Brassica genus includes known horticultural vegetables with major economical importance worldwide... more Brassica genus includes known horticultural vegetables with major economical importance worldwide, and involves vegetables of economical importance being part of the diet and source of oils for industry in many countries. Brassicales own a broad array of health-promoting compounds, emphasized as healthy rich sources of vitamin C. The adequate management of pre-and postharvest factors including crop varieties, growth conditions, harvesting, handling, storage, and final consumer operations would lead to increase or preserve of the vitamin C content or reduced losses by interfering in the catalysis mechanisms that remains largely unknown, and should be reviewed. Likewise, the importance of the food matrix on the absorption and metabolism of vitamin C is closely related to the range of the health benefits attributed to its intake. However, less beneficial effects were derived when purified compounds were administered in comparison to the ingestion of horticultural products such as Brassicas, which entail a closely relation between this food matrix and the bioavailability of its content in vitamin C. This fact should be here also discussed.
Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in ... more Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in their production by the gut microbiota. This work represents a first in vitro step toward the development of new strategies focused on the oral supplementation of urolithins with the aim of overcoming their selective production and making their putative health benefits available for the whole population. In order to study their gastrointestinal stability, urolithin A, urolithin B, and urolithin B-glucuronide, as well as ellagic acid, were subjected to a simulated gastrointestinal digestion model consisting of oral, gastric, and pancreatic steps followed by a 24-h fecal fermentation. The effect of the entero-hepatic recirculation on urolithin B-glucuronide, a phase II metabolite, was also investigated. Urolithin B was the molecule able to resist to a greater extent the conditions of the gastrointestinal tract, while urolithin A and ellagic acid were drastically unstable during the colonic...
Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers... more Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4'-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1-1.5h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate thei...
The Eph-ephrin system comprises emerging proteins involved in many pathophysiological processes. ... more The Eph-ephrin system comprises emerging proteins involved in many pathophysiological processes. The pharmacological activity of the main metabolites derived from the intake of some classes of (poly)phenolic compounds, such as caffeoylquinic acids, flavan-3-ols, and ellagitannins, on the Eph-ephrin interaction was evaluated at physiological concentrations. Functional studies to elucidate their role in prostate cancer were also performed. Among the 21 phenolics screened by an ELISA-binding assay, just urolithin C, urolithin D, and ellagic acid succeeded to inhibit the EphA2-ephrin-A1 binding. Urolithin D, the most active, was a competitive and reversible antagonist of EphA receptors able to discriminate between EphA and EphB receptors, showing intra-classes selectivity. Molecular modeling and structure-activity relationships shed light on the binding mode and selective activity of urolithin D. This catabolite blocked EphA2 phosphorylation mediated by ephrin-A1, while lacking cytotoxicity and anti-proliferative effects, and was inactive on the EphA2 kinase assay. The mechanisms behind the cancer preventive properties of foods rich in flavan-3-ols and caffeoylquinic acids are not associated with metabolic pathways directly linked to the Eph-ephrin system. However, the ellagitannin-derived colonic metabolite urolithin D was able to exert remarkable and selective EphA-ephrin-A inhibition, which might impact on prostate cancer prevention.
Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in ... more Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in their production by the gut microbiota. This work represents a first in vitro step toward the development of new strategies focused on the oral supplementation of urolithins with the aim of overcoming their selective production and making their putative health benefits available for the whole population. In order to study their gastrointestinal stability, urolithin A, urolithin B, and urolithin B-glucuronide, as well as ellagic acid, were subjected to a simulated gastrointestinal digestion model consisting of oral, gastric, and pancreatic steps followed by a 24-h fecal fermentation. The effect of the entero-hepatic recirculation on urolithin B-glucuronide, a phase II metabolite, was also investigated. Urolithin B was the molecule able to resist to a greater extent the conditions of the gastrointestinal tract, while urolithin A and ellagic acid were drastically unstable during the colonic step. Conjugation with glucuronic acid, ideally occurring in the liver, conferred to urolithin B an increased stability, which may be interesting in the framework of entero-hepatic recirculation. This set of experiments lets hypothesize that orally supplemented urolithins may come into contact with the colonic epithelium and become accessible for uptake or exert local anti-inflammatory activity, overcoming the limitations of enterotypes unable to convert ellagitannins into these putatively beneficial metabolites.
