Chemical investigation of the antimalarial medicinal plant led to the isolation of five new diterpenoids, including ajugarins VII-X (-) and teuvincenone K (), along with four known compounds, namely, 12,16-epoxy-6,11,14,17-tetrahydroxy-17(15 → 16)--5,8,11,13,15-abietapentaen-7-one (), methyl pheophorbide A (), loliolide (), and acacetin (). The chemical structures of the new compounds were elucidated using NMR spectroscopy, mass spectrometry, circular dichroism, as well as density functional theory calculations. All compounds were evaluated for activity against 3D7 malaria parasites with methyl pheophorbide A () showing the strongest activity (IC 4.49 μM). Subsequent testing in a chemosuppression model showed that compound significantly attenuated peripheral blood parasitemia, leading to 79% and 87% chemosuppression following oral doses at 10 and 20 mg/kg, respectively.
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http://dx.doi.org/10.1021/acs.jnatprod.3c00743 | DOI Listing |
Nat Med
January 2025
Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
Malaria vaccines consisting of metabolically active Plasmodium falciparum (Pf) sporozoites can offer improved protection compared with currently deployed subunit vaccines. In a previous study, we demonstrated the superior protective efficacy of a three-dose regimen of late-arresting genetically attenuated parasites administered by mosquito bite (GA2-MB) compared with early-arresting counterparts (GA1-MB) against a homologous controlled human malaria infection. Encouraged by these results, we explored the potency of a single GA2-MB immunization in a placebo-controlled randomized trial.
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January 2025
Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou (IRR), Fundação Oswaldo Cruz (FIOCRUZ), Minas Gerais, Brazil.
Rapid Diagnostic Tests (RDTs) have been an important diagnostic tool for detecting P. falciparum malaria in resource-limited settings. Most tests are designed to detect the Histidine-rich Protein 2 (HRP2).
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January 2025
Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK.
The significance of multiplication rate variation in malaria parasites needs to be determined, particularly for Plasmodium falciparum, the species that causes most virulent infections. To investigate this, parasites from cases presenting to hospital in The Gambia and from local community infections were culture-established and then tested under exponential growth conditions in a standardised six-day multiplication rate assay. The multiplication rate distribution was lower than seen previously in clinical isolates from another area in West Africa where infection is more highly endemic.
View Article and Find Full Text PDFPLoS One
January 2025
School of Nursing and Public Health, College of Health Sciences, Howard College Campus, University of KwaZulu-Natal, Durban, South Africa.
Vector resistance, human population movement, and cross-border malaria continue to pose a threat to the attainment of malaria elimination goals. Border malaria is prominent in border regions characterised by poor access to health services, remoteness, and vector abundance. Human socio-economic behaviour, vectoral behaviour, access and use of protective methods, age, sex, and occupation have been identified in non-border regions as key predictors for malaria.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America.
Vector control is essential for eliminating malaria, a vector-borne parasitic disease responsible for over half a million deaths annually. Success of vector control programs hinges on community acceptance of products like long-lasting insecticide-treated nets (LLINs). Communities in malaria-endemic regions often link LLIN efficacy to their ability to control indoor pests such as bed bugs (Cimex lectularius L.
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