Future Antimicrobials: Natural and Functionalized Phenolics

Advances of novel hydrogels in the healing process of alveolar sockets

Tooth extraction is a common oral surgical procedure that often leads to delayed alveolar socket healing due to the complexity of the oral microenvironment, which can hinder the patient's aesthetic and functional recovery. Effective alveolar socket healing requires a multidisciplinary approach. Recent advancements in materials science and bioengineering have facilitated the development of innovative strategies, with hydrogels emerging as ideal restorative materials for alveolar socket repair due to their superior properties. This review provides an overview of recent advances in hydrogels for alveolar socket healing, focusing on their classification, physical properties (e.g., mechanical strength, swelling behavior, degradation rate, and injectability), biological functions, and applications in relevant animal models. Specifically, the bone-regenerative and antimicrobial properties of hydrogels are highlighted. Furthermore, this review identifies future directions and addresses challenges associated with the clinical application of hydrogels in extraction socket healing.

Antioxidant capacities and in vitro anti-microbial activities of rice (Oryza sativa var Bajong) from Borneo

Rice contains antioxidants and phenolic components that exert anti-inflammatory and anticancer properties. Different geographical areas produce rice with various chemical constituents and phytochemicals, in turn these confer differential protective effects including antimicrobial and anticancer properties. Sarawak rice, Oryza sativa var Bajong (Bajong), a fragrant dark purple rice grain harvested from two locations in Sarawak, namely interior Lubok Nibong (LN) and coastal Sri Aman (SA), was assessed for their antioxidant properties and antimicrobial activities. The rice was extracted using methanol solvent and evaluated for total phenolic content (TPC), total flavonoid contents (TFC), as well as their antioxidant and antimicrobial activities based on the Folin-Ciocalteu assay, the aluminium calorimetric method, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and disk diffusion assay, respectively. Using dual-wavelength measurement, Bajong LN showed 2.16% higher amylose content than Bajong SA. Furthermore, 24-h extract of Bajong LN and 48-h extract of Bajong SA exhibited high antioxidant properties (34-70 µg/mL) and were rich in phenolic (46.54 ± 2.62 mg GAE/g; 25.28 ± 3.91 mg GAE/g) and flavonoid contents (5.53 ± 0.36 mg QCE/g; 7.7 ± 2.19 mg QCE/g) respectively. It is interesting to note that 72-h Bajong extract exhibited the largest zone of inhibition (9-9.3 mm) against Gram-negative Pseudomonas aeruginosa (Ps. aeruginosa), which correlated to the high TPC and TFC despite a reduction of antioxidant activity due to prolonged extraction hours. These significant results conferred added value to a staple, health-promoting Bajong had warranted it to be further investigated as a nutraceutical and pharmaceutical crop.

Strontium-based quaternary ammonium salt chitosan particles for ultrafast hemostasis of open fracture

The management of open bone defects poses a formidable challenge in clinical practice, primarily due to issues such as profuse bleeding, inflammation, bacterial infections, and compromised bone fracture healing. To tackle these complexities, we have devised a novel hemostatic powder, namely the compound strontium-based chitosan quaternary ammonium salt hemostatic powder (QCS@SrT-TA). This innovative powder leverages the self-assembly of tripolyphosphate and strontium ions, facilitated by a positively charged core cross-linker. Furthermore, its surface has been strategically modified with polyphenol and positively charged macromolecules, imparting unique properties. The mesoporous architecture of QCS@SrT-TA facilitates rapid moisture absorption, enhancing its efficacy. In preclinical studies using rat tail artery amputation and liver bleeding models, QCS@SrT-TA exhibited remarkable performance, significantly reducing both bleeding time and volume (62.39 ± 2.89 mg, 35.33 ± 4.16 s in tail amputation, 63.7 ± 5.19 mg, 62.33 ± 9.61 s in liver bleeding). Notably, the positively charged strontium ions and quaternary ammonium salts within the powder were effective in removing bacteria, minimizing the risk of infection. Beyond hemostasis, QCS@SrT-TA demonstrates additional therapeutic benefits. It polarizes M2 macrophage phenotypes and promotes angiogenesis within bone defect sites, accelerating bone healing processes. Ultimately, a substantially enhanced and notable functional recovery is achieved. In summary, the rapid hemostatic, potent antibacterial, anti-inflammatory, and angiogenesis-promoting characteristics of QCS@SrT-TA hold immense promise as a groundbreaking clinical treatment strategy for open bone defects.

Extraction of phenolic compounds from Pfaffia glomerata leaves and evaluation of composition, antioxidant and antibacterial properties

This work aimed to evaluate the extraction conditions of total phenolic compounds (TPC) from Pfaffia glomerata leaves (PGLs) and characterize the extract obtained in the best conditions. Aqueous extraction was performed in a Shaker, varying the levels of rotation (100, 150, 200 rpm), temperature (30, 45, 60° C) and mass to volume (w v-1) ratio (1:10, 1:20, 1:30 g ml-1). The variables w v-1 ratio and temperature, and their combination, showed a positive effect (p<0.05) in TPC extraction. The time of extraction increased TPC extraction until 30 min, thereafter, the values decreased. The extraction performed at 60o C, 1:30 g ml-1, 125 rpm and 30 min allowed to reach the maximum TPC content (11.94 mg g-1). This extract contains β-ecdysone (4.64 g 100g-1), a chemical marker of P. glomerata, and, phenolic compounds, as gallic acid (28.51 mg 100g-1) and catechin (24.82 mg 100g-1). PGLs extract exhibits antioxidant activity by the in vitro methods evaluated (iron reduction powder and radical scavenging ability). Antibacterial activity was also detected, being found the minimum inhibitory concentration of 20 mg mL-1 for Escherichia coli and Pseudomonas aeruginosa. Therefore, PGL extract had a potential application as natural antioxidant and antimicrobial in food or pharmaceutical products.

Characterizing the Sulfated and Glucuronidated (Poly)phenol Metabolome for Dietary Biomarker Discovery

(Poly)phenols, bioactive compounds abundant in plant-based diets, have attracted interest for their potential role in preventing chronic diseases including cardiometabolic and neurodegenerative diseases. This study investigates the global sulfatome and glucuronidated metabolome in urine samples from 100 healthy adults collected pre- and postintervention following a 3-day (poly)phenol-rich intervention consisting of flaxseeds, raspberry powder, and soy milk. Using untargeted mass spectrometric metabolomics combined with selective phase II enzymatic treatment, we detected 156 sulfated and 143 glucuronidated metabolites in urine samples. Significant changes postintervention were observed for 91 sulfates and 94 glucuronides. Receiver operating characteristic curve analysis identified a combination of six polyphenol-derived key metabolites: glucuronidated daidzein and the sulfated compounds of pyrogallol, ferulic acid, 4-methoxyphenol, enterolactone, and resorcinol, which resulted in the best combination with the highest predictive AUC of 0.97. These findings underscore the utility of these metabolites as sensitive and selective biomarkers of (poly)phenol dietary intake.

Almond By-Products: A Comprehensive Review of Composition, Bioactivities, and Influencing Factors

One of today's major environmental and economic challenges is the fight against both agro- and industrial-waste. Almond production and industrial processing exemplifies this issue, as it generates tons of waste and by-products, with hulls and shells accounting for about 70% of the total fruit's weight while skins represent about 6% of the shelled kernel. Since the edible kernel, about 23% of the total fruit weight, holds the highest commercial value, there has been growing interest within the scientific community in exploring the potential of these by-products. However, almond by-products contain a wide range of phytochemicals, mainly phenolic compounds (flavonoids and non-flavonoids), and triterpenoids, with great potential as antioxidant, antimicrobial, anti-inflammatory, and prebiotic properties. Although these by-products are being explored as alternative sources in the textile, pharmaceutical/cosmetic, and food industries, their primary use remains in livestock feed or bedding, or as biofuel. This review compiles recent scientific data on almond by-products' phytochemical composition and bioactivities aiming to support sustainable and holistic agricultural practices.

GC-MS Analysis of Polysaccharides from an Intergeneric Hybrid of Pleurotus florida and Cordyceps militaris: A Comparative Study

Edible and medicinal mushrooms are valuable sources of polysaccharides, known for their dual roles as immunostimulants and immunosuppressants. This study aimed to enhance polysaccharide content by fusing two mushroom species, P. florida and C. militaris, while exploring their antioxidant and antibacterial potential. These mushrooms have diverse health benefits, including lowering high cholesterol, providing anti-inflammatory effects, supporting diabetes management, aiding in cancer treatment, and enhancing the efficacy of COVID-19 vaccines. Successful hyphal fusion was achieved, and optimal culture conditions were determined using response surface methodology. The hybrids exhibited superior growth compared to the parental strains. Hyphal fusion improved several attributes, resulting in diverse hybrids with increased biomass and metabolite production. FTIR analysis confirmed the presence of exopolysaccharides, with concentrations measured at 28.4 g/L (P1), 31.50 g/L (CD), and 36.74 g/L (F3). GC-MS analysis identified various bioactive metabolites, including a higher concentration of dimethyl palmitamine in the hybrid, a novel compound, butanenitrile, 2-(methoxymethoxy), which was not found in the parental strains. These compounds are likely responsible for the enhanced antimicrobial and antioxidant activities.

