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Chemical structures of the different classes of polyphenols. Polyphenols are classified on the basis of the number of phenol rings that they contain and of the structural elements that bind these rings to one another. They are broadly dived in four classes; Phenolic acids, flavonoids, stilbenes and lignans. Phenolic acids are further divided into hydroxyl benzoic and hydroxyl cinnamic acids. Phenolic acids account for about a third of the polyphenolic compounds in our diet and are found in all plant material, but are particularly abundant in acidic-tasting fruits. Caffeic acid, gallic acid, ferulic acid are some common phenolic acids. Flavonoids are most abundant polyphenols in human diet and share a common basic structure consist of two aromatic rings, which are bound together by three carbon atoms that form an oxygenated heterocycle. Biogenetically, one ring usually arises from a molecule of resorcinol, and other ring is derived from the shikimate pathway. Stilbenes contain two phenyl moieties connected by a twocarbon methylene bridge. Most stilbenes in plants act as antifungal phytoalexins, compounds that are synthesized only in response to infection or injury. The most extensively studied stilbene is resveratrol. Lignans are diphenolic compounds that contain a 2,3-dibenzylbutane structure that is formed by the dimerization of two cinnamic acid residues.
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Polyphenols are secondary metabolites of plants and are generally involved in defense against ultraviolet radiation or aggression by pathogens. In the last decade, there has been much interest in the potential health benefits of dietary plant polyphenols as antioxidant. Epidemiological studies and associated meta-analyses strongly suggest that long...
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... Polyphenols may be classified into different groups as a function of the number of phenol rings that they contain and on the basis of structural elements that bind these rings to one another. The main classes include phenolic acids, flavonoids, stilbenes and lignans. 2 Figure 2 illustrates the different groups of polyphenols and their chemical structures. flavanones, flavanols, anthocyanins and isoflavones (Fig. 3). ...Context 2
... are diphenolic compounds that contain a 2,3-dibenzylbu- tane structure that is formed by the dimerization of two cinnamic acid residues (Fig. 2). Several lign- ans, such as secoisolariciresinol, are considered to be phytoestrogens. The richest dietary source is linseed, which contains secoisolariciresinol (up to 3.7 g/kg dry weight) and low quantities of matairesinol. ...Context 3
... comprise the most studied group of polyphenols. This group has a common basic structure consisting of two aro- matic rings bound together by three carbon atoms that form an oxygenated heterocycle (Fig. 2). More than 4,000 varieties of flavonoids have been identified, many of which are respon- sible for the attractive colours of the flowers, fruits and leaves. 8 Based on the variation in the type of heterocycle involved, fla- vonoids may be divided into six subclasses: flavonols, flavones, it is very difficult to identify all the ...Citations
... Unlike conventional thermal processing, which degrades heatsensitive bioactives, the synergistic mechanical and cavitational effects of HPP-USP enhance cell wall disruption while minimizing oxidative losses [4]. These retained phenolics serve dual roles: (1) as functional enhancers, contributing to the sugar's antioxidant and anti-inflammatory potential [19], and (2) as physicochemical stabilizers during freezedrying. Phenolic compounds can inhibit recrystallization and reduce hygroscopicity in the lyophilized matrix [20], directly improving shelf life and reconstitution properties, critical factors for industrial applications [21]. ...
Dates and their derivatives play a significant role in human nutrition, offering health benefits through valuable bioactive compounds such as polyphenols and flavonoids. Conventionally, the processing of date palm juice and the production of lyophilized date sugar involve heat treatments, which may degrade these sensitive compounds. This study aims to optimize non-thermal extraction methods—specifically High-Pressure Processing (HPP), Ultrasonic Processing (USP), and their combination, to enhance the yield and preservation of bioactive compounds in Deglet-Nour date palm juice. A full factorial experimental design was employed, varying processing time, pressure, ultrasound application, and freeze–thaw pretreatment across 18 extraction trials. The combined HPP-USP treatment for 30 min resulted in the highest total phenolic content (308.16 ± 0.27 mg GAE/100 g FW), total flavonoid content (328.54 ± 0.12 mg QE/100 g FW), and antioxidant activity (34.2 ± 1.05 mM Trolox/100 g FW). Additionally, this treatment achieved peak sugar concentrations, with total sugars at 699.71 ± 0.08 g/L and reducing sugars at 262 ± 0.05 g/L. These findings demonstrate that the synergistic application of HPP and USP significantly enhances the extraction efficiency and preservation of bioactive and nutritional compounds, offering a promising non-thermal alternative for the sustainable production of functional palm sugar.
