Tatanan A from the Acorus calamus L. root inhibited dengue virus proliferation and infections

A network pharmacological approach for the identification of potential therapeutic targets of Brahmi Nei - a complex traditional Siddha formulation

Brahmi Nei (BN), a traditional Indian polyherbal formulation has been described in classical texts for the treatment of anxiety and depression, as well as to fortify the immune system. The individual herbs of BN have been used for treatment of wide range of disorders including cognition, inflammation, skin ailments and cancer etc., This diverse basket of therapeutic activity suggests that BN may possess therapeutic benefits to other disorders. So, the present study aims to identify the potential therapeutic targets of BN using a network pharmacological approach to comprehend the multi target action of its multiple phytoconstituents. We have employed Randić Index for the first time to calculate the contribution score of module segregated targets towards diseases. Our results suggests that BN targets could also be effective in other diseases such as lysosomal storage disorders, respiratory disorders etc., apart from neurological disorders. The key targets with highest topological measures of Targets-(Pathway)-Targets network were identified as potential therapeutic targets of BN. And the top hit target PTGS2, a gene encoding for cyclooxygenase-2 was further evaluated using molecular docking, molecular dynamic simulation and in vitro studies. Our findings open up new therapeutic facets for BN that can be explored systematically in future.Communicated by Ramaswamy H. Sarma.

Tanreqing injection inhibits dengue virus encephalitis by suppressing the activation of NLRP3 inflammasome

BACKGROUND

Encephalitis caused by dengue virus (DENV) is considered a manifestation of severe dengue. Tanreqing injection (TRQ) is a well-known Chinese patented medicine, which has been used to treat brain-related disorders by inhibiting inflammation. Nevertheless, the effects of TRQ on DENV encephalitis have not been studied. The aim of this study was to evaluate the effects of TRQ on DENV encephalitis and to explore its potential mechanisms.

METHODS

The cytotoxicity of TRQ was examined by MTT assay, and the anti-DENV activities of TRQ in BHK-21 baby hamster kidney fibroblast were evaluated through CCK-8 and plaque assays. The expression levels of NO, IL1B/IL-1β, TNFα and IL6 were measured by qRT‒PCR and ELISA in the BV2 murine microglial cell line. The inhibitory effects of TRQ on NLRP3 inflammasome activation in BV2 cells were examined by Western blotting, qRT‒PCR and ELISA. The effects of TRQ on HT22 mouse hippocampal neuronal cells were examined by CCK-8 assay, morphology observation and flow cytometry. Moreover, a DENV-infected ICR suckling mouse model was developed to investigate the protective role of TRQ in vivo.

RESULTS

TRQ decreased the release of NO, IL6, TNFα and IL1B from BV2 cells and inhibited the activation of NLRP3. The presence of the NLRP3 agonist nigericin reversed the anti-inflammatory activities of TRQ. Furthermore, TRQ inhibited the death of HT22 cells by decreasing IL1B in DENV-infected BV2 cells. In addition, TRQ significantly attenuated weight loss, reduced clinical scores and extended the survival in DENV-infected ICR suckling mice. Critically, TRQ ameliorated pathological changes in ICR suckling mice brain by inhibiting microglia and NLRP3 activation and decreasing the production of inflammatory factors and the number of dead neurons.

CONCLUSION

TRQ exerts potent inhibitory effects on dengue encephalitis in vitro and in vivo by reducing DENV-2-induced microglial activation and subsequently decreasing the inflammatory response, thereby protecting neurons. These findings demonstrate the potential of TRQ in the treatment of dengue encephalitis.

Recent Advances in Natural Products with Anti-Leukemia and Anti- Lymphoma Activities

Leukemia and lymphoma are the most common blood cancers, which pose a critical threat to the health of adults and children. The total incidence and mortality rates of both are approximately 6% globally. Compared with the expensive cost of CAR T cell therapy, natural products from animals, plants and microorganisms have the characteristics of wide-range sources and costeffectiveness in the treatment of cancer. Moreover, the drug resistance that emerged in leukemia and lymphoma treatments shows an urgent need for new drugs. However, in addition to the natural products that have been marketed in the treatment of leukemia and lymphoma, there have been a large number of studies on natural products that fight blood cancer in recent years. This review summarized the recent studies on natural compounds with anti-lymphoma and anti-leukemia activities, hoping to provide novel weapons into the drug development arsenal.

