Potent Antimicrobial Effects Research Articles

Physico-Chemical Investigation and Antimicrobial Efficacy of Ozonated Oils: The Case Study of Commercial Ozonated Olive and Sunflower Seed Refined Oils.

Drug resistance represents one of the great plagues of our time worldwide. This largely limits the treatment of common infections and requires the development of new antibiotics or other alternative approaches. Noteworthy, the indiscriminate use of antibiotics is mostly responsible for the selection of mutations that confer drug resistance to microbes. In this regard, recently, ozone has been raising interest for its unique biological properties when dissolved in natural oils. Ozonated oils have been reported to act in a non-specific way on microorganisms hindering the acquisition of advantageous mutations that result in resistance. Here, we focused on the antimicrobial effect of two commercial olive (OOO) and sunflower seeds (OSO) oils. Nuclear magnetic resonance spectroscopy and thermal analysis showed the change in the chemical composition of the oils after ozonation treatment. Different ozonated oil concentrations were then used to evaluate their antimicrobial profile against Candida albicans, Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli by agar diffusion and broth dilution methods. Cytotoxicity was also evaluated in keratinocytes and epithelial cells. Overall, our results revealed that both OOO and OSO showed a potent microbicidal effect, especially against C. albicans (IC50 = OOO: 0.3 mg/mL and OSO: 0.2 mg/mL) and E. faecalis (IC50 = OOO: 0.4 mg/mL and OSO: 2.8 mg/mL) albeit exerting a certain effect also against S. aureus and E. coli. Moreover, both OOO and OSO do not yield any relevant cytotoxic effect at the active concentrations in both cell lines. This indicates that the ozonated oils studied are not toxic for mammalian cells despite exerting a potent antimicrobial effect on specific microorganisms. Therefore, OOO and OSO may be considered to integrate standard therapies in the treatment of common infections, likely overcoming drug resistance issues.

Synthesis, antimicrobial activity and application of polymers of praseodymium complexes based on pyridine nitrogen oxide.

The traditional pyridine nitrogen oxide-based antimicrobial agents are often associated with health risks due to heavy metal enrichment. To mitigate this concern, we synthesized two novel complexes, Pr2(mpo)6(H2O)2 and Pr(hpo)(mpo)2(H2O)2, and integrated rare-earth salts, Hhpo (2-hydroxypyridine-N-oxide) and Nampo (2-mercapto-pyridine-N-oxide sodium salt). These complexes were characterized through infrared analysis, elemental analysis, thermogravimetric analysis, and X-ray crystallographic analysis. Our comparative analyses demonstrate that the synthesized rare-earth complexes exhibit stronger antimicrobial activity against Staphylococcus aureus (S. aureus ATCC6538) and Escherichia coli (E. coli ATCC25922) compared to the ligands and rare-earth salts alone. Quantitative results revealed the lowest inhibitory concentrations of the two complexes against S. aureus ATCC6538 and E. coli ATCC25922 at 3.125 μg mL-1, 6.25 μg mL-1, 3.125 μg mL-1 and 6.25 μg mL-1, respectively. Preliminary investigations indicated that the antibacterial mechanism of these complexes involved promoting intracellular substance exudation to achieve antibacterial effects. Incorporation of these complexes into polymeric antimicrobial films resulted in a potent antimicrobial effect, achieving a 100% inhibition rate against S. aureus ATCC6538 and E. coli ATCC25922 at a low addition level of 0.6 wt%. Our results suggest that nitrogen oxide-based praseodymium complexes have potential for various antimicrobial applications.

