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Broad-spectrum antiviral activity of chebulagic acid and punicalagin against viruses that use glycosaminoglycans for entry.

Lin LT, Chen TY, Lin SC, Chung CY, Lin TC, Wang GH, Anderson R, Lin CC, Richardson CD - BMC Microbiol. (2013)

Bottom Line: These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs).CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at μM concentrations and in dose-dependent manners without significant cytotoxicity.Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.

ABSTRACT

Background: We previously identified two hydrolyzable tannins, chebulagic acid (CHLA) and punicalagin (PUG) that blocked herpes simplex virus type 1 (HSV-1) entry and spread. These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs). Based on this property, we evaluated their antiviral efficacy against several different viruses known to employ GAGs for host cell entry.

Results: Extensive analysis of the tannins' mechanism of action was performed on a panel of viruses during the attachment and entry steps of infection. Virus-specific binding assays and the analysis of viral spread during treatment with these compounds were also conducted. CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at μM concentrations and in dose-dependent manners without significant cytotoxicity. Moreover, the natural compounds inhibited viral attachment, penetration, and spread, to different degrees for each virus. Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses.

Conclusions: CHLA and PUG may be of value as broad-spectrum antivirals for limiting emerging/recurring viruses known to engage host cell GAGs for entry. Further studies testing the efficacy of these tannins in vivo against certain viruses are justified.

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Related in: MedlinePlus

Evaluation of antiviral activities of CHLA and PUG that affect virus attachment and penetration. (A) Schematics of the experiments with the virus concentration (PFU/well or MOI) and the time of addition and treatment with tannins (i, ii, iii) for each virus in the associated tables. In virus attachment analysis by Method 1 (light gray bars), monolayers of different cell types were pre-chilled at 4°C for 1 h, and then co-treated with the respective viruses and test compounds at 4°C (1.5 – 3 h; i) before washing off the inoculates and test compounds for subsequent incubation (37°C; ii) and examination of virus infection. In virus penetration analysis (dark gray bars), seeded cell monolayers were pre-chilled at 4°C for 1 h and then challenged with the respective viruses at 4°C for 1.5 – 3 h (i). Cells were then washed and treated with the test compounds for an additional incubation period (ii) during which the temperature was shifted to 37°C to facilitate viral penetration. At the end of the incubation, extracellular viruses were removed by either citrate buffer (pH 3.0) or PBS washes and the cells were further incubated (iii) for analysis of virus infection. Results for (B) HCMV, (C) HCV, (D) DENV-2, (E) MV, and (F) RSV are indicated in each additional panel. Data are plotted against the DMSO negative control treatment of virus infection and are presented as means ± SEM from three independent experiments. See text for details.
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Figure 4: Evaluation of antiviral activities of CHLA and PUG that affect virus attachment and penetration. (A) Schematics of the experiments with the virus concentration (PFU/well or MOI) and the time of addition and treatment with tannins (i, ii, iii) for each virus in the associated tables. In virus attachment analysis by Method 1 (light gray bars), monolayers of different cell types were pre-chilled at 4°C for 1 h, and then co-treated with the respective viruses and test compounds at 4°C (1.5 – 3 h; i) before washing off the inoculates and test compounds for subsequent incubation (37°C; ii) and examination of virus infection. In virus penetration analysis (dark gray bars), seeded cell monolayers were pre-chilled at 4°C for 1 h and then challenged with the respective viruses at 4°C for 1.5 – 3 h (i). Cells were then washed and treated with the test compounds for an additional incubation period (ii) during which the temperature was shifted to 37°C to facilitate viral penetration. At the end of the incubation, extracellular viruses were removed by either citrate buffer (pH 3.0) or PBS washes and the cells were further incubated (iii) for analysis of virus infection. Results for (B) HCMV, (C) HCV, (D) DENV-2, (E) MV, and (F) RSV are indicated in each additional panel. Data are plotted against the DMSO negative control treatment of virus infection and are presented as means ± SEM from three independent experiments. See text for details.

Mentions: In method 1 (Figure 4A), different cell types were pre-chilled at 4°C for 1 h and then co-treated with dose of respective viruses and test compounds at 4°C for the indicated times. The inocula and drugs were removed and the cell monolayers were washed with ice-cold PBS twice before applying the overlay medium. After further incubation at 37°C, plaque assays, EGFP expression analysis, or luciferase assay were performed as described above to assess host cell infection.


