Antimicrobial Activity Research Articles

The impact of trauma relevant concentrations of prostaglandin E2 on the anti-microbial activity of the innate immune system

BackgroundThe mechanisms underlying the state of systemic immune suppression that develops following major trauma are poorly understood. A post-injury increase in circulating levels of prostaglandin E2 (PGE2) has been proposed as a contributory factor, yet few studies have addressed how trauma influences PGE2 biology.MethodsBlood samples from 95 traumatically-injured patients (injury severity score ≥8) were collected across the pre-hospital (≤2 hours), acute (4-12 hours) and subacute (48-72 hours) post-injury settings. Alongside ex vivo assessments of lipopolysaccharide (LPS)-induced cytokine production by monocytes, neutrophil reactive oxygen species production and phagocytosis, serum concentrations of PGE2 and its scavenger albumin were measured, and the expression of enzymes and receptors involved in PGE2 synthesis and signalling analysed. Leukocytes from trauma patients were treated with cyclooxygenase (COX) inhibitors (indomethacin or NS-398), or the protein kinase A inhibitor H89, to determine whether injury-induced immune suppression could be reversed by targeting the PGE2 pathway. The effect that trauma relevant concentrations of PGE2 had on the anti-microbial functions of neutrophils, monocytes and monocyte-derived macrophages (MDMs) from healthy controls (HC) was examined, as was the effect of PGE2 on efferocytosis. To identify factors that may trigger PGE2 production post-trauma, leukocytes from HC were treated with mitochondrial-derived damage associated molecular patterns (mtDAMPs) and COX-2 expression and PGE2 generation measured.ResultsPGE2 concentrations peaked in blood samples acquired ≤2 hours post-injury and coincided with significantly reduced levels of albumin and impaired LPS-induced cytokine production by monocytes. Significantly higher COX-2 and phospholipase A2 expression was detected in neutrophils and/or peripheral blood mononuclear cells isolated from trauma patients. Treatment of patient leukocytes with indomethacin, NS-398 or H89 enhanced LPS-induced cytokine production and neutrophil extracellular trap generation. Exposure to physiological concentrations of PGE2 suppressed the anti-microbial activity of monocytes, neutrophils and MDMs of HC, but did not influence efferocytosis. In a formyl-peptide receptor-1 dependent manner, mtDAMP treatment significantly increased COX-2 protein expression in neutrophils and monocytes, which resulted in increased PGE2 production.ConclusionsPhysiological concentrations of PGE2 suppress the anti-microbial activities of neutrophils, monocytes and MDMs. Targeting the PGE2 pathway could be a therapeutic approach by which to enhance innate immune function post-injury.

Advantages of Cell Proliferation and Immune Regulation in CD146+NESTIN+ HUMSCs: Insights from Single-Cell RNA Sequencing.

The heterogeneity of stem cells is a significant factor inhibiting their clinical application, as different cell subpopulations may exhibit substantial differences in biological functions. We performed single-cell sequencing on HUMSCs from three donors of different gestational ages (22+5 weeks, 28 weeks, 39 weeks). We also compared the data with single-cell sequencing data from BMSCs from two public databases. The content of CD146+Nestin+ MSCs in preterm HUMSCs (22+5W: 30.2%, 28W: 25.8%) was higher than that in full-term HUMSCs (39W: 0.5%) and BMSCs (BMSC1: 0, BMSC2: 0.9%). Cell cycle analysis indicated a higher proportion of cells in the proliferative G2M phase in CD146+Nestin+ MSCs (40.8%) compared to CD146+Nestin- MSCs (20%) and CD146-Nestin- MSCs (12.5%). Degree of differentiation assessment suggested that CD146+Nestin+ MSCs exhibited lower differentiation than other cell subpopulations. Differential gene analysis revealed that CD146+Nestin+ MSCs overexpressed immune regulation-related factors. GO and KEGG enrichment analysis of modules identified by WGCNA suggested enrichment in pathways related to cellular immune regulation, antimicrobial activity, and proliferation. Immune-related gene analysis indicated that CD146+Nestin+ MSCs exhibited expression of multiple immune-related genes associated with "Antimicrobials," "Cytokines," and "Cytokine Receptors." Gene regulatory network analysis revealed high expression of immune-related regulators RELB, GAPB1, and EHF in CD146+Nestin+ MSCs.Our study provides a single-cell atlas of preterm HUMSCs, demonstrating the expression of CD146+Nestin+ MSCs across different tissues and confirming their advantages in cellular proliferation, antimicrobial activity, immune regulation, and low differentiation at the RNA level. This contributes valuable insights for the clinical application of HUMSCs.

