Sweetener influences plasma concentration of flavonoids in humans after an acute intake of a new (poly)phenol-rich beverage.

BACKGROUND AND AIM: The overconsumption of sucrose is closely related to sugar-sweetened beverages and one of the main factors associated with the increase of metabolic diseases, such as type 2 diabetes, obesity, and insulin resistance. So, the addition of alternative sweeteners to new fruit-based drinks could contribute to minimizing the incidence or severity of these pathologies. Nevertheless, current knowledge on the influence of these additives on the bioactive compounds present in these beverages is still scarce.new-onset hypertension, but few data were published in Asian. We aimed to investigate the association of lipid profiles with new-onset hypertension in a Chinese community-based non-hypertensive cohort without lipid-lowering treatment (n = 1802). METHODS AND RESULTS: Hence, to contribute to the understanding of this issue, the plasma concentration of phenolic compounds (anthocyanins and flavanones), after the ingestion of a new maqui-citrus-based beverage, supplemented with sucrose (natural high caloric), stevia (natural non-caloric), or sucralose (artificial non-caloric), was evaluated as evidence of their intestinal absorption and metabolism previous to renal excretion. The beverages were ingested by volunteers (n = 20) and the resulting phenolic metabolites in plasma were analyzed by UHPLC-ESI-MS/MS. A total of 13 metabolites were detected: caffeic acid sulfate, caffeic acid glucuronide, 3,4-dihydroxyfenylacetic, 3,4-dihydroxyfenylacetic sulfate. 3,4-dihydroxyfenylacetic acid di-sulfate, 3,4-dihydroxyfenylacetic di-glucuronide, 3,4-dihydroxyfenylacetic glucuronide-sulfate, trans-ferulic acid glucuronide, naringenin glucuronide, vanillic acid, vanillic acid sulfate, vanillic acid glucuronide-sulfate, and vanillic acid di-glucuronide, being recorded their maximum concentration after 30-60 min. CONCLUSION: In general, sucralose provided the greatest absorption value for most of these metabolites, followed by stevia. Due to this, the present study proposes sucralose and stevia (non-caloric sweeteners) as valuable alternatives to sucrose (high caloric sweetener), to avoid the augmented risk of several metabolic disorders.

Nanoencapsulation in low-molecular-weight chitosan improves in vivo antioxidant potential of black carrot anthocyanin.

BACKGROUND: Anthocyanins are flavonoids that are potential antioxidant, anti-inflammatory, anti-obesity, and anti-carcinogenic nutraceutical ingredients. However, low chemical stability and low bioavailability limit the use of anthocyanins in food. Nanoencapsulation using biopolymers is a recent successful strategy for stabilization of anthocyanins. This study reports the development, characterization, and antioxidant activity of black carrot anthocyanin-loaded chitosan nanoparticles (ACNPs). RESULTS: The ionic gelation technique yielded the ACNPs. The mean hydrodynamic diameter d and polydispersity index PDI of chitosan nanoparticles and ACNPs were found to be d = 455 nm and PDI = 0.542 respectively for chitosan nanoparticles and d = 274 nm and PDI = 0.376 respectively for ACNPs. The size distribution was bimodal. The surface topography revealed that the ACNPs are spherical and display a coacervate structure. Fourier transform infrared analysis revealed physicochemical interactions of anthocyanins with chitosan. The loading process could achieve an encapsulation efficiency of 70%. The flow behavior index η of encapsulated ACNPs samples revealed Newtonian and shear thickening characteristics. There was a marginal reduction in the in vitro antioxidant potential of anthocyanins after nanoencapsulation, as evidenced from 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Interestingly, the in vivo antioxidant potential of anthocyanins improved following nanoencapsulation, as observed in the serum antioxidant assays. CONCLUSION: The optimized nanoencapsulation process resulted in spherical nanoparticles with appreciable encapsulation efficiency. The nanoencapsulation process improved the in vivo antioxidant activity of anthocyanins, indicating enhanced stability and bioavailability. The promising antioxidant activity of the ACNPs suggests a potential for utilization as a nutraceutical supplement. © 2021 Society of Chemical Industry.

Accumulation of plasma levels of anthocyanins following multiple saskatoon berry supplements.