This work aimed to assess the effect of combining two pomegranate (Punica granatum L.) cultivars ... more This work aimed to assess the effect of combining two pomegranate (Punica granatum L.) cultivars at different rates on the ellagitannin content, antioxidant capacity, and total phenolic content of varietal pomegranate juices. Widely distinct juices made from Mollar de Elche and Wonderful cultivars were used for the elaboration of blended juices. They were stored for 70 days at both room and refrigeration temperatures. This study revealed a significant cultivar effect on the stability of main pomegranate ellagitannins (punicalagins, punicalins, punicalagin-like compound, and ellagic acid derivatives) and on the antioxidant capacity measured by the ABTS+ and DPPH* in vitro assays. Blended juices enhanced and/or retained the initial ellagitannin content and antioxidant capacity of pure juices during storage. Thus, blending varietal juices could be suggested as a promising alternative to the development of fresh juices with a high, stable phytochemical load.
Introduction. In recent years, the interest in dietary antioxidants and foods naturally rich in b... more Introduction. In recent years, the interest in dietary antioxidants and foods naturally rich in bioactive compounds has prompted the research in the field of polyphenols and health. The aim of the present work was to design a new beverage, with a mixture of lemon juice and maqui berry concentrates, as natural source of colouring anthocyanins, in order to provide consumers with healthy and appetizing functional drinks. Methods and materials. Maqui berry powdered fruits were added lemon juice or citric acid controls at two concentrations (2.5% w/v and 5% w/v). Freshly-prepared lemon juice was also assayed as control. The flavonoids (flavones, flavanones, and anthocyanins) and the vitamin C of the mixtures and the controls were analysed and compounds identified and quantified by HPLC-DAD. The quality colour parameters were recorded and processed in a computer-based colorimetric system. The in vitro antioxidant capacity was also determined by the ABTS+ method. Total phenolics content (T...
International journal of food sciences and nutrition, Jan 30, 2015
Pomegranate (Punica granatum L.) has been used for centuries for the treatment of inflammatory di... more Pomegranate (Punica granatum L.) has been used for centuries for the treatment of inflammatory diseases. However, there is a lack of comprehensive information focused on the properties of a certain pomegranate (poly)phenolic profile to cure pain and gastric injury induced by anti-inflammatory drugs. This study investigated the systemic effects of different doses of a HPLC-characterized pomegranate extract on the formalin-induced nociceptive behavior in mice. The effect of the extract against gastric injury caused by non-steroidal anti-inflammatory drugs and ethanol was also assessed. Pomegranate reduced nociception in both phases of the formalin test, suggesting central and peripheral activities to inhibit nociception. Indomethacin-induced gastric injury was not produced in the presence of pomegranate, which also protected against ethanol-induced gastric lesions. The present results reinforce the benefits of pomegranate (poly)phenolics in the treatment of pain as well as their anti-...
Journal of agricultural and food chemistry, Jan 25, 2014
Topoisomerases are targeted by several drugs in cancer chemotherapy acting as key enzymes in cell... more Topoisomerases are targeted by several drugs in cancer chemotherapy acting as key enzymes in cell viability. Some flavonoids and their glycosides may exert health protective effects through the poisoning of topoisomerases. However, previous studies did not consider the substantial modifications taking place after ingestion neglecting that only metabolites can interact with the internal compartments of the human body. Since the high number of possible metabolites hinders their systematic analysis, an in silico approach can be a valuable tool to prioritize compounds by identifying candidates for further characterization. Specifically focusing on luteolin and quercetin, among the most ubiquitous flavonoids in the human diet, this work reports a computational procedure to model the effect of hepatic phase II conjugative metabolism on poisoning of human Topoisomerase I. As a general effect, glucuronidation and sulphation might enhance and quench poisoning activity, respectively. Among al...