Spots on 1H‐Indazole Incorporation into Thiazole Moiety‐Hybrid Heterocycles, Strong Efficacy as Small Molecules with Antimicrobial, Antineoplastic Activity, and In‐Silico Studies

AbstractAmidst the escalating cancer cases and the relentless spread of multidrug‐resistant microbes, the urgency for effective medication is undeniable. In this context, our lab's continuous efforts have led to a promising discovery. We have conducted an extensive study on a series of new heterocycles with an indazolylthiazole component, which holds great promise as antimicrobial and anticancer drugs. The bioactivity tests, conducted with meticulous methodology, have demonstrated that the synthesized compounds possess remarkable antibacterial activity against various pathogenic strains. In a controlled lab setting, we have observed that derivatives 9, 11, and 12a effectively induce apoptosis in HCT‐166 and Huh‐7 (liver carcinoma) cell lines. Among these, derivative 11 has shown the highest selectivity (SI=14.54±1.2 and 16.51±1.4) and the lowest IC50 value. These compounds also exhibit broad‐spectrum antimicrobial activity. The anticancer activity of the synthesized compounds has been computationally confirmed through molecular modeling using MOE software and pharmacokinetic studies. Most of the tested compounds have shown significant cytotoxic activity against tumor cell lines, with high safety against normal human cells, thereby paving the way for a hopeful and promising future of antimicrobial and anticancer drugs, with potential applications in [specific_application_1] and [specific_application_2].

Antibacterial activity of Savory (Satureja hortensis) extract against pure culture strains of

The paper presents the results of a study of the antibacterial activity of supercritical carbon dioxide extract of the aboveground part of Savory (Satureja hortensis) against Escherichia coli, Salmonella spp. and Staphylococcus aureus bacteria.To study the antibacterial properties of Savory extract (Satureja hortensis) against infections caused by Staphylococcus aureus, Escherichia coli and Salmonella spp.In the course of the experiment, Savory extract obtained by supercritical carbon dioxide extraction was studied for antimicrobial activity against these bacteria. The component composition of the extract was determined by chromatography–mass spectrometry. To determine the antibacterial activity, we used the method of dilution in a liquid medium with subsequent measurement of the growth of the suspension culture biomass. The activity of the extract was compared with certified drugs included in the protocols for the treatment of bacterial infections. DMSO and potassium phosphate buffer were used as a negative control.The studies showed that the extract exhibits high antibacterial activity against all the studied bacterial strains and has a direct positive correlation with its concentration. Chromatographic mass‐spectrometry analysis showed that the extract of garden Savory contains 28 substances, the main ones being thymol (30.51 %), gamma‐terpinene (15.27 %), para‐ cymene (14.25 %) and Carvacrol (9.18 %), which both individually and in combination could exhibit antibacterial activity.Supercritical carbon dioxide extract exhibits pronounced antimicrobial activity against reference strains of S. aureus, Escherichia coli and Salmonella spp.

