Tannins as an alternative to antibiotics

Cashew Apple Pomace: Chemical Composition and Applications in Functional Food Product Development-A Review

Cashew nut production and fruit processing generate significant by-products, particularly cashew apple and cashew apple pomace (CAP), which are often treated as waste. However, CAP is a valuable source of nutrients and bioactive compounds that can be repurposed to develop functional food products. Valorizing this by-product represents a pivotal advancement toward achieving sustainability and circularity in the food industry. This review aimed to highlight the chemical composition and potential applications of CAP in functional food development. The review shows that CAP is enriched with bioactive compounds, including phenolic acids, carotenoids, and flavonoids, alongside essential nutrients such as fiber, minerals, carbohydrates, and proteins. The incorporation of CAP into food products may confer a myriad of health benefits, including antioxidant, antimicrobial, antidiabetic, antiobesity, and gastroprotective properties. This review elucidates approaches to effectively integrate CAP into food formulations while preserving their sensory attributes. Utilizing CAP in food products can significantly reduce food waste and enhance the overall nutritional and functional profile of food, contributing to a more sustainable and circular food system.

Deep eutectic solvent extraction of polyphenol from plant materials: Current status and future prospects in food applications

The increasing environmental concerns related to biomass waste have led to the exploration of sustainable methods for extracting bioactive compounds from plant materials, especially polyphenols, which are valued for their health benefits and use in functional foods and natural additives. These bioactive compounds are abundant in fruits, vegetables, tea, and herbs, and encompass flavonoids, phenolic acids, tannins, stilbenes, and lignans. Traditional extraction methods often rely on harmful petrochemical solvents, which pose significant environmental and health risks. In contrast, Deep Eutectic Solvents (DESs) have emerged as an eco-friendly alternative, offering advantages such as low toxicity, cost-efficiency, and a wide range of solubility. This review focused recent advancements in DES-based polyphenol extraction, emphasizing their applications in the food industry. It highlights the potential of DES to efficiently extract polyphenols, improving their bioavailability and stability, and exploring future prospect for enhancing food quality, safety, and functionality through functional foods and natural preservatives.

Antilisterial activity of tannin rich preparations isolated from raspberry (Rubus Idaeus L.) and strawberry (Fragaria X Ananassa Duch.) fruit

The tannin rich preparations isolated from red raspberry (Rubus idaeus L.) and strawberry (Fragaria x ananassa Duch.) fruits were evaluated for their polyphenol composition and antimicrobial activity against six strains of Listeria monocytogenes, sourced from the ATCC collection. The preparations were obtained using solvent extraction with a water-acetone solution, followed by purification using Amberlite XAD 1600 resin. The resulting products, RTRP (raspberry tannin rich preparation) and STRP (strawberry tannin rich preparation), were characterized by their content of ellagitannins, proanthocyanidins, and anthocyanins. Polyphenol content was determined using HPLC-FD and UHPLC-DAD-MS with QExactive mass spectrometer. The antagonistic activity of the preparations against Listeria spp. strains was assessed using the disk diffusion method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by dilution techniques. The RTRP and STRP exhibited tannin contents of 74 g/100 g and 47 g/100 g, respectively. In the raspberry preparation, ellagitannins were dominant, while in the strawberry preparation, ellagitannins and proanthocyanidins were present at similar levels. In the general antagonism test at a concentration of 60 mg/mL, inhibition zones for L. monocytogenes ranged from 10.0 to 24.5 mm. The MIC values for the preparations ranged from 1.563 to 25 mg/mL, varying depending on the tested strains. Based on MIC and MBC, L. monocytogenes ATCC 19,111 was the most sensitive to the preparations, whereas ATCC 15,313 exhibited the greatest resistance. Despite their different tannin profiles, the preparations generally did not show statistically significant differences in their antilisterial activity. The results indicate that the tannin rich preparations from red raspberry and strawberry fruits exhibit moderate antilisterial activity, dependent on the sensitivity of the specific L. monocytogenes strain tested.

Eco-friendly coating fabricated by quaternary chitosan/tannins assembly coupled with DOPO towards fabricating multifunctional PA66 fabrics

Polyamide 66 (PA66) fabric has attracted significant attention due to its excellent overall performance. However, its flammability and melt droplet defects severely restricted its wide application. In this work, we successfully developed a bio-based multifunctional intumescent flame retardant (MIFR) coating for PA66 fabric via the interactions between quaternary chitosan (QC), tannins (TA), 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and 4-Formylphenylboronic acid (4-FB). The results indicated that the coated polyamide 66 (PA66) fabric (P-PA66@TA@QC) achieved a limiting oxygen index (LOI) of 30.1 % and no molten droplets generated during the combustion. Additionally, the peak heat release rate (pHRR) and total heat release rate (THR) of P-PA66@TA@QC were reduced by 50.3 % and 55.7 %, while the total smoke production (TSP) was decreased by 80 % compared to the control sample, exhibiting a lower fire risk and excellent smoke suppression performances. Furthermore, P-PA66@TA@QC exhibited good hydrophilicity, high UV protection factor (UPF > 180), and high inhibition rate against E. coli (> 99.9 %) and S. aureus (> 99.9 %), indicating outstanding UV resistance and excellent antibacterial properties. This study successfully developed a bio-based multifunctional flame retardant coating, providing significant guidance for preparing eco-friendly and multifunctional PA66 fabrics.

Therapeutic potential and limitation of condensed and hydrolyzed tannins in Parkinson's disease

Parkinson's disease is a complex neurodegenerative disorder characterized by neuroinflammation, mitochondrial dysfunction, and the accumulation of misfolded proteins such as α-synuclein. This review explores the therapeutic potential of tannins, particularly proanthocyanidins and hydrolyzable tannins from grape seeds, in alleviating Parkinson's disease pathology. Condensed tannins exhibit significant antioxidant properties, can cross the blood-brain barrier, reduce oxidative stress, upregulate antioxidant proteins, and prevent neuronal apoptosis. Hydrolyzable tannins, through their unique chemical structure, further help reduce neuroinflammation and improve mitochondrial function. Both types of tannins can modulate inflammatory responses and enhance mitochondrial integrity, addressing key aspects of Parkinson's disease pathogenesis. Tannins possess excellent neuroprotective effects, representing a promising therapeutic approach. However, due to their chemical nature and structural characteristics, the bioavailability of tannins in the human body remains low. Current methods to enhance their bioavailability are limited. Further exploration is needed to improve their bioavailability and strengthen their potential clinical applications. Based on this, new Parkinson's disease treatment strategies can be developed, warranting in-depth research and clinical validation.

Fabrication of multifunctional hydrogels based on tannic acid-coated nanocrystalline cellulose

Composite hydrogels are promising for wound healing, but combining strong antimicrobial properties with mechanical performance remains challenging due to potential disruptions in cross-linking. This study presented a one-step method to incorporate tannic acid-coated cellulose nanocrystals (TA@CNC) into polyacrylamide hydrogels. The resulting composite hydrogel exhibited superior mechanical strength, environmental stability, and antimicrobial and antioxidant activities. TA@CNC served as a dynamic reinforcement within the porous network, enhancing mechanical stability. The hydrogel also demonstrated sustained and repeatable adhesion, attributed to the moisture-resistant properties of tannic acid. This work offers valuable insights for the design of multifunctional composite hydrogels, with the developed materials showing great potential for use in medical dressings due to their stretchability, self-adhesion, and antimicrobial and antioxidant properties.

Antimicrobial Potential of Chitosan Films Incorporated with Alcoholic Extract from Mimosa tenuiflora Leaves

Antimicrobial films were prepared with chitosan containing the methanolic extract of M. tenuiflora leaves (FECT20 %, FECT30 %, and FECT40 %), and their antimicrobial activities were evaluated by agar diffusion. The films were characterized by IR spectroscopy, scanning electron microscopy (SEM) and TG/DTG curves. TG/DTG curves showed thermal stability of chitosan-extract films up to 166 °C. Micrographs of chitosan-extract films revealed an increase in porosity with the addition of extract. The FECT40 % film showed inhibition zone diameters (IZ) against Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis, and B. cereus, ranging from 1.0±0.02 to 0.72±0.09 cm. Only FECT30 % and FECT40 % inhibited the P. aeruginosa with IZs of 0.68±0.02 and 0.77±0.06 cm, respectively. In turn, the extract showed inhibition against B. subtilis and B. cereus, with IZs values of 0.92±0.2 cm and 0.72±0.05 cm, respectively. Additionally, the crude extract presented antioxidant potential with inhibition percentages of 32.74 %±0.90 for ABTS and 27.04 %±1.36 for DPPH. The antimicrobial and antioxidant activities of the crude extract, as well as the antimicrobial property of chitosan-extract films, suggests the potential of these biopolymers for the development of wound healing bandages and new food packaging alternatives.

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.

Antimicrobial Potential of Polyphenols: Mechanisms of Action and Microbial Responses-A Narrative Review

Polyphenols (PPs) are recognized as bioactive compounds and antimicrobial agents, playing a critical role in enhancing food safety, preservation, and extending shelf life. The antimicrobial effectiveness of PPs has different molecular and biological reasons, predominantly linked to their hydroxyl groups and electron delocalization, which interact with microbial cell membranes, proteins, and organelles. These interactions may reduce the efficiency of metabolic pathways, cause destructive damage to the cell membrane, or they may harm the proteins and nucleic acids of the foodborne bacteria. Moreover, PPs exhibit a distinctive ability to form complexes with metal ions, further amplifying their antimicrobial activity. This narrative review explores the complex and multifaceted interactions between PPs and foodborne pathogens, underlying the correlation of their chemical structures and mechanisms of action. Such insights shed light on the potential of PPs as innovative natural preservatives within food systems, presenting an eco-friendly and sustainable alternative to synthetic additives.

A Comprehensive Review of Bioactive Tannins in Foods and Beverages: Functional Properties, Health Benefits, and Sensory Qualities

Tannins, a diverse class of polyphenolic compounds, are widely present in a variety of plant-based foods and beverages, where they contribute significantly to flavor, astringency, and numerous health benefits. Known for their antioxidant, anti-inflammatory, and cardioprotective properties, tannins are associated with a reduced risk of chronic diseases such as cardiovascular disease, cancer, and diabetes. Their bioavailability and metabolism are influenced by factors such as polymerization, solubility, and interactions with the gut microbiota. Tannin-rich beverages, including tea, wine, fruit juices, and cider, offer a range of health-promoting effects, including antioxidant, cardioprotective, and antimicrobial activities. In addition, tannins contribute significantly to the sensory and nutritional characteristics of fruits, nuts, and vegetables, influencing flavor, color, and nutrient absorption. The levels and efficacy of tannins are subject to variation due to factors such as ripeness and food processing methods, which can increase their impact on food quality and health. This review provides a comprehensive examination of the bioactive roles of tannins, their nutritional implications, and their sensory effects, highlighting their importance in both dietary applications and overall well-being.

Optimization of Haskap Extract and Tannic Acid Combined with Mild Heat Treatment: A Predictive Study on the Inhibition of Cronobacter sakazakii

Cronobacter sakazakii is an opportunistic food-borne pathogen that causes severe infections with high morbidity and mortality rates in neonates, the elderly, and immunocompromised individuals. The plant extracts containing natural antibacterial compounds are currently under consideration as alternatives to synthetic artificial preservatives for the control of C. sakazakii. There has been increasing interest in using plant-derived antimicrobials in combination with mild heat to control pathogens in preservative-free foods. In this study, the individual and combined effects of four independent variables, i.e., polyphenol-rich haskap extract (HE) concentration (2-10%), tannic acid (TA) concentration (0.1-0.5), temperature (35-55 °C), and time (1-5 min), on C. sakazakii inactivation were investigated by response surface methodology (RSM) with a five-level four factor central composite design (CCD) and an optimal combination for maximum inhibition was determined. The statistic metrics of R2, R2adjusted, R2predicted, coefficient of variation (CV), Predicted Residual Error Sum of Squares (PRESSs), adequate precision, and lack-of-fit were used to reveal the prediction performance. The results revealed that all the independent variables, except time, influenced C. sakazakii inactivation. Among the independent variables, the temperature was the most effective variable (p < 0.0001) as regards inactivation. The synergistic effects of HE with TA and temperature were observed. Many possible optimum conditions of mild heat treatment that maximized the inhibition of C. sakazakii were obtained. The findings indicated that two distinct combinations were identified as the most effective inhibition of C. sakazakii: high concentration at low temperature and high temperature at low concentration. It can be concluded that haskap polyphenol extract, alone or in combination with tannic acid, has the potential to be used as a natural preservative to reduce the risk of C. sakazakii.

Unravelling the potential of natural chelating agents in the control of Staphylococcus aureus and Pseudomonas aeruginosa biofilms

Iron is essential for the formation, maturation and dispersal of bacterial biofilms, playing a crucial role in the physiological and metabolic functions of bacteria as well as in the regulation of virulence. Limited availability of iron can impair the formation of robust biofilms by altering cellular motility, hydrophobicity and protein composition of the bacterial surface. In this study, the antibiofilm activity of two natural iron chelating agents, kojic acid (5-hydroxy-2-hydroxymethyl-4H-pyran-4-one) and maltol (3-hydroxy-2-methyl-4-pyrone), were investigated against Staphylococcus aureus and Pseudomonas aeruginosa. In addition, the ability of these 2-hydroxy-4-pyrone derivatives in preventing and eradicating S. aureus and P. aeruginosa biofilms through the enhancement of the efficacy of two antibiotics (tobramycin and ciprofloxacin) was explored. The iron binding capacity of the kojic acid and maltol was confirmed by their affinity for iron (III) which was found to be about 90 %, comparable to the regular chelating agent ethylenediaminetetraacetic acid (EDTA, 89 %). The antibiofilm efficacy of 2-hydroxy-4-pyrone derivatives, alone and in combination with antibiotics, was evaluated by measuring the total biomass, metabolic activity, and culturability of biofilm cells. Furthermore, their impact on the membrane integrity of S. aureus biofilm cells was investigated using flow cytometry and epifluorescence microscopy with propidium iodide staining. It was also examined the ability of 2-hydroxy-4-pyrone derivatives and 2-hydroxy-4-pyrone derivate-antibiotic dual-combinations in inhibiting the production of virulence factors (total proteases, lipases, gelatinases and siderophores) by S. aureus. Regarding biofilm formation, the results showed that 2-hydroxy-4-pyrone derivatives alone reduced the metabolic activity of S. aureus biofilm cells by over 40 %. When combined with tobramycin, a 2-log (CFU cm-2) reduction in S. aureus biofilm cells was observed. Moreover, the combination of maltol and kojic acid with ciprofloxacin prevented P. aeruginosa biomass production by 60 %, compared to 36 % with ciprofloxacin alone. In pre-established S. aureus and P. aeruginosa biofilms, selected compounds reduced the metabolic activity by over 75 %, and a 3-log (CFU cm-2) reduction in the culturability of biofilm cells was noted when kojic acid and maltol were combined with antibiotics. Moreover, 2-hydroxy-4-pyrone derivatives alone and in combination with tobramycin, damaged the cell membranes of pre-established biofilms and completely inhibited total proteases production. Despite the increasing of reactive oxygen species production caused by the cellular treatment of maltol, both 2-hydroxy-4-pyrone derivatives showed good safe profile when tested in human hepatocarcinoma (HepG2) cells. The pre-treatment of HepG2 cells with both compounds was crucial to prevent the cellular damage caused by iron (III). This study demonstrates for the first time that the selected 2-hydroxy-4-pyrone derivatives significantly enhance the antibiofilm activity of tested antibiotics against S. aureus and P. aeruginosa, highlighting their potential as antibiotic adjuvants in preventing and eradicating biofilm-related infections.

Failure or future? Exploring alternative antibacterials: a comparative analysis of antibiotics and naturally derived biopolymers

The global crisis of antimicrobial resistance (AMR) is escalating due to the misuse and overuse of antibiotics, the slow development of new therapies, and the rise of multidrug-resistant (MDR) infections. Traditional antibiotic treatments face limitations, including the development of resistance, disruption of the microbiota, adverse side effects, and environmental impact, emphasizing the urgent need for innovative alternative antibacterial strategies. This review critically examines naturally derived biopolymers with intrinsic (essential feature) antibacterial properties as a sustainable, next-generation alternative to traditional antibiotics. These biopolymers may address bacterial resistance uniquely by disrupting bacterial membranes rather than cellular functions, potentially reducing microbiota interference. Through a comparative analysis of the mechanisms and applications of antibiotics and antibacterial naturally derived biopolymers, this review highlights the potential of such biopolymers to address AMR while supporting human and environmental health.

