Anti-Toxoplasma Activity of 2-(Naphthalene-2-γlthiol)-1H Indole

BACKGROUND This study was undertaken to evaluate the viability, infectivity and immunity of Toxoplasma gondii tachyzoites exposed to 2-(naphthalene-2-ylthio)-1H-indole. METHODS Tachyzoites of RH strain were incubated in various concentrations of 2-(naphthalene-2-ylthio)-1H-indole (25-800 μM) for 1.5 hours. Then, they were stained by PI and analyzed by Fluorescence-activated cell sorting (FACS). To evaluate the infectivity, the tachyzoites exposed to the different concentrations of the compound were inoculated to 10 BALB/c mice groups. For Control, parasites exposed to DMSO (0.2% v/v) were also intraperitoneally inoculated into two groups of mice. The immunity of the exposed tachyzoites was evaluated by inoculation of the naïve parasite to the survived mice. RESULTS The LD50 of 2-(naphthalene-2-ylthio)-1H-indole was 57 μmol. The longevity of mice was dose dependent. Five mice out of group 400μmol and 3 out of group 800μmol showed immunization to the parasite. CONCLUSION Our findings demonstrated the toxoplasmocidal activity of the compound. The presence of a well-organized transporter mechanism for indole compounds within the parasite in conjunction with several effective mechanisms of these compounds on Toxoplasma viability would open a window for production of new drugs and vaccines.