Identification of a Neutralizing Epitope on TOSV Gn Glycoprotein

Emerging and re-emerging viral infections have been an important public health problem in recent years. We focused our attention on Toscana virus (TOSV), an emergent neurotropic negative-strand RNA virus of the Phenuiviridae family. The mechanisms of protection against phlebovirus natural infection are not known; however, it is supposed that a virus-neutralizing antibody response against viral glycoproteins would be useful to block the first stages of infection. By using an improved memory B cell immortalization method, we obtained a panel of human mAbs which reacted with TOSV antigens. We identified three epitopes of TOSV Gn glycoproteins by neutralizing mAbs using synthetic peptide arrays on membrane support (SPOT synthesis). These epitopes, separated in primary structure, might be exposed near one another as a conformational epitope in their native structure. In vivo studies were conducted to evaluate the humoral response elicited in mice immunized with the identified peptides. The results underlined the hypothesis that the first two peptides located in the NH2 terminus could form a conformational epitope, while the third, located near the transmembrane sequence in the carboxyl terminus, was necessary to strengthen neutralizing activity. Our results emphasize the importance of identifying neutralizing epitopes shared among the various phleboviruses, which could be exploited for the development of a potential epitope-based diagnostic assay or a polyvalent protective vaccine against different phleboviruses.

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Medicinal Plants and Bioactive Compounds for Diabetes Management: Important Advances for Drug Discovery

Current Pharmaceutical Design ◽

10.2174/1381612826666200928160357 ◽

2020 ◽

Vol 26 ◽

Author(s):

Kondeti Ramudu Shanmugam ◽

Bhasha Shanmugam ◽

Gangigunta Venkatasubbaiah ◽

Sahukari Ravi ◽

Kesireddy Sathyavelu Reddy

Keyword(s):

Herbal Medicine ◽

Medicinal Plants ◽

Bioactive Compounds ◽

Diabetes Management ◽

Therapeutic Potential ◽

Public Health Problem ◽

In Vivo Studies ◽

Major Public Health Problem

Background : Diabetes is a major public health problem in the world. It affects each and every part of the human body and also leads to organ failure. Hence, great progress made in the field of herbal medicine and diabetic research. Objectives: Our review will focus on the effect of bioactive compounds of medicinal plants which are used to treat diabetes in India and other countries. Methods: Information regarding diabetes, oxidative stress, medicinal plants and bioactive compounds were collected from different search engines like Science direct, Springer, Wiley online library, Taylor and francis, Bentham Science, Pubmed and Google scholar. Data was analyzed and summarized in the review. Results and Conclusion: Anti-diabetic drugs that are in use have many side effects on vital organs like heart, liver, kidney and brain. There is an urgent need for alternative medicine to treat diabetes and their disorders. In India and other countries herbal medicine was used to treat diabetes. Many herbal plants have antidiabetic effects. The plants like ginger, phyllanthus, curcumin, aswagandha, aloe, hibiscus and curcuma showed significant anti-hyperglycemic activities in experimental models and humans. The bioactive compounds like Allicin, azadirachtin, cajanin, curcumin, querceitin, gingerol possesses anti-diabetic, antioxidant and other pharmacological properties. This review focuses on the role of bioactive compounds of medicinal plants in prevention and management of diabetes. Conclusion: Moreover, our review suggests that bioactive compounds have the potential therapeutic potential against diabetes. However, further in vitro and in vivo studies are needed to validate these findings.

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Antimalarial drugs—are they beneficial in rheumatic and viral diseases?—considerations in COVID-19 pandemic

Clinical Rheumatology ◽

10.1007/s10067-021-05805-5 ◽

2021 ◽

Author(s):

Bogna Grygiel-Górniak

Keyword(s):

Connective Tissue ◽

Viral Infections ◽

Current Knowledge ◽

Inflammatory Diseases ◽

Antiviral Drugs ◽

In Vivo Studies ◽

Viral Diseases ◽

Cardiac Complications

AbstractThe majority of the medical fraternity is continuously involved in finding new therapeutic schemes, including antimalarial medications (AMDs), which can be useful in combating the 2019-nCoV: coronavirus disease (COVID-19). For many decades, AMDs have been widely used in the treatment of malaria and various other anti-inflammatory diseases, particularly to treat autoimmune disorders of the connective tissue. The review comprises in vitro and in vivo studies, original studies, clinical trials, and consensus reports for the analysis, which were available in medical databases (e.g., PubMed). This manuscript summarizes the current knowledge about chloroquine (CQ)/hydroxychloroquine (HCQ) and shows the difference between their use, activity, recommendation, doses, and adverse effects on two groups of patients: those with rheumatic and viral diseases (including COVID-19). In the case of connective tissue disorders, AMDs are prescribed for a prolonged duration in small doses, and their effect is observed after few weeks, whereas in the case of viral infections, they are prescribed in larger doses for a short duration to achieve a quick saturation effect. In rheumatic diseases, AMDs are well tolerated, and their side effects are rare. However, in some viral diseases, the effect of AMDs is questionable or not so noticeable as suggested during the initial prognosis. They are mainly used as an additive therapy to antiviral drugs, but recent studies have shown that AMDs can diminish the efficacy of some antiviral drugs and may cause respiratory, kidney, liver, and cardiac complications.

