Nutrikinetics and urinary excretion of phenolic compounds after a 16-week supplementation with a flavanone-rich ingredient.

Background: Polyphenols are a broad group of compounds with a complex metabolic fate. Flavanones and their metabolites provide cardiovascular protection and assistance in long-term body composition management. Objective: This study evaluates the nutrikinetics and the bioavailability of phenolic compounds after both acute and chronic supplementation with a flavanone-rich product, namely Sinetrol® Xpur, in healthy overweight and obese volunteers. Design: An open-label study including 20 volunteers was conducted for 16 weeks. Participants received Sinetrol® Xpur, either a low dose (900 mg per day) or a high dose (1800 mg per day), in capsules during breakfast and lunch. They were advised to follow an individualized isocaloric diet and avoid a list of polyphenol-rich foods 48 hours before and during the pharmacokinetic measurements. Results: Over 20 phase II and colonic metabolites were measured in the plasma. Two peaks were observed at 1 h and 7h-10 h after the first capsule ingestion. No significant differences in the AUC were observed in circulating metabolites between both doses. In urine excretion, 53 metabolites were monitored, including human phase II and colonic metabolites, at weeks 1 and 16. Cumulative urine excretion was higher after the high dose than after the low dose in both acute and chronic studies. Total urinary metabolites were significantly lower in week 16 compared to week 1. Conclusion: Although the urinary excreted metabolites reduced significantly over 16 weeks, the circulating metabolites did not decrease significantly. This study suggests that chronic intake might not offer the same bioavailability as in the acute study, and this effect does not seem to be dose-dependent. The clinical trial registry number is NCT03823196.

Edible insects and legumes exert an antioxidant effect on human colon mucosal cells stressed with 2,2'-azobis (2-amidinopropane)-dihydrochloride.

Introduction: Edible insects have been recognized as a more sustainable source of nutrients and bio-active compounds than animal-based products, in line with classical vegetable sources such as legumes. In this study, we assessed the antioxidant properties of four edible insects (silkworms, grasshoppers, mealworms and giant worms) and four legume seeds (lentils, chickpeas, Roveja peas and grass peas). Methods: After the aqueous extraction or in vitro simulated digestion process, selected products were assessed for: (i) in vitro antioxidant capacity through Ferric Reducing Antioxidant Power (FRAP) assay; (ii) the ability to reduce free radicals production induced by a pro-oxidant agent in cells of human colonic mucosa. Results: All the aqueous extracts and digesta of edible insects displayed significantly higher in vitro antioxidant activity than legumes. Moreover, edible insects at all tested concentrations were able to exert an antioxidant effect in the cellular model, while legumes were effective mainly at high concentrations. Discussion: Despite human trials are need to confirm and define these results in a physiological situation, here we suggest a role for edible insects in oxidative stress prevention. Since oxidative stress is strongly correlated with several intestinal pathologies, the results obtained could be interesting for the prevention and relief of the negative symptoms, offering new advantages to their already known ecological and nutritional properties.

Association of dietary flavan-3-ol intakes with plasma phenyl-γ-valerolactones: analysis from the TUDA cohort of healthy older adults.

