Dengue Virus Type Research Articles

Generation of dengue 3 envelope domain III using tobacco mosaic virus-based vector system and its immunological response mouse model by generating anti-dengue virus antibodies.

Producing recombinant proteins in plants has become a valuable alternative to traditional microbial or mammalian systems due to its cost-effectiveness, scalability, and ability to perform post-translational modifications. This study investigates the use of the Tobacco Mosaic Virus (TMV)-based vector system for producing the Dengue virus serotype 3 (DENV-3) envelope domain III (EDIII) protein in plants.. A fragment of the gene that encodes domain III of the dengue 3 envelope protein (D3EIII, comprising 300-420 amino acids), was effectively expressed within Nicotiana tabacum plants utilizing a transient expression system based on tobacco mosaic virus (TMV). The N-terminal 5' UTR region upstream of D3EIII notably enhanced protein yield in infected tissues. The produced recombinant protein exhibited reactivity with both (anti) D3EIII polyclonal antibodies and antibodies of anti-His tag. Upon injection of EDIII in mice, it stimulated the generation of antibodies against the dengue-specific virus. The induced antibodies demonstrated neutralizing activity against dengue virus type 3. These findings indicate that the TMV expression system is effective for producing dengue virus antigens in plants, resulting in antigens with appropriate properties and strong immunogenic potential.

Predicting repurposed drugs targeting the NS3 protease of dengue virus using machine learning-based QSAR, molecular docking, and molecular dynamics simulations

ABSTRACT Dengue fever, prevalent in Southeast Asian countries, currently lacks effective pharmaceutical interventions for virus replication control. This study employs a strategy that combines machine learning (ML)-based quantitative-structure-activity relationship (QSAR), molecular docking, and molecular dynamics simulations to discover potential inhibitors of the NS3 protease of the dengue virus. We used nine molecular fingerprints from PaDEL to extract features from the NS3 protease dataset of dengue virus type 2 in the ChEMBL database. Feature selection was achieved through the low variance threshold, F-Score, and recursive feature elimination (RFE) methods. Our investigation employed three ML models – support vector machine (SVM), random forest (RF), and extreme gradient boosting (XGBoost) – for classifier development. Our SVM model, combined with SVM-RFE, had the best accuracy (0.866) and ROC_AUC (0.964) in the testing set. We identified potent inhibitors on the basis of the optimal classifier probabilities and docking binding affinities. SHAP and LIME analyses highlighted the significant molecular fingerprints (e.g. ExtFP69, ExtFP362, ExtFP576) involved in NS3 protease inhibitory activity. Molecular dynamics simulations indicated that amphotericin B exhibited the highest binding energy of −212 kJ/mol and formed a hydrogen bond with the critical residue Ser196. This approach enhances NS3 protease inhibitor identification and expedites the discovery of dengue therapeutics.

Dengue virus type 3 infection in a traveler returning from Costa Rica to Japan in 2023

The number of dengue cases has increased dramatically in recent years. In Latin America, the number of cases and deaths in 2023 was the highest ever recorded. We report on a patient who had been infected with dengue virus during his stay in Costa Rica in September 2023, and developed the disease after returning to Japan. Plasma obtained from the patient was used for diagnosis and dengue virus serotyping by real-time PCR. The nucleotide sequence of the envelope region of dengue virus was then determined by the direct sequencing method, and this sequence was used for phylogenetic analyses. The patient was found to be infected with dengue virus type 3 genotype III. The sequence from the present case was more homologous with sequences registered in Florida, USA, associated with travel to Cuba in 2022 than with sequences registered in Costa Rica 10 years ago. The Pan American Health Organization reported that only dengue virus type 1 and 2 cases were reported in Costa Rica in 2019–2021, whereas dengue virus type 3 and 4 cases started being reported in 2022. In 2023, the reported numbers of cases with dengue virus types 3 and 4 exceeded those of dengue virus types 1 and 2. In addition, regional differences in endemic strains have been observed in Costa Rica. Our findings suggest that the dengue virus type 3 that infected the patient was more likely an influx of a strain that had been circulating in Caribbean countries such as Cuba in recent years, rather than a re-emergence of an indigenous virus in Costa Rica. The serotypes of dengue virus prevalent in Costa Rica have been changing since 2022. All four serotypes were prevalent in 2023, with a particularly sharp increase in the number of cases of dengue virus types 3 and 4. Future monitoring and surveillance are essential because changes in endemic serotypes can cause antibody-dependent enhancement, which can lead to severe dengue disease presentations.

