Urinary excretion of cyanidin glycosides

Anthocyanins, which are natural plant pigments from the flavonoid family, represent substantial constituents of the human diet. Several fruits (blackcurrant, blue berries, red grape and elderberry) are rich sources of these efficient antioxidant compounds. The present study was designed to determine the potential bioavailability in humans of the anthocyanins of elderberry, mainly cyanidin-3-glucoside and cyanidin-3-sambubioside, and the influence of the simultaneous ingestion of sucrose on the absorption of anthocyanins. Urinary samples from 16 healthy volunteers--8 women and 8 men--were collected before and over a period of 6 h with intervals of 1 h after the ingestion of 11 g elderberry concentrate (containing 1.9 g of anthocyanins equivalent to 235 ml of fresh juice) 1 day diluted with water, the other day with 30 g sucrose. Using high-performance liquid chromatography, it was possible to quantify the two main anthocyanins of elderberry excreted unchanged in the urine (0.003-0.012% of the oral dose). The ingestion of sucrose led to a reduced excretion of anthocyanins.     

Red wine anthocyanins are rapidly absorbed in humans and affect monocyte chemoattractant protein 1 levels and antioxidant capacity of plasma

Epidemiological studies suggest that a moderate consumption of anthocyanins may be associated with protection against coronary heart disease. The main dietary sources of anthocyanins include red-coloured fruits and red wine. Although dietary anthocyanins comprise a diverse mixture of molecules, little is known how structural diversity relates to their bioavailability and biological function. The aim of the present study was to evaluate the absorption and metabolism of the 3-monoglucosides of delphinidin, cyanidin, petunidin, peonidin and malvidin in humans and to examine both the effect of consuming a red wine extract on plasma antioxidant status and on monocyte chemoattractant protein 1 production in healthy human subjects. After a 12-h overnight fast, seven healthy volunteers received 12 g of an anthocyanin extract and provided 13 blood samples in the 24 h following the test meal. Furthermore, urine was collected during this 24-h period. Anthocyanins were detected in their intact form in both plasma and urine samples. Other anthocyanin metabolites could also be detected in plasma and urine and were identified as glucuronides of peonidin and malvidin. Anthocyanins and their metabolites appeared in plasma about 30 min after ingestion of the test meal and reached their maximum value around 1.6 h later for glucosides and 2.5 h for glucuronides. Total urinary excretion of red wine anthocyanins was 0.05+/-0.01% of the administered dose within 24 h. About 94% of the excreted anthocyanins was found in urine within 6 h. In spite of the low concentration of anthocyanins found in plasma, an increase in the antioxidant capacity and a decrease in MCP-1 circulating levels in plasma were observed.     

The Metabolism of Dietary Polyphenols and the Relevance to Circulating Levels of Conjugated Metabolites

Berry extracts rich in anthocyanins have been linked to protective effects including the modulation of age-related neurological dysfunction and the improvement of the resistance of red blood cells against oxidative stress in vitro . In this study the bioavailability, metabolism and elimination of polyphenols from blackcurrant juice, rich in anthocyanins, flavonols, and hydroxycinnamates, were investigated. The four major native anthocyanidin glycosides of blackcurrant juice, delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin-3-glucoside and cyanidin-3-rutinoside, were detected and identified in low amounts by HPLC and LC-MS in plasma and urine post-ingestion. Elimination of the anthocyanins was fast (maximum excretion after 1 h) and plasma levels (0-128.6 nmol/l) and total urinary excretion (0.07-1.35 mg; 0.007-0.133% of the dose ingested) were low. Most significantly, of the hydroxycinnamates, conjugated and free ferulic, isoferulic, p -coumaric, sinapic and vanillic acids were identified in plasma and urine, using GC-MS techniques. Quercetin and kaempferol (as glucuronides) and the proposed colonic metabolite of quercetin, 3-hydroxyphenylacetic acid, were detectable in a minority of subjects. Increased daily urinary hippuric, 4-hydroxyhippuric and 3-hydroxyhippuric acid levels were also observed post-ingestion in all volunteers.     

