Effect of artesunate on Toxoplasma gondii: in vitro and in vivo studies

The effect of Artesunate (As) on Toxoplasma gondii (T. gondii) in vitro and in vivo was studied. In vitro, tachyzoites of RH strain were exposed to As in a concentration of 2 microg/ml for 72 hours. The assessment of As effect was carried out by studying the viability, infectivity and ultrastructure changes of treated tachyzoites by scanning electron microscope (SEM). In the in vivo study, Swiss albino mice were infected intraperitoneally with tachyzoites of T. gondii RH strain, then orally treated with As in a dose of 200 mg/kg for five successive days. The effect of As was evaluated by the mortality rate and survival time of the treated mice. Parasite burden, viability, infectivity and ultrastructure changes of tachyzoites harvested from the peritoneal cavities of infected treated mice as compared with infected non-treated control mice were also studied. In vitro study demonstrated a significant reduction in viability and infectivity of tachyzoites exposed to As compared with untreated controls. In vivo study, showed that treatment of infected mice with As induced a significant decrease in mortality rate and increase in survival time. There was also a significant reduction in parasite burden in infected treated mice with significant reduction in viability and infectivity of tachyzoites harvested from them as compared with infected non-treated control. SEM showed distortion in tachyzoites' shape, peeling, erosions and discontinuity in areas of surface membrane of treated tachyzoites of both in vitro and in vivo studies. So, As proved an effective and promising drug in treating acute toxoplasmosis.