-
Nature Communications Jun 2024Transition metal-catalyzed asymmetric hydrogenation is one of the most efficient methods for the preparation of chiral α-substituted propionic acids. However, research...
Transition metal-catalyzed asymmetric hydrogenation is one of the most efficient methods for the preparation of chiral α-substituted propionic acids. However, research on this method, employing cleaner earth-abundant metal catalysts, is still insufficient in both academic and industrial contexts. Herein, we report an efficient nickel-catalyzed asymmetric hydrogenation of α-substituted acrylic acids affording the corresponding chiral α-substituted propionic acids with up to 99.4% ee (enantiomeric excess) and 10,000 S/C (substrate/catalyst). In particular, this method can be used to obtain (R)-dihydroartemisinic acid with 99.8:0.2 dr (diastereomeric ratio) and 5000 S/C, which is an essential intermediate for the preparation of the antimalarial drug Artemisinin. The reaction mechanism has been investigated via experiments and DFT (Density Functional Theory) calculations, which indicate that the protonolysis of the C-Ni bond of the key intermediate via an intramolecular proton transfer from the carboxylic acid group of the substrate, is the rate-determining step.
PubMed: 38942809
DOI: 10.1038/s41467-024-49801-0 -
Natural Product Research Jun 2024The study explored DC. for mosquito larvicidal potential by performing bioactivity-guided chemical investigation of its root extract resulting in isolation of the known...
The study explored DC. for mosquito larvicidal potential by performing bioactivity-guided chemical investigation of its root extract resulting in isolation of the known bioactive metabolite glaucarubinone (). Mosquito larvicidal activity of glaucarubinone () against the three vector species viz. and was determined using a modified WHO 2005 protocol. It was observed that larvae were the most susceptible species with LC 13.88 ppm and LC 70.01 ppm followed by and at 24 h of exposure. The mode of action as observed microscopically is the lysis of midgut and thorax cells of the third instar larvae. The crystal structure of the glaucarubinone () is reported for the first time using X-ray crystallography. This phytochemical product has the potential to act as a green alternative to existing chemical-based insecticides for integrated vector management.
PubMed: 38940013
DOI: 10.1080/14786419.2024.2371569 -
Journal of Global Health Jun 2024Malaria infection during pregnancy is associated with an increased risk of maternal death, as well as adverse birth outcomes. Intermittent preventive treatment in...
BACKGROUND
Malaria infection during pregnancy is associated with an increased risk of maternal death, as well as adverse birth outcomes. Intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) is known to improve pregnancy outcomes. However, the coverage of IPTp-SP in antenatal care (ANC) in sub-Saharan Africa remains well below the target. This study aims to estimate to what extent malaria service readiness affects the uptake of IPTp-SP during ANC visits in sub-Saharan African countries.
METHODS
This study included 3267 pregnant women attending ANC for the first time and 2797 pregnant women who had attended ANC more than a month ago in six sub-Saharan African countries. The readiness of malaria services at each institution includes four indicators: the presence of IPTp-SP guidelines, SP availability, integration of IPTp-SP service into ANC, and provider training on IPTp-SP. The outcome variable indicates whether a pregnant woman received IPTp-SP at her current ANC visit. A modified Poisson regression model estimated the associations between malaria service readiness and IPTp-SP uptake for women eligible for the first and subsequent doses.
RESULTS
For women eligible for their first dose, visiting an institution with available SP was associated with an increased probability of receiving IPTp-SP (risk ratio (RR) = 1.43; 95% confidence interval (CI) = 1.22 to 1.67, P < 0.001). For women who were eligible for their next dose, the availability of SP (RR = 1.17; 95% CI = 1.04 to 1.32, P = 0.008) and integration of IPTp-SP service into ANC (RR = 1.82; 95% CI = 1.21 to 2.74, P = 0.004) in the institution were associated with increased likelihood of IPTp-SP uptake. Counterfactual predictions indicated that enhanced provider training could boost IPTp-SP uptake in high-uptake countries, while better SP availability and IPTp-SP integration into ANC would significantly impact low-uptake countries.