The metabolism of dietary polyphenols and the relevance to circulating levels of conjugated metabolites

Berry extracts rich in anthocyanins have been linked to protective effects including the modulation of age-related neurological dysfunction and the improvement of the resistance of red blood cells against oxidative stress in vitro . In this study the bioavailability, metabolism and elimination of polyphenols from blackcurrant juice, rich in anthocyanins, flavonols, and hydroxycinnamates, were investigated. The four major native anthocyanidin glycosides of blackcurrant juice, delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin-3-glucoside and cyanidin-3-rutinoside, were detected and identified in low amounts by HPLC and LC-MS in plasma and urine post-ingestion. Elimination of the anthocyanins was fast (maximum excretion after 1 h) and plasma levels (0-128.6 nmol/l) and total urinary excretion (0.07-1.35 mg; 0.007-0.133% of the dose ingested) were low. Most significantly, of the hydroxycinnamates, conjugated and free ferulic, isoferulic, p -coumaric, sinapic and vanillic acids were identified in plasma and urine, using GC-MS techniques. Quercetin and kaempferol (as glucuronides) and the proposed colonic metabolite of quercetin, 3-hydroxyphenylacetic acid, were detectable in a minority of subjects. Increased daily urinary hippuric, 4-hydroxyhippuric and 3-hydroxyhippuric acid levels were also observed post-ingestion in all volunteers.     

Gastrointestinal stability and bioavailability of (poly)phenolic compounds following ingestion of Concord grape juice by humans

The in vitro gastrointestinal stability of (poly)phenolic compounds in Concord grape juice was compared with recoveries in ileal fluid after the ingestion of the juice by ileostomists. Recoveries in ileal fluid indicated that 67% of hydroxycinnamate tartarate esters, and smaller percentages of the intake of other (poly)phenolic compounds, pass from the small intestine to the colon. The juice was also ingested by healthy subjects with an intact functioning colon. Peak plasma concentrations (C(max) ) ranged from 1.0 nmol/L for petunidin-3-O-glucoside to 355 nmol/L for dihydrocoumaric acid. Urinary excretion, as an indicator of bioavailability, varied from 0.26% for total anthocyanins to 24% for metabolites of hydroxycinnamate tartarate esters. The C(max) times of the anthocyanins indicated that their low level absorption occurred in the small intestine in contrast to hydroxycinnamate metabolites which were absorbed in both the small and the large intestine where the colonic microflora appeared responsible for hydrogenation of the hydroxycinnamate side chain. The bioavailability of the complex mixture of (poly)phenolic compounds in Concord grape juice, was very similar to that observed in previous studies when compounds were either fed individually or as major components in products containing a restricted spectrum of (poly)phenolic compounds.     

Urinary excretion of anthocyanins in humans after cranberry juice ingestion

Cranberry, which is rich in polyphenols, including anthocyanins and proanthocyanidins, has been found to have various effects beneficial to human health, including prevention of urinary tract infections. These effects have been associated with polyphenols in the fruit. We investigated the excretion of anthocyanins in human urine after ingestion of cranberry juice. Eleven healthy volunteers consumed 200 ml of cranberry juice containing 650.8 microg total anthocyanins. Urine samples were collected within 24 h before and after consumption. Six of 12 anthocyanins identified in cranberry were quantified in human urine by HPLC coupled with electrospray ionization and tandem mass spectrometry (HPLC-ESI-MS-MS). Among these, peonidin 3-O-galactoside, the second most plentiful anthocyanin in the juice, was found most abundantly in urine within 24 h, corresponding to 41.5 nmol (56.1% of total anthocyanins). The urinary levels of anthocyanins reached a maximum between 3 and 6 h after ingestion, and the recovery of total anthocyanins in the urine over 24 h was estimated to be 5.0% of the amount consumed. This study found high absorption and excretion of cranberry anthocyanins in human urine.     