1. Anthocyanins are a subgroup of flavonoids responsible for the blue, purple and red color of many fruits, flowers and leaves. Consumption of foods rich in anthocyanins is associated with a reduced risk of cardiovascular disease and cancer. Most food intervention studies employ once or twice per day dose schedules. 2. The current study demonstrated that plasma concentrations of cyanidin-3-galactoside and cyanidin-3-xyloside, the two major components of saskatoon berries, were significantly increased following three consecutive saskatoon berry supplements 4 hours apart. This accumulation is due to the residual concentrations of anthocyanins at the time of second and third supplements. 3. Accumulation was especially pronounced for peonidin-3-glucoside and peonidin-3-galactoside, the methylated metabolites of cyanidin-3-glucoside and cyanidin-3-galactoside, respectively. Little or no accumulation was observed for cyanidin-3-arabinoside and cyanidin-3-glucoside, two other components of saskatoon berries, possibly due to their short half-lives. 4. Thus, taking anthocyanin supplements with every meal would provide higher plasma concentrations for some anthocyanins and their metabolites than the once or twice-a-day dose regimens.

Assessment of in vitro Effects of Anthocyanins on Platelet Function.

BACKGROUND: Increased platelet activity plays a significant role in the development of arterial thrombosis and cardiovascular disease (CVD). Natural antioxidants including anthocyanin (AC) have gained considerable interest due to their hypothesized antithrombotic potential. PRIMARY STUDY OBJECTIVE: Our study aimed to examine the in vitro effect of AC compounds on platelet activation and aggregation. METHODS: Fasting blood samples were collected from healthy volunteers (n = 13). A full blood examination was done to exclude any abnormal specimen. Flow cytometer assessed platelet activity by recording platelet surface markers expression of P-selectin (CD62P) and PAC-1. Platelet aggregation studies were performed by stimulating platelets using three different agonists adenosine diphosphate (ADP), collagen and arachidonic acid (AA). SETTING: The study was done in the school of Medical Sciences, Griffith University. PARTICIPANTS: Thirteen healthy adult participants were involved for blood collection. INTERVENTION: AC was prepared using hemicellulose capsules sourced from Bilberries and Black Currants. RESULTS: Anthocyanin (50 mg/L) significantly inhibited AA-induced platelet aggregation. Expression of P-selectin was significantly suppressed by 50 mg/L AC as measured by flow cytometer. CONCLUSIONS: AC attenuates platelet function by suppressing P-selectin expression and influencing Thromboxane A2 pathway (AA stimulation). These results provide further evidence for the effect of AC and the possible mechanism by which AC reduces platelet aggregation and activation. This study supports future human intervention trials to show that AC may act as a complement to other antiplatelet agents in reducing the risk of thrombosis.

Development and Validation of Methods for the Determination of Anthocyanins in Physiological Fluids via UHPLC-MSn.

Recent in vitro and in vivo studies on anthocyanins confirmed numerous health-promoting effects in humans. Daily anthocyanin intake can be estimated via food databases, but the amount absorbed by the organism still remains uncertain because anthocyanin bioavailability is yet to be elucidated in its entirety. For this purpose, suitable and validated methods of sample preparation and analysis are required. Therefore, a sample preparation method for anthocyanin metabolite analysis in plasma was successfully established and validated. The validation yielded acceptable results for the anthocyanins in terms of recovery (54-108%) and precision (coefficient of variation (CV) < 15%). The UHPLC-MS method used in the consecutive reaction monitoring (CRM) mode was sufficiently sensitive, resulting in limits of detection <2.3 ng/mL and limits of quantification < 8.1 ng/mL with associated repeatability of the MS system with CVs of <5.1%. In addition, a method for the sum parameter determination of anthocyanidins in urine comprising solely the evaporation of acidified samples was developed, validated, and successfully applied to real samples. The results showed that this method is applicable for the methylated anthocyanidins, but not for the hydroxylated anthocyanidins, due to the chosen CRM modes required for optimum selectivity.

Overexpression of ThMYC4E Enhances Anthocyanin Biosynthesis in Common Wheat.

