scholarly journals Antiviral Effects of an Iminosugar Derivative on Flavivirus Infections

2002 ◽  
Vol 76 (8) ◽  
pp. 3596-3604 ◽  
Author(s):  
Shu-Fen Wu ◽  
Chyan-Jang Lee ◽  
Ching-Len Liao ◽  
Raymond A. Dwek ◽  
Nicole Zitzmann ◽  
...  
Keyword(s):  
Oral Delivery ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Lethal Challenge ◽  
Reverse Transcription Pcr ◽  
Glucosidase Inhibitors ◽  
Virus Serotype ◽  
Viral Glycoproteins ◽  
Flavivirus Infection

ABSTRACT Endoplasmic reticulum (ER) α-glucosidase inhibitors, which block the trimming step of N-linked glycosylation, have been shown to eliminate the production of several ER-budding viruses. Here we investigated the effects of one such inhibitor, N-nonyl-deoxynojirimycin (NN-DNJ), a 9-carbon alkyl iminosugar derivative, on infection by Japanese encephalitis virus (JEV) and dengue virus serotype 2 (DEN-2). In the presence of NN-DNJ, JEV and DEN-2 infections were suppressed in a dose-dependent manner. This inhibitory effect appeared to influence DEN-2 infection more than JEV infection, since lower concentrations of NN-DNJ substantially blocked DEN-2 replication. Secretion of the flaviviral glycoproteins E and NS1 was greatly reduced, and levels of DEN-2 viral RNA replication measured by fluorogenic reverse transcription-PCR were also decreased, by NN-DNJ. Notably, the viral glycoproteins, prM, E, and NS1 were found to associate transiently with the ER chaperone calnexin, and this interaction was affected by NN-DNJ, suggesting a potential role of calnexin in the folding of flaviviral glycoproteins. Additionally, in a mouse model of lethal challenge by JEV infection, oral delivery of NN-DNJ reduced the mortality rate. These findings show that NN-DNJ has an antiviral effect on flavivirus infection, likely through interference with virus replication at the posttranslational modification level, occurring mainly in the ER.

scholarly journals Internal Ribosome Entry Site Dramatically Reduces Transgene Expression in Hematopoietic Cells in a Position-Dependent Manner

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 920 ◽  
Author(s):  
Qingyun Zheng ◽  
Xueyan Zhang ◽  
Hua Yang ◽  
Jinyan Xie ◽  
Yilin Xie ◽  
...  
Keyword(s):  
Internal Ribosome Entry Site ◽  
Transgene Expression ◽  
Hematopoietic Cells ◽  
Inhibitory Effect ◽  
Encephalomyocarditis Virus ◽  
Transduction Efficiency ◽  
Dependent Manner ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Virus Serotype

Bicistronic transgene expression mediated by internal ribosome entry site (IRES) elements has been widely used. It co-expresses heterologous transgene products from a message RNA driven by a single promoter. Hematologic gene delivery is a promising treatment for both inherited and acquired diseases. A combined strategy was recently documented for potential genome editing in hematopoietic cells. A transduction efficiency exceeding ~90% can be achieved by capsid-optimized recombinant adeno-associated virus serotype 6 (rAAV6) vectors. In this study, to deliver an encephalomyocarditis virus (EMCV) IRES-containing rAAV6 genome into hematopoietic cells, we observed that EMCV IRES almost completely shut down the transgene expression during the process of mRNA–protein transition. In addition, position-dependent behavior was observed, in which only the EMCV IRES element located between a promoter and the transgenes had an inhibitory effect. Although further studies are warranted to evaluate the involvement of cellular translation machinery, our results propose the use of specific IRES elements or an alternative strategy, such as the 2A system, to achieve bicistronic transgene expression in hematopoietic cells.

