Effect And Mechanism Of Ligusticum Chuanqiong Hort Against Infectious Bursal Disease

Objective:Modeling the IBDV disease; Probing into the efficacy and machnism of effect to LH.Method:Getting the chicks injected with IBDV to the establishment of IBD model, and assessing the establishment via observations of clinical symptom and histopathologic variation. Dividing twenty-one day post-hatched200chicks, healthy and intact, into8groups,25chicks each,which nominated as A, B, C, D, E, F,G and H. A as control group (normal), B as negative group (virus), C, D as positive group (Ribavirin and astragalus).E, F, G and H as experimental group (LH prevention group and LH dose group).28days later, intraperitoneal injection all the chicks with0.2mL Virus except group A which only given0.2mL PBS. E (LH prevention group) begins in25st day by water imbibing. C (ribavirin group) D (astragalus) and F、G、H(LH dose group) begins in31th day by water imbibing. Sample the27th,30th,37th,44th days’ blood after the infection respectively, squeeze serum, assay contents of IFN-y and IL-10in the serum via ELISA, and peripheral T lymphocytes proliferation status via MTT. Examine every chick’s weight, immune organs exponents, and the VP1and TLR3gene of IBDV expression by FQ-PCR.The result turned out:1. After IBDV-BC6/85strain infected chicken, this test successfully established PCR disease models through observing chicks’clinical symptoms and pathological examination.2. Two weeks after infection, the groups of infect MDV lower than control group on weight, and virus group was the lowest. STS goups and Moroxydine groups higher than virus group (P<0.05). Explain STS could improved weigh that MDV inducing loss.2. After infection, the spleen index of virus group higher than control group (P<0.05), the fabricius and thymus indexes of virus group lower than control group (P<0.05).The immune organ indexes of LH groups in between virus and control group. The result indicated LH could promoted development of immune organs, relieved IBDV bringing out injures, strengthened immunity.3. LH can increase the CD4+/CD8+group, and significantly greater than the virus group and control group (P<0.05), the LH promotion effect of high-dose group and prevention group is highest, while the other two was lower than Ribavirin and Astragalus in the control group. LH can promote the proliferation of T lymphocytes, and LH high group and prevention group is most obvious.4.LH groups can improve the ratio of CD4+VCD8+in the peripheral blood lymphocytes and T Cell level, and significantly greater than virus group and blank group (P<0.05), in which LH high dose enhancement effect and prevention group was the highest, while the other two dose groups were lower than control group ribavirin and Radix Astragali polysaccharide. LH can improve the ratio of CD4+/CD8+and T lymphocytes, and LH high dose group and prevention group, the most obvious effect.5.LH group can improve IBDV-Ab and drug control group, high group was most pronounced among them with LH (P<0.01) and significantly higher than that of normal group and virus group, significantly higher than ribavirin group and astragalus group (P<0.05). LH can improve the level of antibodies, in high group the effect is most obvious.6. LH group and drug control group can reduce VP1,low dose of LH group effect is not obvious, the most performance for numerical significantly higher than other groups (P<0.01). That LH can inhibit viral replication, and high dose and middle dose effect is better.7. LH group and drug control group can improve TLR3,ande higher than virus group, high dose group is the most significant (P<0.05). So that LH can promote TLR3,high dose group is the best effect. Conclusion:①The LH can significantly improve the clinical symptoms of IBD chicks;②LH can significantly improve IBD chicks antibody levels and T lymphocyte immune organs index, promote the development of immune organs;③LH can improve the cellular immunity of IBD chicks and raised IFN-quantity, IFN-gamma and beta TLR3expression;④LH can reduce tissue expression of virus protein VP1, inhibit the proliferation of the virus.