Studying the Antioxidant and Antimicrobial Activity of Lipsticks Made with Phycoerythrin Under the Influence of Different Magnetic Fields

Background: Several studies have shown the benefits of magnetic treatment on the productivity of secondary metabolites, growth, and the state of microalgae cultures Objective: This study examined the antioxidant and antimicrobial activity of lipsticks made with phycoerythrin (PE) extracted from the cyanobacterium Nostoc sp. under the influence of different magnetic fields (30 mT and 60 mT). Material and Methods: After cyanobacterial culture under magnetic fields of 30 mT and 60 mT, the PE was extracted and lipsticks were formulated. The primary evaluation methods used in this study are melting point, breaking point, linoleic acid peroxidation assay, force of application, stability, surface abnormalities, skin irritation, thixotropy character, dispersibility test, perfume stability, colorimetric assay, antioxidant, and microbial analysis Results: The 30 mT treatment showed the highest concentration, purity, dry weight, antioxidant activity, and percentage of PE extraction compared to control cultures. No significant differences were found in the melting point, stability, thixotropy character, dispersibility, or perfume stability tests. The breaking point and force of application decreased significantly during 30 days. Peroxidation assay tests revealed lipstick increased oxidation and antioxidant activity after 30 days of 30 and 60 mT treatments compared to non-PE cultures. The study found that the amount of ΔE increased significantly in cultures without PE over time, while this increase was lower in magnetic field-treated cultures. However, no signs of crystal formation, surface wrinkles, liquid secretion, itching, or skin irritation were observed in 30 days of 30 and 60 mT magnetic treatments compared to control cultures with PE. Microbial analyzes over 30 days showed a significantly lower number of bacteria under magnetic fields than control cultures. In addition, the results of counting Escherichia coli and coliform bacteria were negative for thirty days. The antioxidant activity of PE was significantly higher in magnetic field-treated cultures. The number of Staphylococcus aureus decreased significantly in all cultures under magnetic field influence. Conclusions: The overall results of this study showed that magnetic fields had a significant effect in many evaluation tests on the culture of cyanobacteria Nostoc sp. As a result, lipsticks made with extracted PE have more antioxidant and antimicrobial activity

Phyllanretiosides A and B: Two Undescribed Compounds from Phyllanthus Reticulatus with Nitric Oxide Production Inhibition and Antimicrobial Activity.

Phytochemical study on the methanol extract of the leaves of Phyllanthus reticulatus led to the isolation of two new compounds, phyllanretiosides A (1) and B (2) together with ten known ones (3-12). Their chemical structures were determined by HR-ESI-MS, NMR, and ECD spectra in comparison with the literature. Three ellagitannins, phyllanretioside A (1), corilagin (3), and phyllanthusiin C (4) inhibited lipopolysaccharide(LPS)-induced nitric oxide production in RAW 264.7 cells with IC50 values of 63.2, 83.2, and 5.6 μM, respectively. In addition, compounds 1, 3, and 4 exhibited significantly antimicrobial activity (MICs: 16-128 μg/mL) towards some of seven microbial strains.

Synthesis, Biological Evaluation, andMolecular Docking Studies of Indole-Based Heterocyclic Scaffolds as Potential Antibacterial Agents.

This study aimed to synthesize C3-indole derivatives linked to various heterocyclic scaffolds, including thiophenes, thiazolidine-4-ones, and 1,3,4-thiadiazoles, via the reaction of ethylthioacetanilide 2 with different α-haloketones.The structures of the target compounds were established using 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, infrared spectroscopy, and elemental analysis. The synthesized compounds were tested for antimicrobial activity against different microbes: S. aureus ATCC 6538 (Gram-positive bacteria), E. coli ATCC 25933 (Gram-negative bacteria), C. albicans ATCC 10231 (yeast), and fungi (A. niger NRRL-A326). Thiophene 6a, thiazolidine-4-one 8, and compound 10d exhibited the highest antimicrobial activities. The molecular docking study showed that compounds 2, 4, 6a, and 6c had good binding energy and favorable binding modes of interactions with the DNA gyrase B enzymes (PDB: 3U2D) and (PDB: 1S14). The results showed that the NH group of the indole in compounds 2 and 4, together with the nitrile group (CN), played an important role in inhibiting DNA gyrase B of S. aureus, PDB: 3U2D. Furthermore, the NH of the indole ring, together with the ethylamino group of compound 2, was crucial in inhibiting DNA gyrase B of E. coli, PDB: 1S14. These results could inspire further development of indole derivatives as antimicrobial drugs.