Inhibitory Effect of Oral Thin Films (OTFs) Containing Xylitol Against Streptococcus mutans

2022 ◽  
Vol 16 (1) ◽  
pp. 124
Author(s):  
Elizabeth Yi Ern Teng ◽  
Hee Xixian ◽  
Muhamad Fareez Ismail
Keyword(s):  
Thin Films ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Oral Delivery ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Dependent Manner ◽  
Disintegration Time ◽  
Poor Patient Compliance ◽  
Significant Difference

Dental Caries is a chronic disease affecting half of the global population, causing pain and discomfort due to progressive damage to the teeth. Whilst xylitol has been studied for its effect on dental caries prevention, current practices present few limitations for its successful oral delivery, including short residence time in the mouth and poor patient compliance. Recently, oral thin films (OTFs) emerged as an alternative to delivering xylitol in the oral cavity. This research aims to develop novel OTFs containing xylitol with extended-release properties (as determined by the disintegration time) and to investigate its effect on a cariogenic bacterial strain, Streptococcus mutans. The minimum inhibitory concentration (MIC) of xylitol was determined. Employing the microdilution broth method, the antibacterial activity of the oral thin films containing xylitol for oral S. mutans was performed with simulated salivary fluid, incubated at 1, 4, and 10 h. The MIC of xylitol was found at 10%. Meanwhile, there was no significant difference in the inhibition of S. mutans (p > 0.05) between the control, OTFs (10 h), and xylitol-OTF (1 h), with the latter, demonstrated only 16.58% inhibition. Interestingly, when compared to xylitol-OTF (1 h), xylitol-OTF showed significant inhibition (p < 0.05) to S. mutans after four h (+53.24 %) and almost a complete inhibition after ten h (-92.58 %). These results suggest that the OTFs demonstrated a gradual release of xylitol and inhibited oral biofilm formation by decreasing the growth of S. mutans in a time-dependent manner. Most importantly, the study indicated the successful development of a novel xylitol-OTF with potential as an oral health biotherapeutic agent.

scholarly journals Antiviral effect of α-glucosidase inhibitors on viral morphogenesis and binding properties of hepatitis C virus-like particles

2006 ◽  
Vol 87 (4) ◽  
pp. 861-871 ◽  
Author(s):  
Cynthia Chapel ◽  
Céline Garcia ◽  
Philippe Roingeard ◽  
Nicole Zitzmann ◽  
Jean Dubuisson ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Effect ◽  
Health Concern ◽  
Structural Protein ◽  
Binding Properties ◽  
Virus Like Particles ◽  
Glucosidase Inhibitors ◽  
Viral Glycoproteins ◽  
Viral Morphogenesis

Hepatitis C virus (HCV) infections are a major public-health concern. New antiviral drugs are needed urgently to complement and improve the efficacy of current chemotherapies. The morphogenesis of HCV represents an interesting, and still unexploited, novel molecular target. α-Glucosidase inhibitors derived from the glucose analogue deoxynojirimycin (DNJ) inhibit viral morphogenesis in cellulo via perturbation of the N-glycosylation pathway and hence the misfolding of viral glycoproteins that depend on certain N-glycans for correct folding. Due to the heavy N-glycosylation of HCV glycoproteins, it was hypothesized that such inhibitors would also affect HCV morphogenesis. To study the effect of α-glucosidase inhibitors on viral morphogenesis and binding properties, HCV virus-like particles (VLPs) were produced by using baculovirus loaded with HCV structural-protein genes. Here, it is demonstrated that, in the presence of these α-glucosidase inhibitors, viral glycoproteins synthesized and retained in the endoplasmic reticulum (i) contain unprocessed, triglucosylated N-glycans, (ii) are impaired in their interaction with calnexin and (iii) are at least partially misfolded. Moreover, it is shown that, although the production of VLPs is not affected by α-glucosidase inhibitors, these VLPs contain unprocessed, triglucosylated N-glycans and potentially misfolded glycoproteins. Finally, it is demonstrated that VLPs produced in the presence of α-glucosidase inhibitors have impaired binding properties to hepatoma cells. The inhibitors of morphogenesis studied here target steps of the HCV viral cycle that may prevent or delay viral resistance. These α-glucosidase inhibitors may prove to be useful molecules to fight HCV infection in combination protocols.

scholarly journals Adenovirus vectored IFN-α protects mice from lethal challenge of Chikungunya virus infection

