Antiviral and virucidal effects of curcumin on transmissible gastroenteritis virus in vitro

Emerging coronaviruses represent serious threats to human and animal health worldwide, and no approved therapeutics are currently available. Here, we used Transmissible gastroenteritis virus (TGEV) as the alpha-coronavirus model, and investigated the antiviral properties of curcumin against TGEV. Our results demonstrated that curcumin strongly inhibited TGEV proliferation and viral protein expression in a dose-dependent manner. We also observed that curcumin exhibited direct virucidal abilities in a dose-, temperature- and time-dependent manner. Furthermore, time-of-addition assays showed that curcumin mainly acted in the early phase of TGEV replication. Notably, in an adsorption assay, curcumin at 40 µM resulted in a reduction in viral titres of 3.55 log TCID50 ml–1, indicating that curcumin possesses excellent inhibitory effects on the adsorption of TGEV. Collectively, we demonstrate for the first time that curcumin has virucidal activity and virtual inhibition against TGEV, suggesting that curcumin might be a candidate drug for effective control of TGEV infection.

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The Influence of Bee Venom Melittin on the Functioning of the Immune System and the Contractile Activity of the Insect Heart—A Preliminary Study

Toxins ◽

10.3390/toxins11090494 ◽

2019 ◽

Vol 11 (9) ◽

pp. 494 ◽

Cited By ~ 5

Author(s):

Jan Lubawy ◽

Arkadiusz Urbański ◽

Lucyna Mrówczyńska ◽

Eliza Matuszewska ◽

Agata Światły-Błaszkiewicz ◽

...

Keyword(s):

Immune System ◽

Contractile Activity ◽

Model Organism ◽

Dependent Manner ◽

Physiological Studies ◽

Almost All ◽

First Time ◽

Dose Dependent ◽

Positive Effect

Melittin (MEL) is a basic polypeptide originally purified from honeybee venom. MEL exhibits a broad spectrum of biological activity. However, almost all studies on MEL activity have been carried out on vertebrate models or cell lines. Recently, due to cheap breeding and the possibility of extrapolating the results of the research to vertebrates, insects have been used for various bioassays and comparative physiological studies. For these reasons, it is valuable to examine the influence of melittin on insect physiology. Here, for the first time, we report the immunotropic and cardiotropic effects of melittin on the beetle Tenebrio molitor as a model insect. After melittin injection at 10−7 M and 10−3 M, the number of apoptotic cells in the haemolymph increased in a dose-dependent manner. The pro-apoptotic action of MEL was likely compensated by increasing the total number of haemocytes. However, the injection of MEL did not cause any changes in the percent of phagocytic haemocytes or in the phenoloxidase activity. In an in vitro bioassay with a semi-isolated Tenebrio heart, MEL induced a slight chronotropic-positive effect only at a higher concentration (10−4 M). Preliminary results indicated that melittin exerts pleiotropic effects on the functioning of the immune system and the endogenous contractile activity of the heart. Some of the induced responses in T. molitor resemble the reactions observed in vertebrate models. Therefore, the T. molitor beetle may be a convenient invertebrate model organism for comparative physiological studies and for the identification of new properties and mechanisms of action of melittin and related compounds.

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Identification of protease and ADP-ribose 1″-monophosphatase activities associated with transmissible gastroenteritis virus non-structural protein 3

Journal of General Virology ◽

10.1099/vir.0.81596-0 ◽

2006 ◽

Vol 87 (3) ◽

pp. 651-656 ◽

Cited By ~ 36

Author(s):

Ákos Putics ◽

Alexander E. Gorbalenya ◽

John Ziebuhr

Keyword(s):

Proximal Region ◽

Protein Sequencing ◽

Transmissible Gastroenteritis Virus ◽

Structural Protein ◽

Gastroenteritis Virus ◽

Viral Proteases ◽

C Terminus ◽

Processing Product ◽

Transmissible Gastroenteritis

The replicase polyproteins, pp1a and pp1ab, of porcine Transmissible gastroenteritis virus (TGEV) have been predicted to be cleaved by viral proteases into 16 non-structural proteins (nsp). Here, enzymic activities residing in the amino-proximal region of nsp3, the largest TGEV replicase processing product, were characterized. It was shown, by in vitro translation experiments and protein sequencing, that the papain-like protease 1, PL1pro, but not a mutant derivative containing a substitution of the presumed active-site nucleophile, Cys1093, cleaves the nsp2|nsp3 site at 879Gly|Gly880. By using an antiserum raised against the pp1a/pp1ab residues 526–713, the upstream processing product, nsp2, was identified as an 85 kDa protein in TGEV-infected cells. Furthermore, PL1pro was confirmed to be flanked at its C terminus by a domain (called X) that mediates ADP-ribose 1″-phosphatase activity. Expression and characterization of a range of bacterially expressed forms of this enzyme suggest that the active X domain comprises pp1a/pp1ab residues Asp1320–Ser1486.

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In vitro differentiation and pH sensitivity of field and cell culture-attentuated strains of transmissible gastroenteritis virus.

