Protective Potential of a Botanical-Based Supplement Ingredient against the Impact of Environmental Pollution on Cutaneous and Cardiopulmonary Systems: Preclinical Study

Air pollution is a growing threat to human health. Airborne pollution effects on respiratory, cardiovascular and skin health are well-established. The main mechanisms of air-pollution-induced health effects involve oxidative stress and inflammation. The present study evaluates the potential of a polyphenol-enriched food supplement ingredient comprising Lippia citriodora, Olea europaea, Rosmarinus officinalis, and Sophora japonica extracts in mitigating the adverse effects of environmental pollution on skin and cardiopulmonary systems. Both in vitro and ex vivo studies were used to assess the blend's effects against pollution-induced damage. In these studies, the botanical blend was found to reduce lipid peroxidation, inflammation (by reducing IL-1α), and metabolic alterations (by regulating MT-1H, AhR, and Nrf2 expression) in human skin explants exposed to a mixture of pollutants. Similar results were also observed in keratinocytes exposed to urban dust. Moreover, the ingredient significantly reduced pollutant-induced ROS production in human endothelial cells and lung fibroblasts, while downregulating the expression of apoptotic genes (bcl-2 and bax) in lung fibroblasts. Additionally, the blend counteracted the effect of urban dust on the heart rate in zebrafish embryos. These results support the potential use of this supplement as an adjuvant method to reduce the impact of environmental pollution on the skin, lungs, and cardiovascular tissues.

Porous Zinc Oxide and Plant Polyphenols as a Replacement for High-Dose Zinc Oxide on Growth Performance, Diarrhea Incidence, Intestinal Morphology and Microbial Diversity of Weaned Piglets

The aim of this experiment is to evaluate the effects of adding porous zinc oxide, plant polyphenols, and their combination to diets without antibiotics and high-dose zinc oxide on the growth performance, diarrhea incidence, intestinal morphology, and microbial diversity of weaned piglets. A total of 150 Duroc × Landrace × Large White weaned piglets were allocated to one of five diets in a randomized complete block design with six replicates and five piglets per replicate. The experimental period was 42 d, divided into two feeding stages: pre-starter (0-14 d) and starter (14-42 d). In the pre-starter stage, the negative control group (NC) was fed a basal diet, the positive control group (PC) was fed a basal diet with 2000 mg/kg of zinc oxide, the porous zinc oxide group (PZ) was fed a basal diet with 500 mg/kg of porous zinc oxide, the plant polyphenol group (PP) was fed a basal diet with 1500 mg/kg of plant polyphenols, and the combination group (PZ + PP) was fed a basal diet with 500 mg/kg of porous zinc oxide and 1500 mg/kg of plant polyphenols. In the starter stage, the NC, PC, and PZ groups were fed a basal diet, while the PP and PZ + PP groups were fed a basal diet with 1000 mg/kg of plant polyphenols. The results showed that, (1) compared with the PZ group, adding plant polyphenols to the diet showed a trend of increasing the ADFI of weaned piglets from 14 to 28 d (p = 0.099). From days 28 to 42 and days 0 to 42, porous zinc oxide and the combination of porous zinc oxide and plant polyphenols added to the control diet improved the FCR to the level observed in pigs fed the PC diet. (2) Dietary PZ + PP tended to increase the jejunal villus height (VH) of weaned piglets (p = 0.055), and significantly increased the villus-height-to-crypt-depth ratio compared to the NC group (p < 0.05). (3) Compared with the NC group, PZ supplementation decreased the relative abundance of Firmicutes and increased the relative abundance of Bacteroidetes, and the relative abundance of Lactobacillus in the PZ and PZ + PP groups were both increased. In conclusion, porous zinc oxide and plant polyphenols may have synergistic effects in modulating intestinal health in weaned piglets and be a potential alternative to high-dose zinc oxide.

Cranberry Proanthocyanidins Mitigate Reflux-Induced Transporter Dysregulation in an Esophageal Adenocarcinoma Model

We recently reported that cranberry proanthocyanidins (C-PACs) inhibit esophageal adenocarcinoma (EAC) by 83% through reversing reflux-induced bacterial, inflammatory and immune-implicated proteins and genes as well as reducing esophageal bile acids, which drive EAC progression. This study investigated whether C-PACs' mitigation of bile reflux-induced transporter dysregulation mechanistically contributes to EAC prevention. RNA was isolated from water-, C-PAC- and reflux-exposed rat esophagi with and without C-PAC treatment. Differential gene expression was determined by means of RNA sequencing and RT-PCR, followed by protein assessments. The literature, coupled with the publicly available Gene Expression Omnibus dataset GSE26886, was used to assess transporter expression levels in normal and EAC patient biopsies for translational relevance. Significant changes in ATP-binding cassette (ABC) transporters implicated in therapeutic resistance in humans (i.e., Abcb1, Abcb4, Abcc1, Abcc3, Abcc4, Abcc6 and Abcc10) and the transport of drugs, xenobiotics, lipids, and bile were altered in the reflux model with C-PACs' mitigating changes. Additionally, C-PACs restored reflux-induced changes in solute carrier (SLC), aquaporin, proton and cation transporters (i.e., Slc2a1, Slc7a11, Slc9a1, Slco2a1 and Atp6v0c). This research supports the suggestion that transporters merit investigation not only for their roles in metabolism and therapeutic resistance, but as targets for cancer prevention and targeting preventive agents in combination with chemotherapeutics.

Effects of Plant-Derived Polyphenols on the Antioxidant Activity and Aroma of Sulfur-Dioxide-Free Red Wine

Significant efforts have been made in recent years to produce healthier wines, with the primary goal of reducing the use of sulfur dioxide (SO₂), which poses health risks. This study aimed to assess the effectiveness of three plant-derived polyphenols (dihydromyricetin, resveratrol, and catechins) as alternatives to SO₂ in wine. After a three-month aging process, the wines were evaluated using analytical techniques such as high-performance liquid chromatography, colorimetry, gas chromatography-olfactometry-mass spectrometry, as well as electronic nose and electronic tongue analyses, with the purpose to assess parameters including antioxidant activity, color, contents of volatile aroma compounds, and sensory characteristics. The results demonstrated various degrees of improvement in the antioxidant activity, aromatic intensity, and sensory characteristics of wines using polyphenols. Notably, dihydromyricetin (200 mg/L) exhibited the strongest antioxidant activity, with increases of 18.84%, 23.28%, and 20.87% in 2,2-diphenyl-1-picrylhydrazyl, 2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric-ion-reducing antioxidant power assays, respectively. Resveratrol (200 mg/L) made the most significant contribution to volatile aroma compounds, with an 8.89% increase in the total content of alcohol esters. In E-nose analysis, catechins (200 mg/L) showed the highest response to aromatic compounds and the lowest response to volatile sulfur compounds, while also exhibiting the best sensory characteristics. Therefore, the three plant-derived polyphenols investigated here exhibited the potential to enhance wine quality as alternatives to SO₂. However, it is important to consider the specific impact of different polyphenols on wine; hence, suitable antioxidants should be selected in wine production according to specific requirements.

Insights on the Role of Polyphenols in Combating Cancer Drug Resistance

Chemotherapy resistance is still a serious problem in the treatment of most cancers. Many cellular and molecular mechanisms contribute to both inherent and acquired drug resistance. They include the use of unaffected growth-signaling pathways, changes in the tumor microenvironment, and the active transport of medicines out of the cell. The antioxidant capacity of polyphenols and their potential to inhibit the activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, as well as to promote the inhibition or downregulation of active drug efflux transporters, have been linked to a reduced risk of cancer in epidemiological studies. Polyphenols also have the ability to alter immunological responses and inflammatory cascades, as well as trigger apoptosis in cancer cells. The discovery of the relationship between abnormal growth signaling and metabolic dysfunction in cancer cells highlights the importance of further investigating the effects of dietary polyphenols, including their ability to boost the efficacy of chemotherapy and avoid multidrug resistance (MDR). Here, it is summarized what is known regarding the effectiveness of natural polyphenolic compounds in counteracting the resistance that might develop to cancer drugs as a result of a variety of different mechanisms.

