Broad-spectrum Antimicrobial Activity Research Articles

Endodontic irrigants from a comprehensive perspective.

This review article explores the fundamental principles of modern endodontics with a focus on root canal cleaning and shaping. It reviews commonly used endodontic irrigant, namely sodium hypochlorite (NaOCl), herbal extracts, chlorhexidine (CHX), and chelating agents, highlighting their properties, applications, and potential drawbacks. NaOCl, a key antimicrobial agent, demonstrates effectiveness against various microorganisms but poses challenges such as high cytotoxicity. Herbal extracts, gaining recognition in endodontics, present an alternative with potential advantages in preserving dentin integrity. CHX, known for its broad-spectrum antimicrobial activity, is discussed in both liquid and gel formulations, emphasizing its role in reducing smear layer formation and preserving hybrid layer durability. Chelating agents, specifically ethylenediaminetetraacetic acid and citric acid, play a vital role in removing the smear layer, enhancing dentin permeability, and facilitating the penetration of antimicrobial agents. The review article underscores the importance of careful application and consideration of each irrigant's properties to ensure safe and effective endodontic procedures. It serves as a valuable guide for clinicians in selecting appropriate irrigants based on specific treatment requirements.

Assessment of Multifunctional Activity of a Postbiotic Preparation Derived from Lacticaseibacillus paracasei Postbiotic-P6

Postbiotics possess various functional activities, closely linked to their source bacterial strains and preparation methods. Therefore, the functional activities of postbiotics need to be evaluated through in vitro and in vivo methods. This study aims to prepare a postbiotic and explore its antihemolytic, anti-inflammatory, antioxidant, and antibacterial activities. Specifically, a postbiotic preparation named PostbioP-6 was prepared by intercepting 1–5 kDa of Lacticaseibacillus paracasei Postbiotic-P6 fermentation broth. The results demonstrate that PostbioP-6 exhibited notable biological activities across multiple assays. It showed significant antihemolytic activity, with a 4.9–48.1% inhibition rate at 10–50% concentrations. Anti-inflammatory effects were observed both in vitro, where 8–40% PostbioP-6 was comparable to 259.1–645.4 μg/mL diclofenac sodium, and in vivo, where 3.5 and 4.0 μL/mL PostbioP-6 significantly reduced neutrophil counts in inflamed zebrafish (p < 0.05). Antioxidant properties were evident through increased reducing power (OD700 increased from 0.279 to 2.322 at 1.25–12.5% concentrations), DPPH radical scavenging activity (38.9–92.4% scavenging rate at 2.5–50% concentrations), and hydroxyl radical scavenging activity (4.66–10.38% scavenging rate at 0.5–4% concentrations). Additionally, PostbioP-6 demonstrated antimicrobial activity against two Gram-positive bacteria, eight Gram-negative bacteria, and one fungus. Furthermore, PostbioP-6 significantly inhibited the increase in peroxide value and malondialdehyde content in cookies, highlighting its potential application in food preservation. In conclusion, we prepared a novel postbiotic, termed PostbioP-6, which proved to have prominent anti-hemolytic, anti-inflammatory, antioxidant, and broad-spectrum antimicrobial activities. The multifunctional properties of PostbioP-6 position it as a potentially effective functional food supplement or preservative. In the future, further research is necessary to elucidate the precise mechanisms of action, identify the active components, and validate its biological activities in animal models or clinical trials.

