Significant Antimicrobial Activity Research Articles

Progress in the Identification and Design of Novel Antimicrobial Peptides Against Pathogenic Microorganisms

Abstract The occurrence and spread of antimicrobial resistance (AMR) pose a looming threat to human health around the world. Novel antibiotics are urgently needed to address the AMR crisis. In recent years, antimicrobial peptides (AMPs) have gained increasing attention as potential alternatives to conventional antibiotics due to their abundant sources, structural diversity, broad-spectrum antimicrobial activity, and ease of production. Given its significance, there has been a tremendous advancement in the research and development of AMPs. Numerous AMPs have been identified from various natural sources (e.g., plant, animal, human, microorganism) based on either well-established isolation or bioinformatic pipelines. Moreover, computer-assisted strategies (e.g., machine learning (ML) and deep learning (DL)) have emerged as a powerful and promising technology for the accurate prediction and design of new AMPs. It may overcome some of the shortcomings of traditional antibiotic discovery and contribute to the rapid development and translation of AMPs. In these cases, this review aims to appraise the latest advances in identifying and designing AMPs and their significant antimicrobial activities against a wide range of bacterial pathogens. The review also highlights the critical challenges in discovering and applying AMPs.

A Comparative Evaluation of the Antimicrobial Properties of 50% Grape Seed Extract, N-acetyl Cysteine and 5.25% Sodium Hypochlorite against Enterococcus faecalis (ATCC 19433) – An In vitro Study

Abstract Introduction: Endodontic infections are complex and polymicrobial, presenting significant challenges in dental treatment. Eliminating bacteria is the main objective of endodontic preparation, ensuring a tight seal to prevent reinfection. A commonly isolated bacterium, Enterococcus faecalis, is Gram positive and facultative anaerobic. It thrives in low-nutrient environments, forming resilient biofilms. Due to its tissue dissolving properties and broad-spectrum antimicrobial, sodium hypochlorite (NaOCl) is the most sought after irrigant, but its cytotoxicity is a concern. Alternatives such as grape seed extract (GSE) and N-acetyl cysteine (NAC) are being explored for their potential antimicrobial effects and biocompatibility. Materials and Methods: Forty single-rooted, non-carious premolars extracted for orthodontic reasons were selected. Teeth were cleaned, sectioned and prepared, ensuring apical patency. Specimens were autoclaved and contaminated with E. faecalis (ATCC 19433) for 30 days. Four groups (n = 10) were formed: Group I – GSE 50%, Group II – NAC 200 mg/ml, Group III – NaOCl 5.25% and Group IV – sodium chloride (0.9%). Manufacturer’s instructions were followed precisely to prep the solutions, and root canals were treated using the Reciproc R25 instrument. Samples were collected before (F1) and after (F2) instrumentation and irrigation. Colony-forming units (CFUs) were quantified and analysis was done using two-way analysis of variance and Tukey’s honestly significant difference post hoc tests, with significance set at P < 0.05. Results: NaOCl significantly reduced CFU counts, demonstrating superior antimicrobial efficacy compared to NAC and GSE (P < 0.01). In comparison to negative control and GSE (P < 0.01), NAC showed significant antimicrobial activity, but not significantly different from GSE (P > 0.05). GSE displayed potential antimicrobial properties but was less effective than NaOCl and NAC. Conclusion: NaOCl remains the most effective irrigant; however, NAC and GSE also demonstrated significant antimicrobial properties and could serve as adjuncts in endodontic therapy. Further research is needed to optimise their formulations and validate clinical applications.

Characteristics and in vitro properties of potential probiotic strain Fructobacillus tropaeoli KKP 3032 isolated from orange juice.