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In Vitro and In Vivo Activities of E5700 and ER-119884, Two Novel Orally Active Squalene Synthase Inhibitors, against Trypanosoma cruzi

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.7.2379-2387.2004 ◽

2004 ◽

Vol 48 (7) ◽

pp. 2379-2387 ◽

Cited By ~ 62

Author(s):

Julio A. Urbina ◽

Juan Luis Concepcion ◽

Aura Caldera ◽

Gilberto Payares ◽

Cristina Sanoja ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Public Health Problem ◽

Squalene Synthase ◽

Host Cells ◽

In Vivo Studies ◽

Inorganic Pyrophosphate ◽

Orally Active

ABSTRACT Chagas' disease is a serious public health problem in Latin America, and no treatment is available for the prevalent chronic stage. Its causative agent, Trypanosoma cruzi, requires specific endogenous sterols for survival, and we have recently demonstrated that squalene synthase (SQS) is a promising target for antiparasitic chemotherapy. E5700 and ER-119884 are quinuclidine-based inhibitors of mammalian SQS that are currently in development as cholesterol- and triglyceride-lowering agents in humans. These compounds were found to be potent noncompetitive or mixed-type inhibitors of T. cruzi SQS with K i values in the low nanomolar to subnanomolar range in the absence or presence of 20 μM inorganic pyrophosphate. The antiproliferative 50% inhibitory concentrations of the compounds against extracellular epimastigotes and intracellular amastigotes were ca. 10 nM and 0.4 to 1.6 nM, respectively, with no effects on host cells. When treated with these compounds at the MIC, all of the parasite's sterols disappeared from the parasite cells. In vivo studies indicated that E5700 was able to provide full protection against death and completely arrested the development of parasitemia when given at a concentration of 50 mg/kg of body weight/day for 30 days, while ER-119884 provided only partial protection. This is the first report of an orally active SQS inhibitor that is capable of providing complete protection against fulminant, acute Chagas' disease.

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Non-Toxic Virucidal Macromolecules Show High Efficacy Against Influenza Virus Ex Vivo and In Vivo

10.1101/2020.03.18.996678 ◽

2020 ◽

Author(s):

Ozgun Kocabiyik ◽

Valeria Cagno ◽

Paulo Jacob Silva ◽

Yong Zhu ◽

Laura Sedano ◽

...

Keyword(s):

Broad Spectrum ◽

Viral Infections ◽

Ex Vivo ◽

Public Health Problem ◽

Major Public Health Problem ◽

New Class ◽

Influenza Strain ◽

Low Toxicity

AbstractInfluenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6’sialyl-N-acetyllactosamine (6’SLN) or 3’SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..

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Mechanisms of Action of Ribavirin in Antiviral Therapies

Antiviral Chemistry and Chemotherapy ◽

10.1177/095632020101200501 ◽

2001 ◽

Vol 12 (5) ◽

pp. 261-272 ◽

Cited By ~ 80

Author(s):

Robert C Tam ◽

Johnson YN Lau ◽

Zhi Hong

Keyword(s):

Hepatitis C ◽

Viral Infections ◽

Rna Virus ◽

Lassa Fever ◽

Biological Properties ◽

Interferon Α ◽

Hepatitis C Infection ◽

Antiviral Activities ◽

Syncytial Virus

Although ribavirin was originally synthesized over 30 years ago and has been used to treat viral infections as monotherapy (respiratory syncytial virus and Lassa fever virus) or with interferon-α (IFN-α) as combination therapy (hepatitis C virus), the precise mechanism of its therapeutic activities remains controversial. In this review we focus on two main biological properties of ribavirin: its indirect and direct antiviral activities (with particular emphasis on its efficacy against chronic hepatitis C infection). Each property could individually or collectively account for its clinical efficacy against viral infections. First, with emphasis on the evidence for indirect activities of ribavirin, we will review the clinical observations that suggest that the immunomodulatory properties of ribavirin can in part account for its antiviral activities in vivo. We will then describe the mode of ribavirin's direct antiviral activities. These direct activities can be ascribed to several possible mechanisms, including the recently described activity as an RNA mutagen, a property that may be important in driving a rapidly mutating RNA virus over the threshold to ‘error catastrophe′.