Evaluation of Anti‐Chlamydial Effect of a Synthetic Linear Peptide

AbstractInspired by the broad spectrum of antimicrobial activity exhibited by Magainins and SMAP‐28, and based on their chemical structures, several linear peptides were designed and synthesized with the aim of achieving peptides possessing promising anti‐chlamydial activity with lower cytotoxicity towards human normal cell lines. We found these peptides to be cytotoxic against human normal cell lines, except for one designated as DJ‐7, which was utilized in subsequent experiments, while the others were excluded. Peptide DJ‐7 was readily synthesized using standard Fmoc‐SPPS, and its anti‐chlamydial activity was investigated against HeLa cells (ATCC CCL‐2) infected with Chlamydia trachomatis L2 (ATCC VR‐902B) at MOI 1 for 2 hours, followed by treatment with increasing concentrations of peptide DJ‐7 (15–60 μg/mL). Microscopic examination revealed a significant reduction in the total number of bacterial inclusions in cells by around 50 % and 80 % after treatment with 15 μg/mL (5.5 μM) and 30 μg/mL (11 μM) of peptide DJ‐7, respectively, compared to control untreated infected cells. The impact of peptide DJ‐7 treatment on the development of infectious C. trachomatis serovar L2 progeny was investigated, demonstrating a significant decrease in infectious chlamydia after treatment with peptide DJ‐7. This suggests that chlamydia failed to complete its typical developmental cycle, indicating that peptide DJ‐7 exhibits anti‐chlamydial properties, by disrupting the normal bacterial development process. Our results indicate that peptide DJ‐7 is a promising lead peptide for further development as a potential anti‐chlamydial agent.

Glycine-replaced epinecidin-1 variant bestows better stability and stronger antimicrobial activity against a range of nosocomial pathogenic bacteria.

Epinecidin-1 (epi-1), an antimicrobial peptide first identified in marine grouper fish, has multifunctional bioactivities. The present study aims to improve its therapeutic potential via structural modifications that could enhance its antimicrobial activity and stability. To achieve it, we replaced glycine and the first histidine in the parent epi-1 with lysine, which resulted in a peptide with a repeating KXXK motif and improved physiochemical properties related to antimicrobial activity. This modified peptide, referred to as glycine-to-lysine replaced-epi-1, also gained stability and a twofold increase in helical propensity. To produce the active peptide, overlap extension PCR was employed to generate the gene of GK-epi-1 via site-directed mutagenesis, which was then cloned into the pET-32a vector and expressed as a recombinant fusion protein in Escherichia coli C43 (DE3) strain. The recombinant protein was purified and digested with enterokinase to release the active peptide fragment, which was then evaluated for antimicrobial activity and stability. The lysine substitution led to an enhancement in broad-spectrum antimicrobial activity against a wide range of nosocomial pathogenic bacteria.

Ellagic acid-modified gold nanoparticles to combat multi-drug resistant bacterial infections in vitro and in vivo.

The overuse of antibiotics has led to the rapid development of multi-drug resistant bacteria, making antibiotics increasingly ineffective against bacterial infections. Consequently, there is an urgent need to develop alternative strategies to combat multi-drug-resistant bacterial infections. In this study, gold nanoparticles modified with ellagic acid (EA-AuNPs) were prepared using a simple and mild one-pot hydrothermal process. EA-AuNPs demonstrated high bactericidal efficacy and broad-spectrum antimicrobial activities against clinical isolates of the antibiotic-resistant ESKAPE pathogens. Furthermore, EA-AuNPs effectively disperse biofilms of multi-drug-resistant bacteria. Additionally, EA-AuNPs mitigated inflammatory responses at the bacterial infection sites. The combined bactericidal and anti-inflammatory treatment with EA-AuNPs resulted in faster curing of peritonitis caused by Staphylococcus aureus in mice compared to treatment with free EA or gentamicin. Moreover, transcriptome analysis revealed that EA-AuNPs exhibited a multi-targeting mechanism, making resistance development in pathogens more challenging than traditional antibiotics that recognize specific cellular targets. Overall, EA-AuNPs emerged as a promising antimicrobial agent against multi-drug-resistant bacterial infections.

Insights into the Cytotoxicity and Irritant Potential of Chlorhexidine Digluconate: An In Vitro and In Ovo Safety Screening.

