New Insights in (Poly)phenolic Compounds: From Dietary Sources to Health Evidence

Differences Due to Sex and Sweetener on the Bioavailability of (Poly)phenols in Urine Samples: A Machine Learning Approach

Metabolic diseases have been related to the overdrinking of high-sugar content beverages. As a result, the demand for alternative formulations based on plant-based ingredients with health-promoting properties has increased during the last few years. Nonetheless, the design and production of effective formulations requires understanding the bioavailability of these compounds. For this purpose, a two-month longitudinal trial with 140 volunteers was conducted to measure the beneficial effects of a maqui-citrus beverage, rich in (poly)phenols. From data obtained by quantifying metabolites present in urine samples, biostatistical and machine learning (data imputation, feature selection, and clustering) methods were applied to assess whether a volunteer's sex and the sweetener added to the beverage (sucrose, sucralose, or stevia) affected the bioavailability of (poly)phenol metabolites. Several metabolites have been described as being differentially influenced: 3,4-dihydroxyphenylacetic acid and naringenin with its derivatives were positively influenced by stevia and men, while eriodictyol sulfate and homoeridictyol glucunoride concentrations were enhanced with stevia and women. By examining groups of volunteers created by clustering analysis, patterns in metabolites' bioavailability distribution as a function of sex and/or sweeteners (or even due to an uncontrolled factor) were also discovered. These results underline the potential of stevia as a (poly)phenol bioavailability enhancer. Furthermore, they also evidence sex affects the bioavailability of (poly)phenols, pointing at a sex-dependent metabolic pathway regulation.

Contribution of the diverse experimental models to unravelling the biological scope of dietary (poly)phenols

The health benefits associated with (poly)phenols need to be supported by robust and insightful information on their biological effects. The use of in vitro, ex vivo, and in vivo models is crucial to demonstrate functionalities in specific targets. In this regard, bioaccessibility, bioavailability, and tissue/organ distribution need to be fully understood and established. In addition, the structure-function relationships, concerning both descriptive and mechanistic information, between specific compounds and therapeutic objectives, need to be supported by results obtained from in vivo studies. Nevertheless, these studies are not always possible or have some limitations, particularly concerning the mechanistic information explaining the health benefits provided that should be covered with complementary experimental models. Based on these premises, this review aims to overview the contribution of the separate experimental approaches to gain insights into the bioaccessibility, bioavailability, and bioactivity of (poly)phenols. To achieve this objective, recent evidence available on the linkage of healthy/functional foods with the incidence of non-communicable pathologies is presented. The different experimental approaches provide complementary information that allows advances to be applied to the knowledge gained on the functional properties and mechanistic facts responsible for the health attributions of polyphenols. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A New Food Ingredient Rich in Bioaccessible (Poly)Phenols (and Glucosinolates) Obtained from Stabilized Broccoli Stalks

Broccoli (Brassica oleracea var. italica) stalks account for up to 35% of the broccoli harvest remains with the concomitant generation of unused waste that needs recovery to contribute to the sustainability of the system. However, due to its phytochemical composition, rich in bioactive (poly)phenols and glucosinolates, as well as other nutrients, the development of valorization alternatives as a source of functional ingredients must be considered. In this situation, the present work aims to develop/obtain a new ingredient rich in bioactive compounds from broccoli, stabilizing them and reducing their degradation to further guarantee a high bioaccessibility, which has also been studied. The phytochemical profile of lyophilized and thermally treated (low-temperature and descending gradient temperature treatments), together with the digested materials (simulated static in vitro digestion) were analysed by HPLC-PDA-ESI-MSn and UHPLC-3Q-MS/MS. Broccoli stalks and co-products were featured by containing phenolic compounds (mainly hydroxycinnamic acid derivatives and glycosylated flavonols) and glucosinolates. The highest content of organosulfur compounds corresponding to the cores of the broccoli stalks treated by applying a drying descendant temperature gradient (aliphatic 18.05 g/kg dw and indolic 1.61 g/kg dw, on average, while the breakdown products were more abundant in the bark ongoing low temperature drying 11.29 g/kg dw, on average). On the other hand, for phenolics, feruloylquinic, and sinapoylquinic acid derivatives of complete broccoli stalk and bark, were more abundant when applying low-temperature drying (14.48 and 28.22 g/kg dw, on average, respectively), while higher concentrations were found in the core treated with decreasing temperature gradients (9.99 and 26.26 g/kg dw, on average, respectively). When analysing the bioaccessibility of these compounds, it was found that low-temperature stabilization of the core samples provided the material with the highest content of bioactives including antioxidant phenolics (13.6 and 33.9 g/kg dw of feruloylquinic and sinapoylquinic acids, on average, respectively) and sulforaphane (4.1 g/kg dw, on average). These processing options enabled us to obtain a new product or ingredient rich in bioactive and bioaccessible compounds based on broccoli stalks with the potential for antioxidant and anti-inflammatory capacities of interest.