Exploring plant polyphenols as anti-allergic functional products to manage the growing incidence of food allergy

The active substances derived from plants have received increasing attention owing to their wide range of pharmacological applications, including anti-tumor, anti-allergic, anti-viral, and anti-oxidative activities. The allergy epidemic is a growing global public health problem that threatens human health and safety. Polyphenols from plants have significant anti-allergic effects and are an important source of anti-allergic drug research and development. Here, we describe recent advances in the anti-allergic efficacy of plant polyphenols, including their comprehensive effects on cellular or animal models. The current issues and directions for future development in this field are discussed to provide a theoretical basis for the development and utilization of these active substances as anti-allergic products.

Synthesis of Flavonol-Bearing Probes for Chemoproteomic and Bioinformatic Analyses of Asteraceae Petals in Search of Novel Flavonoid Enzymes

This study aimed at searching for the enzymes that are responsible for the higher hydroxylation of flavonols serving as UV-honey guides for pollinating insects on the petals of Asteraceae flowers. To achieve this aim, an affinity-based chemical proteomic approach was developed by relying on the use of quercetin-bearing biotinylated probes, which were thus designed and synthesized to selectively and covalently capture relevant flavonoid enzymes. Proteomic and bioinformatic analyses of proteins captured from petal microsomes of two Asteraceae species (Rudbeckia hirta and Tagetes erecta) revealed the presence of two flavonol 6-hydroxylases and several additional not fully characterized proteins as candidates for the identification of novel flavonol 8-hydroxylases, as well as relevant flavonol methyl- and glycosyltransferases. Generally speaking, this substrate-based proteome profiling methodology constitutes a powerful tool for the search for unknown (flavonoid) enzymes in plant protein extracts.

Influence of Azadirachta indica and Cnidoscolus angustidens aqueous extract on cattle ruminal gas production and degradability in vitro

Introduction

Mitigation of ruminant greenhouse gas (GHG) emissions is crucial for more appropriate livestock production. Thus, there is a need of further research evaluating feed supplementation strategies to mitigate enteric GHG emissions and other gases produced within the rumen.

Methods

This study was conducted as a completely randomized experimental design to determine the effectiveness of liquid extracts from A. indica (AZI), C. angustidens (CNA), or their combination (Mix. 1:1) at dosages of 0, 36, 72, and 108 mg of liquid extract/g DM substrate incubated in reducing GHG production in vitro, particularly methane (CH4), from the diet of steers during anaerobic incubation in rumen fluid. Total gas production, CH4, CO, H2S, and fermentative characteristics were all measured in vitro.

Results

Treatment AZI at a dose of 108 mg of liquid extract/g DM substrate produced the highest (P < 0.05) gas volume at 6 h, whereas CNA at a dose of 72 mg of liquid extract/ g DM substrate produced the least (P < 0.05) at 6 and 24 h, and Mix. at a dose of 72 mg of liquid extract/g DM substrate produced the least (P < 0.05) at 48 h. In addition, CH4 levels at 6 and 24 h of incubation (36 mg/g DM substrate) were highest (P < 0.05) for CNA, and lowest (P < 0.05) for AZI, whereas this variable was lowest (P < 0.05) at 72 mg of liquid extract for CNA at 24 and 48 h. At 6 and 24 h, CO volume was highest (P < 0.05) for AZI at 108 mg of liquid extract and lowest (P < 0.05) for Mix. at 72 mg of liquid extract. Treatment Mix. had a high (P < 0.05) concentration of short chain fatty acids at 72 mg of liquid extract/g DM of substrate.

Discussion

In general, herbaceous perennial plants, such as AZI and CNA, could be considered suitable for mitigating enteric GHG emissions from animals. Specifically, the treatment Mix. achieved a greater sustainable reduction of 67.6% in CH4 and 47.5% in H2S production when compared to either AZI. This reduction in CH4 might suggest the potential of the combination of both plant extracts for mitigating the production of GHG from ruminants.

Possible Mechanisms of Oxidative Stress-Induced Skin Cellular Senescence, Inflammation, and Cancer and the Therapeutic Potential of Plant Polyphenols

As the greatest defense organ of the body, the skin is exposed to endogenous and external stressors that produce reactive oxygen species (ROS). When the antioxidant system of the body fails to eliminate ROS, oxidative stress is initiated, which results in skin cellular senescence, inflammation, and cancer. Two main possible mechanisms underlie oxidative stress-induced skin cellular senescence, inflammation, and cancer. One mechanism is that ROS directly degrade biological macromolecules, including proteins, DNA, and lipids, that are essential for cell metabolism, survival, and genetics. Another one is that ROS mediate signaling pathways, such as MAPK, JAK/STAT, PI3K/AKT/mTOR, NF-κB, Nrf2, and SIRT1/FOXO, affecting cytokine release and enzyme expression. As natural antioxidants, plant polyphenols are safe and exhibit a therapeutic potential. We here discuss in detail the therapeutic potential of selected polyphenolic compounds and outline relevant molecular targets. Polyphenols selected here for study according to their structural classification include curcumin, catechins, resveratrol, quercetin, ellagic acid, and procyanidins. Finally, the latest delivery of plant polyphenols to the skin (taking curcumin as an example) and the current status of clinical research are summarized, providing a theoretical foundation for future clinical research and the generation of new pharmaceuticals and cosmetics.

Amphotericin B-Loaded Plant-Inspired Polyphenol Nanoparticles Enhance Its Antifungal Activity and Biocompatibility

Amphotericin B (AmB) is one of the first-line treatments for systemic fungal infections, yet it suffers from dose-limiting systemic toxicity and high cost of less toxic lipid-based formulations. Here, we report on a facile approach to synthesize an AmB-loaded nanomedicine by leveraging plant-inspired oxidative self-polymerization of the ubiquitous polyphenol quercetin (QCT). Polymerized QCT nanoparticles (pQCT NPs) were formed, loaded with AmB, and functionalized with poly(ethylene glycol) (PEG) to impart steric stability in a simple procedure that relied on mixing followed by dialysis. The AmB-loaded NPs (AmB@pQCT-PEG NPs) were characterized by a drug loading efficiency of more than 90%, a particle size of around 160 nm, a polydispersity index of 0.07, and a partially negative surface charge. AmB release from the NPs was sustained over several days and followed the Korsmeyer-Peppas model with a release exponent (n) value >0.85, denoting drug release by polymer relaxation and swelling. A hemolysis assay revealed the NPs to be highly biocompatible, with negligible hemolytic activity and 30-60% hemolysis after 1 and 24 h of incubation with erythrocytes, respectively, across a wide concentration range (6.25-100.00 μg/mL). Conversely, equivalent concentrations of free AmB caused 90-100% hemolysis within the same timeframe. Importantly, AmB@pQCT-PEG NPs outperformed free AmB in microbial susceptibility assays on Candida albicans, achieving a minimum inhibitory concentration of 62.5 ng/mL after 48 h of incubation, which was 2-fold lower than the free drug. Our results demonstrate that pQCT NPs may serve as a viable AmB delivery platform for the treatment of fungal infections and potentially other AmB-susceptible pathogens.

Plant-Derived Catechols Are Substrates of TonB-Dependent Transporters and Sensitize Pseudomonas aeruginosa to Siderophore-Drug Conjugates

Pseudomonas aeruginosa is an opportunistic pathogen responsible for acute and chronic infections in immunocompromised hosts. This organism is known to compete efficiently against coinfecting microorganisms, due in part to the secretion of antimicrobial molecules and the synthesis of siderophore molecules with high affinity for iron. P. aeruginosa possess a large repertoire of TonB-dependent transporters for the uptake of its own, as well as xenosiderophores released from other bacteria or fungi. Here, we show that P. aeruginosa is also capable of utilizing plant-derived polyphenols as an iron source. We found that exclusively plant-derived phenols containing a catechol group (i.e., chlorogenic acid, caffeic acid, quercetin, luteolin) induce the expression of the TonB-dependent transporters PiuA or PirA. This induction requires the two-component system PirR-PirS. Chlorogenic acid in its Fe(III)-loaded form was actively transported by PiuA and PirA and supported growth under iron-limiting conditions. Coincidentally, PiuA and PirA are also the main TonB transporters for the recently approved siderophore-drug conjugate cefiderocol. Surprisingly, quercetin supplementation increased the susceptibility of P. aeruginosa to siderophore-drug conjugates, due to induction of piuA and pirA expression mediated by the PirR-PirS two-component system. These findings suggest a potential novel therapeutic application for these biologically active dietary polyphenols.

