Cinnamic acid inhibits Zika virus by inhibiting RdRp activity

Exploring the Antiviral Potential of Esters of Cinnamic Acids with Quercetin

Severe acute respiratory syndrome-related Coronavirus 2 (SARS-CoV-2) has infected more than 762 million people to date and has caused approximately 7 million deaths all around the world, involving more than 187 countries. Although currently available vaccines show high efficacy in preventing severe respiratory complications in infected patients, the high number of mutations in the S proteins of the current variants is responsible for the high level of immune evasion and transmissibility of the virus and the reduced effectiveness of acquired immunity. In this scenario, the development of safe and effective drugs of synthetic or natural origin to suppress viral replication and treat acute forms of COVID-19 remains a valid therapeutic challenge. Given the successful history of flavonoids-based drug discovery, we developed esters of substituted cinnamic acids with quercetin to evaluate their in vitro activity against a broad spectrum of Coronaviruses. Interestingly, two derivatives, the 3,4-methylenedioxy 6 and the ester of acid 7, have proved to be effective in reducing OC43-induced cytopathogenicity, showing interesting EC50s profiles. The ester of synaptic acid 7 in particular, which is not endowed with relevant cytotoxicity under any of the tested conditions, turned out to be active against OC43 and SARS-CoV-2, showing a promising EC50. Therefore, said compound was selected as the lead object of further analysis. When tested in a yield reduction, assay 7 produced a significant dose-dependent reduction in viral titer. However, the compound was not virucidal, as exposure to high concentrations of it did not affect viral infectivity, nor did it affect hCoV-OC43 penetration into pre-treated host cells. Additional studies on the action mechanism have suggested that our derivative may inhibit viral endocytosis by reducing viral attachment to host cells.

ICP-MS and fluorescence dual-mode detection of ZIKV-RNA based on quantum dot labeling with hybridization chain reaction

The detection of Zika virus (ZIKV) is of great significance to human life and health. Herein, we presented an ICP-MS and fluorescent dual-mode sensor for quantitative analysis of Zika virus RNA fragments (ZIKV-RNA), which employed quantum dots (QDs) as signal tags and combined with hybridization chain reaction (HCR). The dual-mode sensor realized cross-checking of the analysis results and improved the assay accuracy. Firstly, the single-stranded DNA (ssDNA) was anchored on the surface of magnetic beads (MBs). Afterward, HCR was conducted with probe DNA-CdSe quantum dots conjugates (pDNA-QDs) and link DNA (lDNA), producing the MBs-ssDNA-[pDNA-QDs-lDNA]n conjugates. In the presence of target ZIKV-RNA, a strand displacement reaction occurred, leading to the dissociation of the [pDNA-QDs-lDNA]n labels from the conjugates into the solution. Finally, the signal intensity was detected using ICP-MS and fluorescence analysis, with achieved limits of detection of 131 pM and 152 pM, respectively. The inter-assay RSD values of fluorescence and ICP-MS were 3.94 % and 4.26 % at 10 nM level, respectively, showing that the method had good precision. This method showed high selectivity and was applied to the analysis of biological fluids. There was no significant difference between the results of ICP-MS modes and fluorescence mode. This method offers a new strategy for sensitivity analysis of ZIKV-RNA and exhibits promise in clinical applications for diagnosis.

Zinc oxide nanoparticles functionalized with cinnamic acid for targeting dental pathogens receptor and modulating apoptotic genes in human oral epidermal carcinoma KB cells

BACKGROUND

Oral diseases are often attributed to dental pathogens such as S. aureus, S. mutans, E. faecalis, and C. albicans. In this research work, a novel approach was employed to combat these pathogens by preparing zinc oxide nanoparticles (ZnO NPs) capped with cinnamic acid (CA) plant compounds.

METHODS

The synthesized ZnO-CA NPs were characterized using SEM, FTIR, and XRD to validate their composition and structural features. The antioxidant activity of ZnO-CA NPs was confirmed using DPPH and ABTS free radical scavenging assays. The antimicrobial effects of ZnO-CA NPs were validated using a zone of inhibition assay against dental pathogens. Autodock tool was used to identify the interaction of cinnamic acid with dental pathogen receptors.

RESULTS

ZnO-CA NPs exhibited potent antioxidant activity in both DPPH and ABTS assays, suggesting their potential as powerful antioxidants. The minimal inhibitory concentration of ZnO-CA NPs against dental pathogens was found 25 µg/mL, indicating their effective antimicrobial properties. Further, ZnO-CA NPs showed better binding affinity and amino acid interaction with dental pathogen receptors. Also, the ZnO-CA NPs exhibited dose-dependent (5 µg/mL, 15 µg/mL, 25 µg/mL, and 50 µg/mL) anticancer activity against Human Oral Epidermal Carcinoma KB cells. The mechanism of action of apoptotic activity of ZnO-CA NPs on the KB cells was identified through the upregulation of BCL-2, BAX, and P53 genes.

