Antibacterial Properties Research Articles

Copper Oxide Electrochemical Deposition to Create Antiviral and Antibacterial Nanocoatings.

The impact of the reaction environment on the formation of the polycrystalline layer and its biomedical (antimicrobial) applications were analyzed in detail. Copper oxide layers were synthesized using an electrodeposition technique, with varying additives influencing the morphology, thickness, and chemical composition. Scanning electron microscopy (SEM) images confirmed the successful formation of polyhedral structures. Unmodified samples (CuL) crystallized as a mixture of copper oxide (I) and (II), with a thickness of approximately 1.74 μm. The inclusion of the nonconductive polymer polyvinylpyrrolidone (PVP) during synthesis led to a regular and compact CuO-rich structure (CuL-PVP). Conversely, adding glucose resulted in forming a Cu2O-rich nanostructured layer (CuL-D(+)G). Both additives significantly reduced the sample thickness to 617 nm for CuL-PVP and 560 nm for CuL-D(+)G. The effectiveness of the synthesized copper oxide layers was demonstrated in their ability to significantly reduce the T4 phage titer by approximately 2.5-3 log. Notably, CuL-PVP and CuL-D(+)G showed a more substantial reduction in the MS2 phage titer, achieving about a 5-log decrease. In terms of antibacterial activity, CuL and CuL-PVP exhibited moderate efficacy against Escherichia coli, whereas CuL-D(+)G reduced the E. coli titer to undetectable levels. All samples induced similar reductions in Staphylococcus aureus titer. The study revealed differential susceptibilities, with Gram-negative bacteria being more vulnerable to CuL-D(+)G due to its unique composition and morphology. The antimicrobial properties were attributed to the redox cycling of Cu ions, which generate ROS, and the mechanical damage caused by nanostructured surfaces. A crucial finding was the impact of surface composition rather than surface morphology on antimicrobial efficacy. Samples with a dominant Cu2O composition exhibited potent antibacterial and antiviral properties, whereas CuO-rich materials showed predominantly enhanced antiviral activity. This research highlights the significance of phase composition in determining the antimicrobial properties of copper oxide layers synthesized through electrodeposition.

A 2D nanoflower-like ordered mesoporous Bi12ZnO20 catalyst with excellent photocatalytic antibacterial properties.

The flower-shaped photocatalytic material Bi12ZnO20, consisting of nanoparticles, was successfully synthesized in this study. Rigorous antibacterial experiments were conducted on various fungi using the material, yielding excellent results. Furthermore, the application of this material for antibacterial treatment of livestock and poultry manure sewage in real-life scenarios demonstrated remarkable efficacy.

Evaluation of the Antibacterial, Anti-Inflammatory, And Bone-Promoting Capacity of UiO-66 Loaded with Thymol or Carvacrol.

Oral infectious diseases have a significant impact on the health of oral and maxillofacial regions, as well as the overall well-being of individuals. Carvacrol and thymol, two isomers known for their effective antibacterial and anti-inflammatory properties, have gained considerable attention in the treatment of oral infectious diseases. However, their application as topical drugs for oral use is limited due to their poor physical and chemical stability. UiO-66, a metal-organic framework based on zirconium ion (Zr4+), exhibits high drug loading capability. Carvacrol and thymol were efficiently loaded onto UiO-66 with loading rates of 79.60 ± 0.71% and 79.65 ± 0.76%, respectively. The release rates of carvacrol and thymol were 77.82 ± 0.87% and 76.51 ± 0.58%, respectively, after a period of 72 h. Moreover, Car@UiO-66 and Thy@UiO-66 demonstrated excellent antibacterial properties against Candida albicans, Escherichia coli, and Staphylococcus aureus with minimum bactericidal concentrations (MBC) of 0.313 mg/mL, 0.313 mg/mL, and 1.25 mg/mL, respectively. Furthermore, based on the results of the CCK8 cytotoxicity assay, even at concentrations as high as 1.25 mg/mL, Car@UiO-66 and Thy@UiO-66 exhibited excellent biocompatibility with a relative cell survival rate above 50%. These findings suggest that Car@UiO-66 and Thy@UiO-66 possess favorable biocompatibility properties without significant toxicity towards periodontal membrane cells. Additionally, in vivo studies confirmed the efficacy of Car@UiO-66and Thy@UiO-66 in reducing inflammation, promoting bone formation through inhibition of TNF-a and IL6 expression, enhancement of IL10 expression, and acceleration of bone defect healing. Therefore, the unique combination of antibacterial, anti-inflammatory, and osteogenic properties make Car@UiO-66 and Thy@Ui O-66 promising candidates for the treatment of oral infectious diseases and repairing bone defects.