Polyphenols in Ruminant Nutrition and Their Effects on Reproduction

The feeding of domestic animals with diets in which polyphenols are present is increasingly attracting the attention of nutritionists and scientists. This review summarizes the knowledge regarding polyphenols' possible positive and negative effects and their bioavailability. The bioavailability of substances is a prerequisite for any postabsorption effect in vivo. Positive and negative properties have been confirmed in previous studies on the diets of domestic animals rich in polyphenols, such as secondary metabolites of plants. Free radicals are formed in every organism, leading to oxidative stress. Free radicals are highly reactive molecules and can react in cells with macromolecules and can cause damage, including in reproductive cells. Some polyphenols at specific concentrations have antioxidant properties that positively affect animal reproduction by improving the quality of male and female gametes. The intake of phytoestrogens that mimic estrogen function can induce various pathological conditions in the female reproductive tract, including ovarian, fallopian, and uterine dysfunction. The metabolism of genistein and daidzein yields the metabolites equol and p-phenyl-phenol, leading to a decline in cow fertilization. The findings so far confirm that numerous questions still need to be answered. This review points out the importance of using polyphenols that have both benificial and some unfavorable properties in specific diets.

Review on the Regulation of Plant Polyphenols on the Stability of Polyunsaturated-Fatty-Acid-Enriched Emulsions: Partitioning Kinetic and Interfacial Engineering

The plant polyphenols are normally presented as natural functional antioxidants, which also possess the potential ability to improve the physicochemical stability of polyunsaturated fatty acid (PUFA)-enriched emulsions by interface engineering. This review discussed the potential effects of polyphenols on the stability of PUFA-enriched emulsions from the perspective of the molecular thermodynamic antioxidative analysis, the kinetic of interfacial partitioning, and the covalent and non-covalent interactions with emulsifiers. Recently, research studies have proven that the interfacial structure of emulsions can be concurrently optimized via promoting interfacial partitioning of polyphenols and further increasing interfacial thickness and strength. Moreover, the applied limitations of polyphenols in PUFA-enriched emulsions were summarized, and then some valuable and constructive viewpoints were put forward in this review to provide guidance for the use of polyphenols in constructing PUFA-enriched emulsions.

Chitooligosaccharide Conjugates Prepared Using Several Phenolic Compounds via Ascorbic Acid/H(2)O(2) Free Radical Grafting: Characteristics, Antioxidant, Antidiabetic, and Antimicrobial Activities

Chitooligosaccharide (COS)-polyphenol (PPN) conjugates prepared using different PPNs, including gallic, caffeic, and ferulic acids, epigallocatechin gallate, and catechin, at various concentrations were characterized via UV-visible, FTIR, and 1H-NMR spectra and tested for antioxidant, antidiabetic, and antimicrobial activities. Grafting of PPNs with COS was achieved. The highest conjugation efficiency was noticed for COS-catechin (COS-CAT), which was identified to have the highest total phenolic content (TPC) out of all the conjugates (p < 0.05). For antioxidant activities, DPPH and ABTS radical scavenging activities (DPPH-RSA and ABTS-RSA, respectively), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and metal chelating activity (MCA) of all the samples were positively correlated with the TPC incorporated. COS-CAT had higher DPPH-RSA, ABTS-RSA, ORAC, and FRAP than COS and all other COS-PPN conjugates (p < 0.05). In addition, COS-CAT also showed the highest antidiabetic activity of the conjugates, as determined by inhibitory activity toward α-amylase, α-glucosidase, and pancreatic lipase (p < 0.05). COS-CAT also had the highest antimicrobial activity against all tested Gram-negative and Gram-positive bacteria (p < 0.05). Overall, grafting of PPNs, especially CAT on COS, significantly enhanced bioactivities, including antioxidant and antimicrobial, which could be used to retard spoilage and enhance shelf-life of various food systems. Moreover, the ability of COS-CAT to inhibit digestive enzymes reflects its preventive effect on diabetes mellitus and its complications.

Pseudomonas syringae senses polyphenols via phosphorelay crosstalk to inhibit virulence

Bacteria use a variety of mechanisms, such as two-component regulatory systems (TCSs), to rapidly sense and respond to distinct conditions and signals in their host organisms. For example, a type III secretion system (T3SS) is a key determinant of the virulence of the model plant pathogen Pseudomonas syringae and contains the TCS RhpRS as a key regulator. However, the plant-derived compound targeting RhpRS remains unknown. Here, we report that RhpRS directly interacts with polyphenols and responds by switching off P. syringae T3SS via crosstalk with alternative histidine kinases. We identify three natural polyphenols that induce the expression of the rhpRS operon in an RhpS-dependent manner. The presence of these three specific polyphenols inhibits the phosphatase activity of RhpS, thus suppressing T3SS activation in T3SS-inducing conditions. The Pro40 residue of RhpS is essential to respond to these polyphenols. In addition, three non-cognate histidine kinases cooperatively phosphorylate RhpR and antagonize the rhpS mutant phenotype. This work illustrates that plant polyphenols can directly target P. syringae RhpRS, which results in bacterial virulence being switched off via a phosphorylation-related crosstalk.

Plant Extract of Limonium gmelinii Attenuates Oxidative Responses in Neurons, Astrocytes, and Cerebral Endothelial Cells In Vitro and Improves Motor Functions of Rats after Middle Cerebral Artery Occlusion

There are numerous publications demonstrating that plant polyphenols can reduce oxidative stress and inflammatory processes in the brain. In the present study we have investigated the neuroprotective effect of plant extract isolated from the roots of L. gmelinii since it contains a rich source of polyphenols and other biologically active compounds. We have applied an oxidative and inflammatory model induced by NMDA, H₂O₂, and TNF-α in human primary neurons and astrocytes, and mouse cerebral endothelial cell (CECs) line in vitro. The levels of ROS generation, NADPH oxidase activation, P-selectin expression, and activity of ERK1/2 were evaluated by quantitative immunofluorescence analysis, confocal microscopy, and MAPK assay. In vivo, sensorimotor functions in rats with middle cerebral artery occlusion (MCAO) were assessed. In neurons NMDA induced overproduction of ROS, in astrocytes TNF-α initiated ROS generation, NADPH oxidase activation, and phosphorylation of ERK1/2. In CECs, the exposure by TNF-α induced oxidative stress and triggered the accumulation of P-selectin on the surface of the cells. In turn, pre-treatment of the cells with the extract of L. gmelinii suppressed oxidative stress in all cell types and pro-inflammatory responses in astrocytes and CECs. In vivo, the treatment with L. gmelinii extract improved motor activity in rats with MCAO.

Polyphenolic Antibacterials for Food Preservation: Review, Challenges, and Current Applications

Natural alternatives replacing artificial additives have gained much attention in the consumer’s view because of the growing search for clean label products that are devoid of carcinogenic and toxic effects. Plant polyphenols are considered as suitable alternative natural preservatives with antioxidant and antimicrobial properties. However, their uses in the food industry are undermined by a series of limitations such as low solubility and stability during food processing and storage, lack of standardization, and undesirable organoleptic properties. Different approaches in the use of polyphenols have been proposed in order to overcome the current hurdles related to food preservation. This review article specifically focuses on the antibacterial activity of plant-derived polyphenols as well as their applications as food preservatives, main challenges, and other trends in the food industry.

Phenolic Profile, Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS² and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.