CONCLUSIONS

This research establishes the potential utility of ZnO-CA NPs as a promising candidate for dental applications. The potent antioxidant, anticancer, and effective antimicrobial properties of ZnO-CA NPs make them a valuable option for combating dental pathogens.

Cinnamic Acid and Caffeic Acid Effects on Gastric Tight Junction Proteins Analyzed in Xenopus laevis Oocytes

Analysis of secondary plant compounds for the development of novel therapies is a common focus of experimental biomedicine. Currently, multiple health-supporting properties of plant-derived molecules are known but still information on many mechanisms is scarce. Cinnamic acid and caffeic acid are two of the most abundant polyphenols in human dietary fruits and vegetables. In this study, we investigated cinnamic acid and caffeic acid effects on the gastric barrier, which is primarily provided by members of the transmembrane tight junction protein family of claudins. The Xenopus laevis oocyte has been established, in recent years, as a heterologous expression system for analysis of transmembrane tight junction protein interactions, by performing paired oocyte experiments to identify an effect on protein-protein interactions, in vitro. In our current study, human gastric claudin-4, -5, and -18.2. were expressed and detected in the oocyte plasma membrane by freeze fracture electron microscopy and immunoblotting. Oocytes were paired and incubated with 100 µM or 200 µM cinnamic acid or caffeic acid, or Ringer's solution, respectively. Caffeic acid showed no effect on the contact area strength of paired oocytes but led to an increased contact area size. In contrast, cinnamic acid-incubated paired oocytes revealed a reduced contact area and a strengthening effect on the contact area was identified. These results may indicate that caffeic acid and cinnamic acid both show an effect on gastric barrier integrity via direct effects on tight junction proteins.

Simple phenylpropanoids: recent advances in biological activities, biosynthetic pathways, and microbial production

Covering: 2000 to 2023Simple phenylpropanoids are a large group of natural products with primary C6-C3 skeletons. They are not only important biomolecules for plant growth but also crucial chemicals for high-value industries, including fragrances, nutraceuticals, biomaterials, and pharmaceuticals. However, with the growing global demand for simple phenylpropanoids, direct plant extraction or chemical synthesis often struggles to meet current needs in terms of yield, titre, cost, and environmental impact. Benefiting from the rapid development of metabolic engineering and synthetic biology, microbial production of natural products from inexpensive and renewable sources provides a feasible solution for sustainable supply. This review outlines the biological activities of simple phenylpropanoids, compares their biosynthetic pathways in different species (plants, bacteria, and fungi), and summarises key research on the microbial production of simple phenylpropanoids over the last decade, with a focus on engineering strategies that seem to hold most potential for further development. Moreover, constructive solutions to the current challenges and future perspectives for industrial production of phenylpropanoids are presented.

Veratramine inhibits porcine epidemic diarrhea virus entry through macropinocytosis by suppressing PI3K/Akt pathway

Porcine epidemic diarrhea (PED) is a contagious intestinal disease caused by α-coronavirus porcine epidemic diarrhea virus (PEDV). At present, no effective vaccine is available to prevent the disease. Therefore, research for novel antivirals is important. This study aimed to identify the antiviral mechanism of Veratramine (VAM), which actively inhibits PEDV replication with a 50 % inhibitory concentration (IC50) of ∼5 µM. Upon VAM treatment, both PEDV-nucleocapsid (N) protein level and virus titer decreased significantly. The time-of-addition assay results showed that VAM could inhibit PEDV replication by blocking viral entry. Importantly, VAM could inhibit PEDV-induced phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) activity and further suppress micropinocytosis, which is required for PEDV entry. In addition, PI3K inhibitor LY294002 showed anti-PEDV activity by blocking viral entry as well. Taken together, VAM possessed anti-PEDV properties against the entry stage of PEDV by inhibiting the macropinocytosis pathway by suppressing the PI3K/Akt pathway. VAM could be considered as a lead compound for the development of anti-PEDV drugs and may be used during the viral entry stage of PEDV infection.

Therapeutic Study of Cinnamic Acid Derivative for Oxidative Stress Ablation: The Computational and Experimental Answers

This study aimed to examine the therapeutic activity of the cinnamic acid derivative KAD-7 (N'-(2,4-dichlorobenzylidene)-3-(4-methoxyphenyl) acrylohydrazide) on Fe2+-induced oxidative hepatic injury via experimental and computational models. In addition, the role of ATPase and ectonucleoside triphosphate diphosphohydrolase (ENTPDase) in the coordination of cellular signals is speculated upon to proffer suitable therapeutics for metabolic stress disorder upon their inhibition. While we know little about therapeutics with flexible dual inhibitors for these protein targets, this study was designed to screen KAD-7's (N'-(2,4-dichlorobenzylidene)-3-(4-methoxyphenyl) acrylohydrazide) inhibitory potential for both protein targets. We induced oxidative hepatic damage via the incubation of hepatic tissue supernatant with 0.1 mM FeSO4 for 30 min at 37 °C. We achieved the treatment by incubating the hepatic tissues with KAD-7 under the same conditions. The catalase (CAT), glutathione (GSH), malondialdehyde (MDA), ATPase, and ENTPDase activity were all measured in the tissues. We predicted how the drug candidate would work against ATPase and ENTPDase targets using molecular methods. When hepatic injury was induced, there was a significant decrease in the levels of the GSH, CAT, and ENTPDase (p < 0.05) activities. In contrast, we found a noticeable rise in the MDA levels and ATPase activity. KAD-7 therapy resulted in lower levels of these activities overall (p < 0.05), as compared to the control levels. We found the compound to have a strong affinity for ATPase (-7.1 kcal/mol) and ENTPDase (-7.4 kcal/mol), and a better chemical reactivity than quercetin. It also met all drug-likeness parameters. Our study shows that KAD-7 can protect the liver from damage caused by FeSO4 by reducing oxidative stress and purinergic actions. Our studies indicate that KAD-7 could be developed as a therapeutic option since it can flexibly inhibit both ATPase and ENTPDase.