The basic helix-loop helix (bHLH) transcription factor has been inferred to play an important role in blue and purple grain traits in common wheat, but to date, its overexpression has not been reported. In this study, the bHLH transcription factor ThMYC4E, the candidate gene controlling the blue grain trait from Th. Ponticum, was transferred to the common wheat JW1. The positive transgenic lines displayed higher levels of purple anthocyanin pigments in their grains, leaves and glumes. Stripping the glumes (light treatment) caused white grains to become purple in transgenic lines. RNA-Seq and qRT-PCR analysis demonstrated that the transcript levels of structural genes associated with anthocyanin biosynthesis were higher in transgenic wheat than the wild-type (WT), which indicated that ThMYC4E activated anthocyanin biosynthesis in the transgenic lines. Correspondingly, the anthocyanin contents in grains, roots, stems, leaves and glumes of transgenic lines were higher than those in the WT. Metabolome analysis demonstrated that the anthocyanins were composed of cyanidin and delphinidin in the grains of the transgenic lines. Moreover, the transgenic lines showed higher antioxidant activity, in terms of scavenging DPPH radicals, in the ethanol extracts of their grains. The overexpression of ThMYC4E sheds light on the traits related to anthocyanin biosynthesis in common wheat and provide a new way to improve anthocyanin content.

HPLC-MS/MS analysis of anthocyanins in human plasma and urine using protein precipitation and dilute-and-shoot sample preparation methods, respectively.

A high-performance liquid chromatography tandem-mass spectrometry (HPLC-MS/MS) method has been developed to analyze anthocyanins in urine and plasma to further understand their absorption, distribution, metabolism and excretion. The method employed a Synergi RP-Max column (250 × 4.6 mm, 4 µm) and an API 4000 mass spectrometer. A gradient elution system consisted of mobile phase A (water-1% formic acid) and mobile phase B (acetonitrile) with a flow rate of 0.60 mL/min. The gradient was initiated at 5% B, increased to 21% B at 20 min, and then increased to 40% B at 35 min. The analysis of anthocyanins presents a challenge because of the poor stability of anthocyanins during sample preparation, especially during solvent evaporation. In this method, the degradation of anthocyanins was minimized using protein precipitation and dilute-and-shoot and sample preparation methods for plasma and urine, respectively. No interferences were observed from endogenous compounds. The method has been used to analyze anthocyanin concentrations in urine and plasma samples from volunteers administered saskatoon berries. Cyanidin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-arabinoside, cyanidin-3-xyloside and quercetin-3-galactoside, the five major flavonoid components in saskatoon berries, were identified in plasma and urine samples.

An LC-MS/MS method for quantitation of cyanidin-3-O-glucoside in rat plasma: Application to a comparative pharmacokinetic study in normal and streptozotocin-induced diabetic rats.

A sensitive and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to determine cyanidin-3-O-glucoside (Cy-3G) in normal and streptozotocin-induced diabetic rat plasma. Chromatographic separation was carried out on a Zorbax SB-C18 (50 × 4.6 mm, 5 µm) column and mass spectrometric analysis was performed using a Thermo Finnigan TSQ Quantum Ultra triple-quadrupole mass spectrometer coupled with an ESI source in the negative ion mode. Selected reaction monitoring mode was applied for quantification using target fragment ions m/z 447.3 → 285.2 for Cy-3G and m/z 463.0 → 300.1 for quercetin-3-O-glucoside (internal standard). The calibration curve was linear over the range 3.00-2700 ng/mL (r2 ≥ 0.99) with the lower limit of quantitation at 3.00 ng/mL. Intra- and inter-day precision was <14.5% and mean accuracy was from -11.5 to 13.6%. Stability testing showed that Cy-3G remained stable during the whole analytical procedure. After validation, the assay was successfully used to support a preclinical pharmacokinetic comparison of Cy-3G between normal and diabetic rats. Results indicated that diabetes mellitus significantly altered the in vivo pharmacokinetic characteristics of Cy-3G after oral administration in rats.

The effect of anthocyanin supplementation in modulating platelet function in sedentary population: a randomised, double-blind, placebo-controlled, cross-over trial.