Detection and Imaging of the Plant Pathogen Response by Near-Infrared Fluorescent Polyphenol Sensors

Plants use secondary metabolites such as polyphenols for chemical defense against pathogens and herbivores. Despite their importance in plant pathogen interactions and tolerance to diseases, it remains challenging to detect polyphenols in complex plant tissues. Here, we create molecular sensors for plant polyphenol imaging that are based on near-infrared (NIR) fluorescent single-wall carbon nanotubes (SWCNTs). We identified polyethylene glycol-phospholipids that render (6,5)-SWCNTs sensitive (K_d =90 nM) to plant polyphenols (tannins, flavonoids, …), which red-shift (up to 20 nm) and quench their emission (ca. 1000 nm). These sensors report changes in total polyphenol level after herbivore or pathogen challenge in crop plant systems (Soybean Glycine max) and leaf tissue extracts (Tococa spp.). We furthermore demonstrate remote chemical imaging of pathogen-induced polyphenol release from roots of soybean seedlings over the time course of 24 h. This approach allows in situ visualization and understanding of the chemical plant defense in real time and paves the way for plant phenotyping for optimized polyphenol secretion.

Characterization of Oligomeric Proanthocyanidin-Enriched Fractions from Aronia melanocarpa (Michx.) Elliott via High-Resolution Mass Spectrometry and Investigations on Their Inhibitory Potential on Human Topoisomerases

Aronia melanocarpa (MICHX.) ELLIOTT, which belongs to the Rosaceae family, has increasingly come into focus of research due to the high content of polyphenols. In addition to antioxidative properties, further health-promoting effects of these polyphenols are still of interest. Especially, the proanthocyanidins offer thereby huge opportunities due to their high structural heterogeneity. Therefore, the present study focuses on the topoisomerase inhibiting effects of oligomeric proanthocyanidins (PACs), which are potentially depended on their degree of polymerization. The investigated PACs isolated from Aronia berries were characterized by chromatographic techniques and liquid chromatography-high-resolution mass spectrometry. Four PAC enriched fractions were obtained from Aronia pomace containing 47 PACs with a degree of polymerization from three to six. Due to the low yield of hexamers, the potential inhibiting effects against human topoisomerase were investigated for the trimer to pentamer fractions. The relaxation and decatenation assays were performed to examine the inhibiting effect on topoisomerases under cell-free conditions. Moreover, rapid isolation of topoisomerase cleavage complexes in human colon carcinoma HT29 cells was performed to evaluate the effect on topoisomerases in a cell-based system. The fractions demonstrated inhibitory potential on topoisomerases I and II. In sum, an increasing effect strength depending on the degree of polymerization was shown.

Polyphenol-Hydroxylating Tyrosinase Activity under Acidic pH Enables Efficient Synthesis of Plant Catechols and Gallols

Tyrosinase is generally known as a melanin-forming enzyme, facilitating monooxygenation of phenols, oxidation of catechols into quinones, and finally generating biological melanin. As a homologous form of tyrosinase in plants, plant polyphenol oxidases perform the same oxidation reactions specifically toward plant polyphenols. Recent studies reported synthetic strategies for large scale preparation of hydroxylated plant polyphenols, using bacterial tyrosinases rather than plant polyphenol oxidase or other monooxygenases, by leveraging its robust monophenolase activity and broad substrate specificity. Herein, we report a novel synthesis of functional plant polyphenols, especially quercetin and myricetin from kaempferol, using screened bacterial tyrosinases. The critical bottleneck of the biocatalysis was identified as instability of the catechol and gallol under neutral and basic conditions. To overcome such instability of the products, the tyrosinase reaction proceeded under acidic conditions. Under mild acidic conditions supplemented with reducing agents, a bacterial tyrosinase from Bacillus megaterium (BmTy) displayed efficient consecutive two-step monophenolase activities producing quercetin and myricetin from kaempferol. Furthermore, the broad substrate specificity of BmTy toward diverse polyphenols enabled us to achieve the first biosynthesis of tricetin and 3'-hydroxyeriodictyol from apigenin and naringenin, respectively. These results suggest that microbial tyrosinase is a useful biocatalyst to prepare plant polyphenolic catechols and gallols with high productivity, which were hardly achieved by using other monooxygenases such as cytochrome P450s.

Understanding the Gastrointestinal Protective Effects of Polyphenols using Foodomics-Based Approaches

Plant polyphenols are rich sources of natural anti-oxidants and prebiotics. After ingestion, most polyphenols are absorbed in the intestine and interact with the gut microbiota and modulated metabolites produced by bacterial fermentation, such as short-chain fatty acids (SCFAs). Dietary polyphenols immunomodulatory role by regulating intestinal microorganisms, inhibiting the etiology and pathogenesis of various diseases including colon cancer, colorectal cancer, inflammatory bowel disease (IBD) and colitis. Foodomics is a novel high-throughput analysis approach widely applied in food and nutrition studies, incorporating genomics, transcriptomics, proteomics, metabolomics, and integrating multi-omics technologies. In this review, we present an overview of foodomics technologies for identifying active polyphenol components from natural foods, as well as a summary of the gastrointestinal protective effects of polyphenols based on foodomics approaches. Furthermore, we critically assess the limitations in applying foodomics technologies to investigate the protective effect of polyphenols on the gastrointestinal (GI) system. Finally, we outline future directions of foodomics techniques to investigate GI protective effects of polyphenols. Foodomics based on the combination of several analytical platforms and data processing for genomics, transcriptomics, proteomics and metabolomics studies, provides abundant data and a more comprehensive understanding of the interactions between polyphenols and the GI tract at the molecular level. This contribution provides a basis for further exploring the protective mechanisms of polyphenols on the GI system.

[Microbial synthesis of plant polyphenols]

Plant polyphenols are phenylpropanoid derivatives including phenolic acids, stilbenes, curcumins and flavonoids. These compounds display a variety of biological and pharmacological activities such as antioxidation, vasorelaxation, anti-coagulation, anti-inflammation, anti-tumor and anti-virus, conferring a huge application potential in the sectors of drugs, foods, cosmetics, and chemicals. Microorganisms have become important hosts for heterologous synthesis of natural products due to the advantages of fast growth, easiness of culture and industrial operation. In recent years, the development of synthetic biology has boosted the microbial synthesis of plant natural products, achieving substantial progress. In this review, we summarize the synthesis of plant polyphenols in engineered Escherichia coli, Saccharomyces cerevisiae and other microorganisms equipped with the designed biosynthetic pathways of polyphenols. We also discuss the optimization strategies such as precursor engineering, dynamic regulation, and co-cultivation to improve the production of polyphenols and propose future prospects for polyphenol pathway engineering.

Natural Compound from Olive Oil Inhibits S100A9 Amyloid Formation and Cytotoxicity: Implications for Preventing Alzheimer's Disease

Polyphenolic compounds in the Mediterranean diet have received increasing attention due to their protective properties in amyloid neurodegenerative and many other diseases. Here, we have demonstrated for the first time that polyphenol oleuropein aglycone (OleA), which is the most abundant compound in olive oil, has multiple potencies for the inhibition of amyloid self-assembly of pro-inflammatory protein S100A9 and the mitigation of the damaging effect of its amyloids on neuroblastoma SH-SY5Y cells. OleA directly interacts with both native and fibrillar S100A9 as shown by intrinsic fluorescence and molecular dynamic simulation. OleA prevents S100A9 amyloid oligomerization as shown using amyloid oligomer-specific antibodies and cross-β-sheet formation detected by circular dichroism. It decreases the length of amyloid fibrils measured by atomic force microscopy (AFM) as well as reduces the effective rate of amyloid growth and the overall amyloid load as derived from the kinetic analysis of amyloid formation. OleA disintegrates already preformed fibrils of S100A9, converting them into nonfibrillar and nontoxic aggregates as revealed by amyloid thioflavin-T dye binding, AFM, and cytotoxicity assays. At the cellular level, OleA targets S100A9 amyloids already at the membranes as shown by immunofluorescence and fluorescence resonance energy transfer, significantly reducing the amyloid accumulation in GM1 ganglioside containing membrane rafts. OleA increases overall cell viability when neuroblastoma cells are subjected to the amyloid load and alleviates amyloid-induced intracellular rise of reactive oxidative species and free Ca²⁺. Since S100A9 is both a pro-inflammatory and amyloidogenic protein, OleA may effectively mitigate the pathological consequences of the S100A9-dependent amyloid-neuroinflammatory cascade as well as provide protection from neurodegeneration, if used within the Mediterranean diet as a potential preventive measure.