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Application of Golden Nanoparticles against Streptococcus Mutans for Prevention of Caries Lesions

World Journal of Peri & Neonatology ◽

10.18502/wjpn.v3i2.6155 ◽

2021 ◽

Author(s):

Karim Daliri ◽

Neda Seifi-Shalamzari ◽

Maryam Saeida-Ardekani ◽

Sedigheh Ekraminasab ◽

Hossein Neamatzadeh

Keyword(s):

Streptococcus Mutans ◽

Antimicrobial Properties ◽

Public Health Problem ◽

In Vivo Studies ◽

Dilution Method ◽

Clinical Effects ◽

Baby Bottle ◽

Reduced Toxicity ◽

Critical Public Health

Background: Dental caries also known as baby bottle tooth decay, is a critical public health problem around the world for which Streptococcus mutans (S.mutans) has been introduced as the main infectious etiology. In the past two decades, nanotechnology has permitted the development of new materials with antimicrobial properties. The aim of this study was to compare the bactericidal and bacteriostatic effects of three golden nanoparticles (SP, NR, and CS) on S.mutans. Methods: To determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs), a liquid dilution method was applied. Results: All golden nanoparticles (GNPs) showed antimicrobial activity with no statistically significant differences (> 0.05) in MIC or MBC. Conclusion: Our findings revealed that the size and shape of the nanoparticles did not significantly affect the antimicrobial properties of the GNPs. This finding might be useful for achieving important clinical effects with reduced toxicity in the management of early childhood caries in future in vivo studies.

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Activity of tribendimidine and praziquantel combination therapy against the liver fluke Opisthorchis viverriniin vitro and in vivo

Journal of Helminthology ◽

10.1017/s0022149x12000387 ◽

2012 ◽

Vol 87 (2) ◽

pp. 252-256 ◽

Cited By ~ 11

Author(s):

J. Keiser ◽

R. Adelfio ◽

M. Vargas ◽

P. Odermatt ◽

S. Tesana

Keyword(s):

Worm Burden ◽

Liver Fluke ◽

Combination Index ◽

Public Health Problem ◽

Important Public Health Problem ◽

Important Public Health ◽

Single Drug ◽

Food Borne

AbstractOpisthorchiasis, caused by the liver fluke Opisthorchis viverrini, a food-borne trematode, is an important public health problem; however, only a single drug, praziquantel is available. We investigated tribendimidine–praziquantel combinations against O. viverriniin vitro and in vivo. The IC50 values of 0.16 μg/ml and 0.05 μg/ml were determined for praziquantel and tribendimidine, respectively, against adult O. viverriniin vitro. When O. viverrini was exposed to both drugs simultaneously (using a drug ratio based on the IC50 (1:3.2)) a synergistic effect was calculated (combination index (CI) at the IC50= 0.7). A similar result was observed when drug addition in vitro was spaced by the respective half-lives of the drugs (a CI of 0.78 at the IC50 for tribendimidine followed by praziquantel and a CI of 0.47 at the IC50 for praziquantel followed by tribendimidine). In vivo median-effect dose (ED50) values of 191 mg/kg and 147 mg/kg were calculated for praziquantel and tribendimidine, respectively. Low to moderate worm burden reductions (38–62%) were observed in O. viverrini infected hamsters when both drugs were administered simultaneously or on subsequent days, pointing to antagonistic effects in vivo. Further studies are necessary to understand the striking differences between the in vitro and in vivo observations using combinations of praziquantel and tribendimidine on O. viverrini.

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Molecular Mechanisms Involved in the Pathogenesis of Alphavirus-Induced Arthritis

BioMed Research International ◽

10.1155/2013/973516 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 46

Author(s):

Iranaia Assunção-Miranda ◽

Christine Cruz-Oliveira ◽

Andrea T. Da Poian

Keyword(s):