Absorption of isoflavones in humans: effects of food matrix and processing

If soy isoflavones are to be effective in preventing or treating a range of diseases, they must be bioavailable, and thus understanding factors which may alter their bioavailability needs to be elucidated. However, to date there is little information on whether the pharmacokinetic profile following ingestion of a defined dose is influenced by the food matrix in which the isoflavone is given or by the processing method used. Three different foods (cookies, chocolate bars and juice) were prepared, and their isoflavone contents were determined. We compared the urinary and serum concentrations of daidzein, genistein and equol following the consumption of three different foods, each of which contained 50 mg of isoflavones. After the technological processing of the different test foods, differences in aglycone levels were observed. The plasma levels of the isoflavone precursor daidzein were not altered by food matrix. Urinary daidzein recovery was similar for all three foods ingested with total urinary output of 33-34% of ingested dose. Peak genistein concentrations were attained in serum earlier following consumption of a liquid matrix rather than a solid matrix, although there was a lower total urinary recovery of genistein following ingestion of juice than that of the two other foods.     

Why are grape/fresh wine anthocyanins so simple and why is it that red wine color lasts so long?

Vitis vinifera red berries are characterized by anthocyanins whose chemical structures are among the simplest encountered in higher plants. On the contrary, many plants, including orchids, petunias, red cabbage, elderberries, potatoes for instance, have developed very complicated anthocyanins featuring side-chains at the available positions of the aglycone skeleton. Such pigments were shown to possess bio-physico-chemical properties not to be seen with the grape common anthocyanins. Among beverages (water, tea, beer, wine, coffee, juices, milk), red wine is the only one whose organoleptic properties improve with time and this is called ageing. The grape/fresh red wine pigments, after a few months, disappear from the wine giving birth to new pigments resulting from the wine spontaneous chemistry allowing it to remain red for many years. What are the wine pigments and why are they so stable is the purpose of this mini-review. The structural simplicity of grape anthocyanins and the long lasting colour of red wine is another French paradox; we call it French paradox II.     

Red wine polyphenols, in the absence of alcohol, reduce lipid peroxidative stress in smoking subjects

Phenolic compounds in red wine can exert antioxidant effects on in vitro lipoprotein oxidation. This has led to speculation that red wine consumption mediates unique anti-atherosclerotic effects compared to other alcoholic beverages. However, studies assessing the effects of red wine consumption on lipoprotein oxidation ex vivo have not been conclusive. The recent identification of the F2-isoprostanes as oxidative products of arachidonic acid has provided a reliable measure of in vivo lipid peroxidation. This randomized trial investigated changes in plasma and urinary F2-isoprostane concentrations following red wine, white wine, or dealcoholized red wine consumption in humans. Eighteen male smokers consumed, in random order, red wine, white wine, or dealcoholized red wine, for two weeks with one week washout between beverages. Plasma and urinary F2-isoprostane concentrations were measured before and after each beverage. Serum gamma-glutamyl transpeptidase (gamma-GT) and urinary 4-O -methylgallic acid were measured as markers of alcohol consumption and phenolic acid absorption, respectively. Plasma F2-isoprostanes (p < .05) decreased significantly with dealcoholized red wine but not with the alcohol-containing beverages. Urinary excretion of F2-isoprostanes showed a similar trend. gamma-GT decreased significantly with dealcoholized red wine and increased with both alcohol-containing beverages (p < .01). Urinary excretion of 4-O-methylgallic acid increased significantly (p < .001) in the 24 h urine samples following red wine or dealcoholized red wine ingestion, but not with white wine. Serum urate increased and beta-carotene decreased with both alcoholic beverages relative to dealcoholized red wine. There was no change in the antioxidants alpha- and gamma-tocopherol or vitamin C with any of the beverages. The results suggest that polyphenols in dealcoholized red wine can reduce in vivo lipid peroxidation as measured by F2-isoprostanes in smoking subjects. However, no reduction in lipid peroxidation was observed following red or white wine consumption, suggesting that any protective effects of wine drinking on cardiovascular disease are unlikely to be related to inhibition of lipid oxidation.     

