Research On Immune Enhancement On IBD Vaccine And Antiviral Effect Against IBDV Of Propolis Extracts

Propolis is a natural sticky resinous substance with special aroma collected by honeybees from cracks in the bark of trees and leaf buds enriched with bees’ salivary enzymes, wax and pollen. It had been reported to possess various biological activities and it has unique advantages in many aspects.At present, infection bursal disease( IBD) is still one of infectious diseases threatening poultry industry at home and abroad. If chickens are infected with infection bursal disease virus( IBDV), their Fabricius’ bursa will be damaged and they will be finally immunosuppressed. Now the main method to prevent infection of IBDV is vaccination, but the results are usually unsatisfactory and the risk of outbreaks is still high.The results are as follows:①Different methods of extracting propolis. Six kinds of propolis extracts have been acquired using different extract methods. The contents of flavonoids of these propolis extracts were determined by ultraviolet specterphotometry(UV) with reliable and satisfied results. The results showed that alcohol extract contained the highest content of flavonoids, while water extract contained the lowest content.②Propolis extracts efficacy experiment. This paper compared immune enhancing effect and antiviral effect of three kinds of propolis extracts, in order to analyze the best extract method and using way of propolis extracts for optimal effects.③Results and discussions of different propolis extracts efficacy experiment. The results suggested that propolis extracts have an obvious immune enhancing effect. They can protect chickens from IBD and increase the average weight gain of chickens. They can also alleviate the pathological damage caused by IBD, promote growth of Fabricius’ bursa and improve bursal index. The results showed that application of propolis extracts could significantly increase Ig G, Ig A, Ig M, IL-2, TNF-α and IFN-γ contents in the blood. They can improve both the humoral and celluar immunity level in chickens, thus they can help prevent infection of IBDV. The best result was achieved in the alcohol after water extract group and alcohol after ester after petroleum ether after water extract group.④Collaborative antivirotic experiment of medicine plus propolis extract. The research showed the combination of medicine plus propolis alcohol extract was more effective than medicine alone in improving both the humoral and celluar immunity level. Propolis alcohol extract and medicine can work together to prevent infection of IBDV.