BACKGROUND: Dietary polyphenols, including flavan-3-ols (F3O), are associated with better health outcomes. The relationship of plasma phenyl-γ-valerolactones (PVLs), the products of colonic bacterial metabolism of F3O, with dietary intakes is unclear. OBJECTIVES: To investigate whether plasma PVLs are associated with self-reported intakes of total F3O and procyanidins+(epi)catechins. DESIGN: We measured 9 PVLs by uHPLC-MS-MS in plasma from adults (>60y) in the Trinity-Ulster-Department of Agriculture (TUDA study (2008 to 2012; n=5186) and a follow-up subset (2014 to 2018) with corresponding dietary data (n=557). Dietary (poly)phenols collected by FFQ were analyzed using Phenol-Explorer. RESULTS: Mean (95% confidence interval [CI]) intakes were estimated as 2283 (2213, 2352) mg/d for total (poly)phenols, 674 (648, 701) for total F3O, and 152 (146, 158) for procyanidins+(epi)catechins. Two PVL metabolites were detected in plasma from the majority of participants, 5-(hydroxyphenyl)-γ-VL-sulfate (PVL1) and 5-(4'-hydroxyphenyl)-γ-VL-3'-glucuronide (PVL2). The 7 other PVLs were detectable only in 1-32% of samples. Self-reported intakes (mg/d) of F3O (r = 0.113, P = 0.017) and procyanidin+(epi)catechin (r = 0.122, P = 0.010) showed statistically significant correlations with the sum of PVL1 and PVL 2 (PVL1+2). With increasing intake quartiles (Q1-Q4), mean (95% CI) PVL1+2 increased; from 28.3 (20.8, 35.9) nmol/L in Q1 to 45.2 (37.2, 53.2) nmol/L in Q4; P = 0.025, for dietary F3O, and from 27.4 (19.1, 35.8) nmol/L in Q1 to 46.5 (38.2, 54.9) nmol/L in Q4; P = 0.020, for procyanidins+(epi)catechins. CONCLUSIONS: Of 9 PVL metabolites investigated, 2 were detected in most samples and were weakly associated with intakes of total F3O and procyanidins+(epi)catechins. Future controlled feeding studies are required to validate plasma PVLs as biomarkers of these dietary polyphenols.

Processing and Nutritional Quality of Breakfast Cereals Sold in Italy: Results from the Food Labelling of Italian Products (FLIP) Study.

This study aimed to compare the level of processing (as assessed by the NOVA classification) and the nutritional quality (as assessed by nutrition values, Nutri-Score and NutrInform battery) of breakfast cereals currently on the Italian market. A total of 349 items were found, mostly belonging to the NOVA 4 group (66.5%) and to Nutri-Score C and A (40% and 30%, respectively). The NOVA 4 products showed the highest energy, total fat, saturates, and sugar content per 100 g and had the highest number of items with Nutri-Score C (49%) and D (22%). Conversely, NOVA 1 products had the highest content of fibre and protein, the lowest amounts of sugars and salt, and 82% of them were Nutri-Score A, while few Nutri-Score B and C were found. Differences were attenuated when products were compared for their NutrInform battery, with NOVA 4 items showing only slightly fuller batteries for saturated fats, sugar, and salt than NOVA 1 and NOVA 3 products. Overall, these results suggest that the NOVA classification partially overlaps with systems based on the nutritional quality of foods. The lower nutritional quality of NOVA 4 foods may at least partially explain the association found between the consumption of ultra-processed foods and the risk of chronic diseases.

Interaction Between Diet and Microbiota in the Pathophysiology of Alzheimer's Disease: Focus on Polyphenols and Dietary Fibers.

Animal studies increasingly indicate that the gut microbiota composition and function can be involved in the pathophysiology and progression of Alzheimer's disease (AD) at multiple levels. However, few studies have investigated this putative gut-brain axis in human beings, and none of them considered diet as a determinant of intestinal microbiota composition. Epidemiological studies highlight that a high intake of fruit and vegetables, such as that typical of the Mediterranean diet, can modulate AD progression. Thus, nutritional interventions are being increasingly studied as a possible non-pharmacological strategy to slow down the progression of AD. In particular, polyphenols and fibers represent the nutritional compounds with the higher potential of counterbalancing the pathophysiological mechanisms of dementia due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. These actions are mediated by the gut microbiota, that can transform polyphenols and fibers into biologically active compounds including, among others, phenyl-γ-valerolactones, urolithins, butyrate, and other short-chain fatty acids. In this review, the complex mechanisms linking nutrition, gut microbiota composition, and pathophysiology of cognitive decline in AD are discussed, with a particular focus on the role of polyphenols and fibers. The gaps between pre-clinical and clinical studies are particularly emphasized, as well as the urgent need for studies comprehensively evaluating the link between nutrition, microbiome, and clinical aspects of AD.

Quantifying the human diet in the crosstalk between nutrition and health by multi-targeted metabolomics of food and microbiota-derived metabolites.

