scholarly journals Comparative Study on In Vitro Activities of Citral, Limonene and Essential Oils from Lippia citriodora and L. alba on Yellow Fever Virus

2013 ◽  
Vol 8 (2) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Luz Angela Gómez ◽  
Elena Stashenko ◽  
Raquel Elvira Ocazionez
Keyword(s):  
Antiviral Activity ◽  
Essential Oils ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
Lippia Citriodora ◽  
Virus Adsorption ◽  
Before And After ◽  
Ic50 Values

The aim of this study was to compare the antiviral activities in vitro of citral, limonene and essential oils (EOs) from Lippia citriodora and L. alba on the replication of yellow fever virus (YFV). Citral and EOs were active before and after virus adsorption on cells; IC50 values were between 4.3 and 25 μg/mL and SI ranged from 1.1 to 10.8. Results indicate that citral could contribute to the antiviral activity of the L. citriodora EO. Limonene was not active and seemed to play an insignificant role in the antiviral activity of the examined EOs.

scholarly journals In vitro evaluation of the antiviral activity of extracts from the lichen Parmelia perlata (L.) Ach. against three RNA viruses

2007 ◽  
Vol 1 (03) ◽  
pp. 315-320 ◽  
Author(s):  
Charles O. Esimone ◽  
Kenneth C. Ofokansi ◽  
Michael U. Adikwu ◽  
Emmanuel C. Ibezim ◽  
Dominic O. Abonyi ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Cell Lines ◽  
Yellow Fever ◽  
Cytopathic Effect ◽  
Yellow Fever Virus ◽  
Viral Envelope ◽  
Fever Virus ◽  
Polysaccharide Fraction ◽  
Crude Polysaccharide

Background: Substances extracted from lichens have previously been reported to possess antimicrobial activities against various groups of bacteria, fungi and viruses. Due to the high abundance of Parmelia perlata in the Eastern parts of Nigeria, we decided to explore whether it possesses antiviral activity against some common animal and human viruses. Methodology: The dried and powdered lichen was extracted with acetone, water and 4% (v/v) NaOH (to yield a crude polysaccharide fraction) using standard methods. The cytotoxicity of the extracts was investigated on HEP-2, Vero and L20 cell lines. The antiviral properties were determined against yellow fever, poliomyelitis and infectious bursal disease virus of chickens using the end-point cytopathic effect assay. Phytochemical evaluations of the extracts were also carried out. Results: Phytochemical tests showed the presence of flavonoids, saponins, tannins, glycosides, steroidal aglycone, carbohydrates and also the presence, in trace amounts, of some oligodynamic elements. Cytotoxicity tests revealed that while L20 was susceptible to the extracts at a concentration of 50 μg/ml, the extracts were generally toxic to the cell lines at concentrations above 500 μg/ml. The order of sensitivity of the cell lines was L20 > HEP-2 > Vero. The water and acetone extracts showed no activity against the viruses when tested at concentrations below the cytotoxic level while the crude polysaccharide fraction showed activity against yellow fever virus with an IC50 of 15 μg/ml. The time of addition of the test extracts to the infected cells did not have significant effect on cytopathic effect inhibition. Conclusions: The results showed that the crude polysaccharide fraction from Parmelia perlata possesses specific antiviral activity against yellow fever virus. It is postulated that a major mechanism of inhibition of yellow fever infection by the crude polysaccharide fraction of the lichen could be by attack on the viral envelope.

scholarly journals Screening for antiviral activity of two purified saponin fractions of Quillaja spp. against Yellow Fever Virus and Chikungunya Virus

2020 ◽  
Vol 8 (9) ◽  
pp. 205-214
Author(s):  
Eduardo Troian ◽  
Karoline Schallenberger ◽  
Francini Da Silva ◽  
Gabriela Dietrich ◽  
Fernando Ferreira Chiesa ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Yellow Fever ◽  
Chikungunya Virus ◽  
Yellow Fever Virus ◽  
Antiviral Drug ◽  
Fever Virus ◽  
African Green Monkey Kidney ◽  
Plaque Reduction Assay ◽  
Enveloped Virus

Yellow Fever Virus (YFV) and Chikungunya Virus (CHIV) are neglected reemerging pathogens that cause comorbidities worldwide. Since no antiviral drug is prescribed for those infections, there is a demand on researching compounds that inhibit viral replication. Saponins are amphiphilic compounds that already demonstrated in vitro activity against enveloped virus. Therefore, two purified saponin fractions from Quillaja spp. were evaluated regarding their antiviral potential against YFV and CHIKV. The cell line used in this study was VERO (African green monkey kidney cells) since it is permissive to the replication of both viruses. The antiviral activity of both saponins fractions was screened using the plaque reduction assay protocol. Although saponins did not inhibited YFV replication, they strongly inhibited CHIKV. To confirm the absence of antiviral activity of Quillaja saponins against YFV, the cytopathic effect inhibition assay was performed also. Further studies are required to determine the antiviral mechanisms involved in the CHIKV inhibition.

scholarly journals Yellow Fever Virus Down-Regulates mRNA Expression of SOCS1 in the Initial Phase of Infection in Human Cell Lines

