Evaluation of Antiviral Activity of Different Medicinal Plants against Newcastle Disease Virus

Newcastle Disease (ND) is a highly contagious viral disease that has a tremendous negative impact on the poultry industry worldwide. Plant extracts were prepared from five different medicinal plants and applied against Newcastle Disease Virus (NDV) to evaluate the antiviral replication in Specific Pathogen-Free (SPF) chicken embryos. Three dilutions from each plant extract were prepared and mixed with a fixed titer (10⁴ EID₅₀/mL) of virulent NDV strain Herts 33. The mix was inoculated into nine-day-old SPF chicken embryos that were monitored for five days. Real-time PCR and hemagglutination tests were conducted to evaluate the activity of NDV and its viral RNA titer. Some plant extracts showed a complete inhibition of NDV evidenced by the absence of embryo deaths, the absence of HA titer and viral RNA in the allantoic fluid. These plant extracts were from Moringa peregrina (leaves), Acacia cyanophylla (leaves), Eucalyptus camaldulensis (fruits) and Pistacia atlantica (leaves and stems). Other plant extracts showed partial inhibition of NDV, such as Ceratonia siliqua (leaves) and Eucalyptus camaldulensis (leaves). This experiment shows the potential of using medicinal plants as antiviral agents.