In Vitro Assessment of Gallium Nanoalloy Hydrogels for Antimicrobial and Wound Healing Applications.

Chronic and recurring wounds pose a significant challenge in modern healthcare, leading to substantial morbidity. These wounds allow pathogens to colonize, potentially resulting in local and systemic infections. Current interventions need to be revised and become increasingly less reliable due to the emergence of antibiotic resistance. In the present study, we aim to address these issues by fabricating hydrogels impregnated with gallium-based nanoalloys for their antimicrobial activity. Gallium liquid metal nanoparticles (approximately 100 nm in diameter) were alloyed in different combinations with bismuth and silver ions through a galvanic replacement reaction. These multimetallic hydrogels showed favorable antibacterial activity against the Gram-positive Staphylococcus aureus and the Gram-negative Pseudomonas aeruginosa, as observed with fluorescence microscopy and inhibition assays. The multimetallic hydrogels showed no toxicity against murine macrophages or human dermal fibroblasts and enhanced in vitro wound healing. The development of these innovative gallium-based hydrogels represents a promising strategy to combat chronic wounds and their associated complications, offering an effective alternative to current antimicrobial treatments amidst rising antibiotic resistance.

Validation of ethnopharmacological findings of Aegle marmelos (L.) Correa through phytochemical screening and bioactivity assay

For centuries, medicinal plants have been integral to human health and well-being across the world. Aegle marmelos (Rutaceae), a medicinal plant indigenous to Nepal, holds substantial ethnomedicinal use among indigenous communities in South Asian countries. Present study aimed to explore the integration of contemporary scientific analysis of the phytochemical composition and bioactivity of A. marmelos leaf extracts harvested from Nepal with traditional ethnopharmacological knowledge. Leaf extracts of A. marmelos were subjected to phytochemical analysis utilizing mass spectrometry. The extracts underwent in vitro evaluation for antimicrobial, antidiabetic, antioxidant, and toxicity activities. Hexane fraction was found to possess volatile oils, polyphenols, and tannins, while other fractions were found to have alkaloids, terpenoids, coumarins, flavonoids, glycosides, saponins, and reducing sugars. Further analysis of the hexane fraction identified 21 compounds with over 90 % accuracy. The main phytoconstituents were 9,12,15-octadecatrienoic acid methyl ester (24.25 %), hexadecanoic acid (10.89 %), methylcyclohexane (8.39 %), methyl ester (4.26 %), and caryophyllene (4.10 %). The methanol extract exhibited significant antibacterial activity against Staphylococcus aureus and Escherichia coli. Additionally, the methanol extract demonstrated pronounced cytotoxic effects against brine shrimp, with an LC50 value of 50.11 µg/mL. The 1,1-diphenyl-2-picryl hydrazyl assay revealed both methanol and acetone extract to have notable antioxidant activity, with IC50 values of 90.63 ± 1.47 µg/mL and 89.93 ± 2.52 µg/mL, respectively. Remarkably, the acetone extract displayed superior antidiabetic activity compared to acarbose, with an IC50 value of 13.50 ± 0.79 µg/mL. Our findings proves A. marmelos leaf extracts to harbor significant bioactive constituents, suggesting their potential as sources of natural compounds for applications in medicine and healthcare.

Phytochemical composition, antimicrobial, antioxidant, and wound healing activities of Thermopsis turcica.

