Nutraceutical polyphenols: New analytical challenges and opportunities

Characterization of Novel Synthetic Polyphenols: Validation of Antioxidant and Vasculoprotective Activities

Antioxidant compounds, including polyphenols, have therapeutic effects because of their anti-inflammatory, antihypertensive, antithrombotic and antiproliferative properties. They play important roles in protecting the cardiovascular and neurological systems, by having preventive or protective effects against free radicals produced by either normal or pathological metabolism in such systems. For instance, resveratrol, a well-known potent antioxidant, has a counteracting effect on the excess of reactive oxygen species (ROS) and has a number of therapeutic benefits, like anti-inflammatory, anti-cancer and cardioprotective activities. Based on previous work from our group, and on the most frequent OH substitutions of natural polyphenols, we designed two series of synthetically accessible bis-polyhydroxyphenyl derivatives, separated by amide or urea linkers. These compounds exhibit high antioxidant ability (oxygen radical absorbance capacity (ORAC) assay) and interesting radical scavenging activity (RSA) values (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and α,α-diphenyl-β-picrylhydrazyl (DPPH) tests). Some of the best polyphenols were evaluated in two biological systems, endothelial cells (in vitro) and whole aorta (ex vivo), highly susceptible for the deleterious effects of prooxidants under different inflammatory conditions, showing protection against oxidative stress induced by inflammatory stimuli relevant in cardiovascular diseases, i.e., Angiotensin II and IL-1β. Selected compounds also showed strong in vivo antioxidant properties when evaluated in the model organism Saccharomyces cerevisiae.

A Cup of Hemp Coffee by Moka Pot from Southern Italy: An UHPLC-HRMS Investigation

After a long period defined by prohibition of hemp production, this crop has been recently re-evaluated in various industrial sectors. Until now, inflorescences have been considered a processing by-product, not useful for the food industry, and their disposal also represents an economic problem for farmers. The objects of the present work are coffee blends enriched with shredded inflorescences of different cultivars of industrial hemp that underwent solid/liquid extraction into the Italian “moka” coffee maker. The obtained coffee drinks were analyzed by Ultra-High-Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS) tools for their quali-quantitative phytocannabinoid profiles. The results showed that they are minor constituents compared to chlorogenic acids and caffeine in all samples. In particular, cannabidiolic acid was the most abundant among phytocannabinoids, followed by tetrahydrocannabinolic acid. Neither Δ⁹-tetrahydrocannabinol (THC) nor cannabinol, its main oxidation product, were detected. The percentage of total THC never exceeded 0.04%, corresponding to 0.4 mg/kg, far below the current maximum limits imposed by the Italian Ministry of Health. This study opens up a new concrete possibility to exploit hemp processing by-products in order to obtain drinks with high added value and paves the way for further in vitro and in vivo investigations aimed at promoting their benefits for human health.

Polyphenols as Potential Agents in the Management of Temporomandibular Disorders

Temporomandibular disorders (TMD) consist of multifactorial musculoskeletal disorders associated with the muscles of mastication, temporomandibular joint (TMJ), and annexed structures. This clinical condition is characterized by temporomandibular pain, restricted mandibular movement, and TMJ synovial inflammation, resulting in reduced quality of life of affected people. Commonly, TMD management aims to reduce pain and inflammation by using pharmacologic therapies that show efficacy in pain relief but their long-term use is frequently associated with adverse effects. For this reason, the use of natural compounds as an effective alternative to conventional drugs appears extremely interesting. Indeed, polyphenols could represent a potential therapeutic strategy, related to their ability to modulate the inflammatory responses involved in TMD. The present work reviews the mechanisms underlying inflammation-related TMD, highlighting the potential role of polyphenols as a promising approach to develop innovative management of temporomandibular diseases.

