alexa Broad and potent anti-influenza virus spectrum of epigallocatechin-3-O-gallate-monopalmitate | Open Access Journals
ISSN: 1747-0862
Journal of Molecular and Genetic Medicine
Make the best use of Scientific Research and information from our 700+ peer reviewed, Open Access Journals that operates with the help of 50,000+ Editorial Board Members and esteemed reviewers and 1000+ Scientific associations in Medical, Clinical, Pharmaceutical, Engineering, Technology and Management Fields.
Meet Inspiring Speakers and Experts at our 3000+ Global Conferenceseries Events with over 600+ Conferences, 1200+ Symposiums and 1200+ Workshops on
Medical, Pharma, Engineering, Science, Technology and Business

Broad and potent anti-influenza virus spectrum of epigallocatechin-3-O-gallate-monopalmitate

Kunihiro Kaihatsu1,4,*, Shuichi Mori1,4, Hiroyo Matsumura1, Tomo Daidoji2, Chiharu Kawakami3, Hideshi Kurata3, Takaaki Nakaya2, Nobuo Kato1

1Department of Organic Fine Chemicals, Institute of Scientific and Industrial Research, Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan,

2International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1, Yamadaoka, Suita, Osaka 565-0871, Japan,

3Yokohama City Institute of Health, 1-2-17, Takigashira, Isogo-ku, Yokohama 235-0012, Japan

4These authors contributed equally to this work

*Corresponding Author:
Kunihiro Kaihatsu
Tel: +81 668798471
Fax: +81 668798474
E-mail: [email protected]

Received date: 03 September 2009, Revised date: 15 December 2009, Accepted date: 15 December 2009, Published online 16 December 2009

Citation: J Mol Genet Med (2009), 3(2), 195-197

© Copyright The Authors: This is an open access article, published under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/). This license permits noncommercial use, distribution and reproduction of the article, provided the original work is appropriately acknowledged with correct citation details.

Visit for more related articles at Journal of Molecular and Genetic Medicine

Numerous influenza pandemics in the last century resulted in the death of millions of people worldwide. With the current and future threats of influenza pandemics development of new antiviral compounds remains a great demand. However, currently only a limited number of drugs are available for the treatment and prophylaxis of influenza. A neuraminidase (NA) inhibitor, oseltamivir phosphate, is the most commonly used antiviral drug. However, a number of reports suggest the emergence of oseltamivir phosphate resistance in new seasonal influenza viruses and highly pathogenic avian influenza (H5N1) (for example, de Jong et al, 2005).

(–)-Epigallocatechin-3-O-gallate (EGCG: 1), a major component of green tea plant (Camellia sinensis), has been recognized to possess antiviral properties. Reports on the anti-influenza activity of 1 found that it inhibited virus adsorption (Nakayama et al, 1993), as well as acidification of endosomes and lysosomes (Imanishi et al, 2002). Such virus inhibition activity is different from other current NA or proton pump inhibitors, suggesting that 1 can be developed into a new class of antiviral compounds that are effective against current drug resistant influenza strains. However, 1 has not been used as an antiviral compound because of its poor lipid membrane permeability and low chemical stability. It was previously reported that the introduction of long alkyl chain groups to 1 improved its lipid membrane permeability (Tanaka et al, 1998), while protection of its hydroxyl groups with acyl groups increased its chemical stability under physiological conditions (Lam et al, 2004). Recently, we reported a method to synthesize EGCG-fatty acid monoesters using lipase-catalyzed transesterification and demonstrated that EGCG-fatty acids monoesters possessed improved influenza virus inhibitory effect against influenza A/PR8/34/(H1N1) in an alkyl length dependent manner (Mori et al, 2008). Here, we investigated the spectrum of influenza virus inhibition activity of EGCG (1) and EGCG-C-16 (2). As shown in Figures 1a, 2 is a mixture of four regio-isomers and the ratio of each regio-isomer 2a:2b:2c:2d is 38:35:7:20, respectively. Because the B-ring-modified esters (2a and 2b) and D-ring-modified esters (2c and 2d) showed exactly the same antiviral activities (data not shown), we used the mixture of four regio-isomers (2a-d) in the following assays.