Fructobacillus, a Gram-positive, non-spore-forming, facultative anaerobic bacterium, belongs to the fructophilic lactic acid bacteria (FLAB) group. The group's name originates from fructose, the favored carbon source for its members. Fructobacillus spp. are noteworthy for their distinctive traits, captivating the interest of scientists. However, there have been relatively few publications regarding the isolation and potential utilization of these microorganisms in the industry. In recent years, F. tropaeoli has garnered interest for its promising role in the food and pharmaceutical sectors, although the availability of isolates is rather limited. A more comprehensive understanding of Fructobacillus is imperative to evaluate their functionality in the industry, given their unique and exceptional properties. Our in vitro study on Fructobacillus tropaeoli KKP 3032 confirmed its fructophilic nature and high osmotolerance. This strain thrives in a 30% sugar concentration, shows resistance to low pH and bile salts, and exhibits robust autoaggregation. Additionally, it displays significant antimicrobial activity against foodborne pathogens. Evaluating its probiotic potential, it aligns with EFSA recommendations in antibiotic resistance, except for kanamycin, to which it is resistant. Further research is necessary, but preliminary analyses confirm the high probiotic potential of F. tropaeoli KKP 3032 and its ability to thrive in the presence of high concentrations of fructose. The results indicate that the isolate F. tropaeoli KKP 3032 could potentially be used in the future as a fructophilic probiotic, protective culture, and/or active ingredient in fructose-rich food.

Reconstruction of the Reaction of Andalusicin Lantibiotic Modification by Lanthionine Synthetase AncKC in a Heterologous Escherichia coli System.

The increasing resistance of microorganisms to antibiotics makes it a necessity that we search for new antimicrobial agents. Due to their genetically encoded nature, peptides are promising candidates for new antimicrobial drugs. Lantipeptide andalusicin exhibits significant antimicrobial activity against Gram-positive bacteria, making it a promising scaffold for the development of DNA-encoded libraries of lantibiotics. In this study, the modification reaction of andalusicin by class III lanthionine synthetase AncKC was reconstructed in a heterologous Escherichia coli system. The results obtained open possibilities for creating novel peptide- based antimicrobial agents.

Antimicrobial, Antifungal, and Insecticidal Activities of Scolymus Grandiflorus Essential Oil Rich in Davanoid Compounds

Background: This study explores the antimicrobial, antifungal, and insecticidal properties of Scolymus grandiflorus essential oil, examining its potential uses in the fields of pharmacology and agriculture. Materials and Methods: The essential oil obtained by hydrodistillation was studied by GC and GC/MS. The antibacterial capacity of the essential oil was determined against two Gram-positive and three Gram-negative bacterial species. The antifungal activity of the essential oil was investigated against two fungi responsible for many fruit and vegetable diseases. The insecticidal activity of essential oil was evaluated against larvae, pupae, and adult flies of Ceratitis capitata. Results: The GC and GC-MS analysis of the essential oil of the roots of S. grandiflorus revealed the predominant presence of davanoids, representing more than 80% of its chemical composition. The results of the disc diffusion test showed significant antimicrobial activity. The essential oil inhibited the growth of Salmonella typhi (25 mm), Staphylocoque aureus (18 mm), and Escherichia coli (17 mm), with inhibition diameters comparable to those of gentamicin. The essential oil significantly inhibited mycelial growth, with up to 98% inhibition for Fusarium solani and 73% for Alternaria alternata at 8 μL/mL. Insecticidal activity was most pronounced on adult flies, followed by pupae and finally larvae. Conclusion: Tests on the essential oils of S. grandiflorus revealed promising characteristics as insecticidal, antifungal, and antimicrobial agents. These results could be used in the development of new solutions to control pathogens responsible for plant diseases and mycotoxin-producing organisms.