Broad-spectrum antiviral activity of chebulagic acid and punicalagin against viruses that use glycosaminoglycans for entry.

Lin LT, Chen TY, Lin SC, Chung CY, Lin TC, Wang GH, Anderson R, Lin CC, Richardson CD - BMC Microbiol. (2013)

Evaluation of antiviral activities of CHLA and PUG that affect virus attachment and penetration. (A) Schematics of the experiments with the virus concentration (PFU/well or MOI) and the time of addition and treatment with tannins (i, ii, iii) for each virus in the associated tables. In virus attachment analysis by Method 1 (light gray bars), monolayers of different cell types were pre-chilled at 4°C for 1 h, and then co-treated with the respective viruses and test compounds at 4°C (1.5 – 3 h; i) before washing off the inoculates and test compounds for subsequent incubation (37°C; ii) and examination of virus infection. In virus penetration analysis (dark gray bars), seeded cell monolayers were pre-chilled at 4°C for 1 h and then challenged with the respective viruses at 4°C for 1.5 – 3 h (i). Cells were then washed and treated with the test compounds for an additional incubation period (ii) during which the temperature was shifted to 37°C to facilitate viral penetration. At the end of the incubation, extracellular viruses were removed by either citrate buffer (pH 3.0) or PBS washes and the cells were further incubated (iii) for analysis of virus infection. Results for (B) HCMV, (C) HCV, (D) DENV-2, (E) MV, and (F) RSV are indicated in each additional panel. Data are plotted against the DMSO negative control treatment of virus infection and are presented as means ± SEM from three independent experiments. See text for details.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750913&req=5

Figure 4: Evaluation of antiviral activities of CHLA and PUG that affect virus attachment and penetration. (A) Schematics of the experiments with the virus concentration (PFU/well or MOI) and the time of addition and treatment with tannins (i, ii, iii) for each virus in the associated tables. In virus attachment analysis by Method 1 (light gray bars), monolayers of different cell types were pre-chilled at 4°C for 1 h, and then co-treated with the respective viruses and test compounds at 4°C (1.5 – 3 h; i) before washing off the inoculates and test compounds for subsequent incubation (37°C; ii) and examination of virus infection. In virus penetration analysis (dark gray bars), seeded cell monolayers were pre-chilled at 4°C for 1 h and then challenged with the respective viruses at 4°C for 1.5 – 3 h (i). Cells were then washed and treated with the test compounds for an additional incubation period (ii) during which the temperature was shifted to 37°C to facilitate viral penetration. At the end of the incubation, extracellular viruses were removed by either citrate buffer (pH 3.0) or PBS washes and the cells were further incubated (iii) for analysis of virus infection. Results for (B) HCMV, (C) HCV, (D) DENV-2, (E) MV, and (F) RSV are indicated in each additional panel. Data are plotted against the DMSO negative control treatment of virus infection and are presented as means ± SEM from three independent experiments. See text for details.
Mentions: In method 1 (Figure 4A), different cell types were pre-chilled at 4°C for 1 h and then co-treated with dose of respective viruses and test compounds at 4°C for the indicated times. The inocula and drugs were removed and the cell monolayers were washed with ice-cold PBS twice before applying the overlay medium. After further incubation at 37°C, plaque assays, EGFP expression analysis, or luciferase assay were performed as described above to assess host cell infection.

Bottom Line: These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs).CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at μM concentrations and in dose-dependent manners without significant cytotoxicity.Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.

ABSTRACT

Background: We previously identified two hydrolyzable tannins, chebulagic acid (CHLA) and punicalagin (PUG) that blocked herpes simplex virus type 1 (HSV-1) entry and spread. These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs). Based on this property, we evaluated their antiviral efficacy against several different viruses known to employ GAGs for host cell entry.

Results: Extensive analysis of the tannins' mechanism of action was performed on a panel of viruses during the attachment and entry steps of infection. Virus-specific binding assays and the analysis of viral spread during treatment with these compounds were also conducted. CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at μM concentrations and in dose-dependent manners without significant cytotoxicity. Moreover, the natural compounds inhibited viral attachment, penetration, and spread, to different degrees for each virus. Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses.

Conclusions: CHLA and PUG may be of value as broad-spectrum antivirals for limiting emerging/recurring viruses known to engage host cell GAGs for entry. Further studies testing the efficacy of these tannins in vivo against certain viruses are justified.

Show MeSH
Related in: MedlinePlus