Investigation of Antimicrobial, Antioxidant, and Cytotoxic Activities of Boesenbergia rotunda rhizome extract

In recent years, antimicrobial resistance (AMR) has become a global threat to public health. In Hawai’i, there is an increasing rate of staph infections of methicillin-resistant Staphylococcus aureus (MRSA), and, hence, a need for new agents to combat the increase of AMR bacteria. This study evaluates the antimicrobial, antioxidant, and cytotoxic activities of Hawaiian-grown Boesenbergia rotunda. Test bacteria included clinical isolates of Gram-positive MRSA and methicillin-susceptible S. aureus (MSSA) as well as Gram-negative Serratia marcescens and Escherichia coli. Five compounds–cardamonin, pinostrobin, pinocembrin, pinostrobin chalcone, and isopanduratin A–were isolated from the ethyl acetate extract of B. rotunda rhizome, and their structures were identified by NMR spectroscopy. These samples exhibited antimicrobial activity against MRSA and MSSA strains, with minimum inhibitory concentration (MIC) values between 128 and 2 µg/mL, with isopanduratin A giving MIC values as low as 2 µg/mL. The antioxidant potential of samples was examined using ferric-reducing antioxidant power (FRAP) assay. At 1 mg/mL of tested samples, FRAP values ranged between 8.74 to 17.76 µM/µg, with pinostrobin chalcone exhibiting the highest FRAP value (17.76 ± 0.65 μM/μg). Moreover, cytotoxicity was measured via sulforhodamine B (SRB) assay. Cardamonin (IC50 of 19.43 ± 0.33 μM) and isopanduratin A (IC50 of 26.84 ± 1.06 μM) exhibited effectiveness against the lung cancer cell line A549. Compounds from B. rotunda showed potent antimicrobial effect against MRSA and MSSA strains as well as antioxidant and cytotoxic activities, and may have the potential for further evaluation and development for pharmaceutical applications.

Evaluation of the antimicrobial potential of digested and undigested carob phenolic extracts: Impact on selected gut microbiota

AbstractCarob pulp is a natural source of polyphenols, which have been shown to possess health benefits. These compounds play a crucial role in initiating, shaping, and modulating the gut microbiota. The objective of this study was to evaluate the impact of carob pulp phenolic extracts on nine specific groups of human gut microbiota before and after in vitro gastrointestinal digestion. The effects of pure gallic and coumaric acids were also tested. The results showed that the treated phenolic compounds exhibited inhibitory effects on the growth of most pathogenic bacteria. Gallic acid, in particular, demonstrated the most potent antimicrobial effect on Listeria monocytogenes, reducing its growth to below 5%. Staphylococcus aureus and Escherichia coli showed a growth reduction of up to 10%. Furthermore, both phenolic acids, before and after digestion, led to a slight reduction in E. coli O157:H7 numbers. Probiotic bacteria experienced minimal decrease following exposure to phenolic extracts. However, the growth of Lactobacillus casei ssp. rhamnosus was significantly inhibited by almost 50%. Interestingly, the in vitro digestion process exhibited a stronger antibacterial effect against pathogenic bacteria compared to probiotic bacteria. These results highlight the potential of carob phenolic extracts in modulating the intestinal microbiota, thereby offering interesting prospects for the development of diet-based health strategies.

Solanum lycopersicum heme-binding protein 2 as a potent antimicrobial weapon against plant pathogens

The rise in antibiotic-resistant bacteria caused by the excessive use of antibiotics has led to the urgent exploration of alternative antimicrobial solutions. Among these alternatives, antimicrobial proteins, and peptides (Apps) have garnered attention due to their wide-ranging antimicrobial effects. This study focuses on evaluating the antimicrobial properties of Solanum lycopersicum heme-binding protein 2 (SlHBP2), an apoplastic protein extracted from tomato plants treated with 1-Methyl tryptophan (1-MT), against Pseudomonas syringae pv. tomato DC3000 (Pst). Computational studies indicate that SlHBP2 is annotated as a SOUL heme-binding family protein. Remarkably, recombinant SlHBP2 demonstrated significant efficacy in inhibiting the growth of Pst within a concentration range of 3–25 μg/mL. Moreover, SlHBP2 exhibited potent antimicrobial effects against other microorganisms, including Xanthomonas vesicatoria (Xv), Clavibacter michiganensis subsp. michiganensis (Cmm), and Botrytis cinerea. To understand the mechanism of action employed by SlHBP2 against Pst, various techniques such as microscopy and fluorescence assays were employed. The results revealed that SlHBP2 disrupts the bacterial cell wall and causes leakage of intracellular contents. To summarize, the findings suggest that SlHBP2 has significant antimicrobial properties, making it a potential antimicrobial agent against a wide range of pathogens. Although further studies are warranted to explore the full potential of SlHBP2 and its suitability in various applications.

