An In Vivo Study Of The Efficacy And Mechanism Of Anacardic Acid Against Echinococcosis

Objective:To explore the in vivo efficacy and mechanism of anacardic acid against echinococcosis.Methods:Establishing the mice model of echinococcosis by infecting with protoscolices of E.m/E.g.The efficacy of anacardic acid against echinococcosis was analyzed by following methods:(1)Weighing the weight of hydatid cyst.(2)Observing the changes of microstructure of E.g cysts.(3)Observing the pathological changes of E.m cysts.(4)Counting the number of lymphocyte in spleens of the mice infected withprotoscolices of E.m with the FCM.(5)Detecting the levels of IL-4 and IFN-γin blood by ELISA.The mechanism of anacardic acid against E.m metacestodes was analyzed by following methods:(1)Detecting the levels of VEGF in blood by ELISA.(2)Detecting CD34 in E.m cysts and the surrounding liver tissues by IHC.Results:1)The weight of hydatid cyst was significantly increased in the model group,while that in the anacardic acid group was obviously lower than the control group(P<0.05).The germinal layer of the hydatid cyst in anacardic acid group was obviously destroyed.2)Anacardic acid could improve the immune function of E.g and E.m model mice.Compared with E.g/E.m model mice,the level of IL-4 in serum was significantly increased(P<0.05),but that of IFN-γno marked change.Compared with E.m model mice,CD4~+T cells and CD8~+T cells were all significantly increased(P<0.05).Both CD4~+PD-1~+T cells and CD8~+PD-1~+T cells were obviously decreased(P<0.05).3)Anacardic acid could inhibit the angiogenesis of E.m cyst.Compared with model mice,the level of VEGF in serum of the mice treated with anacardic acid was decreased(P<0.05).The expressions of CD34 in E.m cyst and the surrounding liver tissues were significantly decreased(P<0.05).Conclusion:1)Anacardic acid can significantly inhibits the growth of hydatid cyst in vivo.It can obviously damage the germinal layer of hydatid cyst.The agent could be potential in clinical application against echinococcosis.2)Anacardic acid can improve the immune functions of the echinococcosis model mice by regulating the level of IL-4 and IFN-γ,inducing the proliferation of CD4~+T&CD8~+T cells and down-regulating PD-1,a negative regulator on the T cell surface.3)Anacardic acid can depress the expression of VEGF in serum of E.m model mice and the expression of CD34 in E.m cyst and the surrounding liver tissues,through which the angiogenesis of E.m metacestodes is inhibited.