Therapeutic Promises of Plant Metabolites against Monkeypox Virus: An In Silico Study

The monkeypox virus was still spreading in May 2022, with the first case identified in a person with travel ties to Nigeria. Using molecular docking-based techniques, we evaluated the efficiency of different bioactive chemicals obtained from plants against the monkeypox virus. A total of 56 plant compounds were evaluated for antimonekypox capabilities, with the top four candidates having a higher binding affinity than the control. We targeted the monkeypox profilin-like protein, which plays a key role in viral replication and assembly. Among the metabolites, curcumin showed the strongest binding affinity with a value of -37.43 kcal/mol, followed by gedunin (-34.89 kcal/mol), piperine (-34.58 kcal/mol), and coumadin (-34.14 kcal/mol). Based on ADME and toxicity assessments, the top four substances had no negative impacts. Furthermore, four compounds demonstrated resistance to deformability, which was corroborated by normal mode analysis. According to the bioactivity prediction study, the top compound target class was an enzyme, membrane receptor, and oxidoreductase. Furthermore, the study discovered that wortmannin, a gedunin analogue, can behave as an orthopoxvirus. The study found that these bioactive natural drug candidates could potentially work as monkeypox virus inhibitors. We recommended further experimental validation to confirm the promising findings of the study.

Indol-3-ylglyoxylamide as Privileged Scaffold in Medicinal Chemistry

In recent years, indolylglyoxylamide-based derivatives have received much attention due to their application in drug design and discovery, leading to the development of a wide array of compounds that have shown a variety of pharmacological activities. Combining the indole nucleus, already validated as a "privileged structure," with the glyoxylamide function allowed for an excellent template to be obtained that is suitable to a great number of structural modifications aimed at permitting interaction with specific molecular targets and producing desirable therapeutic effects. The present review provides insight into how medicinal chemists have elegantly exploited the indolylglyoxylamide moiety to obtain potentially useful drugs, with a particular focus on compounds exhibiting activity in in vivo models or reaching clinical trials. All in all, this information provides exciting new perspectives on existing data that can be useful in further design of indolylglyoxylamide-based molecules with interesting pharmacological profiles. The aim of this report is to present an update of collection data dealing with the employment of this moiety in the rational design of compounds that are able to interact with a specific target, referring to the last 20 years.

Design, synthesis, and biological evaluation of a series of new anthraquinone derivatives as anti-ZIKV agents

The major severe complications linked to Zika virus (ZIKV) cause the global public health problems, including microcephaly and other congenital abnormalities in newborns, and Guillain-Barré syndrome, meningoencephalitis, multi-organ failure in adults. However, neither approved vaccines nor drugs are available for ZIKV. In this study, we describe the design, synthesis and the anti-ZIKV activities of a series of anthraquinone analogs. Most of the newly synthesized compounds demonstrated moderate to excellent potency against ZIKV. Among all, compound 22, showed the most potent anti-ZIKV activity (EC₅₀ value from 1.33 μM to 5.72 μM) with low cytotoxicity (CC₅₀＞50 μM) in multiple cellular model. Importantly, 22 significantly improved the survival of ZIKV-infected mice (Ifnar1^-/-), alleviated ZIKV-associated pathological damages and suppressed the excessive inflammatory response and pyroptosis induced by ZIKV in vivo and in vitro. Furthermore, the molecular docking simulation analysis and the surface plasmon resonance results demonstrated the direct binding between 22 and ZIKV RdRp, and the mechanistic study revealed that 22 suppressed viral RNA synthesis by ZIKV NS5 in cells. Taken together, this study highlights that 22 may be a novel anti-ZIKV drug candidate and provides treatment options for ZIKV-associated diseases.