Dual-Activity Fluoroquinolone-Transportan 10 Conjugates offer alternative Leukemia therapy during Hematopoietic Cell Transplantation.

Hematopoietic cell transplantation (HCT) is often considered a last resort leukemia treatment, fraught with limited success due to microbial infections, a leading cause of mortality in leukemia patients. To address this critical issue, we explored a novel approach by synthesizing antileukemic agents containing antibacterial substances. This innovative strategy involves conjugating fluoroquinolone antibiotics, such as ciprofloxacin (CIP) or levofloxacin (LVX), with the cell-penetrating peptide (CPP) transportan 10 (TP10). Here, we demonstrate that the resultant compounds display promising biological activities in preclinical studies. These novel conjugates not only exhibit potent antimicrobial effects but are also selective against leukemia cells. The cytotoxic mechanism involves rapid disruption of cell membrane asymmetry leading to membrane damage. Importantly, these conjugates penetrated mammalian cells, accumulating within the nuclear membrane without significant effect on cellular architecture or mitochondrial function. Molecular simulations elucidated the aggregation tendencies of TP10 conjugates within lipid bilayers, resulting in membrane disruption and permeabilization. Moreover, mass spectrometry analysis confirmed efficient reduction of disulfide bonds within TP10 conjugates, facilitating release and activation of the fluoroquinolone derivatives. Intriguingly, these compounds inhibited human topoisomerases, setting them apart from traditional fluoroquinolones. Remarkably, TP10 conjugates generated lower intracellular levels of reactive oxygen species (ROS) compared to CIP and LVX. The combination of antibacterial and antileukemic properties, coupled with selective cytostatic effects and minimal toxicity towards healthy cells, positions TP10 derivatives as promising candidates for innovative therapeutic approaches in the context of antileukemic HCT. This study highlights their potential in search of more effective leukemia treatments. Significance Statement Fluoroquinolones are commonly used antibiotics, while TP10 is a CPP with anticancer properties. In HCT, microbial infections are the primary cause of illness and death. Combining TP10 with fluoroquinolones enhanced their effects on different cell types. The dual pharmacological action of these conjugates offers a promising proof-of-concept solution for leukemic patients undergoing HCT. Strategically designed therapeutics, incorporating CPPs with antibacterial properties, have the potential to reduce microbial infections in the treatment of malignancies.

A potential strategy against clinical carbapenem-resistant Enterobacteriaceae: antimicrobial activity study of sweetener-decorated gold nanoparticles in vitro and in vivo

BackgroundCarbapenem-resistant Enterobacteriaceae (CRE) present substantial challenges to clinical intervention, necessitating the formulation of novel antimicrobial strategies to counteract them. Nanomaterials offer a distinctive avenue for eradicating bacteria by employing mechanisms divergent from traditional antibiotic resistance pathways and exhibiting reduced susceptibility to drug resistance development. Non-caloric artificial sweeteners, commonly utilized in the food sector, such as saccharin, sucralose, acesulfame, and aspartame, possess structures amenable to nanomaterial formation. In this investigation, we synthesized gold nanoparticles decorated with non-caloric artificial sweeteners and evaluated their antimicrobial efficacy against clinical CRE strains.ResultsAmong these, gold nanoparticles decorated with aspartame (ASP_Au NPs) exhibited the most potent antimicrobial effect, displaying minimum inhibitory concentrations ranging from 4 to 16 µg/mL. As a result, ASP_Au NPs were chosen for further experimentation. Elucidation of the antimicrobial mechanism unveiled that ASP_Au NPs substantially elevated bacterial reactive oxygen species (ROS) levels, which dissipated upon ROS scavenger treatment, indicating ROS accumulation within bacteria as the fundamental antimicrobial modality. Furthermore, findings from membrane permeability assessments suggested that ASP_Au NPs may represent a secondary antimicrobial modality via enhancing inner membrane permeability. In addition, experiments involving crystal violet and confocal live/dead staining demonstrated effective suppression of bacterial biofilm formation by ASP_Au NPs. Moreover, ASP_Au NPs demonstrated notable efficacy in the treatment of Galleria mellonella bacterial infection and acute abdominal infection in mice, concurrently mitigating the organism's inflammatory response. Crucially, evaluation of in vivo safety and biocompatibility established that ASP_Au NPs exhibited negligible toxicity at bactericidal concentrations.ConclusionsOur results demonstrated that ASP_Au NPs exhibit promise as innovative antimicrobial agents against clinical CRE.Graphical