Antibacterial and antibiofilm potentials of vancomycin-loaded niosomal drug delivery system against methicillin-resistant Staphylococcus aureus (MRSA) infections.

The threat of methicillin-resistant Staphylococcus aureus (MRSA) is increasing worldwide, making it significantly necessary to discover a novel way of dealing with related infections. The quick spread of MRSA isolates among infected individuals has heightened public health concerns and significantly limited treatment options. Vancomycin (VAN) can be applied to treat severe MRSA infections, and the indiscriminate administration of this antimicrobial agent has caused several concerns in medical settings. Owing to several advantageous characteristics, a niosomal drug delivery system may increase the potential of loaded antimicrobial agents. This work aims to examine the antibacterial and anti-biofilm properties of VAN-niosome against MRSA clinical isolates with emphasis on cytotoxicity and stability studies. Furthermore, we aim to suggest an effective approach against MRSA infections by investigating the inhibitory effect of formulated niosome on the expression of the biofilm-associated gene (icaR). The thin-film hydration approach was used to prepare the niosome (Tween 60, Span 60, and cholesterol), and field emission scanning electron microscopy (FE-SEM), an in vitro drug release, dynamic light scattering (DLS), and entrapment efficiency (EE%) were used to investigate the physicochemical properties. The physical stability of VAN-niosome, including hydrodynamic size, polydispersity index (PDI), and EE%, was analyzed for a 30-day storage time at 4°C and 25°C. In addition, the human foreskin fibroblast (HFF) cell line was used to evaluate the cytotoxic effect of synthesized niosome. Moreover, minimum inhibitory and bactericidal concentrations (MICs/MBCs) were applied to assess the antibacterial properties of niosomal VAN formulation. Also, the antibiofilm potential of VAN-niosome was investigated by microtiter plate (MTP) and real-time PCR methods. The FE-SEM result revealed that synthesized VAN-niosome had a spherical morphology. The hydrodynamic size and PDI of VAN-niosome reported by the DLS method were 201.2nm and 0.301, respectively. Also, the surface zeta charge of the prepared niosome was - 35.4 mV, and the EE% ranged between 58.9 and 62.5%. Moreover, in vitro release study revealed a sustained-release profile for synthesized niosomal formulation. Our study showed that VAN-niosome had acceptable stability during a 30-day storage time. Additionally, the VAN-niosome had stronger antibacterial and anti-biofilm properties against MRSA clinical isolates compared with free VAN. In conclusion, the result of our study demonstrated that niosomal VAN could be promising as a successful drug delivery system due to sustained drug release, negligible toxicity, and high encapsulation capacity. Also, the antibacterial and anti-biofilm studies showed the high capacity of VAN-niosome against MRSA clinical isolates. Furthermore, the results of real-time PCR exhibited that VAN-niosome could be proposed as a powerful strategy against MRSA biofilm via down-regulation of icaR gene expression.

A Microenvironment-Responsive, Controlled Release Hydrogel Delivering Embelin to Promote Bone Repair of Periodontitis via Anti-Infection and Osteo-Immune Modulation.

