areas of the world. The mortality rate of patients affected with DENV is ever-increasing, mainly due to a lack of anti-dengue viral-specific synthetic drug components. INTRODUCTION: Repurposing synthetic drugs has been an effective tool in combating several pathogens, including DENV. However, only the Dengvaxia vaccine has been developed so far to fight against the deadly disease despite the grave situation, mainly because of the limitations of understanding the actual pathogenicity of the disease. METHODS: To address this particular issue and explore the actual disease pathobiology, several potential targets, like three structural proteins and seven non-structural (NS) proteins, along with their inhibitors of synthetic and natural origin, have been screened using docking simulation. RESULTS: Exploration of these targets, along with their inhibitors, has been extensively studied in culmination with molecular docking-based screening to potentiate the treatment. CONCLUSION: These screened inhibitors could possibly be helpful for the designing of new congeneric potential compounds to combat dengue fever and its complications.

Dengue havoc: overview and eco-friendly strategies to forestall the current epidemic.

Dengue fever is a mosquito-borne viral illness that affects over 100 nations around the world, including Africa, America, the Eastern Mediterranean, Southeast Asia, and the Western Pacific. Those who get infected by virus for the second time are at greater risk of having persistent dengue symptoms. Dengue fever has yet to be treated with a long-lasting vaccination or medication. Because of their ease of use, mosquito repellents have become popular as a dengue prevention technique. However, this has resulted in environmental degradation and harm, as well as bioaccumulation and biomagnification of hazardous residues in the ecosystem. Synthetic pesticides have caused a plethora of serious problems that were not foreseen when they were originally introduced. The harm caused by the allopathic medications/synthetic pesticides/chemical mosquito repellents has paved the door to employment of eco-friendly/green approaches in order to reduce dengue cases while protecting the integrity of the nearby environment too. Since the cases of dengue have become rampant these days, hence, starting the medication obtained from green approaches as soon as the disease is detected is advisable. In the present paper, we recommend environmentally friendly dengue management strategies, which, when combined with a reasonable number of vector control approaches, may help to avoid the dengue havoc as well as help in maintaining the integrity of the ecosystem.

Conessine inhibits enveloped viruses replication through up-regulating cholesterol level.

Dengue virus (DENV) is one of the most prevalent arthropod-borne diseases. It may cause dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), while no effective vaccines and drugs are available. Our study demonstrated that conessine exhibits broad antiviral activity against several enveloped viruses, including DENV, vesicular stomatitis virus, and herpes simplex virus. In addition, conessine has no direct destructive effect on the integrity or infectivity of virions. Both pre-treatment and post-treatment with conessine significantly reduce DENV replication. Pre-treatment with conessine disrupts the endocytosis of enveloped viruses, while post-treatment disturbs DENV RNA replication or translation at an early stage. Through screening differentially expressed genes by transcriptome sequencing, we found that conessine may affect cholesterol biosynthesis, metabolism or homeostasis. Finally, we confirmed that conessine inhibits virus replication through up-regulating cholesterol levels. Our work suggests that conessine could be developed as a prophylactic and therapeutic treatment for infectious diseases caused by enveloped viruses.

Tracing down the Updates on Dengue Virus-Molecular Biology, Antivirals, and Vaccine Strategies.