CONCLUSIONS
For better IPTp-SP coverage, strategies should be customised. High uptake countries should focus on provider training, while low uptake ones should ensure IPTp-SP availability and service integration.
Topics: Humans; Female; Pregnancy; Antimalarials; Africa South of the Sahara; Pyrimethamine; Sulfadoxine; Malaria; Pregnancy Complications, Parasitic; Adult; Drug Combinations; Prenatal Care; Young Adult; Adolescent; Patient Acceptance of Health Care
PubMed: 38939971
DOI: 10.7189/jogh.14.04112 -
Case Reports in Ophthalmological... 2024To the best of our knowledge, we present the first case of type II acute macular neuroretinopathy (AMN) exhibiting in a patient suffering from malarial retinopathy...
To the best of our knowledge, we present the first case of type II acute macular neuroretinopathy (AMN) exhibiting in a patient suffering from malarial retinopathy concomitant with cerebral malaria acquired after travelling to West Africa without taking the necessary antimalarial prophylaxis. The patient complained of bilateral blurring of vision after being removed off sedation whilst at the intensive care unit. Subsequent examination revealed bilateral retinal haemorrhages, cotton-wool spots, and foveal pigmentary changes in keeping malarial retinopathy. Macular optical coherence tomography (OCT) revealed patchy hyperreflective changes at the level of the outer plexiform and outer nuclear layers (ONL) in keeping with the areas of deep capillary plexus flow void noted on OCT-angiography (OCT-A). This case report sheds more light on the extent of neurosensory retinal ischaemia in malarial retinopathy and showcases a new imaging biomarker which may be utilized in assessing and quantifying the functional deficit created by this disease.
PubMed: 38938742
DOI: 10.1155/2024/1577127 -
Current Molecular Pharmacology Jun 2024Artemisinin and its derivatives, the well-known anti-malarial drugs extracted from traditional Chinese medicine, have been implicated in treating fibrotic diseases....
BACKGROUND AND OBJECTIVES
Artemisinin and its derivatives, the well-known anti-malarial drugs extracted from traditional Chinese medicine, have been implicated in treating fibrotic diseases. However, whether artemisinin affects cardiac fibrosis in the pathogenesis of heart failure is still unknown. This study aimed to evaluate the possible effects of artemisinin on cardiac function and myocardial fibrosis in the heart failure model and to explore the underlying mechanisms.
METHODS
Isoproterenol was injected subcutaneously for induction of the cardiac fibrosis model. Proteomic analysis was performed after 4 four weeks of artemisinin treatment. Echocardiography was used to evaluate cardiac function and structure. Hematoxylin and eosin (H&E) staining, as well as Masson staining, were performed for histopathology. The α-SMA, collagen I, and III expression in the myocardium was detected by Immunohistochemical staining. The ratio of heart weight (HW) to body weight (HW/BW, mg/kg) and the ratio of heart weight to tibia length (HW/TL, mg/mm) were calculated as indicators for cardiac remodeling. Brain natriuretic peptide (BNP) levels were quantified in rat plasma using enzyme-linked immunosorbent assay (ELISA). In contrast, the protein levels of TGF-β1, p-Smad2/3, and Smad2/3 were assessed in myocardium and fibroblasts via western blot analysis. RT-qPCR analysis of Col-I, Col-III, α-SMA, NLRP3, Caspase-1, IL-1β, and IL-18 was performed in the heart.
RESULTS
Proteomic analysis identified 227 differentially expressed proteins (DEPs), including 119 upregulated and 108 downregulated proteins. These proteins were identified as the core proteins targeted by artemisinin for improving myocardial remodeling. GO annotation of the DEPs indicated that the DEPs were mainly associated with biological processes such as TGF-β and NLRP3 inflammasome regulation. In the in vivo study of an isoproterenol-induced SD rat cardiac remodeling model, we found that artemisinin administration significantly ameliorated cardiac dysfunction and reduced collagen production by suppressing TGFβ-1/Smads signaling and inhibiting NLRP3 inflammasome activation. As manifested by downregulating the expression of α-SMA, Col-I, and Col-III, NLRP3, IL-1β, IL-18, Caspase-1 mRNA, and TGF-β1, p-SMAD 2/3 protein in the myocardium. Similar beneficial effects of artemisinin were consistently observed in TGF-β1 treated primary cardiac fibroblasts.