The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in ... more The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Non-thermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidize...
Diabetic cardiomyopathy (DCM) develops independently of common cardiovascular comorbidities and i... more Diabetic cardiomyopathy (DCM) develops independently of common cardiovascular comorbidities and is initiated by the metabolic derangements accompanying diabetes mellitus, including hyperglycaemia, which may cause a mild inflammatory state able to negatively affect myocardial biochemistry, structure, and function. This work shows how different urolithins, ellagitannin-derived metabolites, were able to modulate the pro-inflammatory mediators and growth factors secreted by rat cardiac myocytes and fibroblasts exposed to high glucose concentrations. At 1 µM concentration, coherent with dietary exposure to ellagitannin-rich foods, urolithins B and B-glucuronide succeeded in preventing inflammatory responses in cardiomyocytes, while in fibroblasts urolithin D was the most effective in controlling the overexpression of fractalkine, among the tested inflammatory mediators. Urolithins underwent extensive biotransformations in both cell types, including (de)glucuronidation, methylation, and sulphation. This suggests that the inflammatory bulk produced by hyperglycaemia could be attenuated by the regular intake of ellagitannin-rich foodstuffs such as pomegranates, raspberries, blackberries, strawberries, and walnuts.
ABSTRACT There is continuously accruing evidence to suggest the health benefits of consuming frui... more ABSTRACT There is continuously accruing evidence to suggest the health benefits of consuming fruits and vegetables. Food supplements may represent an effective and acceptable method to deliver a way of providing bioactive compounds to consumers. The aim of this work was to characterize the (poly)phenolic composition of three plant-based food supplements designed to integrate and increase the daily intake of dietary phenolics. The supplements are blends of berries, fruits, or vegetables made from a total of 36 different edible food plants. The best conditions for phenolic extraction were assessed and the total phenolic content of each supplement was estimated (it ranged from 50 to 176 mg/g powder). The analysis of the three supplements by uHPLC–MSn allowed to tentatively identify in all 119 (poly)phenolic compounds belonging to different classes, namely ellagitannins, gallotannins, dihydrochalcones, flavan-3-ols including proanthocyanidins, flavanones, flavones, flavonols, anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, phenylethanoids, and lignans. The contribution of these food supplements to the daily intake of (poly)phenolic compounds and, in turn, the potential contribution of such intake to health were discussed.
ABSTRACT Tannins, both hydrolyzable and condensed, are frequently found in edible plants and plan... more ABSTRACT Tannins, both hydrolyzable and condensed, are frequently found in edible plants and plant-derived foods, although a comprehensive knowledge of their dietary intake is not available due to various constraints. They might be responsible for some of the advantages ascribed to dietary regimens rich in plant foods. Notwithstanding the evidence from epidemiological and cohort studies, an unambiguous and exhaustive pattern has not yet emerged regarding the mechanisms underlying their food-related health properties, and no conclusive answers have been given on their actual bioavailability. It is now increasingly evident that the sole direct action of substances available in planta is not sufficient to fully explain the benefits of polyphenol-rich dietary habits. To fully elucidate this conundrum, a better comprehension of the interplay between gut microbial metabolism and dietary polyphenols is needed. This chapter provides a detailed overview of the current knowledge on distribution and human biotransformation of the most widespread classes of high-molecular-weight polyphenols: procyanidins, ellagitannins and gallotannins. According to data collected, these substances reach the human colon almost intact, where they undergo a wide range of rearrangements and biotransformations and actively modulate the composition of the colonic microflora. A deeper knowledge of their colonic metabolites, of their catabolic patterns and of the bacterial strains involved is needed to properly assess the overall contribution to human health, to single out bioactive substances and to identify adequate strategies to enhance their bioavailability.