Starch based films and coatings for food packaging: Interactions with phenolic compounds

Biodegradable starch based films and coatings have been a research focus for food packaging. Phenolic compounds have many benefits for food and health applications. This review summarized the recent advances in the development of starch based films and coatings with added phenolic compounds and extracts. The impact of the added phenolic compounds and extracts on physicochemical, mechanical, barrier, antioxidant and antimicrobial properties of starch films and coatings were described. The starch films and coatings with added phenolics were applied in the packaging of both plant and animal based food products with increased shelf life. For intelligent packaging, anthocyanins were formulated into the starch films and coatings to reflect the degree of food freshness. Composite starch materials with the addition of nanoparticles, proteins and other polysaccharides were also formulated to improve the mechanical and biological functions of the films and coatings. Significant limitations in the studies were noted due to the lack of understanding of the nature of starch-phenolics interactions at the molecular level. Overall, optimal formulations of added phenolic compounds and extracts should be obtained to have targeted mechanical, barrier, and biological properties.

Parametric optimization, Polyphenol profiling and Bioefficacy of Bacopa monnieri (L.) Pennell phytoextract against multi-drug resistant (MDR) foodborne bacterial pathogens

Nowadays, antimicrobial resistance and foodborne burden are a prevalent global concern for human health and sustainable development. In this context, this study aimed to investigate the effect of Bacopa monnieri (L.) Pennell extract against pathogenic foodborne bacteria (Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes). Antibiogram phenotypic analysis on these strains revealed a high multiple antibiotic resistance (MAR) index, which varies from 0.5 to 0.75, and antibiotic resistance of 50-80 per cent. Polarity-wise extracted ethanolic extract (BM04-ET) showed potent anti-listerial (22.33 ± 1.15 mm) and anti-escherichial (20.33 ± 0.58 mm) potential with strong bactericidal activity against tested strains. In vitro phytochemical experiments confirmed a very high content of phenols (214.2 ± 1.79 mg/g and flavonoids (61.01 ± 0.48 mg/g) in BM04-ET; further confirmation via UPLC elucidated the abundance of natural bioactive flavanonol, i.e., dihydroquercetin (224.932 μg/mL), possibly imparting bactericidal property to extract. Optimization studies identifies the best parametric combination with pH value of 6.8, temperature 37 °C, and incubation period of 24 h for the antibacterial effect of BM04-ET. Due to high polyphenolic content and superior antibacterial excellence, the study suggested B. monnieri ethanolic extract could be used as a choice in combating foodborne infection, and further research exploration on key antibacterial components turn out to be a remarkable milestone in food and medicinal industries.

Preparation, antioxidant, antibacterial, and in vivo evaluation of pomegranate flower extract nanofibers based on thiolated chitosan and thiolated gelatin for treating aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is a common condition that manifests as ulcerative lesions in the oral mucosa. In this study, bilayer, mucoadhesive nanofibers loaded with pomegranate flower extract (PFE) were prepared using thiolated gelatin (TGel) and thiolated chitosan (TCS) as the active layer and drug-free polycaprolactone (PCL) as the backing layer. Gelatin (Gel) and chitosan (CS) were successfully thiolated (proven by Ellman's assay, solubility, 1H NMR, FTIR, Raman spectroscopy, and XRD) and electrospun into active nanofibrous layers with a diameter of 356.9 nm. The in vitro release assay showed extended release of PFE, reaching about 57 % drug release in 48 h, fitted to the Korsmeyer-Peppas kinetics. FTIR, Raman spectroscopy, and XRD also showed the characteristic peaks of the nanofibers and their components. The nanofibers also exhibited significant hydrophilicity (contact angle of 47-49°), mucoadhesion (432.7 Pa), antioxidant capabilities (93.3 ± 0.2 %), and antibacterial effects against Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, PFE-loaded thiolated nanofibers significantly accelerated wound healing and epithelial tissue regeneration in vivo, reducing the ulcer area from 187 ± 19 mm on the 1st day to 68 ± 6 on the 7th day. Overall, bilayer PFE-loaded nanofibers based on TCS and TGel showed promising potential for treating RAS.

The Role of Crosslinking Agents in the Development of Collagen-Hydroxyapatite Composite Materials for Bone Tissue Engineering

The lack of bone grafts represents a major issue in the orthopedic field, reconstructive surgery, and dentistry. There are several bone conditions that often demand the use of grafts, such as fractures, infections, and bone cancer. The number of bone cancer cases increased in the past few decades and along with it, the need for bone grafting materials. To avoid the use of autografts and allografts there has been an increased interest towards synthetic grafts. This research aims to develop some collagen/hydroxyapatite (Coll/HAp) scaffolds cross-linked with three different agents that could be used in bone tissue engineering (BTE). These scaffolds were obtained with a freeze-drying method after the in situ formation of hydroxyapatite inside the collagen matrix. They were structurally and morphologically characterized and evaluated in terms of antimicrobial activity on E. coli and S. aureus bacterial strains. The results revealed that the scaffolds have porous structures with interconnected pores of suitable dimensions and well-distributed inorganic phases. Coll/HAp samples showed great antibacterial activity even without the use of typically used antibacterial agents. These findings allow us to conclude that these scaffolds are promising candidates for use in BTE and bone cancer treatment after the incorporation of specific antitumoral drugs.

Antibiofilm Effects of Plant Extracts Against Staphylococcus aureus

The global rise in antimicrobial resistance poses a significant threat to public health, necessitating alternative therapeutic options. One critical challenge is treating infections caused by biofilm-forming bacteria, which are notably resistant to conventional antibiotics. Staphylococcus aureus, including methicillin-resistant strains (MRSA), is a major pathogen in biofilm-related infections, complicating treatment and leading to chronic cases. Plant extracts have emerged as promising alternatives, offering new avenues for effective treatment. This study evaluated the antibacterial and antibiofilm activities of commercial extracts of Vitis vinifera L. (grape), Camellia sinensis L. (green tea), Olea europaea L. (olive), Quercus robur (oak), and Coffea arabica L. (coffee) against S. aureus strains from ATCC collections and clinical isolates. Preliminary screening using the disk diffusion test assessed the zones of inhibition, which was followed by minimum inhibitory concentration (MIC) determination via broth microdilution, with Quercus robur L. showing the best overall MIC results. The results obtained demonstrate the strong antibacterial activity of the extracts, with the MIC values ranging from 0.2 to 12.4 mg/mL. Using the XTT reduction assay, the extracts inhibited biofilm growth by 80-85% after 24 h of incubation, with Coffea arabica L. achieving interesting antibiofilm activities. These findings suggest that the investigated plant extracts hold potential as antimicrobial agents and biofilm inhibitors, offering an alternative approach to tackling antimicrobial resistance. Further research is needed to explore their potential applications in developing novel adjuvant therapies.

Evaluation of Antibacterial and Antibiofilm Properties of Phenolics with Coumarin, Naphthoquinone and Pyranone Moieties Against Foodborne Microorganisms

Numerous studies have previously demonstrated the antimicrobial activity of plant extracts rich in procyanidins. However, these investigations that focused on uncharacterized extracts do not provide information on the structure-activity relationships of these compounds. The aim of this work was to investigate the antibacterial and antibiofilm properties of 27 phenolics with coumarin, naphthoquinone and pyranone moieties against foodborne microorganisms, as well as to establish structure-activity relationships. Minimal inhibitory concentrations (MICs) for each compound were investigated, as well as their ability for inhibiting biofilm formation as well as disrupting previously formed biofilms by food pathogens. Our compounds show high antibacterial and antibiofilm activities against Gram-positive bacteria. Regarding the structure-activity relationships observed, the coumarin moiety seems to favor the antibacterial activity against both S. aureus strains assayed, while a naphthoquinone moiety enhances antibacterial effects against B. cereus. Moreover, the replacement of OH groups in the B-ring by methoxy groups impairs antibacterial activity of the compounds against target bacteria, while the presence of Cl or OH groups in the molecules seems to enhance the inhibition of biofilm formation as well as the disruption of preformed biofilms. These results may be of great relevance for the food sector, increasing the options of additives that can be used industrially.

Phytochemical Analysis and Allelopathic Potential of an Aggressive Encroacher Shrub, Euryops floribundus (Asteraceae)

Euryops floribundus is an encroaching shrub species that poses a threat to grassland diversity and productivity in the Eastern Cape region of South Africa. This shrub inhibits understory herbaceous plant recruitment and establishment, thereby exposing soils to erosion, owing potentially to toxins it secretes. However, the allelochemicals of E. floribundus and their potential effects on the germination and establishment of plants remains poorly understood. We investigated the phytochemical classes of leaves and twigs of E. floribundus and evaluated the effects of extracts from these plant parts on seed germination and seedling growth of Lactuca sativa through a laboratory experiment. In the laboratory, we analysed phytochemicals in leaf and twig extracts and tested their allelopathic effects on Lactuca sativa seed germination and growth using the Petri dish method. In this proof-of-concept study, we identified 12 phytochemical classes of E. floribundus. Quantitative analysis showed that the leaves had significantly higher levels of flavonoids, phenolics, and tannins than twigs. As a result, leaf extracts caused 100% inhibition of seed germination, while twig extracts inhibited seed germination by 90% at 50 g L-1. Both leaf and twig extracts also significantly reduced radicle and plumule growth, with a stronger effect observed from the leaves than twigs. This study provides new insights into the phytochemical composition and strong allelopathic potential of E. floribundus, contributing to a better understanding of the mechanisms driving its encroachment in semi-arid grasslands.

Wild-Grown Romanian Eupatorium cannabinum: Advancing Phyto-Nanocarriers via Maltodextrin Micro-Spray Encapsulation-Metabolite Profiling, Antioxidant, Antimicrobial, and Cytotoxicity Insights

In Romanian ethnopharmacology, Eupatorium cannabinum species is known for its remarkable biological activity. We present an advanced approach to encapsulation using maltodextrin matrices to enhance the stability and efficacy of phytoconstituents and nanoparticles. Two distinct carrier systems were developed: (i) a direct micro-spray encapsulation of E. cannabinum in maltodextrin to produce a maltodextrin-encapsulated carrier (MEC), and (ii) a two-step process involving the preparation of a new phytocarrier system based on gold nanoparticles (EC-AuNPs), followed by micro-spray encapsulation in maltodextrin to create the maltodextrin-encapsulated AuNPs system (MEC-AuNPs system). Comprehensive chemical profiling using GC-MS and ESI-QTOF-MS revealed 80 bioactive molecules, including terpenoids, alkaloids, flavonoids, and phytoecdysteroids. Morpho-structural (XRD, FTIR, Raman spectroscopy, SEM) and thermal analyses confirmed the successful integration of NPs within the matrices. EC-AuNPs and MEC-AuNPs exhibited superior antioxidant activity, significant antimicrobial efficacy against major bacterial pathogens (S. aureus, B. subtilis, B. cereus, P. aeruginosa, S. typhi, and E. coli), and enhanced cytotoxicity against MCF-7 and HT-29 cancer cell lines. This study highlights the potential of combining E. cannabinum with AuNPs and maltodextrin encapsulation to develop multifunctional therapeutic systems. The findings underscore the importance of phytoconstituent stabilization and nanotechnology in addressing global antimicrobial resistance and advancing innovative medical applications.

Harnessing Plant-Derived Terpenoids for Novel Approaches in Combating Bacterial and Parasite Infections in Veterinary and Agricultural Settings

The rising resistance to conventional antimicrobial therapies in veterinary contexts poses a formidable challenge. While various innovative treatment strategies for pathogenic infections have emerged, their success still needs to be improved, warranting continued research. Recent investigations into natural products as potential sources for biologically active therapeutics have gained traction. Phytochemicals present a promising alternative in combating a spectrum of pathogens, including bacteria, fungi and parasites. One such class of phytochemicals with mounting potential is the structurally diverse terpenes. These chemicals contribute to plants' characteristic odour and medicinal effects and have been widely investigated in the scientific literature for their exceptional antibacterial activity. Their efficacy is demonstrated through diverse mechanisms, encompassing damage to bacterial membranes, suppression of virulence factors, and interference with enzymes, toxins, and biofilm formation. This review comprehensively examines terpenes' in vitro and in vivo activity and their derivatives against pathogens, elucidating their potential against antimicrobial resistance (AMR) and the underlying mechanisms specific to each terpene class. The findings underscore the burgeoning potential of terpene therapy as a viable alternative or supplementary approach to conventional antibiotics in addressing bacterial and parasitic infections in livestock and companion animals.

Phytochemical Profiles, Antimicrobial and Antioxidant Activity of Knautia integrifolia (L.) Bertol. subsp. integrifolia

The genus Knautia (L.) (Caprifoliaceae) is widely distributed in the Mediterranean region and is represented by 11 species of flora in Turkey. This study conducted a detailed phytochemical investigation of the methanol extract of the whole plant of K. integrifolia using a combination of LC-ESI-FT-MS and NMR analyses. According to the results of this analysis, 25 compounds were identified in the methanol extract of K. integrifolia. The extract is particularly rich in phenolic secondary metabolites, including phenolic acid derivatives, flavonoid glycosides, and flavones, along with the presence of triterpenoid compounds. Additionally, the total phenolic content of the K. integrifolia methanol extract was evaluated. Considering the pharmacological activities reported for Knautia species, the antioxidant potential of the methanol extract was assessed using the DPPH radical scavenging assay, resulting in a value of 77.5% when compared to the ascorbic acid standard. In this study, antimicrobial activity tests were performed on K. integrifolia methanol extract for the first time. The results indicated that the extract demonstrated greater susceptibility to Staphylococcus epidermidis compared to the control group. At the same time, Pseudomonas aeruginosa exhibited a minimum inhibitory concentration value, indicating high sensitivity to the methanol extract.

Thermal survival patterns of Staphylococcus aureus in sous vide seabream treated with quince leaf extract

Staphylococcus aureus is a major cause of gastroenteritis, commonly associated with the consumption of food contaminated at any stage of the food supply chain. Sous vide seafood has the potential to be a vehicle for the spread of S. aureus and enterotoxins due to low temperature cooking. This study aimed to investigate the antimicrobial activity of quince leaf extracts and the impact on the survival of S. aureus during sous vide process at frequently utilized temperatures. The results of the disk diffusion assay demonstrated the antibacterial efficiencies of extracts obtained using ethanol and methanol, with inhibition zone diameters of 9.8 and 11.2 mm, respectively. In contrast, aqueous extract had no effect on the bacteria. Since methanolic extract was the most effective one, phenolic profile was analyzed. Quercetin-3-O-rutinoside was the major compound (43.0 %) followed by 3-O-caffeoylquinic acid (21.8 %). Quince leaf methanolic extract (QM) was added to seabream to examine the thermal inactivation kinetics of S. aureus. The D values of QM-treated group ranged from 9.80 and 0.39 min, while those of the untreated samples varied between 11.36 and 0.51 min at 56-62 °C. The addition of QM to sous vide seabream significantly reduced the time needed to inactivate S. aureus. The z values of S. aureus in QM and untreated groups were 4.19 and 4.32 °C, respectively. Beneficial results could be achieved by adding quince extracts thereby; reducing S. aureus in sous vide fish and enhancing food safety. Developing efficient thermal processing techniques and combining additional hurdles are promising strategies for accomplishing pathogen inhibition.

Revolutionizing seafood packaging: Advancements in biopolymer smart nano-packaging for extended shelf-life and quality assurance

Food packaging is one of the most important strategies to prevent food damage or spoilage during storage and the supply chain. Among various food types, seafood, a high-value product, is particularly vulnerable to post-harvest quality loss and microbial contamination during storage. Although current plastic-based packaging materials are durable, they pose a serious threat to the environment. Therefore, research on natural biopolymers for packaging is a top priority for scientists, industries, and government bodies. Additionally, nanoengineering concepts enhance the physicochemical and functional properties of biopolymers, thereby revolutionizing the packaging industry. This review provides a comprehensive discussion on smart nano-packaging for seafood products. It focuses on advancements in biopolymer smart nano-packaging as a transformative solution for extending the shelf life and ensuring the quality of seafood products. Existing knowledge highlights the functionality of biopolymers and nanotechnology, but gaps remain in addressing practical applications, such as scalability, cost-efficiency, and consumer safety. This review bridges these gaps by providing a detailed analysis of biopolymer-based active and intelligent packaging systems, which integrate antioxidant, antimicrobial, and freshness-indicating properties. It emphasizes the unique contributions of nanoengineering to enhance biopolymer properties, offering innovative solutions to the seafood packaging industry while promoting environmental sustainability.

Photo-responsive Cu-tannic acid nanoparticle-mediated antibacterial film for efficient preservation of strawberries

The existing films used for fruit preservation suffer from insufficient preservation abilities. This study introduces Cu-tannic acid (Cu-TA) nanoparticles, synthesized from tannic acid (TA) and Cu2+, to enhance food packaging properties. Integrated into a chitosan-gelatin (CG) matrix, the resultant Cu-TA nanocomposite films exhibit superior antibacterial efficacy and killing rates of Escherichia coli and Staphylococcus aureus more than 99 %, and double the shelf life of strawberries, underscoring the exceptional freshness preservation capabilities of film. Additionally, the tensile strength of the Cu-TA nanocomposite films increased by 1.75 times, the DPPH radical scavenging percentage increased from 29.4 % to 68.4 %, and the water vapor permeability (WVP) decreased by about 60 % compared to the pure CG films. Comprehensive cytotoxicity and migration assessments confirm the safety of film, paving the way for their application in food packaging. The excellent performance of the Cu-TA nanocomposite films positions them as a formidable solution for protecting perishable food items.