The antioxidant, antimicrobial, anticarcinogenic, wound healing activities and phenolic substance profile of aqueous extracts prepared using branch, leaf, flower parts and above-ground parts of Thermopsis turcica were determined in the study. The analyses indicate that the total phenolic substance contents and total antioxidant status are higher in the mix, flower, and leaf extracts. The extracts reduced cell viability in HGF cells more than in A549 cells. It shows that the extract has low anticarcinogenic activity in A549 cells. Flower extract had the highest wound closure rate. Quinic acid, cyranoside and luteolin were found in high concentrations in all extracts with LC/ESI-MS/LC analysis. It has been determined that the flower extract of the species is the most critical part showing antioxidant, antimicrobial, cytotoxic and wound healing properties. While the leaf and mix extracts stand out with their antioxidative and antimicrobial properties, the branch extract is effective in wound healing.

The Wheel of Fortune: Helical Wheel Alanine Scanning of a Spider Venom Antimicrobial Peptide Reveals Residues Involved in Antimicrobial and Cytotoxic Activity.

A preference for several amino acids is observed to occur at particular positions of cationic α-helical antimicrobial peptides (AMPs), which ensures the formation of amphipathic regions once they assume their correct secondary structure in membranes or membrane-mimicking environments and makes them active against pathogens. This study determined the effect of alanine mutations on the secondary structure and bioactivity of lyp1987 (GRLQAFLAKMKEIAAQTL-NH2), a cationic α-helical AMP obtained from the venom of Lycosa poonaensis which exhibits broad range activity against Gram-positive and Gram-negative bacteria with micromolar minimum inhibitory concentrations (MIC). CD spectroscopy revealed no significant difference in the secondary structure, with all alanine-substituted analogs exhibiting predominantly α-helical structure in buffered 2,2,2-trifluoroethanol solution. Alanine substitution at Glu12 and Thr17 increased the activity of lyp1987 against Gram-positive and -negative bacteria, while alanine substitution at Lys9 increased its selectivity against Gram-positive bacteria. Further investigation can be done to determine positions and substitutions that will give less cytotoxic analogs.

Lactoferrin: a secret weapon in the war against pathogenic bacteria

The excessive use of antibiotics to treat bacterial infectious diseases in all living beings has caused a global epidemic of bacterial resistance to antibiotics, leading to the emergence of multidrug-resistant and pandrug-resistant strains. In 2019, the World Health Organization (WHO) reported that antimicrobial resistance causes at least 700,000 deaths per year worldwide. Therefore, in this global war against microorganisms, a therapeutic alternative is necessary to help us win this battle. A key in this race against the clock could be lactoferrin (Lf), a cationic glycoprotein of the mammalian innate immune system that is highly conserved among mammals. Lf is a multifunctional glycoprotein with immunomodulatory, anticarcinogenic, wound-healing, antioxidant, antimicrobial, and bone regeneration properties, in addition to improving the gut microbiota. Lf limits the growth of microorganisms through the sequestration of iron but can also interact directly with some components of the outer membrane of Gram-negative bacteria or bind to teichoic acids in Gram-positive bacteria, destabilizing the membrane and resulting in lysis. Moreover, cleavage of the Lf molecule could promote the production of lactoferricins (Lfcins) and lactoferrampin (Lfampin) from the N-terminal end, which are known to often have stronger antimicrobial effects than the native molecule, as well as analogous peptides, such as HLopt2, which have also shown enhanced antimicrobial activity. Bovine Lf (bLf) has been approved by the US Food and Drug Administration (FDA), and the European Food Safety Authority for its use as a dietary supplement in food products. Because of its effectiveness, accessibility, low cost, and nontoxicity, Lf could be a promising alternative for preventing or treating infections in animals and humans.

In vitro antimicrobial activity of non-traditional therapies for infectious endometritis in mares.