Novel Imine Complexes Incorporating ZrO(II), VO(II), and Pd(II) Cations: Synthesis, DFT Calculation, Molecular Docking, Antimicrobial, and Antitumor Activity

ABSTRACTNovel imine complexes of ZrO(II), VO(II), and Pd(II) have been synthesized and described using IR, TGA, UV/Vis, and 1HNMR methods, along with powder X‐ray diffraction (XRD), elemental (CHN) analysis, mass spectrometry, molar conductance, and magnetic susceptibility measurements. Conductivity measurements indicate that none of the complexes function as electrolytes. Magnetic susceptibility data confirm the paramagnetism of the VO(II) complex, while ZrO(II) and Pd(II) complexes exhibit diamagnetic properties. Various analyses suggest that divalent cations favor a 1:1 metal‐to‐ligand ratio. Biological studies demonstrated that all complexes possess significant antimicrobial activity against a range of bacterial and fungal strains. We also observed that the antimicrobial potency of the metal complexes follows the order: ZrO(II) > Pd(II) > VO(II) > H2A, with the ZrO(II) complex showing the highest inhibition zone (28 mm) against Gram‐negative bacteria. The antifungal activity against Aspergillus flavus increases in the order VO(II) > ZrO(II) > Pd(II) > H2A. Additionally, the complexes exhibit high cytotoxicity against carcinoma cell lines, including the HepG‐2, when compared with the clinically proven vinblastine. Density functional theory (DFT) calculations were performed to elucidate the equilibrium geometry of the imine ligand and its complexes at the B3LYP level of theory, using the Gaussian 09 program with 6‐311G++(dp) basis set for C, H, O, N, and Cl atoms, and lanl2dz for Pd, V, and Zr atoms. Finally, docking studies revealed potential binding modes at the active sites of bacterial and fungal receptors.

Comprehensive evaluation of the antibacterial and antibiofilm activities of NiTi orthodontic wires coated with silver nanoparticles and nanocomposites: an in vitro study.

Fixed orthodontic appliances act as a niche for microbial growth and colonization. Coating orthodontic wires with antimicrobial silver nanoparticles (AgNPs) and nanocomposite was adopted in this study to augment the biological activity of these wires by increasing their antibacterial and antibiofilm properties and inhibiting bacterial infections that cause white spot lesions and lead to periodontal disease. Three concentrations of biologically synthesized AgNPs were used for coating NiTi wires. The shape, size, and charge of the AgNPs were determined. Six groups of 0.016 × 0.022-inch NiTi orthodontic wires, each with six wires, were used; and coated with AgNPs and nanocomposites. The antimicrobial and antibiofilm activities of these coated wires were tested against normal flora and multidrug-resistant bacteria (Gram-positive and Gram-negative bacterial isolates). The surface topography, roughness, elemental percentile, and ion release were characterized. AgNPs and nanocomposite coated NiTi wires showed significant antimicrobial and antibiofilm activities. The chitosan-silver nanocomposite (CS-Ag) coated wires had the greatest bacterial growth inhibition against both Gram-positive and Gram-negative bacteria. The surface roughness of the coated wires was significantly reduced, impacting the surface topography and with recorded low Ni and Ag ion release rates. NiTi orthodontic wires coated with AgNPs, and nanocomposites have shown increased antimicrobial and antibiofilm activities, with decreased surface roughness, friction resistance and limited- metal ion release.

THE ROLE OF NOVEL PROBIOTIC STRAINS IN ENHANCING IMMUNITY AND PREVENTING INFECTIONS IN LIVESTOCK: A COMPREHENSIVE REVIEW

The use of probiotics in animal production has become increasingly important due to growing concerns about antimicrobial resistance and the pursuit of sustainable farming practices. This study aimed to explore the role of novel probiotic strains in enhancing immunity and preventing infections in livestock. We conducted a systematic literature review following PRISMA guidelines and used the PICO model to formulate the research question. The results indicated that various probiotic strains, such as Lactobacillus fermentum, Enterococcus faecium, Lactobacillus rhamnosus, Lactobacillus gasseri, and Bacillus subtilis, showed significant antimicrobial and immunomodulatory activities. These strains improved nutrient digestibility, reduced disease incidence, and increased the production of immunoglobulins and anti-inflammatory cytokines. We conclude that probiotics have significant potential as an alternative to antibiotics in livestock production, promoting safer and more sustainable agricultural practices.

Identification and synthesis of a long-chain antimicrobial peptide from the venom of the Liocheles australasiae scorpion.