Chlorhexidine (CHX) represents one of the most commonly used antiseptics in dentistry and other medical-pharmaceutical fields due to its broad-spectrum antimicrobial activity. However, the potential toxic events arising from its common use in practice has become a subject of increasing concern. Thus, the present study was designed to investigate the potential toxicity of CHX digluconate at concentrations covering its antibacterial properties (0.0002-0.2%) in HGF primary gingival fibroblasts, HaCaT immortalized human keratinocytes, and JB6 Cl 41-5a epidermal cells, as well as its irritant action in ovo. Our results indicate that CHX exerted a concentration- and time-dependent cytotoxicity in all cell lines, which was evidenced by the reduction in cell viability, number, and confluence, damaged cell membrane integrity, impaired cell morphology, and specific apoptotic nuclear shape. The highest cytotoxicity was caused by CHX digluconate 0.02% and 0.2%, concentrations, at which an irritant effect on the chorioallantoic membrane was also observed. The novel findings revealed in this research contribute to the overall safety profile of CHX and stand as a basis for further investigations in this regard.

Litsea cubeba essential oil: Extraction, chemical composition, antioxidant and antimicrobial properties, and applications in the food industry.

Litsea cubeba (Lour.) Pers. (Lauraceae) is a valuable industrial crop that produces essential oil. The essential oil extracted from L. cubeba (LCEO) has broad-spectrum antimicrobial activity and high antioxidant properties, with great potential for increased usage in the food industry. This literature review summarizes the extraction techniques, content and chemical composition, and antioxidant and antimicrobial activities of LCEO, with a focus on its usage in the food industry, which is an area of substantial recent research. The chemical composition of LCEO, which is affected by various factors, plays a key role in determining its bioactivity and usage in food. The potent antimicrobial activity of LCEO against various foodborne pathogens gives it potential for use in food packaging and preservation to extend shelf life. Future research challenges include the elucidation of the role and mechanism of individual chemical components of LCEO in inhibiting specific foodborne microorganisms; cultivar development to produce germplasm that yields essential oils of the desired chemical composition; and the development of commercial products that can be used in the food industry.

A novel antibiotic: the antimicrobial effects of CFBSA and its application on electronspun wound dressing

N-chloro-N-fluorobenzenesulfonylamide (CFBSA), was a novel chlorinating reagent, which exhibits potential antibacterial activities. In this study, CFBSA was confirmed as a wide-broad antimicrobial and bactericidal drug against different gram-negative bacteria, gram-positive bacteria and fungi, while it was found to have low cytotoxicity for eukaryotic cells. In addition, microorganism morphology assay and oxidative stress test was used to determine the antimicrobial mechanisms of CFBSA. According to the results, CFBSA probably had a target on cell membrane and killed microorganism by disrupting its cell membrane. Then, CFBSA was first combined with poly(L-lactide-co-caprolactone) (PLCL)/SF via electrospinning and applied in wound dressings. The characterization of different PLCL/SF of CFBSA-loaded nanofibrous mats was investigated by SEM, water contact angle, Fourier transform infrared spectroscopy, cell compatibility and antimicrobial test. CFBSA-loaded PLCL/SF nanofibrous mats showed excellent antimicrobial activities. In order to balance of the biocompatibility and antibacterial efficiency, SP-2.5 was selected as the ideal loading concentration for further application of CFBSA-loaded PLCL/SF. In conclusion, the electrospun CFBSA-loaded PLCL/SF nanofibrous mat with its broad-spectrum antimicrobial and bactericidal activity and good biocompatibility showed enormous potential for wound dressing.

Treating Infected Non-Healing Venous Leg Ulcers with Medical-Grade Honey: A Prospective Case Series.

Venous leg ulcers (VLUs) are hard-to-heal wounds and are prone to microbial colonization. Innovative and improved therapies are thus required to resolve local infection and enhance the wound healing process. The objective of this study was to evaluate the effectiveness of medical-grade honey (MGH) for the treatment of clinically infected and non-healing VLUs. This prospective case series included nine patients with an average age of 83.4 years (range: 75-91 years) with a total of eleven VLUs, previously ineffectively treated with various products. Major risk factors for the appearance of VLUs were chronic venous insufficiency, advanced age, multiple comorbidities (particularly cardiovascular diseases), and impaired mobility. All wounds presented with local signs of infection. Upon presentation, treatment was commenced with a range of MGH-based products (L-Mesitran®). Clinical signs of infection were eliminated by MGH after 2.2 weeks on average (range: 1-4 weeks), and wounds were completely healed after 7 weeks on average (range: 3-18 weeks). No further complications or recurrences were observed. MGH has a broad-spectrum antimicrobial activity and promotes rapid healing, thus improving patients' quality of life. Moreover, MGH-based products are safe, easy to use, cost-effective, and can effectively treat VLUs alone or in combination with standard-of-care therapies.

