Limits...
Virocidal activity of Egyptian scorpion venoms against hepatitis C virus.

El-Bitar AM, Sarhan MM, Aoki C, Takahara Y, Komoto M, Deng L, Moustafa MA, Hotta H - Virol. J. (2015)

Bottom Line: Development of well-tolerated regimens with high cure rates and fewer side effects is still much needed.S. maurus palmatus venom is considered as a good natural source for characterization and development of novel anti-HCV agents targeting the entry step.To our knowledge, this is the first report describing antiviral activities of Egyptian scorpion venoms against HCV, and may open a new approach towards discovering antiviral compounds derived from scorpion venoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, Faculty of Science, Al-Azhar University, Assiut, Egypt. sci.elbitar@gmail.com.

ABSTRACT

Background: Hepatitis C virus (HCV) is a major global health problem, causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Development of well-tolerated regimens with high cure rates and fewer side effects is still much needed. Recently, natural antimicrobial peptides (AMPs) are attracting more attention as biological compounds and can be a good template to develop therapeutic agents, including antiviral agents against a variety of viruses. Various AMPs have been characterized from the venom of different venomous animals including scorpions.

Methods: The possible antiviral activities of crude venoms obtained from five Egyptian scorpion species (Leiurus quinquestriatus, Androctonus amoreuxi, A. australis, A. bicolor and Scorpio maurus palmatus) were evaluated by a cell culture method using Huh7.5 cells and the J6/JFH1-P47 strain of HCV. Time-of-addition experiments and inactivation of enzymatic activities of the venoms were carried out to determine the characteristics of the anti-HCV activities.

Results: S. maurus palmatus and A. australis venoms showed anti-HCV activities, with 50% inhibitory concentrations (IC₅₀) being 6.3 ± 1.6 and 88.3 ± 5.8 μg/ml, respectively. S. maurus palmatus venom (30 μg/ml) impaired HCV infectivity in culture medium, but not inside the cells, through virocidal effect. The anti-HCV activity of this venom was not inhibited by a metalloprotease inhibitor or heating at 60°C. The antiviral activity was directed preferentially against HCV.

Conclusions: S. maurus palmatus venom is considered as a good natural source for characterization and development of novel anti-HCV agents targeting the entry step. To our knowledge, this is the first report describing antiviral activities of Egyptian scorpion venoms against HCV, and may open a new approach towards discovering antiviral compounds derived from scorpion venoms.

Show MeSH

Related in: MedlinePlus

Effects of neutralization of the proteinase activities of the virocidal effects ofS. maurus palmatusvenom against HCV.S. maurus palmatus venom (30 μg/ml) was treated with a metalloproteinase inhibitor (1, 10-phenan-throline; 5 mM) at 4°C or 60°C for 20 min. The treated venom was mixed with HCV for 2 hr at 37°C and the mixture was inoculated to Huh7.5 cells for 2 hr at 37°C. The cells were cultivated in the absence of the venom for one day. The culture supernatants were titrated for virus infectivity (A) and the cells were subjected to immunoblot analysis using monoclonal antibody against the HCV NS3 protein (B). GAPDH served as an internal control to verify equal amounts of sample loading. Data represent means ± SEM of the data obtained from two independent experiments. 1,10 Ph., 1,10-phenanthroline; §, below the detection limit.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4374190&req=5

Fig3: Effects of neutralization of the proteinase activities of the virocidal effects ofS. maurus palmatusvenom against HCV.S. maurus palmatus venom (30 μg/ml) was treated with a metalloproteinase inhibitor (1, 10-phenan-throline; 5 mM) at 4°C or 60°C for 20 min. The treated venom was mixed with HCV for 2 hr at 37°C and the mixture was inoculated to Huh7.5 cells for 2 hr at 37°C. The cells were cultivated in the absence of the venom for one day. The culture supernatants were titrated for virus infectivity (A) and the cells were subjected to immunoblot analysis using monoclonal antibody against the HCV NS3 protein (B). GAPDH served as an internal control to verify equal amounts of sample loading. Data represent means ± SEM of the data obtained from two independent experiments. 1,10 Ph., 1,10-phenanthroline; §, below the detection limit.

Mentions: In order to investigate whether anti-HCV activity of S. maurus palmatus venom involves an enzymatic activity, we treated the venom (30 μg/ml) with heating at 60°C for 20 min or a metalloproteinase inhibitor, 1, 10-phenan-throline (5 mM) to inactivate them, as reported by other investigators [31-34]. The treated venom was added to HCV and incubated for 2 hr at 37°C. Then, the virus/venom mixture was inoculated to Huh7.5 cells and virus replication was analyzed. The results obtained revealed that the treated venom, either treated with heating at 60°C or the metalloproteinase inhibitor, or both at the same time, still markedly suppressed production of HCV infectious particles in the culture to the same extent compared to the untreated control (Figure 3A). Consistent with this observation, accumulation of intracellular HCV NS3 protein was also inhibited (Figure 3B).Figure 3


Virocidal activity of Egyptian scorpion venoms against hepatitis C virus.

