Viability and infectivity of Toxoplasma gondii tachyzoites exposed to Butanedione monoxime.

Abstract

The most important pathogenesis factor in the Apicomplexa parasites is invasion to the host cell. Given the inhibitory role of Butanedione Monoxime (BDM) on myosin–actin interaction, this study aimed to investigate the effects of this molecule on the vitality and infectivity of Toxoplasma tachyzoites in order to provide a new option for vaccine development. The tachyzoites of the RH strain of Toxoplasma gondii were exposed to different concentrations (1, 2, 4, 8, 16, 32, 64, and 128 μg/mL) of BDM, and mortality effect was assessed by flow cytometry. Then, the penetration ability of the tachyzoites was investigated in HeLa and macrophage cell lines. The infectivity of exposed tachyzoites to BDM were also investigated in mice through following up and detecting the etiological factor. The highest percentage of mortality (72.69%) was seen in the tachyzoites exposed to 128 μg/mL of the compound. The tachyzoites exposed to 32, 64, and 128 μg/mL of BDM began the proliferation in HeLa cells after 48 h, while this proliferation was initiated within 24 h in macrophage cells. All the mice inoculated with the BDM-treated tachyzoites died after 13 days. The mean survival time of the mice receiving tachyzoites exposed to 128 μg/mL of BDM was 12.4 days, which was significantly different from the negative control group (p = 0.001). BDM, as the inhibitor of myosin–actin interaction, and other substances that block the entry of parasites into cells may be suitable candidates for vaccine production against Toxoplasma. Yet, future studies are required to be conducted on the issue.