Synthesis and broad-spectrum biocidal effect of novel gemini quaternary ammonium compounds

Since the discovery of antimicrobial agents, the misuse of antibiotics has led to the emergence of bacterial strains resistant to both antibiotics and common disinfectants like quaternary ammonium compounds (QACs). A new class, ’gemini’ QACs, which contain two polar heads, has shown promise. Octenidine (OCT), a representative of this group, is effective against resistant microorganisms but has limitations such as low solubility and high cytotoxicity. In this study, we developed 16 novel OCT derivatives. These compounds were subjected to in silico screening to predict their membrane permeability. Testing against nosocomial bacterial strains (G+ and G-) and their biofilms revealed that most compounds were highly effective against G+ bacteria, while compounds 7, 8, and 10–12 were effective against G- bacteria. Notably, compounds 6–8 were significantly more effective than OCT and BAC standards across the bacterial panel. Compound 12 stood out due to its low cytotoxicity and broad-spectrum antimicrobial activity, comparable to OCT. It also demonstrated impressive antifungal activity. Compound 1 was highly selective for fungi and four times more effective than OCT without its cytotoxicity. Several compounds, including 4, 6, 8, 9, 10, and 12, showed strong virucidal activity against murine cytomegalovirus and herpes simplex virus 1. In conclusion, these gemini QACs, especially compound 12, offer a promising alternative to current disinfectants, addressing emerging resistances with their enhanced antimicrobial, antifungal, and virucidal properties.

Fatty acid-derived ionic liquids as soft and sustainable antimicrobial agents

In this study, two sustainability goals are addressed: 1) developing new soft antimicrobial agents (to control antimicrobial resistance) and 2) using natural bio-derived components for this purpose. Fatty acids of bio-renewable origin (stearin, palm kernel and coconut oils) were found to be excellent starting materials for obtaining ester-functionalized ionic liquids (ILs) and mixtures. A series of soft antimicrobial agents based on imidazolium, pyridinium and cholinium ILs with long alkyl ester chains were synthesized, and their properties were examined. The length of the alkyl chain had a notable effect on the physicochemical and biological properties of the synthesized materials. The introduction of a butyl linker and an ester bond lowered the melting point, increased the antimicrobial effectiveness and reduced the cytotoxicity compared to those of non-functionalized ILs with the same hydrocarbon chain. ILs and mixtures with medium chain lengths (C12, C13 and C15) were recognized as promising substitutes for demanding cationic antimicrobial agents. The presence of an ester bond connecting the polar head and hydrophobic tail can promote the breakdown of amphiphilic molecules into less toxic initial compounds. These findings make an important contribution to the development of new, effective amphiphiles with broad-spectrum antimicrobial activity and lower environmental impact.

Green synthesis and characterization of AgNPs/CDs hybrid system for enhanced oxidation resistance at physiological concentration of H2O2

Silver nanoparticles (AgNPs) have emerged as promising antimicrobial agents due to their unique properties and broad-spectrum antimicrobial action. However, their interaction with hydrogen peroxide (H2O2) in the bloodstream can lead to their oxidation, thereby reducing their antimicrobial effectiveness and potentially posing threats to human health. This study presents a novel approach to enhance the oxidation resistance of AgNPs by integrating them with carbon dots (CDs) to form an AgNPs/CDs hybrid system. CDs, with their exceptional biocompatibility and functionalized surface, can interact with AgNPs to provide a protective layer. Our green synthesis method employed microwave-assisted techniques using only three reagents: silver nitrate, l-tryptophan, and glucose. The characterization of the hybrid system was conducted using Ultraviolet–Visible spectroscopy (UV/Vis), Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM), and Finite Element Analysis (FEA). UV/Vis spectroscopy revealed a red shift in the absorption peak of the hybrid system compared to pure AgNPs, confirming the interaction between CDs and AgNPs. TEM and HRTEM analyses, supported by the PASAD plug-in and Image Pro‐Plus software, respectively, elucidated the structural arrangement and interaction of these nanoparticles. Additionally, FEA computations using FreeFEM software platform forecasted the resonant wavelengths.

