Predictive models built upon annotated and validated intake biomarkers in urine using paired or unpaired analysis helped to classify cranberry juice consumers in a randomized, double-blinded, placebo-controlled, and crossover study.

Intake biomarkers of cranberry juice in women can assess consumption in clinical trials. Discriminant biomarkers in urine may explain urinary tract infection (UTI) preventive activities. We hypothesized that validated and annotated discriminant metabolites in human urine could be used as intake biomarkers in building predictive multivariate models to classify cranberry consumers. Urine samples were collected from 16 healthy women aged 18 to 29 years at baseline and after 3- and 21-day consumption of cranberry or placebo juice in a double-blind, crossover study. Urine metabolomes were analyzed using ultra high-performance liquid chromatography coupled with Orbitrap mass spectrometry. Paired and unpaired multivariate analyses were used to annotate or identify discriminant metabolic features after cranberry consumption. Twenty-six discriminant metabolic features (paired analysis) and 27 (unpaired analysis) after cranberry consumption in an open-label intervention were rediscovered in the blinded study. These metabolites included exogenous (quinic acid) and endogenous ones (hippuric acid). The paired analysis showed better model fitting with partial least-square discriminant analysis models built on all metabolites than the unpaired analysis. Predictive models built on shared metabolites by the unpaired analysis were able to classify cranberry juice consumers with 84.4% to 100% correction rates, overall better than the paired analysis (50%-100%). The double-blind study validated discriminant metabolites from a previous open-label study. These urinary metabolites may be associated with the ability of cranberries to prevent UTIs and serve as potential cranberry intake biomarkers. It reveals the importance of selecting the right predictive models to classify cranberry consumers with higher than 95% correction rates.

Emulsification by vitamin E TPGS or Quillaja extract enhanced absorption of berberine without affecting its metabolism in humans.

Berberine is widely used for the prevention of cancers and diabetes. However, the absorption rate of berberine is less than 1% in humans. The objective of this research was to determine whether emulsification improves the absorption and affects the metabolism of orally ingested berberine. Twelve healthy subjects, both men and women, received 800 mg berberine in a powder or emulsified form by vitamin E TPGS or Quillaja extract using a randomized crossover design. Blood samples were collected 12 hours after a dose. Berberine and its metabolites in plasma were analyzed with and without hydrolysis by glucuronidase and sulfatase on UHPLC-MS/MS. The area under the curve (AUC0-12 h) and peak plasma concentration (Cmax) of berberine was 6.7 nM h and 0.9 nM in participants who received berberine powder. They were increased to 12.6 nM h and 2.0 nM by TPGS emulsification and 28.0 nM h and 5.1 nM by Quillaja extract emulsification, respectively. Berberrubine and demethyleneberberine were detected as major phase-1 metabolites of berberine. The AUC0-12 of both free and total berberrubine was significantly increased by TPGS and Quillaja extract. Emulsification by Quillaja extract was more effective than TPGS to increase the plasma concentrations of free and total demethyleneberberine. However, the ratios of phase-1 metabolites and ratios of phase-2 conjugates were not affected by emulsification. Absorption increases of berberine by TPGS or Quillaja extract emulsification may lead to enhanced bioactivity in humans.

Extracts of Dracocephalum tanguticum Maxim Ameliorate Acute Alcoholic Liver Disease via Regulating Transcription Factors in Mice.

Alcoholic liver disease (ALD) caused by excessive drinking is a health and economic concern worldwide. Given the high morbidity, mortality, and the progressive nature of ALD, finding effective interventions is essential. Previous studies have confirmed that edible food plants and their bioactive compounds exert a protective effect against ALD. Dracocephalum tanguticum Maxim (DTM) is one of the important traditional Tibetan medicines in China with the effect of clearing away liver heat, used for the treatment of hepatitis. In this study, the DTM chloroform extract (DtM-C), ethyl acetate extract (DtM-E), and n-butanol extract (DtM-B) were obtained by ethanol extraction combined with fractional extraction. Acute ALD was induced in mice given intragastric ethanol. Serum and liver biochemical markers were detected by ELISA. Liver histological observation, Oil Red O, and Masson's trichrome staining were performed. Liver injury cells were induced by ethanol. The cell vitality was detected by using MTT colorimetry. The expressions of Nrf2, NF-κB, STAT3, AP-1, CREB, HIF-1α, HO-1, NQO-1, GSTA1, IKB2, and Keap1 were detected by real-time polymerase chain reaction (PCR) to elucidate the mechanism of hepatoprotective effect, and the results were verified by using Western blot. The results of serum liver function indicators (ALT, AST, and ADH), serum hepatic lipid indicators (TC, TG, HDL-C, and LDL-C), and lipid peroxidation indicators (ADH, MDA, SOD, CAT, and GSH-Px) in liver tissue and liver histological observation showed that DtM-E could improve liver function, alleviate fatty degeneration, edema, cell necrosis, and liver fibrosis caused by alcohol. DtM-E also increased the vitality of EtOH-induced liver injury cells, upregulated the mRNA expression of Nrf2, HO-1, NQO-1, and GSTA1, while downregulated the expression of Keap-1, p65, and NF-κB. Western blot results were consistent with PCR. The results suggest that DtM-E has a protective effect against ALD in vitro and in vivo, and its mechanism of action may be related to the activation of Nrf2/Keap-1 and inhibition of the P65/NF-κB signaling pathways.

Ultrasound-assisted extraction of phenolic acids, flavonols, and flavan-3-ols from muscadine grape skins and seeds using natural deep eutectic solvents and predictive modelling by artificial neural networking.