Ethnic, Botanic, Phytochemistry and Pharmacology of the Acorus L. Genus: A Review

The genus Acorus, a perennial monocotyledonous-class herb and part of the Acoraceae family, is widely distributed in the temperate and subtropical zones of the Northern and Southern Hemispheres. Acorus is rich in biological activities and can be used to treat various diseases of the nervous system, cardiovascular system, and digestive system, including Alzheimer's disease, depression, epilepsy, hyperlipidemia, and indigestion. Recently, it has been widely used to improve eutrophic water and control heavy-metal-polluted water. Thus far, only three species of Acorus have been reported in terms of chemical components and pharmacological activities. Previously published reviews have not further distinguished or comprehensively expounded the chemical components and pharmacological activities of Acorus plants. By carrying out a literature search, we collected documents closely related to Acorus published from 1956 to 2022. We then performed a comprehensive and systematic review of the genus Acorus from different perspectives, including botanical aspects, ethnic applications, phytochemistry aspects, and pharmacological aspects. Our aim was to provide a basis for further research and the development of new concepts.

Antiviral Activity of an Indole-Type Compound Derived from Natural Products, Identified by Virtual Screening by Interaction on Dengue Virus NS5 Protein

Dengue is an acute febrile illness caused by the Dengue virus (DENV), with a high number of cases worldwide. There is no available treatment that directly affects the virus or the viral cycle. The objective of this study was to identify a compound derived from natural products that interacts with the NS5 protein of the dengue virus through virtual screening and evaluate its in vitro antiviral effect on DENV-2. Molecular docking was performed on NS5 using AutoDock Vina software, and compounds with physicochemical and pharmacological properties of interest were selected. The preliminary antiviral effect was evaluated by the expression of the NS1 protein. The effect on viral genome replication and/or translation was determined by NS5 production using DENV-2 Huh-7 replicon through ELISA and viral RNA quantification using RT-qPCR. The in silico strategy proved effective in finding a compound (M78) with an indole-like structure and with an effect on the replication cycle of DENV-2. Treatment at 50 µM reduced the expression of the NS5 protein by 70% and decreased viral RNA by 1.7 times. M78 is involved in the replication and/or translation of the viral genome.

Potential medicinal plants to combat viral infections: A way forward to environmental biotechnology

The viral diseases encouraged scientific community to evaluate the natural antiviral bioactive components rather than protease inhibitors, harmful organic molecules or nucleic acid analogues. For this purpose, medicinal plants have been gaining tremendous importance in the field of attenuating the various kinds of infectious and non-infectious diseases. Most of the commonly used medicines contains the bioactive components/phytoconstituents that are generally extracted from medicinal plants. Moreover, the medicinal plants offer many advantages for the recovery applications of infectious disease especially in viral infections including HIV-1, HIV-2, Enterovirus, Japanese Encephalitis Virus, Hepatitis B virus, Herpes Virus, Respiratory syncytial virus, Chandipura virus and Influenza A/H1N1. Considering the lack of acceptable drug candidates and the growing antimicrobial resistance to existing drug molecules for many emerging viral diseases, medicinal plants may offer best platform to develop sustainable/efficient/economic alternatives against viral infections. In this regard, for exploring and analyzing large volume of scientific data, bibliometric analysis was done using VOS Viewer shedding light on the emerging areas in the field of medicinal plants and their antiviral activity. This review covers most of the plant species that have some novel bioactive compound like gnidicin, gniditrin, rutin, apigenin, quercetin, kaempferol, curcumin, tannin and oleuropin which showed high efficacy to inhibit the several disease causing virus and their mechanism of action in HIV, Covid-19, HBV and RSV were discussed. Moreover, it also delves the in-depth mechanism of medicinal with challenges and future prospective. Therefore, this work delves the key role of environment in the biological field.

Identification of an effective fraction from Ampelopsis Radix with anti-dengue virus activities in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Dengue virus (DENV) infection is a global public health issue without effective therapeutic interventions. Chinese medicine with heat-clearing and detoxifying properties has been frequently used in the treatment of viral infection. Ampelopsis Radix (AR) is a traditional Chinese medicine for clearing heat and detoxification that has been widely used in the prevention and treatment of infectious diseases. However, no studies on the effects of AR against viral infection have been reported, thus far.

AIM OF THE STUDY

To explore the anti-DENV activities of the fraction (AR-1) obtained from AR both in vitro and in vivo.

