Biology subjects

Eya'ane Meva, F.

Publications and source records attributed to Eya'ane Meva, F..

5 recordsLinked to original sources

bioRxiv2025

Metabolomics reveals synergistic antimalarial drug pairing effects against Plasmodium falciparum in vitro

BackgroundThe development of new drugs against afflictions that disproportionately impact poorly resourced areas around the globe is an expensive endeavor. As cost-effective alternatives, strategic combinations of approved drugs can be used to enhance the efficacy against Plasmodium falciparum. Understanding the metabolic consequences of such combinations is essential for optimizing treatment strategies and delaying drug resistance. MethodsAn integrated metabolomic and pharmacological analysis was performed on P. falciparum exposed to chloroquine (CQ), pyrimethamine (PY), sulfadoxine (SD), and their combinations (SDPY and SDCQ). Dose{square}response assays were used to quantify drug potency, whereas untargeted metabolomic profiling was used to assess pathway-level perturbations associated with individual and combined treatments. ResultsDose{square}response assays confirmed the nanomolar potency of PY (IC = 12.5 nM) and CQ (IC = 11 nM) compared with the micromolar efficacy of SD (IC = 9.1 {micro}M), which is consistent with its role as a synergistic antifolate partner. Metabolomic profiling revealed that PY strongly disrupted folate-dependent pyrimidine biosynthesis, leading to deoxyuridine and dUMP accumulation, whereas SD caused milder perturbations, which was consistent with DHPS inhibition. CQ produced modest metabolic effects alone but markedly amplified antifolate-induced stress when combined with PY. Drug combinations generated metabolic responses that are distinct from those resulting from individual treatments. Across antifolate combinations, consistent trends included reduced amino acid pools, suppression of thiamine and glutathione metabolism, and enhanced PPP inhibition, leading to broad disruption of nucleotide, redox, and carbon metabolism. ConclusionsPyrimidine suppression has emerged as the central hallmark of antifolate-based therapy in P. falciparum. The distinct synergistic signatures observed with drug combinations support their potential to enhance efficacy and delay resistance. These findings provide a mechanistic foundation for guiding antimalarial combination policies, optimizing therapeutic regimens, and strengthening rational drug-design strategies.

systems biology↗

bioRxiv2025

Antibacterial potential of selected extracts and silver nanoparticles from bacterial endophyte harboured by Cola acuminata and Cola nitida (Sterculiaceae) roots

IntroductionAntimicrobial resistance (AMR) is currently a global health issue in most countries. Harnessing endophytic at present. Antibiotic resistance occurs when bacteria can adapt and grow in the presence of antibiotics. Endophytic microorganisms as bio-factory of natural bioactive compounds, and their potential in nanotechnology remains largely under explored. The aim of this study was to evaluate the antibacterial activity of extracts and silver nanoparticles synthesised using bacterial endophytes isolated from Cola acuminata and Cola nitida roots. MethodologyThe roots of each plant were harvested, washed, cut and surface sterilised. The sterile pieces were placed on the surface of nutrient agar and incubated, after which the microorganisms were sub-cultured until pure colonies were obtained. Secondary metabolite production was then undertaken over a 12-day fermentation period in Mueller Hinton Broth, conducted under stringent aseptic conditions. Each microorganism was fermented in two different tanks. The first was used for the preparation of crude extracts, and the second for the synthesis of nanoparticles. The in vitro antibacterial activity was determined using the broth microdilution method against Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter sp. and Escherichia coli. The MIC and the time-kill kinetic were used to determine the inhibiting parameters. The endophytes that produced the most promising effects were identified using microscopy and MALDI-TOF techniques. Results22 extracts were obtained from Cola nitida and Cola acuminata endophytes extracts (16 and 6 respectively. Crude extracts and silver nanoparticle). The most active material were the crude extracts from Cola acuminata endophytes were found to be the most active preparations. The MALDI-TOF identification method yielded the designation of NPMRU 6508, NPMRU 6511, NPMRU 7045 and NPMRU 7063 as Bacillus cereus. Furthermore, NPMRU6113 and NPMRU7047 were identified as Brevibacterium sp. ConclusionThis study supports the use of endophytes derived from Cola acuminata and Cola nitida roots to combat four bacterial strains involved in the development of antibiotic resistance.

microbiology↗

bioRxiv2024

Cylicodiscus gabunensis (FABACEAE) aqueous stem bark extract mediated silver nanoparticle enhance anti-inflammation on Wistar rats