Isolation, characterization and antimicrobial properties of hepatopancreas lectin of the freshwater crab Oziotelphusanaga

Lectins are versatile proteins that specifically recognize and interact with sugar moieties expressed on the cell surface. The potential of lectin in drug targeting and delivery has instigated interest to identify natural lectins. Crabs have been identified as a rich source of lectin because the innate immune system is activated on encounter of pathogens and helps in the production of lectin. Although the presence of lectins in crab's hemolymph is well documented, little information about lectin in hepatopancreas, a vital organ for immunity and digestion in crustaceans, is currently available. A calcium dependent lectin (75 kDa) was purified from the hepatopancreas of the freshwater crab Oziotelphusa naga by bioadsorption and fetuin linked Sepharose 4B affinity chromatography technique. The isolated hepatopancreas lectin is calcium dependent and maximum agglutination was observed with rabbit erythrocytes. The hemagglutinating activity of the hepatopancreas lectin was effectively inhibited by sugars, such as α-lactose, GlcNAc, trehalose and NeuAc. Compared to sialylated N-glycosylated proteins including transferrin and apo transferrin, sialylated O-glycosylated proteins like fetuin exhibited stronger inhibitory effect. The ability of erythrocytes to bind hepatopancreas lectin has been diminished by desialylation of the potent inhibitor, indicating the significance of sialic acid in lectin-ligand interactions. The purified hepatopancreas lectin showed a broad spectrum of antimicrobial activity against bacteria Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, E. coli and fungi Candida albicans and Aspergillus niger. The findings of this study demonstrate the significance of hepatopancreas lectin as a multifunctional defense protein that inhibits the growth of bacteria and fungi.

Three-Dimensional Melted Electrowriting Drug Coating Fibers for the Prevention of Device-Associated Infections: A Pilot Study.

Medical device-related infections (DRIs), especially prevalent among critically ill patients, impose significant health and economic burdens and are mainly caused by bacteria. Severe infections often necessitate device removal when antibiotic therapy is inefficient, delaying recovery. To tackle this issue, PCL drug-eluting coated meshes were explored, and they were printed via melt electrowriting (MEW). These meshes were coated with gentamicin sulfate (GS) and tetracycline hydrochloride (TCH) and underwent FTIR analysis to confirm drug integration. Antimicrobial activity was assessed via agar diffusion assays and biofilm formation assays against bacterial strains: Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 43300, and Staphylococcus epidermidis ATCC 35984. FTIR analysis evidenced the presence of the drugs in the meshes. TCH displayed broad-spectrum antimicrobial activity against all strains, whereas GS was effective against all except S. aureus. These findings indicate the potential of cost-effective ultra-fine drug coating fibers for medical device applications, offering infection prevention during implantation. This preliminary study demonstrates the feasibility of producing drug-eluting fibers for DRI prevention through a non-toxic, fast, and cost-efficient technique, paving the way for enhanced patient care and reduced healthcare costs.

Pharmacokinetics and pharmacodynamics of intravenous delafloxacin in healthy subjects: model-based dose optimization.