Dietary Plant Polyphenols: Effects of Food Processing on Their Content and Bioavailability

Dietary plant polyphenols are natural bioactive compounds that are increasingly attracting the attention of food scientists and nutritionists because of their nutraceutical properties. In fact, many studies have shown that polyphenol-rich diets have protective effects against most chronic diseases. However, these health benefits are strongly related to both polyphenol content and bioavailability, which in turn depend on their origin, food matrix, processing, digestion, and cellular metabolism. Although most fruits and vegetables are valuable sources of polyphenols, they are not usually consumed raw. Instead, they go through some processing steps, either industrially or domestically (e.g., cooling, heating, drying, fermentation, etc.), that affect their content, bioaccessibility, and bioavailability. This review summarizes the status of knowledge on the possible (positive or negative) effects of commonly used food-processing techniques on phenolic compound content and bioavailability in fruits and vegetables. These effects depend on the plant type and applied processing parameters (type, duration, media, and intensity). This review attempts to shed light on the importance of more comprehensive dietary guidelines that consider the recommendations of processing parameters to take full advantage of phenolic compounds toward healthier foods.

Antioxidant and reduced skin-ageing effects of a polyphenol-enriched dietary supplement in response to air pollution: a randomized, double-blind, placebo-controlled study

Background

Air pollution exposure is one of the major threats to skin health and accelerates skin ageing mainly through oxidative stress mechanisms. Since it is difficult to minimize skin exposure to air pollutants, especially in urban areas, strategies to protect the skin are needed. Plant phenolic compounds have been found to be effective in attenuating cellular oxidative stress and inflammation induced by different air pollutants and a dietary approach based on these compounds could provide an efficient protection measure.

Objective

Here we investigated the efficacy of a commercially available polyphenol-enriched dietary supplement (Zeropollution^®) in reducing pollution-induced oxidative stress and in improving different skin parameters related to skin ageing of Caucasian and Asian subjects exposed to air pollution. Zeropollution is composed of four standardized herbal extracts: Olea europaea leaf, Lippia citriodora, Rosmarinus officinalis, and Sophora japonica.

Design

A double-blind randomized, parallel group study was carried out on 100 outdoor workers living in a polluted urban European area (Milan) to assess the efficacy of the dietary supplement. The total antioxidant capacity on saliva (FRAP), the oxidative damage on skin (lipoperoxides content), skin moisturization (corneometer), transepidermal water loss (tewameter), skin radiance and colour (spectrophotometer), skin elasticity (cutometer), skin sebum content (sebumeter), and the skin roughness (image analysis) were measured.

Results

Both inter-group and intra-group analysis proved that the dietary supplement improved all clinical and biochemical-monitored parameters, in both Caucasian and Asian individuals. Some of the positive effects such as decreased wrinkle depth, increased elasticity and firmness, improved skin moisturization and transepidermal water loss, and reduced dark spots pigmentation were statistically significant as early as 2 weeks of product consumption.

Conclusions

The results of the study indicate reduced oxidative stress-induced skin damage in both Asian and Caucasian women living in a polluted urban area. Therefore, the oral intake of this four-plant based supplement could be considered a complementary nutrition strategy to avoid the negative effects of environmental pollution exposure.

Curcumin, Quercetin, Catechins and Metabolic Diseases: The Role of Gut Microbiota

Polyphenols (PPs) are the naturally occurring bioactive components in fruits and vegetables, and they are the most abundant antioxidant in the human diet. Studies are suggesting that ingestion of PPs might be helpful to ameliorate metabolic syndromes that may contribute in the prevention of several chronic disorders like diabetes, obesity, hypertension, and colon cancer. PPs have structural diversity which impacts their bioavailability as they accumulate in the large intestine and are extensively metabolized through gut microbiota (GM). Intestinal microbiota transforms PPs into their metabolites to make them bioactive. Interestingly, not only GM act on PPs to metabolize them but PPs also modulate the composition of GM. Thus, change in GM from pathogenic to beneficial ones may be helpful to ameliorate gut health and associated diseases. However, to overcome the low bioavailability of PPs, various approaches have been developed to improve their solubility and transportation through the gut. In this review, we present evidence supporting the structural changes that occur after metabolic reactions in PPs (curcumin, quercetin, and catechins) and their effect on GM composition that leads to improving overall gut health and helping to ameliorate metabolic disorders.

Effects of Long-Term Supplementation with Brown Seaweeds and Polyphenols in Rabbit on Meat Quality Parameters

The objective of the present study was to evaluate the effects of dam and offspring dietary supplementation with a natural feed additive on the growth performance and meat quality parameters of growing rabbits. The growing rabbits are selected from lactating does receiving a control diet (C) or diets supplemented with 0.3% (SP1) and 0.6% (SP2) of feed additive containing brown seaweeds (Laminaria spp.) and plant extracts. In the postweaning phase, the growing rabbits remained in the treatment group defined by their does and the trial lasted 42 days. The average daily feed intake and feed conversion ratio were improved in the rabbit fed 0.6% of the natural feed additive. The cholesterol content tended to be lower in Longissimus lumborum (LL) muscle and decrease in Semimembranosus (SM) muscle (in SP2 -41.36% than controls). The α tocopherol and retinol content were enhanced in both muscles of rabbit fed the natural mixture (SP1 and SP2 groups). An improvement of sensory attributes of texture was observed in both muscles from rabbit fed natural mixture. In conclusion, long term supplementation of both lactating does and offspring with the high dosage of brown seaweed and plant polyphenols improves growth performance and enhances meat nutritional and sensory parameters.

Therapy-related acute myeloid leukemia and its prevention

BACKGROUND

Secondary tumors, including therapy-related acute myeloid leukemia (t-AML), represent one of the most undesirable side effects of chemotherapy, which arise several years after primary cancer treatment. This review aims to analyze the current data on molecular pathogenesis of t-AML revealing potential criteria for predicting predisposition to the disease. Another objective is to analyze the information on promising approaches for t-AML prevention.

METHODS

We analyzed studies regarding t-AML and possible approaches for cancer prevention of drug-induced tumors. Publications in the databases, such as SciVerse Scopus (948), PubMed (1837) and Web of Science (935) were used. Among 92 the most important publications cited in the review, 79 were published during the last decade.

RESULTS

The review provides the information concerning t-AML pathogenesis, molecular markers of primary cancer patients with high risk of t-AML. The role of the bone marrow niche in clonal hematopoiesis and t-AML pathogenesis is discussed. Current approaches for t-AML prevention both at the stage of therapy and at the latent period are described. Inhibition effects of polyphenols on cell proliferation and on the appearance of hemopoetic clones of indeterminate potential are proposed for t-AML prevention.

CONCLUSION

The problem of the t-AML, a cancer induced by genotoxic chemotherapeutic drugs, is considered from the point of view of the fundamental mechanisms of chemical carcinogenesis, highlighting initiation and promotion stages. It enables to reveal the possible markers for the group of patients with high risk for t-AML and to demonstrate perspectives for the use of plant polyphenols for t-AML prevention.

Plant Polyphenols-Biofortified Foods as a Novel Tool for the Prevention of Human Gut Diseases

Plant food biofortification is recently receiving remarkable attention, as it aims to increase the intake of minerals, vitamins, or antioxidants, crucial for their contribution to the general human health status and disease prevention. In this context, the study of the plant’s secondary metabolites, such as polyphenols, plays a pivotal role for the development of a new generation of plant crops, compensating, at least in part, the low nutritional quality of Western diets with a higher quality of dietary sources. Due to the prevalent immunomodulatory activity at the intestinal level, polyphenols represent a nutritionally relevant class of plant secondary metabolites. In this review, we focus on the antioxidant and anti-inflammatory properties of different classes of polyphenols with a specific attention to their potential in the prevention of intestinal pathological processes. We also discuss the latest biotechnology strategies and new advances of genomic techniques as a helpful tool for polyphenols biofortification and the development of novel, healthy dietary alternatives that can contribute to the prevention of inflammatory bowel diseases.

