ANTIMICROBIAL

The growing global concern of antimicrobial resistance has fueled the hunt for alternative nanomaterials with therapeutic promise. This work used a green approach to create manganese– magnesium binary oxide (Mn–MgO) nanoparticles. Ficus exasperata leaf extract in alkaline environments (pH 9–10) act as a stabilizing and reducing agent. The nanoparticles' crystalline structure was validated by X-ray diffraction (XRD) examination, with distinctive peaks at 2θ values of 29.4°, 42.9°, and 62.0°, with an average crystallite size of 18 nm determined by the Debye–Scherrer equation. FTIR (Fourier Transform Infrared) spectrum showed notable peaks at 3339.69 cm⁻¹ (O–H stretching), 1543.11 cm⁻¹ (amide/aromatic C=C), and 1017.50 cm⁻¹ (C–O stretching), suggesting the existence of capping agents made of phytochemicals. Highly aggregated, irregular particles were found using scanning electron microscopy (SEM) that created a porous cluster structure. Energy Dispersive X-ray Spectroscopy (EDS) was used to verify the elemental composition; manganese (51.40 wt%), magnesium (35.00 wt%), and oxygen (5.20 wt%) were the primary elements. A primarily mesoporous structure was indicated by Brunauer–Emmett–Teller (BET) analysis, which showed a high specific surface area of 212.13 m²/g, a total pore volume of 0.106 cm³/g, and average pore diameters of 2.11 nm (BJH), 2.65 nm (DFT), and 3.04 nm (DA). A hybrid micro–mesoporous architecture was confirmed by the classification of the nitrogen adsorption–desorption isotherm as Type IV with an H3 hysteresis loop. There were no zones of inhibition (0 mm) against Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida albicans when antimicrobial activity was assessed using the agar well diffusion method at doses ranging from 7.813 to 62.5 mg/mL. As a result, values for minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) were not determined. The Mn–MgO nanoparticles showed no discernible antibacterial activity despite having a large surface area and nanoscale crystallinity. This was probably caused by particle aggregation and surface passivation by phytochemical residues. These results demonstrate how important surface shape and accessibility are in influencing the bioactivity of green-synthesised nanoparticles.

The emergence of multi-drug resistant microbes has rekindled the interest on plant derived compounds as alternatives to existing antimicrobial agents.This study d et e rmi n e d the antimicrobial property of ethyl acetate extract of the fibrous stem of Bryophyllum pinnatum and phytochemical constituents of the fibrous stem. The ethyl acetate extract of the fibrous stem did not show any antimicrobial activity against the clinical fungal and bacterial isolates at 0.3g/mL concentration of the extract. Phytochemical analysis showed that alkaloids, flavonoids, terpenoids, tannins,saponins and glycoside which are responsible for antimicrobial activity were not detected. Gas Chromatography -Mass Spectroscopy also identified various phytocomponents. The ethyl acetate extract did not show anti-microbial activity.

Background: Oral hygiene is an important part of the body overall well-being, and should be treated with the utmost care to prevent dental problems. Acalypha wilkesiana Muell. Arg. Euphorbiaceae), commonly known as copper leaf, is a tropical lant native to West Africa, with notable antimicrobial activities. This study was carried out to investigate the antimicrobial properties of the methanol leaf extract of Acalypha wilkesiana formulated as herbal toothpaste. Method: Toothpaste was formulated using the leaf extract of A. wilkesiana. The extract was incorporated into a toothpaste base prepared using calcium carbonate, starch, glycerin, sodium lauryl sulfate, saccharine and peppermint oil. Sensory and physicochemical properties of the toothpaste were evaluated. Antimicrobial evaluation was by the Agar well diffusion method against Staphylococcus aureus, Escherichia coli, acillus subtilis, Pseudomonas aeruginosa, Klebsiella aerogenes, Candida albicans and Aspergillus niger at concentrations of 100-500
mg/ml. Results: The A. wilkesiana formulated toothpaste had a pleasant smell and was sweet to taste. It had good foaming abilities with a pH range of 7.4-7.8. The formulated herbal toothpaste had poor antibacterial activity but no antifungal activity against the clinical isolates at low concentrations. Significant activities were recorded at 500 mg/ml against all five (5) bacteria isolates, with Bacillus subtilis recording the highest zone of inhibition. Conclusion: The formulated A. wilkesiana toothpaste showed significant antibacterial effects against microbes implicated in periodontal diseases and dental caries, hence serving as a potential alternative to orthodox toothpastes for maintaining oral hygiene. Keywords: Acalypha wilkesiana, Euphorbiaceae, Antimicrobial, Toothpaste

The rising prevalence of multidrug-resistant uropathogenic Escherichia coli (UPEC) highlights the urgent need for alternative antimicrobial agents. This study aimed to evaluate the antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill kinetics of ethanol and aqueous extracts of Hibiscus sabdariffa calyces against multidrug resistant UPEC isolates before and after plasmid curing. Antibacterial activity was determined using agar well diffusion, MIC and MBC by broth dilution, and time-kill assays by plate count method. The ethanol extract consistently showed stronger antibacterial activity than the aqueous extract, with lower MIC and MBC values and faster bacterial elimination in time-kill assays. Plasmid curing enhanced the susceptibility of UPEC to both extracts. Conclusively, Hibiscus sabdariffa, particularly the ethanol extract, demonstrated promising antibacterial potential against MDR UPEC, warranting further studies on dosage, and safety.

