Activity Evaluation and Mode of Action of ICA Against Toxoplasma gondii In Vitro

Toxoplasmosis is a significant zoonotic parasitic disease. Currently, there is no effective vaccine available to prevent human Infection, and treatment primarily relies on chemotherapy. However, the lack of specific therapeutic agents and the limitations of existing drugs highlight the urgent need for novel, safe, and effective anti-Toxoplasma gondii (T. gondii) medications. In this study, we evaluated the toxicity of ICA (N-(pyridin-2-yl)-4-(pyridine-2-yl)thiazol-2-amine) to host cells and assessed its inhibitory and anti-proliferative effects on T. gondii tachyzoites. We further investigated the impact of ICA on the ultrastructure of T. gondii using transmission electron microscopy (TEM). Additionally, we measured alterations in mitochondrial membrane potential, superoxide levels, and ATP levels in T. gondii to assess the effect of ICA on mitochondrial function. Our findings demonstrated that ICA exhibits a safe and effective inhibitory effect on T. gondii, with a selectivity index (SI) of 258.25. Notably, ICA demonstrated a more potent anti-proliferative effect than pyrimethamine (PYR). Ultrastructural observations revealed that ICA induces mitochondrial swelling and membrane rupture in T. gondii. Further investigations confirmed that ICA leads to mitochondrial dysfunction in T. gondii. In conclusion, our results suggest that ICA possesses the potential to serve as a lead compound for the development of novel anti-T. gondii therapies.

ICA; Toxoplasma gondii; mitochondria; ultrastructure.