| Locoweed is a general term for poisonous plants in Oxytropis DC.、Astragalus L.and Sphaerophysa DC.,which can cause food poisoning in animals with a long-period feeding.It has been found that the indole alkaloids swainsonine is the main toxic substance containing in locoweed.Another study shows that swainsonine has a variety of medicinal activity such as antiviral infection,immune-enhancement,anti-tumor,tumor cell metastasis inhibition,anti HIV potential and so on.In view of the above situation,the present study has the following problems: 1.There is no detoxification drug with good effect has been found which specific to livestock locoweed poisoning.2.The antiviral mechanism of swainsonine from locoweed is not clear.Starting from locweed poisoning mechanism,through regulating the quantitative relationship between swainsonine and α-mannosidase,Sukang detoxification oral solution was created as the cure medicine.The pharmacodynamics and clinical treatment test have been done separately.This paper discussed the effect of swainsonine on antiviral mechanism in vivo and in vitro respectively and the effect of swainsonine on the body-related cytokines from the perspective of immunology.The following experimental studies are carried out and some conclusions are drawn.(1)Through establishing poisoning model which feeds rabbit with Astragalus,and making use of such methods as clinical observation,weighing,testing α-mannosidase and pathology observation to study the pesticide effect of Su Kang detoxification oral solution on Astragalus poisoning.The experimental results indicated that the three experimental groups of rabbits occurred symptoms of poisoning in about 18 days.It showed that the artificial detoxifications experimental rabbit model was established successfully.Pathology slices observation showed that the organs of the intoxication group rabbits showed serious pathological changes such as congestion,inflammation,necrosis,etc.,and the detoxification treatment group showed mild gore,mild cell degeneration.The Su Kang detoxification oral solution can effectively improve the α-mannose glycosides enzyme activity and the detoxifying group exhibited mild pathological changes,which confirmed the Su Kang detoxification oral solution has a good detoxifying effect.(2)Through the clinical treatment test evaluation of Su Kang detoxification oral solution on a suddenly suspected locoweed poisoning case in Small Tail Han sheep,a total of 131,obtained the following conclusion: the certain cause of poisoning was Oxytropisochrocephala poisoning through diagnosis and inquiry and the cure rate of Su Kang detoxification oral solution reached up to 77.86%.Therefore,the test proved a good detoxification effect which can act as the clinically used drugs.(3)The inhibiting virus multiplication effect and comprehensive killing effect of different concentrations swainsonine was detected respectively by using cell culture techniques combining with CPE observation method and MTT colorimetric method.The results revealed: Under the way of swainsonine after virus,IC50 is 1.018×103ng/m L,TI is 2.5;Under the way of synthetic action,IC50 is 782ng/m L,TI is 3.2.After the TI of different mode of action was compared,the test showed that the comprehensive killing effect on BVDV of swainsonine(65.3%,P < 0.01)and the inhibition effect of swainsonine on the multiplication of BVDV(65.1%,P < 0.01)were better;It showed that swainsonine could inhibited the multiplication of BVDV,and directly killed the free BVDV particles.(4)Through established mice infected BVDV model,used different doses of swainsonine to treat infected mice,the conclusions showed that: After 24~48 hour of treatment,the diarrhea symptoms of mice were significantly alleviated and retarded than that of the virus group,the results of pathological examination of liver,kidney,heart,lung and spleen of mice in each group were compared.The severity of the virus infection in each experimental group were: viral infection group(B2)> swainsonine in low dose group(1/5LD50)(B4)> swainsonine in high dose group(1/5LD50)(B3)or ribavirin group(B5).Therefore,Swainsonine still has certain antiviral effect in vivo.(5)The sandwich ELISA method was used to detect the levels of IFN-alpha and IFN-beta,and the conclusions were following: Swainsonine could influenced the antiviral immune response by increasing the expression level of IFN-alpha and IFNbeta significantly.It showed that swainsonine could promoted IFN-alpha and IFN-beta cells induced synthesis of antiviral protein toxin,exerting indirect antiviral impact.And it could also increase the expression of MHC molecules by regulating the activation of BVDV susceptible cells,such as T cells and B cells,and promote the formation of CD8+T cell response,thus killing target cells infected with the virus.(6)The sandwich ELISA method was used to detect the expression levels of costimulatory molecule CD80/CD86,The results demonstrated that swainsonine could influenced the antiviral immune response by increasing the expression level of costimulatory molecule CD80/CD86 significantly.It showed that swainsonine could upregulate expression levels of costimulatory molecules CD80 and CD86,stimulate the activation of T cells,produce lymphokines,and lead the target cells to dissolve and destroy.(7)The sandwich ELISA method was used to detect the expression levels of IL-1、IL-4、IL-15、IL-12、IL-6 and IL-10 respectively,the result is following:swainsonine could influence the antiviral immune regulation by increasing the expression level of IL-1、IL-4、IL-15、IL-12 and IL-6 significantly.It showed that swainsonine could upregulate expression levels of them,stimulatie and promote the proliferation and activation of B cells and T cells,Enhance cellular immune response,And through the target cell killing function to affect the body’s antiviral immunity regulation.Swainsonine could influence the antiviral immune regulation by reducing the expression level of IL-10 significantly.It showed that swainsonine could downregulate expression levels of IL-10,produce Th2 immune response inhibition,It is speculated that the anti-viral immune response induced by swainsonine is the main way of cellular immune response.In conclusion,Su Kang detoxification oral solution had a good detoxification effect on locoweed poisoning livestock.The bioactive component swainsonine,which extracted from locoweed have good anti-viral effect.The mechanism of swainsonine antiviral action may be that swainsonine can enter the animal body to inhibit the proliferation of BVDV or direct inactivation of free BVDV,and can promote and stimulate the expression of related cytokines up or down,induce the body autoimmune response,synergistically play an antiviral effect. |
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