The use of alternative sweeteners (sucralose and stevia) in healthy soft-drink beverages, enhances the bioavailability of polyphenols relative to the classical caloric sucrose

The comparison of non-caloric sweeteners (stevia and sucralose) and sucrose, on the plasma concentration and cumulative effects of phenolic compounds, was achieved. A long-term intervention, consisting of the daily intake of 330 mL of healthy citrus-maqui soft drinks, for 60 days, by 138 healthy overweight adults, was followed. A total of 24 bioavailable metabolites derived from caffeic acid, 3,4-di-hydroxyphenylacetic acid, eriodictyol, homoeriodictyol, hippuric acid, naringenin, 2,4,6-tri-hydroxybenzaldehyde, and vanillic acid were detected in peripheral blood plasma. A similar augment of bioactive compounds in plasma concentrations were found for the three beverages, in the range 12.3% (day 0)- 85.3% (day 60), depending on the analyte considered. Due to this, the present study highlights sucralose and stevia as valuable alternatives to sucrose, providing and non-significantly different plasma concentration and cumulative effect in the plasma, thus contributing to prevent a diversity of metabolic disorders and health constraints.

Effects and underlying mechanisms of food polyphenols in treating gouty arthritis: A review on nutritional intake and joint health

Gouty arthritis, one of the most severe and common forms of arthritis, is characterized by monosodium urate crystal deposition in joints and surrounding tissues. Epidemiological evidence indicates that gouty arthritis incidence is sharply rising globally. Polyphenols are found in many foods and are secondary metabolites in plant foods. The anti-inflammatory and antioxidant effects of food polyphenols have been extensively studied in many inflammatory chronic diseases. Research has suggested that many food polyphenols have excellent anti-gouty arthritis effects. The mechanisms mainly include (a) inhibiting xanthine oxidase activity; (b) reducing the levels of inflammatory cytokines and chemokines; (c) inhibiting the activation of signaling pathways and the NLRP3 inflammasome; and (d) reducing oxidative stress. This paper reviews the research progress and pathogenesis of gouty arthritis and introduces the mechanisms of food polyphenols in treating gouty arthritis, which aims to explore the potential of functional foods in the treatment of gouty arthritis. PRACTICAL APPLICATIONS: The incidence rate of gouty arthritis has increased sharply worldwide, which has seriously affected people's quality of life. According to the current research progress, food polyphenols alleviate gouty arthritis through anti-inflammatory and antioxidant effects. This paper reviews the research progress and molecular pathogenesis of gouty arthritis and introduces the mechanisms of food-derived polyphenols in the treatment of gouty arthritis, which is helpful to the prevention and treatment of gouty arthritis.

In Vitro Evidence on Bioaccessibility of Flavonols and Cinnamoyl Derivatives of Cruciferous Sprouts

Cruciferous sprouts are rising in popularity as a hallmark of healthy diets, partially because of their phytochemical composition, characterized by the presence of flavonols and cinnamates. However, to shed light on their biological activity, the ability to assimilate (poly)phenols from sprouts (bioaccessible fraction) during gastrointestinal digestion needs to be studied. In this frame, the present work studies the effect of the physicochemical and enzymatic characteristics of gastrointestinal digestion on flavonols and cinnamoyl derivatives, by a simulated static in vitro model, on different cruciferous (red radish, red cabbage, broccoli, and white mustard) sprouts. The results indicate that, although the initial concentrations of phenolic acids in red radish (64.25 mg/g fresh weight (fw)) are lower than in the other sprouts studied, their bioaccessibility after digestion is higher (90.40 mg/g fw), followed by red cabbage (72.52 mg/g fw), white mustard (58.72 mg/g fw), and broccoli (35.59 mg/g fw). These results indicate that the bioaccessibility of (poly)phenols is not exclusively associated with the initial concentration in the raw material, but that the physico-chemical properties of the food matrix, the presence of other additional molecules, and the specific characteristics of digestion are relevant factors in their assimilation.

Evidence on the Bioaccessibility of Glucosinolates and Breakdown Products of Cruciferous Sprouts by Simulated In Vitro Gastrointestinal Digestion

Cruciferous vegetables are gaining importance as nutritious and sustainable foods, rich in phytochemical compounds such as glucosinolates (GSLs). However, the breakdown products of these sulfur-based compounds, mainly represented by isothiocyanates (ITC) and indoles, can contribute to human health. In the human digestive system, the formation of these compounds continues to varying extents in the different stages of digestion, due to the contact of GSLs with different gastric fluids and enzymes under the physicochemical conditions of the gastrointestinal tract. Therefore, the aim of the present work was to uncover the effect of gastrointestinal digestion on the release of glucosinolates and their transformation into their bioactive counterparts by applying a simulated in vitro static model on a range of brassica (red radish, red cabbage, broccoli, and mustard) sprouts. In this sense, significantly higher bioaccessibility of ITC and indoles from GSLs of red cabbage sprouts was observed in comparison with broccoli, red radish, and mustard sprouts, due to the aliphatic GSLs proportion present in the different sprouts. This indicates that the bioaccessibility of GSLs from Brasicaceae sprouts is not exclusively associated with the initial content of these compounds in the plant material (almost negligible), but also with the release of GSLs and the ongoing breakdown reactions during the gastric and intestinal phases of digestion, respectively. Additionally, aliphatic GSLs provided higher bioaccessibility of their corresponding ITC in comparison to indolic and aromatic GSLs.