BACKGROUND: Metabolomics is a powerful tool for investigating the association between nutrition and health status. Although urine is commonly employed for studying the metabolism and transformation of food components, the use of blood samples could be preferable to gain new insights into the bioavailability of diet-derived compounds and their involvement in health. However, the chemical complexity of blood samples hinders the analysis of this biological fluid considerably, which makes the development of novel and comprehensive analytical methods mandatory. METHODS: In this work, we optimized a multi-targeted metabolomics platform for the quantitative and simultaneous analysis of 450 food-derived metabolites by ultra-high performance liquid chromatography coupled to tandem mass spectrometry. To handle the chemical complexity of blood samples, three complementary extraction methods were assayed and compared in terms of recovery, sensitivity, precision and matrix effects with the aim of maximizing metabolomics coverage: protein precipitation, reversed solid-phase extraction, and hybrid protein precipitation with solid-phase extraction-mediated phospholipid removal. RESULTS: After careful optimization of the extraction conditions, protein precipitation enabled the most efficient and high-throughput extraction of the food metabolome in plasma, although solid-phase extraction-based protocols provided complementary performance for the analysis of specific polyphenol classes. The developed method yielded accurate recovery rates with negligible matrix effects, and good linearity, as well as high sensitivity and precision for most of the analyzed metabolites. CONCLUSIONS: The multi-targeted metabolomics platform optimized in this work enables the simultaneous detection and quantitation of 450 dietary metabolites in short-run times using small volumes of biological sample, which facilitates its application to epidemiological studies.

Specific Dietary (Poly)phenols Are Associated with Sleep Quality in a Cohort of Italian Adults.

BACKGROUND: Diet has been the major focus of attention as a leading risk factor for non-communicable diseases, including mental health disorders. A large body of literature supports the hypothesis that there is a bidirectional association between sleep and diet quality, possibly via the modulation of neuro-inflammation, adult neurogenesis and synaptic and neuronal plasticity. In the present study, the association between dietary total, subclasses of and individual (poly)phenols and sleep quality was explored in a cohort of Italian adults. METHODS: The demographic and dietary characteristics of 1936 adults living in southern Italy were analyzed. Food frequency questionnaires (FFQs) were used to assess dietary intake. Data on the (poly)phenol content in foods were retrieved from the Phenol-Explorer database. The Pittsburg Sleep Quality Index was used to measure sleep quality. Multivariate logistic regression analyses were used to test the associations. RESULTS: A significant inverse association between a higher dietary intake of lignans and inadequate sleep quality was found. Additionally, individuals with the highest quartile of hydroxycinnamic acid intake were less likely to have inadequate sleep quality. When individual compounds were taken into consideration, an association with sleep quality was observed for naringenin and apigenin among flavonoids, and for matairesinol among lignans. A secondary analysis was conducted, stratifying the population into normal weight and overweight/obese individuals. The findings in normal weight individuals showed a stronger association between certain classes of, subclasses of and individual compounds and sleep quality. Notably, nearly all individual compounds belonging to the lignan class were inversely associated with inadequate sleep quality. In the overweight/obese individuals, there were no associations between any dietary (poly)phenol class and sleep quality. CONCLUSIONS: The results of this study suggest that a higher dietary intake of certain (poly)phenols may be associated with better sleep quality among adult individuals.

Diet and Mental Health: Review of the Recent Updates on Molecular Mechanisms.

Over the last decades, there has been a substantial increase in the prevalence of mental health disorders, including an increased prevalence of depression, anxiety, cognitive, and sleep disorders. Diet and its bioactive components have been recognized among the modifiable risk factors, possibly influencing their pathogenesis. This review aimed to summarize molecular mechanisms underlying the putative beneficial effects toward brain health of different dietary factors, such as micro- and macronutrient intake and habits, such as feeding time and circadian rhythm. The role of hormonal homeostasis in the context of glucose metabolism and adiponectin regulation and its impact on systemic and neuro-inflammation has also been considered and deepened. In addition, the effect of individual bioactive molecules exerting antioxidant activities and acting as anti-inflammatory agents, such as omega-3 fatty acids and polyphenols, considered beneficial for the central nervous system via modulation of adult neurogenesis, synaptic and neuronal plasticity, and microglia activation has been summarized. An overview of the regulation of the gut-brain axis and its effect on the modulation of systemic inflammation and oxidative stress has been provided. Finally, the impact of bioactive molecules on inflammation and oxidative stress and its association with brain health has been summarized.