BACKGROUND: Nearly half of the world is at risk of developing dengue infection. Dengue virus is the causative agent behind this public healthcare concern. Millions of dengue cases are reported every year, leading to thousands of deaths. The scientific community is working to develop effective therapeutic strategies in the form of vaccines and antiviral drugs against dengue. METHODS: In this review, a methodological approach has been used to gather data from the past five years to include the latest developments against the dengue virus. RESULTS: Different therapeutics and antiviral targets against the dengue virus are at different stages of development, but none have been approved by the FDA. Moreover, various vaccination strategies have also been discussed, including attenuated virus vaccines, recombinant subunit vaccines, viral vector vaccines, DNA vaccines, nanotechnology, and plant-based vaccines, which are used to develop effective vaccines for the dengue virus. Many dengue vaccines pass the initial phases of evaluation, but only two vaccines have been approved for public use. DENGVAXIA is the only FDA-approved vaccine against all four stereotypes of the dengue virus, but it is licensed for use only in individuals 6-16 years of age with laboratory-confirmed previous dengue infection and living in endemic countries. Takeda is the second vaccine approved for use in the European Union, the United Kingdom, Brazil, Argentina, Indonesia, and Thailand. It produced sustained antibody responses against all four serotypes of dengue virus, regardless of previous exposure and dosing schedule. Other dengue vaccine candidates at different stages of development are TV-003/005, TDENV PIV, V180, and some DNA vaccines. CONCLUSION: There is a need to put more effort into developing effective vaccines and therapeutics for dengue, as already approved vaccines and therapeutics have limitations. DENGVAXIA is approved for use in children and teenagers who are 6-16 years of age and have confirmed dengue infection, while Takeda is approved for use in certain countries, and it has withdrawn its application for FDA approval.

The reemergence of dengue virus in Sudan.

Dengue fever (DF) is a mosquito-transmitted arboviral disease caused by 1 of 4 closely related but antigenically distinct serotypes of dengue virus (DENV), DENV-1-4. The primary vector of DENV is Aedes aegypti and Aedes albopictus mosquitoes. Humans are the main carrier of the virus and the amplifying host with non-human primates plays a considerable role in sylvatic cycle. On November 8, 2022, an outbreak of dengue fever has killed at least five people in North Kordofan State. On 23 Nov 2022, the Sudanese Ministry of Health reported 3326 cases of dengue fever across 8 Sudanese States; while 23 patients died from the fever. Sudan is witnessing its worst outbreak of dengue fever in over a decade, especially in North and South Kordofan and Red Sea State are hit hard. In this review, we will focus on the recent outbreak of dengue fever in many Sudanese states.

Inhibition of phosphodiesterase 12 results in antiviral activity against several RNA viruses including SARS-CoV-2.

The 2',5'- oligoadenylate synthetase (OAS) - ribonuclease L (RNAseL) - phosphodiesterase 12 (PDE12) pathway is an essential interferon-induced effector mechanism against RNA virus infection. Inhibition of PDE12 leads to selective amplification of RNAseL activity in infected cells. We aimed to investigate PDE12 as a potential pan-RNA virus antiviral drug target and develop PDE12 inhibitors that elicit antiviral activity against a range of viruses. A library of 18 000 small molecules was screened for PDE12 inhibitor activity using a fluorescent probe specific for PDE12. The lead compounds (CO-17 or CO-63) were tested in cell-based antiviral assays using encephalomyocarditis virus (EMCV), hepatitis C virus (HCV), dengue virus (DENV), West Nile virus (WNV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in vitro. Cross reactivity of PDE12 inhibitors with other PDEs and in vivo toxicity were measured. In EMCV assays, CO-17 potentiated the effect of IFNα by 3 log10. The compounds were selective for PDE12 when tested against a panel of other PDEs and non-toxic at up to 42 mg kg-1 in rats in vivo. Thus, we have identified PDE12 inhibitors (CO-17 and CO-63), and established the principle that inhibitors of PDE12 have antiviral properties. Early studies suggest these PDE12 inhibitors are well tolerated at the therapeutic range, and reduce viral load in studies of DENV, HCV, WNV and SARS-CoV-2 in human cells and WNV in a mouse model.

Experimental Dengue Virus Type 4 Infection Increases the Expression of MicroRNAs-15/16, Triggering a Caspase-Induced Apoptosis Pathway.

