Effective Antivirals Research Articles

Chemical Profile, Antibacterial, Antibiofilm, and Antiviral Activities of Pulicaria crispa Most Potent Fraction: An In Vitro and In Silico Study.

Infectious diseases caused by viruses and bacteria are a major public health concern worldwide, with the emergence of antibiotic resistance, biofilm-forming bacteria, viral epidemics, and the lack of effective antibacterial and antiviral agents exacerbating the problem. In an effort to search for new antimicrobial agents, this study aimed to screen antibacterial and antiviral activity of the total methanol extract and its various fractions of Pulicaria crispa (P. crispa) aerial parts. The P. crispa hexane fraction (HF) was found to have the strongest antibacterial effect against both Gram-positive and Gram-negative bacteria, including biofilm producers. The HF fraction reduced the expression levels of penicillin binding protein (PBP2A) and DNA gyrase B enzymes in Staphylococcus aureus and Pseudomonas aeruginosa, respectively. Additionally, the HF fraction displayed the most potent antiviral activity, especially against influenza A virus, affecting different stages of the virus lifecycle. Gas chromatography/mass spectrometry (GC/MS) analysis of the HF fraction identified 27 compounds, mainly belonging to the sterol class, with β-sitosterol, phytol, stigmasterol, and lupeol as the most abundant compounds. The in silico study revealed that these compounds were active against influenza A nucleoprotein and polymerase, PBP2A, and DNA gyrase B. Overall, this study provides valuable insights into the chemical composition and mechanism of action of the P. crispa HF fraction, which may lead to the development of more effective treatments for bacterial and viral infections.

Preventive effects of quercetin against foot-and-mouth disease virus in vitro and in vivo by inducing type I interferon.

Foot-and-mouth disease (FMD) is an acute contagious infectious disease that affects cloven-hoofed animals. Although current emergency FMD vaccines only take effect 7 days after vaccination, antiviral agents, such as quercetin, which is a common flavonoid, could reduce the spread of FMD virus (FMDV) during outbreaks. We investigated the in vitro and in vivo antiviral effects of quercetin against FMDV. Analysis of viral copy numbers showed that quercetin had a dose-dependent inhibitory effect on FMDV at concentrations between 19.5 and 1,250 μM in porcine cells. In addition, we observed a quercetin-induced interferon (IFN)-α protein and interferon-stimulated gene (ISG) upregulation in swine cells. Enzyme-linked immunosorbent assay of sera revealed that quercetin induces the production of IFN-α, IFN-β, IFN-γ, interleukin (IL)-12, and IL-15 in mice. Inoculation of mice with quercetin or a combination of quercetin with an inactivated FMD vaccine enhanced both the survival rate and neutralizing antibody titer. Therefore, we suggest the use of quercetin as a novel and effective antiviral agent for controlling FMDV infection; however, further investigation of its application in livestock is required.

Quinazoline Analogues as Antiviral Agents

Abstract: The current COVID-19 outbreak has created an urgent need for innovative and effective antiviral drugs. Quinazoline analogues are an effective antiviral agents. They have shown potent antiviral activity against various preclinical virus types. To date, various quinazoline analogues have been incorporated and tested for their antiviral activity. This review aims to bring together clinical knowledge of the numerous antiviral drug analogues that have been introduced based on their structural recital.

The use of trifluoromethyl tubercidin as a novel treatment of influenza in an overwhelmed health care setting: a correspondence

The use of trifluoromethyl tubercidin as a novel treatment of influenza in an overwhelmed health care setting: a correspondence

Etiology of viral induced acute liver failure and defensins as potential therapeutic agents in ALF treatment.

Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus.

Hypericum japonicum extract inhibited porcine epidemic diarrhea virus in vitro and in vivo.

Porcine epidemic diarrhea virus (PEDV) infection causes lethal watery diarrhea and high mortality in neonatal piglets, leading to huge economic losses in the global swine industry. Currently, the existing commercial vaccines cannot fully control PEDV, so it is urgent to develop effective antiviral agents to complement vaccine therapy. In the present study, we investigated the antiviral effect of Hypericum japonicum extract (HJ) against PEDV in vivo and in vitro. In in vitro assays, HJ could directly inactivate PEDV strains; moreover, it inhibited the proliferation of PEDV strains in Vero or IPI-FX cells at its non-cytotoxic concentrations. Time of addition assays revealed that HJ mainly inhibited PEDV at the later stages of the viral life cycle. In in vivo, compared with the model group, HJ could reduce the viral titers in the intestines of infected piglets, and improve their intestinal pathological, indicating that HJ could protect the newborn piglets from highly pathogenic PEDV variant infection. Furthermore, this effect may be related to the fact that HJ can not only directly inhibit viruses, but also regulate the structure of intestinal microbiota. In conclusion, our results indicate that Hypericum japonicum could inhibit PEDV replication in vitro and in vivo and might possess the potential to develop as the anti-PEDV drug.