Biomass-Derived Multilayer-Structured Microparticles for Accelerated Hemostasis and Bone Repair

It is very desirable to develop advanced sustainable biomedical materials with superior biosafety and bioactivity for clinical applications. Herein, biomass-derived multilayer-structured absorbable microparticles (MQ x T y ) composed of starches and plant polyphenols are readily constructed for the safe and effective treatment of bone defects with intractable bleeding by coating multiple layers of quaternized starch (Q+) and tannic acid onto microporous starch microparticles via facile layer-by-layer assembly. MQ x T y microparticles exhibit efficient degradability, low cytotoxicity, and good blood compatibility. Among various MQ x T y microparticles with distinct Q+/T- double layers, MQ2T2 with outmost polyphenol layer possess the unique properties of platelet adhesion/activation and red blood cell aggregation, resulting in the best hemostatic performance. In a mouse cancellous-bone-defect model, MQ2T2 exhibits the favorable hemostatic effect, low inflammation/immune responses, high biodegradability, and promoted bone repair. A proof-of-concept study of beagles further confirms the good performance of MQ2T2 in controlling intractable bleeding of bone defects. The present work demonstrates that such biomass-based multilayer-structured microparticles are very promising biomedical materials for clinical use.

Polyphenols in Farm Animals: Source of Reproductive Gain or Waste?

Reproduction is a complex process that is substantially affected by environmental cues, specifically feed/diet and its components. Farm animals as herbivorous animals are exposed to a large amount of polyphenols present in their natural feeding system, in alternative feed resources (shrubs, trees, and agro-industrial byproducts), and in polyphenol-enriched additives. Such exposure has increased because of the well-known antioxidant properties of polyphenols. However, to date, the argumentation around the impacts of polyphenols on reproductive events is debatable. Accordingly, the intensive inclusion of polyphenols in the diets of breeding animals and in media for assisted reproductive techniques needs further investigation, avoiding any source of reproductive waste and achieving maximum benefits. This review illustrates recent findings connecting dietary polyphenols consumption from different sources (conventional and unconventional feeds) with the reproductive performance of farm animals, underpinned by the findings of in vitro studies in this field. This update will help in formulating proper diets, optimizing the introduction of new plant species, and feed additives for improving reproductive function, avoiding possible reproductive wastes and maximizing possible benefits.

Antimicrobial Capacity of Plant Polyphenols against Gram-positive Bacteria: A Comprehensive Review

BACKGROUND

Multi-drug-resistant bacteria such as Methicillin-Resistant Staphylococcus aureus (MRSA) disseminate rapidly amongst patients in healthcare facilities and suppose an increasingly important cause of community-associated infections and associated mortality. The development of effective therapeutic options against resistant bacteria is a public health priority. Plant polyphenols are structurally diverse compounds that have been used for centuries for medicinal purposes, including infections treatment and possess, not only antimicrobial activity, but also antioxidant, anti-inflammatory and anticancer activities among others. Based on the existing evidence on the polyphenols' antibacterial capacity, polyphenols may be postulated as an alternative or complementary therapy for infectious diseases.

OBJECTIVE

To review the antimicrobial activity of plant polyphenols against Gram-positive bacteria, especially against S. aureus and its resistant strains. Determine the main bacterial molecular targets of polyphenols and their potential mechanism of action.

METHODOLOGY

The most relevant reports on plant polyphenols' antibacterial activity and their putative molecular targets were studied. We also performed virtual screening of thousand different polyphenols against proteins involved in the peptidoglycan biosynthesis to find potential valuable bioactive compounds. The bibliographic information used in this review was obtained from MEDLINE via PubMed.

RESULTS

Several polyphenols: phenolic acids, flavonoids (especially flavonols), tannins, lignans, stilbenes and combinations of these in botanical mixtures, have exhibited significant antibacterial activity against resistant and non-resistant Gram-positive bacteria at low μg/mL range MIC values. Their mechanism of action is quite diverse, targeting cell wall, lipid membrane, membrane receptors and ion channels, bacteria metabolites and biofilm formation. Synergic effects were also demonstrated for some combinations of polyphenols and antibiotics.

CONCLUSION

Plant polyphenols mean a promising source of antibacterial agents, either alone or in combination with existing antibiotics, for the development of new antibiotic therapies.

Healthy Effects of Plant Polyphenols: Molecular Mechanisms

The increasing extension in life expectancy of human beings in developed countries is accompanied by a progressively greater rate of degenerative diseases associated with lifestyle and aging, most of which are still waiting for effective, not merely symptomatic, therapies. Accordingly, at present, the recommendations aimed at reducing the prevalence of these conditions in the population are limited to a safer lifestyle including physical/mental exercise, a reduced caloric intake, and a proper diet in a convivial environment. The claimed health benefits of the Mediterranean and Asian diets have been confirmed in many clinical trials and epidemiological surveys. These diets are characterized by several features, including low meat consumption, the intake of oils instead of fats as lipid sources, moderate amounts of red wine, and significant amounts of fresh fruit and vegetables. In particular, the latter have attracted popular and scientific attention for their content, though in reduced amounts, of a number of molecules increasingly investigated for their healthy properties. Among the latter, plant polyphenols have raised remarkable interest in the scientific community; in fact, several clinical trials have confirmed that many health benefits of the Mediterranean/Asian diets can be traced back to the presence of significant amounts of these molecules, even though, in some cases, contradictory results have been reported, which highlights the need for further investigation. In light of the results of these trials, recent research has sought to provide information on the biochemical, molecular, epigenetic, and cell biology modifications by plant polyphenols in cell, organismal, animal, and human models of cancer, metabolic, and neurodegenerative pathologies, notably Alzheimer's and Parkinson disease. The findings reported in the last decade are starting to help to decipher the complex relations between plant polyphenols and cell homeostatic systems including metabolic and redox equilibrium, proteostasis, and the inflammatory response, establishing an increasingly solid molecular basis for the healthy effects of these molecules. Taken together, the data currently available, though still incomplete, are providing a rationale for the possible use of natural polyphenols, or their molecular scaffolds, as nutraceuticals to contrast aging and to combat many associated pathologies.

Universal Nature-Inspired and Amine-Promoted Metallization for Flexible Electronics and Supercapacitors

Economical and abundant natural biological materials provide a low-cost and scalable approach to develop next-generation flexible and wearable electronics. Herein, a universal strategy of nature-inspired and amine-promoted metallization, namely, NIAPM, is presented to make high-quality metals for electronics fabrication. The introduction of poly(ethyleneimine) (PEI) significantly shortens the time of metallization from >48 h to ≈6 h, and the phenol compounds (TP) from green tea make metals bond tightly on all demonstrated surfaces. The as-made thin metal films of Cu and Ni feature high conductivity (∼1.0 Ω/□), excellent mechanical stability and flexibility even at the bending radius of ∼1 mm. Moreover, NIAPM is compatible with typical lithography techniques for fabricating metallic patterns, showing considerable potential applications in flexible electronics. As a proof-of-concept, two devices based on melamine-templated Cu sponges are first prepared for detecting the change of external pressure with a resistance sensitivity of 18.1 kPa^-1 and collecting high-viscosity crude oil, respectively. Then, a high-performance bendable solid supercapacitor is demonstrated using as-prepared Ni metallized fabrics and the activated porous carbon from the recycled waste in NIPAM as flexible electrodes, which possesses comparable areal capacitance of 45.5 F·g^-1, and energy density of 7.88 Wh·g^-1 at the power density of 35 W·g^-1. Therefore, it is anticipated that such a time-saving, cost-effective and whole solution-processed NIAPM strategy can inspire further practical applications in the fields of surface chemistry, material science, flexible and wearable electronics, etc.