molecular-genetic-medicine-Avian-influenza-virus-inhibition

Figure 1. A. Chemical structure of EGCG (1) and EGCG-C16 (2). 2 is a mixture of four regio-isomers (2a-d). 2a: R2=R3= R4=H, R1= CO(CH)14CH3, 2b: R1=R3=R4=H, R2= CO(CH)14CH3, 2c: R1=R2=R4=H, R3= CO(CH)14CH3 , 2d: R1=R2=R3=H, R4= CO(CH)14CH3. B. Avian influenza virus inhibition activity of 1 and 2 in chicken embryonated eggs. Influenza A/Duck/Hong Kong/342/78 (H5N2) was pretreated with or without 1.0μM compounds and then inoculated (50 pfu/egg) into the allantoic fluid of embryonated eggs for 7 days at 37 °C. Open circle, no compound; Closed circle, 1.0μM EGCG-16 (2); Open square, 1.0μM EGCG (1); Closed square, 1.0μM Zanamivir; Open lozenge, 1.0μM Oseltamivir phosphate.

A series of human influenza viruses, an experimental strain (A/Puerto Rico/8/34/(H1N1)), vaccine strains (A/Beijing/262/95/(H1N1), A/Panama/2007/99/(H3N2), and B/Yamanashi/166/98/), drug-resistant strains (Yokohama/77/2008/(H1N1) OPR: oseltamivir phosphate-resistant (OPR), Yokohama/63/2007/(H1N1) AR: amantadine-resistant (AR), A/Yokohama/91/2008/(H1N1) OPR/AR: (OPR/AR) and avian pathogenic influenza (A/Duck/Hong Kong/342/78/(H5N2)), were directly incubated with 1 or 2 for 30 min prior to inoculation into MDCK cells. The cells were inoculated with virus, with or without the compounds, for 1hr, and the direct virus inhibitory effects were assessed by a plaque formation assay at 54hr post-incubation. The plaque inhibition activity was calculated relative to no compound. The cytotoxicity of compounds on MDCK cells were evaluated by the MTT cell proliferation assay. Briefly, the cells were incubated with 1 or 2 for 24hr for the MTT assay. The results of the plaque inhibition assay and MTT assay are expressed as mean ± standard error of three independent experiments.

We also investigated the virus inhibition activity of 1 and 2 on avian influenza A/Duck/Hong Kong/342/78 (H5N2) virus in ovo using 11-day-old chicken embryonated eggs (n=12) inoculated with compound-treated or untreated viruses.

As shown in Table 1, both 1 and 2 showed broad virus inhibitory effects on MDCK cells. The EC50 values of 2 on these viruses were between 10 to 61nM, which were approximately 7.1 to 44-fold lower than those of 1. The CC50 value of 2 was 82μM, which was only 3.1-fold lower than that of 1 (255 μM). Thus, the SI value of 2 was improved 2.2 to 14-fold compared to 1.

Table 1

Table 1. Direct virus inhibitory effect of 1 and 2 based on the plaque formation assay

With respect to the avian influenza virus inhibition assay in ovo, virus treated with 1, zanamivir, or oseltamivir phosphate showed a moderate viral inhibitory effect (Figures 1b). However, 2 almost completely inhibited the infection (Figures. 1b), and the efficacy was retained even at 0.1μM (data not shown).

In summary, 2 inhibited human and avian influenza A and B viruses, including drug-resistant viruses. 2 was found to be more effective than neuraminidase inhibitors, and strongly inhibited the infection of avian influenza (H5N2) virus in chicken embryonated eggs. This unique viral inhibitory action has the potential to be utilized to effectively control a broad spectrum of influenza viruses.

Acknowledgements

This study was supported by the Industrial Technology Research Grant Program in 2006 from New Energy and Industrial Technology Development Organization (NEDO) of Japan.

Competing Interests

None declared.

References

Select your language of interest to view the total content in your interested language
Post your comment

Share This Article

Relevant Topics

Article Usage

  • Total views: 11617
  • [From(publication date):
    December-2009 - Sep 20, 2017]
  • Breakdown by view type
  • HTML page views : 7836
  • PDF downloads :3781
 

Post your comment

captcha   Reload  Can't read the image? click here to refresh

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords