Cistus incanus: a natural source of antimicrobial metabolites.

The discovery of natural molecules with antimicrobial properties has become an urgent need for the global treatment of bacterium and virus infections. Cistus incanus, a Mediterranean shrub species, represents a valuable source of phytochemicals with an interesting wide-spectrum antimicrobial potential. In this study, we analysed the spectrum of molecules composing a commercial hydroalcoholic extract of C. incanus finding ellagitannins as the most abundant. The effect of the extract and its main constituents (gallic acid, ellagic acid and punicalin) was assessed as co-treatment during viral (HSV-1, HCoV-229E, SARS-CoV-2) and bacterial infection (Staphylococcus aureus and Escherichia coli) of cells and as pre-treatment before virus infections. The results indicated a remarkable antiviral activity of punicalin against SARS-CoV-2 by pre-treating both the viral and the host cells, and a major sensitivity of S. aureus to the C. incanus extract compared to E. coli. The present study highlights broad antimicrobial potential of C. incanus extract.

Orange-Red-Emitting Carbon Dots for Bilirubin Detection and Its Antibacterial Activity Against Escherichia coli and Staphylococcus aureus.

In this study, orange-red-emitting carbon dots (OR-CDs) were prepared from p-phenylenediamine (p-PDA) and urea as starting precursors through the hydrothermal method. The OR-CDs exhibited bright orange-red fluorescence at 618 nm when excited at 480 nm. The obtained OR-CDs exhibited stable photophysical properties under different physiological conditions. The unique photophysical property of OR-CDs were then utilized for fluorometric determination of bilirubin. The fluorometric assay revealed that the fluorescence intensity of OR-CDs is gradually quenched upon the addition of bilirubin (1-20 µM). The mechanism of fluorescence quenching was evaluated by steady-state fluorescence analysis and time-correlated single photon counting measurements. The OR-CDs showed good selectivity and sensitivity toward bilirubin over other common interfering biomolecules. The present fluorometric assay showed a linear response toward bilirubin between 1 and 10 µM with a limit of detection of 4.80 nM. Further, a fluorescence test cotton swab-based detection probe has been successfully developed by incorporating OR-CDs for the point-of-care detection of bilirubin in biofluids. Furthermore, a light-emitting diode light that emits orange-red light was prepared by embedding the OR-CDs within the poly(vinyl alcohol) polymer matrix. Moreover, the antibacterial activity of OR-CDs was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The antibacterial efficacy of OR-CDs was demonstrated by various mechanisms, such as reactive oxygen species generation, destruction of cell structure, chemical binding to membrane, and surface wrapping. Interestingly, the survival assay against L929 fibroblast cells exhibits favorable biocompatibility and bioimaging.

Novel Hydrogel Adjuvant of Chinese Medicine External Preparations for Accelerated Healing of Deep Soft Tissue Injuries.

Traditional Chinese medicine external prescriptions have displayed excellent clinical effects for treating deep soft tissue injuries. However, the effects cannot be fully utilized due to the limitations of their dosage forms and usage methods. It is still a challenge to develop a satisfactory adjuvant of traditional Chinese medicine external prescriptions. Herein, a hydrogel adjuvant was prepared based on gallic acid coupled ε-poly-l-lysine and partially oxidized hyaluronic acid. The resulting adjuvant shows great physicochemical properties, low hemolysis rate (still much less than 5% at 5 mg/mL), excellent antibacterial ability (about 95% at 2 mg/mL), strong antioxidant ability (1.687 ± 0.085 mmol FeSO4/(g hydrogel) at 1 mg/mL), as well as outstanding biocompatibility. A clinically used Chinese medicine external preparation was selected as an example to investigate the effectiveness of the adjuvant in treating deep soft tissue injuries. The results show that the prescription can be evenly dispersed in the adjuvant. Moreover, the introduction of the prescription has not significantly changed these advanced properties of the adjuvant. Importantly, the hydrogel adjuvant significantly improves the effectiveness of the prescription in treating deep soft tissue injuries. This work offers an alternative approach to the development of a new-type adjuvant of Chinese medicine external preparations and also provides a new strategy for the combination of traditional Chinese medicine and hydrogel to treat clinical diseases.