Study of SH-SY5Y Cancer Cell Response to Treatment with Polyphenol Extracts Using FT-IR Spectroscopy

Plant polyphenols are important components of human diet and a number of them are considered to possess chemo-preventive and therapeutic properties against cancer. They are recognized as naturally occurring antioxidants, but also as pro-oxidant, pro-apoptotic, or chromosomal aberrations inducers, depending on their concentration and/or the stage of cell-cycle of the cells with which they interact. For these reasons, particular interest is devoted to knowing the total effects of polyphenols on the cell cycle and metabolism. Fourier-Transform Infrared (FT-IR) spectroscopy thanks to its ability in analyzing cells at a molecular level can be particularly useful in investigating the biochemical changes induced in protein, nucleic acid, lipid, and carbohydrate content of cells by means of polyphenols administration. Spectroscopic analysis was performed on in vitro human SH-SY5Y neuroblastoma cells that were exposed to different doses of a cherry derived polyphenol extract. The infrared spectra that were obtained from unexposed and exposed cells show significant differences that can be helpful in order to understand the cells-polyphenols interaction.

Plant Polyphenols and Exendin-4 Prevent Hyperactivity and TNF-α Release in LPS-Treated In vitro Neuron/Astrocyte/Microglial Networks

Increasing evidence supports a decisive role for neuroinflammation in the neurodegenerative process of several central nervous system (CNS) disorders. Microglia are essential mediators of neuroinflammation and can regulate a broad spectrum of cellular responses by releasing reactive oxygen intermediates, nitric oxide, proteases, excitatory amino acids, and cytokines. We have recently shown that also in ex-vivo cortical networks of neurons, astrocytes and microglia, an increased level of tumor necrosis factor-alpha (TNF-α) was detected a few hours after exposure to the bacterial endotoxin lipopolysaccharide (LPS). Simultaneously, an atypical “seizure-like” neuronal network activity was recorded by multi-electrode array (MEA) electrophysiology. These effects were prevented by minocycline, an established anti-inflammatory antibiotic. We show here that the same inhibitory effect against LPS-induced neuroinflammation is exerted also by natural plant compounds, polyphenols, such as curcumin (CU, curcuma longa), crocin (CR, saffron), and resveratrol (RE, grape), as well as by the glucagon like peptide-1 receptor (GLP-1R) agonist exendin-4 (EX-4). The drugs tested also caused per-se early transient (variable) changes of network activity. Since it has been reported that LPS-induced neuroinflammation causes rearrangements of glutamate transporters in astrocytes and microglia, we suggest that neural activity could be putatively increased by an imbalance of glial glutamate transporter activity, leading to prolonged synaptic glutamatergic dysregulation.

Natural Substances for Prevention of Skin Photoaging: Screening Systems in the Development of Sunscreen and Rejuvenation Cosmetics

Solar broadband UV irradiation is commonly regarded as a major causative reason for cutaneous photoaging. The pro-aging molecular pathways and cellular targets affected by UVA+UVB light in human skin have been extensively investigated. Notwithstanding growing knowledge in mechanisms of photoaging, research and development of clinically efficient, nontoxic, and sustainable topical preparations providing full physical, chemical, and biological photoprotection still remain a great challenge for pharmaceutical and cosmetic industries. In this study, we are proposing a panel of the in vitro methods for preselection of natural photoprotective substances with high photostability and low phototoxicity able of absorbing a broadband UVA+UVB irradiation (physical sunscreen), reducing UV-related overproduction of free radicals and loss of endogenous antioxidants (chemical protection), and attenuating UV-induced cytotoxicity and immune and metabolic responses (biological protection) in primary human epidermal keratinocytes and immortalized human keratinocyte cultures. Our data showed that secondary metabolites biosynthesized in plant cells in response to UV irradiation, such as phenylpropanoids and their glycosylated metabolites, aglycons and glycosylated flavonoids, and leontopodic acids, hold the best promise for complete natural topical prevention of photoaging and rejuvenation of photoaged skin. Meristem plant cell cultures elicited by solar simulating UV could be the most environmentally sustainable biotechnological source of polyphenols with combined photoprotective and antiaging properties.

Control of Maillard Reactions in Foods: Strategies and Chemical Mechanisms

Maillard reactions lead to changes in food color, organoleptic properties, protein functionality, and protein digestibility. Numerous different strategies for controlling Maillard reactions in foods have been attempted during the past decades. In this paper, recent advances in strategies for controlling the Maillard reaction and subsequent downstream reaction products in food systems are critically reviewed. The underlying mechanisms at play are presented, strengths and weaknesses of each strategy are discussed, and reasonable reaction mechanisms are proposed to reinforce the evaluations. The review includes strategies involving addition of functional ingredients, such as plant polyphenols and vitamins, as well as enzymes. The resulting trapping or modification of Maillard targets, reactive intermediates, and advanced glycation endproducts (AGEs) are presented with their potential unwanted side effects. Finally, recent advances in processing for control of Maillard reactions are discussed.

Antibiofilm Activity of Plant Polyphenols

In the history of human medicine, antibiotics represent epochal examples of medical progress. However, with an approaching antibiotic crisis due to the emergence and extensive spread of antimicrobial resistance among bacterial agents, as well as to increasing number of patients with chronic and recalcitrant bacterial biofilm-associated infections, the naturally occurring molecules may become new sources of antibacterial and antibiofilm drugs for clinical usage. Polyphenols represent a class of plant natural products which are important in plant defense against microbial pathogens. The main focus of the review is on the antibiofilm activities of phenolic compounds against bacteria which play an essential role in medical device biofilm-associated infections. The other, not negligible part of the review is devoted to polyphenols’ activity against bacterial agents that cause dental caries and periodontal disease.

Antioxidant activity of commercial food grade tannins exemplified in a wine model

Although commercial tannins are widely used in foods and beverages, an improved understanding of the structure and composition of vegetable tannins is needed to promote the exploitation of agri-food by-products and waste and their valorisation in more sustainable industrial applications. This study aims to characterise the phytochemical composition and antioxidant activity of 13 food grade tannins using multiple analytical approaches, including spectrophotometry and HPLC-ECD to determine the amount of targeted polyphenolic compounds. Moreover, the antioxidant activity of tannins was assessed in terms of radical scavenging activity (DPPH• assay), reducing power (FRAP assay), and redox properties (cyclic voltammetry, CV). A statistical univariate and multivariate correlation analysis was performed on 17 parameters including tannin content (range: 0.71-1.62 mM), gallic acid, (+)-catechin, syringic acid and (‒)-epicatechin. The compositional profile of tannins was related to their chemical moiety, antioxidant activity and the botanical origin of the extracts. In particular, the CV signal at 500 mV was highly correlated with DPPH• value due to the catechol ring of flavonoids and trigalloyl moieties of gallic acid-based compounds. Practical examples of tannins application in winemaking are discussed.

Antioxidant, Antinociceptive and CNS Activities of Viscum orientale and High Sensitive Quantification of Bioactive Polyphenols by UPLC

Viscum orientale Willd. (Loranthaceae) has long been used in traditional medicine to treat pain, neuropharmacological disorders and various forms of tumor but not yet been reported. The aim of this study is to rationalize the traditional medicinal use of this plant by evaluating the methanol extract of V. orientale leaves (MEVOL) for anti-nociceptive, CNS depressant and antioxidant activities and to quantify the bioactive polyphenols present in this plant. Five polyphenolic compounds namely gallic acid, vanillic acid, caffeic acid, ellagic acid, and quercetin (17.54, 8.99, 99.61, 4523.31, and 100.15 mg/100 g of dry weight, respectively) have been identified in MEVOL using Ultra Performance Liquid Chromatography. Qualitative antioxidant activity determined by Thin Layer Chromatography indicated the presence of antioxidants. In quantitative antioxidant test using 2,2-diphenyl 1-picrylhydrazyl, MEVOL exhibited strong free antioxidant activity in a dose dependant manner (IC₅₀ = 6.63 μg/ml) compared with ascorbic acid (IC₅₀ = 1.91 μg/ml) and butylatedhydroxyanisole (IC₅₀ = 2.27 μg/ml) controls. Total phenolic content determined using Folin Ciocaltu reagent was found to be 73.4 mg gallic acid equivalent/g of extract, while flavonoid content estimated using aluminum chloride colorimetric method was 170.7 mg quercetin equivalent/g of extract. Anti-nociceptive activity of MEVOL measured using acetic acid and formalin induced pain models in mice was significant (p < 0.001). MEVOL showed 65.6 and 88.8% writhing inhibition at 300 and 500 mg/kg body weight, respectively, comparing with standard diclofenac-Na (75.2% inhibition) at 25 mg/kg body weight in acetic acid induced pain model. In formalin induced pain model, paw licking was inhibited 45.93 and 56.4% in early phase and 55.66 and 72.64% in late phase at 300 and 500 mg/kg body weight, respectively, while diclofenac-Na inhibited 60.47 and 61.32% in early and late phase at 10 mg/kg body weight, respectively. In neuropharmacological activity test, overall behavioral test significantly reinforced CNS depressant activity. Spontaneous motor activities were reduced (p < 0.05) in both hole cross and open field tests compared with diazepam. Antioxidant activity of MEVOL is likely due to the phenolic and flavonoid compounds present within the leaf tissues. This study reveals significant in vivo anti-nociceptive and CNS depressant activities which justifies traditional medicinal applications of V. orientale.

