Preparation Of Water-soluble Yeast Glucan And Effect On Immune Function In Rabbit

The purpose of this study was to develop steady, safe, nontoxic water-soluble yeast glucan, and research its other aspect functions in antibiotic action and the immunity function on rabbit.1. Preparation and content determination of water-soluble yeast glucan This test charged water-insoluble yeast glucanle to water-soluble yeast glucan by the method of chemical modification, and established a method of determination of yeast glucan content using the phenol-sulfuric acid reaction based on other determinated method of polysaccharide content. This method showed a good linear relationship in the range of 0.010~0.500mg/mL. Its linear equation is y=2.025x+0.1986,r~2=0.9916; and the content of water-soluble is 85%. The repeatability, recovery and stability of this method were detected in this experiment. The results showed that this method can be used for the determinating of water-soluble yeast glucan content.2. Safety performance of yeast glucan injection In order to safely use yeast gulcan injection on clinic, this test applied water-soluble yeast glucan injection to New Zealand rabbits and mice by vein, muscle and intraperitoneal injection to test its pyrogenicity, irritation and toxicity. Results were showed as following: the pyrogen of water-soluble yeast glucan within the prescribed scope and its average muscle response is one, so water-soluble can be given by injection; the biggest dosage of water-soluble yeast glucan on mice was 12 g/kg which overed the safe standards 10 g/kg, So water-soluble is low toxicity drug and can be safely used in clinic.3. Bacteriostasis and anti-infection test of water-soluble yeast glucan In order to research the bacteriostasis and anti-infection of water-soluble yeast glucan, this test adopted the method of antimicrobial susceptibility disc diffusion and anti-infection test against staphylococcus aureus, Escherichia coli and Streptococcus dysgalactiae. The result showed water-soluble yeast glucan has certain antibacterial ability in vitro against staphylococcus aureus; and has nothing impact against Escherichia coli and Streptococcus dysgalactiae; but it can obviously increase mice's anti-infection ability in body against staphylococcus, Escherichia coli and Streptococcus dysgalactiae.4. Preparation of yeast glucan enhanced vaccine and immune protective test In order to get a stable, safe and high effective vaccine, yeast glucan was administrated by injection with inactive vaccine which was prepared in bovine-derived Staphylococcus aureus and oil emulsion to get yeast glucan enhanced vaccine. The present study investigated the safety of yeast glucan enhanced vaccine for mice and New Zealand Rabbit those was injected this vaccine;and also investigated its high protection rate. The result showed yeast glucan enhanced vaccine accorded with the requirement of vaccine and had a high immune protective rate compared with ordinary vaccine.5. Effect of Yeast Glucan Enhanced Vaccine on the Immune Function in New Zealand Rabbit The present study investigated the effects of yeast glucan enhanced vaccine on immune function of New Zealand Rabbit. Yeast glucan was administrated by injection with inactive vaccine which was prepared in Staphylococcus aureus and oil emulsion in three doses (5, 10, 15 g/ L), group was set without yeast glucan. Blood samples were collected after 7th, 14th, 21th, 31th, 41th, and 51th day after incubation from New Zealand Rabbits, and lymphocyte transformation rate and the antibody levels were evaluated corresponding. The results indicated that enhanced vaccine with 10 mg per rabbit could significantly enhance the lymphocyte transformation rate and the antibody levels. So inactivated vaccine that added proper amount of yeast glucan can improve the vaccine effectiveness and enhance the immune function of New Zealand Rabbit.