2020 ◽  
Vol 14 (12) ◽  
pp. e0008910
Author(s):  
Huixin Chen ◽  
Nyo Min ◽  
Luyao Ma ◽  
Chee-Keng Mok ◽  
Justin Jang Hann Chu
Keyword(s):  
Single Dose ◽  
Chikungunya Virus ◽  
Lethal Dose ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Chikv Infection ◽  
Lethal Challenge ◽  
Virus Challenge ◽  
Multiple Organs

Chikungunya virus (CHIKV) is a mosquito-borne pathogen that is responsible for numerous large and geographical epidemics, causing millions of cases. However, there is no vaccine or therapeutics against CHIKV infection available. Interferon-alpha (IFN-α) has been shown to produce potent antiviral responses during viral infection. Herein we demonstrated the use of an adenovirus-vectored expressed mouse IFN-α (mDEF201) as a prophylactic and therapeutic treatment against CHIKV in vivo. 6-day-old BALB/c mice were pre- or post-treated intranasally with single dose of mDEF201 at 5 x 106 PFU per mouse and challenged with lethal dose of CHIKV. Complete survival protection was observed in mice upon a single dose of mDEF201 administration 1 days prior to virus challenge. Viral load in the serum and multiple organs were significantly reduced upon mDEF201 administration in a dose dependent manner as compare with adenovirus 5 vector placebo set. Histological analysis of the mice tissue revealed that mDEF201 could significantly reduce the tissue morphological abnormities, mainly infiltration of immune cells and muscle fibre necrosis caused by CHIKV infection. In addition, administration of mDEF201 at 6 hours post CHIKV challenge also showed promising inhibitory effect against viral replication and dissemination. In conclusion, single-dose of intranasal administration with mDEF201 as a prophylactic or therapeutic agent within 6 hours post CHIKV infection is highly protective against a lethal challenge of CHIKV in the murine model.

Synthesis and Assessment of Novel Anti-chlamydial Benzylidene Acylhydrazides Derivatives

2018 ◽  
Vol 15 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Xiaofeng Bao ◽  
Ying Xue ◽  
Chao Xia ◽  
Yin Lu ◽  
Ningjing Yang ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dependent Manner ◽  
Iron Starvation ◽  
Hydrochloride Salt ◽  
Obligate Intracellular ◽  
Biphasic Life Cycle ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Dose Dependent ◽  
Better Than

Background: Chlamydiae, characterized by a unique biphasic life cycle, are a group of Gram-negative obligate intracellular bacterial pathogens responsible for diseases in a range of hosts including humans. Benzylidene acylhydrazide CF0001 could inhibit chlamydiae independent of iron starvation and T3SS inhibition. This finding promoted us to design and synthesize more benzylidene acylhydrazides to find novel anti-chlamydial agents. Methods: The carboxylic acids 1a-1d were coupled with Boc-hydrazide inpresence of EDCI and DMAP to obtain the intermediate 2a-2d in 60-62% yields. N-Boc deprotections were performed to obtain hydrazide hydrochloride salt 3a-3d. Nextly, the hydrazides were subjected to condensation with aldehydes to obtain benzylidene acylhydrazides 4a-4g in 30-52% yields in two steps. Results: Compound 4d exhibited best inhibitory effect on the formation and growth of chlamydial inclusions. The IC50 value of compound 4d for infectious progenies was 3.55 µM, better than 7.30 µM of CF0001. Conclusion: To find novel anti-chlamydial agents, we have designed and synthesized benzylidene acylhydrazides 4a-4g. Compounds 4a, 4d, 4g showed inhibitory activity on C. muridarum with the IC50 values from 3.55-12 µM. The 3,5-dibromo-4-hydroxyl substitutes on ring B are critical to keep their anti-chlamydial activity. Compound 4d inhibited C. muridarum in a dose-dependent manner without apparent cytotoxicity.

scholarly journals Antiviral Activity of the PropylamylatinTM Formula against the Novel Coronavirus SARS-CoV-2 In Vitro Using Direct Injection and Gas Assays in Virus Suspensions

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 415
Author(s):  
Ashley N. Brown ◽  
Gary Strobel ◽  
Kaley C. Hanrahan ◽  
Joe Sears
Keyword(s):  
Propionic Acid ◽  
Infectious Virus ◽  
Direct Injection ◽  
Plaque Assay ◽  
Antiviral Effect ◽  
Dependent Manner ◽  
Global Public Health ◽  
Novel Coronavirus ◽  
The Individual