Antioxidant, Antimicrobial, and Insecticidal Properties of Chemically Characterized Essential Oils Extracted from Mentha longifolia: In Vitro and In Silico Analysis.

The present study aimed to explore the phytochemical profile, and evaluate the antioxidant, antimicrobial, and insecticidal properties, of Moroccan Mentha longifolia L. essential oil (ML-EO) using in vitro and in silico assays. Noteworthily, as chromatography (GC-MS/MS) revealed that ML-EO is majorly composed of piperitenone oxide (53.43%), caryophyllene (20.02%), and (-) germacrene D (16.53%). It possesses excellent antioxidant activity with an IC50 of 1.49 ± 0.00 for DPPH and 0.051 ± 0.06 μg/mL for ABTS. Moreover, the RP and TAC activities were 0.80 ± 0.01 μg/mL and 315.532 ± 0.00 mg EAA/g, respectively. ML-EO exhibited a potent antimicrobial effect, specifically against Pseudomonas aeruginosa. It also exhibited strong antifungal ability, especially against Candida albicans. Regarding insecticidal activity, for ML-EO, a dose of 20 µL/mL produced a complete reduction in fecundity, fertility, and emergence of adult C. maculatus with mortality rates reaching 100%. In silico results showed that the antioxidant activity is mostly attributed to α-Cadinol, the antibacterial efficiency is attributed to piperitenone oxide, and antifungal capacity is related to cis-Muurola-4(15),5-diene and piperitenone oxide. Accordingly, ML-EO has high potential to be used as an alternative for preserving food and stored grain and protecting them against microbes and insect pests in the food and pharmaceutical sectors.

Unravelling the Secrets of α-Pyrones from Aspergillus Fungi: A Comprehensive Review of Their Natural Sources, Biosynthesis, and Biological Activities.

Aspergillus, one of the most product-rich and genetically robust genera, contains a diverse range of species with potential economic and ecological implications. Chemically, Aspergillus is one of the essential sources of polyketides, alkaloids, diphenyl ethers, diketopiperazines, and other miscellaneous compounds, displaying a variety of pharmacological activities. The α-pyrones are unsaturated six-membered lactones. Although α-pyrone has a small structure, it is responsible for the structural diversity of several natural and synthetic compounds and multiple biological activities. In this review, we have summarized approximately 178 α-pyrone containing metabolites derivatives identified/reported from terrestrial, marine, endophytic, and filamentous Aspergillus species, including their sources, biological properties, and biosynthetic pathways until mid-2023, for the first time. This review is the first to compile and analyze the available data on α-pyrone metabolites from Aspergillus, which could facilitate further research and innovation in this field. Additionally, it offers a valuable source of scaffolds for future bioactive drug development, as some of these metabolites have shown potent antimicrobial, anti-inflammatory, and anticancer effects. Therefore, this review has significant implications for the advancement of natural product chemistry, pharmacology, biotechnology, and medicine.

Lactoferrin's potential application in enhancing yoghurt's microbial and sensory qualities, with emphasis on the starter culture activity.