Anti-inflammatory, immunostimulant and antimicrobial properties of tannic acid in the diet of Oreochromis niloticus infected with Aeromonas hydrophila

The study aimed to assess the impact of dietary supplementation with tannic acid on the growth, health, and survival of Oreochromis niloticus following exposure to Aeromonas hydrophila. A total of 320 fish were divided into 16 tanks and assigned to four treatment groups: feed with 0.2 % tannic acid (TA0.2 %), 0.4 % tannic acid (TA0.4 %), 0.8 % tannic acid (TA0.8 %), or no tannic acid (Control0%), with each treatment replicated four times, over a 50-day period. At the end of the 50-day period, biological samples were collected from the fish, which were then intraperitoneally injected with A. hydrophila. No significant differences in growth performance were detected between treatments. As expected, levels of total leukocytes, lymphocytes, monocytes, hemoglobin, and mean corpuscular hemoglobin concentration (MCHC) were notably higher in the blood of the fish after infection, regardless of the treatment received. During both the pre- and post-infection periods, monocytes were more abundant in the TA0.2 % and TA0.8 % treatments compared to the TA0.4 % treatment. Additionally, there was a significant interaction between the factors affecting thrombocytes, neutrophils, basophils, hemoglobin, and MCHC. Thrombocytosis and neutrophilia were significantly greater in the TA0.8 % treatment pre-infection than in the post-infection and control group. Conversely, a higher number of basophils were observed in the post-infection period in the TA0.8 % treatment group compared to the pre-infection period. Total plasma protein levels decreased significantly in the post-infection period, regardless of tannic acid supplementation levels, while immunoglobulin levels increased after exposure to A. hydrophila. Histological analyses revealed a significant increase in the perimeter and number of intestinal villi in the TA0.4 % treatment group before infection. The number of goblet cells also increased in the control group (0 %), TA0.4 %, and TA0.8 % before infection. In splenic tissue, the TA0.4 % treatment resulted in a reduction in eosinophilic and mononuclear infiltrates, as well as decreased congestion and vacuolation. Hemosiderin levels were lower in the TA0.4 % and TA0.2 % treatment groups. In the liver, lymphocytic infiltrates were reduced in the TA0.2 % and TA0.4 % treatment groups, and portal vein congestion was decreased in the TA0.2 % post-infection and TA0.4 % pre-infection groups. Post-infection survival rates were significantly higher (p < 0.05) in the TA0.4 % treatment group (91 %) compared to the TA0.8 % treatment group (85 %) and the control group (71 %). The results of the present study show that tannic acid has a positive effect on the immune system of Nile tilapia. This is supported by improvements in innate immunity in the blood, as well as the antimicrobial and anti-inflammatory effects seen in histological analyses. Therefore, it is suggested to use a 0.4 % tannic acid dose for dietary supplementation of Nile tilapia, along with further studies on the potential benefits of this food additive for tilapia.

Optimization of Piper betle L. extraction under ultrasound and its effects on chitosan/polyvinyl alcohol film properties for wound dressing

This study aimed to prepare Piper betle L. extract-load chitosan/polyvinyl alcohol (CS/PVA) film potential for wound dressing and investigate the effects of PLE and PLE-loading methods on physicochemical and biological properties of CS/PVA films. First, Piper betle L. extract (PLE) was optimized using ultrasonication and the response surface methodology employed the Box-Behnken design to maximize total phenolic content (TPC), total flavonoid content (TFC), and natural antioxidant activity. The optimal ultrasonic conditions resulting in an extract yield of 17.466 %, TPC of 261.904 mg GA/g, TFC of 148.726 mg Q/g, and IC50 of 53.100 mg/L were achieved with a sonication time of 3.958 min, power of 30.548 W, and duty cycle of 84.576 % using water as the green solvent. The systematic analysis explored the effects of extraction duration, power, and pulse mode providing valuable insights into novel extraction techniques for potential pharmaceutical applications. Subsequently, PLE was incorporated into a CS/PVA biocomposite film using two loading methods: direct mixing and immersion. The study revealed that the immersion method offers several advantages related to the physicochemical and biological properties of the PLE-treated CS/PVA film. These advantages include improved PLE bioavailability (with PLE releasing 81.42 ± 2.44 % over 24 h, 8.6 times higher than the direct mixing method), removal of excess acetic acid from the manufacturing process of CS/PVA film, which causes cell cytotoxicity (L929 cell viability of 70.47 ± 2.18 %), enhanced tensile strength of 1.19 times greater than the original CS/PVA film, and efficient exudate absorption (allowing appropriate water vapor transmission at a rate of 2477.00 ± 35.39 g/m2·day). The results show the prepared PLE-treated CS/PVA film is a potential candidate for wound dressing, and the immersion method represents an advanced drug-loading method, especially for medicinal herbs on CS/PVA thin film surfaces.

Efficacy of Willow Herb (Epilobium angustifolium L. and E. parviflorum Schreb.) Crude and Purified Extracts and Oenothein B Against Prostatic Pathogens

Background/Objectives: Plants species of the Epilobium genus are traditionally used to treat prostatitis and other urinary tract disorders and are particularly rich in ellagitannins and flavonol 3-O-glycosides. The aim of this work was to evaluate the inhibitory activity of different extracts from E. angustifolium L. and E. parviflorum Schreb. and their major bioactive compound, oenothein B, against a panel of Gram-positive (Enterococcus faecalis ATCC 29212, Enterococcus faecalis BS, Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 29213, and Staphylococcus aureus ATCC 43300) and Gram-negative (Escherichia coli ATCC 25922, Escherichia coli ATCC 35218, Escherichia coli BS, Klebsiella pneumoniae ATCC 13883, Klebsiella pneumoniae ATCC 70063, Klebsiella pneumoniae BS, Proteus mirabilis BS, and Pseudomonas aeruginosa ATCC 27853) bacteria responsible for prostatitis. Methods: Aqueous and ethanolic raw extracts were prepared, and the latter were further purified using the resin AmberliteTM XAD7HP. Then, an HPLC-MS/MS method was developed for the quantification of the marker bioactives and their levels were correlated with the antimicrobial activity. Results: Purified extracts were richer in polyphenols (330.80 and 367.66 mg/g of dry extract for E. angustifolium and E. parvifolium, respectively) than the raw extracts. Oenothein B was the predominant compound in all the extracts (119.98 to 327.57 mg/g of dry extract). The minimum inhibitory concentrations (MICs) in the range of µg/mL indicated significant antibacterial activity, which was higher for the purified extracts and oenothein B (MIC values from 4 to 16 and 8 to 1024 µg/mL on Gram-positive and Gram-negative strains, respectively). Conclusions: These results outline the outstanding potential of E. angustifolium and E. parviflorum extracts and oenothein B as therapeutic alternatives or complementary agents to conventional antibiotic treatments of prostatitis and other urinary tract infections.

Self-Assembled Nanoflowers from Natural Building Blocks with Antioxidant, Antibacterial, and Antibiofilm Properties

Polyphenols, natural compounds abundant in phenolic structures, have received widespread attention due to their antioxidant, anti-inflammatory, antibacterial, and anticancer properties, making them valuable for biomedical applications. However, the green synthesis of polyphenol-based materials with economical and environmentally friendly strategies is of great significance. In this study, a multifunctional wound dressing was achieved by introducing polyphenol-based materials of copper phosphate-tannic acid with a flower-like structure (Cu-TA NFs), which show the reactive oxygen species scavenging performance. This strategy endowed the electrospun wound dressing, composed of poly(caprolactone)-coated gum arabic-poly(vinyl alcohol) nanofibers (GPP), with the antibacterial and antibiofilm properties. Our research demonstrates that GPP/Cu-TA NFs are effective against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Furthermore, the developed GPP/Cu-TA NFs showed excellent hemocompatibility and biocompatibility. These results suggest that the synergistic properties of this multifunctional polyphenol platform (GPP/Cu-TA NFs) make it a promising candidate for the further development of wound dressing materials.

Effect of dialdehyde nanocellulose-tannin fillers on antioxidant, antibacterial, mechanical and barrier properties of chitosan films for cherry tomato preservation

In this study, bio-based composite films from nanocellulose, tannin and chitosan were fabricated. First, tannin was covalently immobilized onto dialdehyde CNCs (DACNCs) through the nucleophilic reaction to obtain TA-CNCs. TA-CNCs were then added into chitosan matrix as the nanofillers to obtain chitosan-TA-CNC (CS-TA-CNC) films. Compared with pure chitosan film, the water solubility, swelling ratio, water vapor and oxygen barrier properties of CS-TA-CNC films decreased, indicating the improved water-resistant and barrier properties. The composite films exhibited high UV blocking, antioxidant capacity and antimicrobial properties against both E. coli and S. aureus. CS-TA-CNC film with a TA-CNC content of 10 % exhibited the highest tensile strength (77.57 MPa) and toughness (23.51 MJ/m3), 2.23 and 2.5 times higher than that of pure chitosan film, respectively. The composite films extended postharvest life of tomato cherries compared to the pure chitosan film. Films prepared from sustainable bioresources show promising potential for use in active packaging.