An Eco-friendly Approach to ZnO NP Synthesis Using Citrus reticulata Blanco Peel/Extract: Characterization and Antibacterial and Photocatalytic Activity.

Emission of greenhouse gases and infectious diseases caused by improper agro-waste disposal has gained significant attention in recent years. To overcome these hurdles, agro-waste can be valorized into valuable bioactive compounds that act as reducing or stabilizing agents in the synthesis of nanomaterials. Herein, we report a simple circular approach using Citrus reticulata Blanco (C. reticulata) waste (peel powder/aqueous extract) as green reducing and capping/stabilizing agents and Zn nitrate/acetate precursors to synthesize ZnO nanoparticles (NPs) with efficient antimicrobial and photocatalytic activities. The obtained NPs crystallized in a hexagonal wurtzite structure and differed clearly in their morphology. UV-vis analysis of the nanoparticles showed a characteristic broad absorption band between 330 and 414 nm belonging to ZnO NPs. Fourier transform infrared (FTIR) spectroscopy of ZnO NPs exhibited a Zn-O band close to 450 cm-1. The band gap values were in the range of 2.84-3.14 eV depending on the precursor and agent used. The crystallite size obtained from size-strain plots from measured XRD patterns was between 7 and 26 nm, with strain between 16 and 4%. The highly crystalline nature of obtained ZnO NPs was confirmed by clear ring diffraction patterns and d-spacing values of the observed lattice fringes. ZnNPeelMan_400 and ZnNExtrMan showed good stability, as the zeta potential was found to be around -20 mV, and reduced particle aggregation. Photoluminescence analysis revealed different defects belonging to oxygen vacancies (VO+ and VO+2) and zinc interstitial (Zni) sites. The presence of oxygen vacancies on the surface of ZnAcExtrMan_400 and ZnAcPeelMan_400 increased antimicrobial activity, specifically against Gram-negative bacteria Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis). ZnNExtrMan with a minimal inhibitory concentration of 0.156 mg/mL was more effective against Gram-positive bacteria Staphylococcus aureus (S. aureus), revealing a high influence of particle size and shape on antimicrobial activity. In addition, the photocatalytic activity of the ZnO NPs was examined by assessing the degradation of acid green dye in an aqueous solution under UV light irradiation. ZnAcPeelMan_400 exhibited excellent photocatalytic activity (94%) within 90 min after irradiation compared to other obtained ZnO NPs.

Production and characterization of polyvinyl alcohol films containing essential oil.

Packaging plays an important role in protecting foodstuffs against physicochemical damage and microbial activity, as well as extending shelf life. In recent years, petrochemical compounds that cause environmental pollution and contamination due to their non-biodegradability have been replaced by biocompatible polymer-based films in the food packaging industry. Due to aromatic essential oils (EO), various biological activities, and their potential to replace chemical preservatives in the field of food preservation, Star Anise essential oil, which has properties, such as free radical scavenger, antibacterial, antifungal and antiviral, was used as an additive in this study. Biodegradable and biocompatible polyvinyl alcohol (PVA) polymer was used as the matrix and polymer-based films were produced in 3 different concentrations. Spectral analysis, structural, chemical, and thermal characterizations, and surface morphologies of the produced films by the direct incorporation method were examined. In addition, the antibacterial activities of the films on Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 25922, and Acinetobacter baumannii ATCC BAA 747 bacteria were investigated. As a result of the examinations, it was determined that an interfacial interaction occurred between the matrix and the filler, and the produced films were thermally resistant and showed antibacterial activity against Gram (+)/Gram (-) bacteria. Consequently, it can be concluded that PVA films containing Star Anise essential oil present a prospective substitute in a variety of industrial packaging systems, including those for food, medicine, and cosmetics.

Engineering resveratrol-loaded chitosan nanoparticles for potential use against Helicobacter pylori infection.