The Aqueous Leaf Extract of the Medicinal Herb Costus speciosus Suppresses Influenza A H1N1 Viral Activity under In Vitro and In Vivo Conditions

This study investigated the antiviral activity of aqueous leaf extract of Costus speciosus (TB100) against influenza A. Pretreatment of TB100 in RAW264.7 cells enhanced antiviral activity in an assay using the green fluorescence-expressing influenza A/Puerto Rico/8/1934 (H1N1) virus. The fifty percent effective concentration (EC50) and fifty percent cytotoxic concentration (CC50) were determined to be 15.19 ± 0.61 and 117.12 ± 18.31 µg/mL, respectively, for RAW264.7 cells. Based on fluorescent microscopy, green fluorescence protein (GFP) expression and viral copy number reduction confirmed that TB100 inhibited viral replication in murine RAW264.7 and human A549 and HEp2 cells. In vitro pretreatment with TB100 induced the phosphorylation of transcriptional activators TBK1, IRF3, STAT1, IKB-α, and p65 associated with interferon pathways, indicating the activation of antiviral defenses. The safety and protective efficacy of TB100 were assessed in BALB/c mice as an oral treatment and the results confirmed that it was safe and effective against influenza A/Puerto Rico/8/1934 (H1N1), A/Philippines/2/2008 (H3N2), and A/Chicken/Korea/116/2004 (H9N2). High-performance liquid chromatography of aqueous extracts led to the identification of cinnamic, caffeic, and chlorogenic acids as potential chemicals for antiviral responses. Further confirmatory studies using these acids revealed that each of them confers significant antiviral effects against influenza when used as pretreatment and enhances the antiviral response in a time-dependent manner. These findings suggest that TB100 has the potential to be developed into an antiviral agent that is effective against seasonal influenza.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (Paxlovid^TM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Evaluation of therapeutic potentials of selected phytochemicals against Nipah virus, a multi-dimensional in silico study

The current study attempted to evaluate the potential of fifty-three (53) natural compounds as Nipah virus attachment glycoprotein (NiV G) inhibitors through in silico molecular docking study. Pharmacophore alignment of the four (4) selected compounds (Naringin, Mulberrofuran B, Rutin and Quercetin 3-galactoside) through Principal Component Analysis (PCA) revealed that common pharmacophores, namely four H bond acceptors, one H bond donor and two aromatic groups were responsible for the residual interaction with the target protein. Out of these four compounds, Naringin was found to have the highest inhibitory potential ( - 9.19 kcal mol^-1) against the target protein NiV G, when compared to the control drug, Ribavirin ( - 6.95 kcal mol^-1). The molecular dynamic simulation revealed that Naringin could make a stable complex with the target protein in the near-native physiological condition. Finally, MM-PBSA (Molecular Mechanics-Poisson-Boltzmann Solvent-Accessible Surface Area) analysis in agreement with our molecular docking result, showed that Naringin ( - 218.664 kJ mol^-1) could strongly bind with the target protein NiV G than the control drug Ribavirin ( - 83.812 kJ mol^-1).

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03595-y.

Natural Products and Derivatives as Potential Zika virus Inhibitors: A Comprehensive Review

Zika virus (ZIKV) is an arbovirus whose infection in humans can lead to severe outcomes. This article reviews studies reporting the anti-ZIKV activity of natural products (NPs) and derivatives published from 1997 to 2022, which were carried out with NPs obtained from plants (82.4%) or semisynthetic/synthetic derivatives, fungi (3.1%), bacteria (7.6%), animals (1.2%) and marine organisms (1.9%) along with miscellaneous compounds (3.8%). Classes of NPs reported to present anti-ZIKV activity include polyphenols, triterpenes, alkaloids, and steroids, among others. The highest values of the selectivity index, the ratio between cytotoxicity and antiviral activity (SI = CC₅₀/EC₅₀), were reported for epigallocatechin gallate (SI ≥ 25,000) and anisomycin (SI ≥ 11,900) obtained from Streptomyces bacteria, dolastane (SI = 1246) isolated from the marine seaweed Canistrocarpus cervicorni, and the flavonol myricetin (SI ≥ 862). NPs mostly act at the stages of viral adsorption and internalization in addition to presenting virucidal effect. The data demonstrate the potential of NPs for developing new anti-ZIKV agents and highlight the lack of studies addressing their molecular mechanisms of action and pre-clinical studies of efficacy and safety in animal models. To the best of our knowledge, none of the active compounds has been submitted to clinical studies.

Discovery of ZFD-10 of a pyridazino[4,5-b]indol-4(5H)-one derivative as an anti-ZIKV agent and a ZIKV NS5 RdRp inhibitor