Effect of temperature on hepatitis a virus and exploration of binding mode mechanism of phytochemicals from tinospora cordifolia: an insight into molecular docking, MM/GBSA, and molecular dynamics simulation study

The hepatitis A virus (HAV), which causes hepatitis A, is a contagious liver ailment. The infections are not specifically treated by any medications. Therefore, the development of less harmful, more effective and cost-effective antiviral agents are necessary. The present work highlighted the in-silico activity of phytocompounds from tinospora cordifolia against HAV. The binding interaction of HAV with the phytocompounds was analyzed through molecular docking. Molecular docking revealed that chasmanthin, malabarolide, menispermacide, tinosporaside, and tinosporinone compounds bind with HAV more efficiently than other compounds. Further evaluation using 100 ns molecular dynamics simulation, MM/GBSA and free energy landscape indicated that all phytocompounds studied here were found to be most promising drug candidate against hepatitis A virus. Our computational study will encourage promoting in further investigation for in vitro and in vivo clinical trials. Communicated by Ramaswamy H. Sarma

Prediction and Verification of Curcumin as a Potential Drug for Inhibition of PDCoV Replication in LLC-PK1 Cells.

Porcine deltacoronavirus (PDCoV) is an emerging swine enteropathogenic coronavirus (CoV) that causes lethal watery diarrhea in neonatal pigs and poses economic and public health burdens. Currently, there are no effective antiviral agents against PDCoV. Curcumin is the active ingredient extracted from the rhizome of turmeric, which has a potential pharmacological value because it exhibits antiviral properties against several viruses. Here, we described the antiviral effect of curcumin against PDCoV. At first, the potential relationships between the active ingredients and the diarrhea-related targets were predicted through a network pharmacology analysis. Twenty-three nodes and 38 edges were obtained using a PPI analysis of eight compound-targets. The action target genes were closely related to the inflammatory and immune related signaling pathways, such as the TNF signaling pathway, Jak-STAT signaling pathway, and so on. Moreover, IL-6, NR3C2, BCHE and PTGS2 were identified as the most likely targets of curcumin by binding energy and 3D protein-ligand complex analysis. Furthermore, curcumin inhibited PDCoV replication in LLC-PK1 cells at the time of infection in a dose-dependent way. In poly (I:C) pretreated LLC-PK1 cells, PDCoV reduced IFN-β production via the RIG-I pathway to evade the host's antiviral innate immune response. Meanwhile, curcumin inhibited PDCoV-induced IFN-β secretion by inhibiting the RIG-I pathway and reduced inflammation by inhibiting IRF3 or NF-κB protein expression. Our study provides a potential strategy for the use of curcumin in preventing diarrhea caused by PDCoV in piglets.

Andrographolide exerts anti-respiratory syncytial virus activity by up-regulating heme oxygenase-1 independent of interferon responses in human airway epithelial cells.

Respiratory syncytial virus (RSV) is the leading cause of mortality and morbidity in children under the age of five. Despite this, there is still a lack of safe and effective vaccines and antiviral agents for clinical use. Andrographolide exerts antiviral functions against a variety of viruses, but whether (and how) it exerts antiviral effects on RSV remains unclear. In vitro RSV infection models using A549 and 16HBE cell lines were established, and the effects of andrographolide on RSV were analyzed via RSV N gene load and proinflammatory cytokine levels. The RNA transcriptome was sequenced, and data were analyzed by R software. Andrographolide-related target genes were extracted via network pharmacology using online databases. Lentiviral transfection was applied to knockdown the heme oxygenase-1 gene (Hmox1, HO-1). Results showed that andrographolide suppressed RSV replication and attenuated subsequent inflammation. Network pharmacology and RNA sequencing analysis indicated that the hub gene HO-1 may play a pivotal role in the anti-RSV effects of andrographolide. Furthermore, andrographolide exerted antiviral effects against RSV partially by inducing HO-1 but did not activate the antiviral interferon response. Our findings demonstrated that andrographolide exerted anti-RSV activity by up-regulating HO-1 expression in human airway epithelial cells, providing novel insights into potential therapeutic targets and drug repurposing in RSV infection.