The anti-thrombotic properties of anthocyanin (ACN) supplementation was evaluated in this randomised, double-blind, placebo (PBO) controlled, cross-over design, dietary intervention trial in sedentary population. In all, sixteen participants (three males and thirteen females) consumed ACN (320 mg/d) or PBO capsules for 28 d followed by a 2-week wash-out period. Biomarkers of thrombogenesis and platelet activation induced by ADP; platelet aggregation induced by ADP, collagen and arachidonic acid; biochemical, lipid, inflammatory and coagulation profile were evaluated before and after supplementation. ACN supplementation reduced monocyte-platelet aggregate formation by 39 %; inhibited platelet endothelial cell adhesion molecule-1 expression by 14 %; reduced platelet activation-dependant conformational change and degranulation by reducing procaspase activating compound-1 (PAC-1) (↓10 %) and P-selectin expression (↓14 %), respectively; and reduced ADP-induced whole blood platelet aggregation by 29 %. Arachidonic acid and collagen-induced platelet aggregation; biochemical, lipid, inflammatory and coagulation parameters did not change post-ACN supplementation. PBO treatment did not have an effect on the parameters tested. The findings suggest that dietary ACN supplementation has the potential to alleviate biomarkers of thrombogenesis, platelet hyperactivation and hyper-aggregation in sedentary population.

Consumption of anthocyanin-rich cherry juice for 12 weeks improves memory and cognition in older adults with mild-to-moderate dementia.

PURPOSE: Dietary flavonoids, including anthocyanins, may positively influence cognition and may be beneficial for the prevention and treatment of dementia. We aimed to assess whether daily consumption of anthocyanin-rich cherry juice changed cognitive function in older adults with dementia. Blood pressure and anti-inflammatory effects were examined as secondary outcomes. METHODS: A 12-week randomised controlled trial assessed cognitive outcomes in older adults (+70 year) with mild-to-moderate dementia (n = 49) after consumption of 200 ml/day of either a cherry juice or a control juice with negligible anthocyanin content. Blood pressure and inflammatory markers (CRP and IL-6) were measured at 6 and 12 weeks. ANCOVA controlling for baseline and RMANOVA assessed change in cognition and blood pressure. RESULTS: Improvements in verbal fluency (p = 0.014), short-term memory (p = 0.014) and long-term memory (p ≤ 0.001) were found in the cherry juice group. A significant reduction in systolic (p = 0.038) blood pressure and a trend for diastolic (p = 0.160) blood pressure reduction was evident in the intervention group. Markers of inflammation (CRP and IL-6) were not altered. CONCLUSION: Inclusion of an anthocyanin-rich beverage may be a practical and feasible way to improve total anthocyanin consumption in older adults with mild-to-moderate dementia, with potential to improve specific cognitive outcomes.

Inhibition of pancreatic cancer cell migration by plasma anthocyanins isolated from healthy volunteers receiving an anthocyanin-rich berry juice.

PURPOSE: Pancreatic cancer is an aggressive cancer type, of which the most important characteristics are migration and metastasis. Anthocyanins (ACN) are discussed to be protective phytochemicals; however, up to now only scarce data are available regarding their effects on cancer prevention. In this study, we aimed to determine whether ACN and their metabolites from plasma (PAM), isolated from blood of healthy volunteers after ingestion of an ACN-rich juice, are effective in modulating cancer cell migration in vitro. METHODS: PAM were isolated from blood of healthy volunteers (n = 10) after consumption of an ACN-rich berry juice. Before ingestion (PAM0min) and after 60 min (PAM60min), blood was taken and PAM were isolated from plasma by solid-phase extraction. Migration of pancreatic cancer cells PANC-1 and AsPC-1 was assayed in a Boyden chamber. The influence of PAM on cellular reactive oxygen species (ROS) or mitochondria-specific ROS was measured fluorimetrically. mRNA expression levels of matrix metalloproteinases (MMP-2 and MMP-9) and NF-κB mRNA were determined by real-time PCR. RESULTS: After application of PAM60min to PANC-1, we observed a reduced cell migration, which was associated with reduced levels of endogenously generated ROS concomitant with reduced NF-κB as well as MMP-2 and MMP-9 mRNA expression levels. In AsPC-1 cells, however, migration was not affected by PAM60min. CONCLUSION: It can be assumed that physiologically relevant ACN and their metabolites were able to inhibit pancreatic cancer cell migration in dependency of the phenotype of cells and may thus deserve further attention as potential bioactive phytochemicals in cancer prevention.

Phytochemical uptake following human consumption of Montmorency tart cherry (L. Prunus cerasus) and influence of phenolic acids on vascular smooth muscle cells in vitro.