Periodontitis, a prevalent chronic inflammatory disease, poses significant challenges for effective treatment due to its complex etiology involving specific bacteria and the inflammatory immune microenvironment. Here, this study presents a novel approach for the targeted treatment of periodontitis utilizing the immunomodulatory and antibacterial properties of Embelin, a plant-derived compound, within an injectable hydrogel system. The developed Carboxymethyl Chitosan-Oxidized Dextran (CMCS-OD) hydrogel formed via dynamic chemical bonds exhibited self-healing capabilities and pH-responsive behavior, thereby facilitating the controlled release of Embelin and enhancing its efficacy in a dynamic oral periodontitis microenvironment. This study demonstrates that this hydrogel system effectively prevents bacterial invasion and mitigates excessive immune response activation. Moreover, it precisely modulates macrophage M1/M2 phenotypes and suppresses inflammatory cytokine expression, thereby fostering a conducive environment for bone regeneration and addressing periodontitis-induced bone loss. These findings highlight the potential of the approach as a promising strategy for the clinical management of periodontitis-induced bone destruction.

A Highly Stable, Multifunctional Janus Dressing for Treating Infected Wounds.

The limited and unstable absorption of excess exudate is a major challenge during the healing of infected wounds. In this study, a highly stable, multifunctional Janus dressing with unidirectional exudate transfer capacity is fabricated based on a single poly(lactide caprolactone) (PLCL). The success of this method relies on an acid hydrolysis reaction that transforms PLCL fibers from hydrophobic to hydrophilic in situ. The resulting interfacial affinity between the hydrophilic/phobic PLCL fibers endows the Janus structure with excellent unidirectional liquid transfer and high structural stability against repeated stretching, bending, and twisting. Various other functions, including wound status detection, antibacterial, antioxidant, and anti-inflammatory properties, are also integrated into the dressing by incorporating phenol red and epigallocatechin gallate. An in vivo methicillin-resistant Staphylococcus aureus-infected wound model confirms that the Janus dressing, with the capability to remove exudate from the infected site, not only facilitates epithelialization and collagen deposition, but also ensures low inflammation and high angiogenesis, thus reaching an ideal closure rate up to 98.4% on day 14. The simple structure, multiple functions, and easy fabrication of the dressing may offer a promising strategy for treating chronic wounds, rooted in the challenges of bacterial infection, excessive exudate, and persistent inflammation.

Synthesis and evaluation of antibacterial and antioxidant effects of propolis nanoparticles and cinnamon nanostructures in preventive dentistry: Experimental and theoretical approaches.

Natural products such as green propolis and cinnamon have been used traditionally in medicine due to their medicinal value. Recently, interest has grown in developing nanotechnology-based approaches to enhance the biological activity of these compounds. This study evaluated the antioxidant and antibacterial properties of macro-sized and nanostructured forms of green propolis and cinnamon against Streptococcus mutans (S.mutans) and the 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay. The sonochemical method was used to synthesize green propolis nanoparticles (PNPs) and cinnamon nanoparticles (CNPs). Their size was confirmed by scanning electron microscopy (SEM) and dynamic light scattering measurements, while they were compared with propolis (P) and cinnamon (C). The antioxidant activity was measured using the DPPH assay, while the minimum inhibitory concentration (MIC) test determined the antibacterial activity against S.mutans. One-way analysis of variance (ANOVA) and Tukey's post hoc tests (α = 0.05) were conducted to analyze the data. Furthermore, docking calculations were carried out to examine the potential of incorporating any new supplements or therapies into your routine. The MIC were 5.46, 21.87, 21.87, and 175 g/L for PNPs, P, CNPs, and C groups, respectively. The PNPs exhibited the most significant antibacterial effect while C was weakest. About antioxidant activity, PNPs and P exhibited significant differences from other groups (P = 0.000 and 0.001, respectively), while CNPs and C showed no significant difference between each other (P = 0.07). The docking calculations revealed a strong interaction between both nanoparticles and S.mutans. The binding energy of dihydroflavonols on propolis nanoparticles was -6.83 kcal/mol, indicating a stable connection.