A reporter virus particle seroneutralization assay for tick-borne encephalitis virus overcomes ELISA limitations.

Tick-borne encephalitis (TBE) virus is the most prevalent tick-transmitted orthoflavivirus in Europe. Due to the nonspecific nature of its symptoms, TBE is primarily diagnosed by ELISA-based detection of specific antibodies in the patient serum. However, cross-reactivity between orthoflaviviruses complicates the diagnosis. Specificity issues may be mitigated by serum neutralization assays (SNT), although the handling of clinically relevant orthoflaviviruses requires biosafety level (BSL) 3 conditions and they have highly divergent viral kinetics and cell tropisms. In the present study, we established a reporter virus particle (RVP)-based SNT in which the infectivity is measured by luminescence and that can be performed under BSL-2 conditions. The RVP-based SNT for TBEV exhibited a highly significant correlation with the traditional virus-based SNT (R2 = 0.8637, p < 0.0001). The RVP-based assay demonstrated a sensitivity of 92.3% (95% CI: 79.7%-97.4%) and specificity of 100% (95% CI: 81.6%-100%). We also tested the cross-reactivity of serum samples in RVP-based assays against other orthoflaviviruses (yellow fever virus, dengue virus type 2, Zika virus, West Nile virus and Japanese encephalitis virus). Interestingly, all serum samples which had tested TBEV-positive by ELISA but negative by RVP-based SNT were reactive for antibodies against other orthoflaviviruses. Thus, the RVP-based seroneutralization assay provides an added value in clinical diagnostics as well as in epidemiological studies.

A prM mutation that attenuates dengue virus replication in human cells enhances midgut infection in mosquitoes.

Dengue viruses (DENVs), like all viruses, evolve to perpetuate transmission of their species in their hosts. However, how DENV genetics influences dengue disease outbreaks remains poorly understood. Here, we examined isolates of the South Pacific dengue virus type 2 (DENV-2) that emerged in the 1970s and caused major dengue outbreaks in islands in this region until it reached Tonga, where only a few mild cases were reported. Phylogenetically, the DENV-2 strain isolated in Tonga segregated into a clade different from those clades infecting populations in other South Pacific islands. We found that this epidemiological observation could be explained by a single histidine-to-arginine substitution in position 86 of the premembrane (prM) protein of the Tonga DENV-2 strain. This mutation attenuated viral protein translation in mammalian cells but not in midgut cells of the mosquito vector Aedes aegypti. In mammalian cells, the prM mutation resulted in reduced translation of the viral genome and subsequent reduced virus replication. In contrast, in mosquito midgut cells, the prM mutation conferred a selective infection advantage, possibly because of the positively charged arginine residue introduced by the mutation. These findings provide molecular insights into the year-long silent transmission of attenuated DENV-2 in Tonga during the 1970s dengue outbreak in the South Pacific.

Exploring Microorganisms Associated to Acute Febrile Illness and Severe Neurological Disorders of Unknown Origin: A Nanopore Metagenomics Approach.

Acute febrile illness (AFI) and severe neurological disorders (SNDs) often present diagnostic challenges due to their potential origins from a wide range of infectious agents. Nanopore metagenomics is emerging as a powerful tool for identifying the microorganisms potentially responsible for these undiagnosed clinical cases. In this study, we aim to shed light on the etiological agents underlying AFI and SND cases that conventional diagnostic methods have not been able to fully elucidate. Our approach involved analyzing samples from fourteen hospitalized patients using a comprehensive nanopore metagenomic approach. This process included RNA extraction and enrichment using the SMART-9N protocol, followed by nanopore sequencing. Subsequent steps involved quality control, host DNA/cDNA removal, de novo genome assembly, and taxonomic classification. Our findings in AFI cases revealed a spectrum of disease-associated microbes, including Escherichia coli, Streptococcus sp., Human Immunodeficiency Virus 1 (Subtype B), and Human Pegivirus. Similarly, SND cases revealed the presence of pathogens such as Escherichia coli, Clostridium sp., and Dengue virus type 2 (Genotype-II lineage). This study employed a metagenomic analysis method, demonstrating its efficiency and adaptability in pathogen identification. Our investigation successfully identified pathogens likely associated with AFI and SNDs, underscoring the feasibility of retrieving near-complete genomes from RNA viruses. These findings offer promising prospects for advancing our understanding and control of infectious diseases, by facilitating detailed genomic analysis which is critical for developing targeted interventions and therapeutic strategies.

