Antibacterial Properties Research Articles

Green synthesis of multifunctional natural rubber-lignin nanocomposites: A sustainable approach for waste reduction

Lignin, a valuable biomaterial having an array of exciting properties is increasingly favoured as a reinforcement material in the fabrication of green composites. Reinforcement in biopolymers like natural rubber (NR) using lignin nanoparticles (LNP) is considered a hotspot today. In this study, LNP synthesized via the homogenization method was incorporated into natural rubber latex (NRL) using probe sonication, and NR/Lignin nanocomposites (NR/LNP) were fabricated using latex dipping method. The addition of LNP resulted in significant enhancements in mechanical and antibacterial properties, biodegradability, and ultraviolet (UV) blocking capabilities with the addition of 7 parts per hundred rubber (phr) of LNP, due to the uniform dispersion and effective interaction between NR and LNP. This research demonstrates a versatile pathway for integrating LNP into NR through a green method, enabling the production of eco-friendly NR nanocomposites for multifunctional applications. This pathway contributes to a safe disposal of NR based products.

Zirconium-Doped Zinc Nanocomposites (ZDZN): Preparation, Characterization, and Evaluation of Antibacterial Activity

The present study focuses on zirconium-doped zinc nanocomposites (ZDZN), representing a novel class of materials with antibacterial and antifungal properties. This work involves the preparation, characterization, and evaluation of the antibacterial activity of ZDZN. Zinc oxide nanoparticles were doped with varying concentrations of zirconium ions to create nanocomposites using a simple precipitation technique. The structural, morphological, and chemical properties were investigated using EDS, TEM, SEM, and XRD analyses. The results indicated the successful incorporation of zirconium ions into the lattice of zinc oxide nanoparticles, resulting in nanocomposites with well-defined shapes and compositions. Agar diffusion studies were conducted to assess the antibacterial activities of the nanocomposites against various bacterial and fungal species. The findings revealed that ZDZN exhibited superior antibacterial activity compared to pure zinc oxide nanoparticles, attributed to the concentration-dependent effect of the zirconium dopant. Furthermore, the nanocomposites demonstrated excellent biocompatibility and stability, making them highly suitable for applications in biomedical devices and antimicrobial coatings.

Photo-crosslinked hyaluronic acid hydrogels designed for simultaneous delivery of mesenchymal stem cells and tannic acid: Advancing towards scarless wound healing

The quest for scarless wound healing is imperative in healthcare, aiming to diminish the challenges of conventional wound treatment. Hyaluronic acid (HA), a key component of the skin's extracellular matrix, plays a pivotal role in wound healing and skin rejuvenation. Leveraging the advantages of HA hydrogels, this research focuses first on tuning the physicochemical and mechanical properties of photo-crosslinkable methacrylated HA (MAHA) by varying the methacrylation degree, polymer concentration, photo-crosslinker concentration, and UV exposure time. The optimized hydrogel, featuring suitable porosity, swelling ratio, degradability, and mechanical properties, was then used for the combined delivery of tannic acid (TA), known for its hemostatic, antibacterial, and antioxidant properties, and Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) cultured on the MAHA-TA hydrogel to enhance skin regeneration. The composite MAHA-TA-MSC hydrogel demonstrated favorable pores and biocompatibility, evidenced by cell viability, and promoted cell proliferation. When applied to dorsal wounds in rats, this composite hydrogel accelerated wound healing and reduced scarring. Additionally, molecular and histopathological analyses revealed increased expression of IL-10, the TGF-β3/TGF-β1 ratio, and the Collagen III/Collagen I ratio. These findings suggest that the MAHA-TA-MSC hydrogel is a promising candidate for scarless acute wound healing.