PBAT/lignin-ZnO composite film for food packaging: Photo-stability, better barrier and antibacterial properties

When PBAT used as film, stability deteriorates under sunlight exposure, and the poor barrier and antibacterial properties are also limiting its application. In this work, lignin-ZnO nanoparticles were prepared by hydrothermal method, as additives to fill the PBAT matrix, and PBAT-lignin-ZnO composite films were successfully prepared by melting and hot-pressing method. It is found that lignin could well dispersed the ZnO when its implantation into PBAT films, and lignin-ZnO not only maintaining tensile strength and thermal stability, and could prompt PBAT's crystallinity. Especially, P-L-ZnO-2 composite films have good photostability. After 60 h aging, it can still maintain good molecular weight, chemical structure and mechanical properties. Besides, these composite films have improved hydrophobicity, barrier and antibacterial properties, could prevent mildew and significantly reduce the weight loss rate, color difference and hardness changes of strawberries during storage. This work provides a potential film material for outdoor applications and food packaging.

Humidity-Responsive Amorphous Calcium-Magnesium Pyrophosphate/Cassava Starch Scaffold for Enhanced Neurovascular Bone Regeneration.

Developing a neurovascular bone repair scaffold with an appropriate mechanical strength remains a challenge. Calcium phosphate (CaP) is similar to human bone, but its scaffolds are inherently brittle and inactive, which require recombination with active ions and polymers for bioactivity and suitable strength. This work discussed the synthesis of amorphous magnesium-calcium pyrophosphate (AMCP) and the subsequent development of a humidity-responsive AMCP/cassava starch (CS) scaffold. The scaffold demonstrated enhanced mechanical properties by strengthening the intermolecular hydrogen bonds and ionic bonds between AMCP and CS during the gelatinization and freeze-thawing processes. The release of active ions was rapid initially and stabilized into a long-term stable release after 3 days, which is well-matched with new bone growth. The release of pyrophosphate ions endowed the scaffold with antibacterial properties. At the cellular level, the released active ions simultaneously promoted the proliferation and mineralization of osteoblasts, the proliferation and migration of endothelial cells, and the proliferation of Schwann cells. At the animal level, the scaffold was demonstrated to promote vascular growth and peripheral nerve regeneration in a rat skull defect experiment, ultimately resulting in the significant and rapid repair of bone defects. The construction of the AMCP/CS scaffold offers practical suggestions and references for neurovascular bone repair.

Efficient and sustainable design of pyridyl-bis-thiourea pincer ligand-immobilised Merrifield polymer precursor for arsenic ions adsorption

ABSTRACT An improved yield of a composite named Merrifield-pyridoyl-bis-thiourea derivative (MR-PyBTU) was effectively synthesised from the Merrifield Polymer Precursor (MR) and utilised for the adsorption of arsenic trioxide (As3+) ions from wastewater samples containing 1.5 mg/L of As3+ ions. The structure of the (PVAm-MMB) composite was confirmed using various analytical techniques, ensuring successful functionalization. Key experimental conditions namely pH, equilibrium time, starting concentration of As3+ ions, composite dosage, temperature, and choice of eluting agents were systematically optimised. At an ambient temperature, a pH value of 4.5, with 20 minutes of agitation, and an initial concentration of 250 mg/L As3+ ions, the composite demonstrated its highest sorption efficiency at a capacity of 50 mg/g. Equilibrium isotherm analyses indicated that the experimental data aligned more closely with the Langmuir model compared to the Freundlich model. Remarkably, the Langmuir model’s predicted uptake capability of 51.282 mg/g closely matched the actual observed values. Kinetic analyses supported by the pseudo-first-order model accurately described the sorption process, yielding a theoretical sorption capability of 49.113 mg/g. Thermodynamic assessments suggested that the sorption process is exothermic, spontaneous, and more favourable at lower temperatures. Efficient desorption of As3+ ions from the saturated composite was attained with 0.025 M NaOH, reaching approximately 98% efficiency. This composite’s ability to remove As3+ ions from wastewater aligns with Food and Agriculture Organization (WHO) and World Health Organization (FAO) guidelines, ensuring its safe discharge into marine environments after a single treatment cycle. Additionally, the compound 4-amino-N2, N6-bis((3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-yl) carbamothioyl) pyridine-2,6-dicarboxamide (PyBTU) exhibited potent antioxidant and antibacterial properties against Gram-negative bacteria, Gram-positive bacteria, Escherichia coli, and Bacillus subtilis.