Helicobacter pylori (H. pylori) is a microorganism directly linked to severe clinical conditions affecting the stomach. The virulence factors and its ability to form biofilms increase resistance to conventional antibiotics, growing the need for new substances and strategies for the treatment of H. pylori infection. The trans-resveratrol (RESV), a bioactive polyphenol from natural sources, has a potential activity against this gastric pathogen. Here, Chitosan nanoparticles (NP) containing RESV (RESV-NP) were developed for H. pylori management. The RESV-NP were prepared using the ionic gelation method and characterized by Dynamic Light Scattering (DLS), Nanoparticle Tracking Analysis (NTA), and, Cryogenic Transmission Electron Microscopy (Cryo - TEM). The encapsulation efficiency (EE) and in vitro release rate of RESV were quantified using high-performance liquid chromatography. RESV-NP performance against H. pylori was evaluated by the quantification of the minimum inhibitory/bactericidal concentrations (MIC/MBC), time to kill, alterations in H. pylori morphology in its planktonic form, effects against H. pylori biofilm and in an in vitro infection model. RESV-NP cytotoxicity was evaluated against AGS and MKN-74 cell lines and by hemolysis assay. Acute toxicity was tested using Galleria mellonella model assays. RESV-NP showed a spherical shape, size of 145.3 ±â€¯24.7 nm, polydispersity index (PDI) of 0.28 ±â€¯0.008, and zeta potential (ZP) of + 16.9 ±â€¯1.81 mV in DLS, while particle concentration was 3.12 x 1011 NP/mL (NTA). RESV-NP EE was 72 %, with full release within the first 5 min. In microbiological assays, RESV-NP presented a MIC/MBC of 3.9 µg/mL, a time-kill of 24 h for complete eradication of H. pylori. At a concentration of 2xMIC (7.8 µg/mL), RESV-NP completely eradicated the H. pylori biofilm, and in an in vitro infection model, RESV-NP (4xMIC - 15.6 µg/mL) showed a significant decrease in bacterial load (1 Log10CFU/mL) when compared to the H. pylori J99 control. In addition, they did not demonstrate a toxic character at MIC concentration for both cell lines. The use of the RESV-NP with mucoadhesion profile is an interesting strategy for oral administration of substances targeting gastric disorders, linked to H. pylori infections.

Physicochemical properties as a function of lomefloxacin biological activity.

OBJECTIVE: Aim: The goal is to discover QSAR of Lomefloxacin as antibacterial activity. PATIENTS AND METHODS: Materials and Methods: A number of lomefloxacins analogs activities were studied by program Windows Chem SW. The analogues were obtained and energy minimization was carried out through Molecular Modeling Program, the calculations were performed using General Atomic and Molecular Electronic Structure System (GAMESS) software. RESULTS: Results: There were six descriptions (N-quinoline more (-) ev charge, Kinetic Energy, Potential Energy, Log p, Log S, F6 charge) results have highly compatible of physicochemical properties with lomefloxacin analogs activities. It can be used to estimate the activities depending on QSAR equation of lomefloxacin analogs. CONCLUSION: Conclusions: The parameters used for calculation were depending on the quantum chemical was employed in deriving from computational study of properties and can used to predict the activities of certain analogs of Lomefloxacins as antibacterial compounds.

Phytochemical profile, in vitro antioxidant and antibacterial activities of different extracts of an Algerian endemic: Teucrium atratum.

Teucrium atratum Pomel. is a species belonging to the Lamiaceae family used in Algerian folk medicine. The present work essentially aimed to assess the phenolic composition and to evaluate some of the biological effects of different extracts, never previously studied, of T. atratum growing in Algeria. High levels of total phenolic and flavonoids were recorded in the hydromethanolic extract. Chlorogenic acid, isoquercetin, coumarin, cinnamic acid, quercetin dihydrate, and catechin were identified in the methanolic extract by mean of HPLC. The antioxidant activity assessed showed that the methanolic extract was the most active, while, the hydromethanolic extract showed a great power to reduce iron. In addition, all extracts had a significant antibacterial effect against the four tested bacterial strains, with Staphylococcus aureus as the most sensitive one. These findings can be a starting point to evaluate the plant as a source of natural bioactive compounds with antioxidant and antibacterial effects.

Gold Nanoparticle-Based Drug Delivery System for the Diagnosis and Treatment of Bacterial Meningitis.