Deciphering the effect of Potentilla fulgens root extract against healthy HUVEC cell line and cancer cell lines (A549 and SKOV-3)

BackgroundPotentilla fulgens, a highly valued indigenous medicinal herb grown in high altitudes of the Himalayan region with anticancer, hypoglycaemic, antibacterial, anti-inflammatory, and antiulcerogenic properties, are used in traditional systems of medicine. This study was aimed to investigate the effect of P. fulgens root extract, as one of the natural alternatives to chemotherapeutic drugs used in cancer treatment, on proliferation, apoptosis, and autophagy of human non-small cell lung cancer cell line (A549), human ovarian cancer cell line (SKOV-3), and healthy human umbilical vein endothelial cell line (HUVEC). MethodsAnti-proliferative effect was assessed by MTT assay. The expression of autophagy and apoptosis-related proteins was evaluated by western blotting. Total oxidant status (TOS) and total antioxidant capacity (TAC) test were determined using standard kit methods. ResultsOur results showed that the extract inhibited proliferation of HUVEC, A549, and SKOV-3 cells in a dose-dependent manner. MTT assay analysis revealed that the extract significantly (P<0.05) induced mortality in HUVEC, A549, and SKOV-3 cells. Western blot results revealed increased expression of NF-κB after the extract treatment but led to the down-regulation in Beclin-1, Bax, extracellular-signal-related kinase 1 and 2, Sequestosome-1, and Cleaved Casp-3 levels. Treatment groups showed an increase in TOS and TAC values in A549 and SKOV-3 cell lines, while HUVEC cell line showed an increase in TAC and a decrease in TOS values, compared to the control group. ConclusionsOur findings indicated that P. fulgens root extract inhibited the proliferation of healthy cells and cancer cells through cell cycle arrest, representing its limited application as therapeutic agent in cancer treatment.

Antibiofilm and antivirulence efficacy of Pleurotus platypus methanolic extract against Staphylococcus aureus through ROS generation and cell membrane disruption

Multi-drug resistance is recognized as a significant worldwide public health concern in the current century. Biofilm formation further exacerbates bacterial resistance to antibacterial medications, host immunological responses, and phagocytosis, resulting in long-lasting chronic illnesses. Investigating natural resources is a very potent approach for developing alternative anti-infective medications to effectively control multi-drug resistant bacterial infections. In this study, a unique mushroom species namely Pleurotus platypus had been discovered from the Terai-Duars region of West Bengal, India. The myco-chemical profiling and preliminary chemical analysis of Pleurotus platypus methanolic extract determined the significant presence of metabolites belonging to several major chemical classes such as flavonoid, alkaloid, triterpenoid, polyphenol, benzoic acids, coumarin, flavone etc. Most intriguingly, the extract possessed effective antibacterial, antibiofilm and antivirulence properties against Staphylococcus aureus and Methicillin resistant Staphylococcus aureus, one of the most notable drug-resistant opportunistic and nosocomial pathogens. Mechanistically, the mushroom extract enhanced the production of Reactive Oxygen Species (ROS) inside the targeted bacteria, causing alterations in membrane potential, damage to the cellular membrane and further release of intracellular DNA, destined to cell death. Moreover, the methanolic extract reported the eradication of pre-existing biofilms from the urinary catheter surface, hinting towards its future application in the related field. To summarize, Pleurotus platypus methanolic extract could be an excellent alternative antibacterial and antibiofilm therapeutic candidate for the effective management of Staphylococcus infections with improved outcome.

Biological characterization of marine algae and its potent in vitro antioxidant, antimicrobial and larvicidal activity: a focus on Ulva lactuca Linnaeus 1753: 1163.

This study evaluated the biological characteristics of seaweeds Turbinaria ornata, Ulva lactuca, and Gracilaria crassa. Among the seaweeds tested, ethyl acetate extract of Ulva lactuca exhibited the highest antibacterialactivity against Salmonella enterica, Staphylococcus aureus, and Pseudomonas aeruginosa. The phytochemical analysis of ULME and ULEA showed the presence of most of the tested phytochemicals, whereas only amino acids, tannins, glycosides, and carbohydrates were detected by ULHE. The DPPH scavenging property of U. lactuca exerted the maximum antioxidant property of 62.54% (ULME), 75.64% (ULEA), and 39.55% (ULHE), whereas the alpha amylase inhibitory property (µg/mL) of ULME, ULEA, and ULHE was, respectively, 80.99, 51.15, and 49.23. ULME, ULEA, and ULHE exhibited the greatest alpha-glucosidase inhibition, with IC50 values (g/mL) of 116.12, 45.59, and 170.10 correspondingly. ULEA also showed potent mosquito-larvicidal effects against Aedes aegypti larvae with the maximum lethal concentration values with LC50 and LC90 values (mg/mL) being 11.55 and 65.97, respectively. FTIR analysis of ULME, ULHE, and ULEA were found to have various functional groups, including alkanes, carboxylic acids, alkenes, alkynes, aldehydes, amides and alkanes, ketones, and aromatics, while HPLC revealed a strong peak at 4.760 retention time. In conclusion, Ulva lactuca, particularly its ethyl acetate extract, demonstrates significant antibacterial, antioxidant, and enzyme-inhibitory properties, highlighting its therapeutic and biotechnological potential. Its diverse phytochemicals and effective mosquito-larvicidal activity further support its broad application prospects.

