Biology subjects

Belle Ebanda Kedi, P.

Publications and source records attributed to Belle Ebanda Kedi, P..

6 recordsLinked to original sources

bioRxiv2026

Ocimum gratissimum essential oil nanoemulsions as a safe topical nanoplatform for antibacterial and wound-healing activities

BackgroundNatural essential oils exhibit antimicrobial and wound-healing properties, but their therapeutic application is limited by poor water solubility, volatility, and instability. This study developed and characterized a nanoemulsion of Ocimum gratissimum essential oil (OGNe) and evaluated its physicochemical properties, dermal safety, antibacterial activity, and wound-healing potential. MethodsEssential oil was obtained by hydrodistillation and formulated into nanoemulsions by high-speed stirring emulsification. Physicochemical properties, including pH, droplet size, polydispersity index, and storage stability, were determined. Acute dermal toxicity was assessed in Wistar rats following OECD Test Guideline 402. Antibacterial activity was evaluated using broth microdilution, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assays. Wound-healing efficacy was investigated using an excision wound model over 21 days using distilled water and trolamine serving as controls. ResultsOGNe exhibited a stable milky appearance, near-neutral pH, and droplet sizes ranging from 26 to 224 nm. No signs of dermal toxicity or behavioral abnormalities were observed after topical administration. The nanoemulsion showed selective antibacterial activity, with the highest susceptibility against Acinetobacter baumannii (MIC = 1.125 L/mL), whereas Escherichia coli remained resistant. Time-kill assays demonstrated concentration-dependent bacteriostatic activity. In vivo, OGNe significantly accelerated wound contraction from day 3 onward (p < 0.0001), achieving healing rates comparable to or exceeding those of trolamine during the inflammatory and proliferative phases. ConclusionOcimum gratissimum nanoemulsions represent stable, biocompatible topical formulations that combine selective antibacterial activity with enhanced wound healing, supporting their potential as phytopharmaceutical nanoformulations for the management of acute skin wounds.

pharmacology and toxicology↗

bioRxiv2026

Mimosa pudica-derived zinc oxide nanoparticles preserve mesenchymal stromal cell viability, morphology, and osteogenic competence

IntroductionMusculoskeletal disorders remain a major cause of disability worldwide and require non invasive regenerative strategies that support tissue repair. Green-synthesized zinc oxide nanoparticles (ZnONPs) have attracted interest because of their biocompatibility and biological activity. This study investigated the synthesis of Mimosa pudica-derived ZnONPs (ZnOMP) and evaluated their effects on human bone marrow mesenchymal stromal cells (BM-MSCs). MethodologyZnOMP were synthesized using an aqueous extract of Mimosa pudica leaves and characterized by UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction, SEM, EDS, and TEM. BM-MSCs isolated from human bone marrow were exposed to ZnOMP, plant extract, and synthesized ZnO nanoparticles. Cell metabolic activity was assessed by MTT assay after 1, 3, and 5 days. Cytoskeletal and nuclear morphology were analyzed by fluorescence microscopy and CellProfiler-based morphometry. Osteogenic differentiation was evaluated after 21 days using Alizarin Red S staining and quantification. ResultsSpectroscopic and microscopic analyses confirmed the successful formation of phytochemical-capped ZnOMP nanoparticles with nanoscale dimensions and specific elemental composition. ZnOMP maintained significantly higher metabolic activity than Mimosa pudica extract or ZnO at both 150 and 300 g/mL. Morphometric profiling revealed that Mimosa pudica extract induced the most pronounced changes in nuclear morphology, reflecting enhanced nuclear plasticity and substantial remodeling of nuclear architecture, whereas ZnOMP preserved cellular and nuclear features closer to untreated controls. During osteogenic induction, ZnOMP did not impair matrix mineralization and preserved the ability of BM-MSCs to form a mineralized extracellular matrix. ConclusionMimosa pudica-mediated ZnO nanoparticles combine favorable biocompatibility with preservation of mesenchymal stem cell morphology and osteogenic competence. These findings support their potential use as bioactive nanomaterials for musculoskeletal tissue engineering and regenerative medicine.

pharmacology and toxicology↗

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

Magnesium hydroxide nanoneedles derived from Anthocleista schweinfurthii Gilg (Loganiaceae) support mesenchymal stromal cell proliferation and wound healing

Multiple metallic nanoparticles are able to promote cellular and tissue health, but these nanoparticles can be difficult to synthesize and can also cause unintended side-effects. Here, we study the effects on wounds healing and bone reparation of Mg(OH)2 from Anthocleista schweinfurthii Gilg (Loganiaceae) leaves (AS), which are local to the Africa region and have been used in traditional medicine to treat injuries. Mg(OH)2 nanoneedles were synthesized from aqueous extracts of Anthocleista schweinfurthii Gilg (Loganiaceae) leaves (AS) and magnesium nitrate. The quick polydispersing and crystallized Mg(OH)2-metal interface was found to be covered in plant secondary metabolites. We call this compound Mg(OH)2-AS. Using an acute dermal toxicity experiment on animal model, we determined that Mg(OH)2-AS is safe for topical application. In vitro experiments suggest that Mg(OH)2-AS has anti-inflammatory potential, and in vivo wound healing assays in Wistar rats indicate that Mg(OH)2-AS can enhance wound healing. To investigate Mg(OH)2-AS effects on the cellular level, we used bone marrow mesenchymal stromal cells (BM-MSCs). In contrast to pure Mg(OH)2 or AS, cell viability and proliferation were not impaired by Mg(OH)2-AS. Cell morphology remained unchanged upon media supplementation with Mg(OH)2-AS. Preliminary results further indicate enhanced osteogenic differentiation of BM-MSCs in media supplied with ascorbic acid, {beta}-glycerophosphate and dexamethasone and addition of Mg(OH)2-AS. These findings motivate further research towards the inclusion of the material in implants for bone fracture healing.

pharmacology and toxicology↗