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of novel coronavirus disease 2019 (COVID-19), has become a severe threat to global public health. There are currently no antiviral therapies approved for the treatment or prevention of mild to moderate COVID-19 as remdesivir is only approved for severe COVID-19 cases. Here, we evaluated the antiviral potential of a Propylamylatin formula, which is a mixture of propionic acid and isoamyl hexanoates. The Propylamylatin formula was investigated in gaseous and liquid phases against 1 mL viral suspensions containing 105 PFU of SARS-CoV-2. Viral suspensions were sampled at various times post-exposure and infectious virus was quantified by plaque assay on Vero E6 cells. Propylamylatin formula vapors were effective at inactivating infectious SARS-CoV-2 to undetectable levels at room temperature and body temperature, but the decline in virus was substantially faster at the higher temperature (15 min versus 24 h). The direct injection of liquid Propylamylatin formula into viral suspensions also completely inactivated SARS-CoV-2 and the rapidity of inactivation occurred in an exposure dependent manner. The overall volume that resulted in 90% viral inactivation over the course of the direct injection experiment (EC90) was 4.28 µls. Further investigation revealed that the majority of the antiviral effect was attributed to the propionic acid which yielded an overall EC90 value of 11.50 µls whereas the isoamyl hexanoates provided at most a 10-fold reduction in infectious virus. The combination of propionic acid and isoamyl hexanoates was much more potent than the individual components alone, suggesting synergy between these components. These findings illustrate the therapeutic promise of the Propylamylatin formula as a potential treatment strategy for COVID-19 and future studies are warranted.

scholarly journals Brassinolide Enhances the Level of Brassinosteroids, Protein, Pigments, and Monosaccharides in Wolffia arrhiza Treated with Brassinazole

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1311
Author(s):  
Magdalena Chmur ◽  
Andrzej Bajguz
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Plant Growth And Development ◽  
Concentration Dependent Manner ◽  
Spectrophotometric Methods ◽  
Synthetic Inhibitor ◽  
Wolffia Arrhiza ◽  
First Time

Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz.

scholarly journals Review on the Regional Effects of Gastrointestinal Luminal Stimulation on Appetite and Energy Intake: (Pre)clinical Observations

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1601
Author(s):  
Jennifer Wilbrink ◽  
Gwen Masclee ◽  
Tim Klaassen ◽  
Mark van Avesaat ◽  
Daniel Keszthelyi ◽  
...  
Keyword(s):  
Energy Intake ◽  
Oral Delivery ◽  
Regional Differences ◽  
Management Strategies ◽  
Inhibitory Effect ◽  
Current Evidence ◽  
Ileal Brake ◽  
Regional Effects ◽  
Clinical Observations ◽  
Intestinal Delivery

Macronutrients in the gastrointestinal (GI) lumen are able to activate “intestinal brakes”, feedback mechanisms on proximal GI motility and secretion including appetite and energy intake. In this review, we provide a detailed overview of the current evidence with respect to four questions: (1) are regional differences (duodenum, jejunum, ileum) present in the intestinal luminal nutrient modulation of appetite and energy intake? (2) is this “intestinal brake” effect macronutrient specific? (3) is this “intestinal brake” effect maintained during repetitive activation? (4) can the “intestinal brake” effect be activated via non-caloric tastants? Recent evidence indicates that: (1) regional differences exist in the intestinal modulation of appetite and energy intake with a proximal to distal gradient for inhibition of energy intake: ileum and jejunum > duodenum at low but not at high caloric infusion rates. (2) the “intestinal brake” effect on appetite and energy appears not to be macronutrient specific. At equi-caloric amounts, the inhibition on energy intake and appetite is in the same range for fat, protein and carbohydrate. (3) data on repetitive ileal brake activation are scarce because of the need for prolonged intestinal intubation. During repetitive activation of the ileal brake for up to 4 days, no adaptation was observed but overall the inhibitory effect on energy intake was small. (4) the concept of influencing energy intake by intra-intestinal delivery of non-caloric tastants is intriguing. Among tastants, the bitter compounds appear to be more effective in influencing energy intake. Energy intake decreases modestly after post-oral delivery of bitter tastants or a combination of tastants (bitter, sweet and umami). Intestinal brake activation provides an interesting concept for preventive and therapeutic approaches in weight management strategies.