Scorpion venom contains linear peptides without disulfide bonds in addition to peptides with disulfide bonds. Many such linear peptides have an amphiphilic α-helical structure, often with antimicrobial activity and can be classified into three groups based on their molecular size. Among them, long-chain antimicrobial peptides consisting of more than 40 residues have not been thoroughly studied due to the difficulty of synthesizing them. We have previously reported a transcriptome analysis of the venom gland of Liocheles australasiae that revealed precursor sequences of long-chain antimicrobial peptides. In the study reported here, we identified the mature structure of one such long-chain antimicrobial peptide, LaCT1, which we synthesized using chemical ligation to confirm its structure and evaluate its biological activities. The result showed that LaCT1 exhibited significant antimicrobial activity. In addition, we identified its partial peptides consisting of an N- or C-terminal region, which may be generated by enzymatic cleavage in the venom. Among them, only the peptide containing the N-terminal half region was active. LaCT1 also not only showed insecticidal activity but also synergistically enhanced the effects of another insecticidal peptide identified in L. australasiae venom as well. These results provide insights into the role of antimicrobial peptides in scorpion venom.

Synergistic Action of Rutin-Coated Zinc Oxide Nanoparticles: Targeting Biofilm Formation Receptors of Dental Pathogens and Modulating Apoptosis Genes for Enhanced Oral Anticancer Activity.

Oral diseases are often associated with bacterial and fungal pathogens such as Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans. This research explored a novel approach to addressing these pathogens by synthesizing zinc oxide nanoparticles (ZnO NPs) coated with rutin (RT), a plant-derived compound. The synthesized ZnO-RT NPs were comprehensively characterized using UV-Vis spectrophotometer, SEM, and EDAX techniques to confirm their structural composition. The antioxidant potential was assessed through free radical scavenging assays. Additionally, the antimicrobial activity of ZnO-RT NPs was evaluated using a zone of inhibition assay against oral pathogens. Molecular docking studies with the Autodock tool were performed to elucidate the interactions between RT and the receptors of oral pathogens. The findings demonstrated that ZnO-RT NPs exhibited robust free radical scavenging activity. Furthermore, they showed significant antimicrobial activity with a minimal inhibitory concentration of 40 μg/mL against oral pathogens. ZnO-RT NPs also displayed dose-dependent anticancer effects on human oral cancer cells at concentrations of 10, 20, 40, and 80 μg/mL. Mechanistic insights into the anticancer activity on KB cells revealed the upregulation of apoptotic genes. This study underscores the promising potential of ZnO-RT NPs for dental applications due to their strong antioxidant, anticancer, and antimicrobial properties. These nanoparticles offer a hopeful prospect for addressing oral pathogen challenges and enhancing overall oral health.

Antimicrobial peptide LyeTx I mn∆K labeled with 68Ga is a potential PET radiopharmaceutical for molecular imaging of infections