Zika virus (ZIKV) infection is associated with the birth defect microcephaly and Guillain-Barré syndrome in adults. There is no approved vaccine or specific antiviral agent against ZIKV. ZFD-10, a novel structural skeleton of 1H-pyridazino[4,5-b]indol-4(5H)-one, was firstly synthesized and discovered to be a potent anti-ZIKV inhibitor with very low cytotoxicity. ZFD-10's anti-ZIKV potency is independent of cell lines and ZFD-10 mainly targets the post-entry stages of ZIKV life cycle. Time-of-addition and time-of-withdrawal assays showed that 10 μM ZFD-10 displayed the ability to decrease mainly at the RNA level and weakly the viral progeny particle load. Furthermore, ZFD-10 could protect ZIKV NS5 from thermal unfolding and aggregation and increase the Tagg value of ZIKV NS5 protein from 44.6 to 49.3 °C, while ZFD-10 dose-dependently inhibits ZIKV NS5 RdRp activity using in vitro RNA polymerase assays. Molecular docking study suggests that ZFD-10 affects RdRp enzymatic function through interfering with the fingers and thumb subdomains. These results supported that ZFD-10's cell-based anti-ZIKV activity is related to its anti-RdRp activity of ZIKV NS5. The in vivo anti-ZIKV study shows that the middle-dose (4.77 mg/kg/d) of ZFD-10 protected mice from ZIKV infection and the viral loads of the blood, liver, kidney and brain in the middle-dose and high-dose (9.54 mg/kg/d) were significantly reduced compared to those of the ZIKV control. These results confirm that ZFD-10 has a certain antiviral effect against ZIKV infection in vivo.

Piperazine-derived small molecules as potential Flaviviridae NS3 protease inhibitors. In vitro antiviral activity evaluation against Zika and Dengue viruses

Since 2011 Direct Acting antivirals (DAAs) drugs targeting different non-structural (NS) viral proteins (NS3, NS5A or NS5B inhibitors) have been approved for clinical use in HCV therapies. However, currently there are not licensed therapeutics to treat Flavivirus infections and the only licensed DENV vaccine, Dengvaxia, is restricted to patients with preexisting DENV immunity. Similarly to NS5 polymerase, the NS3 catalytic region is evolutionarily conserved among the Flaviviridae family sharing strong structural similarity with other proteases belonging to this family and therefore is an attractive target for the development of pan-flavivirus therapeutics. In this work we present a library of 34 piperazine-derived small molecules as potential Flaviviridae NS3 protease inhibitors. The library was developed through a privileged structures-based design and then biologically screened using a live virus phenotypic assay to determine the half-maximal inhibitor concentration (IC₅₀) of each compound against ZIKV and DENV. Two lead compounds, 42 and 44, with promising broad-spectrum activity against ZIKV (IC₅₀ 6.6 µM and 1.9 µM respectively) and DENV (IC₅₀ 6.7 µM and 1.4 µM respectively) and a good security profile were identified. Besides, molecular docking calculations were performed to provide insights about key interactions with residues in NS3 proteases' active sites.

Specialized metabolites from plants as a source of new multi-target antiviral drugs: a systematic review

Viral infections have always been the main global health challenge, as several potentially lethal viruses, including the hepatitis virus, herpes virus, and influenza virus, have affected human health for decades. Unfortunately, most licensed antiviral drugs are characterized by many adverse reactions and, in the long-term therapy, also develop viral resistance; for these reasons, researchers have focused their attention on investigating potential antiviral molecules from plants. Natural resources indeed offer a variety of specialized therapeutic metabolites that have been demonstrated to inhibit viral entry into the host cells and replication through the regulation of viral absorption, cell receptor binding, and competition for the activation of intracellular signaling pathways. Many active phytochemicals, including flavonoids, lignans, terpenoids, coumarins, saponins, alkaloids, etc., have been identified as potential candidates for preventing and treating viral infections. Using a systematic approach, this review summarises the knowledge obtained to date on the in vivo antiviral activity of specialized metabolites extracted from plant matrices by focusing on their mechanism of action.

Antiviral effects of the fused tricyclic derivatives of indoline and imidazolidinone on ZIKV infection and RdRp activities of ZIKV and DENV

The prevalence and ravages of Zika virus (ZIKV) seriously endanger human health, especially causing significant neurological defects in both neonates as pediatric microcephaly and adults as Guillain-Barré syndrome. In this work, we studied anti-ZIKV effects of the fused tricyclic derivatives of indoline and imidazolidinone and discovered that some of them are valuable leads for drug discovery of anti-ZIKV agents. The current results show that certain compounds are broad-spectrum inhibitors of ZIKV- and dengue virus (DENV)-infection while distinctive compounds are selective ZIKV inhibitors or selective DENV inhibitors. Compounds of 12, 17 and 28 are more active against Asian ZIKV SZ-VIV01 strain than African ZIKV MR766 strain. It is valued that silylation makes six TBS compounds of 4-nitrophenyl hydrazine series and phenyl hydrazine series more active against ZIKV infection than their phenols. Time-of-addition and withdrawal studies indicate that compound 12 majorly acts on post-infection of RNA synthesis stage of ZIKV life cycle. Moreover, compounds of 12, 17 and 18 are anti-ZIKV agents with the inhibitory activities to ZIKV NS5 RdRp while 12 doesn't inhibit DENV infection even though it is a DENV RdRp inhibitor, 17 is an active agent against DENV infection but is only a weak DENV NS5 RdRp inhibitor, and 28 is inactive against DENV infection and not a DENV NS5 RdRp inhibitor. As a result, a compound's antiviral difference between ZIKV and DENV is not always related to anti-RdRp difference between ZIKV RdRp and DENV RdRp, and structural features of a compound play important roles in executing antiviral and anti-RdRp functions. Further discovery of highly potent broad-spectrum or selective agents against infection by ZIKV and DENV will be facilitated.