Antioxidant Properties of Agri-food Byproducts |and Specific Boosting Effects of Hydrolytic Treatments

Largely produced agri-food byproducts represent a sustainable and easily available source of phenolic compounds, such as lignins and tannins, endowed with potent antioxidant properties. We report herein the characterization of the antioxidant properties of nine plant-derived byproducts. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated the superior activity of pomegranate peels and seeds, grape pomace and pecan nut shell. An increase in the antioxidant potency was observed for most of the waste materials following a hydrolytic treatment, with the exception of the condensed tannin-rich pecan nut shell and grape pomace. UV-Vis and HPLC investigation of the soluble fractions coupled with the results from IR analysis and chemical degradation approaches on the whole materials allowed to conclude that the improvement of the antioxidant properties was due not only to removal of non-active components (mainly carbohydrates), but also to structural modifications of the phenolic compounds. Parallel experiments run on natural and bioinspired model phenolic polymers suggested that these structural modifications positively impacted on the antioxidant properties of lignins and hydrolyzable tannins, whereas significant degradation of condensed tannin moieties occurred, likely responsible for the lowering of the reducing power observed for grape pomace and pecan nut shell. These results open new perspectives toward the exploitation and manipulation of agri-food byproducts for application as antioxidant additives in functional materials.

Natural Phenolic Compounds for Health, Food and Cosmetic Applications

Based on their potent antioxidant properties, natural phenolic compounds have gained more and more attention for their possible exploitation as food supplements, as well as functional ingredients in food and in the cosmetic industry [...].

Bioactive Phenolic Compounds From Agri-Food Wastes: An Update on Green and Sustainable Extraction Methodologies

Phenolic compounds are broadly represented in plant kingdom, and their occurrence in easily accessible low-cost sources like wastes from agri-food processing have led in the last decade to an increase of interest in their recovery and further exploitation. Indeed, most of these compounds are endowed with beneficial properties to human health (e.g., in the prevention of cancer and cardiovascular diseases), that may be largely ascribed to their potent antioxidant and scavenging activity against reactive oxygen species generated in settings of oxidative stress and responsible for the onset of several inflammatory and degenerative diseases. Apart from their use as food supplements or as additives in functional foods, natural phenolic compounds have become increasingly attractive also from a technological point of view, due to their possible exploitation in materials science. Several extraction methodologies have been reported for the recovery of phenolic compounds from agri-food wastes mostly based on the use of organic solvents such as methanol, ethanol, or acetone. However, there is an increasing need for green and sustainable approaches leading to phenolic-rich extracts with low environmental impact. This review addresses the most promising and innovative methodologies for the recovery of functional phenolic compounds from waste materials that have appeared in the recent literature. In particular, extraction procedures based on the use of green technologies (supercritical fluid, microwaves, ultrasounds) as well as of green solvents such as deep eutectic solvents (DES) are surveyed.

Pecan (Carya illinoinensis (Wagenh.) K. Koch) Nut Shell as an Accessible Polyphenol Source for Active Packaging and Food Colorant Stabilization

Herein, the antioxidant and food stabilizing properties of a pecan nut shell (PNS) hydroalcoholic extract (PNSE) are reported. Chemical degradation of PNSE demonstrated the presence of condensed tannins as the main phenolic components. PNSE showed remarkable antioxidant properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (EC₅₀ = 0.004 mg/mL). PNSE was initially tested as an inhibitor of mushroom tyrosinase, exhibiting a quite low IC₅₀ value (0.055 mg/mL) against the enzyme diphenolase activity, suggesting its use in enzymatic browning inhibition. The anthocyanin stabilization properties were evaluated under accelerated aging conditions of both pure pigments and commercial fruit juices, and PNSE was found to be effective at concentrations (0.05 mg/mL) at which well-known stabilizers such as chlorogenic and ferulic acids proved to fail. PNSE also performed well in the stabilization of spray-dried anthocyanins for use as a food colorant, increasing the half-life of blackberry anthocyanins up to 20%. In order to explore the possibility of using PNSE as a functional additive for active packaging, polylactic acid (PLA) films containing PNSE were prepared by solvent casting, and no substantial alteration of the mechanical properties was found on addition of the extract up to 10% w/w. The films showed remarkable antioxidant properties (DDPH reduction >60% with a 3% w/w loading, at a dose of 1 mg/mL in the DPPH solution) and delayed the onset of browning of apple smoothies (ca. 30% inhibition with a 10% w/w loading). These results highlight the exploitation of PNS as a low-cost polyphenol source for food industry applications.