BackgroundAntimicrobial peptides have been radiolabeled and investigated as molecular diagnostic probes due to their propensity to accumulate in infectious sites rather than aseptic inflammatory lesions. LyeTx I is a cationic peptide from the venom of Lycosa erythrognatha, exhibiting significant antimicrobial activity. LyeTx I mn∆K is a shortened derivative of LyeTx I, with an optimized balance between antimicrobial and hemolytic activities. This study reports the first 68Ga-radiolabeling of the DOTA-modified LyeTx I mn∆K and primarily preclinical evaluations of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a PET radiopharmaceutical for infection imaging. MethodsDOTA(K)-LyeTx I mn∆K was radiolabeled with freshly eluted 68Ga. Radiochemical yield (RCY), radiochemical purity (RCP), and radiochemical stability (in saline and serum) were evaluated using ascending thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC). The radiopeptide's lipophilicity was assessed by determining the logarithm of the partition coefficient (Log P). Serum protein binding (SBP) and binding to Staphylococcus aureus (S. aureus) cells were determined in vitro. Ex vivo biodistribution studies and PET/CT imaging were conducted in healthy mice (control) and mice with infection and aseptic inflammation to evaluate the potential of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a specific PET radiopharmaceutical for infections. Results[68Ga]Ga-DOTA(K)-LyeTx I mn∆K was obtained with a high RCY (>90 %), and after purification through a Sep-Pak C18 cartridge, the RCP exceeded 99 %. Ascending TLC and RP-HPLC showed that the radiopeptide remained stable for up to 3.0 h in saline solution and up to 1.5 h in murine serum. [68Ga]Ga-DOTA(K)-LyeTx I mn∆K exhibited hydrophilic characteristics (Log P = −2.4 ± 0.1) and low SPB (ranging from 23.3 ± 0.4 % at 5 min of incubation to 10.5 ± 1.1 % at 60 min of incubation). The binding of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K to S. aureus cells was proportional to bacterial concentration, with binding percentages of 8.8 ± 0.5 % (0.5 × 109 CFU.mL−1), 16.2 ± 1.4 % (1.0 × 109 CFU.mL−1), and 62.2 ± 0.6 % (5.0 × 109 CFU.mL−1). Ex vivo biodistribution studies and PET/CT images showed higher radiopeptide uptake at the infection site compared to the aseptic inflammation site; the latter was similar to the control group. Target-to-non-target (T/NT) ratios obtained by ex vivo biodistribution data were approximately 1.0, 1.3, and 3.0 at all investigated time intervals for the control, aseptic inflammation, and infection groups, respectively. Furthermore, T/NT ratios obtained from PET/CT images were 1.1 ± 0.1 for the control group and 1.4 ± 0.1 for the aseptic inflammation group. For the infection group, T/NT ratio was 5.0 ± 0.3, approximately 5 times greater compared to the former groups. ConclusionsThe results suggest the potential of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a PET radiopharmaceutical for molecular imaging of infections.

Biocompatible Zn-Phthalocyanine/Gelatin Nanofiber Membrane for Antibacterial Therapy.

In this study, the fabrication and characterization of Zn-phthalocyanine/gelatin nanofibrous membranes is reported using the electrospinning technique. The membranes exhibit a homogeneous distribution of Zn-phthalocyanine within the gelatin matrix, maintaining the structural integrity and photosensitizing properties of the phthalocyanine. Scanning electron microscopy revealed that the electrospun fibers possess diameters ranging results as 100-300, 200-700, and 300-800nm for Gel, ZnPc/Gel 1, and ZnPc/Gel 2, respectively. The addition of ZnPc does not decrease the hydrophilicity of the Gel membrane. The nanofibrous membranes showed good cytocompatibility, as indicated by the high viability of Vero cells exposed to membrane extracts. Furthermore, these composites supported cell adhesion and proliferation on their surfaces. The two Zn-phthalocyanine/gelatin nanofiber formulations exhibited significant antimicrobial activity toward Escherichia Coli (E. Coli) and Staphylococcus Aureus (S. Aureus) under visible light illumination, achieving reductions of 3.4 log10 and 3.6 log10 CFUmL-1 for E. coli, and 3.9 log10 and 4.1 log10 CFUmL-1 for S. aureus. These results demonstrate the potential of Zn-phthalocyanine/gelatin nanofibrous membranes as effective agents in antibacterial photodynamic therapy, providing a promising solution to control bacterial infections and antibiotic resistance.

One-pot synthesis of new benzo[4,5]imidazo[1,2-a]pyrimidines and pyrazolo[1,5-a] pyrimidines as an eco-friendly and effective method catalyzed by acetic acid with prospective antimicrobial agents

A novel set chalcones 3a-d was efficiently synthesized in elevated produces across the condensing process of Claisen-Schmidt. An eco-friendly and efficient process was designed for creating a novel desired products 5a-f and 7a-f, respectively with excellent yields. This synthesis was accomplished by reacting acetophenone derivatives 1a-d, heteroaromatic aldehydes 2a,b and aminobenzoimidazole 4 or 3-aminopyrazole 6a,b, using acetic acid as both the catalyst and solvent. Solvent optimization was performed during the synthesis of the desired compounds 5a or 7a, highlighting the benefits of using acetic acid that is harmless for the environment, which offers easy procedure, rapid reaction, elevated efficiency and broad tolerance of starting materials. The preferred products were verified through compatible spectroscopic data. The antimicrobial efficacious for all compounds was successfully evaluated against various microorganisms, revealing that 3b exhibited significant antimicrobial activity across all tested microbes, with measurements of the minimum inhibitory concentrations being between 4.80 to 63.8 μM.