Infection and Immunity ◽

10.1128/iai.13.6.1642-1646.1976 ◽

1976 ◽

Vol 13 (6) ◽

pp. 1642-1646 ◽

Cited By ~ 15

Author(s):

R G Hess ◽

P A Bachmann

Keyword(s):

Cell Culture ◽

Ph Sensitivity ◽

Transmissible Gastroenteritis Virus ◽

In Vitro Differentiation ◽

Gastroenteritis Virus ◽

Transmissible Gastroenteritis

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Anti-Inflammatory Compounds from Vietnamese Piper bavinum

Journal of Chemistry ◽

10.1155/2020/1038636 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Viet Dung Hoang ◽

Phi Hung Nguyen ◽

Minh Thu Doan ◽

Manh Hung Tran ◽

Nhu Tuan Huynh ◽

...

Keyword(s):

Raw 264.7 Cells ◽

No Production ◽

Dependent Manner ◽

Protein Levels ◽

Chemical Structures ◽

Anti Inflammatory ◽

First Time ◽

Dose Dependent ◽

Potent Inhibitory Activity

This study reports the anti-inflammatory activity-guided fractionation of the aerial part of Piper bavinum C. CD. (Piperaceae) that led to the isolation of eight secondary metabolites (1–8). The chemical structures of 1–8 were established mainly by NMR and mass spectra. Compound 5 was isolated from P. bavinum for the first time. All the isolated compounds were evaluated against LPS-induced NO production in macrophage RAW 264.7 cells in vitro. Among them, compound 4 showed the most potent inhibitory activity against the LPS-induced NO production with an IC50 value of 5.2 μM followed by compound 5 that inhibited NO production with an IC50 value of 13.5 μM. In the protein levels, compound 4 suppressed LPS-induced COX-2 and iNOS expressions in a dose-dependent manner. The results suggested that P. bavinum and its constituents might exert anti-inflammatory effects.

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Recombinant dimeric small immunoproteins neutralize transmissible gastroenteritis virus infectivity efficiently in vitro and confer passive immunity in vivo

Journal of General Virology ◽

10.1099/0022-1317-88-3-1073 ◽

2007 ◽

Vol 88 (3) ◽

pp. 1073-1073

Author(s):

Marco Bestagno ◽

Isabel Sola ◽

Eliana Dallegno ◽

Patricia Sabella ◽

Monica Poggianella ◽

...

Keyword(s):

Passive Immunity ◽

Transmissible Gastroenteritis Virus ◽

Virus Infectivity ◽

Gastroenteritis Virus ◽

Transmissible Gastroenteritis

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Analysis of the Humoral Immune Response in Vitro to Transmissible Gastroenteritis Virus

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1986.tb21610.x ◽

1986 ◽

Vol 463 (1 Second Colloq) ◽

pp. 412-414 ◽

Cited By ~ 2

Author(s):

R. D. WESLEY ◽

I. V. WESLEY ◽

P. S. PAUL ◽

M. R. HALL ◽

R. D. WOODS

Keyword(s):

Immune Response ◽

Humoral Immune Response ◽

Transmissible Gastroenteritis Virus ◽

Humoral Immune ◽

Gastroenteritis Virus ◽

Transmissible Gastroenteritis ◽

Immune Response In Vitro

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Recombinant dimeric small immunoproteins neutralize transmissible gastroenteritis virus infectivity efficiently in vitro and confer passive immunity in vivo

Journal of General Virology ◽

10.1099/vir.0.82192-0 ◽

2007 ◽

Vol 88 (1) ◽

pp. 187-195 ◽

Cited By ~ 9

Author(s):

Marco Bestagno ◽

Isabel Sola ◽

Eliana Dallegno ◽

Patricia Sabella ◽

Monica Poggianella ◽

...

Keyword(s):

Passive Immunization ◽

Transmissible Gastroenteritis Virus ◽

Virus Infectivity ◽

Single Chain ◽

Variable Regions ◽

Chain Molecules ◽

Gastroenteritis Virus ◽

Transmissible Gastroenteritis

Small immunoproteins (SIPs) are single-chain molecules comprising the variable regions of an antibody assembled in a single polypeptide (scFv) and joined to the immunoglobulin heavy-chain dimerizing domain. To investigate the potential of these molecules to provide protection against enteric infections when supplied orally, SIPs were generated against Transmissible gastroenteritis virus (TGEV), a highly pathogenic porcine virus. Different variants of TGEV-specific SIPs were created, of ε and α isotypes, by exploiting the dimerizing domains εCH4 and αCH3 of human and swine origin. Transfected cells secreted these recombinant mini-antibodies efficiently, mainly as dimers stabilized covalently by inter-chain disulphide bridges. The specificity and functionality of the recombinant TGEV-specific SIPs were determined by in vitro binding, neutralization and infection-interference assays. The neutralization indices of the TGEV-specific SIPs were all very similar to that of the original TGEV-specific mAb, thus confirming that the immunological properties have been preserved in the recombinant SIPs. In vivo protection experiments on newborn piglets have, in addition, demonstrated a strong reduction of virus titre in infected tissues of animals treated orally with TGEV-specific SIPs. It has therefore been demonstrated that it is possible to confer passive immunization to newborn pigs by feeding them with recombinant SIPs.

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