Dengue virus (DV) non-cross-reactive Omicron wave COVID-19 serums enhanced DV3 infectivity in vitro.

Introduction. In India, the SARS-CoV-2 Delta wave (2020-2021) faded away with the advent of the Omicron variants (2021-present). Dengue incidences were observed to be less in Southeast Asia during the active years of the pandemic (2020-2021). However, dengue virus type 3 (DV3) cases were increasingly reported in this region (including India) concurrent with the progression of the Omicron waves since 2022.Hypothesis. What could be the reason(s) behind this unusual DV3 surge after an overall dip in dengue incidences in many parts of Southeast Asia?Aim. We, therefore, investigated the current state of cross-reactivity of prevalent (Omicron era) SARS-CoV-2 serums with different DV serotypes and evaluated the impact of such serums on DV neutralization in cell culture.Methodology. Fifty-five COVID-19 serum samples (January-September 2022) and three pre-pandemic archived serum samples from apparently healthy individuals were tested for DV or SARS-CoV-2 IgM/IgG using the lateral flow immunoassays. DV1-4 virus neutralization tests (VNTs) were done with the SARS-CoV-2 antibody (Ab)-positive serums in Huh7 cells. DV3 envelope (env) gene was PCR amplified and sequenced for three archived DV isolates, one from 2017 and two from 2021.Results. SARS-CoV-2 Ab-positive samples constituted 74.5 % of the serums. Of these, 41.5 % were DV cross-reactive and 58.5 % were not. The DV cross-reactive serums neutralized all DV serotypes (DV1-4), as per previous results and this study. The DV non-cross-reactive serums (58.5 %) also cross-neutralized DV1, 2 and 4 but increased DV3 infectivity by means of antibody-dependent enhancement of infection as evident from significantly higher DV3 titres in VNT compared to control serums. The DV3 envelope was identical among the three isolates, including isolate 1 used in VNTs. Our results suggest that DV cross-reactivity of SARS-CoV-2 serums diminished with the shift from Delta to Omicron prevalence. Such COVID-19 serums (DV non-cross-reactive) might have played a major role in causing DV3 surge during the Omicron waves.Conclusion. Patients suspected of dengue or COVID-19 should be subjected to virus/antigen tests and serological tests for both the diseases for definitive diagnosis, prognosis and disease management.

Potential of Guava (Psidium guajava L.) as an Additional Therapy for Dengue Fever

Dengue fever has been a global health problem for over five decades, especially in tropical and subtropical countries. It is caused by a viral infection that spreads from mosquito to human. Natural sources have the potency to be an alternative to dengue fever therapy, such as guava (Psidium guajava L.). Its leaves contain several compounds and have several bioactivities. This research aims to explore the potency of guava as an additional therapy for dengue fever patients. The method used a narrative literature review that searches literature in primary data such as national or international journals with the database PubMed or Scopus. The results reported that quercetin is one of the ingredients found in guava that affects dengue fever. It suppresses intracellular replication of dengue virus type 2 (DENV-2) and inhibits ATPase in DENV-4. In addition, quercetin also stimulates stem cell factors in bone marrow stromal cells to produce thrombopoietin which functions to regulate platelet production in the spinal cord. So, guava has the potential and effectiveness to be used as an alternative therapy for dengue fever.

A Metric Based on the Efficient Determination Criterion.