Effects of Tithonia diversifolia Extract as a Feed Additive on Digestibility and Performance of Hair Lambs

Animal production requires efficiency, safety and environmental sustainability. Bioactive compounds from tropical plants could modulate ruminal fermentation, providing an alternative method to antibiotic treatment and addressing concerns about antibiotic resistance. In this study, the aim was to determine the effects of Tithonia diversifolia extract (TDE) on performance, intake, digestibility and blood parameters [i.e., glucose, blood urea nitrogen (BUN), aspartate aminotransferase (AST), alanine aminotransferase (ALT)] in crossbreed sheep. The main biocompounds of the TDE include caffeic acid (CA), quercetin (QCT), luteolin (LT) and apigenin (AP). Experiment 1: An in vitro dry matter digestibility (IVDMD) study was conducted to determine the optimal inclusion levels. The IVDM values were 73.09a, 82.03b, 81.01b, 73.20a and 74.51a for the control, 5, 10, 15 and 20 g/kg for the DM treatments, respectively (R-Sq adj = 0.857). The levels of 5 and 10 g were selected for the in vivo experiment. Experiment 2: Twenty-eight male crossbred hair lambs were assigned to four treatments (n = 7): control, 20 mg monensin/day, 5 g TDE/day and 10 g TDE/day groups. No differences in animal performance were observed, including body weight and feed conversion (p > 0.05). The TDE at 10 g/day improved NDF digestibility) (61.32%) and reduced the ruminal acetate to propionate ratio. The total digestible nutrients (TDN) were higher in 10 g TDE treatment with 66.41% and the lowest acetate production (67.82%) (p = 0.042), and propionate production (21.07%) were observed. The TDE were safe at 5 g and 10 g/day for liver function and exhibited lower BUN levels suggesting an improvement in protein metabolism. TDE extract at 10 g/day (TDE10), showed improvements in total tract digestibility of NDF and reduced the ruminal acetate to propionate ratio. However, due to TDE10 reducing the DM intake, the improvements in digestibility and ruminal fermentation were not reflected in growth performance improvements.

Xyloglucan based edible coating in combination with Borassus flabellifer seed coat extract for extending strawberry postharvest shelf life

In this study, xyloglucan (XG) based edible coatings were developed and combined with a bioactive compound, Borassus flabellifer seed coat extract (BFE). The effect of designed edible coatings on the quality of strawberry fruits was investigated over an 8-day storage under ambient conditions. The results revealed the preservation effects in intrinsic properties of coated strawberries that the XG/BFE coated strawberries showed superior maintenance of qualitative parameters over uncoated strawberries, showing delayed weight loss, pH, and total soluble solids, tritratable acidity, retained firmness and lightness, as well as minimized the total color difference at the end of storage. Furthermore, the inclusion of BFE significantly enhanced the antimicrobial properties of developed edible coatings, evidenced by reduced microbial load. These results paved a solid way for designing the active edible XG/BFE coating for maintaining the postharvest quality and extending the shelf life of strawberries under ambient conditions.

Microneedles as an Emerging Platform for Transdermal Delivery of Phytochemicals

Phytochemicals, which are predominantly found in plants, hold substantial medicinal value. Despite their potential, challenges such as poor oral bioavailability and instability in the gastrointestinal tract have limited their therapeutic use. Traditional intra/transdermal drug delivery systems offer some advantages over oral administration but still suffer from issues such as limited penetration depth, slow drug release rates, and inconsistent drug absorption. In contrast, microneedles (MNs) represent a significant advancement in intra/transdermal drug delivery by providing precise control over phytochemical delivery and enhanced penetration capabilities. By circumventing skin barriers, MNs directly access dermal layers rich in blood vessels and lymphatics, thus facilitating efficient phytochemical delivery. This review extensively discusses the obstacles of traditional oral delivery and the benefits of intra/transdermal delivery routes with a particular focus on the transformative potential of MNs for phytochemical delivery. This review explores the complexities of delivering phytochemicals through intra/transdermal routes, the development and types of MNs as innovative delivery tools, and the optimal design and properties of MNs for effective phytochemical delivery. Additionally, this review examines the versatile applications of MN-mediated phytochemical delivery, including its role in administering phytophotosensitizers for photodynamic therapy, and concludes with insights into relevant patents and future perspectives.

Antibacterial phenolic compounds from the flowering plants of Asia and the Pacific: coming to the light

CONTEXT

The emergence of pan-resistant bacteria requires the development of new antibiotics and antibiotic potentiators.

OBJECTIVE

This review identifies antibacterial phenolic compounds that have been identified in Asian and Pacific Angiosperms from 1945 to 2023 and analyzes their strengths and spectra of activity, distributions, molecular masses, solubilities, modes of action, structures-activities, as well as their synergistic effects with antibiotics, toxicities, and clinical potential.

METHODS

All data in this review was compiled from Google Scholar, PubMed, Science Direct, Web of Science, and library search; other sources were excluded. We used the following combination of keywords: 'Phenolic compound', 'Plants', and 'Antibacterial'. This produced 736 results. Each result was examined and articles that did not contain information relevant to the topic or coming from non-peer-reviewed journals were excluded. Each of the remaining 467 selected articles was read critically for the information that it contained.

RESULTS

Out of ∼350 antibacterial phenolic compounds identified, 44 were very strongly active, mainly targeting the cytoplasmic membrane of Gram-positive bacteria, and with a molecular mass between 200 and 400 g/mol. 2-Methoxy-7-methyljuglone, [6]-gingerol, anacardic acid, baicalin, vitexin, and malabaricone A and B have the potential to be developed as antibacterial leads.

CONCLUSIONS

Angiosperms from Asia and the Pacific provide a rich source of natural products with the potential to be developed as leads for treating bacterial infections.

Active polyvinyl alcohol films with enhanced strength, antioxidant and antibacterial properties by incorporating nanocellulose and tannin

There is an increasing demand of food packaging materials from sustainable bio- polymers. In this study, tannin-cellulose nanocrystal (TCNCs) fillers were first prepared using dialdehyde cellulose nanocrystal (DACNCs) and tannin through the nucleophilic addition reaction, and then added to PVA matrix as reinforcement fillers to fabricate active food packaging films. FT-IR analysis confirmed the successful reaction between PVA and TCNCs. The incorporation of TCNCs imparted high antibacterial, UV blocking and antioxidant capabilities to the composite films, maximumly achieving a 75 % DPPH free radical scavenging rate while blocking all UV rays. The addition of TCNCs resulted in an increase in water contact angle, alongside decreases in swelling ratio and solubility, indicating the enhanced water resistance. The composite films exhibited a 66.7 % decrease in oxygen permeability (OP) compared to the PVA film, with a slight increase observed in water vapor permeability (WVP). The tensile strength increased from 49.65 MPa to 74.17 MPa by adding 15 % of TCNCs due to the chemical crosslinking between PVA and TCNCs. Wrapping cherry tomatoes with these films prolonged the postharvest life compared to using polyethylene (PE) and pure PVA films. Films derived from sustainable biopolymers show great potential for use in fresh produce packaging.

Exploring the Variability in Phenolic Compounds and Antioxidant Capacity in Olive Oil By-Products: A Path to Sustainable Valorization

The olive oil industry generates large volumes of by-products, creating notable environmental and economic concerns. Among these, olive cake (OC)-a primary by-product of olive oil extraction-stands out due to its high content of bioactive compounds and potential for value-added recycling. This study focused on characterizing six OC samples from the Trás-os-Montes and Alto Douro regions, collected at different processing times and mills. The samples included two derived from pressing (COC), two from two-phase centrifugation (TPOC; one partially pitted and one dehydrated), and two exhausted OC (EOC) samples. Fundamental analyses assessed total phenols, ortho-diphenols, flavonoids, antioxidant capacity, and tannin content. Results revealed significant variation (p < 0.05) in phenolic composition, namely ortho-diphenols and flavonoid levels among the samples. EOC 2 exhibited the highest concentrations (19.61, 21.82, and 20.12 mg CAT/g, respectively), while COC 2 had the lowest (5.08, 5.08, and 2.76 mg GA/g, respectively). This correlated with elevated antioxidant activity in EOC 2, as measured by FRAP, DPPH, and ABTS assays (129.98, 78.00, and 56.65 μmol Trolox/g). In contrast, COC 1 and COC 2 displayed the lowest antioxidant activities (32.61 μmol Trolox/g in FRAP and 17.24 and 18.98 μmol Trolox/g in DPPH). Tannin analysis showed the highest total tannin content in the dehydrated and pitted OC samples (250.31 and 240.89 mg CAT/100 g), with COC 2 showing the lowest (88.17 mg CAT/100 g). Condensed tannin content varied significantly, with EOC 2 presenting the highest level (328.17 mg CAT/100 g) and COC 2 the lowest one (20.56 mg CAT/100 g). Through HPLC-PDA-MS, 22 compounds were identified, with luteolin and verbascoside being particularly prevalent. This in-depth characterization supports the potential valorization of olive by-products, advancing sustainability and promoting a circular economy in the olive oil sector.

