Evaluation of secondary metabolites of herbal plant extracts as an antiviral effect on infectious bursal disease virus isolates in embryonated chicken eggs

Background and Aim: Infectious bursal disease attacks the poultry industry, mainly young chickens, causing immunosuppression, and death with high economic losses. This study aimed to evaluate the effects of the monoextract, diextracts, and triextracts of Quercus infectoria (QI), Citrus aurantifolia (CiA), and Coffea arabica (CoA) on infectious bursal disease virus (IBDV) in embryonated chicken eggs (ECEs). Materials and Methods: The experimental design consisted of three sets of ECEs at 11 days of age, and each set included seven groups (G1-G7). The extracts of QI, CiA, and CoA were inoculated to ECEs by the chorioallantoic membrane method before, in concomitant (mixed) with, and after IBDV infection to the first, second, and third sets, respectively. The monoextract, diextracts, and triextracts of QI, CiA, and CoA were given at 1%, 2%, 5%, and 10% concentrations to G1-G3, G4-G6, and G7, respectively. Real-time polymerase chain reaction identified and confirmed the virus in accordance with the pathological changes. Results: The monoextract (5-10% concentrations) inhibited IBDV and had no effect on viral infection preinoculation, whereas the monoextract (10% concentration) inhibited IBDV during mixed inoculation and post-inoculation. Diextracts (2-10% concentrations) inhibited IBDV and had no effect on viral infection preinoculation, whereas diextracts (5-10% concentrations) inhibited IBDV during mixed inoculation and post-inoculation. Triextracts (1%, 2%, 5%, and 10% concentrations) inhibited IBDV by ameliorating the pathological changes of the virus and preventing the death of ECEs. Conclusion: The inoculation of herbal extracts, particularly triextracts, alleviates the pathological changes in ECEs infected with IBDV. This study recommends the oral route in evaluating plant extracts against IBDV in poultry