Avian metapneumovirus (aMPV) is a negative-sense single-stranded RNA enveloped virus of the Metapneumovirus genus belonging to the Paramyxoviridae family. This virus may cause significant economic losses to the poultry industry, despite vaccination, which is the main tool for controlling and preventing aMPV. The aim of this study was to evaluate the antiviral activity of extracts of four different native plants of the Brazilian Cerrado against aMPV. The antiviral activity against aMPV was determined by titration. This technique measures the ability of plant extract dilutions (25 to 2.5 μg mL -1 ) to inhibit the cytopathic effect (CPE) of the virus, expressed as inhibition percentage (IP). The maximum nontoxic concentration (MNTC) of the extracts used in antiviral assay was 25 μg mL -1 for Aspidosperma tomentosum and Gaylussacia brasiliensis, and 2.5 μg mL -1 for Arrabidaea chica and Virola sebifera. Twelve different extracts derived from four plant species collected from the Brazilian Cerrado were screened for antiviral activity against aMPV. G. brasiliensis, A. chica, and V. sebifera extracts presented inhibition rates of 99% in the early viral replication stages, suggesting that these extracts act during the adsorption phase. On the other hand, A. tomentosum inhibited 99% virus replication after the virus entered the cell. The biomonitored fractioning of extracts active against aMPV may be a tool to identify the active compounds of plant extracts and to determine their precise mode of action.

No abstract