Endometritis is the leading cause of subfertility in horses, and it is a clinical problem where historically antibiotics have not always been used with prudent justification. Because of this, alternative therapies to treat endometritis are necessary for the rational use of antibiotics. To assess the in vitro antimicrobial activity of non-traditional therapies commonly used in clinical practice against microorganisms causing infectious endometritis in mares. In vitro experiments. A microdilution technique was performed to determine the minimum inhibitory concentrations (MIC) of 50%, 90% and 100% of microorganisms and the percentage of inhibition (PI) of each therapy against each microorganism (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Candida sp.). The MIC 50% and 90% were determined using non-linear regression, while MIC 100% was assessed using the resazurin dye technique. The serial PI was evaluated for each therapy using a spectrophotometer. All the therapies demonstrated a PI higher than positive controls for all microorganisms (p < 0.05); however, the only therapies that presented MIC 100 values were hydrogen peroxide and platelet-rich and -poor plasma. In vivo, safety and treatment efficacy were not tested. Hydrogen peroxide and platelet-rich and -poor plasma might be alternatives to traditional therapies for endometritis to support a reduction in antibiotic use.

MLKL promotes extracellular trap releasing in Vibrio splendidus AJ01-challenged coelomocytes of sea cucumber Apostichopus japonicus

Extracellular traps (ETs) is a novel host-defense mechanism for the immobilization and killing of invading microorganisms, of which pseudokinase mixed lineage kinase-like protein (MLKL) is necessary for ET formation. Here, we aimed to investigate the effects of various stimulations (including classic ET inducers and pathogen) on ET formation in the coelomocytes of invertebrate sea cucumber Apostichopus japonicus. Our results show that stimulation of sea cucumber coelomocytes with phorbol 12-myristate 13-acetate (PMA), zymosan, Vibrio splendidus AJ01, and AJ01 flagella all led to the formation of typical ET fibers, which can be further digested by DNase I. This finding suggests that DNA is an essential component of coelomocyte ETs. Meanwhile, the signals of histones H2A and H2B transferred to extracellular spaces and colocalized with AJ01, which indicates that histones are also crucial components of coelomocyte ETs. Scanning electron microscopy observation and antimicrobial activity analysis successfully revealed that AJ01 was trapped and killed by ET fibers, and this finding implies the antimicrobial role of sea cucumber coelomocyte ETs. More importantly, silencing and inhibition of AjMLKL after AJ01 infection not only considerably depressed ET generation but also increased the survival rate of AJ01. All our results indicate that AjMLKL mediates sea cucumber ET formation and plays critical roles during pathogen infection.

Endophytic bacteria in Camellia reticulata pedicels: isolation, screening and analysis of antagonistic activity against nectar yeasts

Camellia reticulata, an ancient plant species endemic to Yunnan Province, China, remains underexplored in terms of its endophytic bacterial communities. The plant tissue pedicel serves as the connection between the flower and the stem, not only delivers nutrients but also transmits metabolic substances from endophytic bacteria to the nectar during long-term microbial colonization and probably improves the antagonistic activity of nectar against yeast. Hence, 138 isolates of endophytic bacteria have been isolated in this study from the pedicels of 12- and 60-year-old C. reticulata. Comparative analysis revealed significantly higher density of endophytic bacteria in older trees. Among these isolates, 29 exhibited inhibitory effects against nectar yeasts. Most of the isolates displayed positive results for Gram staining, catalase reaction, gelatin liquefaction, and motility. Additionally, the isolates demonstrated the ability to utilize diverse substrates, such as glucose, nitrate, and starch. Based on 16S rRNA molecular biology analysis, these isolates were identified to be 11 different species of 6 genera, with the majority belonging to Bacillus genus. Notably, C1 isolate, identified as Bacillus spizizenii, exhibited strongest antagonistic effect against three yeasts, i.e., Metschnikowia reukaufii, Cryptococcus laurentii, and Rhodotorula glutinis, with minimum inhibitory concentration values below 250 μg/mL. Major metabolites of B. spizizenii were aminoglycosides, beta-lactams, and quinolones, which possess antimicrobial activities. Furthermore, KEGG enrichment pathways primarily included the synthesis of plant secondary metabolites, phenylpropanoids, amino acids, alkaloids, flavonoids, neomycin, kanamycin, and gentamicin. Therefore, antagonistic activity of B. spizizenii against yeasts could be attributed to these antibiotics. The findings highlight the diverse endophytic bacteria associated with C. reticulata, indicating their potential as a valuable resource of bioactive metabolites. Additionally, this study provides new insights into the role of endophytic bacteria of pedicels in enhancing nectar resistance against yeasts.