Antibacterial and Antioxidant Activities, Toxicity, and Physicochemical Properties of Crassocephalum montuosum (S Moore) Milne-Redh and Crassocephalum picridifolium (DC) S Moore

In traditional Congolese medicine, the plants Crassocephalum montuosum (CrasMon) and Crassocephalum picridifolium (CrasPic) are used to treat bacterial gastroenteritis. In the present study, the antibacterial and antioxidant activities as well as the acute and subacute toxicity of organic extracts from the whole plant of the two investigated taxa were evaluated. Physicochemical parameters were also determined, and total phenolics, flavonoids, and tannins were investigated and assayed. The antibacterial and antioxidant activities of the plant extracts were evaluated using disc diffusion, tube macrodilution, and DPPH tests. Conversely, traditional solution reactions, gravimetric tests, and spectrophotometric tests were used to generate physicochemical profiles, identify secondary metabolite groups, and perform microdilution and DPPH tests to evaluate the antibacterial and antioxidant activities, respectively. OECD tests were adapted to assess the acute and subacute toxicity. All the extracts showed antibacterial activity against E. coli and S. typhi strains with the diameter zone of inhibition (DZI) ranging from 12 to 23 mm and the minimum inhibitory concentration (MIC): 15.625-125 μg·mL-1. The methanolic extract of CrasPic showed the most pronounced activity with a DZI of 21-23 mm and MIC of 15.625-62.5 μg·mL-1. All extracts showed high antioxidant activity with IC50 (half maximal inhibitory concentration) ranging from 11.6 to 21.8 μg·mL-1, with the methanolic extract of CrasMon showing the most pronounced activity. Both plants contain a variety of phytochemicals including coumarins, quinones, flavonoids, phenols, saponins, tannins, and terpenoids. The methanolic extract of CrasPic exhibits the highest content of total phenolics (300 mg·GAE·g-1), flavonoids (56 mg·QE·g-1), and tannins (155 mg·GAE·g-1). These extracts have a median lethal dose (LD50) > 5000 mg·kg-1 and no signs of toxicity at 200 mg·kg-1 after 30 days of oral administration to Cavia porcellus. The total ash content was determined to be 14.2% and 15.8% (on a dry weight basis), with the ash insoluble in hydrochloric acid exhibiting a range of 4.04%-5.03%. CrasMon and CrasPic have been demonstrated to exhibit a good antibacterial and antioxidant activities, at least in part, due to the presence of phenolic compounds. These activities may provide a rationale for their use in traditional Congolese medicine against gastroenteritis.

Tannins and copper sulphate as antimicrobial agents to prevent contamination of Posidonia oceanica seedling culture for restoration purposes

Seed-based restoration methods are increasingly recognized as a relevant tool contributing to halt and reverse the loss of seagrass meadows while providing genetic and evolutionary benefit for the conservation of these habitats. Ad-hoc protocols aimed at maximizing the survival of plantlets obtained from seeds in cultivation systems are therefore required. Previous trials of seedling culture of Posidonia oceanica, the dominant seagrass of the Mediterranean Sea, recorded up to 40% loss due to mould development. In this study we aim to (i) identify the putative causal agents of seed decay and (ii) test the efficacy of copper sulphate (0.2 and 2 ppm) and of tannin-based products derived from chestnut, tara and quebracho in reducing seed and seedling decay, while assessing possible phytotoxic effects on plant development. Halophytophthora lusitanica, H. thermoambigua and a putative new Halophytophtora species were identified as possible causal agents of seed loss. The antimicrobial agents (copper and tannins) reduced seed contamination by 20%, although copper sulphate at 2 ppm strongly inhibited the root growth. Among tannins, chestnut and tara reduced seeds germination by up to 75% and decreased shoot and root development, while quebracho showed a less severe phytotoxic effect. The use of copper sulphate at 0.2 ppm is therefore recommended to prevent P. oceanica seedling loss in culture facilities since it reduces seed contamination with no phytotoxic effects. Our results contribute to improving the seedling culture of one the key species of the Mediterranean Sea, increasing propagule availability for restoration purposes.

Zn@TA assisted dual cross-linked 3D printable glycol grafted chitosan hydrogels for robust antibiofilm and wound healing

Rapid regeneration of the injured tissue or organs is necessary to achieve the usual functionalities of the damaged parts. However, bacterial infections delay the regeneration process, a severe challenge in the personalized healthcare sector. To overcome these challenges, 3D-printable multifunctional hydrogels of Zn/tannic acid-reinforced glycol functionalized chitosan for rapid wound healing were developed. Polyphenol strengthened intermolecular connections, while glutaraldehyde stabilized 3D-printed structures. The hydrogel exhibited enhanced viscoelasticity (G'; 1.96 × 104 Pa) and adhesiveness (210 kPa). The dual-crosslinked scaffolds showed remarkable antibacterial activity against Bacillus subtilis (∼81 %) and Escherichia coli (92.75 %). The hydrogels showed no adverse effects on human dermal fibroblasts (HDFs) and macrophages (RAW 264.7), indicating their superior biocompatibility. The Zn/TA-reinforced hydrogels accelerate M2 polarization of macrophages through the activation of anti-inflammatory transcription factors (Arg-1, VEGF, CD163, and IL-10), suggesting better immunomodulatory effects, which is favorable for rapid wound regeneration. Higher collagen deposition and rapid re-epithelialization occurred in scaffold-treated rat groups vis-à-vis controls, demonstrating superior wound healing. Taken together, the developed multifunctional hydrogels have great potential for rapidly regenerating bacteria-infected wounds in the personalized healthcare sector.

Chemical Composition of Extracts from Various Parts of Feverfew (Tanacetum parthenium L.) and Their Antioxidant, Protective, and Antimicrobial Activities

Tanacetum parthenium is a medicinal plant from the Asteraceae family that can be applied externally in the case of various skin diseases. The aim of the study was to perform a phytochemical analysis of hydroethanolic extracts from the aerial parts (herb), flower heads, and leaves of feverfew and to assess their biological properties. Hydrodistilled oils were analyzed using GC-MS. The chemical composition of the extracts was estimated using spectrophotometry and the HPLC method. Moreover, the extracts were evaluated to determine their antioxidant potential using DPPH and FRAP and measuring the intracellular level of ROS. The cytotoxicity of extracts toward keratinocytes and fibroblasts was also analyzed, as well as their antimicrobial properties against 12 microorganisms. The results of the research revealed that chrysanthenone and α-thujone were the dominant volatile compounds in the essential oil from the flowers, while camphor, trans-chrysanthenyl acetate, and camphene were predominant in the essential oil from the leaves and herb. The results of HPLC showed that the major polyphenol compounds present in the hydroethanolic extracts from various parts of T. parthenium were 3,5-dicaffeoyl-quinic acid, chlorogenic acid, and 3,4-dicaffeoyl-quinic acid. The extract from feverfew flowers was shown to have the highest content of total polyphenols, flavonoids, and phenolic acids, as well as the highest antioxidant potential. In turn, the herb extract had the highest content of condensed tannins and terpenoids and exhibited the most effective antimicrobial properties against the 12 bacterial and fungal strains. Moreover, the hydroethanolic extracts from different parts of T. parthenium plants were shown to have a potent protective effect on skin cells. The present study supports the potential applications of Tanacetum parthenium in the cosmetic and pharmaceutical industries.

Antimicrobial adhesive self-healing hydrogels for efficient dental biofilm removal from periodontal tissue

OBJECTIVES

Oral biofilms, including pathogens such as Porphyromonas gingivalis, are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases.

METHODS

Phenylboronic acid-conjugated alginate (Alg-PBA) was synthesized using a carbodiimide coupling agent. Alg-PBA was then combined with tannic acid (TA) to create an Alg-PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel's self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against P. gingivalis were thoroughly characterized.

RESULTS

The Alg-PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg-PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg-PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against P. gingivalis, effectively eliminating its biofilm without compromising the viability of MG-63 cells.

SIGNIFICANCE

The Alg-PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against P. gingivalis. These attributes make it superior to conventional Minocycline gel. Thus, the Alg-PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases.