This research paper aimed to examine the antibacterial activity of lactoferrin (LF) as a potential natural alternative in the dairy sector, by measuring its minimum inhibitory concentration (MIC) against a number of common food-borne pathogens as well as Pseudomonas aeruginosa, one of the major dairy product spoiling microorganisms. Additionally, a viability experiment was applied to laboratory-manufactured set yoghurt to assess its impact on the activity of starter culture, sensory properties and STEC survivability. The findings demonstrated that LF exhibited significant antimicrobial activity, particularly against E. coli and S. typhimurium with MIC values of 0.0001 and 0.01 mg/ml, respectively. However, P. aeruginosa and B. cereus were quite resistant to LF requiring higher concentrations for MIC (2.5 mg/ml). By the third day of storage, LF at 0.0001 and 0.001 mg/ml significantly reduced the survivability of Shiga toxin-producing E. coli STEC by 70 and 91.6%, respectively, in the lab-manufactured yoghurt. Furthermore, LF enhanced the sensory properties of fortified yoghurt with a statistically significant difference in comparison to the control yoghurt group. There was no interference with the activity of the starter culture throughout the manufacturing process and the storage period. In conclusion, the potent antimicrobial effect of LF opens a new avenue for the dairy industry's potential applications of LF as a natural preservative without negatively influencing the sensory properties and starter culture activity of fermented products.

Application of microalgal-ZnO-NPs for reusing polyester/cotton blended fabric wastes after modification by cellulases enzymes

Polyester/cotton (PET/C) blended fabric wastes are produced daily in huge amounts, which constitutes an economic loss and an environmental threat if it is not reused appropriately. Modern textile waste recycling technologies put much effort into developing fabric materials with unique properties, such as bioactivity or new optical goods based on modern technologies, especially nano-biotechnology. In this study, zinc oxide nanoparticles (ZnO-NPs) were biosynthesized using the aqueous extract of Dunaliella sp. and immobilized on PET/C waste fabrics after enzymatically activated with cellulases. The produced Dunaliella-ZnO-NPs (10–20 nm with a spherical shape) were characterized by High-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Scanning electron microscopy-energy dispersive X-ray analyzer (SEM-EDAX), and some functional groups, such as CH, CO, NH, and CN (due to the presence of carboxyl, proteins and hydroxyl groups), were detected, revealing the biosynthesis of ZnO-NPs. The analysis showed that the resulting ZnO-NPS had potent antimicrobial effects, Ultraviolet (UV) protection capabilities, and no cytotoxic effects on the normal human fibroblast cell line (BJ1). On the other hand, enzymatic treatments of PET/C fabric waste with cellulases enhanced the immobilization of biosynthetic nanoparticles on their surface. Modified PET/C fabrics loaded with Dunaliella-ZnO-NPs showed antibacterial and UV protection capabilities making them an eco-friendly and cost-effective candidate for numerous applications. These applications can include the manufacture of active packaging devices, wastewater treatment units, and many other environmental applications.Graphical abstract

Color behavior of composite resin enhanced with different shapes of new antimicrobial polymer coated nanoparticles

BackgroundZein-coated magnesium oxide nanoparticles (zMgO NPs) demonstrate a potent antimicrobial effect, endorsing it as a compelling additive to dental materials formulations for oral health care advances. However, currently there is no data on the imprint of zMgO NPs on the color permanence of dental composites. The objective of this study is to evaluate the color stability of different types of composite enhanced with antimicrobial zein-coated magnesium oxide nanoparticles (zMgO NPs) of different shapes before and after thermocycling.MethodsTwo hundred composite samples were divided into four groups: Gp1: Tetric N-Flow with zMgO nanowires, Gp2: Tetric N-Flow with zMgO nanospheres, Gp3: Tetric N-Ceram with zMgO nanowires; Gp4: Tetric N-Ceram with zMgO nanospheres. Each group was subdivided into 5 subgroups (n = 10) with concentrations of zMgO NPs 0%, 0.3%, 0.5%, 1% and 2%. The characterization of the modified composite containing the zMgO was done via X-ray Diffraction, Field Emission Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR). Colorimetric evaluation was performed through spectrophotometry with a white background. Samples underwent color assessment using a spectrophotometer, followed by thermocycling, and then another color assessment.ResultsFESEM analysis showed a uniform distribution of the zMgO nanoparticles in the composite and FTIR illustrated no change in the spectra. However, the XRD spectra exhibited an amorphous pattern in the composite enhanced with zMgO NPs. There was no compelling discrepancy in color variation ΔE among the different groups before and after thermocycling (p > 0.05). A statistically notable variation in ΔL was found amid the control and N-Flow and N-Ceram with 2% zMgO nanospheres before and after thermocycling respectively (p < 0.05). While after thermocycling, there was a statistically significant difference in Δa in N-Flow and N-Ceram wires amid the control and the different groups (p < 0.05). Additionally, after thermocycling there was a statistically significant difference in Δb in N-Flow and N-Ceram wires between the control and the different groups (p < 0.05). The Tukey test exhibited no variation among the groups with different zMgO concentrations (p > 0.05).ConclusionEnhancing N-Flow and N-Ceram composite with antimicrobial zMgO nanowires and nanospheres did not alter the total color stability of the materials before and after thermocycling.

