Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 10 4 2015 12 14 577 583 EN Zaid O IBRAHEEM Pharmacology Unit, Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia Roslaini ABDUL MAJID Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia Sabariah MOHD NOOR Department of Hematology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia Hasidah MOHD SIDEK School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM-Bangi, Selangor, Malaysia Rusliza BASIR Pharmacology Unit, Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2015 12 14 2015 12 14 Background: Nowadays, scourge of malaria as a fatalistic disease has increased due to emergence of drug resistance and tolerance among different strains of Plasmodium falciparum. Emergence of chloroquine (CQ) resistance has worsened the calamity as CQ is still considered the most efficient, safe and cost effective drug among other antimalarials. This urged the scientists to search for other alternatives or sensitizers that may be able to augment CQ action and reverse its resistance. Method: Three β-carbolin derivatives, namely, harmalin, harmol and harmalol were tested for their anti-plasmodial and CQ resistance reversal effects against P. falciparum 3D7 and K1. SYBRE Green-1 based drug sensitivity assay and isobologram analysis were used to screen the mentioned effects respectively. Results: All of them showed moderate anti-plasmodium effect and harmalin was the most effective as compared to the others in reversing CQ resistance and tolerance. Conclusion: The mentioned phytochemicals are not ideal to be used as conven­tional anti-malarials and only harmalin can be suggested to reverse CQ resistance in P. falciparum K1. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/657 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/657/538