Platelet antiaggregant activity of Hypericum perforatum extracts

BackgroundIn addition to its potential use as an antidepressant, different studies have shown that Hypericum perforatum (HP) can have antibacterial, antioxidant, and antiviral properties. Despite this potential, most of the therapeutic bioactivities attributed to HP need further scientific support. In a previous study we found an inhibitory effect of HP in platelet activation markers. So, in the present work we investigate the effect of HP in another aspect of platelet function, platelet aggregation. MethodsFirst, the effect of different concentrations of the total alcoholic extract of HP on platelet aggregation was studied in 9 healthy donors by aggregometry methods using collagen as agonist. After that, to obtain dose-effect curves, 3 experiments were carried out independently in a single individual using collagen, adenosine diphosphate and epinephrine as agonists. ResultsOur results reveal a marked inter-individual variability and a significant dose-dependent decrease of aggregation responses induced by collagen in the presence of HP extracts (mean of minimum inhibition: 8% at a dose of 0.068 mg es/ml and mean of maximum inhibition: 43% at a dose of 0.456 mg es/ml). With the results obtained it was possible to obtained a IC50 value of 0.34 mg es/ml. ConclusionsWe can conclude that HP has a dose-dependent inhibitory effect on platelet function (activation and aggregation responses), therefore, our results suggest that HP may be recognized as an herbal medicine with anti-platelet properties.

Network-Pharmacology-Based Study on Active Phytochemicals and Molecular Mechanism of Cnidii Fructus in Treating Colorectal Cancer.

Cnidii Fructus (CF) is known for its antibacterial, anti-inflammatory, and antitumor properties, as well as its activities against kidney deficiency and impotence. In this study, we aimed to explore the anti-CRC cancer effect and molecular mechanism of CF via network pharmacology and in vitro antitumor experiments. Network pharmacology was used to investigate the anti-CRC mechanism of CF. First, a series of databases was used to screen the active phytochemical targets and anti-CRC core targets. Then, the GO and KEGG pathways were analyzed to predict possible mechanisms. Molecular docking analysis explore core targets-phytochemicals interactions. In vitro antitumor experiments were carried on verifying anti-CRC mechanism of CF. In this study, 20 active ingredient targets and 50 intersecting targets were analyzed by Cytoscape software 3.9.1 to obtain the core genes and phytochemicals. Then, the GO and KEGG pathways of 50 intersecting targets were analyzed to predict possible mechanisms. The results from GO and KEGG indicated that CF has significant antitumor efficacy, which involves many signaling pathways, such as PI3K/AKT and p53. The five core targets and five core phytochemicals were screened for molecular docking to show protein-ligand interactions. According to the results of molecular docking, the compound O-acetylcolumbianetin was selected for the anti- CRC functional verification in vitro. MTT assay showed that O-acetylcolumbianetin significantly inhibited the proliferation of colorectal HCT116 cells in a time- and quantity-dependent manner. O-acetylcolumbianetin can promote the expression of CASP3 protein, induce HCT116 cells apoptosis, thus exert anti-CRC effect. This study preliminarily verified the anti-CRC effect and molecular mechanism of CF and provided a reference for Traditional Chinese Medicine anti-tumor subsequent research.