... Los compuestos fenólicos o polifenólicos se clasifican de acuerdo con el tipo y número de anillos fenólicos que contienen y la forma en que estos se unen. En general son 4 tipos: ácidos fenólicos, flavonoides, estilbenos y lignanos (Pandey & Rizvi, 2009). Los compuestos polifenólicos pueden desempeñar su actividad antioxidante a través de diferentes mecanismos de acción: capturando radicales libres, disminuyendo el oxígeno singulete, quelando metales de transición, inhibiendo enzimas, etc. (Mucha et al., 2021). ...
Los compuestos fenólicos se encuentran en las plantas y poseen una alta capacidad antioxidante. Se han reportado diversas metodologías para la Cuantificación de Fenoles Totales, sin embargo, es común que no se evalúe el efecto que tienen las pequeñas modificaciones de las diversas variables involucrados en el procedimiento. Por este motivo, en este trabajo se propone optimizar las diversas variables del análisis, realizar la validación y evaluar su aplicación en extractos de plantas. Se seleccionó el agua como medio de disolución y se redujo el volumen de reacción hasta 200 µL. Se optimizó el volumen del reactivo de Folin-Ciocalteau (33.5 µL), el volumen de carbonato de sodio al 20% (86.5 µL) y el tiempo de reacción (46.5 min). Bajo estas condiciones se realizaron curvas de calibración y se estableció la linealidad, la precisión y la exactitud, el Limite de Detección y Límite de Cuantificación. Se evaluó la robustez del método y el efecto de la matriz, determinando que el método es robusto, pero existe interferencia de la matriz. Se concluyó que la cuantificación se debe realizar por una curva de adición estándar.
... Many plant species have been shown to have around 8000 polyphenolic chemicals. (207) Polyphenols compounds have a common chemical structure, which are benzene derivatives with one or more hydroxyl groups attached to the ring. Because of their structure, these compounds can actively operate as reducing agents, pro-oxidant metal chelators, scavengers to stabilize free radicals, and quenchers to generate singlet oxygen. ...
Abdominal obesity, dyslipidemia, hypertension, and hyperglycemia are metabolic risk factors that are grouped together to define metabolic syndrome (MetS). It is now widely recognized that MetS is linked to a higher risk of type 2 diabetes (T2DM) and cardiovascular disease (CVD). Overall, the pathophysiology of MetS initiated by the imbalance of nutrition intake and physical activity. It involves a complex interplay of insulin resistance (IR), inflammation, dysregulated adipocyte function, and genetic susceptibility, all of which contribute to the metabolic dysfunction. Lifestyle modifications play a crucial role in managing and preventing MetS. Key strategies include adopting a balanced diet like Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH), or caloric restriction (CR), engaging in regular physical activity, and maintaining a healthy weight. Nutraceuticals, including polyphenols and CR-mimetic agents, improve insulin sensitivity, reduce inflammation, lower blood pressure and cholesterol levels, reducing oxidative stress, and promoting autophagy. In addition to lifestyle changes, drug therapy may be necessary for some individuals to manage specific risk factors, such as diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARB), calcium channel blockers, and beta blockers for hypertension; biguanides, sulfonylureas, dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide 1(GLP-1) receptor agonists, sodium-glucose co-transporter 2 (SGLT2) inhibitors, and thiazolidinediones for hyperglycemia; and statins for dyslipidemia. Early diagnosis, including waist circumference and blood pressure measurement, serum cholesterol and glucose testing, and intervention, is essential to effectively manage MetS and prevent the progression of associated diseases. In conclusion, understanding the risk factors and associated risks of MetS, along with the implementation of lifestyle modifications such as dietary and nutraceutical interventions including polyphenols and CR-mimetic agents, is vital for reducing the burden of this syndrome. Early diagnosis and proactive management are key to improving long-term health outcomes.KEYWORDS: metabolic syndrome, abdominal obesity, insulin resistance, diet, nutraceuticals
... Polyphenol compounds have been shown to provide health benefits in preventing various diseases, including cancer, metabolic syndrome, diabetes, non-alcoholic liver disease, and periodontal disease. Traditionally, the health benefits of polyphenolic compounds have been attributed to their antioxidant activity (25). Knowledge of chemical plant components is essential for quality control analysis of plants, extracts, or any formulation containing chemical plant components. ...