MATERIALS AND METHODS

The chemical composition of AR-1 was identified by liquid chromatography-tandem MS (LC‒MS/MS). The antiviral activities of AR-1 were studied in baby hamster kidney fibroblast BHK-21 cells, ICR suckling mice and induction of interferon α/β (IFN-α/β) and IFN-γ R^-/- (AG129) mice.

RESULTS

Based on LC‒MS/MS analysis, 60 compounds (including flavonoids, phenols, anthraquinones, alkaloids and other types) were tentatively characterized from AR-1. AR-1 inhibited the cytopathic effect, the production of progeny virus and the synthesis of viral RNA and proteins by blocking DENV-2 binding to BHK-21 cells. Moreover, AR-1 significantly attenuated weight loss, decreased clinical scores and prolonged the survival of DENV-infected ICR suckling mice. Critically, the viral load in blood, brain and kidney tissues and the pathological changes in brain were remarkably alleviated after AR-1 treatment. Further study on AG129 mice showed that AR-1 obviously improved the clinical manifestations and survival rate, reduced viremia, attenuated gastric distension and relieved the pathological lesions caused by DENV.

CONCLUSIONS

In summary, this is the first report that AR-1 exhibits anti-DENV effects both in vitro and in vivo, which suggests that AR-1 may be developed as a therapeutic candidate against DENV infection.

Acetyl-CoA Carboxylase (ACC) Inhibitor, CP640186, Effectively Inhibited Dengue Virus (DENV) Infection via Regulating ACC Phosphorylation

Dengue fever is the most common mosquito-borne viral disease and is caused by the dengue virus (DENV). There is still a lack of efficient drugs against DENV infection, so it is urgent to develop new inhibitors for future clinical use. Our previous research indicated the role of VEGFR2/AMPK in regulating cellular metabolism during DENV infection, while acetyl-CoA carboxylase (ACC) is located downstream of AMPK and plays a crucial role in mediating cellular lipid synthesis; therefore, we speculated that an ACC inhibitor could serve as an antiviral agent against DENV. Luckily, we found that CP640186, a reported noncompetitive ACC inhibitor, significantly inhibited DENV proliferation, and CP640186 clearly reduced DENV2 proliferation at an early stage with an EC₅₀ of 0.50 μM. A mechanism study indicated that CP640186 inhibited ACC activation and destroyed the cellular lipid environment for viral proliferation. In the DENV2 infection mice model, oral CP640186 administration (10 mg/kg/day) significantly improved the mice survival rate after DENV2 infection. In summary, our research suggests that lipid synthesis plays an important role during DENV2 proliferation and indicates that CP640186 is a promising drug candidate against DNEV2 in the future.

Phytochemistry and Pharmacology of Medicinal Plants Used by the Tenggerese Society in Java Island of Indonesia

The archipelagic country of Indonesia is inhabited by 300 ethnic groups, including the indigenous people of Tengger. Based on the reported list of medicinal plants used by the Tengger community, we have reviewed each of them for their phytochemical constituents and pharmacological activities. Out of a total of 41 medicinal plants used by the Tengerrese people, 33 species were studied for their phytochemical and pharmacological properties. More than 554 phytochemicals with diverse molecular structures belonging to different chemical classes including flavonoids, terpenoids, saponins and volatiles were identified from these studied 34 medicinal plants. Many of these medicinal plants and their compounds have been tested for various pharmacological activities including anti-inflammatory, antimicrobial, wound healing, headache, antimalarial and hypertension. Five popularly used medicinal plants by the healers were Garcinia mangostana, Apium graveolens, Cayratia clematidea, Drymocallis arguta and Elaeocarpus longifolius. Only A. graviolens were previously studied, with the outcomes supporting the pharmacological claims to treat hypertension. Few unexplored medicinal plants are Physalis lagascae, Piper amplum, Rosa tomentosa and Tagetes tenuifolia, and they present great potential for biodiscovery and drug lead identification.

Research progress on the antiviral activities of natural products and their derivatives: Structure–activity relationships

Viruses spread rapidly and are well-adapted to changing environmental events. They can infect the human body readily and trigger fatal diseases. A limited number of drugs are available for specific viral diseases, which can lead to non-efficacy against viral variants and drug resistance, so drugs with broad-spectrum antiviral activity are lacking. In recent years, a steady stream of new viral diseases has emerged, which has prompted development of new antiviral drugs. Natural products could be employed to develop new antiviral drugs because of their innovative structures and broad antiviral activities. This review summarizes the progress of natural products in antiviral research and their bright performance in drug resistance issues over the past 2 decades. Moreover, it fully discusses the effect of different structural types of natural products on antiviral activity in terms of structure–activity relationships. This review could provide a foundation for the development of antiviral drugs.