Delafloxacin, a fluoroquinolone antibiotic to treat skin infections, exhibits a broad-spectrum antimicrobial activity. The first randomized, open-label phase I clinical trial was conducted to assess the safety and pharmacokinetics (PK) of intravenous delafloxacin in the Chinese population. A population pharmacokinetic (PopPK) model based on the clinical trial was conducted by NONMEM software. Monte Carlo simulation was performed to evaluate the antibacterial effects of delafloxacin at different doses in different Chinese populations. The PK characteristics of delafloxacin were best described by a three-compartment model with mixed linear and nonlinear clearance. Body weight was included as a covariate in the model. We simulated the AUC0-24h in a steady state at five doses in patient groups of various weights. The results indicated that for patients weighing 70 kg and treated with methicillin-resistant Staphylococcus aureus (MRSA) infections, a minimum dose of 300 mg achieved a PTA > 90% at MIC90 of 0.25 µg/mL, suggesting an ideal bactericidal effect. For patients weighing less than 60 kg, a dose of 200 mg achieved a PTA > 90% at MIC90 of 0.25 µg/mL, also suggesting an ideal bactericidal effect. Additionally, this trial demonstrated the high safety of delafloxacin in single-dose and multiple-dose groups of Chinese. Delafloxacin (300 mg, q12h, iv) was recommended for achieving optimal efficacy in Chinese bacterial skin infections patients. To ensure optimal efficacy, an individualized dose of 200 mg (q12h, iv) could be advised for patients weighing less than 60 kg, and 300 mg (q12h, iv) for those weighing more than 60 kg.

Formulation of Mouthwash Using Combined Herbal Extracts to Control the Predominant Oral Pathogens and Biofilm

IntroductionGlobally, oral disease is a major health problem, which affects the quality of life. The role of oral microflora in the oral diseases is well established. However, with the increase in the frequency of oral disease, the development of antimicrobial drug resistance to the existing drugs has insisted on searching for alternative drugs from plant sources. Herein, herbal-based mouthwash is formulated to effectively control the dominant oral pathogens. MethodsThe antimicrobial activity of plant extracts was evaluated against oral pathogens by zone of inhibition test. Mouthwash was formulated with one gram of each plant extracts (Rosa damascena flower petals, Coleus amboinicus leaves, Psidium guajava leaves, and Phyllanthus acidus fruits) in 10% ethanol. Antimicrobial efficacy of the formulated mouthwash was assessed against Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, and Candida albicans by standard protocol. Also, the antibiofilm effect of the formulated mouthwash was assessed against preformed S mutans biofilm and visualised using SEM and CLSM. ResultsThe formulated mouthwash exhibits excellent broad-spectrum antimicrobial activity. The minimum inhibitory concentration result indicates that the susceptibility of the pathogens was found as follows: S aureus <S mutans <C albicans <E faecalis <E coli. Also, it shows a great anti-inflammatory effect. SEM and CLSM images reveal that the formulated mouthwash has the potential to inhibit the oral biofilm of S. mutants. ConclusionsThis study concludes that the formulated herbal-based mouthwash might be useful in controlling multiple oral pathogens and biofilms.

Deep-learning-enabled antibiotic discovery through molecular de-extinction.

Molecular de-extinction aims at resurrecting molecules to solve antibiotic resistance and other present-day biological and biomedical problems. Here we show that deep learning can be used to mine the proteomes of all available extinct organisms for the discovery of antibiotic peptides. We trained ensembles of deep-learning models consisting of a peptide-sequence encoder coupled with neural networks for the prediction of antimicrobial activity and used it to mine 10,311,899 peptides. The models predicted 37,176 sequences with broad-spectrum antimicrobial activity, 11,035 of which were not found in extant organisms. We synthesized 69 peptides and experimentally confirmed their activity against bacterial pathogens. Most peptides killed bacteria by depolarizing their cytoplasmic membrane, contrary to known antimicrobial peptides, which tend to target the outer membrane. Notably, lead compounds (including mammuthusin-2 from the woolly mammoth, elephasin-2 from the straight-tusked elephant, hydrodamin-1 from the ancient sea cow, mylodonin-2 from the giant sloth and megalocerin-1 from the extinct giant elk) showed anti-infective activity in mice with skin abscess or thigh infections. Molecular de-extinction aided by deep learning may accelerate the discovery of therapeutic molecules.

Photosensitizer-Amplified Antimicrobial Materials for Broad-Spectrum Ablation of Resistant Pathogens in Ocular Infections.