Brassica genus includes known horticultural vegetables with major economical importance worldwide... more Brassica genus includes known horticultural vegetables with major economical importance worldwide, and involves vegetables of economical importance being part of the diet and source of oils for industry in many countries. Brassicales own a broad array of health-promoting compounds, emphasized as healthy rich sources of vitamin C. The adequate management of pre-and postharvest factors including crop varieties, growth conditions, harvesting, handling, storage, and final consumer operations would lead to increase or preserve of the vitamin C content or reduced losses by interfering in the catalysis mechanisms that remains largely unknown, and should be reviewed. Likewise, the importance of the food matrix on the absorption and metabolism of vitamin C is closely related to the range of the health benefits attributed to its intake. However, less beneficial effects were derived when purified compounds were administered in comparison to the ingestion of horticultural products such as Brassicas, which entail a closely relation between this food matrix and the bioavailability of its content in vitamin C. This fact should be here also discussed.
Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in ... more Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in their production by the gut microbiota. This work represents a first in vitro step toward the development of new strategies focused on the oral supplementation of urolithins with the aim of overcoming their selective production and making their putative health benefits available for the whole population. In order to study their gastrointestinal stability, urolithin A, urolithin B, and urolithin B-glucuronide, as well as ellagic acid, were subjected to a simulated gastrointestinal digestion model consisting of oral, gastric, and pancreatic steps followed by a 24-h fecal fermentation. The effect of the entero-hepatic recirculation on urolithin B-glucuronide, a phase II metabolite, was also investigated. Urolithin B was the molecule able to resist to a greater extent the conditions of the gastrointestinal tract, while urolithin A and ellagic acid were drastically unstable during the colonic...
Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers... more Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4'-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1-1.5h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate thei...
The Eph-ephrin system comprises emerging proteins involved in many pathophysiological processes. ... more The Eph-ephrin system comprises emerging proteins involved in many pathophysiological processes. The pharmacological activity of the main metabolites derived from the intake of some classes of (poly)phenolic compounds, such as caffeoylquinic acids, flavan-3-ols, and ellagitannins, on the Eph-ephrin interaction was evaluated at physiological concentrations. Functional studies to elucidate their role in prostate cancer were also performed. Among the 21 phenolics screened by an ELISA-binding assay, just urolithin C, urolithin D, and ellagic acid succeeded to inhibit the EphA2-ephrin-A1 binding. Urolithin D, the most active, was a competitive and reversible antagonist of EphA receptors able to discriminate between EphA and EphB receptors, showing intra-classes selectivity. Molecular modeling and structure-activity relationships shed light on the binding mode and selective activity of urolithin D. This catabolite blocked EphA2 phosphorylation mediated by ephrin-A1, while lacking cytotoxicity and anti-proliferative effects, and was inactive on the EphA2 kinase assay. The mechanisms behind the cancer preventive properties of foods rich in flavan-3-ols and caffeoylquinic acids are not associated with metabolic pathways directly linked to the Eph-ephrin system. However, the ellagitannin-derived colonic metabolite urolithin D was able to exert remarkable and selective EphA-ephrin-A inhibition, which might impact on prostate cancer prevention.
Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in ... more Urolithins are bioactive ellagitannin-derived metabolites showing a wide phenotypic variation in their production by the gut microbiota. This work represents a first in vitro step toward the development of new strategies focused on the oral supplementation of urolithins with the aim of overcoming their selective production and making their putative health benefits available for the whole population. In order to study their gastrointestinal stability, urolithin A, urolithin B, and urolithin B-glucuronide, as well as ellagic acid, were subjected to a simulated gastrointestinal digestion model consisting of oral, gastric, and pancreatic steps followed by a 24-h fecal fermentation. The effect of the entero-hepatic recirculation on urolithin B-glucuronide, a phase II metabolite, was also investigated. Urolithin B was the molecule able to resist to a greater extent the conditions of the gastrointestinal tract, while urolithin A and ellagic acid were drastically unstable during the colonic step. Conjugation with glucuronic acid, ideally occurring in the liver, conferred to urolithin B an increased stability, which may be interesting in the framework of entero-hepatic recirculation. This set of experiments lets hypothesize that orally supplemented urolithins may come into contact with the colonic epithelium and become accessible for uptake or exert local anti-inflammatory activity, overcoming the limitations of enterotypes unable to convert ellagitannins into these putatively beneficial metabolites.