PURPOSE: To investigate the phytochemical uptake following human consumption of Montmorency tart cherry (L. Prunus cerasus) and influence of selected phenolic acids on vascular smooth muscle cells in vitro. METHODS: In a randomised, double-blinded, crossover design, 12 healthy males consumed either 30 or 60 mL of Montmorency tart cherry concentrate. Following analysis of the juice composition, venous blood samples were taken before and 1, 2, 3, 5 and 8 h post-consumption of the beverage. In addition to examining some aspects of the concentrate contents, plasma concentrations of protocatechuic acid (PCA), vanillic acid (VA) and chlorogenic (CHL) acid were analysed by reversed-phase high-performance liquid chromatography (HPLC) with diode array for quantitation and mass spectrometry detection (LCMS) for qualitative purposes. Vascular smooth muscle cell migration and proliferation were also assessed in vitro. RESULTS: Both the 30 and 60 mL doses of Montmorency cherry concentrate contained high amounts of total phenolics (71.37 ± 0.11; 142.73 ± 0.22 mg/L) and total anthocyanins (62.47 ± 0.31; 31.24 ± 0.16 mg/L), as well as large quantities of CHL (0.205 ± 0.24; 0.410 ± 0.48 mg/L) and VA (0.253 ± 0.84; 0.506 ± 1.68 mg/L). HPLC/LCMS identified two dihydroxybenzoic acids (PCA and VA) in plasma following MC concentrate consumption. Both compounds were most abundant 1-2 h post-initial ingestion with traces detectable at 8 h post-ingestion. Cell migration was significantly influenced by the combination of PCA and VA, but not in isolation. There was no effect of the compounds on cell proliferation. CONCLUSIONS: These data show new information that phenolic compounds thought to exert vasoactive properties are bioavailable in vivo following MC consumption and subsequently can influence cell behaviour. These data may be useful for the design and interpretation of intervention studies investigating the health effects of Montmorency cherries.

Purified anthocyanin supplementation reduces dyslipidemia, enhances antioxidant capacity, and prevents insulin resistance in diabetic patients.

BACKGROUND: Oxidative stress plays an essential role in the pathogenesis of type 2 diabetes. Anthocyanin, a natural antioxidant, has been reported to reduce oxidative stress and to attenuate insulin resistance and diabetes in animal models; however, the translation of these observations to humans has not been fully tested. OBJECTIVE: This study was designed to investigate the effects of purified anthocyanins on dyslipidemia, oxidative status, and insulin sensitivity in patients with type 2 diabetes. METHODS: A total of 58 diabetic patients were given 160 mg of anthocyanins twice daily or placebo (n = 29/group) for 24 wk in a randomized, placebo-controlled, double-blind trial. Participants and investigators were masked to treatment allocation. RESULTS: Anthocyanin supplementation significantly decreased serum LDL cholesterol (by 7.9%; P < 0.05), triglycerides (by 23.0%; P < 0.01), apolipoprotein (apo) B-48 (by 16.5%; P < 0.05), and apo C-III (by 11.0%; P < 0.01) and increased HDL cholesterol (by 19.4%; P < 0.05) compared with placebo after the 24-wk intervention. In addition, patients in the anthocyanin group showed higher total radical-trapping antioxidant parameter and ferric ion reducing antioxidant power values than did patients in the placebo group (both P < 0.05). Serum concentrations of 8-iso-prostaglandin F2α, 13-hydroxyoctadecadienoic acid, and carbonylated proteins in patients in the anthocyanin group were significantly less than in patients in the placebo group (23.4%, 25.8%; P < 0.01 and 20%; P = 0.022, respectively). Furthermore, supplementation with anthocyanin lowered fasting plasma glucose (by 8.5%; P < 0.05) and homeostasis model assessment for insulin resistance index (by 13%; P < 0.05), and elevated serum adiponectin (by 23.4%; P < 0.01) and ß-hydroxybutyrate (by 42.4%; P = 0.01) concentrations compared with placebo supplementation. CONCLUSION: These findings demonstrate that anthocyanin supplementation exerts beneficial metabolic effects in subjects with type 2 diabetes by improving dyslipidemia, enhancing antioxidant capacity, and preventing insulin resistance. This trial was registered at www.clinicaltrials.gov as NCT02317211.

