Abstract:
Investigation on the effect of root bark and wood, stem bark and wood, leaves and sap of Synadenium
glaucescens extracts against Newcastle disease (ND) virus was done using an in ovo assay. Viable 9
days embryonated chicken eggs were arranged into 25 treatment groups (n = 5). Groups 1 to 21 were
challenged with a 13C/SUA virulent strain of ND virus treated with extract at concentration of 0.2 mg/ml.
Un-inoculated group saved as negative control and groups inoculated with virus and diluent saved as
positive controls. Haemagglutination test was used to quantify the amount for ND virus units. Embryo
survival and embryo weight were significantly higher (P ≤ 0.05) in groups treated with S. glaucescens
extracts than the positive control. The root bark demonstrated significantly higher antiviral activities (P
≤ 0.05). Furthermore, treatments with ethanolic extract SE1 resulted into 100% embryo survival, 91.2%
mean embryo weight and reduced viral load by 99.2%. The minimum dose of SE1 with the highest
efficacy was 0.2 mg/ml. The percent mean embryo weight and haemagglutination test demonstrated
negative correlation (R2 = 0.94). These findings validate the ethnoveterinary potential of S. glaucescens
and the feasibility of its use for treatment and control of ND.