The term “hepatoprotective”
describes a substance’s capacity to shield the liver
from harm. This may entail lowering
inflammation, encouraging liver cell regeneration,
or limiting damage from toxins. The current study's
findings indicated that prunetin had phenolic
content, proteins, amino acids, sterols, glycosides,
saponins, flavonoids, alkaloids, and carbs. Of all
the flavonoids, prunetin's hepatoprotective action is
caused by glycosides and phenolic compounds. To
determine the appropriate dosage of the non-toxic
prunetin, additional acute toxicity research was
conducted. According to an acute toxic research,
the safe doses are 20 mg/kg and 40 mg/kg.
... Overproduction of free radicals is associated with the pathogenesis of various xenobiotics toxicity (Hagerman et al., 1998;Jaeschke et al., 2003;Pandey and Rizvi, 2009). Therefore, scavenging DPPH, HO°, and NO° radicals appears as one of the best barometers to assess the antioxidant potential of plant extracts. ...
Objective: This study aimed at investigating the protective effect of extracts from Apium graveolens against gentamicin-induced hepato-renal toxicity. Materials and Methods: The aqueous and hydro-ethanolic extracts of A. graveolens designated respectively as WAG and HAG were tested for their in vitro antioxidant activities. Then, their cytoprotective effects were assessed against gentamicin-induced cytotoxicity in primary mouse hepatocytes. Finally, mice were administered with gentamicin (20 mg/kg) and co-treated with HAG for 14 days, and histopathology, biochemical and molecular parameters related to gentamicin-induced toxicity were evaluated. Results: HAG exhibited outstanding chemical antioxidant activities and preserved hepatocytes from gentamicin-induced cytotoxicity. HAG relieved liver and kidney histopathological and biochemical changes, and enhanced the mRNA level of Nrf2 and its target gene HO-1 in gentamicin-intoxicated mice. Conclusion: HAG attenuates hepato-renal injuries induced by 14-days administration of gentamicin in mice through the activation of Nrf2-antioxidant signaling pathways.. Extracts of Apium graveolens (Celery) attenuate hepato-renal injury induced by chronic administration of gentamicin in mice through activation of Nrf2-antioxidant signaling pathways.
... There are initial indications that the enhanced blood antioxidant potential leads to reduced oxidative damage of macromolecules such as DNA and lipids [11]. Several studies highlighted an increase in the antioxidant capacity of plasma after the ingestion of bioactive compounds such as polyphenols including flavonols, flavonones, flavones and phenolic acids present in cocoa beans [12,13]. Chemically, the flavonoids are very effective radical scavengers, and may therefore be active as antioxidant in the digestive tract or in other tissues after uptake. ...