Examining the impact of hydroxy group position on antibacterial activity of copper complexes derived from vanillin-based Schiff bases: Experimental and computational analysis

The positioning of the hydroxy group plays a crucial role in the coordination of Schiff bases with copper ions and their antibacterial effectiveness. This potential is an area of interest for future exploration, although no specific studies have been conducted. This study aims to reveal the significance of the positioning of the hydroxy group in the ability of the Schiff base to coordinate with copper ion and its antibacterial efficacy against E. coli and S. aureus. By utilizing ortho-vanillin and para-vanillin as precursors, we successfully synthesized Schiff bases HL1 (ortho) and L2 (para), which were confirmed through Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) analyses. HL1 forms the CuL1 complex as a bidentate ligand with N, O donor atoms, while L2 only provides a single N donor atom, forming the CuL2 complex but retaining a free hydroxy group. Crystallographic analysis revealed a tetragonal crystal system for the Schiff base and orthorhombic for the complex. Electronic transition analysis supported by Density Functional Theory (DFT) studies indicated a distorted square plane geometry for the CuL1 and CuL2 complexes. The in vitro antibacterial assessment against E. coli and S. aureus revealed that the CuL1 and CuL2 complexes exhibited significantly better activity than Schiff bases HL1 and L2. Moreover, CuL2 exhibits greater bioactivity against both bacterial strains compared to CuL1. This difference could be attributed to a free hydroxy group, supported by computational analysis. Our findings suggest that the formation of complexes and the presence of free hydroxy groups may enhance the antibacterial activity of the drug.

Understanding the synergistic sensitization of natural products and antibiotics: An effective strategy to combat MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multi-resistant organisms found in hospital-acquired infections and is associated with high morbidity and mortality. The development of new drugs and promising therapeutic strategies against MRSA is thus an urgent request. In recent years, some natural products have been demonstrated to show great potential in improving the efficacy of antibiotics to treat various drug-resistant bacteria, particularly MRSA. In this context, we aimed to analyze systematically from the prior arts that investigated the synergy between natural products and antibiotics against MRSA. These findings not only give us a better understanding on the mechanism of actions but also shed light on the bioactive molecular scaffolds identified from diverse natural products. In the present study, we concentratedly reviewed the studies that utilized natural products to enhance the potency of conventional antibiotics against MRSA in the last decade. The timely information reported herein may give meaningful insights into the molecular design of novel and potent antibacterial agents and/or effective therapeutics to combat MRSA for practical applications.

Different Disinfection Strategies in Bacterial and Biofilm Contamination on Dental Unit Waterlines: A Systematic Review

OBJECTIVE

The aim of this systematic review is to explore the effectiveness of different methods of reducing contamination and biofilms in dental unit waterlines (DUWLs) and to provide reference for future standardisation of disinfection practices in dental clinic.

METHODS

This systematic review searched PubMed and Web of Science databases for DUWL disinfection studies from 2013 to 2023, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Synthesis Without Meta-analysis, additional extracting relevant data based on predefined inclusion and exclusion criteria.

RESULTS

The study review identified 8442 articles, with 58 included after rigorous screening. Disinfection methods for DUWLs were categorised into 14 physical and 90 chemical methods. Peroxides, chloramine-based, and biguanide methods were frequently used, often in combination. The effectiveness of these methods varied; for instance, phenolic was effective, while alcohol was not, in reducing bacterial and biofilm contamination. Biguanide, when used alone or combined with chlorine-based or alcohol, showed mixed results. Chlorine-based methods, particularly when combined with quaternary ammonium salt or enzymes, were generally effective. Enzymes and iodophor also demonstrated efficacy, though with some inconsistencies. Mechanical systems, peroxides, quaternary ammonium salts, silver, and tube coatings had varying degrees of success. Other innovative methods, such as Aloe vera and slightly acidic electrolysed water, showed promise in some studies, but the effectiveness of flushing was questioned. This comprehensive analysis highlights the diversity and complexity of disinfection strategies for DUWLs.

CONCLUSION

Future studies should focus on how material composition and tubing design affect biofilm development and the effectiveness of disinfection methods to guide the design of advanced dental units.

New Insights into the Antibacterial Activity of Hydroxytyrosol Extracted from Olive Leaves: Molecular Docking Simulations of its Antibacterial Mechanisms

This study investigated the biological activities of a hydroxytyrosol-rich extract from Olea europaea leaves, particularly its ability to eradicate severe pathogenic bacteria producing Extended-Spectrum Beta-Lactamases (ESBLs). The latter bacteria are emerging microorganisms that pose significant challenges due to their resistance to a broad range of potent therapeutic drugs. The extract was prepared through an accessible acid hydrolysis method. In vitro and In silico analyses through MIC, MBC analysis and molecular docking were conducted to evaluate the antibacterial properties. The extract showed remarkable antioxidant activity and significant antibacterial potential against reference species and ESBL bacteria. MIC and MBC calculations confirmed the extract's capacity to kill bacteria rather than just inhibit their growth. Further in silico analyzes demonstrated the high binding affinity of HT to the active sites of the gyrase B subunit and the peptidoglycan DD-transpeptidase domain from proteins located in the cytoplasm and the cell wall of the bacteria, respectively. Results confirmed the structure-activity relationship and the ability of HT to disrupt essential bacterial functions. This study validates the debated antimicrobial potential of HT and highlights its importance as a potential therapeutic agent against resistant bacteria, which is a critical area of research given the global challenge of antibiotic resistance.

Phenolic Compounds and Bacteriocins: Mechanisms, Interactions, and Applications in Food Preservation and Safety

Beneficial properties of different natural antimicrobials are topics of scientific curiosity for improving safety and extending the shelf life of food commodities. In this regard, phenolic compounds, natural molecules known for their antioxidant, anti-inflammatory, and antimicrobial properties can be right choice. Moreover, bacteriocins, antimicrobial peptides produced by various microorganisms, capable of inhibiting the growth of other bacteria, particularly closely related species can be genuine alternative. Combining phenolic compounds with bacteriocins can enhance antimicrobial effects, extending the shelf-life of food products by combating spoilage and foodborne pathogens. Despite their potential, the chemical interactions between phenolic compounds and bacteriocins, including synergistic and antagonistic effects, are not well understood. Key areas needing further research include the following: the mechanisms of action against different bacterium types, interactions with cell membranes, enzyme activity, and gene expression; the effects of environmental factors like concentration, pH, temperature, and food matrix specificity on their interactions; and methods for incorporating these compounds into food products and packaging materials to improve food safety. Additionally, the safety, toxicity, allergenicity, sensory properties, nutritional value, regulatory approval, and consumer acceptance of using phenolic compounds and bacteriocins in food products require thorough investigation.

A Comprehensive Review of Antimicrobial Agents Against Clinically Important Bacterial Pathogens: Prospects for Phytochemicals

Antimicrobial resistance (AMR) hinders the effective treatment of a range of bacterial infections, posing a serious threat to public health globally, as it challenges the currently available antimicrobial drugs. Among the various modes of antimicrobial action, antimicrobial agents that act on membranes have the most promising efficacy. However, there are no consolidated reports on the shortcomings of these drugs, existing challenges, or the potential applications of phytochemicals that act on membranes. Therefore, in this review, we have addressed the challenges and focused on various phytochemicals as antimicrobial agents acting on the membranes of clinically important bacterial pathogens. Antibacterial phytochemicals comprise diverse group of agents found in a wide range of plants. These compounds have been found to disrupt cell membranes, inhibit enzymes, interfere with protein synthesis, generate reactive oxygen species, modulate quorum sensing, and inhibit bacterial adhesion, making them promising candidates for the development of novel antibacterial therapies. Recently, polyphenolic compounds have been reported to have proven efficacy against nosocomial multidrug-resistant pathogens. However, more high-quality studies, improved standards, and the adoption of rules and regulations are required to firmly confirm the clinical efficacy of phytochemicals derived from plants. Identifying potential challenges, thrust areas of research, and considering viable approaches is essential for the successful clinical translation of these compounds.