Green-synthesis of silver nanoparticles AgNPs from Podocarpus macrophyllus for targeting GBM and LGG brain cancers via NOTCH2 gene interactions

Brain tumors, particularly Glioblastoma Multiforme (GBM) and Low-Grade Gliomas (LGG), present significant clinical challenges due to their aggressive nature and resistance to conventional treatments. Traditional therapies such as surgery, chemotherapy, and radiation are often limited in efficacy, necessitating novel therapeutic strategies. Nanotechnology, particularly the use of silver nanoparticles (Ag NPs), offers a targeted and potentially more effective approach. This study focuses on the green synthesis of Ag NPs using Podocarpus macrophyllus leaf extract as a reducing agent. The synthesized Ag NPs were characterized for their physicochemical properties, demonstrating a controlled particle size of 13 nm as determined by scanning electron microscopy (SEM). Fourier-transform infrared (FTIR) spectroscopy confirmed the presence of functional groups, and energy-dispersive X-ray (EDX) spectroscopy revealed that silver constituted approximately 90% of the nanoparticle composition. The Ag NPs exhibited promising biological activity, including 90% free radical scavenging (antioxidant) activity, 99.15% inhibition of protein denaturation (anti-inflammatory activity), and 90.56% inhibition of alpha-amylase (anti-diabetic activity). Additionally, the nanoparticles displayed significant anti-hemolytic (89.9% inhibition) and antimicrobial activities, with a 20 mm inhibition zone against Staphylococcus species. Computational analyses further indicated that the NOTCH2 gene, which is upregulated in LGG and GBM, may interact with Ag NPs, suggesting their potential in brain cancer therapy. The green synthesis approach offers a sustainable and bioactive method for producing Ag NPs, underscoring their therapeutic promise for treating GBM and LGG.

Unveiling the chemical composition, antioxidant and antibacterial properties, and mechanistic insights of Convolvulus arvensis extract through molecular docking simulations

The use of herbal extracts has gained significant importance in modern health practices, making it essential to explore their properties and applications in detail. This study investigates the effect of ultrasound on the extraction yield of Convolvulus arvensis leaves, with a focus on its chemical composition, antioxidant properties, cytotoxicity, antimicrobial activities, and mechanism of action. Antimicrobial activity was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), well diffusion agar, and disk diffusion agar assays. The antioxidant properties were assessed through ferric reducing antioxidant power (FRAP) and DPPH free radical scavenging assays. High Performance Liquid Chromatography (HPLC) and Fourier transform infrared (FTIR) spectroscopy were utilized to identify the chemical composition and functional groups present in the extract. The findings revealed that ultrasound-assisted extraction exhibited significantly higher extraction efficiency (p < 0.05). The extract displayed significant antimicrobial activity against Listeria innocua, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The total phenolic and total flavonoid contents of the extract were measured at 328.85 ± 0.046 (mg GAE/100 g) and 226.23 ± 0.043 (mg QE/100 g), respectively. Moreover, the extract demonstrated notable radical scavenging activity against DPPH, with a value of 37.40 ± 0.111 (g/100 g). The FRAP assay revealed that the antioxidant activity of C. arvensis extract was quantified at 23.796 ± 0.045 μmol Fe²⁺. The highest amount of phenolic and alkaloid compounds in the extract was related to β-Phellandrene (341.52 µg/mL) and Swainsonine (360.24 µg/mL), respectively. Furthermore, the in vitro cytotoxic activity of the extract was evaluated against the Caco-2 cell line, with the IC50 value determined to be 26.55 mg/mL. The results of the docking study demonstrated that Ferulic acid displayed a significant binding energy of −6.2 kcal/mol, suggesting a robust interaction with the target enzyme and the potential to act as a modulator of glutathione peroxidases. The findings of the present study revealed that the alcoholic extract of C. arvensis possesses proper antioxidant and antimicrobial activities. Therefore, it has been used as a food preservative. However, further medical and clinical researches are required before any application in human health.