Sofosbuvir and its tri-phosphate metabolite inhibit the RNA-dependent RNA polymerase activity of non-structural protein 5 from the Kyasanur forest disease virus

Kyasanur forest disease is a neglected zoonotic disease caused by a single-stranded RNA-based flavivirus, the incidence of which was first recorded in 1957 in the Southern part of India. Kyasanur forest disease virus is transmitted to monkeys and humans through the infected tick bite of Haemophysalis spinigera. Kyasanur forest disease is a febrile illness, which in severe cases, results in neurological complications leading to mortality. The current treatment regimens are symptomatic and supportive, and no targeted therapies are available for this disease. In this study, we evaluated the ability of FDA-approved drugs sofosbuvir (and its active metabolite) and Dasabuvir to inhibit the RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus. NS5 protein containing the N-terminal methyl transferase domain and C-terminal RNA-dependent RNA polymerase domain was expressed in Escherichia coli, and RNA-dependent RNA polymerase activity was demonstrated with the purified protein. The RNA-dependent RNA polymerase assay conditions were optimized, followed by the determination of apparent K_m,ATP to validate the enzyme preparation. Half maximal-inhibitory concentrations against RNA-dependent RNA polymerase activity were determined for Sofosbuvir and its active metabolite. Dasabuvir did not show detectable inhibition with the tested conditions. This is the first demonstration of the inhibition of RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus with small molecule inhibitors. These initial findings can potentially facilitate the discovery and development of targeted therapies for treating Kyasanur forest disease.

Transcriptomic reveals the ferroptosis features of host response in a mouse model of Zika virus infection

Zika virus (ZIKV) is a neurotropic flavivirus. The outbreak of ZIKV in 2016 created a global health emergency. However, the underlying pathogenic mechanisms remain elusive. We investigated the host response features of in vivo replication in a mouse model of ZIKV infection, by performing a series of transcriptomic and bioinformatic analyses of ZIKV and mock-infected brain tissue. Tissue damage, inflammatory cells infiltration and high viral replication were observed in the brain tissue of ZIKV infected mice. RNA-Seq of the brain indicated the activation of ferroptosis pathways. Enrichment analysis of ferroptosis regulators revealed their involvement in pathways such as mineral absorption, fatty acid biosynthesis, fatty acid degradation, PPAR signaling pathway, peroxidase, and adipokinesine signalling pathway. We then identified 12 interacted hub ferroptosis regulators (CYBB, HMOX1, CP, SAT1, TF, SLC39A14, FTL, LPCAT3, FTH1, SLC3A2, TP53, and SLC40A1) that were related to the differential expression of CD8⁺ T cells, microglia and monocytes. CYBB, HMOX1, SALT, and SLAC40A1 were selected as potential biomarkers of ZIKV infection. Finally, we validated our results using RT-qPCR and outside available datasets. For the first time, we proposed a possible mechanism of ferroptosis in brain tissue infected by ZIKV in mice and identified the four key ferroptosis regulators.

Green Synthesized Zinc Oxide Nanoparticles Based on Cestrum diurnum L. of Potential Antiviral Activity against Human Corona 229-E Virus

SARS-CoV-2 has caused more than 596 million infections and 6 million fatalities globally. Looking for urgent medication for prevention, treatment, and rehabilitation is obligatory. Plant extracts and green synthesized nanoparticles have numerous biological activities, including antiviral activity. HPLC analysis of C. dirnum L. leaf extract showed that catechin, ferulic acid, chlorogenic acid, and syringic acid were the most major compounds, with concentrations of 1425.16, 1004.68, 207.46, and 158.95 µg/g, respectively. Zinc nanoparticles were biosynthesized using zinc acetate and C. dirnum extract. TEM analysis revealed that the particle size of ZnO-NPs varied between 3.406 and 4.857 nm. An XRD study showed the existence of hexagonal crystals of ZnO-NPs with an average size of 12.11 nm. Both ZnO-NPs (IC₅₀ = 7.01 and CC₅₀ = 145.77) and C. dirnum L. extract (IC₅₀ = 61.15 and CC₅₀ = 145.87 µg/mL) showed antiviral activity against HCOV-229E, but their combination (IC₅₀ = 2.41 and CC₅₀ = 179.23) showed higher activity than both. Molecular docking was used to investigate the affinity of some metabolites against the HCOV-229E main protease. Chlorogenic acid, solanidine, and catchin showed high affinity (-7.13, -6.95, and -6.52), compared to the ligand MDP (-5.66 Kcal/mol). Cestrum dinurum extract and ZnO-NPs combination should be subjected to further studies to be used as an antiviral drug.