Costa M, Avelar-Gonzalez FJ, Moreno-Flores AC, Vazquez-Pedroza E, Arreola-Guerra JM, González-Gámez M. Guava Leaf Extract Exhibits Antimicrobial Activity in Extensively Drug-Resistant (XDR) Acinetobacter baumannii

Currently, a global health crisis is being caused by microbial resistance, in which Acinetobacter baumannii plays a crucial role, being considered the highest-priority microorganism by the World Health Organization (WHO) for discovering new antibiotics. As a result, phytochemicals have emerged as a potential alternative to combat resistant strains, since they can exert antimicrobial activity through various mechanisms and, at the same time, represent a more natural and safe option. This study analyzes the antimicrobial effects of guava leaf extract in ten clinical isolates of extensively drug-resistant (XDR) A. baumannii, using the agar diffusion technique and the microdilution method to determine the minimum inhibitory concentrations (MICs). Additionally, possible improvements in antimicrobial activity after the purification of polyphenolic compounds and potential synergy with the antibiotic gentamicin are examined in this research. Moreover, the effect of the plant extract in cell line A549 derived from lung tissue was also evaluated. The extract exhibited antimicrobial activity against all the strains studied, and the purification of polyphenols along with the combination with gentamicin improved the extract activity. The presence of the plant extract induced morphological changes in the lung cells after 24 h of exposure. Therefore, Psidium guajava L. leaf extract is a potential antimicrobial agent.

Chemical-functional characterization of Ascophyllum nodosum and Phymatolithon calcareum and dietary supplementation in post-weaning pigs

Introduction

As the livestock industry grapples with the need for sustainable land, maintaining production systems, and reducing antimicrobial resistance, the application of functional nutrition emerges as a potential solution.

Aim

In line with the One Health principles, this study aims to evaluate functional properties of Ascophyllum nodosum and Phymatolithon calcareum, and assess the effects of their dietary supplementation on piglets' health.

Materials and methods

A chemical-functional characterization was conducted before and after in vitro digestion. Total Polyphenols Content (TPC) and Total Flavonoid Content (TFC) were determined through colorimetric assays, while antioxidant activity was determined using ABTS assay, and the microdilution method was used to evaluate the antimicrobial capacity. For the in vivo trial twenty-four post-weaning pigs (28 ± 2 days, 6.89 ± 0.820 Kg) were enrolled in two homogeneous groups (n = 12/group): control group (CTRL) fed a commercial diet, and treated group (ALGAE) fed commercial diet with the addition of 1.5% of A. nodosum and 0.5% of P. calcareum for 27 days. Weekly, zootechnical performances were assessed monitoring the body weight and the individual feed intake. Fecal samples were collected to evaluate the abundance of total, lactic acid and coliform bacteria through plate counting. Serum were obtained at day 0 and day 27 to assess the antioxidant barrier.

Results and discussion

The chemical characterization discloses that the minerals' level remains below the maximum thresholds defined for their use in piglets nutrition. TPC was 330.42 ± 21.372 mg TAE/g of the sample and 11.45 ± 0.521 mg TAE/g of the sample for A. nodosum and P. calcareum, respectively, and a similar trend was found in the TFC evaluation (213.85 ± 20.557 and 2.71 ± 0.900 mg CE/g of sample, respectively). Our results also highlighted that polyphenols and flavonoid compounds persisted after in vitro digestion as well as the functional properties. The administration of algae in piglets diet, although it slightly affected feed efficiency in the first period of the trial, did not affect the animal growth in terms of weight and average daily gain. Microbiological analysis of feces showed similar values between the two experimental groups over 27 days. A significantly higher serum antioxidant barrier was registered in ALGAE compared to CTRL group at day 27 (363.26 ± 16.241 vs. 230.69 ± 32.078 HClO/mL, p < 0.05).

Conclusion

In conclusion, the supplementation with A. nodosum and P. calcareum could be considered a promising dietary strategy to enhance the oxidative barrier in weaned piglets.

Phyto-nutraceutical promise of Brassica vegetables in post-genomic era: a comprehensive review

MAIN CONCLUSION

Brassica vegetables are one of the possible solutions to tackle the emerging human diseases and malnutrition due to their rich content of phyto-nutraceutaical compounds. The genomics enabled tools have facilitated the elucidation of molecular regulation, mapping of genes/QTLs governing nutraceutical compounds, and development of nutrient-rich Brassica vegetables. The enriched food products or foods as whole termed as functional foods are intended to provide health benefits. The 2500 year old Hippocratic phrase 'let thy food be thy medicine and thy medicine be thy food' remained in anonymity due to lack of sufficient evidence. However, today, we are facing reappraisal of healthy nutritious functional foods in battling diseases. In this context, the Brassica vegetables represent the most extensively investigated class of functional foods. An optimal consumption of Brassica vegetables is associated with lowering the risks of several types of cancer, chronic diseases, cardiovascular disease, and help in autism. In the post-genomic era, the integration of genetic and neoteric omics tools like transcriptomics, metabolomics, and proteomics have illuminated the downstream genetic mechanisms governing functional food value of Brassica vegetables. In this review, we have summarized in brief the phyto-nutraceutical profile and their functionality in Brassica vegetables. This review also highlights the progress made in identification of candidate genes/QTLs for accumulation of bioactive compounds in Brassica vegetables. We summarize the molecular regulation of major phytochemicals and breeding triumphs in delivering multifunctional Brassica vegetables.

Chemical composition, antibacterial potential, and toxicity of the extracts from the stem bark of Hancornia speciosa Gomes (Apocynaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Hancornia speciosa is a medicinal plant popularly used to treat different medical issues, including infectious diseases. Exploring the therapeutic potentialities of the extracts from medicinal plants combined with conventional antibiotic drugs is a promising horizon, especially considering the rising microbial resistance.

AIM OF THE STUDY

This study aimed to characterize the chemical composition of the ethereal (EEHS) and methanolic (MEHS) extracts of the stem bark of H. speciosa, and also evaluate their antibacterial and drug-modifying activity, and toxicity.

MATERIALS AND METHODS

The extracts were characterized by gas chromatography coupled to mass spectrometry (GC-MS). Additionally, total phenol and flavonoid contents were determined. The antibacterial and antibiotic-modifying activity was evaluated against strains of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa using the serial microdilution method, obtaining the minimum inhibitory concentration (MIC). The toxicity assay was carried out using the Drosophila melanogaster model.

RESULTS

Thirty compounds were identified in the extracts of the stem bark of H. speciosa, with triterpenoids being predominant in both extracts. Additionally, fatty alcohols, carbohydrates, fatty acids, phenolic acids, and phytosterols were identified in both extracts. EEHS and MEHS extracts had considerable phenol contents (346.4 and 340.0 mg GAE/g, respectively). Flavonoids were detected in a lower proportion (7.6 and 6.9 mg QE/g, respectively). H. speciosa extracts did not display intrinsic antibacterial activity against the bacterial strains evaluated, however, they were capable of modifying the activity of gentamicin, erythromycin, and norfloxacin. EEHS increased the efficacy of norfloxacin against E. coli and S. aureus, reducing MIC values by 50%. MEHS potentiated the action of gentamicin against all bacterial strains, especially against E. coli. The extracts did not display toxicity at clinically relevant concentrations against D. melanogaster.

CONCLUSION

The stem bark of H. speciosa was considered a rich source of bioactive compounds. Our findings evidenced the therapeutic potential of H. speciosa extracts for the development of new pharmaceutical therapeutics against bacteria. Although the extracts did not exhibit intrinsic antibacterial activity, they enhanced the efficacy of commercial antibiotic drugs and were non-toxic at clinically relevant concentrations. Future studies are needed to elucidate the mechanisms of action of these extracts, ensuring their safety and efficacy.

Functionalisation and behaviours of polysaccharides conjugated with phenolic compounds by oxidoreductase catalysis: A review

Polysaccharides have been extensively studied in recent decades. Their conjugation with phenolic compounds of natural origin has demonstrated high added value, not only enhancing certain inherent properties but also introducing new ones. Recently, a sustainable approach utilizing oxidoreductase enzymes (Oxredases) (laccases (Lac), tyrosinases (Tyr) and peroxidases (Per)) has been employed, and interesting progress has been made. This review aims to provide a comprehensive understanding of the various Oxredases employed and the reaction mechanisms involved in the grafting of phenolic compounds (PCs) onto polysaccharides (PSs). We provide a detailed analysis of these reaction mechanisms based on modified polymer structural analysis techniques and supported by model reactions. The impacts of different reaction parameters on the final products are thoroughly discussed. Additionally, the properties of conjugated PS-PC are extensively explored to provide an overview of their physicochemical and functional behaviours. A comparison of the PS-PC conjugates obtained via the Oxredase approach and other existing chemical- and radical-mediated approaches is also presented, emphasizing the benefits of this enzymatic pathway. Finally, a critical analysis is proposed to identify areas of improvement, aiming to further refine this environmentally friendly approach for conjugating PSs and PCs and its scalability for industrial applications.

