Improve Praziquantel Killing Method

Objective : To explore the drugs or methods for improving the schistosomicidal effect of PZQ.Methods : Two Chinese herbal preparations were selected as immunoenhancing agents. Polyclonal antisera and monoclonal antibodies against surface membrance antigens of adult Sj were produced. The schistosomicidal effect of praziquantel combined with immunoenhancer was observed. The mechanism of improving schistosomicidal effect was analyzed by ELISA, IFA and immunopathological examinations. The immunological characteristics of Sj surface membrance antigen, polyclonal antisera and monoclonal antibodies were characterized by SDS-PAGE and Western-blot.Results : 1. The schistosomicidal effect of praziquantel were increased by combing two Chinese herb compounds by 33.97% and 41.18%, respectively. But liver granulomas lession wasn't increased. The comparison of antibody levels in different groups suggested that Chinese herbal preparations enhance the specific antibody production. 2. Worm burden and egg burden of mice treated by immune serum plus praziquantel were dramatically reduced , compared with those of the mice treated with PZQ alone. The immune serum increased the schistosomicidal effect of PZQ against different developmental stages (2d,14d and 35d) by 38.79%, 29.80% and 46.82%, respectively . Egg burden in liver was decreased by 62.04%, 42.78% and 29.81%, respectively. The result of Western-blot indicated that the immune serum against SjAWMAg can cross-react with the antigens of the lung and liver schistosomula. 3.Three hybridoma cell strains secreting SjAWMMcAbs were established. The type of the McAbs are all IgG. These McAbs recongnized 5 target antigens (Mr Wt. 28,31,32,38 and 82 kDa). The three McAbs reacted specifically with surface membrane of adult Schistosoma japonicum by IFA. Among them two McAbs combined with PZQ can improve the schistosomicidal effect.Conclusions : 1. The two Chinese herb compounds selected can improve the effect of praziquantel in killing Schistosoma japonicum. These may be related to that the herbs can improve the host immune response, especially enhance the specific antibody production. 2.The polyclonal antisera and monoclonal antibody against SjAWMAg combined with PZQ can improve theschistosomicidal effect. The polyclonal antisera can also improve the effect of PZQ in killing different developmental schistosomula. All these indicated that the humoral immunity play a key role in the schistosomicidal process of PZQ.