Role of berries in vascular function: a systematic review of human intervention studies.

CONTEXT: Berries are a source of polyphenols with recognized health-promoting activities. Several studies suggest that consumption of berries may improve vascular function. OBJECTIVE: The aim of this systematic review is to provide evidence of short- and long-term benefits of berries on outcomes of vascular function. DATA SOURCES: Human intervention studies were collected from PubMed and Scopus databases. STUDY SELECTION: Studies were eligible if they investigated the effects of acute or chronic berry consumption on one or more markers of vascular function in humans and provided a characterization of the berry polyphenolic content. Only randomized controlled trials were included, and studies were excluded if berries were combined with other foods. DATA EXTRACTION: After selection, 22 randomized controlled trials were included and analyzed, most of which were performed in healthy individuals or patients with cardiovascular risk factors. RESULTS: The overall results seem to suggest a protective role of berries in vascular function, likely dependent on the time of exposure, the type and dose of berry, and the biomarkers analyzed. Flow-mediated dilation and reactive hyperemia index (markers of vascular reactivity) improved following short-term interventions, while pulse wave velocity and augmentation index (markers of arterial stiffness) improved only after medium- to long-term intervention. CONCLUSIONS: Current evidence suggests that berries, at physiological relevant doses, may have a role in the modulation of vascular function and stiffness. High-quality human intervention trials are encouraged in order to strengthen these findings and to better elucidate the mechanisms involved in such modulation.

Differential Catabolism of an Anthocyanin-Rich Elderberry Extract by Three Gut Microbiota Bacterial Species.

Elderberries are good sources of anthocyanins, which are poorly absorbed in the upper gastrointestinal tract but extensively transformed into phenolic metabolites at the colonic level. Because different gut microbiota strains have different metabolism, the catabolism of anthocyanins may lead to interindividual differences in metabolite production. In this work, an anthocyanin-rich elderberry extract was incubated with three single gut microbial strains (Enterobacter cancerogenous, Bifidobacterium dentium, and Dorea longicatena) up to 4 days, to assess differences in their phenolic metabolism. All of the strains degraded the elderberry anthocyanins, but the metabolic pathways followed were different. Although some metabolites were common for all of the strains, a wide disparity was observed in the kind and amount of several phenolic metabolites produced by each species. These in vitro preliminary results may be of help in the interpretation of the bioavailability of anthocyanins and give a clue to understand interindividual variability in metabolite production.

Acute Intake of a Grape and Blueberry Polyphenol-Rich Extract Ameliorates Cognitive Performance in Healthy Young Adults During a Sustained Cognitive Effort.

Despite an increasing level of evidence supporting the individual beneficial effect of polyphenols on cognitive performance, information related to the potential synergistic action of these phytonutrients on cognitive performance during a prolonged cognitive effort is currently lacking. This study investigated the acute and sustained action of a polyphenols-rich extract from grape and blueberry (PEGB), on working memory and attention in healthy students during a prolonged and intensive cognitive effort. In this randomised, cross-over, double blind study, 30 healthy students consumed 600 mg of PEGB or a placebo. Ninety minutes after product intake, cognitive functions were assessed for one hour using a cognitive demand battery including serial subtraction tasks, a rapid visual information processing (RVIP) task and a visual analogical scale. Flow-mediated dilation (FMD) and plasma flavan-3-ols metabolites quantification were also performed. A 2.5-fold increase in serial three subtraction variation net scores was observed following PEGB consumption versus placebo (p < 0.001). A trend towards significance was also observed with RVIP percentage of correct answers (p = 0.058). No treatment effect was observed on FMD. Our findings suggest that consumption of PEGB coupled with a healthy lifestyle may be a safe alternative to acutely improve working memory and attention during a sustained cognitive effort.

