ORIGINAL ARTICLE Histopathologic study on mice infected with Plasmodium berghei after treatment with sulfadoxine-pyrimethamine, pyrimethamine, and hydroxychloroquine sulfate Mohammad Reza Vafaei 1 & Hamed Kalani 1 & Nader Pestehchian 1 & Pardis Nematolahi 2 Received: 5 June 2017 /Accepted: 19 September 2017 /Published online: 26 September 2017 # Springer-Verlag London Ltd. 2017 Abstract Malaria, a disease caused by a parasitic protozoan belonging to the genus Plasmodium spp., is one of the com- mon diseases in the tropical regions. Our aim in this study is to examine the effects of sulfadoxine-pyrimethamine, pyrimeth- amine, and hydroxychloroquine sulfate on the liver, spleen, and kidneys of treated mice with Plasmodium berghei. Mice were divided into five groups, of which three were infected with the parasite and treated with the aforementioned drugs. The other two groups were considered as negative (non- infected) and positive (infected) controls. The histopathologi- cal changes in the spleen among the different groups were observed and the highest change was in the pyrimethamine group. Prescribing these medications are necessary, especially for people who take these drugs in the long term, since these drugs may cause severe adverse effects. Keywords Sulfadoxine-pyrimethamine . Plasmodium berghei . Pyrimethamine . Hydroxychloroquine sulfate Introduction Malaria, a disease caused by a parasitic protozoan belonging to the genus Plasmodium spp., is one of the common diseases in the tropical regions. Almost half of the world’ s population is at risk of the disease. About 200 million people are already infected with the disease (Organization WH 2014). Malaria pathogenesis is dependent on the parasite growth, prolifera- tion, and the potency of host immune responses (Reisinger et al. 2005). The malaria disease manifestations are mostly ague, sweating, and anemia and occasional cerebral symp- toms, splenomegaly, and kidney problems may happen (Olsson and Johnston 1969). Animal models for studying ma- laria are useful because there are limitations on the nature and interpretation of in vitro studies, particularly with regard to the behavior of host immune cells and the use of animal models to understand the pathogenesis of disease .Moreover, these models have been used for pre-clinical testing of various drugs and vaccines (Sanni et al. 2002). Plasmodium berghei has specific morphology and red blood cell (RBC) tropisms are used as experimental models for human disease (Schofield and Grau 2005) Cinchona bark is the most commonly used natural medicine against malaria. Raw material for the produc- tion of quinine is extracted from the bark of this plant (Kyle and Shampe 1974). In recent years, many reports have been recorded about the development of drug resistance to some Plasmodium spp., especially in endemic areas (Pattanasin et al. 2003). Several medications are used to treat malaria, including chloroquine, pyrimethamine, and sulfadoxine-pyri- methamine. Chloroquine has been used for decades as an ef- fective medication and is low-cost and readily available. Nevertheless, the use of chloroquine has been limited due to the emergence of strains resistant to this drug (Neequaye et al. 1986; Peters 1998). However, chloroquine is still used as first line of treatment even in malaria-endemic countries. Today, the use of combinational therapy and artemisinin derivatives has created new hope for the fight against malaria and is the new challenge for chemotherapy (Harinasuta and Karbwang 1994; Hien 1994). Sulfadoxine-pyrimethamine is one of the alternative drugs that can be used for chloroquine-resistant malaria. Today, a serious problem in terms of the fight against * Pardis Nematolahi nematolahy@yahoo.com 1 Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 2 Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Comp Clin Pathol (2018) 27:123–129 DOI 10.1007/s00580-017-2563-7