Uptake and bioavailability of anthocyanins and phenolic acids from grape/blueberry juice and smoothie in vitro and in vivo.

The goal of eating five servings of fruits and vegetables a day has not yet been achieved. The intake of polyphenols such as anthocyanins (ACN) could be improved by consuming smoothies and juices that are increasingly popular, especially in children; however, bioavailability data concerning food matrix effects are scarce. Thus, we conducted a randomised, cross-over, bioavailability study (n 10) to determine the bioavailability of ACN and their metabolites from an ACN-rich grape/blueberry juice (841 mg ACN/litre) and smoothie (983 mg ACN/litre) in vivo, and the uptake of a corresponding grape/blueberry extract in vitro. After the intake of beverage (0·33 litres), plasma and fractionated urine samples were collected and analysed by ultra-performance liquid chromatography coupled to MS. The most abundant ACN found in plasma and urine were malvidin and peonidin as native ACN and as glucuronidated metabolites as well as 3,4-dihydroxybenzoic acid (3,4-DHB); minor ACN (delphinidin, cyanidin and petunidin) were only detected as native glycosides. Plasma pharmacokinetics and recoveries of urinary metabolites of ACN were not different for juice or smoothie intake; however, the phenolic acid 3,4-DHB was significantly better bioavailable from juice in comparison to smoothie. In vitro data with absorptive intestinal cells indicated that despite their weak chemical stability, ACN and 3,4-DHB could be detected at the basal side in their native forms. Whether smoothies as well as juices should be recommended to increase the intake of potentially health-promoting ACN and other polyphenols requires the consideration of other ingredients such as their relatively high sugar content.

Comparison of the postprandial effects of purple-fleshed and yellow-fleshed potatoes in healthy males with chemical characterization of the potato meals.

The aim of the current study was to characterize the anthocyanin content and composition of a purple potato landrace cultivar (Solanum tuberosum 'Synkeä Sakari') and to compare the postprandial effects of purple-fleshed potatoes, yellow-fleshed potatoes and bilberries in potato starch on postprandial glycemia and insulinemia in healthy males. The purple potato meal caused smaller insulinemia than the yellow potato meal (iAUC 120 min 1347 and 2226, respectively, p = 0.012 and iAUC 240 min 1448 and 2403, p = 0.007) or the bilberry meal (iAUC 120 min 1920, p = 0.027). The purple potato meal caused a smaller plasma glucose at 40 min postprandially compared with the yellow potato meal (p = 0.044). The results of this study suggest that anthocyanin-containing purple-fleshed potatoes influence the postprandial insulinemia positively. Since potatoes are the world's largest non-grain commodity, replacing yellow-fleshed potatoes with purple-fleshed potatoes as staple food could have large potential in maintaining public health.

Practical application of flavonoid-poor menu meals to the study of the bioavailability of bilberry anthocyanins in human subjects.

Practical application of flavonoid-poor menus was evaluated on the bioavailability of anthocyanins as model flavonoids. Detectable amounts of flavonoids were not found in plasma and urine collected from 13 participants, who took the menus. After ingesting bilberry anthocyanins (919 µmol), average plasma AUC0-6h, Cmax, Tmax values and urinary recovery were 386.0 nmol h/mL, 139.1 nM, 1.31 h and 0.21%, respectively.

Anthocyanins suppress the cleavable complex formation by irinotecan and diminish its DNA-strand-breaking activity in the colon of Wistar rats.

In the present study, the question was addressed whether anthocyanins interfere with the topoisomerase I poison irinotecan in vivo. In vivo complexes of enzyme to DNA bioassay was used to detect irinotecan-induced stabilization of topoisomerase I/DNA complexes and single cell gel electrophoresis to determine DNA-strand-break induction in the colon of male Wistar rats. Furthermore, analysis of anthocyanin concentrations in rat plasma and rat colon was included in the testing, demonstrating that anthocyanins reach the colon and the concentrations do not differ between rats that only received anthocyanins and the anthocyanin/irinotecan group. Blackberry extract was found to significantly reduce irinotecan-mediated topoisomerase I/DNA cleavable complex formation. Overall, anthocyanins did not notably increase cleavable complex formation. However, a significant increase of DNA damage was shown after a single dose of irinotecan as well as the single compounds cyanidin (cy) and cyanidin-3-glucoside (cy-3-g). Furthermore, a significant reduction of irinotecan-induced DNA-strand breaks after a pretreatment with cy, cy-3-g and blackberry extract was observed. Thus, the question arises whether anthocyanin-rich preparations might interfere with chemotherapy or whether, due to low systemic bioavailability, the preparations might provide protective potential in the gastrointestinal tract.