Visible Light-Sensitive Sustainable Quantum Dot Crystals of Co/Mg Doped Natural Hydroxyapatite Possessing Antimicrobial Activity and Biocompatibility.

Cutting-edge research in advanced materials is increasingly turning toward the development of novel multifunctional nanomaterials for use in high-tech applications. This research uses the solid-state method as a solvent-free technique to create multifunctional quantum dot (QD) hydroxyapatite (HA) crystals from bovine bone waste. By incorporating cobalt (Co) and magnesium (Mg) into the HA structure, the crystallinity of the hexagonal HA nanoparticles (99.7%), showing QD crystals is enhanced. Oxygen vacancies on the surfaces of the HA nanoparticles contributed to their bandgap falling within the visible light range. In addition, the dopants substituted calcium in the HA crystal structure and generated a divalent oxidation state, shifting the bandgap of natural HA toward red wavelengths (3.26 to 1.94eV). Moreover, the incorporation of Co led to magnetization within the HA structure through spin polarization. Additionally, the doped QD crystals of HA nanoparticles showed significant antimicrobial activity against Escherichia coli, Staphylococcus aureus, and bacteriophages MS2, particularly under visible light exposure. In short, the Co/Mg co-doped HA nanoparticles exhibited ferromagnetic properties, sensitivity to visible light, biocompatibility, and considerable antimicrobial effects, establishing their potential as sustainable multifunctional materials for biomedical applications, especially in anti-infection treatments.

Effect of Oxidation of the Hydroalcoholic Extract of Myracrodruon urundeuva All. (Anarcadiaceae) on its Antimicrobial Activity

This study investigates the relaction between oxidation and antimicrobial activity of the hydroalcoholic extract of Myracrodruon urundeuva, a plant known for its traditional medicinal uses. The primary objective was to evaluate how the oxidation of bioactive compounds within the extract affects its antimicrobial efficacy against common pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The extract was prepared following a standardized methodology, and its antimicrobial properties were assessed using disk diffusion assays over a 60-day period, with samples tested every 15 days to monitor changes in activity. The results revealed that the extract exhibited significant antimicrobial activity, particularly at higher concentrations (100%~50%), with inhibition zones reaching up to 16.7 mm against Staphylococcus aureus by day 30. However, a notable decline in activity was observed between days 30 and 45, indicating a potential degradation of the extract's efficacy over time. Interestingly, lower concentrations (12.5% and 0.4%) showed a resurgence in inhibitory activity towards the end of the study, suggesting that certain oxidative processes may enhance the antimicrobial properties of specific compounds. The study highlights the complex relationship between oxidation and antimicrobial activity demonstrating that certain compounds lose effectiveness, while others become more potent after oxidative modification. This finding is particularly relevant in the context of increasing bacterial resistance to conventional antibiotics, as it suggests that the oxidation of plant-derived compounds could be a viable strategy to enhance their antimicrobial properties. Overall, this research underscores the potential of Myracrodruon urundeuva as a natural alternative in combating resistant pathogens and emphasizes the need for further investigation into the mechanisms by which oxidation influences the activity of bioactive compounds in medicinal plants.