5-(Hydroxyphenyl)-γ-Valerolactone-Sulfate, a Key Microbial Metabolite of Flavan-3-ols, Is Able to Reach the Brain: Evidence from Different in Silico, In Vitro and In Vivo Experimental Models.

Phenolic compounds have been recognized as promising compounds for the prevention of chronic diseases, including neurodegenerative ones. However, phenolics like flavan-3-ols (F3O) are poorly absorbed along the gastrointestinal tract and structurally rearranged by gut microbiota, yielding smaller and more polar metabolites like phenyl-γ-valerolactones, phenylvaleric acids and their conjugates. The present work investigated the ability of F3O-derived metabolites to cross the blood-brain barrier (BBB), by linking five experimental models with increasing realism. First, an in silico study examined the physical-chemical characteristics of F3O metabolites to predict those most likely to cross the BBB. Some of these metabolites were then tested at physiological concentrations to cross the luminal and abluminal membranes of brain microvascular endothelial cells, cultured in vitro. Finally, three different in vivo studies in rats injected with pure 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, and rats and pigs fed grapes or a F3O-rich cocoa extract, respectively, confirmed the presence of 5-(hydroxyphenyl)-γ-valerolactone-sulfate (3',4' isomer) in the brain. This work highlighted, with different experimental models, the BBB permeability of one of the main F3O-derived metabolites. It may support the neuroprotective effects of phenolic-rich foods in the frame of the "gut-brain axis".

Fruit and vegetable consumption and health outcomes: an umbrella review of observational studies.

The aim of this study was to provide a comprehensive evaluation of current evidence on fruit and vegetable consumption and health outcomes. A systematic search for quantitative syntheses was performed. Several criteria, including study design, dose-response relationship, heterogeneity and agreement of results over time, and identification of potential confounding factors, were used to assess the level of evidence. The strongest (probable) evidence was found for cardiovascular disease protection; possible evidence for decreased risk of colon cancer, depression and pancreatic diseases was found for fruit intake; and colon and rectal cancer, hip fracture, stroke, depression and pancreatic diseases was found for vegetable intake. Suggestive and rather limited associations with other outcomes have been found. Evidence of potential confounding by sex and geographical localisation has been reported. Despite findings are consistent enough for hypothesising causation (at least for cardiovascular-related outcomes), further studies are needed to clarify the role of potential confounding factors.

Dark chocolate modulates platelet function with a mechanism mediated by flavan-3-ol metabolites.

Cocoa is a rich source bioactive compounds, i.e., flavan-3-ols, and its consumption has been associated with several beneficial effects, such as the positive modulation of the hemostasis targeted by the platelet function. However, these phenolic compounds have a very low bioavailability and extensively undergo phase I and II metabolism, with the appearing into the bloodstream of (epi)catechin conjugates and phenyl-γ-valerolactones and their conjugates, at different times.The aims of this study were to explore the effect of dark chocolate on platelet function and to investigate the relationship between this interplay and flavan-3-ol derived metabolites.Eighteen healthy male volunteers ingested 50 g of 90% cocoa chocolate within 5 minutes. Blood samples were collected immediately before chocolate ingestion (T0) and 4 hours afterwards (T1). Platelet function analyzer (PFA)-100 closure time was assessed using collagen/adenosine-5'-diphosphate (COL/ADP) and collagen/epinephrine (COL/EPI) cartridges. Plasma flavan-3-ol metabolites were identified and quantified by means of liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-ESI-MS/MS).Results evidenced a significant increase of COL/ADP-induced PFA-100 closure time, but not COL/EPI, 4 hours after ingestion of dark chocolate. Total plasma structurally-related (epi)catechin metabolite (SREM) concentration significantly increased at T1, together with 4 out of the 6 detected metabolites. Total phenyl-γ-valerolactone concentrations remained unchanged. Spearman correlations evidenced a strong correlation between COL/ADP closure time and SREMs, mainly led by (epi)catechin-sulfate isomers.These data confirm that the potential beneficial effect of dark chocolate on primary hemostasis may be mediated by flavan-3-ol circulating metabolites.