The World Health Organization has estimated the annual occurrence of approximately 392 million dengue virus (DENV) infections in more than 100 countries where the virus is endemic, which represents a serious threat to humanity. DENV is a serologic group with four distinct serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) belonging to the genus Flavivirus, in the family Flaviviridae. Dengue is the most widespread mosquito-borne disease in the world. The ~10.7 kb DENV genome encodes three structural proteins (capsid (C), pre-membrane (prM), and envelope (E)) and seven non-structural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). The NS1 protein is a membrane-associated dimer and a secreted, lipid-associated hexamer. Dimeric NS1 is found on membranes both in cellular compartments and cell surfaces. Secreted NS1 (sNS1) is often present in patient serum at very high levels, which correlates with severe dengue symptoms. This study was conducted to discover how the NS1 protein, microRNAs-15/16 (miRNAs-15/16), and apoptosis are related during DENV-4 infection in human liver cell lines. Huh 7.5 and HepG2 cells were infected with DENV-4, and miRNAs-15/16, viral load, NS1 protein, and caspases-3/7 were quantified after different durations of infection. This study demonstrated that miRNAs-15/16 were overexpressed during the infection of HepG2 and Huh 7.5 cells with DENV-4 and had a relationship with NS1 protein expression, viral load, and the activity of caspases-3/7, thus making these miRNAs potential injury markers during DENV infection in human hepatocytes.

A short communication of 2022 dengue outbreak in Bangladesh: a continuous public health threat.

Dengue virus infection, a highly prominent health concern, has caused many health complications, positive cases, and deaths in Bangladesh in previous years. However, the prevalence of this infection and fatality rates in 2022 has shattered all prior records. The dengue virus vector, mosquitoes, found a high prevalence of infection due to the weather's favorable conditions for breeding in the months of June and July. While there is presently no particular vaccination for dengue infection, awareness of its epidemiology, pathogenesis, signs, and symptoms may aid in the development of improved diagnostic and treatment strategies. The government should also improve the infrastructure of cities to make prevent mosquito breeding and the spread of dengue infection.

Correlation of Dengue and Meteorological Factors in Bangladesh: A Public Health Concern.

Dengue virus (DENV) is an enveloped, single-stranded RNA virus, a member of the Flaviviridae family (which causes Dengue fever), and an arthropod-transmitted human viral infection. Bangladesh is well known for having some of Asia's most vulnerable Dengue outbreaks, with climate change, its location, and it's dense population serving as the main contributors. For speculation about DENV outbreak characteristics, it is crucial to determine how meteorological factors correlate with the number of cases. This study used five time series models to observe the trend and forecast Dengue cases. Current data-based research has also applied four statistical models to test the relationship between Dengue-positive cases and meteorological parameters. Datasets were used from NASA for meteorological parameters, and daily DENV cases were obtained from the Directorate General of Health Service (DGHS) open-access websites. During the study period, the mean of DENV cases was 882.26 ± 3993.18, ranging between a minimum of 0 to a maximum of 52,636 daily confirmed cases. The Spearman's rank correlation coefficient between climatic variables and Dengue incidence indicated that no substantial relationship exists between daily Dengue cases and wind speed, temperature, and surface pressure (Spearman's rho; r = -0.007, p > 0.05; r = 0.085, p > 0.05; and r = -0.086, p > 0.05, respectively). Still, a significant relationship exists between daily Dengue cases and dew point, relative humidity, and rainfall (r = 0.158, p < 0.05; r = 0.175, p < 0.05; and r = 0.138, p < 0.05, respectively). Using the ARIMAX and GA models, the relationship for Dengue cases with wind speed is -666.50 [95% CI: -1711.86 to 378.86] and -953.05 [-2403.46 to 497.36], respectively. A similar negative relation between Dengue cases and wind speed was also determined in the GLM model (IRR = 0.98). Dew point and surface pressure also represented a negative correlation in both ARIMAX and GA models, respectively, but the GLM model showed a positive association. Additionally, temperature and relative humidity showed a positive correlation with Dengue cases (105.71 and 57.39, respectively, in the ARIMAX, 633.86, and 200.03 in the GA model). In contrast, both temperature and relative humidity showed negative relation with Dengue cases in the GLM model. In the Poisson regression model, windspeed has a substantial significant negative connection with Dengue cases in all seasons. Temperature and rainfall are significantly and positively associated with Dengue cases in all seasons. The association between meteorological factors and recent outbreak data is the first study where we are aware of the use of maximum time series models in Bangladesh. Taking comprehensive measures against DENV outbreaks in the future can be possible through these findings, which can help fellow researchers and policymakers.

