Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 14 4 2019 12 29 542 551 EN Farzaneh MIRZAEI Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Hossein KHANAHMAD Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Fatemeh NAMDAR Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Teh-ran, Iran Shahrokh IZADI Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Teh-ran, Iran Seyed Hossein HEJAZI Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran AND Skin Diseases and Leishmaniasis Research Center, Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 2016 12 20 2019 12 29 Background: We aimed to design a different method of drug delivery for increased transfer of the choice drug (meglumine antimoniate) within the host cells. Therefore, listeriolysin O (LLO), a bacterial product which is a member of pore-forming peptides was used as an enhancer factor with meglumine antimoniate in order to facilitate the transition of the drug across macrophage membrane. Methods: LLO was produced in Isfahan University of Medical Sciences in 2016, by expressing the hlyA gene in Escherichia coli and purified using affinity chromatography. Cytotoxicity of the purified protein was investigated in an in vitro model of macrophage Leishmania infection. Results: LLO was cytotoxic against murine macrophage cells (J774-A1) and amastigote forms of L. major (MRHO/IR/75/ER). It was less toxic to macrophages (CC50=2.56 μg ml-1 ±0.09) than to the parasites (IC50=1.72 μg ml-1 ±0.07). Moreover, non-cytotoxic concentration of LLO (0.006 ug ml-1) potentiated the cytotoxicity induced by low dose concentration of meglumine antimoniate. Very little dose of meglumine antimoniate was needed when combined with the LLO (IC50=12.63 μg ml-1 ±0.13) in comparison with the cytotoxicity induced when the drug is used alone (IC50=46.17 μg ml-1 ±0.28). Conclusion: The combination of pore-forming proteins with anti-leishmanial agents could increase the advantage of anti-leishmanial drugs. Since lower concentrations of anti-leishmanial drugs can reduce undesirable side effects of chemotherapy trials carried out in animal models and then in humans with this system. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1339