Water-Soluble Fullerene C60 Derivatives Are Effective Inhibitors of Influenza Virus Replication

The influenza virus genome features a very high mutation rate leading to the rapid selection of drug-resistant strains. Due to the emergence of drug-resistant strains, there is a need for the further development of new potent antivirals against influenza with a broad activity spectrum. Thus, the search for a novel, effective broad-spectrum antiviral agent is a top priority of medical science and healthcare systems. In this paper, derivatives based on fullerenes with broad virus inhibiting activities in vitro against a panel of influenza viruses were described. The antiviral properties of water-soluble fullerene derivatives were studied. It was demonstrated that the library of compounds based on fullerenes has cytoprotective activity. Maximum virus-inhibiting activity and minimum toxicity were found with compound 2, containing residues of salts of 2-amino-3-cyclopropylpropanoic acid (CC50 > 300 µg/mL, IC50 = 4.73 µg/mL, SI = 64). This study represents the initial stage in a study of fullerenes as anti-influenza drugs. The results of the study lead us conclude that five leading compounds (1-5) have pharmacological prospects.

9-Butyl-Harmol Exerts Antiviral Activity against Newcastle Disease Virus through Targeting GSK-3β and HSP90β.

The paramyxoviruses represent a large family of human and animal pathogens that cause significant health and economic burdens worldwide. However, there are no available drugs against the virus. β-carboline alkaloids are a family of naturally occurring and synthetic products with outstanding antiviral activities. Here, we examined the antiviral effect of a series of β-carboline derivatives against several paramyxoviruses, including Newcastle disease virus (NDV), peste des petits ruminants virus (PPRV), and canine distemper virus (CDV). Among these derivatives, 9-butyl-harmol was identified as an effective antiviral agent against these paramyxoviruses. Further, a genome-wide transcriptome analysis in combination with target validation strategies reveals a unique antiviral mechanism of 9-butyl-harmol through the targeting of GSK-3β and HSP90β. On one hand, NDV infection blocks the Wnt/β-catenin pathway to suppress the host immune response. 9-butyl-harmol targeting GSK-3β dramatically activates the Wnt/β-catenin pathway, which results in the boosting of a robust immune response. On the other hand, NDV proliferation depends on the activity of HSP90. The L protein, but not the NP protein or the P protein, is proven to be a client protein of HSP90β, rather than HSP90α. 9-butyl-harmol targeting HSP90β decreases the stability of the NDV L protein. Our findings identify 9-butyl-harmol as a potential antiviral agent, provide mechanistic insights into the antiviral mechanism of 9-butyl-harmol, and illustrate the role of β-catenin and HSP90 during NDV infection. IMPORTANCE Paramyxoviruses cause devastating impacts on health and the economy worldwide. However, there are no suitable drugs with which to counteract the viruses. We determined that 9-butyl-harmol could serve as a potential antiviral agent against paramyxoviruses. Until now, the antiviral mechanism of β-carboline derivatives against RNA viruses has rarely been studied. Here, we found that 9-butyl-harmol exerts dual mechanisms of antiviral action, with its antiviral activities being mediated by two targets: GSK-3β and HSP90β. Correspondingly, the interaction between NDV infection and the Wnt/β-catenin pathway or HSP90 is demonstrated in this study. Taken together, our findings shed light on the development of antiviral agents against paramyxoviruses, based on the β-carboline scaffold. These results present mechanistic insights into the polypharmacology of 9-butyl-harmol. Understanding this mechanism also deepens the host-virus interaction and reveals new drug targets for anti-paramyxoviruses.

Therapeutic strategies for human poxvirus infections: Monkeypox (mpox), smallpox, molluscipox, and orf.

Therapeutic and vaccine development for human poxvirus infections (e.g., monkeypox (mpox) virus, variola virus, molluscum contagiosum virus, orf virus) has been largely deserted, especially after the eradication of smallpox by 1980. Human mpox is a self-limited disease confined to Central and West Africa for decades. However, since April 2022, mpox has quickly emerged as a multi-country outbreak, urgently calling for effective antiviral agents and vaccines to control mpox. Here, this review highlights possible therapeutic options (e.g., tecovirimat, brincidofovir, cidofovir) and other strategies (e.g., vaccines, intravenous vaccinia immune globulin) for the management of human poxvirus infections worldwide.