High acetone soluble organosolv lignin extraction and its application towards green antifouling and wear-resistant coating

Marine fouling poses significant challenges to the efficiency and longevity of marine engineering equipment. To address this issue, developing effective marine antifouling coatings is critical to ensure the economic viability, environmental sustainability, and safety of offshore operations. In this study, we developed an innovative green antifouling and wear-resistant coating based on lignin, a renewable and sustainable resource. Lignin is considered environmentally friendly because it is abundant, biodegradable, and reduces reliance on petroleum-based materials. The coating was formulated with a controlled hydrophilic-to-hydrophobic ratio of 2:8, leveraging lignin's unique properties. Applying lignin increased the water contact angle by 14.5 %, improving surface hydrophobicity and contributing to the coating's antifouling efficacy. Moreover, the mechanical strength of the coating was enhanced by approximately 200 %, significantly boosting its durability in harsh marine environments. Additionally, the friction coefficient was reduced by about 85 %, further preventing organism adhesion. These results demonstrate that lignin-based coatings offer a greener alternative to traditional antifouling solutions. The results of this study not only help advance antifouling coating technology but are also consistent with the broader goal of promoting environmental responsibility in marine engineering practice.

Antioxidant activity of Micractinium sp. (Chlorophyta) extracts against H2O2 induced oxidative stress in human breast adenocarcinoma cells

In response to the growing demand for high-value bioactive compounds, microalgae cultivation has gained a significant acceleration in recent years. Among these compounds, antioxidants have emerged as essential constituents in the food, pharmaceutical, and cosmetics industries. This study focuses on Micractinium sp. ME05, a green microalgal strain previously isolated from hot springs flora in our laboratory. Micractinium sp. cells were extracted using six different solvents, and their antioxidant capacity, as well as total phenolic, flavonoid, and carotenoid contents were evaluated. The methanolic extracts demonstrated the highest antioxidant capacity, measuring 7.72 and 93.80 µmol trolox equivalents g-1 dry weight (DW) according to the DPPH and FRAP assays, respectively. To further characterize the biochemical profile, reverse phase high-performance chromatography (RP-HPLC) was employed to quantify twelve different phenolics, including rutin, gallic acid, benzoic acid, cinnamic acid, and β-carotene, in the microalgal extracts. Notably, the acetone extracts of Micractinium sp. grown mixotrophically contained a high amount of gallic acid (469.21 ± 159.74 µg g-1 DW), while 4-hydroxy benzoic acid (403.93 ± 20.98 µg g-1 DW) was the main phenolic compound in the methanolic extracts under heterotrophic cultivation. Moreover, extracts from Micractinium sp. exhibited remarkable cytoprotective activity by effectively inhibiting hydrogen peroxide-induced oxidative stress and cell death in human breast adenocarcinoma (MCF-7) cells. In conclusion, with its diverse biochemical composition and adaptability to different growth regimens, Micractinium sp. emerges as a robust candidate for mass cultivation in nutraceutical and food applications.

Biochemistry and Future Perspectives of Antibiotic Resistance: An Eye on Active Natural Products

Antibiotic resistance poses a serious threat to the current healthcare system, negatively impacting the effectiveness of many antimicrobial treatments. The situation is exacerbated by the widespread overuse and abuse of available antibiotics, accelerating the evolution of resistance. Thus, there is an urgent need for novel approaches to therapy to overcome established resistance mechanisms. Plants produce molecules capable of inhibiting bacterial growth in various ways, offering promising paths for the development of alternative antibiotic medicine. This review emphasizes the necessity of research efforts on plant-derived chemicals in the hopes of finding and creating novel drugs that can successfully target resistant bacterial populations. Investigating these natural chemicals allows us to improve our knowledge of novel antimicrobial pathways and also expands our antibacterial repertoire with novel molecules. Simultaneously, it is still necessary to utilize present antibiotics sparingly; prudent prescribing practices must be encouraged to extend the effectiveness of current medications. The combination of innovative drug research and responsible drug usage offers an integrated strategy for managing the antibiotic resistance challenge.

Prospecting Pharmacologically Active Biocompounds from the Amazon Rainforest: In Vitro Approaches, Mechanisms of Action Based on Chemical Structure, and Perspectives on Human Therapeutic Use

The Amazon rainforest is an important reservoir of biodiversity, offering vast potential for the discovery of new bioactive compounds from plants. In vitro studies allow for the investigation of biological processes and interventions in a controlled manner, making them fundamental for pharmacological and biotechnological research. These approaches are faster and less costly than in vivo studies, providing standardized conditions that enhance the reproducibility and precision of data. However, in vitro methods have limitations, including the inability to fully replicate the complexity of a living organism and the absence of a complete physiological context. Translating results to in vivo models is not always straightforward, due to differences in pharmacokinetics and biological interactions. In this context, the aim of this literature review is to assess the advantages and disadvantages of in vitro approaches in the search for new drugs from the Amazon, identifying the challenges and limitations associated with these methods and comparing them with in vivo testing. Thus, bioprospecting in the Amazon involves evaluating plant extracts through bioassays to investigate pharmacological, antimicrobial, and anticancer activities. Phenolic compounds and terpenes are frequently identified as the main bioactive agents, exhibiting antioxidant, anti-inflammatory, and antineoplastic activities. Chemical characterization, molecular modifications, and the development of delivery systems, such as nanoparticles, are highlighted to improve therapeutic efficacy. Therefore, the Amazon rainforest offers great potential for the discovery of new drugs; however, significant challenges, such as the standardization of extraction methods and the need for in vivo studies and clinical trials, must be overcome for these compounds to become viable medications.

Rosmarinic Acid Exhibits Antifungal and Antibiofilm Activities Against Candida albicans: Insights into Gene Expression and Morphological Changes

Candida species, opportunistic pathogens that cause various infections, pose a significant threat due to their ability to form biofilms that resist antifungal treatments and immune responses. The increasing resistance of Candida spp. and the limited availability of effective treatments have prompted the research of natural compounds as alternative therapies. This study assessed the antifungal properties of RA against Candida species, focusing on its impact on C. albicans biofilms and the underlying mechanisms. The antifungal efficacy of RA was evaluated using the CLSI M27-A3 microdilution method on both fluconazole-susceptible and -resistant strains. Biofilm formation by C. albicans was assessed through a crystal violet assay, while its antibiofilm activity was analyzed using an MTT assay and field emission scanning electron microscopy (FESEM). Gene expression related to biofilm formation was studied using quantitative real-time PCR (qRT-PCR), and statistical analysis was performed with an ANOVA. Among the 28 Candida strains tested, RA exhibited minimum inhibitory concentration (MIC) values ranging from 160 to 1280 μg/mL. At a 640 μg/mL concentration, it significantly reduced the expression of genes associated with adhesion (ALS3, HWP1, and ECE1), hyphal development (UME6 and HGC1), and hyphal cAMP-dependent protein kinase regulators (CYR1, RAS1, and EFG1) in RAS1-cAMP-EFG1 pathway (p < 0.05). FESEM analysis revealed a reduction in hyphal networks and disruptions on the cell surface. Our study is the first to demonstrate the effects of RA on C. albicans adhesion, hyphae development, and biofilm formation through gene expression analysis with findings supported by FESEM. This approach distinguishes our study from previous studies on the effect of RA on Candida. However, the high MIC values of RA limit its antifungal potential. Therefore, more extensive research using innovative methods is required to increase the antifungal effect of RA.

Fish oil-containing edible films with active film incorporated with extract of Psidium guajava leaves: preparation and characterization of double-layered edible film

The utilization of zein and gum arabic has grown in an attempt to formulate wall materials based on protein-polysaccharide complexes. This mixture provides a versatile delivery system for hydrophilic (guava leaf extract, GLE) or lipophilic (fish oil, FO) bioactive compounds, and it can be used as an edible film-forming polymer. This study was undertaken to characterize FO-containing edible films that were double-layered with a film containing GLE. Modified zein and gum arabic solutions (MG complex) were mixed at a ratio of 1:1.5 (v/v), adjusted to pH 5, added with glycerol (20% of the complex) and FO (5% of the complex), and finally adjusted to pH 5. This was prepared as the bottom/lower layer. The upper/active layer was prepared by mixing MG complex, glycerol, and GLE (1, 3, and 5% w/v of the complex). The total phenolic and flavonoid contents in GLE were 15.81 mg GAE/g extract and 6.99 mg QE/g extract, respectively. The IC50 of the DPPH radical scavenging activity of GLE was 26.86 ppm with antibacterial activity against Bacillus subtilis and Escherichia coli of 9.83 and 12.55 mm. The total plate counts of double-layered films containing GLE were retained below 3 log CFU/g during 28-day storage. The peroxide values of these films were dimmed for no more than 9.08 meq/kg sample on day 28 of storage. Thickness (872.00-971.67 μm), water vapor transmission rate (12.99-17.04 g/m 2/day), tensile strength (1.56-2.02 kPa), elongation at break (61.53-75.41%), glass transition (52.74-57.50°C), melting peak (131.59-142.35°C), inhibition against B. subtilis (33.67-40.58 mm), and inhibition against E. coli (2.05-9.04 mm) were obtained by double-layered films. GLE can be successfully incorporated into the active layer of a double-layer film to improve its characteristics while significantly slowing down the microbial contamination and oxidation rate. MG complex and FO can also contribute to the performance of the edible film.