Replication in the presence of dengue convalescent serum impacts Zika virus neutralization sensitivity and fitness.

Introduction: Flaviviruses like dengue virus (DENV) and Zika virus (ZIKV) are mosquito-borne viruses that cause febrile, hemorrhagic, and neurological diseases in humans, resulting in 400 million infections annually. Due to their co-circulation in many parts of the world, flaviviruses must replicate in the presence of pre-existing adaptive immune responses targeted at serologically closely related pathogens, which can provide protection or enhance disease. However, the impact of pre-existing cross-reactive immunity as a driver of flavivirus evolution, and subsequently the implications on the emergence of immune escape variants, is poorly understood. Therefore, we investigated how replication in the presence of convalescent dengue serum drives ZIKV evolution. Methods: We used an in vitro directed evolution system, passaging ZIKV in the presence of serum from humans previously infected with DENV (anti-DENV) or serum from DENV-naïve patients (control serum). Following five passages in the presence of serum, we performed next-generation sequencing to identify mutations that arose during passaging. We studied two non-synonymous mutations found in the anti-DENV passaged population (E-V355I and NS1-T139A) by generating individual ZIKV mutants and assessing fitness in mammalian cells and live mosquitoes, as well as their sensitivity to antibody neutralization. Results and discussion: Both viruses had increased fitness in Vero cells with and without the addition of anti-DENV serum and in human lung epithelial and monocyte cells. In Aedes aegypti mosquitoes-using blood meals with and without anti-DENV serum-the mutant viruses had significantly reduced fitness compared to wild-type ZIKV. These results align with the trade-off hypothesis of constrained mosquito-borne virus evolution. Notably, only the NS1-T139A mutation escaped neutralization, while E-V335I demonstrated enhanced neutralization sensitivity to neutralization by anti-DENV serum, indicating that neutralization escape is not necessary for viruses passaged under cross-reactive immune pressures. Future studies are needed to assess cross-reactive immune selection in humans and relevant animal models or with different flaviviruses.

Identification and validation of ferroptosis-related genes in patients infected with dengue virus: implication in the pathogenesis of DENV.

Ferroptosis, an iron-dependent form of regulated cell death, has been associated with many virus infections. However, the role of ferroptosis in dengue virus (DENV) infection remains to be clarified. In our study, a dengue fever microarray dataset (GSE51808) of whole blood samples was downloaded from the Gene Expression Omnibus (GEO), and a list of ferroptosis related genes (FRGs) was extracted from the FerrDb. We identified 37 ferroptosis-related differentially expressed genes (FR-DEGs) in DENV-infected patient blood samples compared to healthy individuals. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses as well as protein-protein interaction (PPI) network of FR-DEGs revealed that these 37 FR-DEGs were mainly related to the C-type lectin receptor and p53 signaling pathway. Nine out of the 37 FR-DEGs (HSPA5, CAV1, HRAS, PTGS2, JUN, IL6, ATF3, XBP1, and CDKN2A) were hub genes, of which 5 were validated by qRT-PCR in DENV-infected HepG2 cells. Finally, using miRNA-mRNA regulatory network, we identified has-miR-124-3p and has-miR-16-5p as the most critical miRNAs in regulating the expression of these hub genes. In conclusion, our findings demonstrated that 5 FR-DEGs, JUN, IL6, ATF3, XBP1, and CDKN2A, and two miRNAs, has-miR-124-3p and has-miR-16-5p may implicate an essential role of ferroptosis in DENV infection, and further studies are warranted to explore the underlying mechanisms.