ω‐Aminomethyl Longifolene Amide Derivatives: Synthesis, Crystal Structure, Hirshfeld Surface, DFT, Antimicrobial, and Molecular Docking Studies

AbstractTwelve novel ω‐aminomethyl longifolene amide derivatives (6 a–6 l) were synthesized and characterized. The intermolecular contacts and the relationship of structure‐property for the synthesized compounds were performed with the use of two‐dimensional fingerprint plots and Hirshfeld surface method. Moreover, the chemical reactivity and geometrical characteristics of target compounds were investigated using density functional theory (DFT) method. Molecular docking studies were performed to investigate the interactions between compounds 6 a–6 l and sortase A (SrtA) from S. aureus, the carboxy terminal domain of colicin E5 (E5‐CRD) and Serine/Threonine phosphatase Z1 (PPZ1) from C. albicans, respectively, and together with their biological activities. The docking results of the synthesized compounds 6 a–6 l showed different binding efficiencies and inhibitory effects on S. aureus, E. coli and C. albicans. Furthermore, preliminary antimicrobial activity assay showed that compounds 6 f, 6 i and 6 k exhibited comparable or superior antibacterial activity against S. aureus, B. subtilis and K. pneumoniae compared to rifampicin with minimum inhibitory concentration (MIC) values from 0.488 to 0.977 μg/mL. In addition, the absorption, distribution, metabolism and excretion (ADME) and drug‐likeness properties of the synthesized derivatives were evaluated as well.

Dual-Action Gemcitabine Delivery: Chitosan–Magnetite–Zeolite Capsules for Targeted Cancer Therapy and Antibacterial Defense

Cancer and infectious diseases are two of the world’s major public health problems. Gemcitabine (GEM) is an effective chemotherapeutic agent against several types of cancer. In this study, we developed macrocapsules incorporating GEM into a chitosan matrix blended with magnetite and zeolite by ionic gelation. Physicochemical characterization was performed using HRTEM-ED, XRD, FESEM–EDS, FT-IR, TGA, encapsulation efficiency (%E.E.), and release profiles at pHs 7.4 and 5.0. Cell viability tests against A549 and H1299 cell lines, and microbiological properties against staphylococcal strains were performed. Our results revealed the successful production of hemispherical capsules with an average diameter of 1.22 mm, a rough surface, and characteristic FT-IR material interaction bands. The macrocapsules showed a high GEM encapsulation efficiency of over 86% and controlled release over 24 h. Cell viability assays revealed that similar cytotoxic effects to free GEM were achieved with a 45-fold lower GEM concentration, suggesting reduced dosing requirements and potentially fewer side effects. Additionally, the macrocapsules demonstrated potent antimicrobial activity, reducing Staphylococcus epidermidis growth by over 90%. These results highlight the macrocapsules dual role as a chemotherapeutic and antimicrobial agent, offering a promising strategy for treating lung cancer in patients at risk of infectious diseases or who are immunosuppressed.

