Evaluation of the Combined Effect of Artemisinin and Ferroptosis Inducer RSL3 against .

is a widespread intracellular pathogen that infects humans and a variety of animals. Dihydroartemisinin (DHA), an effective anti-malarial drug, has potential anti- activity that induces ferroptosis in tumor cells, but the mechanism by which it kills is not fully understood. In this study, the mechanism of DHA inhibiting growth and its possible drug combinations are described. DHA potently inhibited with a half-maximal effective concentration (EC) of 0.22 μM. DHA significantly increased the ROS level of parasites and decreased the mitochondrial membrane potential, which could be reversed by ferroptosis inhibitors (DFO). Moreover, the ferroptosis inducer RSL3 inhibited with an EC of 0.75 μM. In addition, RSL3 enhanced the DHA-induced ROS level, and the combination of DHA and RSL3 significantly increased the anti- effect as compared to DHA alone. In summary, we found that DHA-induced ROS accumulation in tachyzoites may be an important cause of growth inhibition. Furthermore, we found that the combination of DHA and RSL3 may be an alternative to toxoplasmosis. These results will provide a new strategy for anti- drug screening and clinical medication guidance.