Managing bacterial pathogens in the central nervous system is an immense issue for researchers all around the globe. The problem of these infections remains throughout the population, regardless of the discovery of several possible medicines. The major obstacle to drug delivery is the BBB, but only a few medicines that fulfill demanding requirements can penetrate it. Considering inadequate antibiotic alternatives and the increasing development of resistance, it is more important than ever to find new approaches to address this worldwide problem. Medical nanotechnology has evolved as a cutting-edge and effective means of treating many of the most difficult CNS illnesses, including bacterial meningitis. Various metallic nanoparticles, such as gold, silver, and titanium oxide, have shown bactericidal potential. Gold nanoparticles have gotten a great deal of interest due to their excellent biocompatibility, simplicity of surface modification, and optical qualities. The current study described AuNP-based detection and therapy options against meningitis-- causing bacteria, including bacterial pathogens' mechanisms for crossing BBB and AuNPs' mode of Action against those bacteria. The current study looked into green synthesized bactericidal gold nanoparticles-based therapy techniques for diagnosing and intervening in bacterial meningitis. Nevertheless, more research is needed before these laboratory findings can be translated into therapeutic trials. Nonetheless, we can confidently assert that the knowledge acquired and addressed in this study will benefit neuro-nanotechnology researchers.

The neutralizing effect of heparin on blood-derived antimicrobial compounds: impact on antibacterial activity and inflammatory response.

Acting through a combination of direct and indirect pathogen clearance mechanisms, blood-derived antimicrobial compounds (AMCs) play a pivotal role in innate immunity, safeguarding the host against invading microorganisms. Besides their antimicrobial activity, some AMCs can neutralize endotoxins, preventing their interaction with immune cells and avoiding an excessive inflammatory response. In this study, we aimed to investigate the influence of unfractionated heparin, a polyanionic drug clinically used as anticoagulant, on the endotoxin-neutralizing and antibacterial activity of blood-derived AMCs. Serum samples from healthy donors were pre-incubated with increasing concentrations of heparin for different time periods and tested against pathogenic bacteria (Acinetobacter baumannii, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus) and endotoxins from E. coli, K. pneumoniae, and P. aeruginosa. Heparin dose-dependently decreased the activity of blood-derived AMCs. Consequently, pre-incubation with heparin led to increased activity of LPS and higher values of the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Accordingly, higher concentrations of A. baumannii, E. coli, K. pneumoniae, and P. aeruginosa were observed as well. These findings underscore the neutralizing effect of unfractionated heparin on blood-derived AMCs in vitro and may lead to alternative affinity techniques for isolating and characterizing novel AMCs with the potential for clinical translation.

Bacterial cellulose-based hydrogel with regulated rehydration and enhanced antibacterial activity for wound healing.

Bacterial cellulose (BC) hydrogels are promising medical biomaterials that have been widely used for tissue repair, wound healing and cartilage engineering. However, the high water content of BC hydrogels increases the difficulty of storage and transportation. Moreover, they will lose their original hydrogel structure after dehydration, which severely limits their practical applications. Introducing the bio-based polyelectrolytes is expected to solve this problem. Here, we modified BC and combined it with quaternized chitosan (QCS) via a chemical reaction to obtain a dehydrated dialdehyde bacterial cellulose/quaternized chitosan (DBC/QCS) hydrogel with repeated swelling behavior and good antibacterial properties. The hydrogel can recover the initial state on the macro scale with a swelling ratio over 1000 % and possesses excellent antimicrobial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with a killing rate of 80.8 % and 81.3 %, respectively. In addition, the hydrogel has excellent biocompatibility, which is conducive to the stretching of L929 cells. After 14 d of in vivo wound modeling in rats, it was found that the hydrogel loaded with pirfenidone (PFD) could promote collagen deposition and accelerate wound healing with scar prevention. This rehydratable hydrogel can be stored and transported under dry conditions, which is promising for practical applications.

Beyond the ß-amino alcohols framework: identification of novel ß-hydroxy pyridinium salt-decorated pterostilbene derivatives as bacterial virulence factor inhibitors.