Recombinant production of human antimicrobial peptide LL- 37 and its secondary structure

AbstractAntimicrobial peptides, including the human cathelicidin LL-37, offer a possible solution to the global problem of bacterial resistance to antibiotics. LL-37 peptide has potent antimicrobial effects against current multi-drug resistant bacterial strains. The peptide itself is also characterized by a very diverse range of immunomodulatory effects. The aim of this study was to produce antimicrobially active peptide LL-37 in E. coli in high yields using an own expression system pUbEx100 with the fusion protein ubiquitin. The results showed that the peptide GLL-37 could be produced in high amounts, but this peptide did not have antimicrobial activity compared to synthetically produced LL-37. CD spectroscopy results showed that the produced peptide GLL-37 is in α-helix form in contrast to the sLL-37 (random-coil form). The recombinant peptide GLL-37 can not bind to the membrane in the α-helix form, it would have to be in the form of a random-coil. This study confirms by CD spectroscopy the previously observed mechanism of access of LL-37 peptide to the bacterial membrane obtained by NMR.

Histological study of the effect of curcumin on indomethacin-induced ileitis in adult male albino rats

Background Ileitis induced by indomethacin represents a well-standardized model in the study of acute and chronic inflammation of the intestine. Curcumin is an orange-yellow component of the herb turmeric. It has potent anti-inflammatory, antioxidant, antimicrobial, and anticancer effects. Aim This work was performed to show the effect of curcumin on indomethacin-induced ileitis in rats using H&amp;E stain. Materials and methods Thirty-six mature male albino rats (160–200 g) were used in this study. They were separated into four formain groups; control group: 8 rats, group I: 8 rats that received oral aqueous suspension of curcumin 100 mg/kg daily; group II: 10 rats included subgroups (IIA &amp; IIB): ileitis was induced by subcutaneous injection of two doses of indomethacin; each dose was 7.5 mg/kg separated by 24 hours, the rats were then killed on the 3rd and the 18th day, respectively, and group III: 10 rats included subgroups (IIIA&amp; IIIB): the ileitis group was treated with an oral aqueous suspension of curcumin 100 mg/kg daily and then the rats were killed on the 3rd and 18th day respectively. Results Subgroups IIA and IIB revealed sloughing of surface epithelium in the lumen of the intestine, ulceration, a significant decrease of villus height at H&amp;E sections, and inflammatory cellular infiltration. Subgroups IIIA and IIIB showed marked improvement in the pathological changes of induced ileitis. Conclusion Curcumin could decrease ileitis induced by indomethacin in rats. So, it could be useful for the treatment of intestinal injury.

Probiotic properties of Bacillus subtilis DG101 isolated from the traditional Japanese fermented food nattō.