Chitosan-grafted Cyclodextrin via Click Chemistry as an Encapsulating Agent to Enhance the Antibacterial Activity of Thymol

Introduction: This paper aimed to investigate, for the first time, the possibility of increasing the antibacterial activities of thymol (TH) by developing an encapsulating agent based on chitosan-grafted cyclodextrin. For this purpose, β-cyclodextrin was monosubstituted at position 6 via propargyl bromide, and chitosan’s amine groups were converted to azide functions. After alkylation and diazotization reactions, the grafting of β-cyclodextrin onto the chitosan (CSβCD) was realized via click chemistry alkyne–azide cycloaddition. Methods: The incorporation of TH into chitosan-grafted β-cyclodextrin (TH/CS-βCD) was performed by the freeze-drying method, and the encapsulation efficiency was investigated based on various mass ratios (TH:CS-βCD). The optimized inclusion complex was then thoroughly examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Results: The antibacterial activity was assessed against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis using broth-microdilution assay. Fourier transform infrared spectroscopy analysis demonstrated the successful grafting of β-cyclodextrin onto chitosan since the optimum mass ratio between TH and CS-βCD was 1:8 (w:w), corresponding to 78 ± 3.42% of encapsulation efficiency, while SEM, XRD, TGA and DSC confirmed the establishment of TH/CS-βCD inclusion complexes. Conclusion: The in vitro investigation showed that TH/CS-βCD exhibited higher antibacterial properties compared to TH in free form.

Interfacial engineering of 0D–2D hierarchical MXene@PEI@AgNC nanohybrids to achieve flame retardant, mechanical and antibacterial properties of ABS nanocomposites

It is an intractable challenge that the hierarchical MXene-based nanohybrid fillers are intended to modify the inherent flammability and easily breeding bacteria property of ABS polymeric materials, thereby facilitating wide applicability of ABS composites. Here, an interface engineering strategy was proposed, wherein polyethyleneimine (PEI)-modified silver nanocubes (AgNCs) was firmly assembled on MXenes via electrostatic interaction to construct 0D–2D hierarchical MXene-based nanohybrids (MXene@PEI@AgNC). The MXene was protected and the interface compatibility between MXene-based nanohybrid and ABS matrix was enhanced. Results revealed that the unique hierarchical structure of the composite promoted enhanced dispersion of MXene@PEI@AgNC in the ABS matrix. Combustion tests showed that 1.0 wt%MXene@PEI@AgNC provided the ABS with effective fire safety. Moreover, ABS-1.0 wt%MXene@PEI@AgNC exhibited a 31.88 % decrease in peak heat release rate, a 39.60 % decrease in peak smoke release rate, a 41.50 % decrease in peak CO2 production rate, and a 50.04 % reduction in the smoke factor. Meanwhile, 1.0 wt%MXene@PEI@AgNC improved the tensile strength of ABS-1.0 %MXene@PEI@AgNC (+18.1 %) without reducing the elongation at break. They also enhanced the antibacterial properties of ABS-1.0 %MXene@PEI@AgNC. This study proposed a novel and feasible approach to address the interfacial stability of MXene and to construct MXene-based hierarchical nanoblends, thereby facilitating the wide practical applications of polymeric nanomaterials in industry.

Cholecalciferol Exhibits no Antibacterial Effect on Staphylococcus aureus and Escherichia coli: an in-vitro Study.

The pleiotropic effect of cholecalciferol (vitamin D3) has gained significant momentum and has been explored widely. The study aimed to investigate the antimicrobial effect of cholecalciferol against S. aureus and E. coli. An in-vitro study was performed for the antimicrobial effect of cholecalciferol against S. aureus and E. coli. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined following the broth microdilution method. The MIC value of cholecalciferol against both S. aureus and E. coli was 0.312 mg/ml, and the MBC for both organisms was 1.25 mg/ml. However, we also observed a significant antimicrobial effect in the dimethyl sulfoxide (DMSO) control at 12.5% (v/v). Therefore, the observed antimicrobial effect may be attributed to DMSO, indicating cholecalciferol does not directly inhibit S. aureus and E. coli. This study indicates that cholecalciferol does not directly inhibit S. aureus and E. coli. Hence, we suggest exploring the antibacterial properties of other vitamin D analogs, such as calcitriol or its synergetic effect with other antimicrobial agents.