Given the health benefits of antioxidants and the importance to satisfy sensory preferences of the consumers, this study sought to balance cocoa processing methods that enhance sensory properties while preserving bioactive compounds of cocoa beans. The main objective was to elaborate a cocoa liquor with both high antioxidant activity potentials of raw beans and chocolate sensory attributes of treated beans. To achieve this goal, cocoa beans were harvested and divided into two batches. The first batch was fermented and roasted, while the second batch did not undergo any treatment, and both were dried. Fermented and unfermented cocoa beans were blended in different proportions and ground to obtain eleven samples of cocoa liquor named CL1 (100% treated beans/0% raw beans) to CL11 (0% treated beans/100% raw beans) with a step of 10% to select the best formulation. The external and internal quality of beans was evaluated by performing graining, cut test and the measure of pH. The proximate composition, as well as the zinc, iron, copper and selenium content of the cocoa liquor were determined as these minerals are cofactors of antioxidant reactions. Total polyphenols, total flavonoids, proanthocyanins and in vitro antioxidant activity of the cocoa liquor was assessed. A sensory assessment identified the cocoa liquor with the best balance of antioxidant potential and desirable organoleptic properties. The results showed that with an average mass of 1.43 g per bean and pH ≥ 5, both fermented and unfermented cocoa bean were appropriate for chocolate industry. The physicochemical and phytochemical analyses of the liquor showed that liquor CL11 exhibited the highest macronutrients, minerals and bioactive compound content, while sample CL1 recorded the lowest values. Antioxidant activity increased with the addition of unfermented beans in the blend, with the highest values of anti-radical activity and inhibition percentage recorded for sample CL11. Sensory assessment allowed selecting liquor CL3 as the best compromise between antioxidant activity and good sensory profile, notably chocolate flavor and aromas (floral, woody and toasted aromas).
... The phenolic content and related biological activities of grape (V. vinifera and Vitis labrusca) by-products, including seeds and skins, have been thoroughly investigated (Pandey and Rizvi, 2009). However, while having a high polyphenol content, grape shoot wastes-a substantial agricultural by-product-have gotten relatively little attention. ...
Fruits and vegetables are rich in polyphenols, which are secondary metabolites that are essential for both human health and plant defense. This study investigates whether grape shoot debris from two different grape varieties Vitis vinifera and Vitis labrusca-can provide polyphenols. It also looks at how well they combat bacteria, oxidation, and certain enzymes. Grape shoots from Boumerdes and Baghlia were gathered, and 60% ethanol was used to extract them. Thirteen phenolic compounds were discovered by LC-MS/MS, with flavanols being the most prevalent. The primary substance present in all extracts was Catechin. The Fregola Nera variety has the largest quantity at (1449.45 mg/kg DW), followed by the Cardinal variety at (753.53 mg/kg DW). As assessed by phenanthroline tests using silver nanoparticles, the antioxidant activity demonstrated a concentration-dependent impact. The highest antioxidant potential was demonstrated by the Fregola Nera and Cardinal types, which had A0.5 values of 45.12 µg/mL and 49.87 µg/mL, respectively. Strong anti-tyrosinase action was demonstrated by the extracts. The inhibition rate of the Fregola Nera extract was 46.44%, comparable to that found in standard kojic acid (49.46%). With an IC50 value of 25.88 µg/mL, the Cardinal variant demonstrated potent anti-urease activity, blocking 80% at a dosage of 200 µg/mL. This is comparable to the reference inhibitor thiourea, which has an IC50 of 11.57 µg/mL and 98.90% inhibition. Salicylic acid, o-coumaric acid, and gallic acid were the most attracted to urease, according to molecular docking studies. Their binding strengths were-28.88 kJ/mol,-26.51 kJ/mol, and-24.69 kJ/mol, respectively. When the extracts' antibacterial activity was evaluated against Candida albicans and Escherichia coli, it showed significant inhibition. The largest inhibition zone against E. Coli (15 mm) and Candida albicans (20 mm) was seen in the Fregola Nera extract, whereas the Cardinal extract demonstrated inhibition against E. Coli of 16 mm and Candida albicans of 15 mm. All extracts had a minimum inhibitory concentration (MIC) of 6 mg/mL. These findings demonstrate that grape shoot waste can be a valuable source of polyphenols, which have potent antibacterial, antioxidant, and enzyme-blocking properties. This encourages its application in environmentally friendly waste management and health-related products.
... Due to the properties of polyphenols-primarily antioxidative-there is growing interest in using them as dietary ingredients that could improve health or prevent the development of many diseases (chemoprevention). The presence of polyphenols, including flavonoids, in the diet is considered to have beneficial effects on the cardiovascular system, nervous system, immune response, gut microflora, and even the course of bacterial and viral infections, and has been extensively characterized in numerous papers [1][2][3][4][5]. ...