An introduction to antibacterial materials in composite restorations

The longevity of direct esthetic restorations is severely compromised because of, among other things, a loss of function that comes from their susceptibility to biofilm-mediated secondary caries, with Streptococcus mutans being the most prevalent associated pathogen. Strategies to combat biofilms range from dental compounds that can disrupt multispecies biofilms in the oral cavity to approaches that specifically target caries-causing bacteria such as S mutans. One strategy is to include those antibacterial compounds directly in the material so they can be available long-term in the oral cavity and localized at the margin of the restorations, in which many of the failures initiate. Many antibacterial compounds have already been proposed for use in dental materials, including but not limited to phenolic compounds, antimicrobial peptides, quaternary ammonium compounds, and nanoparticles. In general, the goal of incorporating them directly into the material is to increase their availability in the oral cavity past the fleeting effect they would otherwise have in mouth rinses. This review focuses specifically on natural compounds, of which polyphenols are the most abundant category. The authors examined attempts at using these either as pretreatment or incorporated directly into restorative material as a step toward fulfilling a long-recognized need for restorations that can combat or prevent secondary caries formation. Repeatedly restoring failed restorations comes with the loss of more tooth structure along with increasingly complex and costly dental procedures, which is detrimental to not only oral health but also systemic health.

Investigating the Antibacterial Effect of a Novel Gallic Acid-Based Green Sanitizer Formulation

The purpose of the present study was to investigate the mechanism of action of our newly developed green sanitizer formulation comprising a natural phenolic compound, gallic acid (GA), strengthened by the Generally Recognized as Safe (GRAS) materials hydrogen peroxide (H2O2) and DL-lactic acid (LA). Combining 8 mM GA with 1 mM H2O2 resulted in an abundant generation of reactive oxygen species (ROS) and a bactericidal effect towards Gram-negative (Escherichia coli, Pseudomonas syringae, and Pectobacterium brasiliense) and Gram-positive (Bacillus subtilis) bacteria (4 to 8 log CFU mL-1 reduction). However, the exposure to this dual formulation (DF) caused only a modest 0.7 log CFU mL-1 reduction in the Gram-positive L. innocua population. Amending the DF with 20 mM LA to yield a triple formulation (TF) resulted in the efficient synergistic control of L. innocua proliferation without increasing ROS production. Despite the inability to grow on plates (>7 log CFU mL-1 population reduction), the TF-exposed L. innocua maintained high intracellular ATP pools and stable membrane integrity. The response of L. innocua to TF could be qualified as a "viable but nonculturable" (VBNC) phenomenon, while with the other species tested this formulation caused cell death. This research system may offer a platform for exploring the VBNC phenomenon, a critical food safety topic.

Unveiling the phytochemical profile, antioxidant and antibacterial activities, acute toxicity insight and analgesic effect of Retama dasycarpa stems: An unexplored endemic plant from Morocco

Retama dasycarpa is an endemic shrubby leguminous plant of Morocco used in traditional folk medicine. The plant has never been studied for either its phytochemical or pharmacological properties. This study represents the first investigation of the phytochemical profile as well as the antioxidant, the antibacterial, the analgesic effects and the oral acute toxicity of Retama dasycarpa. Watery and hydromethanolic stems plant macerates have been investigated. Secondary metabolites quantitative analysis was achieved through spectrophotometric techniques. Antioxidant effect was explored through DPPH, ABTS and FRAP trials. Antibacterial activity was investigated using a micro-plates dilution assay. Analgesic activity was explored through acetic acid-induced writhing and tail-flick methods. Acute oral toxicity was investigated on mice. Phytochemical analysis was achieved through UHPLC connected to diode array and mass spectrometry detectors. The obtained results showed significant contents in total phenolics, flavonoids and tannins in both extracts especially the hydromethanolic extract whose contents were slighlty higher than the aqueous one resulting in a remarkable antioxidant activity. Compared to the aqueous extract, the H2O:MeOH (1:1) one showed notable antibacterial activity against the tested strains. The acute toxicity in mice revealed the non-toxicity of the extracts along with a promised starting material of central and peripheral analgesics. The UHPLC analysis revealed the presence of several bioactive phytochemicals pertaining to phenolic acids, flavonols, flavones and isoflavones. The obtained results demonstrate the richness of this endemic and unexplored plant in terms of bioactive compounds and their associated activities, making it a promising source of pharmacological ingredients.

Cryptophytes as potential source of natural antimicrobials for food preservation

Cryptophytes are a promising source of bioactive compounds that have not been fully explored. This research investigated the antimicrobial activity of total phenolic compounds (TPC) and exopolysaccharides (EPS) extracted from several cryptophytes against a range of harmful foodborne bacteria and fungi. To measure the minimum inhibitory concentration (MIC) value, the broth microdilution method was used. In the antibacterial evaluation of TPC, the MIC ranged between 31.25 and 500 μg/mL, while for the antifungal activity test, it varied from 31.25 to 125 μg/mL. In the antibacterial activity test of EPS, the MIC values ranged from 125 to 1,000 μg/mL, whereas in the antifungal susceptibility test, it ranged between 62.5 and 1,000 μg/mL. The most resistant pathogen against TPC was Escherichia coli, while Campylobacter jejuni was the most susceptible. In the case of EPS, the most resistant pathogen was Salmonella Typhimurium, while Aspergillus versicolor exhibited the highest susceptibility. Overall, in terms of antimicrobial activity, TPC was more effective than EPS. Finally, the tolerance level (TL) for TPC and EPS was ≤4 in all tested samples, indicating their bactericidal/fungicidal mechanism of action. In conclusion, TPC and EPS isolated from cryptophytes demonstrated remarkable antimicrobial properties and ability to fully eradicate pathogens, and could be considered as natural preservatives in the food industry.

Insight into Romanian Wild-Grown Heracleum sphondylium: Development of a New Phytocarrier Based on Silver Nanoparticles with Antioxidant, Antimicrobial and Cytotoxicity Potential

Background: Heracleum sphondylium, a medicinal plant used in Romanian ethnopharmacology, has been proven to have remarkable biological activity. The escalating concerns surrounding antimicrobial resistance led to a special attention being paid to new efficient antimicrobial agents based on medicinal plants and nanotechnology. We report the preparation of a novel, simple phytocarrier that harnesses the bioactive properties of H. sphondylium and silver nanoparticles (HS-Ag system). Methods: H. sphondylium's low metabolic profile was determined through gas chromatography-mass spectrometry and electrospray ionization-quadrupole time-of-flight-mass spectrometry. The morphostructural properties of the innovative phytocarrier were analyzed by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, dynamic light scattering, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The antioxidant activity was evaluated using total phenolic content, ferric reducing antioxidant power, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro assays. The antimicrobial activity screening against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli was conducted using the agar well diffusion method. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay estimated the in vitro potential cytotoxicity on normal human dermal fibroblasts (NHDF) and cervical cancer (HeLa) cells. Results: A total of 88 biomolecules were detected, such as terpenoids, flavonoids, phenolic acids, coumarins, phenylpropanoids, iridoids, amino acids, phytosterols, fatty acids. The HS-Ag phytocarrier heightened efficacy in suppressing the growth of all tested bacterial strains compared to H. sphondylium and exhibited a significant inhibition of HeLa cell viability. Conclusions: The new HS-Ag phytocarrier system holds promise for a wide range of medical applications. The data confirm the capacity to augment the pertinent theoretical understanding in the innovative field of antimicrobial agents.

Recent Development of Functional Bio-Based Epoxy Resins

The development of epoxy resins is mainly dependent on non-renewable petroleum resources, commonly diglycidyl ether bisphenol A (DGEBA)-type epoxy monomers. Most raw materials of these thermoset resins are toxic to the health of human beings. To alleviate concerns about the environment and health, the design and synthesis of bio-based epoxy resins using biomass as raw materials have been widely studied in recent decades to replace petroleum-based epoxy resins. With the improvement in the requirements for the performance of bio-based epoxy resins, the design of bio-based epoxy resins with unique functions has attracted a lot of attention, and bio-based epoxy resins with flame-retardant, recyclable/degradable/reprocessable, antibacterial, and other functional bio-based epoxy resins have been developed to expand the applications of epoxy resins and improve their competitiveness. This review summarizes the research progress of functional bio-based epoxy resins in recent years. First, bio-based epoxy resins were classified according to their unique function, and synthesis strategies of functional bio-based epoxy resins were discussed, then the relationship between structure and performance was revealed to guide the synthesis of functional bio-based epoxy resins and stimulate the development of more types of functional bio-based epoxy resins. Finally, the challenges and opportunities in the development of functional bio-based epoxy resins are presented.