This paper extends the concept of metrics based on the Bayesian information criterion (BIC), to achieve strongly consistent estimation of partition Markov models (PMMs). We introduce a set of metrics drawn from the family of model selection criteria known as efficient determination criteria (EDC). This generalization extends the range of options available in BIC for penalizing the number of model parameters. We formally specify the relationship that determines how EDC works when selecting a model based on a threshold associated with the metric. Furthermore, we improve the penalty options within EDC, identifying the penalty ln(ln(n)) as a viable choice that maintains the strongly consistent estimation of a PMM. To demonstrate the utility of these new metrics, we apply them to the modeling of three DNA sequences of dengue virus type 3, endemic in Brazil in 2023.

Antiviral activity of pimecrolimus against dengue virus type 2 infection in vitro and in vivo

Dengue virus (DENV) infection is a public health concern in several countries and is associated with severe diseases, such as dengue hemorrhagic fever and dengue shock syndrome. DENVs are transmitted to humans via the bites of infected Aedes mosquitoes, and no antiviral therapeutics are currently available. In this work, we aimed to identify antiviral drugs against DENV type 2 (DENV2) infections and selected pimecrolimus as a potential antiviral drug candidate. Pimecrolimus significantly inhibited DENV2-mediated cell death and replication in vitro. We also confirmed a decrease in the number of plaques formed as well as in the envelope protein levels of DENV2. The time-of-addition and course experiments revealed that pimecrolimus inhibited DENV2 infection during the early stages of the virus replication cycle. In an experimental mouse model, orally administered pimecrolimus alleviated body weight loss and lethality caused by DENV2 infection, which we used as readouts of the drug’s antiviral potency. Furthermore, pimecrolimus significantly inhibited the DENV2 load and ameliorated focal necrosis in the liver and spleen. Taken together, our in vitro and in vivo findings suggest that pimecrolimus is a promising antiviral drug candidate for the treatment of DENV2 infection.

Three undescribed dimeric ferulates from the culture broth of Phellinus linteus and their dengue virus type-2 inhibition activity

Several members of the genus Phellinus have been used as traditional medicine for treating various diseases. They produce unique yellow pigments composed of a styrylpyrone class of compounds. Styrylpyrones exhibit various biological activities. The styryl group is derived from phenylalanine via cinnamic acid, p-coumaric acid, and caffeoyl-CoA pathways, whereas the pyrone ring is derived from acetate. In a feeding experiment using ferulic acid, a phenylpropanoid, three undescribed dimeric ferulates designated as phellidiferulates A-C were isolated from culture broth of P. linteus. Their structures were determined by spectroscopic methods. These compounds exhibited anti-viral activities against dengue virus type 2 (DENV-2) with IC50 values ranging from 0.12 to 0.18 µg/mL.

The protective effects of Zingiber zerumbet rhizome against fevers in rats.

The Zingiber zerumbet rhizomes are traditionally used to treat fever, and the in vitro inhibitory effect of ethyl acetate extract from Zingiber zerumbet rhizomes (EAEZZR) against DENV2 NS2B/NS3 (two non-structural proteins, NS2 and NS3 of dengue virus type 2) has been reported earlier. This study was carried out to establish an acute toxicity profile and evaluate the anti-fever (anti-pyretic) activities of EAEZZR in yeast-induced fever in rats. The major compound of EAEZZR, zerumbone, was isolated using chromatographic methods including column chromatography (CC) and preparative thin-layer chromatography (PTLC). Additionally, the structure of zerumbone was elucidated using nuclear magnetic resonance (NMR), liquid chromatography mass spectrometer-ion trap-time of flight (LCMS-IT-TOF), infrared (IR), and ultraviolet (UV) spectroscopy. The toxicity of EAEZZR was evaluated using Organization for Economic Cooperation and Development Test Guideline 425 (OECD tg-425) with minor modifications at concentrations EAEZZR of 2000 mg/kg, 3000 mg/kg, and 5000 mg/kg. Anti-fever effect was determined by yeast-induced fever (pyrexia) in rats. The acute toxicity study showed that EAEZZR is safe at the highest 5000 mg/kg body weight dose in Sprague Dawley rats. Rats treated with EAEZZR at doses of 125, 250, and 500 mg/kg exhibited a significant reduction in rectal temperature (TR) in the first 1 h. EAEZZR at the lower dose of 125 mg/kg showed substantial potency against yeast-induced fever for up to 2 h compared to 0 h in controls. A significant reduction of TR was observed in rats treated with standard drug aspirin in the third through fourth hours. Based on the present findings, ethyl acetate extract of Zingiber zerumbet rhizomes could be considered safe up to the dose of 5000 mg/kg, and the identification of active ingredients of Zingiber zerumbet rhizomes may allow their use in the treatment of fever with dengue virus infection.