Hypersensitive quantification of major astringency markers in food and wine by substoichiometric quenching of silicon-rhodamine conjugates

Tannins are chemically diverse polyphenols in plant-derived products that not only show diverse biological activities but also play a crucial role in determining the sensory attributes of food and beverages. Therefore, their accurate and cost-effective quantification is essential. Here, we identified a novel fluorescence quenching mechanism of different synthetic rhodamine fluorophores, with a high selectivity towards tannic acid (TA) and catechin-3-gallate (C3G) compared to a structurally diverse panel of tannins and polyphenols. Specific chemical conjugates of silicon-rhodamine with alkyl linkers attached to bulky apolar moieties had a limit of detection near 500 pM and a linear range spanning 5-100 nM for TA. We validated the assay on 18 distinct red wine samples, which showed high linearity (R2 = 0.92) with methylcellulose precipitation with no interference from anthocyanins. In conclusion, a novel assay was developed and validated that allows the sensitive and selective quantification of major astringency markers abundant in food and beverages.

Multifunctional pH-responsive hydrogel dressings based on carboxymethyl chitosan: Synthesis, characterization fostering the wound healing

Antibiotic abuse is increasing the present rate of drug-resistant bacterial wound infections, producing a significant healthcare burden globally. Herein, we prepared a pH-responsive CMCS/PVP/TA (CPT) multifunctional hydrogel dressing by embedding the natural plant extract TA as a nonantibiotic and cross-linking agent in carboxymethyl chitosan (CMCS) and polyvinylpyrrolidone (PVP) to prompt wound healing. The CPT hydrogel demonstrated excellent self-healing, self-adaptive, and adhesion properties to match different wound requirements. Importantly, this hydrogel showed pH sensitivity and exhibited good activity against resistant bacteria and antioxidant activity by releasing TA in case of bacterial infection (alkaline). Furthermore, the CPT hydrogel exhibited coagulant ability and could rapidly stop bleeding within 30 s. The biocompatible hydrogel effectively accelerated wound healing in a full-thickness skin defect model by thickening granulation tissue, increasing collagen deposition, vascular proliferation, and M2-type macrophage polarization. In conclusion, this study demonstrates that multifunctional CPT hydrogel offers a candidate material with potential applications for infected skin wound healing.

Beyond the Nut: Pistacia Leaves as Natural Food Preservatives

The pistachio tree (Pistacia vera) is globally renowned for its nutritious nuts, while its leaves remain an underutilized source of chemicals with significant potential value as food preservatives. Similar value may be found in the leaves of other wild Pistacia species common in Central Asia, the Levant, and around the Mediterranean. Some species' leaves have been used as natural preservatives, demonstrating their effectiveness and highlighting their rich bioactive components. This review investigates the antioxidant and antimicrobial properties of Pistacia leaves, comparing both cultivated and wild species. A comprehensive search was performed across several scientific databases, including PubMed, Scopus, Web of Science, and Google Scholar, utilizing a combination of keywords related to Pistacia species and their bioactive compounds. The inclusion criteria focused on articles published in English from 2017 till the end of June 2024, analyzing the antioxidant and antimicrobial activities of Pistacia leaves and employing relevant extraction methods. A total of 71 literature sources were included, covering species such as P. vera, P. atlantica, P. terebinthus, and others sourced from countries such as Iran, Turkey, and Italy. This review found that Pistacia leaves are rich in polyphenolic compounds and exhibit robust antioxidant and antimicrobial properties, with certain wild species outperforming P. vera, suggesting species-specific traits that enhance their preservative potential. The major findings indicate that extracts from wild species exhibit superior bioactivity, which could be harnessed for food preservation. These insights underscore the promising role of Pistacia leaves as natural food preservatives, with further research needed to address challenges in extraction and application. Exploring their synergistic effects with other preservatives could lead to innovative solutions in food preservation while fostering local economic growth.

Antimicrobial and antibiofilm properties of procyanidins: potential for clinical and biotechnological applications

Procyanidins (PCs) have emerged as agents with potential antimicrobial and antibiofilm activities, although their mechanisms of action and structure-activity relationships remain poorly understood. This review assessed the potential mechanisms of action and applications of these compounds to explore these aspects. Studies on the antimicrobial properties of PCs suggest that they are involved in osmotic imbalance, DNA interactions and metabolic disruption. Although less studied, their antibiofilm activities include antiadhesive effects and the modulation of mobility and quorum sensing. However, most research has used uncharacterized plant extracts for in vitro assays, limiting the understanding of the structure-activity relationships of PCs and their in vivo mechanisms. Clinical trials on the antimicrobial and antibiofilm properties of PCs have not clarified these issues due to nonstandardized methodologies, inadequate chemical characterization, and the limited number of studies, preventing a consensus and evaluation of the in vivo effects. Additionally, patent analysis revealed that technological developments in the antimicrobial and antibiofilm uses of PCs are concentrated in health care and dental care, but new biotechnological uses are emerging. Therefore, while PCs are promising antimicrobial and antibiofilm compounds, further research into their chemical structures and mechanisms of action is crucial for evidence-based applications in biotechnology and health care.

Bioactivation of Konjac Glucomannan Films by Tannic Acid and Gluconolactone Addition

Wound healing is a dynamic process that requires an optimal extracellular environment, as well as an accurate synchronization between various cell types. Over the past few years, great efforts have been devoted to developing novel approaches for treating and managing burn injuries, sepsis, and chronic or accidental skin injuries. Multifunctional smart-polymer-based dressings represent a promising approach to support natural healing and address several problems plaguing partially healed injuries, including severe inflammation, scarring, and wound infection. Naturally derived compounds offer unique advantages such as minimal toxicity, cost-effectiveness, and outstanding biocompatibility along with potential anti-inflammatory and antimicrobial activity. Herein, the main driving idea of the work was the design and development of konjac glucomannan d-glucono-1,5-lactone (KG) films bioactivated by tannic acid and d-glucono-1,5-lactone (GL) addition. Our analysis, using attenuated total reflectance-Fourier transform infrared, atomic force microscopy, and surface energy measurements demonstrated that tannic acid (TA) clearly interacted with the KG matrix, acting as its cross-linker, whereas GL was embedded within the polymer structure. All developed films maintained a moist environment, which represents a pivotal property for wound dressing. Hemocompatibility experiments showed that all tested films exhibited no hemolytic impact on human erythrocytes. Moreover, the presence of TA and GL enhanced the metabolic and energetic activity in human dermal fibroblasts, as indicated by the MTT assay, showing results exceeding 150%. Finally, all films demonstrated high antibacterial properties as they significantly reduced the multiplication rate of both Staphylococcus aureus and Escherichia coli in bacterial broth and created the inhibition zones for S. aureus in agar plates. These remarkable outcomes make the KG/TA/GL film promising candidates for wound healing applications.

Smart responsive staple for dynamic promotion of anastomotic stoma healing

The precise combination of conflicting biological properties through sophisticated structural and functional design to meet all the requirements of anastomotic healing is of great demand but remains challenging. Here, we develop a smart responsive anastomotic staple (Ti-OH-MC) by integrating porous titanium anastomotic staple with multifunctional polytannic acid/tannic acid coating. This design achieves dynamic sequential regulation of antibacterial, anti-inflammatory, and cell proliferation properties. During the inflammatory phase of the anastomotic stoma, our Ti-OH-MC can release tannic acid to provide antibacterial and anti-inflammatory properties, together with immune microenvironment regulation function. At the same time, as the healing progresses, the multifunctional coating gradually falls off to expose the porous structure of the titanium anastomotic staple, which promotes cell adhesion and proliferation during the later proliferative and remodeling phases. As a result, our Ti-OH-MC exceeds the properties of clinically used titanium anastomotic staple, and can effectively promote the healing. The staple's preparation strategy is simple and biocompatible, promising for industrialisation and clinical application. This work provides an effective anastomotic staple for anastomotic stoma healing and serve as a reference for the functional design and preparation of other types of titanium-based tissue repair materials.

Tannins as antimicrobial agents: Understanding toxic effects on pathogens

"Tannins" are compounds that belong to a group of secondary metabolites found in plants. They have a polyphenolic nature and exhibit active actions as first line defenses against invading pathogens. Several studies have demonstrated the multiple activities of tannins, highlighting their effectiveness as broad-spectrum antimicrobial agents. Tannins have reported as antibacterial, antifungal, and antiviral compounds by preventing enzymatic activities and inhibiting the synthesis of nucleic acids. Additionally, tannins primarily strengthen the plant cell wall, making it almost impenetrable to harmful pathogens. Most tannins are synthesized via the phenylpropanoid pathway to become secondary metabolites. Increased uptake of tannins has the potential to provide permanent immunity to subsequent infections by strengthening cell walls and producing antimicrobial compounds. Tannins also demonstrate a synergistic response with other defense-related molecules, such as phytoalexins and pathogenesis-related proteins, including antimicrobial peptides. Studying the mechanisms mediated by tannins on pathogen behaviors would be beneficial in stimulating plant defense against pathogens. This understanding could help explain the occurrence of diseases and outbreaks and enable potential mitigation in both natural and agricultural ecosystems.

