Flubendazole fbz

Flubendazole (FBZ) (cat# 34091) and oxfendazole (OFZ) (cat# 34176) were obtained from Sigma-Aldrich (Germany). Both drugs were administered subcutaneously, with FBZ given at a dose of 10 mg/kg body weight, SID, and OFZ given at 12 mg/kg body weight, BID, for 5 days starting 3 days post-implantation. The vehicle used for both drugs was composed of 0.5% HEC (hydroxyethyl cellulose), 0.1% Tween 80, and 99.4% water.

The life cycle of L. sigmodontis was maintained in their natural reservoir, the cotton rats (Sigmodon hispidus). Therefore, cotton rats were anesthetized by isoflurane narcosis and blood was collected from the retro-bulbar sinus in order to count the microfilariae (MF, L1). Cotton rats, which were used for further infection of blood-sucking mites (Ornithonyssus bacoti), had an infection rate of 500 – 2000 MF per µl blood. Infected cotton rates were exposed to mites that ingested MF during a blood meal. Infected mites were kept at 29°C and 90% humidity for 14 days to allow maturation of L1 to L3. Experimental mice were anesthetized with ketamine/xylazine (100 mg and 5 mg/kg body weight) and exposed to these infected mites for 16 hours, i.e., naturally infected. To quantify the worm load, infected mice were sacrificed at indicated time points and the thoracic cavity was flushed with 10 mL PBS. Viable worms were defined by movement. Coated worms were defined as worms either moving or immobile that were covered with host cells. By contrast, dead worms were free of visible host cells and did not move anymore. The anthelminthic drug flubendazole (FBZ, Sigma, Germany) was administered by repeated s.c. injection on 5 consecutive days with a dose of 5 mg/kg body weight.