Bioaccessibility and bioavailability of phenolic compounds in bread: a review.

Cereal-based products, like breads, are a vehicle for bioactive compounds, including polyphenols. The health effects of polyphenols like phenolic acids (PAs) are dependent on their bioaccessibility and bioavailability. The present review summarizes the current understanding of potential strategies to improve phenolic bioaccessibility and bioavailability and the main findings of in vitro and in vivo studies investigating these strategies applied to breads, including the use of raw ingredients with greater phenolic content and different pre-processing technologies, such as fermentation and enzymatic treatment of ingredients. There is considerable variability between in vitro studies, mainly resulting from the use of different methodologies, highlighting the need for standardization. Of the few in vivo bioavailability studies identified, acute, single-dose studies demonstrate that modifications to selected raw materials and bioprocessing of bran could increase the bioavailability, but not necessarily the net content, of bread phenolics. The two medium-term identified dietary interventions also demonstrated greater phenolic content, resulting from the modification of the raw materials used. Overall, the findings suggest that several strategies can be used to develop new bread products with greater phenolic bioaccessibility and bioavailability. However, due to the large variability and the few studies available, further investigations are required to determine better the usefulness of these innovative processes.

Enhancement of flavonoid ability to cross the blood-brain barrier of rats by co-administration with α-tocopherol.

Vitamin E and polyphenols could exhibit a therapeutic role in the treatment of oxidative stress-induced neurodegenerative diseases. Therefore, their ability to cross the blood-brain barrier (BBB) represents an important issue to be explored by different diet combinations. In this study, we have evaluated the ability of α-tocopherol to support epigallocatechin-3-gallate (EGCG), quercetin and rutin to cross the BBB, following oral administration. Eighteen rats were fed a standard diet (C), a diet supplemented with α-tocopherol (A), with a mixture of EGCG, quercetin and rutin (P); or with a mixture of α-tocopherol and the three flavonoids (AP). Flavonoids and their conjugated derivatives were assayed in brain and plasma by HPLC-MS, whereas α-tocopherol was detected by RP-HPLC. The oxidative damage, due to the potential pro-oxidant activity of flavonoids, was evaluated by the presence of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in hippocampal Cornus Ammonis, one of the most vulnerable sites in the brain. Our results indicate that α-tocopherol is able to promote quercetin transport across the BBB. The mixture of rutin and quercetin seems to favour the accumulation of quercetin and/or its conjugated derivatives in the brain. In contrast, α-tocopherol does not affect EGCG transport across the BBB. The densitometric analysis of 8-OHdG immunoreactivity does not reveal any difference of oxidative damage among the experimental groups. Our results suggest that α-tocopherol may promote quercetin transport across the BBB, leading to a significant increase of α-tocopherol and quercetin concentration in the brain.

Camelina sativa defatted seed meal contains both alkyl sulfinyl glucosinolates and quercetin that synergize bioactivity.

Camelina sativa L. Crantz is under development as a novel oilseed crop, yet bioefficacy of camelina phytochemicals is unknown. Defatted camelina seed meal contains two major aliphatic glucosinolates (GSLs), glucoarabin (9-(methylsulfinyl)nonylglucosinolate; GSL 9) and glucocamelinin (10-(methylsulfinyl)decylglucosinolate; GSL 10), with traces of a third, 11(methylsulfinyl)undecylglucosinolate and several flavonoids, mostly quercetin glycosides. In Hepa1c1c7 cells, hydrolyzed GSLs (hGSLs) 9 and 10 upregulated the phase II detoxification enzyme quinone reductase (NQO1), with no effect on cytochrome P450 (CYP) 1A1 activity. Isobologram graphs revealed synergy of NQO1 induction for a combination of hGSL 9 and quercetin. These findings suggest that defatted camelina seed meal should be evaluated for anticancer activity, similar to broccoli and other Brassicaceae family members. Interestingly, synergy of NQO1 induction was also seen for physiologically relevant doses of sulforaphane (SF) and quercetin, two key bioactives present in broccoli. This suggests that SF within broccoli may be more potent than purified SF.