Spore-forming probiotic bacteria offer interesting properties as they have an intrinsic high stability, and when consumed, they are able to survive the adverse conditions encountered during the transit thorough the host gastrointestinal (GI) tract. A traditional healthy food, nattō, exists in Japan consisting of soy fermented by the spore-forming bacterium Bacillus subtilis natto. The consumption of nattō is linked to many beneficial health effects, including the prevention of high blood pressure, osteoporosis, and cardiovascular-associated disease. We hypothesize that the bacterium B. subtilis natto plays a key role in the beneficial effects of nattō for humans. Here, we present the isolation of B. subtilis DG101 from nattō and its characterization as a novel spore-forming probiotic strain for human consumption. B. subtilis DG101 was non-hemolytic and showed high tolerance to lysozyme, low pH, bile salts, and a strong adherence ability to extracellular matrix proteins (i.e., fibronectin and collagen), demonstrating its potential application for competitive exclusion of pathogens. B. subtilis DG101 forms robust liquid and solid biofilms and expresses several extracellular enzymes with activity against food diet-associated macromolecules (i.e., proteins, lipids, and polysaccharides) that would be important to improve food diet digestion by the host. B. subtilis DG101 was able to grow in the presence of toxic metals (i.e., chromium, cadmium, and arsenic) and decreased their bioavailability, a feature that points to this probiotic as an interesting agent for bioremediation in cases of food and water poisoning with metals. In addition, B. subtilis DG101 was sensitive to antibiotics commonly used to treat infections in medical settings, and at the same time, it showed a potent antimicrobial effect against pathogenic bacteria and fungi. In mammalians (i.e., rats), B. subtilis DG101 colonized the GI tract, and improved the lipid and protein serum homeostasis of animals fed on the base of a normal- or a deficient-diet regime (dietary restriction). In the animal model for longevity studies, Caenorhabditis elegans, B. subtilis DG101 significantly increased the animal lifespan and prevented its age-related behavioral decay. Overall, these results demonstrate that B. subtilis DG101 is the key component of nattō with interesting probiotic properties to improve and protect human health.

A multi-functional double cross-linked chitosan hydrogel with tunable mechanical and antibacterial properties for skin wound dressing

Chitosan hydrogels with essential antibacterial properties and biocompatibility have great potential in tissue engineering and regeneration medicine. However, pure chitosan hydrogel could be limited by insufficient mechanical properties. In this work, we designed a multi-functional chitosan hydrogel based on the combination of chitosan methacrylate (CTSMA) and sulfhydrated chitosan (CTSSH), which is cross-linked simultaneously by free-radical polymerization reaction and Thiol-ene reaction. The CTSMA/CTSSH (CMS) hydrogels displayed superior tissue adhesive and mechanical properties when compared to pure CTSMA hydrogel. Additionally, the resulting hydrogels exhibited potent antimicrobial effects against both E. coli and S. aureus. Besides, the CMS hydrogels exhibited good biocompatibility as demonstrated by cytotoxicity and cell proliferation experiments using fibroblasts cells (L929) and adipose-derived stem cells (ADSCs). In vivo experiment, the repairing effect of hydrogels on full-thickness skin defect model in rats was studied. Histological and immunohistochemical staining results showed that CMS hydrogels promoted angiogenesis, dermal repair and epidermal regeneration. Overall, the study highlights the potential of the CMS hydrogels as a promising biomaterial in wound healing applications.

Iron oxide/silver hybrid nanoparticles impair the cholinergic system and cause reprotoxicity in Caenorhabditis elegans.

Iron oxide nanoparticles present superparamagnetic properties that enable their application in various areas, including drug delivery at specific locations in the organism. Silver nanoparticles have potent antimicrobial effects. Although the combination of Fe3O4-NPs and Ag-NPs in one hybrid nanostructure (Fe3O4@Ag-NPs) demonstrated promising targeted biomedical applications, their toxicological effects are unknown and need to be assessed. Caenorhabditis elegans is a promising model for nanotoxicological analysis, as it allows an initial screening of new substances. After exposure to Fe3O4-NPs, Ag-NPs and Fe3O4@Ag-NPs, we observed that hybrid NPs reduced the C. elegans survival and reproduction. Higher concentrations of Fe3O4@Ag-NPs caused an increase in cell apoptosis in the germline and a decrease in egg laying, which was associated with a decrease in worm swimming movements and abnormalities in the cholinergic neurons. Fe3O4@Ag-NPs caused an increase in reactive oxygen species, along with activation of DAF-16 transcription factor. A higher expression of the target genes GST-4::GFP and SOD-3::GFP were evidenced, which suggests the activation of the antioxidant system. Our results indicate the reprotoxicity caused by high levels of Fe3O4@Ag-NPs, as well as cholinergic neurotoxicity and activation of the antioxidant system in C. elegans, suggesting that high concentrations of these nanomaterials can be harmful to living organisms.