IntroductionPlants are a source of bioactive ingredient that can play a key role in development of new drugs. In recent years, plant mediated-biological synthesis of nanoparticles has gained importance due to its simplicity, cost effectiveness and eco-friendly nature. To the best of our readings, nanoparticule from Cylicodiscus gabunensis stem bark is still untaped. This work therefore aimed at assessing the anti-inflammatory properties of the silver nanoparticles obtained from the aqueous extract of the stem bark of Cylicodiscus gabunensis(Cg). MethodologyCylicodiscus gabunensis extract was prepared by infusion-followed by the biosynthesis of silver nanoparticles. The synthesis was monitored by color and UV-Vis spectrophotometry. Infrared spectroscopy aimed at revealing the functional groups present at the surface of the nanoparticles. Structural elucidation was done by powder X-ray crystallography, while microstructure and elemental mapping was performed with scanning electron microscopy and energy dispersive X-ray spectroscopy. In vitro anti-inflammatory test was done using the BSA denaturation based test. The acute toxicity was done using the OEDC 425 guideline. carrageenan-induced rat paw oedema model was used to ascertain the in vivo anti-inflammatory effects. ResultsPhytochemical screening of the aqueous extract of Cylicodiscus gabunensis revealed the presence of polyphenols, flavonoids, alkaloids, coumarins, saponins, triterpenes, steroids, reducing sugar, tannins, and the absence of anthraquinone. The surface Plasmon resonance peak in the UV-Vis spectrum shows absorption spectra between 380 and 550 nm. Stability studies done over time showed that the nanoparticles were stable even after two months of synthesis. IR spectroscopy revealed the presence of O-H, N-H, C{equiv}C, C=C, C-O, and C=O groups. PXRD confirms the formation of silvernanoparticles (AgNPs) while nanograins of various forms were visualized by SEM and EDX. No toxic sign was observed. The maximum inhibitory percentages were 95% at 200 {micro}g/mL and 91% at 400 g/Kg for in vitro and in vivo anti-inflammatory effects, respectively. ConclusionThis paper spot the light on silver nanoparticle from Cylicodiscus gabunensis aqueous stem bark for their anti-inflammatory effect on paw oedema model.

pharmacology and toxicology↗

bioRxiv2024

Anti-inflammatory assessment of zinc oxide nanoparticles mediated Aframomum citratum (C. Pereira) K. Schum (Zingiberaceae) in Wistar rats

IntroductionZinc oxide nanoparticles (ZnONPs) have been synthesized using a wide range of techniques, including green chemistry, because of their versatility, cost effectiveness, and environmentally friendly nature, offering thereby interesting and inexpensive therapeutic options. This study aimed to develop zinc oxide nanoparticles as an anti-inflammatory agent using Aframomum citratum seed extract. MethodologyZnONPs were prepared by the reaction between zinc nitrate and an alkalineaqueous extract of A. citratum seeds. The isolated nanoparticles were then characterized using UV-Vis, FTIR, SEM/EDX, PXRD and TEM techniques. The toxicological profile was assessed at a limited dose of 2000 mg/kg in rats, and methods for heat denaturation of egg albumin, stabilization of red blood cell membranes and inhibition of carrageenan-induced plantar oedema were studied to assess anti-inflammatory properties. ResultsThe formation of ZnONPs was observed by a color change and the appearance of the plasmon resonance peak at 360 nm in the UV-Vis spectrum while FTIR confirmed the presence of secondary metabolites; SEM confirmed the presence of multiform aggregates, and TEM visualize point like particles. EDS confirmed the presence of Zn atoms within the synthetized material. The toxicological profile studied showed no harmful signs; zinc oxide nanoparticles synthesized from A. citratum seed extract showed high inhibition percentages of 86 (1mg/mL); 77 (0.6mg/mL) and 79(1mg/mL) when subjected to inhibition of heat-induced egg albumin denaturation, red cell membrane stabilization and oedema induction by carrageenan respectively, not significatively different compared with diclofenac sodium as positive controls. ConclusionZinc oxide nanoparticles synthesized and characterized from A. citratum seed extract act as a potent anti-inflammatory agent and are devoid of acute oral toxicity.

pharmacology and toxicology↗

bioRxiv2024

Green synthesis, characterization, and potential antimicrobial studies of Ag-MgO nanocomposites mediated from Talinum triangulare leaf extract

In this study, Ag-MgONCs (silver-magnesium oxide nanocomposites) were fabricated using Talinum triangulare leaf extract as a renewable, mild reducing, and stabilizing agent. The synthesis process involved molecular interactions between pre-prepared AgNPs (silver nanoparticles) and in situ-prepared MgO. Confirmation of the nanocomposites came from micrographic images obtained through SEM-EDX analysis. Dynamic light scattering (DLS) revealed a characteristic nanocomposite size of 295 nm. The infrared spectrum (FTIR) proved interactions between T. triangulare and Ag. Additionally, X-ray patterns of AgNPs and Ag-MgONCs confirmed hexagonal and cubic crystalline states, respectively, with average particle sizes of 17 nm. Furthermore, an in vitro analysis against five bacterial strains (Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus mirabilis) revealed pronounced activity of the nanocomposites, particularly against Proteus mirabilis, indicating bactericidal potential.

pharmacology and toxicology↗