Anthocyanin kinetics are dependent on anthocyanin structure.

The kinetics of anthocyanin metabolism was investigated in a human feeding trial. Volunteers (n 12) consumed purple carrots containing five anthocyanin forms: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside), cyanidin-3-(xylose-feruloyl-glucose-galactoside) and cyanidin-3-(xylose-coumuroyl-glucose-galactoside). The purple carrots were served as three different treatments in a crossover design with a 3-week washout between treatments. Purple carrot treatments were 250 g raw carrots, 250 g cooked carrots and 500 g cooked carrots. Serial blood and urine samples were collected for 8 and 24 h after the dose, respectively, and analysed for anthocyanins. Of the anthocyanin forms ingested, four were detected in plasma and urine: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside). The time courses of plasma and urine anthocyanin contents were evaluated with compartmental modelling. Results showed that absorption, gastrointestinal transit and plasma elimination are dependent on anthocyanin structure. Absorption efficiencies of acylated compounds (cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside)) were less than those for non-acylated anthocyanins (cyanidin-3-(xylose-glucose-galactoside) and cyanidin-3-(xylose-galactoside)). The acylated anthocyanins exhibited a shorter half-life for gastrointestinal absorption than the non-acylated anthocyanins. Fractional elimination of non-acylated compounds was slower than that for acylated anthocyanins. These results provide the first information about the kinetics of individual anthocyanins in human beings.

Four-week ingestion of blood orange juice results in measurable anthocyanin urinary levels but does not affect cellular markers related to cardiovascular risk: a randomized cross-over study in healthy volunteers.

PURPOSE: Blood orange juice (OJ) is an important source of anthocyanins (ACN). The latter molecules are endowed with antioxidant activity and might thus modulate different cell function. Our aim was to investigate ACN absorption following a 1-month daily supplementation of blood OJ and their potential effects on cell markers of platelet and leukocyte activation and interaction. METHODS: Eighteen healthy subjects (10 men and 8 women) were supplemented for 4 weeks with 1 L/day of either blood OJ or blond OJ (that contains no ACN), following a cross-over design. Blood samples were obtained from fasting participants both at baseline and after each week of treatment to measure plasma ACN concentration. At the same time-intervals, 24-h urinary excretion of these molecules was also measured. At the beginning and the end of each 4-week intervention period, platelet and leukocyte markers and mixed cell conjugates were assessed both in basal condition and upon in vitro collagen/ADP activation. RESULTS: After 1 week supplementation with blood OJ, 24-h urinary excretion of ACN reached average levels of 11.47 ± 5.63 nmol that significantly differed from baseline and remained substantially unchanged until the end of treatment. No plasma accumulation of ACN following blood OJ supplementation was observed. Cellular markers were not significantly affected by either OJ after 4-week supplementation. CONCLUSIONS: Following supplementation of healthy volunteers with 1 L/day of blood OJ for 4 weeks, the ACN plasma levels reached were insufficient to significantly modify cell markers of platelet and leukocyte activation and interaction.

Blueberry anthocyanin intake attenuates the postprandial cardiometabolic effect of an energy-dense food challenge: Results from a double blind, randomized controlled trial in metabolic syndrome participants.