Antibody-Dependent Enhancement Activity of a Plant-Made Vaccine against West Nile Virus.

West Nile virus (WNV) causes annual outbreaks globally and is the leading cause of mosquito-borne disease in Unite States. In the absence of licensed therapeutics, there is an urgent need to develop effective and safe human vaccines against WNV. One of the major safety concerns for WNV vaccine development is the risk of increasing infection by related flaviviruses in vaccinated subjects via antibody-dependent enhancement of infection (ADE). Herein, we report the development of a plant-based vaccine candidate that provides protective immunity against a lethal WNV challenge mice, while minimizes the risk of ADE for infection by Zika (ZIKV) and dengue (DENV) virus. Specifically, a plant-produced virus-like particle (VLP) that displays the WNV Envelope protein domain III (wDIII) elicited both high neutralizing antibody titers and antigen-specific cellular immune responses in mice. Passive transfer of serum from VLP-vaccinated mice protected recipient mice from a lethal challenge of WNV infection. Notably, VLP-induced antibodies did not enhance the infection of Fc gamma receptor-expressing K562 cells by ZIKV or DENV through ADE. Thus, a plant-made wDIII-displaying VLP presents a promising WNV vaccine candidate that induces protective immunity and minimizes the concern of inducing ADE-prone antibodies to predispose vaccinees to severe infection by DENV or ZIKV.

Optimization of expression conditions of dengue virus NS2B-NS3 protease in E.coli and determination of enzyme activity / 中国生物制品学杂志

@#Objective To express dengue virus(DENV)NS2B-NS3 protease in E.coli,optimize the expression conditions and determine the enzyme activity,so as to lay a foundation of screening and discovering of lead compounds targeting DENV.Methods Codon-optimized NS2B-NS3 gene was inserted into pET-28a vector to construct recombinant prokaryotic expression plasmid pET-28a-NS2B-NS3,which was transformed E.coli Rosetta(DE3)competent cells and induced by IPTG to express NS2B-NS3 protease. The optimal expression conditions of NS2B-NS3 protease in E.coli were determined by optimizing induction length,induction temperature and IPTG concentration. NS2B-NS3 protease was isolated and purified by HisTrap~(TM) affinity chromatography column and measured for the protease activity by fluorescence resonance energy transfer(FRET)assay.Results The recombinant prokaryotic expression plasmid pET-28a-NS2B-NS3 was constructed correctly as identified by restriction analysis(NheⅠ/XhoⅠ)and sequencing. The optimal expression conditions of NS2BNS3 protease in E.coli were as follows:induction temperature of 20 ℃,induction length of 10 h and IPTG concentration of0. 2 mmol/L. The purified NS2B-NS3 protease showed a purity of more than 90% with a exhibited a of 20 mg/L,which bound to mouse monoclonal antibody against His-tag specifically and had good hydrolytic activity with a specific activity of 16. 111 U/mg,a K_m of 16. 46 μmol/L and a k_(cat) of 0. 028/s.Conclusion DENV NS2B-NS3 protease with high purity and activity was successfully prepared,which laid an experimental foundation of the establishment of high-throughput screening model for inhibitors targeting NS2B-NS3 protease.

Construction of CeRNA network of differential LncRNAs in THP-1 cells infected by Dengue virus type Ⅲ and its antibody dependent enhancement / 中国生物制品学杂志