Recent advances in natural products as potential inhibitors of dengue virus with a special emphasis on NS2b/NS3 protease

Dengue virus (DENV) is an arbovirus widespread through tropical and subtropical areas. It is transmitted to humans through Aedes mosquitoes. Infections with DENV can lead to a series of complications, including dengue fever, dengue haemorrhagic fever, or dengue shock syndrome, which might manifest through secondary infections because of a vulnerable immune system. To date, only one tetravalent DENV vaccine is approved to be administered to children whom have been previously DENV-infected and between 9 and 16 years of age. One of the key targets in discovering DENV antiviral agents is the NS2b/NS3 protease. This protease is a crucial enzyme complex for the proteolytic and cleavage activities of the translated polyprotein during DENV life cycle. Several studies were conducted to discover potential antivirals from natural sources or synthetic compounds and peptides. In this review, we describe the recent studies from the past five years dealing with isolated natural products as potential inhibitors of DENV with a greater focus on inhibiting the NS2b/NS3 protease. This review describes recent discoveries in anti-DENV potential of isolated phytochemicals belonging to different groups including fatty acids, glucosides, terpenes and terpenoids, flavonoids, phenolics, chalcones, acetamides, and peptides. Curcumin, quercetin, and myricetin were found to act as non-competitive inhibitors for the NS2b/NS3 protease enzyme. In some studies, the molecular targets of some of these compounds are yet to be identified using in-silico and in-vitro approaches. So far, none of the isolated natural products was tested clinically for the management of DENV infections. The discussed studies demonstrate that natural products are a rich source of potential anti-DENV compounds. However, not all of these compounds were studied for their kinetic molecular mechanism and type of inhibition. In-silico studies provided an ample number of phytochemical hits to be tested experimentally as DENV protease inhibitors. In conclusion, derivatives of these natural products can be designed and synthesised, which could enhance their specificity and efficacy towards the protease. Other sources of natural products, such as fungi, bacterial toxins, marine organisms, and animals, should also be explored towards discovering more potential and effective DENV NS2b/NS3 protease inhibitors.

The in vivo and vitro degradation of sulfonamides in wetland plants reducing phytotoxicity and environmental pollution

Aquatic plants can be used for in situ remediation of water-borne pharmaceutical compounds; however, such information and that of the potential risks of metabolites released into the environment are limited. This study determined the capacity of Canna indica and Acorus calamus used in the remediation of water-borne sulfonamides (SA). The tolerance, removal, accumulation, and biotransformation of various water-borne SAs were investigated in vivo by exposing plants to SA solutions (50 µg/L and 500 µg/L). After 28 days, C. indica removed more SAs (89.3-97.8%) than A. calamus (12.8-84.6%) and non-planted systems (8.0-69.3%). The SA removal results, except from the A. calamus system with 500 µg/L SA, fit the first-order kinetics model. The estimated half-lives of all SAs were 3-40 h and 2-60 h in the C. indica and A. calamus systems, respectively. In vivo biotransformation and rhizosphere degradation were the major phyto-removal mechanisms, constituting 24.9-81.1% and 0.0-37.1% of all SAs in the C. indica and A. calamus systems, respectively. SA acetyl metabolites were detected only in plant tissues supporting evidence for plant metabolic processes without risk into the environment. SA metabolism including oxidation, methylation, and conjugation via acetylation was potentially beneficial to accumulation and tolerate stress of antibiotic. Canna indica was more suitable for cleaning SA. Our findings better clarify the potential and low risks of phytoremediation in antibiotic-contaminated waters.