Melt-extruded biocompatible surgical sutures loaded with microspheres designed for wound healing

Sutures are commonly used in surgical procedures and have immense potential for direct drug delivery into the wound site. However, incorporating active pharmaceutical ingredients into the sutures has always been challenging as their mechanical strength deteriorates. This study proposes a new method to produce microspheres-embedded surgical sutures that offer adequate mechanical properties for effective wound healing applications. The study used curcumin, a bioactive compound found in turmeric, as a model drug due to its anti-inflammatory, antioxidant, and anti-bacterial properties, which make it an ideal candidate for a surgical suture drug delivery system. Curcumin-loaded microspheres were produced using the emulsion solvent evaporation method with polyvinyl alcohol (PVA) as the aqueous phase. The microspheres’ particle sizes, drug loading (DL) capacity, and encapsulation efficiency (EE) were investigated. Microspheres were melt-extruded with polycaprolactone and polyethylene glycol via a 3D bioplotter, followed by a drawing process to optimise the mechanical strength. The sutures’ thermal, physiochemical, and mechanical properties were investigated, and the drug delivery and biocompatibility were evaluated. The results showed that increasing the aqueous phase concentration resulted in smaller particle sizes and improved DL capacity and EE. However, if PVA was used at 3% w/v or below, it prevented aggregate formation after lyophilisation, and the average particle size was found to be 34.32 ± 12.82 μm. The sutures produced with the addition of microspheres had a diameter of 0.38 ± 0.02 mm, a smooth surface, minimal tissue drag, and proper tensile strength. Furthermore, due to the encapsulated drug-polymer structure, the sutures exhibited a prolonged and sustained drug release of up to 14 d. Microsphere-loaded sutures demonstrated non-toxicity and accelerated wound healing in the in vitro studies. We anticipate that the microsphere-loaded sutures will serve as an excellent biomedical device for facilitating wound healing.

Green Synthesis and Characterization of Silver Nanoparticles from Nigella sativa L Seeds and It’s against Human Pathogenic Bacteria and Fungi

The green synthesis of silver nanoparticles (SNPs) is the most economical, rapid, facile, and eco-friendly technique. In this study, pathogenic bacteria from human stool were identified, and the antibacterial potency of Nigella sativa L. seed extracts containing SNPs was assessed. The identification of the isolated pathogenic bacteria was achieved through the analysis of their 16S rDNA sequences. The characterization of SNPs was done by ultraviolet–visible spectroscopy (UV-VIS spectroscopy), scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Six pathogenic bacteria were isolated from human stool and isolated bacteria were identified by 16S rDNA sequencing analysis. SNPs were found in the size range of 30-60nm and showed good antibacterial and antifungal activity. The maximum zone of inhibition was found against A. spanius at 32.0±0.8nm. Achromobacter spanius, Pseudomonas geniculate, and Enterobacter asburiae WL115 were extremely sensitive to heated treated nanoparticles at 100μgml-1. In the current work, N. sativa L. was investigated because it produced SNPs effectively, may be used as a safe, affordable agent, and may have antibacterial and antifungal properties. The potential biological uses of SNPs will be encouraged by these discoveries, which will drive future research.

