Objective: This study was undertaken to evaluate the effect of titanium dioxide (TiO2)
nanoparticles (NPs) and methanolic extract of Persian Gulf brown algae (Sargassum oligocystum)
on the growth and cell death of T. gondii tachyzoites in vitro and in vivo.
Methods: Six- to eight-week-old female BALB/c mice (n = 28) were used for the treatment experiment
and infected with 105 T. gondii tachyzoites. Four days after treatment, IFN-γ and the levels of
splenic lymphocyte proliferation were measured. All the groups were challenged with T. gondii,
and the survival rate of experimental mice was assessed. The effects of TiO2NPs and S. oligocystum
on the proliferation of T. gondii were evaluated by MTT and annexin V staining in vitro.
Results: Based on the results, the combination of S. oligocystum extract and TiO2NPs exhibited a
more cytotoxic effect compared to their use separately. The results of the challenge test also revealed
that mice which received combined treatment had the highest life time expectancy than
those receiving the treatment alone.
Conclusion: The simultaneous use of immunomodulatory compounds for the stimulation of the immune
system as well as S. oligocystum and TiO2NPs with antiparasitic activity can be promising to
develop an effective drug for the treatment of toxoplasmosis.