El-Bitar AM, Sarhan MM, Aoki C, Takahara Y, Komoto M, Deng L, Moustafa MA, Hotta H - Virol. J. (2015)

Effects of neutralization of the proteinase activities of the virocidal effects ofS. maurus palmatusvenom against HCV.S. maurus palmatus venom (30 μg/ml) was treated with a metalloproteinase inhibitor (1, 10-phenan-throline; 5 mM) at 4°C or 60°C for 20 min. The treated venom was mixed with HCV for 2 hr at 37°C and the mixture was inoculated to Huh7.5 cells for 2 hr at 37°C. The cells were cultivated in the absence of the venom for one day. The culture supernatants were titrated for virus infectivity (A) and the cells were subjected to immunoblot analysis using monoclonal antibody against the HCV NS3 protein (B). GAPDH served as an internal control to verify equal amounts of sample loading. Data represent means ± SEM of the data obtained from two independent experiments. 1,10 Ph., 1,10-phenanthroline; §, below the detection limit.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4374190&req=5

Fig3: Effects of neutralization of the proteinase activities of the virocidal effects ofS. maurus palmatusvenom against HCV.S. maurus palmatus venom (30 μg/ml) was treated with a metalloproteinase inhibitor (1, 10-phenan-throline; 5 mM) at 4°C or 60°C for 20 min. The treated venom was mixed with HCV for 2 hr at 37°C and the mixture was inoculated to Huh7.5 cells for 2 hr at 37°C. The cells were cultivated in the absence of the venom for one day. The culture supernatants were titrated for virus infectivity (A) and the cells were subjected to immunoblot analysis using monoclonal antibody against the HCV NS3 protein (B). GAPDH served as an internal control to verify equal amounts of sample loading. Data represent means ± SEM of the data obtained from two independent experiments. 1,10 Ph., 1,10-phenanthroline; §, below the detection limit.
Mentions: In order to investigate whether anti-HCV activity of S. maurus palmatus venom involves an enzymatic activity, we treated the venom (30 μg/ml) with heating at 60°C for 20 min or a metalloproteinase inhibitor, 1, 10-phenan-throline (5 mM) to inactivate them, as reported by other investigators [31-34]. The treated venom was added to HCV and incubated for 2 hr at 37°C. Then, the virus/venom mixture was inoculated to Huh7.5 cells and virus replication was analyzed. The results obtained revealed that the treated venom, either treated with heating at 60°C or the metalloproteinase inhibitor, or both at the same time, still markedly suppressed production of HCV infectious particles in the culture to the same extent compared to the untreated control (Figure 3A). Consistent with this observation, accumulation of intracellular HCV NS3 protein was also inhibited (Figure 3B).Figure 3

Bottom Line: Development of well-tolerated regimens with high cure rates and fewer side effects is still much needed.S. maurus palmatus venom is considered as a good natural source for characterization and development of novel anti-HCV agents targeting the entry step.To our knowledge, this is the first report describing antiviral activities of Egyptian scorpion venoms against HCV, and may open a new approach towards discovering antiviral compounds derived from scorpion venoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, Faculty of Science, Al-Azhar University, Assiut, Egypt. sci.elbitar@gmail.com.

ABSTRACT

Background: Hepatitis C virus (HCV) is a major global health problem, causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Development of well-tolerated regimens with high cure rates and fewer side effects is still much needed. Recently, natural antimicrobial peptides (AMPs) are attracting more attention as biological compounds and can be a good template to develop therapeutic agents, including antiviral agents against a variety of viruses. Various AMPs have been characterized from the venom of different venomous animals including scorpions.

Methods: The possible antiviral activities of crude venoms obtained from five Egyptian scorpion species (Leiurus quinquestriatus, Androctonus amoreuxi, A. australis, A. bicolor and Scorpio maurus palmatus) were evaluated by a cell culture method using Huh7.5 cells and the J6/JFH1-P47 strain of HCV. Time-of-addition experiments and inactivation of enzymatic activities of the venoms were carried out to determine the characteristics of the anti-HCV activities.

Results: S. maurus palmatus and A. australis venoms showed anti-HCV activities, with 50% inhibitory concentrations (IC₅₀) being 6.3 ± 1.6 and 88.3 ± 5.8 μg/ml, respectively. S. maurus palmatus venom (30 μg/ml) impaired HCV infectivity in culture medium, but not inside the cells, through virocidal effect. The anti-HCV activity of this venom was not inhibited by a metalloprotease inhibitor or heating at 60°C. The antiviral activity was directed preferentially against HCV.

Conclusions: S. maurus palmatus venom is considered as a good natural source for characterization and development of novel anti-HCV agents targeting the entry step. To our knowledge, this is the first report describing antiviral activities of Egyptian scorpion venoms against HCV, and may open a new approach towards discovering antiviral compounds derived from scorpion venoms.

Show MeSH
Related in: MedlinePlus