The inhibitory effect of cromolyn sodium and ketotifen on Toxoplasma gondii entrance into host cells in vitro and in vivo.

Toxoplasma gondii is a protozoan with worldwide distribution and in spite of increasing information about its biology, treatment of toxoplasmosis is restricted to a few drugs and unfortunately using of each of drugs is associated with significant side effects in patients. This study was designed to evaluate the efficacy of cromolyn sodium and ketotifen as alternative drugs for the treatment of toxoplasmosis. In vitro; in case group, concentrations of 1, 5, 10 and 15 µg/ml of ketotifen and cromolyn sodium were added to RPMI medium containing peritoneal macrophages. After 1 h incubation and adding tachyzoites to medium, efficacy rate of these drugs in entrance inhibition of Toxoplasma tachyzoites into macrophages were evaluated after 30 and 60 min. In vivo; case groups received ketotifen and cromolyn sodium with different concentrations at various times. Control groups received none of drugs. We found that in vitro; after 60 min the best efficacy of these drugs in inhibition of cell entrance of Toxoplasma was observed at 15 µg/ml (78.9 ± 1.70 and 91.97 ± 0.37 %, respectively) (P < 0.05). In vivo; after 60 min ketotifen at 2 mg/kg in 3 h before tachyzoite injection (69.83 ± 2.25 %), and cromolyn sodium, at 10 mg/kg in 6 h before tachyzoite injection (80.47 ± 2/49 %) had the best effect on inhibition of Toxoplasma entry into the cells (P < 0.05). Our findings show that ketotifen and cromolyn sodium are suitable drugs for entrance inhibition of tachyzoites into nucleated cells in vitro and in vivo.