CONCLUSIONS
Artemisinin relieves myocardial remodeling through TGF-β1/Smad2/3 pathway and NLRP3 inflammasome.
.PubMed: 38934281
DOI: 10.2174/0118761429304142240528093541 -
Pharmaceutics May 2024Malaria poses a global threat to human health, with millions of cases and thousands of deaths each year, mainly affecting developing countries in tropical and... (Review)
Review
Malaria poses a global threat to human health, with millions of cases and thousands of deaths each year, mainly affecting developing countries in tropical and subtropical regions. Malaria's causative agent is species, generally transmitted in the hematophagous act of female sp. mosquitoes. The main approaches to fighting malaria are eliminating the parasite through drug treatments and preventing transmission with vector control. However, vector and parasite resistance to current strategies set a challenge. In response to the loss of drug efficacy and the environmental impact of pesticides, the focus shifted to the search for biocompatible products that could be antimalarial. Plant derivatives have a millennial application in traditional medicine, including the treatment of malaria, and show toxic effects towards the parasite and the mosquito, aside from being accessible and affordable. Its disadvantage lies in the type of administration because green chemical compounds rapidly degrade. The nanoformulation of these compounds can improve bioavailability, solubility, and efficacy. Thus, the nanotechnology-based development of plant products represents a relevant tool in the fight against malaria. We aim to review the effects of nanoparticles synthesized with plant extracts on and while outlining the nanotechnology green synthesis and current malaria prevention strategies.
PubMed: 38931823
DOI: 10.3390/pharmaceutics16060699 -
Medicina (Kaunas, Lithuania) Jun 2024: Malaria continues to be a significant global health challenge. The efficacy of artemisinin-based combination therapies (ACTs) has declined in many parts of the Greater...
: Malaria continues to be a significant global health challenge. The efficacy of artemisinin-based combination therapies (ACTs) has declined in many parts of the Greater Mekong Subregion, including Vietnam, due to the spread of resistant malaria strains. This study was conducted to assess the efficacy of the Dihydroartemisinin (DHA)-Piperaquine (PPQ) regimen in treating uncomplicated malaria and to conduct molecular surveillance of antimalarial drug resistance in Binh Phuoc and Dak Nong provinces. : The study included 63 uncomplicated malaria falciparum patients from therapeutic efficacy studies (TES) treated following the WHO treatment guidelines (2009). Molecular marker analysis was performed on all 63 patients. Methods encompassed Sanger sequencing for mutations and quantitative real-time PCR for the gene. : This study found a marked decrease in the efficacy of the DHA-PPQ regimen, with an increased rate of treatment failures at two study sites. Genetic analysis revealed a significant presence of mutations and amplifications, indicating emerging resistance to artemisinin and its partner drug. : The effectiveness of the standard DHA-PPQ regimen has sharply declined, with rising treatment failure rates. This decline necessitates a review and possible revision of national malaria treatment guidelines. Importantly, molecular monitoring and clinical efficacy assessments together provide a robust framework for understanding and addressing detection drug resistance in malaria.
Topics: Humans; Artemisinins; Quinolines; Vietnam; Antimalarials; Malaria, Falciparum; Male; Female; Adult; Plasmodium falciparum; Drug Resistance; Adolescent; Middle Aged; Drug Therapy, Combination; Young Adult; Protozoan Proteins; Real-Time Polymerase Chain Reaction; Mutation; Piperazines
PubMed: 38929629
DOI: 10.3390/medicina60061013 -
Medicina (Kaunas, Lithuania) May 2024Hydroxychloroquine sulfate (HCQ) is a lysosomotropic agent administered in systemic lupus erythematosus and rheumatoid arthritis that has fewer toxic effects than...