Novel Therapeutic Nutrients Molecules That Protect against Zika Virus Infection with a Special Note on Palmitoleate

Zika virus (ZIKV) is a Flavivirus from the Flaviviridae family and a positive-sense single strand RNA virus. ZIKV infection can cause a mild infection to the mother but can be vertically transmitted to the developing fetus, causing congenital anomalies. The prevalence of ZIKV infections was relatively insignificant with sporadic outbreaks in the Asian and African continents until 2006. However, recent epidemic in the Caribbean showed significant increased incidence of Congenital Zika Syndrome. ZIKV infection results in placental pathology which plays a crucial role in disease transmission from mother to fetus. Currently, there is no Food and Drug Administration (FDA) approved vaccine or therapeutic drug against ZIKV. This review article summarizes the recent advances on ZIKV transmission and diagnosis and reviews nutraceuticals which can protect against the ZIKV infection. Further, we have reviewed recent advances related to the novel therapeutic nutrient molecules that have been shown to possess activity against Zika virus infected cells. We also review the mechanism of ZIKV-induced endoplasmic reticulum and apoptosis and the protective role of palmitoleate (nutrient molecule) against ZIKV-induced ER stress and apoptosis in the placental trophoblasts.

Identification of 6ω-cyclohexyl-2-(phenylamino carbonylmethylthio)pyrimidin-4(3H)-ones targeting the ZIKV NS5 RNA dependent RNA polymerase

Zika virus (ZIKV), a mosquito-borne flavivirus, is a global health concern because of its association with severe neurological disorders such as neonatal microcephaly and adult Guillain-Barre syndrome. Although many efforts have been made to combat ZIKV infection, there is currently no approved vaccines or antiviral drugs available and there is an urgent need to develop effective anti-ZIKV agents. In this study, 26 acetylarylamine-S-DACOs derivatives were prepared, and eight of them were found to have inhibitory activity against Zika virus. Among these substances, 2-[(4-cyclohexyl-5-ethyl-6-oxo-1,6-dihydropyrimidin-2-yl)thio]-N-(3,5-difluorophenyl)acetamide (4w) with the best anti-ZIKV activity was selected for in-depth study of antiviral activity and mechanism of action. Here, we discovered 4w targeted on the ZIKV NS5 RNA -dependent RNA polymerase (RdRp), which exhibited good in vitro antiviral activity without cell species specificity, both at the protein level and at the RNA level can significantly inhibit ZIKV replication. Preliminary molecular docking studies showed that 4w preferentially binds to the palm region of NS5A RdRp through hydrogen bonding with residues such as LYS468, PHE466, GLU465, and GLY467. ZIKV NS5 RdRp enzyme activity experiment showed that 4w could directly inhibit ZIKV RdRp activity with EC₅₀ = 11.38 ± 0.51 μM. In antiviral activity studies, 4w was found to inhibit ZIKV RNA replication with EC₅₀ = 6.87 ± 1.21 μM. ZIKV-induced plaque formation was inhibited with EC₅₀ = 7.65 ± 0.31 μM. In conclusion, our study disclosed that acetylarylamine-S-DACOs is a new active scaffolds against ZIKV, among which compound 4w was proved to be a potent novel anti-ZIKV compound target ZIKV RdRp protein. These promising results provide a future prospective for the development of ZIKV RdRp inhibitors.

Cinnamic acid preserves against myocardial ischemia/reperfusion injury via suppression of NLRP3/Caspase-1/GSDMD signaling pathway

BACKGROUND

Cinnamic acid (CA) is an active organic acid compound extracted from Cinnamomi ramulus that has various biological activities. There is growing studies have shown that the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome significantly contributes to sterile inflammatory response and pyroptosis in myocardial ischemia/reperfusion injury (MI/RI). However, whether CA has any influence on NLRP3 inflammasome and pyroptosis during MI/RI are not fully elucidated.

PURPOSE

In the present study, we investigated whether NLRP3 inflammasome activation and pyroptosis were involved in the cardioprotective effect of CA against MI/RI.

METHODS

Male Sprague-Dawley rats were intragastrically administered either with CA (75 and 150 mg/kg, daily) or vehicle for 7 successive days prior to ligation of coronary artery, and then rats were subjected to ligation of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min to evoke MI/RI.

RESULTS

Our results demonstrated that CA could significantly improve cardiac diastolic function, decrease cardiac infarct size and myocardial injury enzymes, inhibit cardiomyocyte apoptosis, attenuate cardiac structure abnormality, and mitigate oxidative stress and inflammatory response. We also found that MI/RI activate NLRP3 inflammasome as evidenced by the upregulation levels of NLRP3, pro-caspase-1, caspase-1, and ASC proteins and mRNA. More importantly, MI/RI trigger pyroptosis as indicated by increased DNA fragmentation, membrane pore formation, and mitochondrial swelling as well as increased levels of pyroptosis-related proteins and mRNA, including GSDMD, N-GSDMD, IL-18, and IL-1β. As expected, all these deleterious alterations were prominently reversed by CA pretreatment.

CONCLUSIONS

These findings indicate that CA effectively protected cardiomyocytes against MI/RI by inhibiting NLRP3/Caspase-1/GSDMD signaling pathway, and it is worthy of more investigations for its therapeutic potential for extenuating ischemic heart disease.