Impact of leaf removal as a source of stresses on grapevine yields,chemical characteristics,and anthocyanin content in the grapevine variety Babica

Leaf removal (LR) treatments improve the photosynthetic capacity of the remaining leaves and induce flavonoid synthesis as a stress response in the common grapevine (Vitis vinifera L.). However, excessive exposure of grape berries to UV-B radiation as a result of cultural practices in the Mediterranean climate may have negative effects on berry composition. This 2-year study determined the effects of defoliation on the autochthonous red grape variety ‘Babica’ in a Mediterranean climate (wine-growing region Dalmatia, Croatia). Six leaves were removed before flowering (FLR) and at the end of véraison (the onset of grape ripening; VerLR) and were compared to the untreated control. Yield parameters, sugar content, grape must pH, total polyphenols (TP), total anthocyanin (TA) content, and individual anthocyanin compounds were measured in grape skin extracts and wines. However, the greater mean daily temperature during the vegetation period and lesser rainfall before harvest in 2018 increased yield per vine, average cluster weights, density, and total acidity, compared to 2017. Both defoliation treatments significantly reduced TP in grape extracts, but these differences were not observed in wine. Compared to the control (NLR), VerLR treatment significantly reduced TA in grape skin extracts and wine. Significantly lesser TP concentrations, in grape skin extracts and wine, as well as TA were noticed during the 2017 season. VerLR treatment reduced the concentration of nine individual anthocyanins compared to the control in grape skin extracts, while this effect was not observed in wine. Season year was a statistically significant source of variability of the individual anthocyanin contents in wine. Under specific environmental conditions LR can decrease polyphenols, especially anthocyanins, and negatively impact grape and wine quality.     

Dietary factors affecting the urinary mutagenicity assay system. II. The absence of mutagenic activity in human urine following consumption of red wine or grape juice

The mutagenic activity of urine samples from nonsmoking individuals before and after the consumption of either red wine or grape juice was determined. Urine samples collected from individuals on liquid or regular diets were concentrated using XAD-2 resin. No mutagenic activity of urine concentrates was detected with Salmonella tester strains TA98 or TA100 with or without microsomal activation. The addition of 1000 units of beta-glucuronidase into the agar overlay did not show any mutagenic activity. The mutagens in red wine and grape juice, however, were extracted using the XAD-2 column. Concentrates of urine samples spiked with either of the two extracts exhibited mutagenic activity.     

Anthocyanins from red wine--their stability under simulated gastrointestinal digestion

The stability of anthocyanins from red wine was assessed using an in vitro digestion system that simulated the physiochemical changes that occur in the upper gastrointestinal tract. Anthocyanins in red wine were stable to gastric conditions whereas there was a small loss in total phenol content. After pancreatic digestion, the total anthocyanins were very poorly recovered compared to the bulk phenols in the IN sample, which was previously described as the "serum-available" fraction, and the majority of the anthocyanins and phenols were recovered in the OUT fraction, previously described as the "colon-available" fraction. Removing alcohol from the wine samples prior to the procedure did not markedly affect this pattern. The composition of anthocyanins in the post gastric, IN and OUT samples was analysed using liquid chromatography mass-spectrometry. The red wine used contained over 20 identifiable anthocyanins of which the main components were 3-O-glucosides of malvidin, peonidin, petundin, delphidin and cyanidin. Coumaroylated-glucoside derivatives of malvidin, petundin, peonidin, and delphinidin were observed and acetylated glucosides of peonidin, petundin and malvidin were also identified. Anthocyanins with modified aglycones similar to vitisin A derivatives of delphinidin, peonidin, petunidin and malvidin were also identified. After the in vitro digestion procedure, only five anthocyanins could be detected in the IN (serum-available) and the OUT (colon-available) fractions, which were confirmed as malvidin-3-O-glucoside and the vitisin A adducts of malvidin-3-O-glucoside, malvidin-3-O-acetylglucoside, malvidin-3-O-coumaroylglucoside and peonidin-3-O-glucoside. Malvidin-3-O-glucoside was recovered at 0.2% in the IN fraction and 0.9% in the OUT fraction. However, the vitisin derivatives were much more stable to pancreatic digestion. Assuming that the vitisin A derivatives display similar biological properties to their parent anthocyanins, their enhanced gastrointestinal stability could lead to enhanced bioavailability and bio-effectiveness in vivo.     

