A5040670576- Malaria Research and Control
- Computational Drug Discovery Methods
- Mosquito-borne diseases and control
- Bioactive natural compounds
- Traditional and Medicinal Uses of Annonaceae
- vaccines and immunoinformatics approaches
- Drug-Induced Hepatotoxicity and Protection
- Parasites and Host Interactions
- HIV/AIDS drug development and treatment
- Bioactive Compounds and Antitumor Agents
- Biological and pharmacological studies of plants
- Natural product bioactivities and synthesis
- Ethnobotanical and Medicinal Plants Studies
- Trypanosoma species research and implications
- Morinda citrifolia extract uses
- Biological Stains and Phytochemicals
- Hemoglobinopathies and Related Disorders
- Phytochemistry and Biological Activities
- Hepatitis C virus research
- Research on Leishmaniasis Studies
- Phytochemistry and biological activity of medicinal plants
- Diverse Scientific Research Studies
- Synthesis and Biological Activity
- Synthesis and biological activity
- HIV Research and Treatment
United States Army Medical Research Directorate - Africa
2015-2025
Kenya Medical Research Institute
2016-2025
Strathmore University
2024
Maseno University
2013-2021
Makerere University
2012
Single Nucleotide Polymorphisms (SNPs) in the Pfmdr1, and Pfcrt, genes of Plasmodium falciparum may confer resistance to a number anti-malaria drugs. Pfmdr1 86Y haplotypes at Pfcrt 72-76 have been linked chloroquine (CQ) as well amodiaquine (AQ) resistance. mefloquine (MQ) lumefantrine (LU) sensitivities are 86Y. Additionally, K76 allele carrying parasites shown tolerance LU. We investigated association between 86/Pfcrt P. CQ, AQ, MQ LU using field samples collected during 2008–2011 from...
The epidemiology and severity of non-falciparum malaria in endemic settings has garnered little attention. We aimed to characterise the prevalence, interaction, clinical risk factors, temporal trends Plasmodium species among symptomatic individuals presenting at health-care facilities Kenya.We diagnosed analysed infecting (Plasmodium falciparum, ovale curtisi, wallikeri, malariae) via PCR samples collected between March 1, 2008, Dec 31, 2016, from six hospitals located different regions...
Background. RTS,S/AS01 vaccine efficacy (VE) was previously shown to be lower in African adults than malaria-naive US adults, potentially due concurrent Plasmodium falciparum (Pf) infections. We investigated whether treatment of infection prior vaccination would lead improved VE and immunogenicity. Methods. A Phase 2b study Kenyan evaluated the RTS,S/AS01E conjunction with antimalarial chemopreventive drugs. Participants, grouped by baseline presence or absence Pf infections, were randomized...
Abstract Malaria remains a significant health challenge in sub‐Saharan Africa, accounting for 90% of the global burden disease. Recent studies have reported an increase number malaria cases and decrease deaths. However, these gains can be reversed by emerging resistance to artemisinin changing climatic conditions. Over past 30 years, Africa has adopted combination therapy (ACT) treat uncomplicated malaria. Increasingly, reports parasitic mutations conferring tolerance emerged several...
<title>Abstract</title> <bold>Background</bold> This study evaluated the polymorphisms of <italic>Pfk13</italic>gene alongside other malaria drug resistance markers in clinical samples from eight geographically distinct locations Kenya to determine prevalence mutations associated with partial artemisinin resistance. <bold>Methods</bold> Between 2018 and 2024, blood individuals symptoms uncomplicated at hospitals four five transmission zones were sequenced for single nucleotide (SNPs)...
In vitro drug sensitivity and molecular analyses of Plasmodium falciparum track resistance. DNA-binding fluorescent dyes like SYBR Green I may allow field laboratories, proximal to P. collection sites, conduct assays. 2007–2008, we assayed 121 isolates from western Kenya for 50% inhibitory concentrations (IC 50 ) against 6 antimalarial drugs using a in assay: 91 immediate ex vivo (IEV) 30 culture-adapted, along with reference clones D6 (chloroquine [CQ] sensitive) W2 (CQ resistant). We also...
Artemether-lumefantrine (AL) became the first-line treatment for uncomplicated malaria in Kenya 2006. Studies have shown AL selects SNPs pfcrt and pfmdr1 genes recurring parasites compared to baseline infections. The genotypes associated with selection are K76 N86, 184F D1246 pfmdr1. To assess temporal change of these western Kenya, 47 parasite isolates collected before (pre-ACT; 1995-2003) 745 after (post-ACT; 2008-2014) introduction were analyzed. In addition, associations haplotype...