Quaternized oxidized sodium alginate injectable hydrogel with high antimicrobial and hemostatic efficacy promotes diabetic wound healing

In this paper, a hydrogel material with efficient antibacterial, hemostatic, self-healing, and injectable properties was designed for the treatment of diabetic wounds. Firstly, quaternary ammonium salts were grafted with oxidized sodium alginate, and quaternized oxidized sodium alginate (QOSA) was synthesized. Due to the introduction of quaternary ammonium group it has antibacterial and hemostatic effects, at the same time, due to the presence of aldehyde group it can be reacted with carboxymethyl chitosan (CMCS) to form a hydrogel through the Schiff base reaction. Furthermore, deer antler blood polypeptide (DABP) was loaded into the hydrogel (QOSA&CMCS&DABP), showing good swelling ratio and bacteriostatic effect. In vitro and in vivo experiments demonstrated that the hydrogel not only quickly inhibited hepatic hemorrhage in mice and reduced coagulation index and clotting time in vitro, but also significantly enhanced collagen deposition at the wound site, accelerating wound healing. This demonstrates that the multifunctional hydrogel materials (QOSA&CMCS&DABP) have promising applications in the acceleration of skin wound healing and antibacterial promotion.

Chitosan/MgO NPs/CQDs bionanocomposite coating: Fabrication, characterization and determination of antimicrobial efficacy

The development of new polymer nanocomposites or antibacterial coatings is crucial in combating drug-resistant infections, particularly bacterial infections. In this study, a new chitosan polymer based nanocomposite reinforced with magnesium oxide nanopowders and carbon quantum dots was fabricated by sol-gel technique and coated on 316 L stainless steel. In order to gaining the optimal amount of components to achieve the maximum antibacterial properties, the effect of concentration of nanocomposite components on its antibacterial properties was investigated. Crystal structure, microstructure, elemental dispersion, size distribution, chemical composition and morphology of nanocomposite and coating were characterized with various analyses. The obtained results exhibited that the carbon quantum dot and magnesium oxide nanopowders were distributed uniformly and without agglomeration in the chitosan matrix and created a uniform coating. The antibacterial properties of the synthesized samples against Staphylococcus aureus bacteria (gram positive) were evaluated using disk diffusion and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) antibacterial tests. The inhibition growth zone formed around the antibiotic and nanocomposite 25 mg/ml under dark and light was about 32 and 14, 11 mm, respectively. Also, MIC and MBC values for final nanocomposite were 62.5 and 125 μg/ml, respectively.

Antibacterial and antibiofilm properties of cinnamon essential oil on Pseudomonas tolaasii and application of potato starch/CEO active pads in preservation of mushroom (Agaricus bisporus)

Pseudomonas tolaasii (P. tolaasii) is considered to be the main pathogen of brown spot disease in mushrooms. Cinnamon essential oil (CEO), a natural bacteriostatic agent, has potential application prospects in the field of food preservation. The purpose of this study was to explore the antibacterial mechanism of CEO on P. tolaasii, and to prepare an active pad to study the preservation effect of mushroom, so as to provide a basis for the development of natural antibacterial agents. P. tolaasii was isolated from browning mushroom and identified by 16S rRNA gene sequencing. The antibacterial and antibiofilm activities of cinnamon essential oil (CEO) on P. tolaasii and its application in mushrooms were investigated. The results indicated that CEO had a significant inhibitory effect on P. tolaasii. After the CEO treatment, the surface of P. tolaasii cells was damaged, and significant leakage of entocyte was observed. In addition, CEO could effectively induce oxidative stress and lipid peroxidation in P. tolaasii cells, and cause irreversible damage to cell membranes, leading to energy and respiratory metabolism disorders. The activity of ROS defense enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were significantly inhibited (P < 0.05), aggravating the oxidative damage to P. tolaasii. The crystal violet staining assay and scanning electron microscopy revealed that CEO treatment not only inhibited biofilm formation, but also effectively eradicated mature biofilm. The application effects displayed that the active pads packing containing CEO had excellent antibacterial effect and maintain the quality of mushroom (Agaricus bisporus). The results of this study will provide references for further research and application of natural food antibacterial agents.

Biogenic amine tryptamine in human vaginal probiotic isolates mediates matrix inhibition and thwarts uropathogenic E. coli biofilm

Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC’s swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC–MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.