Antioxidant effect of red wine anthocyanins in normal and catalase-inactive human erythrocytes

Previous studies reported that aged red wine, but not novel red wine or white wine protects human red blood cells from oxidative damage induced in vitro by H(2)O(2.) Here, we demonstrate that the beneficial properties of aged red wine are due, at least in part, to the presence of anthocyanins. We firstly measured the "antioxidant power" of an Italian red wine (Taurasi, Avellino) and that of its anthocyanin fractions by using Ferric Reducing Antioxidant Power Assay. Subsequently, we demonstrate that fractions containing anthocyanins lower ROS (reactive oxygen species) and methemoglobin production in human erythrocytes treated with H(2)O(2.) Finally, we reported that the protective effects of anthocyanins were also confirmed in an experimental model in which RBCs were deprived of catalase activity by treatment with 4 mM sodium azide. The results obtained clearly demonstrate that red wine anthocyanins protect human RBCs from oxidative stress.     

The distribution of mutagenic activity in red, rose and white wines

Using a modified Salmonella typhimurium TA98 Ames-test system, more than 150 red, white and rose wines were analyzed for direct-acting and microsomal enzyme-enhanced mutagenic activity. The following conclusions were reached from analysis of this wine mutagenicity data base. White and rose wines, as well as grape juices, exhibited little or no detectable direct-acting or microsomal enzyme-enhanced mutagenic activity. However, red wine samples contained highly variable amounts of mutagens, ranging from undetectable to levels 30-fold above the sensitivity limit of the assay system. The variations in red wine mutagenicity were unrelated to grape variety, vintage, aging methods or production region. Hence, individual winery production practices must represent the most significant contribution to the variations observed.     

Anthocyanin Profiles in Grape Berry Skins of Different Species of Wine Grapes in Shanxi,China

To understand the anthocyanin characteristics of wine grape varieties, the anthocyanin composition and content of 31 wine grape varieties were analyzed to explore the use of anthocyanins as chemical fingerprints to distinguish varieties. Results showed that a total of 21 anthocyanins were detected in the skins, including cyanidin, delphinidin, petunidin, peonidin and malvidin 3-monoglucosides (or 3,5-diglucosides) along with the corresponding acetyl and p-coumaroyl derivatives. The highest and lowest total amount of anthocyanins were detected in ‘Ruby Cabernet’ and ‘Muscat Rouge’, respectively. In the 21 Vitis vinifera grapes, there were 3~11 monoglucoside anthocyanins detected, however, there were 4 to 9 monoglucoside anthocyanins and 1~7 diglucoside anthocyanins detected in the 10 other species of grapes. Except for ‘Zhesexiang’ ‘Seibel Noir’, ‘44-6-7-1’ and ‘Beibinghong’, the contents of diglucoside anthocyanins in the other six varieties accounted for more than 52% of the total anthocyanins. Except for ‘Zhesexiang’, ‘Muscat Rouge’ and ‘Beibinghong’, the content of methylated anthocyanins accounted for more than 75% of total anthocyanins. There were significant differences in the anthocyanin types and contents in the skins among V. vinifera and other grapes. The results of the principal component analysis and the cluster classification of 31 grape varieties (lines) were nearly consistent, which suggested that anthocyanins can be used as chemical fingerprints to distinguish wine grape varieties.     

The effect of consumption of purple grape juice in the gestational period on oxidative stress parameters in Wistar rat foetuses

This study aimed to evaluate the effects of purple grape juice consumption in pregnancy on oxidative stress parameters in Wistar rat fetuses. Twenty-four pregnant rats were divided into five groups: control group, indomethacin group (received a single dose of indomethacin in DG20), group grape juice DG14 (received an amount for 14 days/first and second gestational trim), group grape juice DG20 (received a dose throughout the gestational period), group grape juice two doses (received two doses, at morning and afternoon). On the 20th day of pregnancy (DG20), rats were anesthetized, and a cesarean section was performed to obtain the fetuses. A sample of liver, heart, and total brain of fetuses was collected for oxidative stress analyses. Values P<0.05 were considered significant. In fetuses’ heart, we observed that the grape juice two dose group decreased sulfhydryl and increased SOD. In the liver, the grape juice decreased TBARS and SOD. There was a decrease in carbonyl and sulfhydryl in the indomethacin and grape juice one dose groups in the brain. We conclude that indomethacin altered oxidative stress parameters only in the fetal brain, and grape juice was presented as an important modulator of antioxidant capacity when consumed in a dose.     