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 802
Author(s):  
Michael B. Yakass ◽  
David Franco ◽  
Osbourne Quaye
Keyword(s):  
Mrna Expression ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Expression Patterns ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Interferon Β ◽  
Infected Cells ◽  
Insight Into

Flaviviruses are constantly evolving diverse immune evasion strategies, and the exploitation of the functions of suppressors of cytokine signalling (SOCS) and protein inhibitors of activated STATs (PIAS) to favour virus replication has been described for Dengue and Japanese encephalitis viruses but not for yellow fever virus (YFV), which is still of global importance despite the existence of an effective vaccine. Some mechanisms that YFV employs to evade host immune defence has been reported, but the expression patterns of SOCS and PIAS in infected cells is yet to be determined. Here, we show that SOCS1 is down-regulated early in YFV-infected HeLa and HEK 293T cells, while SOCS3 and SOCS5 are not significantly altered, and PIAS mRNA expression appears to follow a rise-dip pattern akin to circadian-controlled genes. We also demonstrate that YFV evades interferon-β application to produce comparable viral titres. This report provides initial insight into the in vitro expression dynamics of SOCS and PIAS upon YFV infection and a basis for further investigation into SOCS/PIAS expression and how these modulate the immune response in animal models.

scholarly journals Yellow fever virus is susceptible to sofosbuvir both in vitro and in vivo

2019 ◽  
Vol 13 (1) ◽  
pp. e0007072 ◽  
Author(s):  
Caroline S. de Freitas ◽  
Luiza M. Higa ◽  
Carolina Q. Sacramento ◽  
André C. Ferreira ◽  
Patrícia A. Reis ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus

CULTURE OF YELLOW-FEVER VIRUS IN VITRO

The Lancet ◽  
1940 ◽  
Vol 236 (6102) ◽  
pp. 163-164 ◽  
Author(s):  
G.M. Findlay ◽  
F.O. Maccallum
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus

Thiosemicarbazones and Phthalyl-Thiazoles compounds exert antiviral activity against yellow fever virus and Saint Louis encephalitis virus

2017 ◽  
Vol 87 ◽  
pp. 381-387 ◽  
Author(s):  
Carolina Colombelli Pacca ◽  
Rafael Elias Marques ◽  
José Wanderlan P. Espindola ◽  
Gevânio B.O.Oliveira Filho ◽  
Ana Cristina Lima Leite ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Encephalitis Virus ◽  
Fever Virus ◽  
Saint Louis ◽  
Saint Louis Encephalitis

scholarly journals High Fidelity of Yellow Fever Virus RNA Polymerase

2004 ◽  
Vol 78 (2) ◽  
pp. 1032-1038 ◽  
Author(s):  
Konstantin V. Pugachev ◽  
Farshad Guirakhoo ◽  
Simeon W. Ocran ◽  
Fred Mitchell ◽  
Megan Parsons ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Rna Polymerase ◽  
Yellow Fever ◽  
Error Rate ◽  
Yellow Fever Virus ◽  
Protein A ◽  
Fever Virus ◽  
Genome Replication ◽  
Virus Rna

ABSTRACT Three consecutive plaque purifications of four chimeric yellow fever virus-dengue virus (ChimeriVax-DEN) vaccine candidates against dengue virus types 1 to 4 were performed. The genome of each candidate was sequenced by the consensus approach after plaque purification and additional passages in cell culture. Our data suggest that the nucleotide sequence error rate for SP6 RNA polymerase used in the in vitro transcription step to initiate virus replication was as high as 1.34 × 10−4 per copied nucleotide and that the error rate of the yellow fever virus RNA polymerase employed by the chimeras for genome replication in infected cells was as low as 1.9 × 10−7 to 2.3 × 10−7. Clustering of beneficial mutations that accumulated after multiple virus passages suggests that the N-terminal part of the prM protein, a specific site in the middle of the E protein, and the NS4B protein may be essential for nucleocapsid-envelope interaction during flavivirus assembly.

scholarly journals THE ADAPTATION OF UNMODIFIED STRAINS OF YELLOW FEVER VIRUS TO CULTIVATION IN VITRO

1937 ◽  
Vol 65 (6) ◽  
pp. 801-808 ◽  
Author(s):  
Hugh H. Smith ◽  
Max Theiler
Keyword(s):  
Brain Tissue ◽  
Yellow Fever ◽  
Mouse Embryo ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
In Vitro Cultivation ◽  
Virus Content ◽  
Cultivation In Vitro ◽  
Embryo Brain

1. In a search for suitable tissues for the cultivation of yellow fever virus in vitro, mouse embryos were inoculated with this virus in utero. A titration for virus content of the various organs of the embryos indicated that the virus was present in the brain in greatest concentration. 2. Unmodified strains of yellow fever virus were readily adapted to cultivation in vitro in a medium consisting of minced mouse embryo brain tissue and Tyrode solution containing 10 per cent normal monkey serum. 3. After a continued cultivation in mouse embryo brain tissue cultures for twenty to twenty-five subcultures, these strains were readily adapted to cultivation in whole mouse embryo tissue medium. 4. There is evidence to indicate that a prolonged cultivation of the virus in mouse embryo brain medium increases its neurotropic properties. 5. Attempts to employ monkey tissues for in vitro cultivation of yellow fever virus gave entirely negative results.

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