Nutritional and functional potential of Beta vulgaris cicla and rubra.

Swiss chard (Beta vulgaris cicla, BVc) and beetroot (Beta vulgaris rubra, BVr) are vegetables of the Chenopodiaceae family, widely consumed in traditional western cooking. These vegetables represent a highly renewable and cheap source of nutrients. They can be cultivated in soils with scarce organic material and little light and water. BVc and BVr have a long history of use in folk medicine. Modern pharmacology shows that BVc extracts possess antihypertensive and hypoglycaemic activity as well as excellent antioxidant activity. BVc contains apigenin flavonoids, namely vitexin, vitexin-2-O-rhamnoside and vitexin-2-O-xyloside, which show antiproliferative activity on cancer cell lines. BVr contains secondary metabolites, called betalains, which are used as natural dyes in food industry and show anticancer activity. In this light, BVc and BVr can be considered functional foods. Moreover, the promising results of their phytochemicals in health protection suggest the opportunity to take advantage of the large availability of this crop for purification of chemopreventive molecules to be used in functional foods and nutraceutical products.

An enzyme-linked immunosorbent assay for the measurement of plasma flavonoids in mice fed apigenin-C-glycoside.

BACKGROUND: In the Chenopodiaceae family, the apigenin flavonoids vitexin-2-O-xyloside (VOX) and vitexin-2-O-rhamnoside (VOR) are important chemopreventive components. To investigate their bioavailability in in vivo animal studies an enzyme-linked immunosorbent assay (ELISA) method has been developed. RESULTS: The ELISA was based on polyclonal antibodies elicited in mice by injecting, as an immunogen, 4',6″-O-biapigenin (hinokiflavone, HF) conjugated to bovine serum albumin (BSA-HF). A second immunogen was synthesised by coupling an equimolar mixture of VOX and VOR to BSA (BSA-F1). The BSA-HF elicited a significant antibody response, due to 17 HF hapten groups, coupled to each BSA molecule, whereas BSA-F1 provided a very low antigenicity in respect to control animals. Antiserum raised against BSA-HF showed an antibody titre of 1:1600. Antibodies were found to be specific for the flavonols. Our results show that VOX and its metabolic products reached the concentration of 3.42 ± 0.72 µg mL⁻¹ in plasma of VOX fed animals, at the net of the control value. CONCLUSIONS: By using the ELISA, the concentration of apigenin flavonoids and their metabolites can be detected in VOX- or VOR-supplemented animals. The assay represents a useful tool for rapid screening to compare bioavailability of apigenin flavonoids in respect to control animals.

Vitexin-2-O-xyloside, raphasatin and (-)-epigallocatechin-3-gallate synergistically affect cell growth and apoptosis of colon cancer cells.

Cytotoxic effects of the combination of the food components vitexin-2-O-xyloside (X), raphasatin (4-methylsulphanyl-3-butenyl isothiocyanates; G) and (-)-epigallocatechin-3-gallate (E) were investigated in colon (LoVo and CaCo-2) and breast (MDA-MB-231 and MCF-7) cancer cells. Breast cancer cells were more resistant than colon cells to X, G and E inhibition. On the contrary, marked synergistic effects among X, G and E on cell growth were found in both colon cancer cells. Further analysis revealed a G0/G1 arrest of the phase cell progression and apoptosis, linked to modulation of Bax, Bcl2, caspase-9 and poly(ADP-ribose) polymerase as well as Reactive Oxygen Species (ROS) generation in both colon cancer cells, whereas apoptosis and ROS were not significantly detected in normal human lymphocytes. We conclude that the X, G and E mixture might act by mitochondrial pathway activation of apoptosis, possibly elicited by ROS and the mixture may be effective in the chemoprevention of colon cancer.