In-ovo biological activity of Boswellia dalzielii stem bark extract and fractions against Newcastle disease virus

Newcastle disease remains a disease of global concern and serious economic challenge to the poultry industry because of its high mortality rate, in spite of the various intervention programs including vaccination. This research is aimed at studying the antiviral activity of the extract and fractions of Boswellia dalzielii against Newcastle disease virus (NDV) using chicken embryonated eggs. Phytochemical analysis was conducted using standard procedure. The methanol extract of Boswellia dalzielii  was subjected to solvent- solvent fractionation using solvents of varing polarity. This process generated four fractions namely hexane fraction, ethyl acetate fraction, n-butanol fraction and aqueous fraction. Nine to eleven day-old viable embryonated chicken eggs (ECE) were used for the antiviral assay; these were divided into seven groups of five eggs each. The methanol extract was also screened for its cytotoxicity, prophylatic, therapeutic and neutralization effects against NDV, while the fractions were screened for their cytotoxicity and neutralization effects. The phytochemical screening of the stem bark extract and fractions of B. dalzielii showed the presence of tannins, flavonoids, saponin, terpenoids and steroids.  It was observed from the results that the extract was toxic to the embryo at a concentration above 100 mg/ml. At the end of the bioassay, methanol extract and fractions of B. dalzielii showed antiviral activity against NDV. However, the extract seems to possess the most significant anti-NDV activity than the fractions. The results of the study are very promising and support the use of B. dalzielii in the treatment of viral infections in animals and humans. Key words: Antiviral, Boswellia dalzielii, Newcastle disease virus (NDV), embryonated chicken eggs (ECE).