Effect of nitaxozanide and pyrimethamine on astrocytes infected by Toxoplasma gondii in vitro.

BACKGROUND AND AIMS

T. gondii is a causal agent of encephalitis in immunocompromised patients. Pyrimethamine (PYR) has been the treatment of choice for toxoplasmosis. The aim of this study was to analyze the effect of nitazoxanide and pyrimethamine on astrocytes infected with T. gondii in vitro.

METHODS

Rat astrocytes were cultured and infected with T. gondii. The effect of nitazoxanide (10, 20 and 30 μg/mL) and pyrimethamine (7, 10 and 13 μg/mL) on astrocytes infected was evaluated at 24 and 48 h post-infection. Tachyzoites and astrocytes were detected by the immunocytochemical method. T. gondii viability in astrocytes infected and treated with NTZ and PYR as well as NTZ and PYR cytotoxicity on astrocytes in vitro were evaluated by the MTT assay.

RESULTS

The number of parasites in astrocytes treated with the drugs was significantly reduced when compared to control (p <0.001) at 24 and 48 h. Nitazoxanide produced 97% T. gondii death in a concentration of 10 μg/mL in 48 h infected astrocytes. At 48 h, the death rate of T. gondii was higher when treated with nitazoxanide than with pyrimethamine. A higher toxicity rate in astrocyte was observed when using pyrimethamine at 40 μg/mL.

CONCLUSIONS

Nitazoxanide reduced T. gondii infection more efficiently than pyrimethamine and is not cytotoxic to astrocytes at the administered dose.