Coumaroyl Flavonol Glycosides and More in Marketed Green Teas: An Intrinsic Value beyond Much-Lauded Catechins

Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.

Acrocomia aculeata (Jacq.) Lodd. ex Mart. Leaves Increase SIRT1 Levels and Improve Stress Resistance

Oxidative stress is a metabolic disorder linked with several chronic diseases, and this condition can be improved by natural antioxidants. The fruit pulp of the palm Acrocomia aculeata (Jacq.) Lodd. ex Mart. is widely used in the treatment of various illnesses, but as far as we know, there are no reports regarding the properties of its leaves. Thus, we aimed to evaluate the antioxidant activity of A. aculeata leaf extracts obtained with water (EA-Aa), ethanol (EE-Aa), and methanol (EM-Aa) solvents. The extracts were chemically characterized, and their antioxidant activity was assessed through the scavenging of the free radicals DPPH and ABTS. EE-Aa and EM-Aa showed the highest amounts of phenolic compounds and free radical scavenging activity. However, EA-Aa was more efficient to protect human erythrocytes against AAPH-induced hemolysis and lipid peroxidation. Thus, we further show the antioxidant effect of EA-Aa in preventing AAPH-induced protein oxidation, H₂O₂-induced DNA fragmentation, and ROS generation in Cos-7 cells. Increased levels of Sirt1, catalase, and activation of ERK and Nrf2 were observed in Cos-7 treated with EA-Aa. We also verify increased survival in nematodes C. elegans, when induced to the oxidative condition by Juglone. Therefore, our results showed a typical chemical composition of plants for all extracts, but the diversity of compounds presented in EA-Aa is involved in the lower toxicity and antioxidant properties provided to the macromolecules tested, proteins, DNA, and lipids. This protective effect also proven in Cos-7 and in C. elegans was probably due to the activation of the Sirt1/Nrf2 pathway. Altogether, the low toxicity and the antioxidant properties of EA-Aa showed in all the experimental models support its further use in the treatment of oxidative stress-related diseases.

Chitosan-cellulose hydrogel conjugated with L-histidine and zinc oxide nanoparticles for sustained drug delivery: Kinetics and in-vitro biological studies

Functionalised nanohybrid hydrogel using L-Histidine (HIS) conjugated chitosan, phyto-synthesised zinc oxide nanoparticles (ZNPs) and dialdehyde cellulose (DAC) was formulated as a sustained drug delivery carrier for the polyphenol drugs - Naringenin (NRG), Quercetin (QE) and Curcumin (CUR). A maximum loading efficiency of 90.55 %, 92.84 % and 89.89 %, respectively were optimised for NRG, QE and CUR in the hybrid hydrogel. The maximum drug release was favoured for the optimum drug loading and at pH-5. HIS-chitosan conjugation stabilised the hydrogel and enabled a sustained drug delivery. Drug release kinetics predicted a non-Fickian diffusion-based mechanism along with polymer erosion. Prominent antimicrobial activity against Staphylococcus aureus and Trichophyton rubrum strains were predicted to evolve based on the synergic formulation. Significant biocompatibility towards L929 cells revealed their support for normal cell survival. Anticancer studies towards A431 cells exhibited excellent cytotoxicity with a 15 to 30-fold increase using the hybrid carrier, compared to the free polyphenol drugs.

Hempseed Lignanamides Rich-Fraction: Chemical Investigation and Cytotoxicity towards U-87 Glioblastoma Cells

The weak but noteworthy presence of (poly)phenols in hemp seeds has been long overshadowed by the essential polyunsaturated fatty acids and digestible proteins, considered responsible for their high nutritional benefits. Instead, lignanamides and their biosynthetic precursors, phenylamides, seem to display interesting and diverse biological activities only partially clarified in the last decades. Herein, negative mode HR-MS/MS techniques were applied to the chemical investigation of a (poly)phenol-rich fraction, obtained from hemp seeds after extraction/fractionation steps. This extract contained phenylpropanoid amides and their random oxidative coupling derivatives, lignanamides, which were the most abundant compounds and showed a high chemical diversity, deeply unraveled through high resolution tandem mass spectrometry (HR-MS/MS) tools. The effect of different doses of the lignanamides-rich extract (LnHS) on U-87 glioblastoma cell line and non-tumorigenic human fibroblasts was evaluated. Thus, cell proliferation, genomic DNA damage, colony forming and wound repair capabilities were assessed, as well as LnHS outcome on the expression levels of pro-inflammatory cytokines. LnHS significantly inhibited U-87 cancer cell proliferation, but not that of fibroblasts, and was able to reduce U-87 cell migration, inducing further DNA damage. No modification in cytokines' expression level was found. Data acquired suggested that LnHS acted in U-87 cells by inducing the apoptosis machinery and suppressing the autophagic cell death.

