Experimental Study Of Fructus Psoraleae And Dihydroarteminsinine In Treating Mice With Cryptosporidiosis

Background : Cryptosporidium species are intracellular protozoan parasites, which are important oppotunistic protozoans and can cause cryptosporidiosis. There are 2 kinds of Cryptosporidium that can cause human infection:Cryptosporidium parvum (C.parvum) and Cryptosporidium hominis (C.hominis). C.hominis spreads among humans,but C.parvum spreads not only among humans but also among mammals. Humans and animals are infected through ingesting these oocysts. In immunocompetent subjects,the disease most commonly presents as an acute, selflimited but often persistent enterocolitis. However, in immunocompromised and immunosuppressed individuals, particularly those infected with the human immunodeficiency virus, infants, aged people, patients receiving immuno- suppressant, tumor patients receiving radiotherapy and chemotherapy and congenital T, B cell deficient patients, Cryptosporidium infection may be insidious in onset and may progress to a chronic and life-threatening disease resulting in multisystem involvement and mortality. At present, Crypto- sporidium is a necessary inspection item of AIDS patients.Cryptosporidium infection is closely related to hosts'immunity, including cellular and humoral immunity. The former, especially CD4~+T cell, is very important in controlling Cryptosporidium infection. There are many reports about cryptosporidiosis, such as pathogenisis, molecular biology, immunology and drug therapy, but a few are about the role of traditional Chinese medicine in regulating hosts'immunity and killing Cryptosporidium. Fructus Psoraleae can regulate hosts'immunity and Dihydroarteminsinine can kill parasites, but there are no reports about the effects of the mixture of the two drugs on cryptosporidiosis. The mixture was used to treat mice cryptosporidiosis in this experiment.Objective: To explore the immune regulation effect of Fructus Psoraleae and Dihydroarteminsinine on mice Cryptosporidiosis.Materials and methods: Healthy and male Kunming mice weighing 30-35g were randomly divided into 3 groups. Normal control group received common tap water as controls. Infected control group received drinking water mixed with dexamethasone (11.25mg/ml) and glucose (50g/L) in it for 5 days. Their feces are centrifuged and the precipitation were smeared and stained with modified acid fast stain. C.parvum was found, which suggested that mice Cryptosporidiosis model was established. Therapeutic group were treated with Fructus Psoraleae and Dihydroarteminsinine for 1 week (including Fructus Psoraleae3.4g/kg and Dihydroarteminsinine60mg/kg/d) after mice Cryptosporidiosis model was established. Blood CD4~+T and CD3~+T lymphocyte proportion was analyzed by using flow cytometry. Serum IFN-gamma (IFN-γ) was detected by using sandwich ELISA and nitric oxide (NO) in small intestine tissue of each group were assayed by using spectrophotometer 721.A part of ileum of each group was made into histological section and subjected to HE staining. Another part was made into ultrathin section and observed under electron microscope (EM). Values were expressed as x±s and the difference significance between mean values was analyzed by one-way analysis of variance (ANOVA) followed by the Duncan test for multiple comparison which uses Statistical Package for Social Sciences 12.0 (SPSS 12.0) computer package. The P values smaller than 0.05 were selected to indicate statistical significance between groups.Results:(1) CD4~+T,CD3~+Tlymphocyte proportion and Serum IFN-γconcentration of infected control group are significantly lower than those of normal control group(P<0.05). Those results of therapeutic group are significantly elevated comparing with infective control group (P<0.01). (2) NO level in small intestine tissue in infective control group is significantly higher than that in normal control group (P<0.05).The level of therapeutic group is much higher than that of both normal and infective control group (P<0.01.) (3) The oocysts number of therapeutic group is obviously less than that of infective control group (P<0.05).The number reduction rate is 57.9%. (4) The extent of damage to ileum in therapeutic group is less than that of infective control group under LM and EM.Conclusions: 1. Cryptosporidium species can cause cryptosporidiosis and destroy/ inhibit the hosts'immune function, especially reduce CD4~+T lymphocyte number. 2.The test indicates that Fructus psoraleae and Dihydroarteminsinine can kill Cryptosporidium parvum and treat mice Cryptosporidiosis through regulating mice immunity including elevating serum IFN-γ,blood CD4~+Tcell and CD3+Tcell proportion and small intestine tissue NO.