Extensive variation and strain-specificity in dengue virus susceptibility among African Aedes aegypti populations.

African populations of the mosquito Aedes aegypti are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive populations found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear to what extent it is true for dengue virus (DENV), the most prevalent flavivirus of humans. Addressing this question is complicated by substantial genetic diversity among DENV strains, most notably in the form of four genetic types (DENV1 to DENV4), that can lead to genetically specific interactions with mosquito populations. Here, we carried out a survey of DENV susceptibility using a panel of seven field-derived Ae. aegypti colonies from across the African range of the species and a colony from Guadeloupe, French West Indies as non-African reference. We found considerable variation in the ability of African Ae. aegypti populations to acquire and replicate a panel of six DENV strains spanning the four DENV types. Although African Ae. aegypti populations were generally less susceptible than the reference non-African population from Guadeloupe, in several instances some African populations were equally or more susceptible than the Guadeloupe population. Moreover, the relative level of susceptibility between African mosquito populations depended on the DENV strain, indicating genetically specific interactions. We conclude that unlike ZIKV susceptibility, there is no clear-cut dichotomy in DENV susceptibility between African and non-African Ae. aegypti. DENV susceptibility of African Ae. aegypti populations is highly heterogeneous and largely governed by the specific pairing of mosquito population and DENV strain.

Dengue encephalopathy in an adult due to dengue virus type 1 infection

BackgroundDengue is an important public health problem, which caused by the dengue virus (DENV), a single-stranded RNA virus consisted of four serotypes. Central nervus system (CNS) impairment in dengue usually results from DENV-2 or DENV-3 infection, which lead to life-threatening outcomes. Furthermore, neurological complications due to DENV-1 was rare especially in adult patients.Case presentationA 44-year-old man without comorbidities had lethargy after hyperpyrexia and a positive DENV NS1 antigen was detected for confirming the diagnosis of dengue on day 8 of onset. Then logagnosia, decreased muscle strength, delirium and irritability were occurred even radiographic examination were normal. He was treated with low-dose hormone, sedatives and gamma goblin with a short duration of 6 days. The cerebrospinal fluid (CSF) tests were persistent normal. However, presence of DENV-1 RNA was confirmed both in CSF and serum. Furthermore, the complete sequence of the DENV isolated from the patient’s serum was performed (GenBank No.: MW261838). The cytokines as IL-6, IL-10 and sVCAM-1 were increased in critical phase of disease. Finally, the patient was discharged on day 24 of onset without any neurological sequelae.ConclusionEncephalopathy caused by a direct CNS invasion due to DENV-1 during viremia was described in an adult patient. Treatment with low-dose hormone and gamma goblin was helpful for admission.

Evaluation for Antiviral Potential of Ficus deltoidea Against Dengue Virus Type-2

Dengue is one of the most widespread arthropod-borne viral diseases that cause negative impact globally. Presently, no effective drug is available to safeguard people against dengue. Ficus deltoidea is Malaysia's famous traditional herb belonging to Moraceae family due to its pharmacological potential. F. deltoidea leaves (FDL) were extracted with n-hexane, ethyl acetate and methanol. Cell cytotoxicity study using MTT assay measuring the formazan absorbance was conducted to determine maximum non-toxic concentration on Vero cells. The antiviral activities of various concentrations of FDL extracts were assessed using virus reduction neutralisation tests against dengue virus type 2. The CC20 value of n-hexane, ethyl acetate and methanol FDL extracts were 2.99 ± 0.31, 22.15 ± 2.39, and 25.22 ± 0.42 µg/mL, respectively. Methanol FDL extract at maximum non-toxic concentration exerted strongest direct extracellular virucidal effect against DENV-2. In cell protection assay, ethyl acetate FDL extract achieved highest reduction in viral infectivity (98.17%), whereas n-hexane FDL extract showed strongest inhibition in DENV-2 viral replication in post-infection assay. Methanol FDL extract showed highest selectivity index value in direct virus inhibition, cell protection and post-infection assay. Conclusively, FDL extracts, especially methanol FDL showed potential antiviral activity against DENV-2, thus considered as promising anti-dengue agent.

