Portuguese winemaking residues as a potential source of natural anti-adenoviral agents

Abstract

To date there are no licensed systemic or topical treatments in Europe or the USA for adenovirus infections. In the present paper, we evaluate the effect of a polyphenol-based grape extract (NE) obtained from Portuguese white-winemaking by-products, and Resveratrol in pure form, on adenovirus type 5 infection. For this purpose, recombinant adenovirus vectors (Ad-5) and a human-derived cell line (293) were used as models. The NE and Resveratrol at the used concentrations do not induce cell cytotoxicity or direct virucidal activity; however, they reduce 4.5 and 6.5 log (TCID₅₀/ml) on total infectious Ad-5 production, respectively. The capacity of Ad-5 replication upon removal of NE and Resveratrol after 24 h post infection was also evaluated. In contrast to Resveratrol, the highest evaluated NE concentration inhibits irreversibly the Ad-5 replication. These results provide useful information for the use of NE and Resveratrol as potential sources of promising natural antiviral agents on Ad-5 infection.

Keywords::

• Grape extract
• Resveratrol
• antiviral activity
• adenovirus
• antioxidants
• phenolic compounds

Acknowledgements

The authors are grateful to Rita Malpique from the Animal Cell Technology laboratory for providing technical support with antiviral assays.

Declaration of interest: Ana Matias is grateful to FC–MCES, Portugal and to Sovena–ComÉrcio e Indústria de Produtos Alimentares, S.A. for financial support, through grant SFRH/BDE/15535/2005. Ana Teresa Serra, Isabel Marcelino and Tiago B. Ferreira also acknowledge FCT–MCTES for financial support, through the grants SFRH/BD/19238/2004, SFRH/BD/14378/2003 and SFRH/BD/10614/2002, respectively.

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.