Hydroxychloroquine sulfate (HCQ) is a lysosomotropic agent administered in systemic lupus erythematosus and rheumatoid arthritis that has fewer toxic effects than chloroquine. However, HCQ may still be responsible for retinal toxicity. In this study, we observed structural changes in the retinas of experimental rats after prolonged exposure to HCQ. We investigated several aspects regarding retinal changes, at both the histopathological and ultrastructural levels. We used 96 male albino Wistar rats distributed into four equal groups (n = 24 per group): the first three groups were treated with different doses of HCQ (50, 100, and 200 mg/kg HCQ, injected intraperitoneally in a single dose daily), and the last group (the control group, n = 24) was treated with saline solution administered in the same way (0.4 mL of saline solution). The treated groups received HCQ daily for 4 months, and every month, six animals from each group were sacrificed to assess retinal changes. The eyes were examined via optical (OM) and electronic microscopy (EM). Statistical analysis was deployed, and results regarding retinal morpho-photometry were acquired. We observed structural retinal changes in both high and low doses of HCQ; while high doses determined a significant thinning of the retina, lower doses caused retinal thickening. Morphological retinal changes upon exposure to HCQ are believed to be caused by accumulated HCQ in lysosomes found in retinal ganglion cells and in the inner nuclear and photoreceptor cell layers. Such changes were most evident in the group receiving HCQ intraperitoneally in doses of 100 mg/kg for a longer period (4 months). The present study highlights histopathological and ultrastructural retinal changes induced by chronic HCQ administration, which were strongly connected to the dosage and period of exposure.
Topics: Hydroxychloroquine; Animals; Rats, Wistar; Rats; Retina; Male; Antirheumatic Agents
PubMed: 38929463
DOI: 10.3390/medicina60060846 -
International Journal of Environmental... May 2024Multidrug- and artemisinin-resistant (ART-R) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region gene...
Multidrug- and artemisinin-resistant (ART-R) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region gene allows tracking mutations in parasite resistance to artemisinin. The increase in illegal miners in the Roraima Yanomami indigenous land (YIL) could favor ART-R parasites. Thus, this study aimed to investigate ART-R in patients from illegal gold mining areas in the YIL of Roraima, Brazil. A questionnaire was conducted, and blood was collected from 48 patients diagnosed with or mixed malaria (). The DNA was extracted and the gene was amplified by PCR. The amplicons were subjected to DNA-Sanger-sequencing and the entire amplified fragment was analyzed. Among the patients, 96% (46) were from illegal mining areas of the YIL. All parasite samples carried the wild-type genotypes/ART-sensitive phenotypes. These data reinforce the continued use of artemisinin-based combination therapies (ACTs) in Roraima, as well as the maintenance of systematic monitoring for early detection of parasite populations resistant to ART, mainly in regions with an intense flow of individuals from mining areas, such as the YIL. This is especially true when the achievement of falciparum malaria elimination in Brazil is planned and expected by 2030.
Topics: Artemisinins; Brazil; Plasmodium falciparum; Humans; Antimalarials; Drug Resistance; Malaria, Falciparum; Male; Mining; Adult; Female; Middle Aged; Young Adult; Adolescent; Genotype
PubMed: 38928926
DOI: 10.3390/ijerph21060679 -
International Journal of Molecular... Jun 2024It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid...
It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid arthritis. The molecular chaperone HSP60 alone induces inflammatory cytokine IL-6 and the co-chaperone HSP10 alone inhibits IL-6 induction. HSP60 and HSP10 form a complex in the presence of ATP. We analyzed the effects of Mizoribine, which is structurally similar to ATP, on the structure and physiological functions of HSP60-HSP10 using Native/PAGE and transmission electron microscopy. At low concentrations of Mizoribine, no complex formation of HSP60-HSP10 was observed, nor was the expression of IL-6 affected. On the other hand, high concentrations of Mizoribine promoted HSP60-HSP10 complex formation and consequently suppressed IL-6 expression. Here, we propose a novel mechanism of immunosuppressive action of Mizoribine.
Topics: Ribonucleosides; Interleukin-6; Chaperonin 60; Humans; Immunosuppressive Agents; Animals; Mice
PubMed: 38928158
DOI: 10.3390/ijms25126452