BACKGROUND: Bacterial virulence factors are involved in various biological processes and mediate persistent bacterial infections. Focusing on virulence factors of phytopathogenic bacteria is an attractive strategy and crucial direction in pesticide discovery to prevent invasive and persistent bacterial infection. Hence, discovery and development of novel agrochemicals with high activity, low-risk, and potent anti-virulence is urgently needed to control plant bacterial diseases. RESULTS: A series of novel ß-hydroxy pyridinium cation decorated pterostilbene derivatives were prepared and their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) were systematacially assessed. Among these pterostilbene derivatives, compound 4S exhibited the best antibacterial activity against Xoo in vitro, with an half maximal effective concentration (EC50) value of 0.28 µg mL-1. A series of biochemical assays including scanning electron microscopy, crystal violet staining, and analysis of biofilm formation, swimming motility, and related virulence factor gene expression levels demonstrated that compound 4S could function as a new anti-virulence factor inhibitor by interfering with the bacterial infection process. Furthermore, the pot experiments provided convinced evidence that compound 4S had the high control efficacy (curative activity: 71.4%, protective activity: 72.6%), and could be used to effectively manage rice bacterial leaf blight in vivo. CONCLUSION: Compounds 4S is an attractive virulence factor inhibitor with potential for application in treating plant bacterial diseases by suppressing production of several virulence factors. © 2024 Society of Chemical Industry.

Rakicidin J and K, two cytotoxic and antibacterial cyclic depsipeptides from the marine bacterium Micromonospora chalcea.

Rakicidin J (1) and rakicidin K (2), two new cyclic depsipeptides, were isolated from culture broth of Micromonospora chalcea FIM-R150103. Their structures were elucidated by extensive analysis of NMR, HR-ESI-MS, and electronic circular dichroism (ECD) data. The two compounds showed strong cytotoxic activity against human colon carcinoma HCT-8 and human pancreatic cancer PANC-1 cells under normoxic and hypoxic conditions in the range of IC50 values from 0.024 to 0.79 µg/mL. Moreover, compounds 1 and 2 also showed moderate antibacterial activity against ten Gram-positive bacterial strains with MIC values ranging from 4 to more than 32 µg/mL. Structure-activity relationship of these two compounds with a close analogue, rakicidin B1, is also discussed.

Efflux pump effects on levofloxacin resistance in Mycobacterium abscessus.

Mycobacterium abscessus (M. abscessus) inherently displays resistance to most antibiotics, with the underlying drug resistance mechanisms remaining largely unexplored. Efflux pump is believed to play an important role in mediating drug resistance. The current study examined the potential of efflux pump inhibitors to reverse levofloxacin (LFX) resistance in M. abscessus. The reference strain of M. abscessus (ATCC19977) and 60 clinical isolates, including 41 M. abscessus subsp. abscessus and 19 M. abscessus subsp. massilense, were investigated. The drug sensitivity of M. abscessus against LFX alone or in conjunction with efflux pump inhibitors, including verapamil (VP), reserpine (RSP), carbonyl cyanide 3-chlorophenylhydrazone (CCCP), or dicyclohexylcarbodiimide (DCC), were determined by AlarmarBlue microplate assay. Drug-resistant regions of the gyrA and gyrB genes from the drug-resistant strains were sequenced. The transcription level of the efflux pump genes was monitored using qRT-PCR. All the tested strains were resistant to LFX. The drug-resistant regions from the gyrA and gyrB genes showed no mutation associated with LFX resistance. CCCP, DCC, VP, and RSP increased the susceptibility of 93.3% (56/60), 91.7% (55/60), 85% (51/60), and 83.3% (50/60) isolates to LFX by 2 to 32-fold, respectively. Elevated transcription of seven efflux pump genes was observed in isolates with a high reduction in LFX MIC values in the presence of efflux pump inhibitors. Efflux pump inhibitors can improve the antibacterial activity of LFX against M. abscessus in vitro. The overexpression of efflux-related genes in LFX-resistant isolates suggests that efflux pumps are associated with the development of LFX resistance in M. abscessus.

Psidium guajava-mediated green synthesis of Fe-doped ZnO and Co-doped ZnO nanoparticles: a comprehensive study on characterization and biological applications.

