Effect of co-trimaxazole on REP-529 and TNF-α transcription levels in the brain of Toxoplasma gondii infected-mice

Toxoplasmosis is a globally prevalent parasitic infection caused by Toxoplasma gondii. A flu-like syndrome is seen in the acute phase of infection with no obvious symptoms in the chronic phase. In this study effect of co-trimaxazole on parasite load and inflammation in the brain of infected mice was examined.

Mice were infected by intraperitoneal injection T. gondii cysts. Transcription of REP-529 (as indicator of parasite load) and TNF-α (as indicator of inflammation) were measured in the mice brain by RT-qPCR, at weeks 1-8 after injection of cysts, and after treatment with co-trimoxazole. Co-trimoxazole was administered 10 days before the weeks 4 and 8 of the infection for 10 days.

Severe ascites was observed during 4-14 days after injection of cysts. The REP-529 transcription level indicates that the parasite enters the brain 1 week after cyst injection and proliferated rapidly in the second and third weeks. TNF-α level increased and reached the maximum level in the second week and then decreased in the next weeks. Co-trimoxazole significantly reduced transcription of both REP-529 and TNF-α during 4 and 8 weeks of infection. Co-trimoxazole caused significant (p < 0.01) weight gain in mice at the week 4 of infection compared to the untreated group.

We found chronic administration of co-trimoxazole to mice infected by T. gondii can inhibit parasite proliferation and inflammation in the brain and cure the disease.