Screening Tests for the Interaction of Rubus idaeus and Rubus occidentalis Extracts with Antibiotics against Gram-Positive and Gram-Negative Human Pathogens

WHO (World Health Organization) reports from recent years warn about the growing number of antibiotic-resistant bacterial strains. Therefore, there is an urgent need to constantly search for new substances effective in the fight against microorganisms. Plants are a rich source of chemical compounds with antibacterial properties. These compounds, classified as secondary metabolites, may act independently or support the action of currently used antibiotics. Due to the large number of metabolites isolated from the plant kingdom and new plant species being studied, there is a need to develop new strategies/techniques or modifications of currently applied methods that can be used to select plant extracts or chemical compounds isolated from them that enter into positive, synergistic interactions with currently used antibiotics. One such method is the dual-disk synergy test (DDST). It involves the diffusion of active compounds in the agar environment and influencing the growth of microorganisms grown on it. The method was used to assess the interaction of extracts from the fruit and shoots of some cultivated varieties of Rubus idaeus and Rubus occidentalis with selected antibiotics. The research was conducted on strains of bacteria pathogenic to humans, including Staphylococcus aureus, Corynebacterium diphtheriae, Escherichia coli, Pseudomonas aeruginosa, Helicobacter pylori, and Candida albicans, showing synergy, antagonism, or lack of interaction of the tested substances-plant extract and antibiotic. As a result, it was found that the diffusion method is useful in screening tests to assess the impact of antibiotic-herbal substance interactions on Gram-positive and Gram-negative microorganisms.

A chemical analysis of the Pelargonium species: P. odoratissimum, P. graveolens, and P. zonale identifies secondary metabolites with activity against gram-positive bacteria with multidrug-resistance

The Pelargonium genus encompasses around 280 species, most of which are used for medicinal purposes. While P. graveolens, P. odoratissimum, and P. zonale are known to exhibit antimicrobial activity, there is an evident absence of studies evaluating all three species to understand their chemical differences and biological effects. Through the analysis of the hydroalcoholic extracts of P. graveolens, P. odoratissimum, and P. zonale, using HPLC-DAD-MS/MS, quercetin and kaempferol derivatives were identified in these three species. Conversely, gallotannins and anthocyanins were uniquely detected in P. zonale. P. graveolens stood out due to the various types of myricetin derivatives that were not detected in P. odoratissimum and P. zonale extracts. Evaluation of their biological activities revealed that P. zonale displayed superior antibacterial and antibiofilm activities in comparison to the other two species. The antibacterial efficacy of P. zonale was observed towards the clinically relevant strains of Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) 333, Enterococcus faecalis ATCC 29212, and the Vancomycin-resistant E. faecalis INSPI 032. Fractionation analysis of P. zonale suggested that the antibacterial activity attributed to this plant is due to the presence of quercetin derivatives and kaempferol and its derivatives, alongside their synergistic interaction with gallotannins and anthocyanins. Lastly, the three Pelargonium species exhibited notable antioxidant activity, which may be attributed to their high content of total phenolic compounds.

Deep eutectic solvents for the extraction of polyphenols from food plants

Deep Eutectic Solvents (DESs) offer a promising, sustainable alternative for extracting polyphenols from food plants, known for their health benefits. Traditional extraction methods are often costly and involve toxic solvents. This review discusses the basic concepts, preparation techniques, and factors influencing the effective and safe use of DESs in polyphenol extraction. DESs' adaptability allows integration with other green extraction technologies, such as microwave- and ultrasound-assisted extractions, enhancing their efficiency. This adaptability demonstrates the potential of DESs in the sustainable extraction of bioactive compounds. Current research indicates that DESs could play a significant role in the sustainable procurement of these compounds, marking an important advancement in food science research and development. The review underscores DESs as a realistic, eco-friendly alternative in the realm of natural extraction technologies, offering a significant contribution to sustainable practices in food science.

Opportunities and challenges in antimicrobial resistance policy including animal production systems and humans across stakeholders in Argentina: a context and qualitative analysis

INTRODUCTION

Gaps in antimicrobial resistance (AMR) surveillance and control, including implementation of national action plans (NAPs), are evident internationally. Countries' capacity to translate political commitment into action is crucial to cope with AMR at the human-animal-environment interface.

METHODS

We employed a two-stage process to understand opportunities and challenges related to AMR surveillance and control at the human-animal interface in Argentina. First, we compiled the central AMR policies locally and mapped vital stakeholders around the NAP and the national commission against bacterial resistance. Second, we conducted qualitative interviews using a semistructured questionnaire covering stakeholders' understanding and progress towards AMR and NAP. We employed a mixed deductive-inductive approach and used the constant comparative analysis method. We created categories and themes to cluster subthemes and determined crucial relationships among thematic groups.

RESULTS

Crucial AMR policy developments have been made since 1969, including gradually banning colistin in food-producing animals. In 2023, a new government decree prioritised AMR following the 2015 NAP launch. Our qualitative analyses identified seven major themes for tackling AMR: (I) Cultural factors and sociopolitical country context hampering AMR progress, (II) Fragmented governance, (III) Antibiotic access and use, (IV) AMR knowledge and awareness throughout stakeholders, (V) AMR surveillance, (VI) NAP efforts and (VII) External drivers. We identified a fragmented structure of the food production chain, poor cross-coordination between stakeholders, limited surveillance and regulation among food-producing animals and geographical disparities over access, diagnosis and treatment. The country is moving to integrate animal and food production into its surveillance system, with most hospitals experienced in monitoring AMR through antimicrobial stewardship programmes.

CONCLUSION

AMR accountability should involve underpinning collaboration at different NAP implementation levels and providing adequate resources to safeguard long-term sustainability. Incorporating a multisectoral context-specific approach relying on different One Health domains is crucial to strengthening local AMR surveillance.

Hoslundia opposita vahl; a potential source of bioactive compounds with antioxidant and antibiofilm activity for wound healing

BACKGROUND

Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination. Antioxidants work synergistically with antibacterial agents against biofilms. Hence recent research has suggested plants as candidates in the development of new alternatives in biofilm treatments and as antioxidants due to the presence of phytocompounds which are responsible for their bioactivities. Hoslundia opposita Vahl is one of the plants used by traditional healers to treat wounds and other infections, this makes it a potential candidate for drug discovery hence, in this study, we investigate the antibiofilm and antioxidant activity of methanolic extract of hoslundia opposita Vahl from Uganda. We also identify phytochemicals responsible for its bioactivity.

METHOD

the plant was extracted by maceration using methanol, and the extract was investigated for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. The antibiofilm activity using microtiter plate assay (MTP) assay where the Minimum biofilm inhibitory concentration required to inhibit 50% or 90% of the biofilm (MBIC50 and MBIC90) and Minimum biofilm eradication concentration required to remove 50% or 90% of the biofilm (MBEC50 and MBEC90) were measured. It was further analysed for its phytochemical composition using quantitative screening, as well as Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography mass-spectrometry (LC-MS).

RESULTS

H. Opposita Vahl extract showed good antioxidant activity with of 249.6 mg/mL. It inhibited the growth of P. aeruginosa and S. aureus biofilms with MBIC50 of 28.37 mg/mL and 10 mg/mL, respectively. It showed the ability to eradicate P. aeruginosa and S. aureus biofilms with MBEC50 of 23.85 and 39.01 mg/mL respectively. Phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, and phenols. GC-MS analysis revealed 122 compounds in the extract of which, 23 have evidence of antioxidant or antibiofilm activity in literature. The most abundant compounds were; 1,4- Citric acid, Tetracontane-1,40-diol (43.43.3%, 1, Olean-12-en-28-oic acid, 3-hydroxy-, methyl ester, (3.beta) (15.36%) 9-Octadecenamide (12.50%), Squalene (11.85%) Palmitic Acid 4TMS (11.28%), and alpha Amyrin (11.27%). The LC-MS identified 115 and 57 compounds in multiple reaction mode (MRM) and scan modes respectively.

CONCLUSION

H. opposita Vahl showed antibiofilm and antioxidant activity due to bioactive compounds identified, hence the study justifies its use for wound healing. It can be utilised in further development of new drugs as antibiofilm and antioxidants.

