Peroxide antimalarials, including artemisinin, are important for the treatment of multidrug-resistant malaria. These peroxides are known to react with iron or heme to produce reactive intermediates that are thought to be responsible for their antimalarial activities. This study investigated the potential interaction of selected peroxide antimalarials with oxyhemoglobin, the most abundant form of iron in the human body. The observed stability of artemisinin derivatives and 1,2,4-trioxolanes in the presence of oxyhemoglobin was in contrast to previous reports in the literature. Spectroscopic analysis of hemoglobin found it to be unstable under the conditions used for previous studies, and it appears likely that the artemisinin reactivity reported in these studies may be attributed to free heme released by protein denaturation. The stability of peroxide antimalarials with intact oxyhemoglobin, and reactivity with free heme, may explain the selective toxicity of these antimalarials toward infected, but not healthy, erythrocytes.
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http://dx.doi.org/10.1128/AAC.00363-09 | DOI Listing |
Molecules
November 2024
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Agunmu (ground herbal medicine) is a form of West African traditional medicine consisting of a cocktail of herbs. The goal of this study is to evaluate a formulation of Agunmu made from , , , , and , sold in the open market and commonly used for the treatment of malaria by the locals, for its antimalarial effects and to determine the active principles that may contribute to the antimalarial effect. The ethanolic extract obtained from this formulation (Ag-Iba) was analyzed, using TLC, LC-MS, and Tandem-MS techniques, to determine its phytochemical properties.
View Article and Find Full Text PDFACS Infect Dis
January 2025
Laboratoire de Chimie de Coordination du CNRS, LCC-CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France.
The 1,2,4-trioxolane antimalarial drug, OZ439 (artefenomel), exhibits cross-resistance to artemisinins with similar survival rates of artemisinin-resistant parasites after dihydroartemisinin or OZ439 exposure, suggesting that this drug shares some mechanisms of action with artemisinins. In this way, we investigated the reductive activation of OZ439 by heme in the presence of dithionite, demonstrating the formation of covalent heme-drug adducts. However, in the presence of the biologically abundant reductant glutathione instead of dithionite, heme-drug adducts were not detected, contrary to artemisinin that efficiently alkylates heme regardless of the reductant used.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
Key Laboratory of Photochemical Biomaterials and Energy Storage Materials, Heilongjiang Province and College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025, China. Electronic address:
This study addresses the challenge of enhancing ferroptosis efficacy for tumor therapy, particularly the limited therapeutic efficiency of current inducers due to tumor microenvironment constraints. Herein, we developed a hollow ultrasound-triggered ZnFeO-BiMoO (ZB) S-scheme heterojunction loaded with artesunate (ART) to overcome these limitations. The ZB heterojunction with a particle size of ∼250 nm efficiently separates electron-hole pairs under ultrasound (US), promoting the generation of reactive oxygen species (ROS).
View Article and Find Full Text PDFBMC Med
November 2024
QIMR Berghofer Medical Research Institute, Brisbane, Australia.
Background: The combination antimalarial artefenomel-piperaquine failed to achieve target efficacy in a phase 2b study in Africa and Vietnam. We retrospectively evaluated whether characterizing the pharmacological interaction of this antimalarial combination in a volunteer infection study (VIS) would have enabled prediction of the phase 2b study results.
Methods: Twenty-four healthy adults enrolled over three consecutive cohorts were inoculated with Plasmodium falciparum-infected erythrocytes on day 0.
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