Characterization of Dengue Virus 4 Cases in Paraguay, 2019-2020.

In 2019-2020, dengue virus (DENV) type 4 emerged to cause the largest DENV outbreak in Paraguay's history. This study sought to characterize dengue relative to other acute illness cases and use phylogenetic analysis to understand the outbreak's origin. Individuals with an acute illness (≤7 days) were enrolled and tested for DENV nonstructural protein 1 (NS1) and viral RNA by real-time RT-PCR. Near-complete genome sequences were obtained from 62 DENV-4 positive samples. From January 2019 to March 2020, 799 participants were enrolled: 253 dengue (14 severe dengue, 5.5%) and 546 other acute illness cases. DENV-4 was detected in 238 dengue cases (94.1%). NS1 detection by rapid test was 52.5% sensitive (53/101) and 96.5% specific (387/401) for dengue compared to rRT-PCR. DENV-4 sequences were grouped into two clades within genotype II. No clustering was observed based on dengue severity, location, or date. Sequences obtained here were most closely related to 2018 DENV-4 sequences from Paraguay, followed by a 2013 sequence from southern Brazil. DENV-4 can result in large outbreaks, including severe cases, and is poorly detected with available rapid diagnostics. Outbreak strains seem to have been circulating in Paraguay and Brazil prior to 2018, highlighting the importance of sustained DENV genomic surveillance.

Genetic regions affecting the replication and pathogenicity of dengue virus type 2.

Dengue is a mosquito-borne disease that has spread to over 100 countries. Its symptoms vary from the relatively mild acute febrile illness called dengue fever to the much more severe dengue shock syndrome. Dengue is caused by dengue virus (DENV), which belongs to the Flavivirus genus of the family Flaviviridae. There are four serotypes of DENV, i.e., DENV1 to DENV4, and each serotype is divided into distinct genotypes. Thailand is an endemic area where all four serotypes of DENV co-circulate. Genome sequencing of the DENV2 that was isolated in Thailand in 2016 and 2017 revealed the emergence of the Cosmopolitan genotype and its co-circulation with the Asian-I genotype. However, it was unclear whether different genotypes have different levels of viral replication and pathogenicity. Focus-forming assay (FFA) results showed that clinical isolates of these genotypes differed in focus size and proliferative capacity. Using circular polymerase extension reaction, we generated parental and chimeric viruses with swapped genes between these two DENV2 genotypes, and compared their focus sizes and infectivity titers using FFA. The results showed that the focus size was larger when the structural proteins and/or non-structural NS1-NS2B proteins were derived from the Cosmopolitan virus. The infectious titers were consistent with the focus sizes. Single-round infectious particle assay results confirmed that chimeric viruses with Cosmopolitan type structural proteins, particularly prM/E, had significantly increased luciferase activity. Replicon assay results showed that Cosmopolitan NS1-NS2B proteins had increased reporter gene expression levels. Furthermore, in interferon-receptor knock-out mice, viruses with Cosmopolitan structural and NS1-NS2B proteins had higher titers in the blood, and caused critical disease courses. These results suggested that differences in the sequences within the structural and NS1-NS2B proteins may be responsible for the differences in replication, pathogenicity, and infectivity between the Asian-I and Cosmopolitan viruses.