A Comprehensive Analysis of Diversity, Structure, Biosynthesis and Extraction of Biologically Active Tannins from Various Plant-Based Materials Using Deep Eutectic Solvents

This paper explores the emerging subject of extracting tannins from various plant sources using deep eutectic solvents (DESs). Tannins are widely used in the food and feed industries as they have outstanding antioxidant qualities and greatly enhance the flavor and nutritional content of a wide range of food products. Organic solvents are frequently used in traditional extraction techniques, which raises questions about their safety for human health and the environment. DESs present a prospective substitute because of their low toxicity, adaptability, and environmental friendliness. The fundamental ideas supporting the application of DESs in the extraction of tannins from a range of plant-based materials frequently used in daily life are all well covered in this paper. Furthermore, this paper covers the impact of extraction parameters on the yield of extracted tannins, as well as possible obstacles and directions for future research in this emerging subject. This includes challenges such as high viscosity, intricated recovery of compounds, thermal degradation, and the occurrence of esterification. An extensive summary of the diversity, structure, biosynthesis, distribution, and roles of tannins in plants is given in this paper. Additionally, this paper thoroughly examines various bioactivities of tannins and their metabolites.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

Antibacterial, antioxidant, Cr(VI) adsorption and dye adsorption effects of biochar-based silver nanoparticles‑sodium alginate-tannic acid composite gel beads

Ultrasonic extraction of Osmanthus fragrans was used for reducing Ag+ to prepare AgNPs, which were further loaded on barley distiller's grains shell biochar. By supplementary of sodium alginate and tannic acid, composite gel beads were prepared. The physical properties of biochar-based AgNPs‑sodium alginate-tannic acid composite gel beads (C-Ag/SA/TA) were characterized. SEM, FTIR, and XRD showed that biochar-based AgNPs were compatible with sodium alginate-tannic acid. CAg greatly improved the dissolution, swelling, and expansion of gel beads. Through the analysis by the agar diffusion method, C-Ag/SA/TA gel beads had high antibacterial activity (inhibition zone: 22 mm against Escherichia coli and 20 mm against Staphylococcus aureus). It was observed that C-Ag/SA/TA composite gel beads had high antioxidant capacity and the free radical scavenging rate reached 89.0 %. The dye adsorption performance of gel beads was studied by establishing a kinetic model. The maximum adsorption capacities of C-Ag/SA/TA gel beads for methylene blue and Congo red were 166.57 and 318.06 mg/g, respectively. The removal rate of Cr(VI) reached 96.4 %. These results indicated that the prepared composite gel beads had a high adsorption capacity for dyes and metal ions. Overall, C-Ag/SA/TA composite gel beads were biocompatible and had potential applications in environmental pollution treatment.

Exploring the Role of Phenolic Compounds in Chronic Kidney Disease: A Systematic Review

Chronic kidney disease (CKD) presents a formidable global health concern, affecting one in six adults over 25. This review explores the potential of phenolic compounds in managing CKD and its complications. By examining the existing research, we highlight their diverse biological activities and potential to combat CKD-related issues. We analyze the nutritional benefits, bioavailability, and safety profile of these compounds. While the clinical evidence is promising, preclinical studies offer valuable insights into underlying mechanisms, optimal dosages, and potential side effects. Further research is crucial to validate the therapeutic efficacy of phenolic compounds for CKD. We advocate for continued exploration of their innovative applications in food, pharmaceuticals, and nutraceuticals. This review aims to catalyze the scientific community's efforts to leverage phenolic compounds against CKD-related challenges.

Phytochemical Analysis and Anti-Biofilm Potential That Cause Dental Caries from Black Cumin Seeds (Nigella sativa Linn.)

The oral cavity is an excellent place for various microorganisms to grow. Spectrococcus mutans and Spectrococcus sanguinis are Gram-negative bacteria found in the oral cavity as pioneer biofilm formers on the tooth surface that cause caries. Caries treatment has been done with antibiotics and therapeutics, but the resistance level of S. mutans and S. sanguinis bacteria necessitates the exploration of new drug compounds. Black cumin (Nigella sativa Linn.) is known to contain secondary metabolites that have antioxidant, antibacterial, anti-biofilm, anti-inflammatory and antifungal activities. The purpose of this review article is to present data on the potential of Nigella sativa Linn seeds as anti-biofilm. This article will discuss biofilm-forming bacteria, the resistance mechanism of antibiotics, the bioactivity of N. sativa extracts and seed isolates together with the Structure Activity Relationship (SAR) review of N. sativa compound isolates. We collected data from reliable references that will illustrate the potential of N. sativa seeds as anti-biofilm drug.

Antimicrobial Metabolites of Caucasian Medicinal Plants as Alternatives to Antibiotics

This review explores the potential of antimicrobial metabolites derived from Caucasian medicinal plants as alternatives to conventional antibiotics. With the rise of antibiotic resistance posing a global health threat, there is a pressing need to investigate alternative sources of antimicrobial agents. Caucasian medicinal plants have traditionally been used for their therapeutic properties, and recent research has highlighted their potential as sources of antimicrobial compounds. Representatives of 15 families of Caucasian medicinal plant extracts (24 species) have been explored for their efficacy against these pathogens. The effect of these plants on Gram-positive and Gram-negative bacteria and fungi is discussed in this paper. By harnessing the bioactive metabolites present in these plants, this study aims to contribute to the development of new antimicrobial treatments that can effectively combat bacterial infections while minimizing the risk of resistance emergence. Herein we discuss the following classes of bioactive compounds exhibiting antimicrobial activity: phenolic compounds, flavonoids, tannins, terpenes, saponins, alkaloids, and sulfur-containing compounds of Allium species. The review discusses the pharmacological properties of selected Caucasian medicinal plants, the extraction and characterization of these antimicrobial metabolites, the mechanisms of action of antibacterial and antifungal plant compounds, and their potential applications in clinical settings. Additionally, challenges and future directions in the research of antimicrobial metabolites from Caucasian medicinal plants are addressed.

Infection-Free and Enhanced Wound Healing Potential of Alginate Gels Incorporating Silver and Tannylated Calcium Peroxide Nanoparticles

The treatment of chronic wounds involves precise requirements and complex challenges, as the healing process cannot go beyond the inflammatory phase, therefore increasing the healing time and implying a higher risk of opportunistic infection. Following a better understanding of the healing process, oxygen supply has been validated as a therapeutic approach to improve and speed up wound healing. Moreover, the local implications of antimicrobial agents (such as silver-based nano-compounds) significantly support the normal healing process, by combating bacterial contamination and colonization. In this study, silver (S) and tannylated calcium peroxide (CaO2@TA) nanoparticles were obtained by adapted microfluidic and precipitation synthesis methods, respectively. After complementary physicochemical evaluation, both types of nanoparticles were loaded in (Alg) alginate-based gels that were further evaluated as possible dressings for wound healing. The obtained composites showed a porous structure and uniform distribution of nanoparticles through the polymeric matrix (evidenced by spectrophotometric analysis and electron microscopy studies), together with a good swelling capacity. The as-proposed gel dressings exhibited a constant and suitable concentration of released oxygen, as shown for up to eight hours (UV-Vis investigation). The biofilm modulation data indicated a synergistic antimicrobial effect between silver and tannylated calcium peroxide nanoparticles, with a prominent inhibitory action against the Gram-positive bacterial biofilm after 48 h. Beneficial effects in the human keratinocytes cultured in contact with the obtained materials were demonstrated by the performed tests, such as MTT, LDH, and NO.

Coxiella burnetii in domestic doe goats in the United States, 2019-2020

Coxiella burnetii is a bacterial pathogen capable of causing serious disease in humans and abortions in goats. Infected goats can shed C. burnetii through urine, feces, and parturient byproducts, which can lead to infections in humans when the bacteria are inhaled. Goats are important C. burnetii reservoirs as evidenced by goat-related outbreaks across the world. To better understand the current landscape of C. burnetii infection in the domestic goat population, 4,121 vaginal swabs from 388 operations across the United States were analyzed for the presence of C. burnetii by IS1111 PCR as part of the United States Department of Agriculture, Animal Plant Health Inspection Service, Veterinary Services' National Animal Health Monitoring System Goats 2019 Study. In total, 1.5% (61/4121) of swabs representing 10.3% (40/388) (weighted estimate of 7.8, 95% CI 4.4-13.5) of operations were positive for C. burnetii DNA. The quantity of C. burnetii on positive swabs was low with an average Ct of 37.9. Factors associated with greater odds of testing positive included suspected Q fever in the herd in the previous 3 years, the presence of wild deer or elk on the operation, and the utilization of hormones for estrus synchronization. Factors associated with reduced odds of testing positive include the presence of kittens and treatment of herds with high tannin concentrate plants, diatomaceous earth, and tetrahydropyrimidines. In vitro analysis demonstrated an inhibitory effect of the tetrahydropyrimidine, pyrantel pamoate, on the growth of C. burnetii in axenic media as low as 1 μg per mL. The final multivariable logistic regression modeling identified the presence of wild predators on the operation or adjacent property (OR = 9.0, 95% CI 1.3-61.6, p value = 0.0248) as a risk factor for C. burnetii infection.