Screening of antimicrobial activity in venom: Exploring key parameters

The escalating challenge of antibiotic resistance significantly threatens global health, underscoring the critical need for new antimicrobial agents. Venoms, increasingly recognized as reservoirs of bioactive compounds with diverse pharmacological effects, have been the focus of recent research. This work evaluates the use of various screening methodologies in assessing the antimicrobial activities of 185 venoms against some gram positive and gram negative bacteria, including E. coli ATCC 8739, B. subtilis ATCC 6633, P. aeruginosa ATCC 9027, and S. aureus ATCC 6538P species and explores the influence of settings on the findings. Furthermore, the research explored the possibility of purifying antimicrobial molecules from venoms through HPLC. Several fractions demonstrated antimicrobial activity against the tested strains.Our results reveal that the measured antimicrobial efficacy of venoms varies according to:i) venom concentration, ii) the detection method, including microdilution and radial diffusion assays, and iii) the choice of culture medium, specifically LB or MH.This strategy has allowed us, for the first time, to identify antimicrobial activity in: i) Bitis arietans venom against P. aeruginosa ATCC 9027, ii) Naja nubiae and Bothrops lanceolatus against B. subtilis ATCC 6633, P. aeruginosa ATCC 9027, and S. aureus ATCC 6538P, and iii) Hadogenes zuluanus, Mesobuthus caucasicus, Nebo hierichonticus, Opistophthalmus wahlbergii scorpions, and Mylabris quadripunctata beetles against S. aureus ATCC 6538P.These findings highlight venoms potential as effective antimicrobial resources and improve our understanding of key factors critical for an accurate detection of venoms antimicrobial properties.

Evaluation of the Enzyme Inhibition, Antioxidant, and Antimicrobial Activities of Apricots, Plums, and Their Hybrid Fruits

The current study focuses on evaluating the enzyme inhibition (acetylcholinesterase, α-amylase, α-glucosidase, pancreatin lipase), antioxidant, and antimicrobial activities of the “Modesto” apricot, “Stanley” plum, and their hybrid the “Stendesto” plum–apricot. The “Stendesto” is the only successful plum–apricot hybrid in Bulgaria. A spectrophotometric approach was used to evaluate the antioxidant activity following four complementary assays (DPPH, ABTS, FRAP, and CUPRAC). The “Stendesto” plum–apricot revealed its enhanced antioxidant potential compared to its parental lines. Apart from the free phenolics extraction, two other techniques (alkaline and acid hydrolysis) were applied to reveal the biological potential of the studied fruit. Not only free but also bound phenolic extracts were able to inhibit α-glucosidase and acetylcholinesterase, while none of the extracts inhibited lipase or α-amylase. None of the apricot extracts had antimicrobial activity, while the other fruit had limited antimicrobial activity. The proposed results undoubtedly reveal that hybrid fruits possess enhanced biological activity compared to their parents. This is a first comprehensive evaluation of hybrid fruits with reference to parental lines. This makes them an interesting research topic that should be better explored.

Synthesis of a Quaternary Ammonium-Halamine and Preparation on the Modified Nanofibrous Filter with Superior Sterilization, Air Filtration, and Biodegradability.

The outbreak of the 2019 coronavirus pandemic has raised worldwide attention about self-protection from airborne diseases. Air filtration and wearing mask have been proven to be effective measures in reducing the pathogenic aerosol's transmission. Those lead to an increasing demand of high-efficient filters. However, the nonbiodegradable polymeric materials used in filters can accumulate in landfills or ecosystems, potentially causing pollution after improper disposals. Sustainable and biodegradable alternatives to current filter materials are urgently needed. Yet, very few commercial filters meet these needs. In this paper, a novel quaternary ammonium-halamine compound containing Schiff base and a sandwich-structured preparation strategy were developed. The obtained multifunctional filter consists of a PLA fleece as a support layer, an antimicrobial coating for bactericidal function, and a nanofibrous membrane for the particle removal. The filter demonstrates strong bactericidal properties, killing 97% of Escherichia coli and Staphylococcus aureus at a biocide concentration of only 1 mg/mL. It can rapidly kill bacteria within 5 min contact without leaching antimicrobial substances. Furthermore, it boasts a filtration performance with a success rate over 99.99% and a pressure drop of 45 Pa, which surpasses that of commercial N95 filters for PM0.3. Even under humid conditions, it maintains excellent filtration performance. Our reusability testing result of the developed filters shows that a simple halogenation treatment can renew the halamines and restore the filter's antimicrobial activity. The filters can degrade in natural soil. The successful development of this sustainable and biodegradable filter material offers a new alternative for high-performance air quality control that protect public health.