Experimental Study Of Astragalus And Its Combining Forms On Schistosomicidal Effect

As matters stand the cornerstone of control Schistosomiasis is still dependent on praziquantel(PZQ) and Artemisinin.The former mainly acts on adault worms and the latter on 7-21 days old schistosomulums. As to worms yanger than 7 days old,it is still regretful that there is no effective medicine up to now.Recently,just did as other groups,our group also found that the efficience of PZQ,as a schistosomicidal medicine utilized about 30 years,was less than that in the past 10 years. Therefore,to develop novel medicines or a method that augments PZQ effect become urgent in research on schistosomasis control.It was early proved that astragalus,a traditional Chinese medicine,is an immune regulator and has been clinically used spreadly.Recently,its roles in antischistosome were also explored.For exemples,the schistosomicidal effect of PZQ and the efficiencies of vaccines against schistosome could be strengthened by combining with astragalus and astragalus possesses the effect of anti-hepatic fibrosis induced by schistosome eggs.However, it needs to be cleared that whether astragalus played the above roles through directly influencing development of worms or through regulat immune response of host.Furthermore,the action on early stage of schistosoma by combining pumpkin seeds and arecas is also an interesting topic and needs to be proved by experiment.In the study, based on understanding the role of astragalus on combatting schistosoma, the effect of compound combined astragalus with pumpkin seeds and arecas was investigated to provide a supplementary measure for prevention of schistosomasis.【Objectives】To understand the influence of astragalus on development of schistosoma and immune response of host and observe the difference between single administration of astragalus and united administration of astragalus,pumpkin seeds and arecas. 【Methods】Two experiments were set up with Kunming mice as model.In experiment 1,six groups[infection control group,low dosage of astragalus group(0.25g/mouse/d),high dosage of astragalus group (0.50g/mouse/d),astragalus+PZQ group,PZQ group and normal mouse group]were involved to observe the influence of astragalus on development of schistosoma after administration of infected mice with two dosages and investigate the levels of antibodies against egg or antigen and adult worm antigen,proinflammatory cytokine(IL-6), Anti-inflammatory cytokines(IL-10) and hydroxyproline in sera from experimental mice with immunological and biochemical methods to illustrate the effects on immune response of host infected by schistosoma. In experiment 2,9 groups(infected control group,administration of compound 1-10d after infection,administration of compound 8-17d after infection,administration of compound 15-24d after infection, administration of compound 28-37d after infection,administration of pumpkin seeds 1-10d after infection,administration of pumpkin seeds and arecas 1-10d after infection,administration of PZQ 36d after infection at the dose of 150mg/kg.d and administration of PZQ 36d after infection at the dose of 300mg/kg.d) were set up to compare observe the effect differences of the traditional Chinese medicine compounds among different infective stages.【Results】1:After administrated with fixed quantity of single astragalus for 50 days,compared with infective control group,the worm reduce rates of low dosage and high dosage groups of mice were 29.2% and 30.3%,respectively.The worm length reduce rate in former group was 10.49%for male worms and 8.40%for female worms and 10.57% male worm reduce rate and 15.33%female worm reduce rate were found in high dosage group.Egg reduce rates in the two groups were 31.1% and 36.0%,respectively.All differences of above data are these statistical(P＜0.05).Comparing with infected control group,the immune response in both group revealed lower level of anti-SEA antibody (P＜0.05) and IL-6(P＜0.01),and less amounts of hydroxyproline and higher level of IL-10(P＜0.05) and the more amounts of hydroxyproline. 2:In experiment 2,the worm reduce rates of the groups administrated compounds 1-10 days,8-17 days and 15-24 days after infection were 36.21%,26.74%and 39.04%(P＜0.05),respectively,and the liver egg reduce rates were 58.6%,32.2%and 47.7%(P＜0.05),respectively,as compared with control group.The node densities on liver surfaces from treated groups were less than that from control mice.However,as compared the group administrated compounds 28-37 days after infection and the group administrated single pumpkin seeds 1-10 days after infection as well as the group administrated pumpkin seeds+ arecas with control group,threre was no difference in worm reduce rate and egg reduce rate.3:36 days after infection,two batches of animals were treated with single PZQ at the dose of 150mg/kg.d and 300mg/kg.d, respectively.The treatment effect with 35.8%-37.83%and 59.81%of worm reduce rates was not as well as what was predicted,respectively.It merits attention that the schistosomicidal effect of the mice administrated astragalus and then treated with PZQ was significantly enhanced.4:The experiment of in vitro killing schistosomulum of astragalus injection showed that the correct mortality rate was 24.1%in 24h and 22.0%in 48h.【Conclusion】Astragalus could produce a good effects of antischistosomulum. The influences of astragalus on immune response of host infected by schistosoma were showen through inhibition of production of antibody against egg antigen and hydroxyproline,as well as expression of IL-6 and inducing expression of IL-10.As to pumpkin seeds and arecas,there no significant killing effect could be found。...