In Silico Elucidation of Potent Inhibitors from Natural Products for Nonstructural Proteins of Dengue Virus

Medicinal plants have been used from the beginning of human civilization against various health complications. Dengue virus (DENV) has emerged as one of the most widespread viruses in tropical and subtropical countries. Yet no clinically approved antiviral drug is available to combat DENV infection. Consequently, the search for novel antidengue agents from medicinal plants has assumed more insistence than in previous days. This study has focused on 31 potential antidengue molecules from secondary metabolites to examine their inhibitory activity against DENV nonstructural proteins through molecular docking and pharmacokinetics studies. In this research, the wet lab experiments were tested on a computational platform. Agathisflavone and pectolinarin are the top-scored inhibitors of DENV NS2B/NS3 protease and NS5 polymerase, respectively. Epigallocatechin gallate, Pinostrobin, Panduratin A, and Pectolinarin could be potential lead compounds against NS2B/NS3 protease, while acacetin-7-O-rutinoside against NS5 polymerase. Moreover, agathisflavone (LD50= 1430 mg/kg) and pectolinarin (LD50= 5000 mg/kg) exhibited less toxicity than nelfinavir (LD50= 600 mg/kg) and balapiravir (LD50 = 824 mg/kg), and the reference drugs. Further research on clinical trials is required to analyze the therapeutic efficacy of these metabolites to develop new potential drug candidates against different serotypes of DENV.

Prospective Asian plants with corroborated antiviral potentials: Position standing in recent years

Viral diseases are extremely widespread infections caused by viruses. Amongst numerous other illnesses, viral infections have challenged human existence severely. Over the history of mankind, new viruses have emerged and presented us with new tests. The range of viral infections varies from familiar infectious diseases such as the common cold, flu, and warts to severe ailments such as AIDS, Ebola, and COVID-19. The world has been racing to find an effective cure for the newly evolving viruses. Toxic effects, non-selectivity, drug resistance, and high price are the most common complications of conventional treatment procedures. Nature is a marvelous source of phytoconstituents with incredible varieties of biological activities. By tradition, medicinal plants have been utilized for the treatment of countless infectious diseases worldwide, some of which contain a broad spectrum of activities. Modern drug discovery and development techniques offer highly efficient separation techniques, inauguration of vector-based schemes where the original infectious virus is cloned to the non-infectious one for antiviral screening targets. The objective of the review was to gather available data on 20 both cultivated and native plants of Asia giving antiviral activities and provide comprehensive information on the phytochemical analysis of the plants and potential antiviral compounds isolated from these plants.

Traditional Knowledge to Contemporary Medication in the Treatment of Infectious Disease Dengue: A Review

Dengue has become a worldwide affliction despite incessant efforts to search for a cure for this long-lived disease. Optimistic consequences for dengue vaccine are implausible as the efficiency is tied to previous dengue virus (DENV) exposure and a very high cost is required for large-scale production of vaccine. Medicinal plants are idyllic substitutes to fight DENV infection since they constitute important components of traditional medicine and show antiviral properties, although the mechanism behind the action of bioactive compounds to obstruct viral replication is less explored and yet to be discovered. This review includes the existing traditional knowledge on how DENV infects and multiplies in the host cells, conscripting different medicinal plants that obtained bioactive compounds with anti-dengue properties, and the probable mechanism on how bioactive compounds modulate the host immune system during DENV infection. Moreover, different plant species having such bioactive compounds reported for anti-DENV efficiency should be validated scientifically via different in vitro and in vivo studies.

Production, Transmission, Pathogenesis, and Control of Dengue Virus: A Literature-Based Undivided Perspective

Dengue remains one of the most serious and widespread mosquito-borne viral infections in human beings, with serious health problems or even death. About 50 to 100 million people are newly infected annually, with almost 2.5 billion people living at risk and resulting in 20,000 deaths. Dengue virus infection is especially transmitted through bites of Aedes mosquitos, hugely spread in tropical and subtropical environments, mostly found in urban and semiurban areas. Unfortunately, there is no particular therapeutic approach, but prevention, adequate consciousness, detection at earlier stage of viral infection, and appropriate medical care can lower the fatality rates. This review offers a comprehensive view of production, transmission, pathogenesis, and control measures of the dengue virus and its vectors.

Multicomponent reactions in the synthesis of antiviral compounds

BACKGROUND

Multicomponent reactions are one-pot processes for the synthesis of highly functionalized hetero-cyclic and hetero-acyclic compounds, often endowed with biological activity.

OBJECTIVE

Multicomponent reactions are considered green processes with high atom economy. In addition, they present advantages compared to the classic synthetic methods such as high efficiency and low wastes production.

METHOD

In these reactions two or more reagents are combined together in the same flask to yield a product containing almost all the atoms of the starting materials.

RESULTS

The scope of this review is to present an overview of the application of multicomponent reactions in the synthesis of compounds endowed with antiviral activity. The syntheses are classified depending on the viral target.