This study investigates the antimicrobial and antioxidant properties of ethanol and aqueous extracts of Curcuma longa (turmeric) rhizomes against clinical nasal isolates. The research aims to evaluate the efficacy of these extracts in combating microbial infections and their potential as natural antioxidants. The chemical composition of the extracts was characterized using Gas Chromatography-Mass Spectrometry (GC-MS), revealing a diverse array of bioactive compounds, including terpenes, fatty acids, phenolic compounds, and sterols. Antimicrobial activity was assessed using the broth dilution method, while antioxidant potential was determined through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The results indicate that the ethanolic extract exhibited significant antimicrobial activity against nasal isolates, including Micrococcus species, Moraxella catarrhalis, and Streptococci species. Additionally, the aqueous extract demonstrated strong antioxidant properties, with a linear increase in activity correlating with concentration. The findings suggest that Curcuma longa extracts, particularly the ethanolic extract, hold promise as natural antimicrobial agents, while the aqueous extract shows potential as a potent antioxidant. This study underscores the therapeutic potential of Curcuma longa in addressing antibiotic resistance and oxidative stress-related conditions, providing a scientific basis for its traditional use in medicine and its application in modern healthcare

Antimicrobial resistance is a major global health problem that requires exploration for new natural drug alternatives. This study examines the extraction process, chemical analysis, and assessment of the antimicrobial properties of the volatile oils from Cymbopogon citratus and Ageratum conyzoides. Whole volatile oils were extracted from the two plants by hydrodistillation. The chemical constituents of both are compared by gas chromatography-mass spectrometry (GC-MS). Five bacterial and two fungal strains were chosen for the antimicrobial studies. The cup-plate agar diffusion method was used to test microbial susceptibility to the volatile oils. The oil yield of the two plants was 1.4% for C. citratus and 0.0079% for A. conyzoides. GC-MS analysis indicated that citral is the main ingredient of C. citratus, while A. conyzoides was high in precocene. C. citratus oil exhibited potent broad-spectrum antibacterial activity against in vitro-tested pathogenic bacteria and fungi in a dose-dependent concentration. With a potent antifungal activity. On the other hand, the essential oil of A. conyzoides showed weak performance and hence inhibited only P. aeruginosa and C. albicans at the highest concentration tested (25% w/v) and exhibited a weak effect against the other clinical isolates used in the study. C. citratus volatile oil demonstrated a very good antimicrobial activity and could serve as a good antimicrobial agent against bacterial and fungal infection

This research explored the chemical composition and antimicrobial activity of the essential oil derived from Ocimum basilicum Linn. (Sweet Basil). The oil was obtained through
hydrodistillation using a Clevenger-type apparatus, producing a 0.71% (v/w) average yield of a light-yellow, aromatic extract. Chemical profiling carried out with Gas Chromatography– Mass Spectrometry (GC–MS) revealed nine major constituents, with estragole (46.12%), eucalyptol (16.87%), and linalool (10.45%) as the predominant compounds, supported by smaller amounts of eugenol, thymol, β-caryophyllene, bisabolene, and τ-cadinol. The antimicrobial properties of the oil were assessed using agar well diffusion and minimum inhibitory concentration (MIC) assays against selected bacterial and fungal strains. Results indicated that the oil displayed dose-dependent inhibitory activity, showing marked effects against Staphylococcus aureus (19 mm), Bacillus subtilis (18 mm), Candida albicans (17 mm), and Aspergillus niger (21 mm), while Escherichia coli and Pseudomonas aeruginosa exhibited resistance. The observed antimicrobial efficacy was linked to the synergistic actions of oxygenated monoterpenes and phenylpropanoids in the oil. These findings demonstrate that O. basilicum essential oil exhibits strong antimicrobial potential, especially toward Gram-positive bacterial and fungal organisms, thereby validating its traditional medicinal applications. The dominance of estragole and eucalyptol suggests the Nigerian-grown species belongs to the estragole–eucalyptol chemotype. In summary, the study establishes O. basilicum oil as a viable natural antimicrobial candidate with promising applications in pharmaceutical, nutraceutical, and cosmetic industries, contributing to sustainable strategies against antimicrobial resistance.