BACKGROUND & AIMS: Whilst the cardioprotective effects of blueberry intake have been shown in prospective studies and short-term randomized controlled trials (RCTs), it is unknown whether anthocyanin-rich blueberries can attenuate the postprandial, cardiometabolic dysfunction which follows energy-dense food intakes; especially in at-risk populations. We therefore examined whether adding blueberries to a high-fat/high-sugar meal affected the postprandial cardiometabolic response over 24 h. METHODS: A parallel, double-blind RCT (n = 45; age 63.4 ± 7.4 years; 64% male; BMI 31.4 ± 3.1 kg/m2) was conducted in participants with metabolic syndrome. After baseline assessments, an energy-dense drink (969 Kcals, 64.5 g fat, 84.5 g carbohydrate, 17.9 g protein) was consumed with either 26 g (freeze-dried) blueberries (equivalent to 1 cup/150 g fresh blueberries) or 26 g isocaloric matched placebo. Repeat blood samples (30, 60, 90, 120, 180, 360 min and 24 h), a 24 h urine collection and vascular measures (at 3, 6, and 24 h) were performed. Insulin and glucose, lipoprotein levels, endothelial function (flow mediated dilatation (FMD)), aortic and systemic arterial stiffness (pulse wave velocity (PWV), Augmentation Index (AIx) respectively), blood pressure (BP), and anthocyanin metabolism (serum and 24 h urine) were assessed. RESULTS: Blueberries favorably affected postprandial (0-24 h) concentrations of glucose (p < 0.001), insulin (p < 0.01), total cholesterol (p = 0.04), HDL-C, large HDL particles (L-HDL-P) (both p < 0.01), extra-large HDL particles (XL-HDL-P; p = 0.04) and Apo-A1 (p = 0.01), but not LDL-C, TG, or Apo-B. After a transient higher peak glucose concentration at 1 h after blueberry intake ([8.2 mmol/L, 95%CI: 7.7, 8.8] vs placebo [6.9 mmol/L, 95%CI: 6.4, 7.4]; p = 0.001), blueberries significantly attenuated 3 h glucose ([4.3 mmol/L, 95%CI: 3.8, 4.8] vs placebo [5.1 mmol/L, 95%CI: 4.6, 5.6]; p = 0.03) and insulin concentrations (blueberry: [23.4 pmol/L, 95%CI: 15.4, 31.3] vs placebo [52.9 pmol/L, 95%CI: 41.0, 64.8]; p = 0.0001). Blueberries also improved HDL-C ([1.12 mmol/L, 95%CI: 1.06, 1.19] vs placebo [1.08 mmol/L, 95%CI: 1.02, 1.14]; p = 0.04) at 90 min and XL-HDLP levels ([0.38 × 10-6, 95%CI: 0.35, 0.42] vs placebo [0.35 × 10-6, 95%CI: 0.32, 0.39]; p = 0.02) at 3 h. Likewise, significant improvements were observed 6 h after blueberries for HDL-C ([1.17 mmol/L, 95%CI: 1.11, 1.24] vs placebo [1.10 mmol/L, 95%CI: 1.03, 1.16]; p < 0.001), Apo-A1 ([1.37 mmol/L, 95%CI: 1.32, 1.41] vs placebo [1.31 mmol/L, 95%CI: 1.27, 1.35]; p = 0.003), L-HDLP ([0.70 × 10-6, 95%CI: 0.60, 0.81] vs placebo [0.59 × 10-6, 95%CI: 0.50, 0.68]; p = 0.003) and XL-HDLP ([0.44 × 10-6, 95%CI: 0.40, 0.48] vs placebo [0.40 × 10-6, 95%CI: 0.36, 0.44]; p < 0.001). Similarly, total cholesterol levels were significantly lower 24 h after blueberries ([4.9 mmol/L, 95%CI: 4.6, 5.1] vs placebo [5.0 mmol/L, 95%CI: 4.8, 5.3]; p = 0.04). Conversely, no effects were observed for FMD, PWV, AIx and BP. As anticipated, total anthocyanin-derived phenolic acid metabolite concentrations significantly increased in the 24 h after blueberry intake; especially hippuric acid (6-7-fold serum increase, 10-fold urinary increase). In exploratory analysis, a range of serum/urine metabolites were associated with favorable changes in total cholesterol, HDL-C, XL-HDLP and Apo-A1 (R = 0.43 to 0.50). CONCLUSIONS: For the first time, in an at-risk population, we show that single-exposure to the equivalent of 1 cup blueberries (provided as freeze-dried powder) attenuates the deleterious postprandial effects of consuming an energy-dense high-fat/high-sugar meal over 24 h; reducing insulinaemia and glucose levels, lowering cholesterol, and improving HDL-C, fractions of HDL-P and Apo-A1. Consequently, intake of anthocyanin-rich blueberries may reduce the acute cardiometabolic burden of energy-dense meals. CLINICAL TRIAL REGISTRY: NCT02035592 at www.clinicaltrials.gov.