CONCLUSION

Multicomponent reactions can be applied to all the stages of the drug discovery and development process making them very useful in the search for new agents active against emerging (viral) pathogens.

Phytoconstituents as Lead Compounds for Anti-Dengue Drug Discovery

Dengue is an arthropod-borne viral disease common in subtropical and tropical regions. The widespread use of traditional medicines in these regions for dengue fever (DF) has encouraged researchers to explore the therapeutic effect of herbs and their phytochemicals in dengue infection. Phytochemicals such as quercetin, baicalein, luteolin, oxindole alkaloids, celastrol and geraniin have shown significant inhibition of dengue virus in vitro. Many phytoconstituents have better selectivity index supporting their safety profile for future development. However, in vivo studies supporting therapeutic potency for these active phytoconstituents are limited. There is a need for studies translating anti-dengue profile of active phytoconstituents to find successful anti-dengue compounds.

Tenovin-1 inhibited dengue virus replication through SIRT2

Dengue fever is a common arbovirus disease, which has been spread to the entire tropical world. At present, effective drugs for the treatment of dengue fever have not yet appeared, and the dengue vaccines studied in various countries have also experienced severe adverse reactions. Thus it is urgent to find new chemicals against dengue virus. Now we found Sirtuins (SIRTs) were increased during dengue virus infection and tenovin-1, a SIRT1/2 inhibitor, showed an impressive antiviral ability in vitro. In BHK-21 cells, tenovin-1 inhibited the replication of DENV2 with an EC50 at 3.41 ± 1.10 μM, also inhibited other three types of dengue viruses with EC50 at 0.97 ± 1.11 μM, 1.81 ± 1.08 μM, 3.81 ± 1.34 μM respectively. Moreover, the cytopathic effect-induced DENV2 was largely improved by tenovin-1 treatment and the release of progeny viruses was inhibited by tenovin-1 treatment. At the same time, the viral protein level and mRNA level were decreased with tenovin-1 treatment after dengue virus infection. From the drug-addition assay, the tenovin-1 played its antiviral after viral infection, which indicated tenovin-1 was not a microbicide. Apart from its antiviral effect, tenovin-1 inhibited the inflammatory response caused by DENV2, reducing the release of inflammatory factors during viral infection. The antiviral effect of tenovin-1 was abrogated with SIRT agonist or SIRT2 knockdown treatment, which indicated the effect of tenovin-1 was on-target. In conclusion, tenovin-1 was proved to be a promising compound against flavivirus infection through SIRT2, which should be pay more attention for further study.

Brivanib alaninate inhibited dengue virus proliferation through VEGFR2/AMPK pathway

Dengue virus (DENV) is the most prevalent arthropod-borne viral disease of humans and has a major impact on global public health. There is no clinically approved drugs for DENV infection. Since intracellular VEGFR2 is increased in DENV infected patients, we thus hypothesized that VEGFR2 participated DENV proliferation and its inhibitors could be served as antivirals against DENV. Actually our results showed that VEGFR2 was induced by DENV infection. Also the agonist of VEGFR2, VEGF-A, promoted DENV proliferation. Therefore, we screened the inhibitors of VEGFR2 and found that brivanib alaninate (brivanib) showed the best anti-DENV ability with the lowest cellular cytotoxicity. Mechanically, our results indicated VEGFR2 directly interacted with PTP1B to dephosphorylate AMPK to provide lipid environment for viral replication. However, this effect could be inhibited by brivanib, which significantly reversed the reduction of AMPK phosphorylation caused by DENV infection, thus improving the cellular lipid environment. Moreover, the antiviral effect of brivanib could be reversed by AMPK inhibitor, Compound C. In addition, oral administration of brivianib (20-50 mg/kg/day) clearly improved the survival rate of DENV2 infection, and this effect was abolished in accompanied with Compound C (10mg/kg/day). Collectively, our study disclosed the mechanism of VEGFR2 in DENV2 and evaluated the antiviral ability of brivanib, which deserved more attention for clinical usage in DENV infection.

