Preparation Process Of Radix Isatidis Pellet And Its Applicaiton Against IBD Infection In Chickens

Radix isatidis has been recorded to have function of relieving higher fever, cooling bleed andimproving throat distress in traditional Chinese documents. In recent years, it has been widely used inthe formulation of the traditional Chinese veterinary medicines. However, lack of the quality control andthe limited clinical function are delaying the application in animal industries. The current study aims toestablish the quantity control and explore the clinical application. Furthermore, the Radix isatidismedicament will be registered for new veterinary drugs based on the following assays. Firstly, theextracting parameters of the active components of radix isatidis were optimized; subsequently, radixisatidis pellets were developed according the regulation of new veterinary drug. Finally, both preventingand curing function against Infectious Bursal Disease (IBD) were evaluated for clinical applicationbased on the animal model. The detailed tests were described as the follows.(1) Extracting parameters: The extracting protocols were optimized using L9(34) orthogonal testand the several references were employed, such as solvent volume, extraction times, and theconcentration of ethanol. From the optimal extraction, the parameters were described as the followingprocedures, such as12times of solvent volume, twice extractions, one-hour per process and60%ethanol.Consenquently, the extraction yielded15.84%while the adenosine amounted to0.65mg/g.(2) Pellet formulation: Based on the moldings, moisture absorption and solubility factors, theoptimal parameters of radix isatidis pellet complied with the requirement. The ration of radix isatidisextraction, cane sugar and dextrin was1:3:0.1. Moreover, the extracts were diluted with95%ethanolliquid before manufacturing pellets.(3) Inhibition of pathogenic bacteria in vitro: The three pathogens were treated with the differentconcentration of radix isatidis pellets. The MIC of E. coli, Salmonella and P. aeruginosa was100mg/ml,50mg/ml and100mg/ml, respectively.(4) In order to confirm the antiviral function, SPF chicken models were challenged with virulentBC6/85of Infectious Bursal Disease virus (IBDV).210twenty-day-old chickens were divided into7groups; including five groups treated with radix isatidis pellets, group6with6g/L of Astragaluspolysaccharide as the positive control and group7without pellets or challenge as the health control. Thegroup1, group2group3and group5were challenged with BC6/85strain, and then continuallyadministrated the radix isatidis pellets through water with1.5g/L,3g/L and6g/L, respectively for fiveday. Meanwhile, the group4was continually administrated the radix isatidis pellets with3g/L for3days before challenge and lasted for extra2days post challenge. Post challenge, the significantincreasing index of spleen, bursa and thymus indexes were observed in group1, group2, group3andgroup5as compared with group6. Moreover, no significant difference was observed in term of theaverage daily gain, average feed intake and average feed conversation among all groups. From theabove evidence, chickens with3g/L radix isatidis pellets were able to protect the challenge of IBDVinfection and improve the immune functions.