Chemical characterization, antimicrobial and mosquito larvicidal activities of the essential oil of Camellia pleurocarpa (Gagnep.) Sealy from Vietnam

Camellia pleurocarpa (Gagnep.) Sealy, a species of yellow camellia indigenous to Vietnam, was investigated for its essential oil properties in this study. Hydrodistillation of its leaves yielded a complex mixture rich in sesquiterpenes and diterpenes. Chemical analysis identified 50 constituents, with notable compounds including spathulenol (13.26%), phytol (9.94%), and α-selinene (5.34%). The essential oil exhibited significant antimicrobial activity against three Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus; one Gram-negative bacterium Pseudomonas aeruginosa; and one yeast Candida albicans, with minimum inhibitory concentration (MIC) values ranging from 16 to 32 μg/mL and half-maximal inhibitory concentration (IC50) values ranging from 7.26 to 16.23 μg/mL. Furthermore, it demonstrated larvicidal potential against Aedes aegypti and Culex quinquefasciatus mosquitoes, with LC50 values ranging from 13.49 to 28.95 μg/mL and LC90 values ranging from 28.29 to 53.24 μg/mL. These findings underscore the promising antimicrobial and mosquito larvicidal properties of C. pleurocarpa essential oil, suggesting its potential as a natural alternative in combating microbial infections and controlling mosquito-borne diseases. This study represents the first comprehensive report on the chemical compositions and bioactivities of C. pleurocarpa essential oil.

Discovering bioactive phytoconstituents from Citrullus lanatus for antimicrobial and antioxidants therapeutic applications

In recent decades, significant interest in natural bioactive compounds has led many researchers to study plants as primary natural sources of bioactive compounds, mainly when considering a few biological properties, including antioxidant, antimicrobial, and anti-inflammatory activities, and as nutritional supplements with health benefits. We designed this study to explore the phytochemicals profiling of Citrallus lanatus and evaluate their in vitro bioactive properties. The methanol extraction of the watermelon's stem, rind, and leaf parts through Soxhlet extraction was analyzed using Gas Chromatography-Mass Spectrometry. The GC-MS profiling of Citrullus lanatus examines the presence of numerous bioactive phytoconstituents with potential biological activities such as antioxidant, anti-inflammatory, antimicrobial, anticancer, and other properties. We have evidenced that the stem, rind, and leaf extracts with significant antioxidant and antimicrobial activities against clinically relevant pathogens like Salmonella typhi, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. Overall, our study sheds light on exploring novel bioactive phytoconstituents from Citrullus lanatus and explore, harness these compounds' therapeutic potential for human health.

Psychiatric disorders associated with fluoroquinolones: a pharmacovigilance analysis of the FDA adverse event reporting system database.

Fluoroquinolones are broad-spectrum antibiotics with significant antimicrobial activity. Despite their therapeutic benefits, they are associated with a range of adverse drug reactions (ADRs), particularly those affecting the central nervous system (CNS). This study aimed to analyze the psychiatric ADRs linked to fluoroquinolones using data from the FDA Adverse Event Reporting System (FAERS) database. A retrospective pharmacovigilance study was conducted using FAERS data from Q1 2004 to Q4 2023. The data processing phase involved the FDA-recommended deduplication method, and ADRs were classified according to Medical Dictionary for Regulatory Activities (MedDRA). Disproportionality analysis was performed using the reporting odds ratio (ROR), and statistical significance was assessed using the Chi-square test or Fisher's exact test. The study identified 84,777 reports associated with fluoroquinolones, with 359,480 Preferred Terms-annotated entries, 27,816 of these reports were psychiatric ADRs. Mood disorders were the most frequently reported, including anxiety, depression, and delirium, with some reports escalating to suicidal ideation and behaviors. The Standardized MedDRA Query classification system was used to categorize these ADRs into Depression, Suicide/self-injury, Psychosis and psychotic disorders, and Non-infectious encephalopathy/delirium. Ciprofloxacin was most frequently linked to depression and suicidal ideation, while moxifloxacin showed a robust correlation with delirium. The risk of psychiatric ADRs varied by age group, with affective disorders more prevalent in adults under 65 and psychosis and delirium in those over 65. Fluoroquinolones are associated with a range of psychiatric ADRs, with notable differences between the drugs in the class. The study highlights the need for caution in prescribing fluoroquinolones, particularly for patients with pre-existing mental health conditions or those in higher risk age groups. The findings also underscore the importance of considering age-specific preventive strategies when administering these antibiotics.