Animal Models ◽

Sindbis Virus ◽

Molecular Mechanisms ◽

Public Health Problem ◽

Target Cells ◽

Important Public Health Problem ◽

Muscle Tissues ◽

Mayaro Virus

Arthritogenic alphaviruses, including Ross River virus (RRV), Chikungunya virus (CHIKV), Sindbis virus (SINV), Mayaro virus (MAYV), O'nyong-nyong virus (ONNV), and Barmah Forest virus (BFV), cause incapacitating and long lasting articular disease/myalgia. Outbreaks of viral arthritis and the global distribution of these diseases point to the emergence of arthritogenic alphaviruses as an important public health problem. This review discusses the molecular mechanisms involved in alphavirus-induced arthritis, exploring the recent data obtained within vitrosystems andin vivostudies using animal models and samples from patients. The factors associated to the extension and persistence of symptoms are highlighted, focusing on (a) virus replication in target cells, and tissues, including macrophages and muscle cells; (b) the inflammatory and immune responses with recruitment and activation of macrophage, NK cells and T lymphocytes to the lesion focus and the increase of inflammatory mediators levels; and (c) the persistence of virus or viral products in joint and muscle tissues. We also discuss the importance of the establishment of novel animal models to test new molecular targets and to develop more efficient and selective drugs to treat these diseases.

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Potent germline-like monoclonal antibodies: Rapid identification of promising candidates for antibody-based antiviral therapy

Antibody Therapeutics ◽

10.1093/abt/tbab008 ◽

2021 ◽

Author(s):

Xiaoyi Zhu ◽

Fei Yu ◽

Yanling Wu ◽

Tianlei Ying

Keyword(s):

Monoclonal Antibodies ◽

Rational Design ◽

Large Scale ◽

Molecular Mechanisms ◽

Viral Infections ◽

Somatic Hypermutation ◽

Affinity Maturation ◽

Human Mabs

Abstract Recent years, fully human monoclonal antibodies (mAbs) are making up an increasing share of the pharmaceutical market. However, to improve affinity and efficacy of antibodies, many somatic hypermutation could be introduced during affinity maturation, which cause several issues including safety and efficacy and limit their application in clinic. Here, we propose a special class of human mAbs with limited level of somatic mutations, referred to as germline-like mAbs. Remarkably, germline-like mAbs could have high affinity and potent neutralizing activity in vitro and in various animal models, despite lacking of extensive affinity maturation. Furthermore, the germline nature of these mAbs implies that they exhibit lower immunogenicity and can be elicited relatively fast in vivo compared with highly somatically mutated antibodies. In this review, we summarize germline-like mAbs with strong therapeutic and protection activity against various viruses that caused large-scale outbreaks in the last decade, including influenza virus H7N9, Zika virus (ZIKV), Dengue virus (DENV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We also illustrate underlying molecular mechanisms of these germline-like antibodies against viral infections from the structural and genetic perspective, thus providing insight into further development as therapeutic agents for treatment of infectious diseases and implication for rational design of effective vaccines.

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Scolicidal and Apoptotic Activities of 5-hydroxy-1, 4-naphthoquinone as a Potent Agent against Echinococcus granulosus Protoscoleces

Pharmaceuticals ◽

10.3390/ph14070623 ◽

2021 ◽

Vol 14 (7) ◽

pp. 623

Author(s):

Masoud Moghadaszadeh ◽

Mehdi Khayyati ◽

Adel Spotin ◽

Roghayeh Norouzi ◽

Abdol Sattar Pagheh ◽

...

Keyword(s):

Echinococcus Granulosus ◽

Public Health Problem ◽

In Vivo Studies ◽

Cystic Hydatid Disease ◽

Liposomal System ◽

Physico Chemical ◽

Apoptotic Effect ◽

Apoptotic Activity

Cystic hydatid disease (CHD) is a zoonotic disease with different clinical stages caused by the larval stage of the cestode Echinococcus granulosus. It is important to highlight as a public health problem in various regions of the world. In the current study, the efficacy and apoptotic activity of the liposomal system containing juglone (5-hydroxy-1,4-naphthoquinone) were assessed against protoscoleces (PSCs) in vitro. To this aim, firstly, liposomal vesicles were prepared by the thin-film method. Their physico-chemical features were assessed using Zeta-Sizer and Scanning Electron Microscope (SEM). Subsequently, various concentrations (50, 100, 200, 400, and 800 μg/mL) of juglone nanoliposomes at different exposure times (15, 30, 60, and 120 min) were used against PSCs. Results showed that juglone nanoliposomes at all tested concentrations induced scolicidal effect, however, 800 μg/mL and 400 μg/mL of juglone nanoliposomes could reach 100% mortality in 60 and 120 min, respectively. Additionally, we found that caspase-3 mRNA expression was higher in PSCs treated with juglone nanoliposomes compared to control groups (p < 0.001). Therefore, juglone nanoliposomes are suggested to have a more potent apoptotic effect on PSCs. Generally, optimized doses of juglone nanoliposomes could display significant scolicidal effects. Moreover, further in vivo studies are required to evaluate the efficacy of this nanoliposome.

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