scholarly journals Pyrvinium pamoate inhibits cell proliferation through ROS-mediated AKT-dependent signaling pathway in colorectal cancer

2021 ◽  
Vol 38 (2) ◽  
Author(s):  
Wenqian Zheng ◽  
Jinhui Hu ◽  
Yiming Lv ◽  
Bingjun Bai ◽  
Lina Shan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Epithelial To Mesenchymal Transition ◽  
Flow Cytometric Analysis ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Mesenchymal Transition ◽  
Dependent Signaling Pathway ◽  
Pyrvinium Pamoate

AbstractThe use of the anthelmintic drug pyrvinium pamoate (PP) in cancer therapy has been extensively investigated in the last decade. PP has been shown to have an inhibitory effect in colorectal cancer (CRC), but the underlying mechanism remains elusive. We aimed to investigate the antitumor activity and mechanisms of PP in CRC. In the present study, we used CCK-8 assays, colony formation assays, and western blotting to reveal that PP effectively suppressed CRC cell proliferation and the AKT-dependent signaling pathway in a concentration-dependent and time-dependent manner. Flow cytometric analysis and fluorescence microscopy demonstrated that PP increased intracellular reactive oxygen species (ROS) accumulation. We found that the inhibitory effect of PP on cell proliferation and AKT protein expression induced by PP could be partially reversed by N-acetyl-l-cysteine (NAC), an ROS scavenger. In addition, the results also demonstrated that PP inhibited cell migration by modulating epithelial-to-mesenchymal transition (EMT)-related proteins, including E-cadherin and vimentin. In conclusion, our data suggested that PP effectively inhibited cell proliferation through the ROS-mediated AKT-dependent signaling pathway in CRC, further providing evidence for the use of PP as an antitumor agent.

scholarly journals Petasin and isopetasin reduce CGRP release from trigeminal afferents indicating an inhibitory effect on TRPA1 and TRPV1 receptor channels

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Johanna Kleeberg-Hartmann ◽  
Birgit Vogler ◽  
Karl Messlinger
Keyword(s):  
Inhibitory Effect ◽  
Transient Receptor Potential Channels ◽  
Mustard Oil ◽  
Root Extract ◽  
Dependent Manner ◽  
Trpv1 Receptor ◽  
Cgrp Release ◽  
Ganglion Neurons ◽  
Sites Of Action ◽  
The Impact

Abstract Background Butterbur root extract with its active ingredients petasin and isopetasin has been used in the prophylactic treatment of migraine for years, while its sites of action are not completely clear. Calcitonin gene-related peptide (CGRP) is known as a biomarker and promoting factor of migraine. We set out to investigate the impact of petasins on the CGRP release from trigeminal afferents induced by activation of the calcium conducting transient receptor potential channels (TRPs) of the subtypes TRPA1 and TRPV1. Methods We used well-established in vitro preparations, the hemisected rodent skull and dissected trigeminal ganglia, to examine the CGRP release from rat and mouse cranial dura mater and trigeminal ganglion neurons, respectively, after pre-incubation with petasin and isopetasin. Mustard oil and capsaicin were used to stimulate TRPA1 and TRPV1 receptor channels. CGRP concentrations were measured with a CGRP enzyme immunoassay. Results Pre-incubation with either petasin or isopetasin reduced mustard oil- and capsaicin-evoked CGRP release compared to vehicle in an approximately dose-dependent manner. These results were validated by additional experiments with mice expressing functionally deleted TRPA1 or TRPV1 receptor channels. Conclusions Earlier findings of TRPA1 receptor channels being involved in the site of action of petasin and isopetasin are confirmed. Furthermore, we suggest an important inhibitory effect on TRPV1 receptor channels and assume a cooperative action between the two TRP receptors. These mechanisms may contribute to the migraine prophylactic effect of petasins.

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