Silicic acid: its gastrointestinal uptake and urinary excretion in man and effects on aluminium excretion

Silicon (Si), as silicic acid, is suggested to be the natural antidote to aluminium (Al) toxicity, and was recently shown to promote the urinary excretion of Al from body stores. The metabolism of Si in man, however, remains poorly investigated. Here we report on the pharmacokinetics and metabolism of Si in healthy volunteers following ingestion of orthosilicic acid (27-55 mg/l Si) in water. We also investigated whether orthosilicic acid promotes the urinary excretion of endogenous Al. Minimum, median uptake of Si from the ingested dose was 50.3% (range: 21.9-74.7%, n = 8) based on urinary analysis following dosing. Significant correlations were observed between creatinine clearance and Si levels in serum or urine (r = 0.95 and 0.99, respectively). Renal clearance of Si was 82-96 ml/min suggesting high renal filterability. These results suggest that orthosilicic acid is readily absorbed from the gastrointestinal tract of man and then readily excreted in urine. There was no significant increase in Al excretion, over 32 h, following ingestion of the orthosilicic acid dose (P = 0.5; n = 5).     

Potential mechanisms of cancer chemoprevention by anthocyanins

Anthocyanins are the chemical components that give the intense color to many fruits and vegetables, such as blueberries, red cabbages and purple sweet potatoes. Epidemiological investigations have indicated that the moderate consumption of anthocyanin products such as red wine or bilberry extract is associated with a lower risk of cardiovascular disease and improvement of visual functions. Recently, there is increasing interesting in the pharmaceutical function of anthocyanins. This review summarizes current knowledge on the various molecular evidences of cancer chemoprevention by anthocyanins. These mechanisms can be subdivided into the following aspects: 1) the antioxidation; 2) the molecular mechanisms involved in anticarcinogenesis; 3) the molecular mechanisms involved in the apoptosis induction of tumor cells. Finally, the bioavailability and structure-activity relationship of anthocyanins are also summarized.     

Effects of alcohol on the major steps of reverse cholesterol transport

The effects of moderate alcohol consumption on the capacity of blood sera to promote acceptance of cholesterol (C) from Fu5AH hepatoma cells, esterification of delivered free C, and transfer of produced cholesteryl esters to apolipoprotein (apo) B-containing lipoproteins have been studied. Twenty male subjects with relatively high (>50 mg/dl, n = 10) and low (<50 mg/dl, n = 10) high density lipoprotein (HDL) C levels consumed for eight weeks red grape wine (0.3 g ethanol/kg body mass per day). Alcohol consumption reduced total C and low density lipoprotein C levels in both groups of subjects. Low HDL C subjects showed an increase in HDL C, apo AI, apo AII, and lipoprotein (Lp) AI particle levels after alcohol consumption. Alcohol did not affect free C efflux from the cells. However, after the following period of substitution of alcohol with an isocaloric amount of red grape juice, cellular C efflux markedly reduced. While lecithin:cholesterol acyltransferase (LCAT) activity increased during alcohol consumption only in subjects with low HDL C, high HDL C subjects showed a significant decrease in cholesteryl ester transfer protein (CETP) activity. At the same time, alcohol consumption reduced the endogenous C esterification rate and increased the transfer of endogenous cholesteryl esters to apo B-containing lipoproteins in both groups. Thus, alcohol consumption in moderate doses enhanced the anti-atherogenicity of the serum lipoprotein spectrum, supporting more effective C efflux from peripheral cells and transport of accepted C to apo B-containing lipoproteins. The effects of alcohol on the reverse cholesterol transport depend on the initial HDL C level.     

A low-cost procedure for production of fresh autochthonous wine yeast

A low-cost procedure was designed for easy and rapid response-on-demand production of fresh wine yeast for local wine-making. The pilot plant produced fresh yeast culture concentrate with good microbial quality and excellent oenological properties from four selected wine yeasts. The best production yields were obtained using 2% sugar beet molasses and a working culture volume of less than 60% of the fermenter capacity. The yeast yield using 2% sugar grape juice was low and had poor cell viability after freeze storage, although the resulting yeast would be directly available for use in the winery. The performance of these yeasts in commercial wineries was excellent; they dominated must fermentation and improved its kinetics, as well as improving the physicochemical parameters and the organoleptic quality of red and white wines.