The development of artemisinin (ART)-resistant parasites in Southeast Asia (SEA) threatens malaria control globally. Mutations the Kelch 13 (K13)-propeller domain have been useful identifying ART resistance SEA. combination therapy (ACT) remains highly efficacious treatment uncomplicated Sub-Saharan Africa (SSA). However, it is crucial that efficacy ACT closely monitored. Toward this effort, study profiled prevalence K13 nonsynonymous mutations different ecological zones Kenya and time...
Abstract Background Anti-malarial drug resistance in Kenya prompted two policy changes within a decade: sulphadoxine-pyrimethamine (SP) replaced chloroquine (CQ) as the first-line anti-malarial 1998 and artemether-lumefantrine (AL) SP 2004. Two cross-sectional studies were conducted to monitor prevalence of molecular markers over period which was used anti-malarial. The baseline study carried out from 1999-2000, shortly after implementation SP, follow-up occurred 2003-2005, during transition...
Abstract Drug discovery is an intricate and costly process. Repurposing existing drugs active compounds offers a viable pathway to develop new therapies for various diseases. By leveraging publicly available biomedical information, it possible predict compounds’ activity identify their potential targets across diverse organisms. In this study, we aimed assess the antiplasmodial of from Repurposing, Focused Rescue, Accelerated Medchem (ReFRAME) library using in vitro bioinformatics...
From the root bark of Erythrina abyssinica a new pterocarpene [3-hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene] and isoflav-3-ene [7,4′-dihydroxy-2′,5′-dimethoxyisoflav-3-ene] were isolated. In addition, known compounds erycristagallin, licoagrochalcone A, octacosyl ferulate triacontyl 4-hydroxycinnamate identified. The structures determined on basis spectroscopic evidence. crude extract flavonoids isoflavonoids obtained from roots this plant showed antiplasmodial activities.
The acetone extracts of the root bark and stem Erythrina sacleuxii showed antiplasmodial activities against chloroquine-sensitive (D6) chloroquine-resistant (W2) strains Plasmodium falciparum. Chromatographic separation extract afforded a new isoflavone, 7-hydroxy-4′-methoxy-3′-prenylisoflavone (trivial name 5-deoxy-3′-prenylbiochanin A) along with known isoflavonoids as principles. Flavonoids isolated from E. were also tested activities. structures determined on basis spectroscopic evidence.
Abstract Genetic analysis of molecular markers is critical in tracking the emergence and/or spread artemisinin resistant parasites. Clinical isolates collected western Kenya pre- and post- introduction combination therapies (ACTs) were genotyped at SNP positions regions strong selection signatures on chromosome 13 14, as described Southeast Asia (SEA). Twenty five SNPs using Sequenom MassArray pfmdr 1 gene copy number by real-time PCR. Parasite clearance half-life vitro drug sensitivity...
The malaria SYBR green assay, which is used to profilein vitrodrug susceptibility ofPlasmodium falciparum, a reliable drug screening and surveillance tool. Malaria field efforts provide isolates with various low levels of parasitemia. To be advantageous, sensitivity assays should perform reproducibly among starting parasitemia rather than at one fixed initial value. We examined the assay standardized procedure developed by Worldwide Antimalarial Resistance Network (WWARN) for its ability...
ABSTRACT In combination with antibiotics, quinine is recommended as the second-line treatment for uncomplicated malaria, an alternative first-line severe and of malaria in first trimester pregnancy. Quinine has been shown to have frequent clinical failures, yet mechanisms action resistance not fully elucidated. However, linked polymorphisms multiple genes, including multidrug 1 (Pf mdr1 ), chloroquine transporter crt sodium/hydrogen exchanger gene nhe1 ). Here, we investigated association...
Sulphadoxine-pyrimethamine (SP), an antifolate, was replaced by artemether-lumefantrine as the first-line malaria drug treatment in Kenya 2004 due to wide spread of resistance. However, SP still remains recommended for intermittent preventive pregnant women and infants (IPTP/I) owing its safety profile. This study assessed prevalence mutations dihydrofolate reductase (Pfdhfr) dihydropteroate synthase (Pfdhps) genes associated with resistance samples collected between 2008 2012. Field...
Three new (1–3) and six known rotenoids (5–10), along with three isoflavones (11–13), were isolated from the leaves of Millettia oblata ssp. teitensis. A glycosylated isoflavone (4), four (14–18), one chalcone (19) root wood extract same plant. The structures elucidated by NMR mass spectrometric analyses. absolute configuration chiral compounds was established a comparison experimental ECD VCD data those calculated for possible stereoisomers. This is first report on use to assign rotenoids....