Spatially controllable fluid hydrogel with in-situ electrospinning PCL/chitosan fiber for treating irregular wounds

Skin injuries sustained during exercise are often irregular in shape and frequently accompanied by infections. Bacteria residing in the crevices of these wounds can lead to persistent infections. Routine wound monitoring, which requires removing the wound dressing to assess recovery, is inconvenient and increases the risk of infection. To address this, we prepared a polyvinyl alcohol/polyhydroxylated fullerenes ((PVA/PHF) hydrogel with good fluidity and photothermal antibacterial properties, which can penetrate into the crevices of irregular wounds. After the hydrogel was applied to the wound, the hydrogel was locally defined by the polycaprolactone/Chitosan (PCL/CS) membrane of in-situ electrospinning, which effectively killed bacteria, and the healing efficiency was increased by 240 % in the wound healing experiment. The PVA/PHF hydrogel exhibits excellent electrical conductivity, making it suitable for real-time monitoring of human body motion as a strain sensor. This capability provides doctors with an accurate basis for wound assessment. At the same time, the hydrogel can achieve self-healing within 1.5 s and withstand up to 2200 % tensile strain, which can be used for large-scale motion monitoring of the human body. This flowable hydrogel, capable of penetrating wound crevices, offers a dual function of both treatment and monitoring.

Anti-flammable, anti-fouling, anti-bacterial treatment of cotton fabrics with MOF-based hybrid coatings for highly efficient oil-water separation

A flame-retardant and hydrophobic coating was deposited on the surface of the cotton fabric via a two-step spray deposition technique. Specifically, the coating was composed of flame retardant components (guanidine phosphate) and hydrophobic species (Ti-MOF and bis(3-aminopropyl)-terminated poly(dimethylsiloxane) (PDMS)) and crosslinked with glutaraldehyde. The limiting oxygen index (LOI) of the coated cotton fabrics increased from 18.0 % to 32.0 % (15#) and 26.5 % (15#-Ti-PDMS) relative to that of the original cotton fabric, and the coated cotton fabrics also self-extinguished in the UL-94 flammability test. Compared with that of the original cotton fabric, the PHRR of the coated fabrics was significantly lower, reaching 80 %. The coated cotton fabrics (15# and 15#-Ti-PDMS) had good antibacterial properties against Staphylococcus aureus (S. aureus). In addition, 15#-Ti-PDMS had high hydrophobicity, good washing and abrasion resistance and good water-oil separation performance. Its water contact angle was 146°. The water contact angle remained above 130° after 10 laundering cycles and 50 scratch cycles. Even under strongly acidic and basic conditions, the water-oil separation efficiency of 15#-Ti-PDMS was greater than 99 %, and it was still greater than 90 % after 10 cycles. Therefore, a simple and effective method for preparing flame-retardant, hydrophobic and antibacterial cotton fabrics was developed.

Secondary Metabolite Profiling and Antibacterial Activities of Indigenous Serratia marcescens

Serratia marcescens produces secondary metabolites, which are bioactive chemicals generated during its non-essential metabolic activities. These secondary metabolites are renowned for their antibacterial, antifungal, and anticancer capabilities. This work analyzed the chemical composition and antibacterial properties of the secondary metabolite of Serratia marcescens isolated from the local environment. Serratia marcescens was isolated using standard microbiological techniques and identified based on morphological and biochemical characteristics. Gas chromatographymass spectrometric analysis revealed the presence of eighteen (18) bioactive compounds, comprising oleic acid as the most abundant compound (21.9013 %), 9,12-Octadecadien-1-ol, (Z, Z)- (11.9854 %), and other compounds with less than 6 % abundance. The metabolite has antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Bacillus subtilis. Antibacterial activity was higher against Bacillus subtilis (42.00±2.65 mm) and Proteus vulgaris (32.67±1.15 mm), and least with Pseudomonas aeruginosa (10.00±2.00 mm) at 400 mg metabolite concentration. The antibacterial effect decreased with a decrease in the concentration of the metabolite. The results show that Serratia marcescens exhibits potential as an antibacterial agent within the pharmaceutical and food sectors.

РАЗРАБОТКА МЯГКОЙ ЛЕКАРСТВЕННОЙ ФОРМЫ НА ОСНОВЕ РАСТИТЕЛЬНОГО СЫРЬЯ ОЛЕНЬЕГО МХА (CLADONIA RANGIFERINA), ОБЛАДАЮЩЕГО АНТИСЕПТИЧЕСКИМ ДЕЙСТВИЕМ

