Atividade antiviral do extrato de própolis contra o calicivírus felino, adenovírus canino 2 e vírus da diarréia viral bovina

propolis is a resinous substance produced by bees for which several biological activities have been attributed. in this article, the antiviral activity of two propolis extracts was tested against bovine viral diarrhea virus (bvdv), canine adenovirus type 2 (cav-2), and feline calicivirus (fcv). one of the extracts was obtained by ethanolic extraction of propolis from the santa maria (rs) region, while the other was bought from a minas gerais industry. the high efficiency liquid cromatography (hplc) analysis detected the presence of some flavonoids like rutin, quercetin, and gallic acid. the mtt test was applied in order to detect the citotoxicity and also the antiviral activity. both extracts showed antiviral activity against bvdv and cav-2 when incubated with the cell cultures before viral inoculation. the extracts were less effective against fcv comparing to the results for the other viruses and, the antiviral activity was observed only when the própolis was present after virus inoculation the extract obtained in the lab showed the highest selectivity index (si= cc50/ ec50). thus, propolis showed antiviral activity against three different viruses, making it a target for the development of new natural compounds with antiviral activity.