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

Download Full-text

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

The Journal of Infection in Developing Countries ◽

10.3855/jidc.370 ◽

2007 ◽

Vol 1 (03) ◽

pp. 315-320 ◽

Cited By ~ 13

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.

Download Full-text

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

Natural Product Communications ◽

10.1177/1934578x1300800230 ◽

2013 ◽

Vol 8 (2) ◽

pp. 1934578X1300800 ◽

Cited By ~ 3

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.

Download Full-text

Antiviral and Cytotoxic Activity of Different Plant Parts of Banana (Musa spp.)

Viruses ◽

10.3390/v12050549 ◽

2020 ◽

Vol 12 (5) ◽

pp. 549

Author(s):

Sujogya Kumar Panda ◽

Ana Hortência Fonsêca Castro ◽

Ramin Saleh Jouneghani ◽

Pieter Leyssen ◽

Johan Neyts ◽

...

Keyword(s):

Antiviral Activity ◽

Cytotoxic Activity ◽

Yellow Fever ◽

Yellow Fever Virus ◽

Antiviral Drug ◽

Enterovirus 71 ◽

Fever Virus ◽

Therapeutic Window ◽

Viral Diseases ◽

Banana Plant

Chikungunya and yellow fever virus cause vector-borne viral diseases in humans. There is currently no specific antiviral drug for either of these diseases. Banana plants are used in traditional medicine for treating viral diseases such as measles and chickenpox. Therefore, we tested selected banana cultivars for their antiviral but also cytotoxic properties. Different parts such as leaf, pseudostem and corm, collected separately and extracted with four different solvents (hexane, acetone, ethanol, and water), were tested for in vitro antiviral activity against Chikungunya virus (CHIKV), enterovirus 71 (EV71), and yellow fever virus (YFV). Extracts prepared with acetone and ethanol from leaf parts of several cultivars exhibited strong (EC50 around 10 μg/mL) anti-CHIKV activity. Interestingly, none of the banana plant extracts (concentration 1–100 µg/mL) were active against EV71. Activity against YFV was restricted to two cultivars: Namwa Khom–Pseudostem–Ethanol (5.9 ± 5.4), Namwa Khom–Corm–Ethanol (0.79 ± 0.1) and Fougamou–Corm–Acetone (2.5 ± 1.5). In most cases, the cytotoxic activity of the extracts was generally 5- to 10-fold lower than the antiviral activity, suggesting a reasonable therapeutic window.

Download Full-text

Practical Synthesis of (−)-Carbocyclic Cytosine (Carbodine) and its In Vitro Antiviral Activity against Venezuelan Equine Encephalitis (VEE) Virus and Yellow Fever Virus

Antiviral Research ◽

10.1016/j.antiviral.2007.01.057 ◽

2007 ◽

Vol 74 (3) ◽

pp. A47-A47

Author(s):

J RAO ◽

J JULANDER ◽

R SIDWELL ◽

C CHU

Keyword(s):

Antiviral Activity ◽

Yellow Fever ◽

Yellow Fever Virus ◽

Fever Virus ◽

Venezuelan Equine Encephalitis ◽

Practical Synthesis

Download Full-text

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

Viruses ◽

10.3390/v12080802 ◽

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.

Download Full-text