Relevance. Contemporary realities dictate the need to search for and create new medicines, including extracts obtained from plant raw materials. The use of medicinal plants often turns out to be more favorable in terms of economic and therapeutic effectiveness, sometimes very profitable. This is especially true with regard to drugs against infectious pathogens, since many of them have developed resistance to antibiotics. Lichens are known to contain substances with antibacterial properties. Among the extracted components from lichens, usnic acid is considered one of the most promising. Work is underway to include it in the composition of dosage forms for treatment. The development of drugs for external use that contain usnic acid is considered the most studied and preferred. The aim Design of a soft medicinal form (gel) based on vegetable raw materials of Deer moss (Cladonia rangiferina), which has an antiseptic effect. Materials and methods. The materials for the creation of an antiseptic gel were: usnic acid extract isolated from Deer moss (Cladonia rangiferina); substances that form the basis of gel dosage forms (carbopol, polyethylene glycol). 3 experimental series of gel containing usnic acid have been produced. Their organoleptic and physico-chemical properties have been studied. The results of the study. Based on the results of a series of experiments, the best composition for the preparation and production of a gel containing usnic acid was determined. It includes the following component ratios: extract of usninic acid from alcohol berry 1:10 (20 ml); carbopol (0.8 g); polyethylene glycol-6000 (0.1 g). The conclusion the optimal composition of an antiseptic gel containing usnic acid has been determined. A recipe has been compiled for the manufacture of gel based on vegetable raw materials of Deer moss.

Silver nanoparticles in medicine and technology: Synthesis, functionality and future prospects

Nanomaterials, particularly nanoparticles (NPs), have emerged as forefront materials of the 21st century due to their unique properties and potential applications. Silver nanoparticles (AgNPs) are among the most attractive inorganic nanomaterials, widely used due to their significant antibacterial properties, broad-spectrum activity, and potential applications across various fields, including health, food storage, textiles, and environmental solutions. AgNPs exhibit a large surface-area-to-volume ratio, enabling enhanced interaction with bacterial cells, making them effective in medical and industrial applications. Despite concerns over their toxicity, AgNP-based products have been approved by multiple regulatory bodies. Nanoparticle synthesis methods are generally divided into physical, chemical, and biological approaches. Although physical and chemical methods are efficient, they involve toxic chemicals and energy-intensive processes. Biosynthesis, particularly plant-based, offers an eco-friendly alternative, reducing the environmental and health risks associated with chemical agents. The review also explores the therapeutic potential of AgNPs in drug delivery systems, especially in topical formulations like nanoemulsions, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs). These nanocarriers enhance drug stability, skin penetration, and controlled release, making them ideal for dermal and transdermal delivery. Moreover, the use of AgNPs in dentistry is highlighted for their bactericidal properties, which help prevent infections and implant failure, with the potential for enhancing therapeutic outcomes without common drawbacks like tooth staining. Overall, AgNPs exhibit promising applications in biomedical, pharmaceutical, and dental fields, and their novel functionalities continue to advance the development of nanotechnology-driven solutions.

Study the phytochemical, Biological and pharmacological aspects of Azadirachta indica: A review

Neem (Azadirachta indica) is a fast-growing tropical evergreen plant that belongs to the Meliaceae family. Its compounds have been shown to be effective against illnesses and insect pests that are significant economic concerns. The plant's whole body has biopesticidal properties, especially in the form of extracts from the leaves, bark, and roots. Every part of the plant has been utilized medicinally and is now considered a treasure in contemporary medicine. Salannin, quercetin, nimbolinin, nimbin, nimbidin, nimbidol, and azadirachtin are among the beneficial active compounds that have been isolated from several plant sections. This review article's primary goal is to provide information on a range of pharmacological activities, including anti-inflammatory, anti-cancer, anti-bacterial, antiviral, antifungal, antihelmethic, antidiabetic, wound-healing, and ulcer-preventing properties. activity hepatoprotective, Effects on Immunomodulation and Antinephrotoxicity.

Prim-O-glucosylcimifugin alleviates influenza virus-induced pneumonia in mice by inhibiting the TGF-β1/PI3KCD/MSK2/RELA signalling pathway.