The efficacy of nanoparticles (NPs) in healthcare applications hinges on their biocidal activity and biocompatibility. This research is dedicated to green-synthesized NPs with potent biocidal properties, aiming for high inhibition rates in bacterial infections and offering a multifunctional application, including potential use in anticancer therapy, in comparison to traditional antibiotics. The present study focuses on synthesis of zinc oxide (ZnO) nanoparticles (NPs), including iron-doped ZnO (GZF) and cobalt-doped ZnO (GZC), using the green co-precipitation method involving Psidium guajava (P. guajava) leaf extract. The physicochemical properties of the synthesized NPs were analyzed using various characterization techniques. The antibacterial and anticancer activity depends on the generation of reactive oxygen species (ROS), particle size, surface area, oxygen vacancy, Zn2+ release, and diffusion ability. The antibacterial activity of the synthesized NPs was tested against various Gram-positive (Streptococcus pneumoniae (S. pneumoniae), Bacillus subtilis (B. subtilis) and Gram-negative (Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) bacterial strains. The zone of inhibition showed higher activity of GZC (18-20 mm) compared to GZF (16-19 mm) and GZO (11-15 mm) NPs. Moreover, anticancer studies against blood cancer cell line (MOLT-4) showed half-maximal inhibitory concentration of 11.3 µg/mL for GZC compared to GZF and GZO NPs with 12.1 µg/mL and 12.5 µg/mL, respectively. Cytotoxicity assessments carried out on the fibroblast L929 cell line indicated that GZO, GZF, and GZC NPs demonstrated cell viabilities of 85.43%, 86.66%, and 88.14%, respectively. Thus, green-synthesized GZC NPs hold promise as multifunctional agents in the biomedical sector.

Antibacterial activity of lysozyme after association with carboxymethyl konjac glucomannan.

The unique high isoelectric point of lysozyme (LYZ) restricts its application in composite antibacterial coating due to the unfavorable liability to electrostatic interaction with other components. In this work, the antibacterial activity of a dispersible LYZ-carboxymethyl konjac glucomannan (CMKGM) polyelectrolyte complex was evaluated. Kinetic analysis revealed that, compared with free LYZ, the complexed enzyme exhibited decreased affinity (Km) but markedly increased Vmax against Micrococcus lysodeikticus, and QCM and dynamic light scattering analysis confirmed that the complex could bind with the substrate but in a much lower ratio. The complexation with CMKGM did not alter the antibacterial spectrum of LYZ, and the complex exerted antibacterial function by delaying the logarithmic growth phase and impairing the cell integrity of Staphylococcus aureus. Since the LYZ-CMKGM complex is dispersible in water and could be assembled easily, it has great potential as an edible coating in food preservation.

Antibacterial activity of a short de novo designed peptide against fish bacterial pathogens.

In the face of increasing antimicrobial resistance in aquaculture, researchers are exploring novel substitutes to customary antibiotics. One potential solution is the use of antimicrobial peptides (AMPs). We aimed to design and evaluate a novel, short, and compositionally simple AMP with potent activity against various bacterial pathogens in aquaculture. The resulting peptide, KK12YW, has an amphipathic nature and net charge of + 7. Molecular docking experiments disclosed that KK12YW has a strong affinity for aerolysin, a virulence protein produced by the bacterial pathogen Aeromonas sobria. KK12YW was synthesized using Fmoc chemistry and tested against a range of bacterial pathogens, including A. sobria, A. salmonicida, A. hydrophila, Edwardsiella tarda, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and methicillin-resistant S. aureus. The AMP showed promising antibacterial activity, with MIC and MBC values ranging from 0.89 to 917.1 µgmL-1 and 3.67 to 1100.52 µgmL-1, respectively. In addition, KK12YW exhibited resistance to high temperatures and remained effective even in the presence of serum and salt, indicating its stability. The peptide also demonstrated minimal hemolysis toward fish RBCs, even at higher concentrations. Taken together, these findings indicate that KK12YW could be a highly promising and viable substitute for conventional antibiotics to combat microbial infections in aquaculture.

