Prevention of Schistosoma japonicum infection in mice with long-acting praziquantel implants.
This work reports the prevention outcomes of a praziquantel (PZQ) implant against the infection of Schistosoma japonicum in mice. The PZQ implant produced stable plasma PZQ concentrations in a range of 100-1300 ng/mL for a period of 70 days, by releasing PZQ in subcutaneous tissues in a sustained manner. To assess the prevention effects, the mice were infected at varying times after implantation. All the mice were sacrificed at 6 weeks after infection for worm and egg recovery and counting, worm morphological examination, determination of egg-hatching rates, and analysis of hepatic histology. The infection was successfully prevented for mice with early infection times (within 2-3 weeks), as nearly no worms, paired worms, eggs, or miracidia were recovered. However, in mice with late infection times (after 3 weeks), the prevention effects were diminished due to the decreased plasma PZQ concentrations at late times. Interestingly, the implants showed robust prevention effects on repeated infection at 1 and 3 weeks. In the infection-prevented mouse livers, no granuloma formation or granulomatous inflammation was observed. The results demonstrated that by blocking the development of infecting miracidia and by deactivating the eggs, the PZQ implants encouragingly prevented the S. japonicum infection and avoided liver damage.
School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China.
Lei
L
Lei
Liang
L
Cheng
Jingwen
J
Hou
Shengrong
S
Guo
Chuangang
C
Zhu
Yaojun
Y
Shi
Yan
Y
Jiang
Jiaojiao
J
Lin
D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage* / Q000097:blood; D004343:Drug Implants; D005260:Female; D008099:Liver / Q000469:parasitology / Q000473:pathology; D008297:Male; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011223:Praziquantel / Q000008:administration & dosage* / Q000097:blood; D011897:Random Allocation; D012549:Schistosoma japonicum / Q000187:drug effects / Q000648:ultrastructure; D012554:Schistosomiasis japonica / Q000517:prevention & control*; D013997:Time Factors
D000871:Anthelmintics; D004343:Drug Implants; D011223:Praziquantel