Nigella sativa loaded PLGA nanoparticles effect on murine schistosomiasis mansoni: Worm burden and tegumental ultrastructure

Background: Currently, the treatment of schistosomiasis depends on praziquantel (PZQ). Nigella sativa oil (NSO) is a promising herbal medicine with anti-schistosomal effects. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles can be used as a drug delivery vehicle. Objective: To evaluate the effect of NSO alone, loaded on PLGA nanoparticles, and combined with PZQ, on murine schistosomiasis. Material and Methods: Forty-eight Swiss albino mice were equally divided into six groups. Control negative group: not infected mice and not treated; control positive group: infected and not treated; NS group: treated with NSO only; NP 1 group: full dose treated by NSO/PLGANPs; NP 2 group: half dose treated with NSO/PLGANPs NPP group: half dose treated with NSO/PLGANPs and PZQ. Mice were sacrificed 9 weeks post-infection (wpi) and porto-mesenteric perfusion was performed for recovery of adult worms. The reduction in worm burden in different groups was calculated. Scanning electron microscopic (SEM) tegumental examination of adults was performed. Results: The NPP group revealed the highest reduction (100%) in total adult worm burden; in males mean number and couples. The NP1 group followed with reductions of 68.14%, 74.8% and 67.47%, respectively. Tegumental examination of adult worms in NP1 group showed severe destruction of males' and females’ tegument with severe peeling. There were constrictions in the body of females and blebbing and erosions with vesicle formation in males' and females’ tegument. Although 100% reduction of worms was recorded with NPP treatment, SEM changes were more severe with NPI treatment. Conclusion: It was concluded that PLGANPs potentiated the therapeutic effect of NSO, and promoted the PZQ schistosomicidal effect. It induced a highly significant reduction in parasitic worm burden and markedly affected the ultrastructure of retrieved adult worms.