A review on the fruit components affecting uric acid level and their underlying mechanisms

Uric acid (UA) is produced in the liver and excreted through the kidneys and intestines. If UA is overproduced or its excretion reduces, the concentration of UA increases, leading to hyperuricemia and gout. The high concentration of UA is also related to cardiovascular disease, hypertension, obesity, and other diseases. Fruits are healthy foods. However, fruits contain fructose and small amounts of purine, and the product of their metabolism is UA. Therefore, theoretically, eating fruits will increase the concentration of serum UA. Fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In addition to the UA synthesized by fructose and purine metabolism, the mechanisms by which other components affect the concentration of serum UA can be summarized as follows: (a) inhibiting xanthine oxidase; (b) reducing reabsorption of UA; and (c) improving the excretion of UA. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations, and explained their mechanisms for the first time, which references for patients with hyperuricemia to take fruits. PRACTICAL APPLICATIONS: With the rising prevalence, hyperuricemia and gout have become public health problems that endanger our daily life. The key to the treatment of hyperuricemia is to control the level of serum UA within the normal range. Fruits are healthy foods. However, fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations. We also explained their mechanisms, which references for patients with hyperuricemia to take fruits.

Anything New under the Sun? An Update on Modulation of Bioactive Compounds by Different Wavelengths in Agricultural Plants

Plants continuously rely on light as an energy source and as the driver of many processes in their lifetimes. The ability to perceive different light radiations involves several photoreceptors, which in turn activate complex signalling cascades that ultimately lead to a rearrangement in plant metabolism as an adaptation strategy towards specific light conditions. This review, after a brief summary of the structure and mode of action of the different photoreceptors, introduces the main classes of secondary metabolites and specifically focuses on the influence played by the different wavelengths on the content of these compounds in agricultural plants, because of their recognised roles as nutraceuticals.

Antioxidants in Plants: A Valorization Potential Emphasizing the Need for the Conservation of Plant Biodiversity in Cuba

Plants are phytochemical hubs containing antioxidants, essential for normal plant functioning and adaptation to environmental cues and delivering beneficial properties for human health. Therefore, knowledge on the antioxidant potential of different plant species and their nutraceutical and pharmaceutical properties is of utmost importance. Exploring this scientific research field provides fundamental clues on (1) plant stress responses and their adaptive evolution to harsh environmental conditions and (2) (new) natural antioxidants with a functional versatility to prevent and treat human pathologies. These natural antioxidants can be valorized via plant-derived foods and products. Cuba contains an enormously rich plant biodiversity harboring a great antioxidant potential. Besides opening new avenues for the implementation of sustainable agroecological practices in crop production, it will also contribute to new strategies to preserve plant biodiversity and simultaneously improve nature management policies in Cuba. This review provides an overview on the beneficial properties of antioxidants for plant protection and human health and is directed to the valorization of these plant antioxidants, emphasizing the need for biodiversity conservation.

Fruit Quality Characterization of New Sweet Cherry Cultivars as a Good Source of Bioactive Phenolic Compounds with Antioxidant and Neuroprotective Potential

Sweet cherries (Prunus avium L.) are highly appreciated fruits for their taste, color, nutritional value, and beneficial health effects. In this work, seven new cultivars of sweet cherry were investigated for their main quality traits and nutraceutical value. The phytochemical profile of three classes of phenolic compounds and the antioxidant activity of the new cultivars were investigated through high-performance liquid chromatography with diode array detection (HPLC-DAD) and spectrophotometric assays, respectively, and compared with those of commonly commercialized cultivars. Cyanidine-3-O-rutinoside was the main anthocyanin in all genotypes, and its levels in some new cultivars were about three-fold higher than in commercial ones. The ORAC-assayed antioxidant capacity was positively correlated with the total anthocyanin index. The nutraceutical value of the new cultivars was investigated in terms of antioxidant/neuroprotective capacity in neuron-like SH-SY5Y cells. Results demonstrated that the new cultivars were more effective in counteracting oxidative stress and were also able to upregulate brain-derived neurotrophic factor (BDNF), a pro-survival neurotrophin, suggesting their potential pleiotropic role in counteracting neurodegenerations.