This work aimed to assess the effect of combining two pomegranate (Punica granatum L.) cultivars ... more This work aimed to assess the effect of combining two pomegranate (Punica granatum L.) cultivars at different rates on the ellagitannin content, antioxidant capacity, and total phenolic content of varietal pomegranate juices. Widely distinct juices made from Mollar de Elche and Wonderful cultivars were used for the elaboration of blended juices. They were stored for 70 days at both room and refrigeration temperatures. This study revealed a significant cultivar effect on the stability of main pomegranate ellagitannins (punicalagins, punicalins, punicalagin-like compound, and ellagic acid derivatives) and on the antioxidant capacity measured by the ABTS+ and DPPH* in vitro assays. Blended juices enhanced and/or retained the initial ellagitannin content and antioxidant capacity of pure juices during storage. Thus, blending varietal juices could be suggested as a promising alternative to the development of fresh juices with a high, stable phytochemical load.
Introduction. In recent years, the interest in dietary antioxidants and foods naturally rich in b... more Introduction. In recent years, the interest in dietary antioxidants and foods naturally rich in bioactive compounds has prompted the research in the field of polyphenols and health. The aim of the present work was to design a new beverage, with a mixture of lemon juice and maqui berry concentrates, as natural source of colouring anthocyanins, in order to provide consumers with healthy and appetizing functional drinks. Methods and materials. Maqui berry powdered fruits were added lemon juice or citric acid controls at two concentrations (2.5% w/v and 5% w/v). Freshly-prepared lemon juice was also assayed as control. The flavonoids (flavones, flavanones, and anthocyanins) and the vitamin C of the mixtures and the controls were analysed and compounds identified and quantified by HPLC-DAD. The quality colour parameters were recorded and processed in a computer-based colorimetric system. The in vitro antioxidant capacity was also determined by the ABTS+ method. Total phenolics content (T...
International journal of food sciences and nutrition, Jan 30, 2015
Pomegranate (Punica granatum L.) has been used for centuries for the treatment of inflammatory di... more Pomegranate (Punica granatum L.) has been used for centuries for the treatment of inflammatory diseases. However, there is a lack of comprehensive information focused on the properties of a certain pomegranate (poly)phenolic profile to cure pain and gastric injury induced by anti-inflammatory drugs. This study investigated the systemic effects of different doses of a HPLC-characterized pomegranate extract on the formalin-induced nociceptive behavior in mice. The effect of the extract against gastric injury caused by non-steroidal anti-inflammatory drugs and ethanol was also assessed. Pomegranate reduced nociception in both phases of the formalin test, suggesting central and peripheral activities to inhibit nociception. Indomethacin-induced gastric injury was not produced in the presence of pomegranate, which also protected against ethanol-induced gastric lesions. The present results reinforce the benefits of pomegranate (poly)phenolics in the treatment of pain as well as their anti-...
Journal of agricultural and food chemistry, Jan 25, 2014
Topoisomerases are targeted by several drugs in cancer chemotherapy acting as key enzymes in cell... more Topoisomerases are targeted by several drugs in cancer chemotherapy acting as key enzymes in cell viability. Some flavonoids and their glycosides may exert health protective effects through the poisoning of topoisomerases. However, previous studies did not consider the substantial modifications taking place after ingestion neglecting that only metabolites can interact with the internal compartments of the human body. Since the high number of possible metabolites hinders their systematic analysis, an in silico approach can be a valuable tool to prioritize compounds by identifying candidates for further characterization. Specifically focusing on luteolin and quercetin, among the most ubiquitous flavonoids in the human diet, this work reports a computational procedure to model the effect of hepatic phase II conjugative metabolism on poisoning of human Topoisomerase I. As a general effect, glucuronidation and sulphation might enhance and quench poisoning activity, respectively. Among al...