Assessment of the antibacterial and antioxidant activities of seaweed-derived extracts

In swine farming, animals develop diseases that require the use of antibiotics. In-feed antibiotics as growth promoters have been banned due to the increasing concern of antimicrobial resistance. Seaweeds offer bioactive molecules with antibacterial and antioxidant properties. The aim was to estimate the in vitro properties of seaweed extracts: Ascophyllum nodosum (AN), Palmaria palmata (PP), Ulva lactuca (UL), and 1:1 mixes (ANPP, ANUL, PPUL). Escherichia coli strains were used to test for growth inhibitory activity, and chemical-based assays were performed for antioxidant properties. The treatments were 2 (with/without Escherichia coli) × 2 (F4 + and F18 +) × 5 doses (0, 1.44, 2.87, 5.75, 11.50, and 23.0 mg/mL). Bacteria were supplemented with seaweed extracts, and growth was monitored. The antioxidant activity was assessed with 6 doses (0, 1, 50, 100, 200, 500, and 600 mg/mL) × 6 compounds using two chemical assays. Data were evaluated through SAS. The results showed that AN and UL significantly inhibited (p < 0.05) the growth of F4 + and F18 +. PP and mixes did not display an inhibition of the bacteria growth. AN, PP, UL extracts, and mixes exhibited antioxidant activities, with AN showing the strongest dose-response. Thus, AN and UL seaweed extracts reveal promising antibacterial and antioxidant effects and may be candidates for in-feed additives.

Hierarchical Chitin Nanocrystal-Based 3D Printed Dual-Layer Membranes Hydrogels: A Dual Drug Delivery Nano-Platform for Periodontal Tissue Regeneration

Periodontitis, a prevalent chronic inflammatory disease caused by bacteria, poses a significant challenge to current treatments by merely slowing their progression. Herein, we propose an innovative solution in the form of hierarchical nanostructured 3D printed bilayer membranes that serve as dual-drug delivery nanoplatforms and provide scaffold function for the regeneration of periodontal tissue. Nanocomposite hydrogels were prepared by combining lipid nanoparticle-loaded grape seed extract and simvastatin, as well as chitin nanocrystals, which were then 3D printed into a bilayer membrane that possesses antimicrobial properties and multiscale porosity for periodontal tissue regeneration. The constructs exhibited excellent mechanical properties by adding chitin nanocrystals and provided a sustained release of distinct drugs over 24 days. We demonstrated that the bilayer membranes are cytocompatible and have the ability to induce bone-forming markers in human mesenchymal stem cells, while showing potent antibacterial activity against pathogens associated with periodontitis. In vivo studies further confirmed the efficacy of bilayer membranes in enhancing alveolar bone regeneration and reducing inflammation in a periodontal defect model. This approach suggests promising avenues for the development of implantable constructs that not only combat infections, but also promote the regeneration of periodontal tissue, providing valuable insights into advanced periodontitis treatment strategies.

Pinhão potential and their parts (failures, shells, and almonds) in the elaboration of yogurts containing acai pulp: physicochemical, nutritional, and functional properties, antimicrobial activity, and multi-elemental profile

This study applies natural resources, prioritizing recyclable and renewable inputs produced by pinhão cultivation, whose purpose is to use the failures, shells, and almonds as a source of bioactive compounds addition in yogurt, ensuring intelligent use of these natural resources. Thus, one açaí yogurt sample and eight yogurt formulations containing portions of pinhão byproducts between 5 % and 10 % were elaborated. These formulations were compared regarding their physicochemical, nutritional, functional properties, antimicrobial activity, and multi-elemental profile properties. Enriching açaí yogurt with pinhão byproducts does not significantly differ in protein, lipid, moisture, and mineral salt content between all samples with pinhão byproducts. Açaí yogurts enriched with pinhão byproducts had 5.71 to 26.07 % times total protein than the control sample, and total fiber also had a significant increase in samples ranging between 18.62 to 85.29 % times more than the control sample. Regarding color settings, all yogurt samples tended to be red-purple. A sample of açaí yogurt with pine nut flour and whole pine nut flour caused a biofilm mass amount of 46.58, 45.55, and 11.85 % for Listeria monocytogenes, Salmonella enteritidis and Pseudomonas aeruginosa. The behavior of pathogenic bacteria is related to the total polyphenol content in yogurts enriched with pinhão byproducts, which increased from 8.27 to 18.24 mg/100 g. Yogurt with açaí enriched with whole pinhão flour showed high antioxidant capacity. The sample's antioxidant activity results increased by 47.62 % and 130.38 % in the ABTS and DPPH analyses, respectively. The compounds in pinhão failure nanosuspensions, pinhão flour, whole pinhão flour, and yogurts were identified and divided into hydrophilic and lipophilic classes. Five classes (amino acids, organic acids, sugars, phenols, and cyclitols) were identified as hydrophilic. Lipophilic compounds were identified and separated into six classes (carboxylic acids, diterpenes, alcohols, Α-hydroxy acids, sterols, and triterpenes). The addition of pinhão byproducts increased the contents of Ca, Fe, K, Na, and P. Açaí yogurt with pinhão nanosuspension, pinhão flour, and whole pinhão flour had the highest Ca content (2164.38 ± 2.16 µg/L). Açaí yogurt with pinhão flour and whole pinhão flour had the highest Fe content (84.02 ± 0.08 µg/L).

Bio-Based Thermosetting Resins: From Molecular Engineering to Intrinsically Multifunctional Customization

Recent years have witnessed a growing interest in bio-based thermosetting resins in terms of environmental concerns and the desire for sustainable industrial practices. Beyond sustainability, utilizing the structural diversity of renewable feedstock to craft bio-based thermosets with customized functionalities is very worthy of expectation. There exist many bio-based compounds with inherently unique chemical structures and functions, some of which are even difficult to synthesize artificially. Over the past decade, great efforts are devoted to discovering/designing functional properties of bio-based thermosets, and notable progress have been made in antibacterial, antifouling, flame retardancy, serving as carbon precursors, and stimuli responsiveness, among others, largely expanding their application potential and future prospects. In this review, recent advances in the field of functional bio-based thermosets are presented, with a particular focus on molecular structures and design strategies for discovering functional properties. Examples are highlighted wherein functionalities are facilitated by the inherent structures of bio-based feedstock. Perspectives on issues regarding further advances in this field are proposed at the end.

Assessment of antibacterial activity, modes of action, and synergistic effects of Origanum vulgare hydroethanolic extract with antibiotics against avian pathogenic Escherichia coli

This study evaluates the antibacterial effectiveness of Origanum vulgare hydroethanolic extract, both independently and in combination with antibiotics, against Escherichia coli strains associated with avian colibacillosis-a significant concern for the poultry industry due to the rise of antibiotic-resistant E. coli. The urgent demand for new treatments is addressed by analyzing the extract's phytochemical makeup via High-Performance Liquid Chromatography (HPLC), which identified sixteen phenolic compounds. Antibacterial activity was determined through agar diffusion and the measurement of minimum inhibitory and bactericidal concentrations (MIC and MBC), showing moderate efficacy (MIC: 3.9 to 7.8 mg/mL, MBC: 31.2 to 62.4 mg/mL). Combining the extract with antibiotics like ampicillin and tetracycline amplified antibacterial activity, indicating a synergistic effect and highlighting the importance of combinatory treatments against resistant strains. Further analysis revealed the extract's mechanisms of action include disrupting bacterial cell membrane integrity and inhibiting ATPase/H+ proton pumps, essential for bacterial survival. Moreover, the extract effectively inhibited and eradicated biofilms, crucial for preventing bacterial colonization. Regarding cytotoxicity, the extract showed no hemolytic effect at 1 to 9 mg/mL concentrations. These results suggest Origanum vulgare extract, particularly when used with antibiotics, offers a promising strategy for managing avian colibacillosis, providing both direct antibacterial benefits and moderating antibiotic resistance, thus potentially reducing the economic impact of the disease on the poultry industry.

Aerobic phenol degradation using native bacterial consortium via ortho-and meta-cleavage pathways

Effective bioremediation of a phenol-polluted environment harnesses microorganisms' ability to utilize hazardous compounds as beneficial degraders. In the present study, a consortium consisting of 15 bacterial strains was utilized. The current study aims to monitor the phenol biodegradation pathway. The tested consortium showed effective potential in the bioremediation of phenol-contaminated industrial wastewater. The enzymatic studies conducted brought to light that the bacterial consortium under test was proficient in degrading phenol under aerobic conditions while exhibiting the simultaneous expression of both ortho- and meta-cleavage pathways. It was observed that pheA, pheB, and C12O genes were maximally expressed, and the enzymes responsible for phenol degradation, namely, phenol hydroxylase, catechol 1,2-dioxygenase, and catechol 2,3-dioxygenase, reached maximum activity after 48 h of incubation with a 20-ppm phenol concentration. To gain a deeper understanding of the activation of both ortho- and meta-cleavage pathways involved in phenol degradation, a technique known as differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) was applied. This method allowed for the specific amplification and detection of genes responsible for phenol degradation. The expression levels of these genes determined the extent to which both ortho- and meta-cleavage pathways were activated in response to the presence of phenol.