An Approach Based on HPLC-Fingerprint and Chemometrics to Quality Consistency Evaluation of Matricaria chamomilla L. Commercial Samples

Chamomile has been used as an herbal medication since ancient times and is still popular because it contains various bioactive phytochemicals that could provide therapeutic effects. In this study, a simple and reliable HPLC method was developed to evaluate the quality consistency of nineteen chamomile samples through establishing a chromatographic fingerprint, quantification of phenolic compounds and determination of antioxidant activity. For fingerprint analysis, 12 peaks were selected as the common peaks to evaluate the similarities of commercial samples of chamomile obtained from different manufacturers. A similarity analysis was performed to assess the similarity/dissimilarity of chamomile samples where values varied from 0.868 to 0.990 what indicating that samples from different manufacturers were consistent. Additionally, simultaneous quantification of five phenolic acids (gallic, caffeic, syringic, p-coumaric, ferulic) and four flavonoids (rutin, myricetin, quercetin and keampferol) was performed to interpret the quality consistency. In quantitative analysis, the nine individual phenolic compounds showed good regression (r > 0.9975). Inter- and intra-day precisions for all analyzed compounds expressed as relative standard deviation (CV) ranged from 0.05% to 3.12%. Since flavonoids and other polyphenols are commonly recognized as natural antioxidants, the antioxidant activity of chamomile samples was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) assay. Correlation analysis was used to assess the relationship between antioxidant activity and phenolic composition, and multivariate analysis (PCA and HCA) were applied to distinguish chamomile samples. Results shown in the study indicate high similarity of chamomile samples among them, widely spread in the market and commonly used by people as infusions or teas, as well as that there were no statistically significant differences among them, which in turn is a proof of high quality of commercially available samples of chamomile. The study indicated that the combination of chromatographic fingerprint and quantitative analysis can be readily utilized as a quality consistency method for chamomile and related medicinal preparations. Moreover, the applied strategy seems to be the most promising for the assessment of the investigated plant material.

Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR]), concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid), total plasma polyphenols, ferric reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and activities of creatine kinase (CK) and lactate dehydrogenase (LDH) as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions) were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement.

Resveratrol and para-coumarate serve as ring precursors for coenzyme Q biosynthesis

Coenzyme Q (Q or ubiquinone) is a redox-active polyisoprenylated benzoquinone lipid essential for electron and proton transport in the mitochondrial respiratory chain. The aromatic ring 4-hydroxybenzoic acid (4HB) is commonly depicted as the sole aromatic ring precursor in Q biosynthesis despite the recent finding that para-aminobenzoic acid (pABA) also serves as a ring precursor in Saccharomyces cerevisiae Q biosynthesis. In this study, we employed aromatic (13)C6-ring-labeled compounds including (13)C6-4HB, (13)C6-pABA, (13)C6-resveratrol, and (13)C6-coumarate to investigate the role of these small molecules as aromatic ring precursors in Q biosynthesis in Escherichia coli, S. cerevisiae, and human and mouse cells. In contrast to S. cerevisiae, neither E. coli nor the mammalian cells tested were able to form (13)C6-Q when cultured in the presence of (13)C6-pABA. However, E. coli cells treated with (13)C6-pABA generated (13)C6-ring-labeled forms of 3-octaprenyl-4-aminobenzoic acid, 2-octaprenyl-aniline, and 3-octaprenyl-2-aminophenol, suggesting UbiA, UbiD, UbiX, and UbiI are capable of using pABA or pABA-derived intermediates as substrates. E. coli, S. cerevisiae, and human and mouse cells cultured in the presence of (13)C6-resveratrol or (13)C6-coumarate were able to synthesize (13)C6-Q. Future evaluation of the physiological and pharmacological responses to dietary polyphenols should consider their metabolism to Q.

Interaction between plant polyphenols and the erythrocyte membrane

The purpose of these studies was to determine the effect of polyphenols contained in extracts from apple, strawberry and blackcurrant on the properties of the erythrocyte membrane, treated as a model of the biological membrane. To this end, the effect of the substances used on hemolysis, osmotic resistance and shape of erythrocytes, and on packing order in the hydrophilic region of the erythrocyte membrane was studied. The investigation was performed with spectrophotometric and fluorimetric methods, and using the optical microscope. The hemolytic studies have shown that the extracts do not induce hemolysis at the concentrations used. The results obtained from the spectrophotometric measurements of osmotic resistance of erythrocytes showed that the polyphenols contained in the extracts cause an increase in the resistance, rendering them less prone to hemolysis in hypotonic solutions of sodium chloride. The fluorimetric studies indicate that the used substances cause a decrease of packing order in the hydrophilic area of membrane lipids. The observations of erythrocyte shapes in a biological optical microscope have shown that, as a result of the substances' action, the erythrocytes become mostly echinocytes, which means that the polyphenols of the extracts localize in the outer lipid monolayer of the erythrocyte membrane. The results obtained indicate that, in the concentration range used, the plant extracts are incorporated into the hydrophilic area of the membrane, modifying its properties.

EXTRACELLULAR ENZYMES OF THE MICROCYSTIS AERUGINOSA PCC 7813 STRAIN ARE INHIBITED IN THE PRESENCE OF HYDROQUINONE AND PYROGALLOL, ALLELOCHEMICALS PRODUCED BY AQUATIC PLANTS(1)

Several cyanobacterial species have a high potential to dominate in marine environments and freshwater reservoirs, and the ecological and physiological reasons for this phenomenon are not understood comprehensively. In this study, the ability of a Microcystis aeruginosa Kütz. strain to produce free dissolved enzymes was documented. We have observed that this highly toxic strain releases alkaline phosphatase, leucine aminopeptidase, and β-glucosidase into the ambient environment. Additionally, the inhibitory activity of selected phenols produced by aquatic plants on the activity of these enzymes was analyzed. The investigated compounds, pyrogallol and, to a lesser degree, hydroquinone, decreased the activity of extracellular enzymes produced by M. aeruginosa, with leucine aminopeptidase being the most sensitive to the inhibitors. The noncompetitive character of enzymatic inhibition suggests that the polyphenols produced by aquatic plants are able to influence the activity of different extracellular or membrane-bound enzymes.

Multifactorial nature of hepatocellular carcinoma drug resistance: could plant polyphenols be helpful?

Primary hepatocellular carcinoma (HCC) is a quite frequent tumor which results in high mortality and most often exhibits a poor response to present drug therapies. Clearly, a thorough understanding of the biological bases of this malignancy might suggest new strategies for its treatment. Here we examine the evidences that both "pharmacological" mechanisms (e.g. drug transporter or detoxification enzyme over-expression) and alterations in other critical factors, including the IAPs (Inhibitory of Apoptosis Proteins), involved in enhancement of cell survival and proliferation may determine the therapeutic resistance of HCC; we also underline the possible role in the process of the activation of transcription factors, like NF-kappaB, capable of contemporaneously up-regulating the mechanisms discussed. On this basis, we finally comment on the possible use of natural multi-targeted antitumoral agents like plant polyphenols to achieve sensitization to treatments in HCC.