Prim-O-glucosylcimifugin (POG) is a chromone derived primarily from Saposhnikovia divaricata (Turcz) Schischk and Cimicifuga simplex. Previous research has shown that POG possesses antibacterial, anticancer, anti-inflammatory, antioxidant, anticonvulsant, antipyretic, and analgesic properties. However, the specific impact of POG on influenza-virus-induced pneumonia is not well understood. In this study, we investigated the protective effects and underlying mechanisms of POG in pneumonia caused by influenza A virus (IAV). In vitro, POG was found to have a protective effect against infections caused by the respiratory viruses respiratory syncytial virus (RSV), human coronavirus OC43, and influenza A virus. POG inhibited A/FM/1/1947(H1N1) infection with an EC50 ranging from 3.01 to 10.43 in vitro. Intraperitoneal infection of mice with POG at a dose of 5 or 10 mg/kg resulted in a reduction in IAV-induced pneumonia, as evidenced by decreased pulmonary edema, improved lung histopathology, and reduced inflammatory cell accumulation. At the higher dose (10 mg/kg), POG treatment significantly increased survival rates, decreased viral titres in the lungs, improved lung histology, and reduced lung inflammation in IAV-infected mice. POG also effectively alleviated pulmonary fibrosis by reducing the levels of fibrotic markers (hydroxyproline [Hyp] and transforming growth factor β1 [TGF-β1]) and suppressing the expression of alpha smooth muscle actin (α-SMA), p focal adhesion kinase (p-FAK), and TGF-β1 in lung tissues. In addition, POG inhibited the expression of the RELA proto-oncogene (RELA), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD), and mitogen- and stress-activated protein kinase 2 (MSK2) in lung tissues. These results indicate that POG may have a protective effect against IAV-induced pneumonia by downregulating the TGF-β1/PI3KCD/MSK2/RELA signalling pathway in the lungs.

Antibacterial and cytotoxic properties of esterified α- lactalbumin and β-lactoglobulin

α -Lactalbumin ( α -La) or β -lactoglobulin ( β -Lg) were esterified with methanol. Native proteins and their methylated esters (Est. α -La and Est. β -Lg) were tested for their antibacterial and cytotoxic properties. Esterification extents for Est. α -La and Est. β -Lg were 92% and 88%, with isoelectric points at pH 8 and 10, respectively. The Est. α -La and Est. β -Lg were more inhibiting the growth of pathogenic bacteria compared to the corresponding native proteins. The impact of esterified α -La and β -Lg on MCF-7, A549, and Caco-2 cell lines was assessed and revealed that the concentration inhibiting 50% cellular growth (IC50) for Est. α -La recorded 107.93 µg/mL against MCF-7, 616.44 µg/mL against A-549, and 388.23 µg/mL against Caco2. In parallel, Est. β -Lg achieved IC50 at 101.35, 420.84, and 234.16 µg/mL, against MCF-7, A-549, and Caco2, respectively. Esterified proteins may serve as therapeutic antimicrobial agents against pathogenic bacteria and cytotoxic agents against specific cancer cells.

Water-soluble chlorogenic acid-chitosan and polydatin-chitosan conjugates: antibacterial activity and inhibition of lipid and protein oxidation.

Chitosan (CS), an abundant alkaline polysaccharide, is valued for its biocompatibility, non-toxicity, and antibacterial properties. However, its limited solubility and modest antioxidant activity constrain its utility. Grafting polyphenols onto chitosan through the use of grafting reactions can enhance both the solubility and bioactivity of chitosan. Among the techniques employed, the free radical grafting method is favored for its simplicity, environmental sustainability, and its effectiveness in preserving biological activity. In this study, chlorogenic acid (CGA) and polydatin (PLD) were conjugated successfully to chitosan by a Vc/H2O2 redox system. Analytical techniques such as ultraviolet-visible (UV-visible) spectroscopy, fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and proton nuclear magnetic resonance (1H NMR) were employed to confirm the formation of covalent bonding between the polyphenol molecules and the chitosan backbone. The novel conjugates displayed superior antioxidant properties in comparison with pristine chitosan, as evidenced by their enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, and hydroxyl radical scavenging capacities, and Fe2+ reducing power. Both CGA-CS and PLA-CS exhibited excellent lipid and protein oxidation inhibition capabilities. Furthermore, the conjugates were shown to have significant antibacterial effects against four common pathogenic bacteria: Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas putida, and Staphylococcus aureus (P < 0.05). The newly synthesized water-soluble polyphenol-chitosan conjugates demonstrated remarkable biological activity, particularly CGA-CS. This study offers new insights and a strong theoretical foundation for developing natural food preservation materials with potential applications in the food industry. © 2024 Society of Chemical Industry.