Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 17 1 2022 03 14 53 61 Hajar Mikaeiloo Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Fatemeh Ghaffarifar Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Abdolhossein Dalimi Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Mohammad Zuhair Hassan Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University of Medical Sciences, Tehran, Iran Zohreh Sharifi Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran 2020 12 13 2021 07 07 Background: Toxoplasma gondii is an obligate intracellular parasite that can infect humans and animals. As the choice drug have shown side effects, development a new drug with low toxicity will be necessary. Methods: BALB/c mice were infected with tachyzoiets of T. gondii. After treatment by oral and parenteral artemether (250 µg/mice) and sulfadiazine (50 µg/mice), we evaluated the rates of survival in treated and control mice. The fold change of B1 gene (target gene) expression in liver and brain of mice treated with parenteral artemether (i.p.), oral artemether (via gavage) and sulfadiazine, were detected by using the Real-Time quantitative PCR. Results: Both treatment with sulfadiazine and artemether showed significant prolongation in time to death of the infected mice compared to the control group. Median survival days for parenteral artemether, oral artemether, sulfadiazine and control group were 8, 11, 12 and 6 d respectively. Expression of B1 gene in liver and brain of mice after treatment with artemether and sulfadiazine were reduced in comparison to housekeeping gene (β-tubulin gene). The fold change (comparing to control group) for parenteral artemether, oral artemether, sulfadiazine is 0.034, 0.027 and 0.111 for liver and 0.220, 0.425 and 0.366 for brain respectively. Conclusion: Artemether is effective to control the tachyzoites of T. godii in vivo conditions and oral treatment is more effective than parenteral treatment. Due to its low cytotoxicity and its high effective action against the tachyzoietes of T. godii in susceptible animals. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3201 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3201/1195