Analysis of Phenolic Compounds in Commercial Cannabis sativa L. Inflorescences Using UHPLC-Q-Orbitrap HRMS

Industrial hemp (Cannabis sativa L. Family Cannabaceae) contains a vast number of bioactive relevant compounds, namely polyphenols including flavonoids, phenolic acids, phenol amides, and lignanamides, well known for their therapeutic properties. Nowadays, many polyphenols-containing products made of herbal extracts are marketed, claiming to exert health-promoting effects. In this context, industrial hemp inflorescence may represent an innovative source of bioactive compounds to be used in nutraceutical formulations. The aim of this work was to provide a comprehensive analysis of the polyphenolic fraction contained in polar extracts of four different commercial cultivars (Kompoti, Tiborszallasi, Antal, and Carmagnola Cs) of hemp inflorescences through spectrophotometric (TPC, DPPH tests) and spectrometry measurement (UHPLC-Q-Orbitrap HRMS). Results highlighted a high content of cannflavin A and B in inflorescence analyzed samples, which appear to be cannabis-specific, with a mean value of 61.8 and 84.5 mg/kg, meaning a ten-to-hundred times increase compared to other parts of the plant. Among flavonols, quercetin-3-glucoside reached up to 285.9 mg/kg in the Carmagnola CS cultivar. Catechin and epicatechin were the most representative flavanols, with a mean concentration of 53.3 and 66.2 mg/kg, respectively, for all cultivars. Total polyphenolic content in inflorescence samples was quantified in the range of 10.51 to 52.58 mg GAE/g and free radical-scavenging included in the range from 27.5 to 77.6 mmol trolox/kg. Therefore, C. sativa inflorescence could be considered as a potential novel source of polyphenols intended for nutraceutical formulations.

New SiO2/Caffeic Acid Hybrid Materials: Synthesis, Spectroscopic Characterization, and Bioactivity

The sol–gel route represents a valuable technique to obtain functional materials, in which organic and inorganic members are closely connected. Herein, four hybrid materials, containing caffeic acid entrapped in a silica matrix at 5, 10, 15, and 20 wt.%, were synthesized and characterized through Fourier-Transform Infrared (FT-IR) and Ultraviolet-Visible (UV–Vis) spectroscopy. FT-IR analysis was also performed to evaluate the ability to induce the hydroxyapatite nucleation. Despite some structural changes occurring on the phenol molecular skeleton, hybrid materials showed scavenging properties vs. 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) radical cation (ABTS•⁺), which was dependent on the tested dose and on the caffeic acid wt.%. The SiO₂/caffeic acid materials are proposed as valuable antibacterial agents against Escherichia coli and Enterococcus faecalis.

Cognitive Function and Consumption of Fruit and Vegetable Polyphenols in a Young Population: Is There a Relationship?

Scientific evidence has shown the relationship between consumption of fruits and vegetables and their polyphenols with the prevention or treatment of diseases. The aim of this review was to find out whether the same relationship exists between fruits and vegetables and cognitive function, especially memory, in a young population. The mechanisms by which polyphenols of fruits and vegetables can exert cognitive benefits were also evaluated. These compounds act to improve neuronal plasticity through the protein CREB (Camp Response Element Binding) in the hippocampus, modulating pathways of signaling and transcription factors (ERK/Akt). In the same way, brain-derived neurotrophic factor (BDNF) is implicated in the maintenance, survival, growth, and differentiation of neurons. All these effects are produced by an increase of cerebral blood flow and an increase of the blood’s nitric oxide levels and oxygenation.