Antiviral activity of red propolis against herpes simplex virus-1

Abstract

Brazilian Red Propolis is a resinous material produced by Apis mellifera bees through the collection of the exudates of Dalbergia ecastaphyllum, rich in flavonoids, and Symphonia globulifera and Clusia species, which are rich in polyprenylated benzophenones. More than 200 compounds, including flavonoids and polyprenylated benzophenones have been found in Brazilian red propolis. The objective of the present study was to evaluate the chemical composition and antiviral activity of an ethanolic extract of red propolis from Alagoas, Brazil, against Herpes Simplex Virus (HSV-1). In the HPLC-PDA-ESI-MS/MS analysis were detected flavanones, isoflavones, chalcones, pterocarpans and polyprenylated benzophenones. The measurement of antiviral activity of red propolis extract was performed by DNA quantification through quantitative real-time PCR assay and negative staining Electron Microscopy. The pretreatment, post-treatment, and virucide assays using ethanolic extract of red propolis with concentration of 8, 12, 24, 48, or 96 µg/mL, indicated an inhibition of the viral binding and viral entry into cells as well as the replication of HSV-1. In the electron microscopy imaging was observed the disruption of the viral membrane in the HSV-1 treated with red propolis, when compared with HSV-1 that was treated with phosphate buffered saline alone, indicating that ethanolic extract from red propolis can act directly on the viral envelope, through lipid membrane degradation and/or directly blocking the enriched proteins on the viral surface.