The effect of vitamin C supplementation on favipiravir-induced oxidative stress and proinflammatory damage in livers and kidneys of rats

Background: Favipiravir (FPV), an effective antiviral agent, is a drug used to treat influenza and COVID-19 by inhibiting the RNA-dependent RNA polymerase (RdRp) of RNA viruses. FPV has the potential to increase oxidative stress and organ damage. The purpose of this study was to demonstrate the oxidative stress and inflammation caused by FPV in the liver and kidneys of rats, as well as to investigate the curative effects of vitamin C (VitC). Methods: A total of 40 Sprague–Dawley male rats were randomly and equally divided into the following five groups: 1st; Control, 2nd; FPV = 20 mg/kg, 3rd; FPV = 100 mg/kg, 4th; FPV = 20 mg/kg + VitC (150 mg/kg), and 5th; FPV = 100 mg/kg + VitC (150 mg/kg) groups. Rats were given either FPV (orally) or FPV plus VitC (intramuscular) for 14 days. Rat blood, liver, and kidney samples were collected at 15 days to be analyzed for oxidative and histological changes. Results: FPV administration resulted in an increase in proinflammatory cytokines (TNF-α and IL-6) in the liver and kidney, as well as oxidative and histopathologic damage. FPV increased TBARS levels significantly (p < .05) and decreased GSH and CAT levels in liver and kidney tissues but had no effect on SOD activity. VitC supplementation significantly reduced TNF-a, IL-6, and TBARS levels while increasing GSH and CAT levels (p < .05). Furthermore, VitC significantly attenuated FPV-induced histopathological alterations associated with oxidative stress and inflammation in the liver and kidney tissues (p < .05). Conclusion: FPV caused liver and kidney damage in rats. In contrast, co-administration of FPV with VitC improved FPV-induced oxidative, pro-inflammatory, and histopathological changes.

Antiviral Activity of Luteolin against Pseudorabies Virus In Vitro and In Vivo

Pseudorabies virus (PRV) can cause acute swine disease leading to economic losses worldwide and is a potential causative agent of viral encephalitis in humans. Although effective vaccines are available, an increasing number of variants have emerged in China, and identifying effective antiviral agents against PRV to prevent latent infection is essential. In this study, we assessed the antiviral activity of luteolin against PRV in vitro and in vivo. Luteolin was found to significantly inhibit PRV at a noncytotoxic concentration (70 μM), with an IC50 of 26.24 μM and a selectivity index of 5.64. Luteolin inhibited the virus at the replication stage and decreased the expression of viral mRNA and gB protein. Luteolin reduced the apoptosis of PRV-infected cells, improved the survival rate of mice after lethal challenge, reduced the viral loads in the liver, kidney, heart, lung, and brain, reduced brain lesions, and slowed inflammation and oxidation reactions. Our results showed that luteolin has promise as a new alternative antiviral drug for PRV infection.

Molecular docking and dynamics supported investigation of antiviral activity of Lichen metabolites of Roccella montagnei: an in silico and in vitro study

Lichens are symbiotic organisms that have been traditionally used for treating different kinds of ailments. As there are only a few reports on the antiviral activity of lichens, we thought of evaluating the anti-Herpes simplex virus-1 (HSV-1) activity of methanolic extract of Roccella montagnei and their isolated compounds. Fractionation of crude methanolic extract of Roccella montagnei by column chromatography isolated two pure compounds. Antiviral activity was assessed using a CPE inhibition assay at non-cytotoxic concentrations on Vero cells. Molecular docking and dynamics studies were carried out against Herpes simplex type-1 thymidine kinase to understand the binding interactions of the isolated compounds with reference to acyclovir. Isolated compounds were characterized as methyl orsellinate and montagnetol by spectral methods. Methanolic extract of Roccella montagnei exhibited an EC50 value of 56.51 µg/ml, while the compounds methyl orsellinate and montagnetol offered EC50 values of 13.50 µg/ml and 37.52 µg/ml, respectively, against HSV-1 viral infection on Vero cell lines. The selectively index (SI) of montagnetol (10.93) was found to be higher when compared to that of methyl orsellinate (5.55), indicating its better anti-HSV-1 activity. The docking and dynamics studies showed montagnetol was stable throughout the 100 ns, having better interactions and docking scores with HSV-1 thymidine kinase than methyl orsellinate, as well as the standard. To understand the mechanism of montagnetol’s anti-HSV-1 activity, more research is required, and this could lead to the discovery of new and effective antiviral agents. Communicated by Ramaswamy H. Sarma