Resveratrol is a natural polyphenol found in grapes, berries, and red wine, commonly studied for its biological activity. In vitro research often uses high concentrations of resveratrol applied for short incubation times. However, resveratrol reaches relatively low concentrations in vivo when it is used as a dietary supplement. Therefore, the aim of this study was to investigate the cellular response of cardiomyocytes to low, physiologically relevant concentrations of resveratrol and, in particular, to compare these responses depending on the duration of exposure. Cardiomyocytes were treated with resveratrol for either 1 day, 1 week, or 1 month. Functional assays assessing metabolic activity, cell cycle distribution, and apoptosis intensity were performed, along with analysis of selected pathways at protein levels. The results showed that the cellular response differed markedly depending on the duration of resveratrol treatment. Observed changes indicated alterations in energy metabolism and effects consistent with anti-aging activity.
... Polyphenols may affect glycemia through different mechanisms, including inhibition of glucose absorption in the gut or its uptake by peripheral tissues. Polyphenols also play a role in reducing the adverse effects of aging on the nervous system and brain (Pandey and Rizvi, 2009). Although several studies have reported on phenolic compounds in vegetables, none have investigated this association in Qatar. ...
The long-term consumption of diets rich in plant polyphenols has a high potential to reduce the risk of chronic diseases such as cancer, cardiovascular disease, and diabetes. This study focuses on the phenolic and antioxidant properties of eight green leafy vegetables, red spinach, green spinach, water spinach, chives, rocca, Swiss chard, jute mallow, and purslane, commonly cultivated in Qatar. Antioxidant capacity (AC) was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The total phenolic content (TPC) of the samples was quantified using the Folin-Ciocalteu assay. Among all the vegetables, results indicated significant differences among all examined values at level of 5% Jute Mallow exhibited the highest phenolic content at 205.39±11.50 mg GA/100g, followed by Green Spinach at 189.58±10.56 mg GA/100g and Red Spinach at 185.15±2.93 mg GA/100g. Swiss chard exhibited the highest antioxidant activity of 89.26%. This study provides valuable data on these vegetables to positively affect the health and well-being of the population. Intensifying further future investigation to embrace a wider phytochemical profile (e.g., flavonoids, carotenoids, vitamin C), varied antioxidant assays (e.g., FRAP, ABTS), and bioavailability tests would expand the understanding of the studied leafy vegetables health benefits.
... The main phenolics are flavonoids and free PA, along with their glycosides and fractions bound to polysaccharides in the cell wall (Gebru et al., 2021;Ravisankar et al., 2018). Phenolic compounds when consumed as part of a balanced diet, provide various health benefits, such as protection against cardiovascular diseases, cancer, diabetes, and age-related degenerative processes (Acosta-Estrada et al., 2014;Pandey & Rizvi, 2009). Identifying alternative sources of phenolic compounds and efficient methods for their recovery is essential for scientific and industrial advancement (Sorita et al., 2023). ...
Teff is a cereal rich in bioactive compounds. These phytochemicals can be recovered through different techniques. In this context, pressurized liquid extraction (PLE) stands out for its advantages of using green solvents, providing high extraction yields and automation. In this study, the physicochemical composition of brown Teff grains was evaluated and phenolic extracts were obtained using PLE and Soxhlet (SE). The antioxidant activity was determined by in vitro assays. A full factorial design was employed to investigate the influence of temperature and solvent on mass yield. Total phenolic content (TPC) was determined by Folin–Ciocalteu method, and antioxidant activity was assessed by DPPH, ABTS and ORAC assays. The extract composition was analyzed by HPLC–UV and FTIR-ATR. Optimal conditions for PLE were 60 °C and 69.86 v/v% ethanol, resulting in a mass yield of 3.09 tw%. This value was close to the mass yield (3.39 tw%) obtained by SE using similar ethanol concentration at the boiling point. The selectivity for compounds with antioxidant activity was increased in PLE. These findings highlight PLE as an efficient method for extracting phenolics from Teff. Ferulic and p-coumaric acid were identified as the main phenolic acids (PA), and FTIR spectral data confirmed the presence of these compounds in the free and soluble fraction. The ORAC method showed a strong positive correlation with TPC, which was attributed to its high sensitivity to the PA present in the extracts.
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