Long-Lasting Silver Nanoparticles Synthesized with Tagetes erecta and Their Antibacterial Activity against Erwinia amylovora, a Serious Rosaceous Pathogen.

A rapid, eco-friendly, and simple method for the synthesis of long-lasting (2 years) silver nanoparticles (AgNPs) is reported using aqueous leaf and petal extracts of Tagetes erecta L. The particles were characterized using UV-Visible spectrophotometry and the analytical and crystallographic techniques of transmission electron microscopy (TEM). The longevity of the AgNPs was studied using UV-Vis and high-resolution TEM. The antibacterial activity of the particles against Erwinia amylovora was evaluated using the Kirby-Bauer disk diffusion method. The results were analyzed using ANOVA and Tukey's test (p ≤ 0.05). Both the leaf and petal extracts produced AgNPs, but the leaf extract (1 mL) was long-lasting and quasi-spherical (17.64 ± 8.87 nm), with an absorbance of UV-Vis λmax 433 and a crystalline structure (fcc, 111). Phenols, flavonoids, tannins, and terpenoids which are associated with -OH, C=O, and C=C were identified in the extracts and could act as reducing and stabilizing agents. The best antibacterial activity was obtained with a nanoparticle concentration of 50 mg AgNPs L-1. The main contribution of the present research is to present a sustainable method for producing nanoparticles which are stable for 2 years and with antibacterial activity against E. amylovora, one of most threatening pathogens to pear and apple productions.

Antibacterial and Anti-Inflammatory Polysaccharide from Fructus Ligustri Lucidi Incorporated in PVA/Pectin Hydrogels Accelerate Wound Healing.

In cutaneous wound healing, an overproduction of inflammatory chemokines and bacterial infections impedes the process. Hydrogels can maintain a physiologically moist microenvironment, absorb chemokines, prevent bacterial infection, inhibit bacterial reproduction, and facilitate wound healing at a wound site. The development of hydrogels provides a novel treatment strategy for the entire wound repair process. Here, a series of Fructus Ligustri Lucidi polysaccharide extracts loaded with polyvinyl alcohol (PVA) and pectin hydrogels were successfully fabricated through the freeze-thaw method. A hydrogel containing a 1% mixing weight ratio of FLL-E (named PVA-P-FLL-E1) demonstrated excellent physicochemical properties such as swellability, water retention, degradability, porosity, 00drug release, transparency, and adhesive strength. Notably, this hydrogel exhibited minimal cytotoxicity. Moreover, the crosslinked hydrogel, PVA-P-FLL-E1, displayed multifunctional attributes, including significant antibacterial properties, earlier re-epithelialization, production of few inflammatory cells, the formation of collagen fibers, deposition of collagen I, and faster remodeling of the ECM. Consequently, the PVA-P-FLL-E1 hydrogel stands out as a promising wound dressing due to its superior formulation and enhanced healing effects in wound care.

New Thiosemicarbazide Derivatives with Multidirectional Biological Action.

Over the years, several new medicinal substances have been introduced for the treatment of diseases caused by bacteria and parasites. Unfortunately, due to the production of numerous defense mechanisms by microorganisms and parasites, they still pose a serious threat to humanity around the world. Therefore, laboratories all over the world are still working on finding new, effective methods of pharmacotherapy. This research work aimed to synthesize new compounds derived from 3-trifluoromethylbenzoic acid hydrazide and to determine their biological activity. The first stage of the research was to obtain seven new compounds, including six linear compounds and one derivative of 1,2,4-triazole. The PASS software was used to estimate the potential probabilities of biological activity of the newly obtained derivatives. Next, studies were carried out to determine the nematocidal potential of the compounds with the use of nematodes of the genus Rhabditis sp. and antibacterial activity using the ACCT standard strains. To determine the lack of cytotoxicity, tests were performed on two cell lines. Additionally, an antioxidant activity test was performed due to the importance of scavenging free radicals in infections with pathogenic microorganisms. The conducted research proved the anthelmintic and antibacterial potential of the newly obtained compounds. The most effective were two compounds with a 3-chlorophenyl substituent, both linear and cyclic derivatives. They demonstrated higher efficacy than the drugs used in treatment.