Electrochemical oxidation of the increasingly used disinfectant benzalkonium chloride

AbstractBenzalkonium chloride (BAC) is a key ingredient in many cleaning and disinfectant products due to it being an effective antiviral and biocidal agent. Because of its prolific use, especially following the recent global COVID pandemic, increased levels of BAC have been found in the environment, in particular, in wastewater, where it has negative impacts due to its toxicity. This necessitates an effective treatment for BAC in wastewater to reduce its toxicity. In this work, electrochemical oxidation of BAC on a boron‐doped diamond anode was studied to successfully remove BAC. The electrochemical measurements performed at different current densities confirmed that BAC was completely oxidized within 20 min of treatment at 50 mA/cm2. However, chemical oxygen demand (COD) measurements showed that around 50% of the initial BAC was completely mineralized after 1 h of degradation at 50 mA/cm2, while the remaining electrooxidation of BAC resulted in the production of transformation products.

Insight into non-nucleoside triazole-based systems as viral polymerases inhibitors

Viruses have been recognized as the etiological agents responsible for many pathological conditions ranging from asymptomatic infections to serious diseases, even leading to death. For this reason, many efforts have been made to identify selective viral targets with the aim of developing efficient therapeutic strategies, devoid of drug-resistance issues. Considering their crucial role in the viral life cycle, polymerases are very attractive targets. Among the classes of compounds explored as viral polymerases inhibitors, here we present an overview of non-nucleoside triazole-based compounds identified in the last fifteen years. Furthermore, the structure-activity relationships (SAR) of the different chemical entities are described in order to highlight the key chemical features required for the development of effective antiviral agents.

Better design leads to better results - Importance of virological outcome design in clinical trials for antiviral treatment of coronavirus disease 2019.

Better design leads to better results - Importance of virological outcome design in clinical trials for antiviral treatment of coronavirus disease 2019.

A cellular and molecular biology-based update for ivermectin against COVID-19: is it effective or non-effective?

Despite community vaccination against coronavirus disease 2019 (COVID-19) and reduced mortality, there are still challenges in treatment options for the disease. Due to the continuous mutation of SARS-CoV-2 virus and the emergence of new strains, diversity in the use of existing antiviral drugs to combat the epidemic has become a crucial therapeutic chance. As a broad-spectrum antiparasitic and antiviral drug, ivermectin has traditionally been used to treat many types of disease, including DNA and RNA viral infections. Even so, based on currently available data, it is still controversial that ivermectin can be used as one of the effective antiviral agents to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or not. The aim of this study was to provide comprehensive information on ivermectin, including its safety and efficacy, as well as its adverse effects in the treatment of COVID-19.

The experience of re-infection among people who inject drugs successfully treated for hepatitis C

IntroductionHighly effective direct-acting antiviral (DAA) agents have changed the landscape of hepatitis C virus infection (HCV) treatment and have become more available to people who inject drugs (PWID) over the past several years. Although many achieve a sustained virologic response (SVR), a small proportion will become re-infected. This study examined experiences of re-infection among participants in Project HERO, a large multi-site treatment trial designed to test alternative treatment delivery models for DAAs. MethodsStudy staff conducted qualitative interviews with twenty-three HERO participants who experienced reinfection following successful treatment for HCV. Interviews focused on life circumstances and experiences with treatment/re-infection. We conducted a thematic analysis, followed by a narrative analysis. ResultsParticipants described challenging life circumstances. The initial experience of cure was joyful, leading participants to feel that they had escaped a defiled, stigmatized identity. Re-infection was very painful. Feelings of shame were common. Participants with fully developed narratives of re-infection described both a strong emotional response as well as a plan for avoiding re-infection during retreatment. Participants who lack such stories showed signs of hopelessness and apathy. ConclusionThough the promise of personal transformation through SVR may be motivating for patients, clinicians should be cautious about how they describe the “cure” when educating patients about HCV treatment. Patients should be encouraged to avoid stigmatizing, dichotomizing language of the self, including terms such as “dirty” and “clean.” In acknowledging the benefits of HCV cure, clinicians should emphasize that re-infection does not mean failed treatment; and that current treatment guidelines support retreatment of re-infected PWID.