The emergence of multidrug resistant (MDR) pathogens and the scarcity of new potent antibiotics and antifungals are one of the biggest threats to human health. Antimicrobial photodynamic therapy (aPDT) combines light and photosensitizers to kill drug-resistant pathogens; however, there are limited materials that can effectively ablate different classes of infective pathogens. In the present work, a new class of benzodiazole-paired materials is designed as highly potent PDT agents with broad-spectrum antimicrobial activity upon illumination with nontoxic light. The results mechanistically demonstrate that the energy transfer and electron transfer between nonphotosensitive and photosensitive benzodiazole moieties embedded within pathogen-binding peptide sequences result in increased singlet oxygen generation and enhanced phototoxicity. Chemical optimization renders PEP3 as a novel PDT agent with remarkable activity against MDR bacteria and fungi as well as pathogens at different stages of development (e.g., biofilms, spores, and fungal hyphae), which also prove effective in an ex vivo porcine model of microbial keratitis. The chemical modularity of this strategy and its general compatibility with peptide-based targeting agents will accelerate the design of highly photosensitive materials for antimicrobial PDT.

Indigenous Ethiopian traditional medicinal plant leaf extract, Croton macrostachyus, loaded PCL electrospun nanofibrous mat as potential wound dressing: In vitro analysis

The main aim of this study was to investigate the potential application of an indiginous Ethiopian medicinal plant, Croton macrostachyus, into PCL nanofibers through electrospinning for the first time. Croton macrostachyus (CM) leaf has antibacterial and wound healing properties. Croton macrostachyus of 1%, 3%, 5%, and 7% (w/v) incorporated PCL nanofibrous mats were produced through electrospinning. The produced nanofibrous mats morphology observed by scanning electron microscopy (SEM) was found to be continuous, bead-free, and interconnected. The average diameters of PCL, PCL-1%CM, PCL-3%CM, PCL-5%CM, and PCL-7%CM nanofibrous mat is 309 ± 114, 271 ± 66, 235 ± 56, 226 ± 65, and 216 ± 42 nm, respectively. According to the FTIR results, the CM leaf extract was successfully incorporated into the PCL nanofibers. The bacterial reduction percentage value of PCL-1%CM, PCL-3%CM, PCL-5%CM, and PCL-7%CM nanofiber mats against S. aureus is 77.00%, 99.88%, 99.91%, and 99.99%, and 35.00%, 78.00%, 90.00%, and 99.30% against E. coli. The in vitro release study showed that there was an immediate release of CM within 24 h and then a steady sustained release of 51.36, 53.92, 54.99, and 57.12% up to 72 h at 1%, 3%, 5%, and 7% concentration, respectively. The presence of CM leaf extract in the PCL nanofiber increased the hydrophilicity of the pure PCL nanofiber (100% hydrophilic at 7% leaf extract concentration). In general, the results of the in vitro study confirmed that the PCL nanofibrous mats loaded with CM leaf extract are suitable for use as an effective wound dressing with a broad spectrum of antimicrobial activity and hydrophilic properties.

Heterologous expression of frog antimicrobial peptide Odorranain-C1 in Pichia pastoris: Biological characteristics and its application in food preservation

To reduce food spoilage and deterioration caused by microbial contamination, antimicrobial peptides (AMPs) have gradually gained attention as a biological preservative. Odorranain-C1 is an α-helical cationic antimicrobial peptide extracted from the skin of frogs with broad-spectrum antimicrobial activity. In this study, we achieved the expression of Odorranain-C1 in Pichia pastoris (P. pastoris) (also known as Komagataella phaffii) by employing DNA recombination technology. The recombinant Odorranain-C1 showed broad-spectrum antibacterial activity and displayed a minimum inhibitory concentration within the range of 8–12 μg.mL-1. Meanwhile, Odorranain-C1 exhibited superior stability and lower hemolytic activity. Mechanistically, Odorranain-C1 disrupted the bacterial membrane's integrity, ultimately causing membrane rupture and subsequent cell death. In tilapia fillets preservation, Odorranain-C1 inhibited the total colony growth and pH variations, while also reducing the production of total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA). In conclusion, these studies demonstrated the efficient recombinant expression of Odorranain-C1 in P. pastoris, highlighting its promising utilization in food preservation.