The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in ... more The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Non-thermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidize...
Diabetic cardiomyopathy (DCM) develops independently of common cardiovascular comorbidities and i... more Diabetic cardiomyopathy (DCM) develops independently of common cardiovascular comorbidities and is initiated by the metabolic derangements accompanying diabetes mellitus, including hyperglycaemia, which may cause a mild inflammatory state able to negatively affect myocardial biochemistry, structure, and function. This work shows how different urolithins, ellagitannin-derived metabolites, were able to modulate the pro-inflammatory mediators and growth factors secreted by rat cardiac myocytes and fibroblasts exposed to high glucose concentrations. At 1 µM concentration, coherent with dietary exposure to ellagitannin-rich foods, urolithins B and B-glucuronide succeeded in preventing inflammatory responses in cardiomyocytes, while in fibroblasts urolithin D was the most effective in controlling the overexpression of fractalkine, among the tested inflammatory mediators. Urolithins underwent extensive biotransformations in both cell types, including (de)glucuronidation, methylation, and sulphation. This suggests that the inflammatory bulk produced by hyperglycaemia could be attenuated by the regular intake of ellagitannin-rich foodstuffs such as pomegranates, raspberries, blackberries, strawberries, and walnuts.
ABSTRACT There is continuously accruing evidence to suggest the health benefits of consuming frui... more ABSTRACT There is continuously accruing evidence to suggest the health benefits of consuming fruits and vegetables. Food supplements may represent an effective and acceptable method to deliver a way of providing bioactive compounds to consumers. The aim of this work was to characterize the (poly)phenolic composition of three plant-based food supplements designed to integrate and increase the daily intake of dietary phenolics. The supplements are blends of berries, fruits, or vegetables made from a total of 36 different edible food plants. The best conditions for phenolic extraction were assessed and the total phenolic content of each supplement was estimated (it ranged from 50 to 176 mg/g powder). The analysis of the three supplements by uHPLC–MSn allowed to tentatively identify in all 119 (poly)phenolic compounds belonging to different classes, namely ellagitannins, gallotannins, dihydrochalcones, flavan-3-ols including proanthocyanidins, flavanones, flavones, flavonols, anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, phenylethanoids, and lignans. The contribution of these food supplements to the daily intake of (poly)phenolic compounds and, in turn, the potential contribution of such intake to health were discussed.
ABSTRACT Tannins, both hydrolyzable and condensed, are frequently found in edible plants and plan... more ABSTRACT Tannins, both hydrolyzable and condensed, are frequently found in edible plants and plant-derived foods, although a comprehensive knowledge of their dietary intake is not available due to various constraints. They might be responsible for some of the advantages ascribed to dietary regimens rich in plant foods. Notwithstanding the evidence from epidemiological and cohort studies, an unambiguous and exhaustive pattern has not yet emerged regarding the mechanisms underlying their food-related health properties, and no conclusive answers have been given on their actual bioavailability. It is now increasingly evident that the sole direct action of substances available in planta is not sufficient to fully explain the benefits of polyphenol-rich dietary habits. To fully elucidate this conundrum, a better comprehension of the interplay between gut microbial metabolism and dietary polyphenols is needed. This chapter provides a detailed overview of the current knowledge on distribution and human biotransformation of the most widespread classes of high-molecular-weight polyphenols: procyanidins, ellagitannins and gallotannins. According to data collected, these substances reach the human colon almost intact, where they undergo a wide range of rearrangements and biotransformations and actively modulate the composition of the colonic microflora. A deeper knowledge of their colonic metabolites, of their catabolic patterns and of the bacterial strains involved is needed to properly assess the overall contribution to human health, to single out bioactive substances and to identify adequate strategies to enhance their bioavailability.
Uploads
Papers by Pedro Mena