Coptis rhizome extract influence on Streptococcus pneumoniae through autolysin activation

This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts’ biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance.

Investigation of the acute impact of rosemary consumption on brain activity in healthy volunteers

ABSTRACT Objectives Rosmarinus officinalis L. (rosemary) is a fragrant plant of the mint family, broadly known as a nourishment flavoring agent; it is additionally utilized in conventional people cures for its anti-inflammatory, diuretic, and antibacterial properties. Intense cognitive impacts from devouring plant-based flavonoids can be measured with electroencephalography (EEG), which records unconstrained brain movement. Brain activity can be evaluated amid independent states or whereas performing attentional assignments. This study aimed to determine the impact of rosemary consumption on cognitive consequences. Methods Twenty volunteers took part in the study. EEG was taken for each volunteer twice, before drinking rosemary extract and around one hour after drinking it. EEG information was recorded with a Micromed recording framework inspecting rate of 512 Hz. EEG signals were prepared to be utilized in EEGLAB, an open-source toolbox within the MATLAB environment. The information obtained after the EEG recording was compared with the preliminary EEG information. Results The signal’s power spectral density in theta, delta, and beta frequency bands modestly increased in males and females. Even though there was a significant increase in power at the alpha frequency band in both sexes, this increment was not specific channel-wise. Discussion The obtained data are consistent with the expected results and similar studies conducted, suggesting that the consumption of rosemary is beneficial for cognitive function in the short term. It is anticipated that forthcoming long-term studies will support the existing data.

Construction of fully bio‐based flame retardant and antibacterial coating on polyester fabric with chitosan and ammonium phytate

AbstractIn this work, a flame retardant and antibacterial coating was constructed on the surface of polyester (PET) fabric by a simple layer‐by‐layer self‐assembly method based on chitosan (CS) and ammonium phytate (APA). The introduction of the coating significantly improved the flame retardant, anti‐dripping, and antibacterial properties of PET fabrics. The PET fabric that has been treated exhibits a limiting oxygen index of 34.6%. During the vertical flame test, it forms an expanded char layer, reduces the damage length to 3.4 cm, and produces no molten drops. The cone calorimeter test results revealed that the peak heat release rate of the treated PET fabric decreased by 62.0%. Additionally, the finished PET fabric has significant antibacterial properties against Escherichia coli, a slight increase in tensile breaking strength, and a slight decrease in whiteness index. This study presents a fully bio‐based, simple, and effective method for flame retardant, anti‐dripping, and antibacterial finishing of PET fabrics.

Chitosan-Based Films with Essential Oil Components for Food Packaging

Chitosan-based films show great potential in terms of application in food preservation and are also promising carriers of biologically active ingredients. This paper presents the potential use of chitosan-based films with the addition of essential oil components, e.g., carvacrol, eugenol, and isoeugenol, intended for food packaging. The characteristics of the obtained films were determined, including antibacterial, mechanical, barrier, and structural parameters. In addition, the antibacterial and antioxidant effects of the essential oil components were assessed. Eugenol (44.41%) and isoeugenol (43.56%) showed high antiradical activities, similar to the activity of Trolox (44.33%), which is used as a standard antioxidant. In turn, carvacrol was characterized by the strongest effect against the examined strains of bacteria, both Gram-positive and Gram-negative. The chitosan film with carvacrol showed the most valuable antibacterial and mechanical properties (tensile strength and elongation at break). The antibacterial activities of the chitosan–carvacrol films were higher than that of the carvacrol solution. The inhibition zones of the chitosan–carvacrol films were in the range 29–41 mm (except for Enterococcus faecalis, with an inhibition zone of 15 mm) compared to the inhibition zones of the carvacrol solution (28 mm). The results showed that chitosan is an effective carrier of fragrance compounds, mainly carvacrol. However, all the tested chitosan-based films with the addition of fragrance compounds showed appropriate parameters (biological, mechanical, and barrier), which makes them an ecological alternative to plastics intended for food packaging.