Methodological investigation of cyclophosphamide-induced immunocompro-mised mice model and effect of extract of Rosa laevigata Michx.combined with probiotics on immune function
Objective:To establish a mice model that is more in line with the human immunocompromised state,and to inves-tigate the regulatory effect of Rosa laevigata Michx.,probiotics and their combination on their immune function.Methods:Immunosup-pressive model of mice was established by using cyclophosphamide with different dosage,time and end point,and compared with im-munosuppressive model induced by hydrocortisone and cyclosporine A,immunosuppressive model of mice was established by injecting 25 mg/kg cyclophosphamide 7 times every other day,without recovery period;changes in the proportion of lymphocytes in spleen(CD4+T cells,CD8+T cells,CD19+B cells)were analyzed by flow cytometry;qRT-PCR was used to detect expression levels of inflam-matory factors(IL-1β and IL-6)mRNA in spleen.Results:After continuous injection of 80 mg/kg cyclophosphamide for 3 days,the thymus was atrophied,the spleen was significantly swelling,proportion of immune cells CD4+T cells,CD8+T cells and CD19+B cells in spleen were significantly decreased,while mRNA expressions of IL-1β and IL-6 were up-regulated.After 7 injections of 25 mg/kg cyclophosphamide every other day,the thymus and the spleen were significantly atrophied,proportion of CD4+T cells and CD8+T cells in spleen showed an increasing trend,and mRNA expressions of IL-1β and IL-6 were up-regulated;after 1 week or 2 weeks recovery period from cyclophosphamide injection,weight and index of immune organs,proportion of spleen lymphocytes and mRNA expres-sions of inflammatory cytokines in spleen were significantly reversed;Rosa laevigata Michx.combined with probiotics could signifi-cantly reverse the up-regulation of CD4+T cells and inflammatory factor IL-1β caused by cyclophosphamide.Conclusion:In this study,an immunocompromised mice model has been established with 7 injections of 25 mg/kg cyclophosphamide every other day and without recovery period.And a certain positive immunomodulatory effect of the combination of Rosa laevigata Michx.and probiotics has been found.