Potential inhibitors isolated from Curcuma aeruginosa against dengue virus type 2 (DENV-2) NS2B-NS3 protease activity

Dengue virus (DENV) infection remains a formidable public health concern, causing significant fatalities worldwide. The unavailability of specific anti-DENV therapeutics and poor response towards dengue vaccine have impeded efforts to prevent and control this tropical disease, thereby, there is a pressing need for effective alternative therapeutics. Curcuma species including Curcuma aeruginosa have a long history of traditional use for the prevention and treatment of various ailments, including viral infections. While it is evident that several compounds isolated from these plants have antiviral activity against various viruses, their specific effects against DENV have not been thoroughly explored. The study aimed to investigate the potential of major compounds isolated from C. aeruginosa (demethoxycurcumin, curcumenol, furanodienone germacrone and zederone) in inhibiting DENV-2 NS2B-NS3 protease activity both in vitro and in silico. The results demonstrated that demethoxycurcumin (at 100 μM), furanodienone and germacrone (both at 25 μM) exhibited inhibitory effects on NS2B-NS3 protease activity comparable to aprotinin, a potent NS2B-NS3 protease inhibitor, albeit to a lesser extent. Importantly, these inhibitory concentrations did not adversely affect the viability of normal fibroblast cell line, L-929 cells, suggesting that the compounds’ effects were specific to the protease inhibition. Further in silico molecular docking analyses indicated that demethoxycurcumin, furanodienone and germacrone displayed significant binding affinities with both DENV E protein and DENV NS2B-NS3 protease, corroborating their inhibitory activity observed in the protease inhibition assay. These promising findings collectively suggest that demethoxycurcumin, furanodienone and germacrone from C. aeruginosa merit further development as distinctive inhibitors for treating DENV infection.

Role of homoeopathy of Ayush in dengue fever

In 21st century, dengue came to the limelight. Earlier, it was taught that this is one of the eruptive fevers in human beings where in dengue, the eruption appears typically on the 6th day of the fever. Knowledge and approaches to dengue took a paradigm shift in 21st century. It came to be clubbed under the National Vector Borne Disease Control Program. A mosquito borne single stranded RNA virus is the leading cause of arthropod borne viral diseases like dengue globally. All the types of dengue virus are capable of inducing severe diseases like dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). No one wants to be in DHF or DSS stage as these are mortal stages while other stages are morbid. A vector borne disease (VBD) transmitted by mosquito has no specific cure in modern medicine. To add to that, the issue of platelet transfusion that is made universal because of the inherent panic does more harm than good. It is here that homoeopathy has a role to play therapeutically. The article discusses the disease and the related physiology as well as pathology that goes inside the body during an episode of dengue fever. Along with the diagnosis and management approaches, the article elicits the role of homoeopathy through a suggested treatment protocol. Through the inherent properties of homoeopathy such as cost effectiveness, clinical effectiveness and zero side effects, the article proposes large scale application of homoeopathy at all levels.

Inhibitory Activities of Methanolic Extracts of Carica papaya, Mentha piperita and Citrullus colocynthis Against Dengue Viruses-2 viability

This study targets the methanolic extracts from the leaves of Carica papaya (Papaya) and Mentha piperita (Mint), as well as the leaves and fruit extracts of Citrullus colocynthis (Tumma plant) for their antiviral activity against dengue virus type 2 (DENV-2) in vitro, utilizing the HepG2 cell line. The antiviral activity of the plant extracts mentioned above was assessed through a plaque formation assay on the HepG2 cell line. The methanolic extracts from the leaves of C. papaya and M. piperita demonstrated lower toxicity than the fruit extract of C. colocynthis. Notably, the fruit extract of C. colocynthis maintained the normal morphology of DENV-2- infected HepG2 cells with minimal cell mortality. The cell survival rates were found to be 80-100% for 0.30mg/ml and 0.20mg/ml of C. papaya and M. piperita leaves extracts and 0.08mg/ml of C. colocynthis fruit extract. The most effective inhibition of DENV-2 was attributed to the fruit extract of C. colocynthis, exhibiting 46.55% inhibition at 0.08mg/ml. In comparison, M. Piperita and C. papaya leaf extracts demonstrated 24.14% and 23.33% inhibition against 0.20mg/ml and 0.30mg/ml, respectively. The plaque forming unit (PFU/ml) at the highest concentration ensuring 100% cell survival was calculated as 1.5×106, 1.4×106, and 1.0×106 PFU/ml for C. papaya and M. piperita leaves extracts and C. colocynthis fruit extract, respectively. The study infers that the methanolic fruit extract of C. colocynthis exhibits a high potential for inhibiting DENV-2 compared to the other two extracts.