Effect of calcium channel blockers and actin depolymerizing/stabilizing agents on the survival of Schistosoma japonicum treated with praziquantel in vitro / 中国人兽共患病学报

ABSTRACT

To explore the action target of praziquantel (PZQ) and its underlying mechanism of action, adult male worms of Schistosoma japonicum were collected from the hepatic vein of Kunming mice infected at least 6 or more weeks previously with single-sex cercariae of S.japonicum by perfusion method. These worms were subjected to the action of calcium channel blockers (CCBs) or actin depolymerizing/stabilizing agents interfering with function of the calcium channel. The adult male worms in DMEM culture medium were co-cultivated with near-lethal dose of PZQ(14 μmol/L) overnight(16 hours).Then, the parasites were washed 3 times with sterile physiologic saline next morning after cultivation, re-suspended in new and drug-free medium and then observed under stereo-microscopy during the following 5 days. The experimental results showed that majority of adult male worms of S.japonicum were killed by the action of PZQ in a dose of 14 μmol/L in vitro under normal condition; while the worms pre-incubated with the actin depolymerizing agent cyto chalasin D (CyD) were able to survive in the condition containing 14 μmol/L of PZQ with a survival rate of 100%, and the worms pre-incubted with CCBs, such as nitrendipine and nifedipineu showed a survival rate of about 50% under the same condition. The results of this study suggest that the calcium channel of Schistosomes may be involved in the action target of PZQ and its underlying mechanism.