Quantitative Analysis of β-Asarone Derivatives in Acorus calamus and Herbal Food Products by HPLC-MS/MS

α-Asarone and β-asarone are reported as bioactive constituents of Acorus calamus. Phase I metabolism of asarone isomers results in a multiple spectrum of genotoxic metabolites. Thus, the question arises whether structural analogues of the known phase I metabolites also naturally occur in A. calamus-based food products. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for three product classes, herbal infusions, alcoholic beverages, and food supplements. High asarone contents were detected in herbal infusions (total mean 9.13 mg/kg, n = 8) and food supplements (total mean 14.52 mg/kg, n = 6); hence, these food products can highly contribute to human exposure to genotoxic asarone derivatives. Also, the occurrence of asarone oxidation products found in food and food supplements has to be taken under consideration because data on toxicity is limited so far.

Sesquiterpenoids of diverse types from the rhizomes of Acorus calamus

Six new and fourteen known sesquiterpenoids of diverse types were isolated from the rhizomes of Acorus calamus.

[1,2,4]Triazolo[1,5-a]pyrimidine derivative (Mol-5) is a new NS5-RdRp inhibitor of DENV2 proliferation and DENV2-induced inflammation

Dengue fever is an acute infectious disease caused by dengue virus (DENV) and transmitted by Aedes mosquitoes. There is no effective vaccine or antiviral drug available to date to prevent or treat dengue disease. Recently, RNA-dependent RNA polymerase (RdRp), a class of polymerases involved in the synthesis of complementary RNA strands using single-stranded RNA, has been proposed as a promising drug target. Hence, we screened new molecules against DENV RdRp using our previously constructed virtual screening method. Mol-5, [1,2,4]triazolo[1,5-a]pyrimidine derivative, was screened out from an antiviral compound library (~8000 molecules). Using biophysical methods, we confirmed the direct interactions between mol-5 and purified DENV RdRp protein. In luciferase assay, mol-5 inhibited NS5-RdRp activity with an IC₅₀ value of 1.28 ± 0.2 μM. In the cell-based cytopathic effect (CPE) assay, mol-5 inhibited DENV2 infectivity with an EC₅₀ value of 4.5 ± 0.08 μM. Mol-5 also potently inhibited DENV2 RNA replication as observed in immunofluorescence assay and qRT-PCR. Both the viral structural (E) and non-structural (NS1) proteins of DENV2 were dose-dependently decreased by treatment with mol-5 (2.5–10 μM). Mol-5 treatment suppressed DENV2-induced inflammation in host cells, but had no direct effect on host defense (JAK/STAT-signaling pathway). These results demonstrate that mol-5 could be a novel RdRp inhibitor amenable for further research and development.

Role of Vacha (Acorus calamus Linn.) in Neurological and Metabolic Disorders: Evidence from Ethnopharmacology, Phytochemistry, Pharmacology and Clinical Study

Vacha (Acorus calamus Linn. (Acoraceae)) is a traditional Indian medicinal herb, which is practiced to treat a wide range of health ailments, including neurological, gastrointestinal, respiratory, metabolic, kidney, and liver disorders. The purpose of this paper is to provide a comprehensive up-to-date report on its ethnomedicinal use, phytochemistry, and pharmacotherapeutic potential, while identifying potential areas for further research. To date, 145 constituents have been isolated from this herb and identified, including phenylpropanoids, sesquiterpenoids, and monoterpenes. Compelling evidence is suggestive of the biopotential of its various extracts and active constituents in several metabolic and neurological disorders, such as anticonvulsant, antidepressant, antihypertensive, anti-inflammatory, immunomodulatory, neuroprotective, cardioprotective, and anti-obesity effects. The present extensive literature survey is expected to provide insights into the involvement of several signaling pathways and oxidative mechanisms that can mitigate oxidative stress, and other indirect mechanisms modulated by active biomolecules of A. calamus to improve neurological and metabolic disorders.

Finding small molecules with pan-serotype activity to target Dengue non-structural protein 1

Dengue virus (DENV) is a mosquito-borne flavivirus which causes Dengue fever and severe Dengue. It exists as four antigenically different serotypes that are further classified into genotypes with varying degrees of pathogenicity. The non-structural protein 1 (NS1) of DENV has an important role in viral replication and its pathogenesis. NS1 is also considered as an important diagnostic marker for Dengue pathogenesis. To the best of our knowledge, there are no attempts to explore small molecule drugs to target the NS1 of all the serotypes. Here, we have taken the DENV 2 NS1 crystal structure as a reference to model the NS1 structure of the other three serotypes. Once the active site of the NS1 is identified, virtual screening of plant flavonoids is carried out against the NS1 of all the four serotypes. The top 200 molecules in the library with high binding affinities are further analysed to find the common ones having comparable affinities to all the four serotypes. The predicted common flavonoids are subjected to ADMET profiling to further select the most potential molecules that can be used to target NS1 of all the four serotypes.