@#ObjectiveTo establish models of Dengue virus type Ⅲ（DENV-3,DV-3）infection and antibody dependent enhancement(ADE)infection at the acute monocytic leukemia cells(THP-1),investigate the differential expression of long non-coding RNAs(LncRNAs),map the competitive endogenous RNA(CeRNA)regulatory network and predict the translation function of LncRNAs.MethodsThe culture supernatant was harvested 6 d after C6/36 cells were infected with DENV-3,the virus titer was determined by CCID50,and the type and full-length genome amplification were identified by PCR;The DENV-3 standard plasmid was amplified,identified by PCR,and the standard curve was drawn;THP-1 cells were divided into negative control group(THP-1),direct infection group(DV-3),ADE group and blank control group[1640(-)]. After 48 h of infection,the total RNA was extracted and the copy number of intracellular virus nucleic acid was measured;Through the whole transcriptome sequencing technology,the CeRNA regulatory network was constructed for the top five up-regulated and down-regulated LncRNAs in THP-1 vs DENV3,THP-1 vs ADE,DENV3 vs ADE groups,and the functions of their coding proteins were analyzed.ResultsC6/36 cells infected with DENV-3 for 3 d showed obvious cell fusion,vacuoles and abscission;The virus had a titer of about 1. 0 × 104. 64PFU/mL and was identified as DENV-3 by PCR specific primers,of which the complete gene sequence was obtained;The number of viral nucleic acid copies in ADE group was significantly higher than those in DV-3 group and blank control group;In THP-1 vs DENV-3,the expression of cytohesin interacting protein(CYTIP)was predicted to be up-regulated;In THP-1 vs ADE,the expression of kinesin family5A(KIF5A)was predicted to be down-regulated;In DENV-3 vs ADE,the expression of cluster differentiation antigen 9(CD9)and insulin like growth factor 2(IGF2)was predicted to be up-regulated. All of these differential LncRNAs had open reading frames(ORFs). Except Lnc-SH3BP1 and Lnc-RPL41,all of the other LncRNAs had internal ribosome binding site(IRES).ConclusionIn DENV-3 infection of THP-1 cells and ADE infection mediated by DENV-3,the expression of LncRNAs has changed significantly,and may regulate the process of infection through a variety of biological functions,which is helpful for a deeper understanding of the mechanism of ADE infection.

Contribution of phylogenetics to understanding the evolution and epidemiology of dengue virus.

Dengue virus (DENV) is one of the most important arboviral pathogens in the tropics and subtropics, and nearly one-third of the world's population is at risk of infection. The transmission of DENV involves a sylvatic cycle between nonhuman primates (NHP) and Aedes genus mosquitoes, and an endemic cycle between human hosts and predominantly Aedes aegypti. DENV belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes (DENV-1-4). Phylogenetic analyses of DENV have revealed its origin, epidemiology, and the drivers that determine its molecular evolution in nature. This review discusses how phylogenetic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.

Novel Antiviral Efficacy of Hedyotis diffusa and Artemisia capillaris Extracts against Dengue Virus, Japanese Encephalitis Virus, and Zika Virus Infection and Immunoregulatory Cytokine Signatures.

Currently, there are no specific therapeutics for flavivirus infections, including dengue virus (DENV) and Zika virus (ZIKV). In this study, we evaluated extracts from the plants Hedyotis diffusa (HD) and Artemisia capillaris (AC) to determine the antiviral activity against DENV, ZIKV, and Japanese encephalitis virus (JEV). HD and AC demonstrated inhibitory activity against JEV, ZIKV, and DENV replication and reduced viral RNA levels in a dose-responsive manner, with non-cytotoxic concentration ranging from 0.1 to 10 mg/mL. HD and AC had low cytotoxicity to Vero cells, with CC50 values of 33.7 ± 1.6 and 30.3 ± 1.7 mg/mL (mean ± SD), respectively. The anti-flavivirus activity of HD and AC was also consistent in human cell lines, including human glioblastoma (T98G), human chronic myeloid leukemia (K562), and human embryonic kidney (HEK-293T) cells. Viral-infected, HD-treated cells demonstrated downregulation of cytokines including CCR1, CCL26, CCL15, CCL5, IL21, and IL17C. In contrast, CCR1, CCL26, and AIMP1 were elevated following AC treatment in viral-infected cells. Overall, HD and AC plant extracts demonstrated flavivirus replication inhibitory activity, and together with immunoregulatory cytokine signatures, these results suggest that HD and AC possess bioactive compounds that may further be refined as promising candidates for clinical applications.