Evaluating The Therapeutic Effect of 2-Nitroimidazole on <i>Toxoplasma gondii</i>: An In vitro and In vivo Study Using BALB/c Mice

Background: Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, remains a significant health concern due to its widespread prevalence and severe impact on immunocompromised individuals. Current treatments are limited, necessitating the exploration of new therapeutic agents. Objectives: This study aimed to evaluate the efficacy and safety of 2-nitroimidazole as a potential treatment for toxoplasmosis in BALB/c mice, comparing its effects with the standard treatment, sulfadiazine. Methods: In vitro assays were conducted to determine the half-maximal inhibitory concentration (IC50) of 2-nitroimidazole and sulfadiazine against T. gondii tachyzoites. The MTT assay was used to assess the cytotoxicity of 2-nitroimidazole on macrophages. In vivo experiments involved treating BALB/c mice infected with T. gondii with either 2-nitroimidazole or sulfadiazine, monitoring survival rates and therapeutic outcomes. Results: In vitro results revealed IC50 values of 5.43 μM for 2-nitroimidazole and 2.99 μM for sulfadiazine, indicating potent anti-tachyzoite activity. The MTT assay showed that 2-nitroimidazole had low cytotoxicity, with significant cell viability even at higher concentrations. Based on the MTT assay findings, 40 μM of 2-nitroimidazole showed the highest level of toxicity towards macrophages. Furthermore, flow cytometry analysis revealed that this compound induced apoptosis in approximately 58.9% of tachyzoites. In vivo, all mice in the control group died by the eighth day. Treatment with sulfadiazine resulted in two mice surviving until the 14th day, while 2-nitroimidazole treatment saw one mouse surviving to the same day. These findings suggest that 2-nitroimidazole has comparable efficacy to sulfadiazine with potentially fewer side effects. Conclusions: The study demonstrates that 2-nitroimidazole is a promising candidate for the treatment of toxoplasmosis, exhibiting strong anti-parasitic activity and low cytotoxicity. Further research is warranted to optimize dosing regimens and explore combination therapies to enhance its therapeutic potential.