Potent antimicrobial effect induced by disruption of chloride homeostasis

Potent antimicrobial effect induced by disruption of chloride homeostasis

Exploring the Potent Anticancer, Antimicrobial, and Anti-Inflammatory Effects of Capparis Spinosa Oil Nanoemulgel

Natural remedies derived from plants have a long history of usage in the treatment of a wide variety of severe diseases. This study aims to develop a Capparis spinosa (C. spinosa) oil nanoemulgel and evaluate its antimicrobial, anticancer, and anti-inflammatory effects. C. spinosa oil was developed into a nanoemulsion using a self-nanoemulsifying method with Span 80 and Tween 80 as emulsifying agents. Carbopol hydrogel was mixed with the nanoemulsion to form nanoemulgel. After this, we tested the particle size, polydispersity index (PDI), rheology, antimicrobial, cytotoxic, and anti-inflammatory activities. The nanoemulsion formulation that has a PDI of 0.159 and a particle size of 119.87 nm is considered to be the optimum formulation. The C. spinosa oil nanoemulgel gave results similar to its nanoemulsion, where it had a PDI lower than 0.2, droplet size below 200 nm, and zeta potential less than −35. Also, it had a pseudoplastic rheological behavior. The C. spinosa oil nanoemulgel showed a significant effect on Methicillin-Resistant Staphylococcus Aureus (MRSA) and Klebsiella pneumoniae (K. pneumonia) (ATCC 13883) with zone inhibition diameters of 33 ± 1.9 mm and 30 ± 1.4 mm, respectively, as well as significant activities on the MCF-7, HepG2, and HeLa cancer cell lines with IC50 values of 194.98, 91.2, and 251.18 µg/mL, respectively, which were better than those of the original oil. Regarding its anti-inflammatory effect, C. spinosa oil had a positive impact on both COX-1 and COX-2 but was more selective for COX-1. Consequently, simple nanotechnology techniques provide a promising step forward in the development of pharmacological dosage forms.

Essential Oils of Distichochlamys benenica: Chemical Constituents, Mosquito Larvicidal and Antimicrobial Activities

In recent years, essential oils (EOs) have gained popularity for their potential as natural antimicrobial agents and mosquito larvae control. This study aimed to explore the chemical composition of EOs extracted from the leaves and rhizomes of Distichochlamys benenica Q.B. Nguyen &amp; Škorničk, and to evaluate their mosquito larvicidal and antimicrobial activities. The EOs were obtained using hydrodistillation and subjected to gas chromatography (GC) and GC-mass spectrometry to determine their chemical constituents. The main components identified in the leaf EO were β-pinene (47.7%), cis-β-elemene (8.5%), and α-pinene (7.8%), while the rhizome EO mainly consisted of geranyl acetate (25.7%), geranial (23.3%), neral (16.6%), and geraniol (8.4%). The mosquito larvicidal activity of the EOs was evaluated using larvae of Aedes aegypti and Culex quinquefasciatus during 24 and 48 h of treatment. The results demonstrated that these EOs effectively inhibited the mosquito larvae, with LC50 values ranging from 31.15 to 71.53 μg/mL and LC90 values ranging from 46.28 to 148.66 μg/mL. Additionally, the minimum inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50) values were used to evaluate the antimicrobial efficacy of EOs. Both EOs exhibited potent antimicrobial effects against Enterococcus faecalis ATCC 299212, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231, with MIC values ranging from 16 to 64 μg/mL and IC50 values ranging from 4.67 to 45.67 μg/mL. Overall, the mosquito larvicidal and antimicrobial activities of D. benenica EOs highlight their potential as natural alternatives for combating mosquito-borne diseases and microbial infections.