A review of the phytochemical and pharmacological properties of Amauroderma rugosum

Amauroderma rugosum (AR) is a basidiomycete in the Ganodermataceae family that has been used traditionally to prevent epileptic attacks and constant crying in babies. However, AR has not been widely studied scientifically. In this review, we summarize the phytochemical components and pharmacological properties of AR that have been reported in the literature. Chemical analyses have revealed that the components of AR include sterols, flavonoids, fatty acids and esters, aromatic acids and esters, phenols, polysaccharides, and triterpenes. Pharmacological properties of AR include antioxidant, anti-inflammatory, neuroprotective, anti-cancer, anti-hyperlipidemic, anti-epileptic, and antibacterial effects. These findings suggest that AR and its bioactive ingredients have potential therapeutic applications, particularly for age-related diseases.

Cinnamic acid hybrids as anticancer agents: A mini-review

Cancer, as a long-lasting and dramatic disease, affects almost one-third of human beings globally. Chemotherapeutics play an important role in cancer treatment, but multidrug resistance and severe adverse effects have already become the main causes of failure in tumor chemotherapy. Therefore, it is an urgent need to develop novel chemotherapeutics. Cinnamic acid contains a ubiquitous α,β-unsaturated acid moiety presenting potential therapeutic effects in the treatment of cancer as these derivatives could act on cancer cells by diverse mechanisms of action. Accordingly, cinnamic acid derivatives are critical scaffolds in discovering novel anticancer agents. This review provides a comprehensive overview of cinnamic acid hybrids as anticancer agents. The structure-activity relationship, as well as the mechanisms of action, are also discussed, covering articles published from 2012 to 2021.

A review on structural genomics approach applied for drug discovery against three vector-borne viral diseases: Dengue, Chikungunya and Zika

Structural genomics involves the advent of three-dimensional structures of the genome encoded proteins through various techniques available. Numerous structural genomics research groups have been developed across the globe and they contribute enormously to the identification of three-dimensional structures of various proteins. In this review, we have discussed the applications of the structural genomics approach towards the discovery of potential lead-like molecules against the genomic drug targets of three vector-borne diseases, namely, Dengue, Chikungunya and Zika. Currently, all these three diseases are associated with the most important global public health problems and significant economic burden in tropical countries. Structural genomics has accelerated the identification of novel drug targets and inhibitors for the treatment of these diseases. We start with the current development status of the drug targets and antiviral drugs against these three diseases and conclude by describing challenges that need to be addressed to overcome the shortcomings in the process of drug discovery.

Cardioprotective activity of ethyl acetate extract of Cinnamomi Ramulus against myocardial ischemia/reperfusion injury in rats via inhibiting NLRP3 inflammasome activation and pyroptosis

BACKGROUND

NLRP3 inflammasome activation and pyroptosis play an important role in myocardial ischemia/reperfusion injury (MI/RI). Cinnamomi ramulus (CR), is an important folk medicinal plant in China, which derived from the dried twig of Cinnamomum cassia (L.) Presl, has function of "warming and tonifying heart yang", and traditionally utilized to treat the cold, blood-cold amenorrhea, phlegm, edema, arthralgia, and palpitations as well as improve blood circulation. The aqueous extract of C. ramulus was reported to show significant therapeutic potential for treating MI/RI. Whereas, there are no previous investigations in China or abroad has reported the cardioprotective effects and underlying mechanism of the ethyl acetate extract of C. ramulus (CREAE) and its bioactive substance cinnamic acid (CA) in triggering NLRP3 inflammasome activation and subsequent pyroptosis.

PURPOSE

The present study aimed to assess the cardioprotective function of CREAE and CA against the MI/RI in rats and involved the underlying mechanisms.

METHODS

The MI/RI model was established in male SD rats by occlusion of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min, respectively. The rats were intragastrically administered with CREAE (74 and 37 mg/kg) and CA (45 mg/kg) for 7 successive days before vascular ligation. The cardioprotective effects of CREAE and CA against myocardial injury of rats were detected by HE staining, TTC staining, echocardiograms, and myocardial enzymes detections. Serum levels of inflammatory factors, such as IL-6, IL-1β, and TNF-α, were analyzed by ELISA kits to evaluate the effects of CREAE and CA. The protein and gene expression levels of NLRP3 and the pyroptosis-related factors in heart tissue were conducted by western blot and RT-qPCR.

RESULTS

Our results showed that CREAE and CA decrease myocardial infarct size and improve cardiac function, mitigate myocardial damage, and repress inflammatory response in rats after I/R. Mechanistically, our results revealed that CREAE and CA can dramatically suppress the activation of NLRP3 inflammasome and subsequent cardiomyocyte pyroptosis in myocardial tissues that as evidenced by downregulating the protein and gene expressions of NLRP3, ASC, IL-1β, caspase-1, gasdermin D, and N-terminal GSDMD.

CONCLUSIONS

Our data indicated that CREAE and CA may attenuate MI/RI through suppression of NLRP3 inflammasome and subsequent pyroptosis-related signaling pathways.