The Antiviral Effect of Indonesian Medicinal Plant Extracts Against Dengue Virus In Vitro and In Silico

Dengue infections are still a worldwide burden, especially in Indonesia. There is no specific medication against the dengue virus. Recently, many types of research have been conducted to discover a new drug for dengue virus using natural resource extracts. Indonesia, as a tropical country, has a wide biodiversity. There are several medicinal plants in Indonesia that are believed to possess anti-dengue activity, such as Myristica fatua, Cymbopogon citratus, and Acorus calamus plants. We conducted an in vitro laboratory experiment of several extracts from Indonesian herbs combined with in silico analysis. The extracts were evaluated for safety and antiviral activity in Huh7it-1 cell lines, using a single dose of 20 µg/mL and dose-dependent (5, 10, 20, 40, 80 and 160 µg/mL) of plant extracts against dengue virus serotype 2 (DENV-2) NGC strain. The DMSO 0.1% was used as a negative control. The cytotoxic aspect was assessed by counting the cell viability, while the antiviral activity was calculated by counting the average inhibition. The selectivity index (SI) of plant extracts were performed from a ratio of CC₅₀/EC₅₀ value. In silico analysis was conducted to determine the free energy of binding between NS5 of dengue virus with bioactive compounds contained in Myristica fatua, Cymbopogon citratus and Acorus calamus extract plants. We determined that all extracts were not toxic against Huh7it-1 cell lines. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed inhibition of DENV-2 at a dose of 20 µg/mL to 96.5%, 98.9%, and 122.7%, respectively. The dose-dependent effects showed that M. fatua has the best inhibition activity towards DENV-2. Molecular docking result showed that artesunic acid within M. fatua has the best free energy of binding (-7.2 kcal/mol), followed by homoegonol (-7.1 kcal/mol) which was slightly different from artesunic acid among others. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed prospective anti-dengue activities both in vitro and in silico. Future research should be conducted to find the pure extracts of all useful herbs as a new candidate of antiviral drug.

Recent update on anti-dengue drug discovery

Dengue is the most important arthropod-borne viral disease of humans, with more than half of the global population living in at-risk areas. Despite the negative impact on public health, there are no antiviral therapies available, and the only licensed vaccine, Dengvaxia^®, has been contraindicated in children below nine years of age. In an effort to combat dengue, several small molecules have entered into human clinical trials. Here, we review anti-DENV molecules and their drug targets that have been published within the past five years (2014-2018). Further, we discuss their probable mechanisms of action and describe a role for classes of clinically approved drugs and also an unclassified class of anti-DENV agents. This review aims to enhance our understanding of novel agents and their cognate targets in furthering innovations in the use of small molecules for dengue drug therapies.

Q63, a novel DENV2 RdRp non-nucleoside inhibitor, inhibited DENV2 replication and infection

Dengue virus (DENV) annually infects 400 million people worldwide. Unfortunately, there is lack of widely protective vaccine or drugs against DENV. The viral RNA-dependent RNA polymerase (RdRp) of NS5 protein is highly conserved among different DENV subtypes, thus presenting itself as an attractive target for drug design. In the current research, SPRi was performed to screen compounds against DENV2 RdRp and 5(1H)-Quinazolinone,2-(4-bromophenyl)-2,3,4,6,7,8-hexahydro-7,7-dimethyl-1,3-diphenyl (Q63) was successfully screened out with a KD of 0.9 μM. Then, ITC and molecular docking assay was performed to access the binding mechanism between Q63 and DENV2 RdRp. Meanwhile, Q63 also decreased the intermediate dsRNA production, which was the product of RdRp. Further the antiviral effects of Q63 were evaluated on mosquito C6/36 cells and mammalian BHK-21 cells. Q63 reduced CPE and cell toxicity effect after DENV2 infection on C6/36 and BHK-21 cells, with an EC₅₀ of 2.08 μM. Time of addition assay revealed that Q63 affected the early genome RNA replication stage, including genome RNA replication. In addition, Q63 down-regulated STAT1 phosphorylation, ISG15 and ISG54 after DENV2 infection. In summary, Q63 was found to be a novel RdRp non-nucleoside inhibitor and a potential lead compound for coping with DENV infectious disease in the future.