The objective of this study was to investigate the extraction efficiency of 9 natural deep eutectic solvents (NDES) with the assistance of ultrasound for phenolic acids, flavonols, and flavan-3-ols in muscadine grape (Carlos) skins and seeds in comparison to 75% ethanol. Artificial neural networking (ANN) was applied to optimize NDES water content, ultrasonication time, solid-to-solvent ratio, and extraction temperature to achieve the highest extraction yields for ellagic acid, catechin and epicatechin. A newly formulated NDES (#1) consists of choline chloride: levulinic acid: ethylene glycol 1:1:2 and 20% water extracted the highest amount of ellagic acid in the skin at 22.1 mg/g. This yield was 1.73-fold of that by 75% ethanol. A modified NDES (#3) consisting of choline chloride: proline: malic acid 1:1:1 and 30% water extracted the highest amount of catechin (0.61 mg/g) and epicatechin (0.89 mg/g) in the skin, and 2.77 mg/g and 0.37 mg/g in the seed, respectively. The optimal yield of ellagic acid in the skin using NDES #1 was 25.3 mg/g (observed) and 25.3 mg/g (predicted). The optimal yield of (catechin + epicatechin) in seed using NDES #3 was 9.8 mg/g (observed) and 9.6 mg/g (predicted). This study showed the high extraction efficiency of selected NDES for polyphenols under optimized conditions.

[A novel flavanone from Thymus przewalskii].

This study was to investigate the chemical constituents from the aerial parts of Thymus przewalskii. The chemical consti-tuents were separated and purified by column chromatography on silica gel, ODS, Sephadex LH-20 and semi-prepared HPLC, and their structures were determined by physicochemical properties and spectroscopic data. Four flavanones were isolated from the ethanol extract of the aerial parts of T. przewalskii, and identified as(2S)-5,6-dihydroxy-7,8,4'-trimethoxyflavanone(1), 5,4'-dihydroxy-6,7-dimethoxyflavanone(2),(2S)-5,4'-dihydroxy-7,8-dimethoxyflavanone(3), sakuranetin(4), respectively. Compound 1 was a new compound and its configuration was determined by CD spectrum, compound 3 was natural product which was isolated for the first time and their configurations were determined by CD spectra. Compound 2 was isolated from the genus Thymus for the first time and compound 4 was isolated from T. przewalskii for the first time. Furthermore, cytotoxicity test was assayed for the four flavanones. They exhibited weak cytotoxicity against human lung cancer cells(A549), with the IC_(50) from 74.5 to 135.6 µmol·L~(-1).

American cranberries and health benefits - an evolving story of 25 years.

Cranberries contain various types of bioactive components. Scientists have been studying cranberries' beneficial effects on urinary tract health since the 20th century. In the 21st century, the protection provided by cranberry phytochemicals against cancer and vascular diseases has drawn more attention from researchers. Anthocyanins, procyanidins, and flavonols in cranberries were all documented to have potential effects on cancer prevention. The cardiometabolic effects of cranberries have been investigated in several clinical trials. It was found that cranberries positively affect atherosclerotic cholesterol profiles and that they reduced several cardiometabolic risk factors. Nowadays, growing evidence suggests other important roles of cranberries in maintaining digestive health. Cranberry juice or cranberries have been shown to inhibit the colonization of H. pylori in stomach, and protect against intestinal inflammation. For future research, clinical trials with improved study design are urgently needed to demonstrate cranberries' benefits on urinary tract health and cardiometabolic diseases. Hypothesis-driven studies using animals or cell culture are needed to elucidate the mechanisms of cranberries' effects on digestive health. © 2018 Society of Chemical Industry.

[Effect of dihydroartemisinin on permeability of human erythrocyte membrane infected plasmodium].

In view of the fact that the antimalarial effects of artemisinins are significant but the mechanism has not yet been clarified and there are many different opinions, it is possible that artemisinins can produce high anti-malarial efficacy through various mechanisms and multiple pathways. In addition, the researches on the pathogenesis of malaria "erythrocyte membrane plasmodial surface anion channel (PSAC)" in the past few years have provided more positive findings, which may confirm and discover the new antimalarial mechanism of artemisinins. This paper was as to study the effect of dihydroartemisinin (DHA) in vitro on erythrocyte membrane permeability of HB3 plasmodium infection, with using the mechanism of 5% sorbitol can be used to kill the Plasmodium falciparum in red blood cell membrane selectively, the effectual difference of sorbitol on the killing of P. falciparum with adding DHA or not was detected, so as to investigate whether DHA can affect the permeability of the erythrocyte membrane. Result showed that, Pre-stimulation with 10 nmol·L⁻¹ DHA (the final concentration of plasmodium in vitro culture system) for 30 min could significantly decrease the killing effect of sorbitol on the HB3 plasmodium in the P. falciparum erythrocytic cycle, and DHA may inhibit the permeability of the erythrocyte membrane for preventing sorbitol through the red blood cell membrane, thereby reducing the killing effect of sorbitol on the P. falciparum.

Static, Kinetic, and Isotherm Adsorption Performances of Macroporous Adsorbent Resins for Recovery and Enrichment of Bioactive Procyanidins from Cranberry Pomace.

This study examined the ability of five Amberlite resins coupled with ultrasound-assisted water extraction for the recovery and enrichment of bioactive procyanidins and total phenolics from cranberry pomace. Static adsorption showed that XAD-7HP had the highest adsorption capacity for procyanidins (52.2 mg/g resin) and total phenolics (99.1 mg/g resin) whereas XAD-761 had the lowest. Adsorption of procyanidins fitted better to pseudo-second-order kinetics than pseudo-first-order kinetics. Isotherm adsorption on XAD-7HP suggested that Langmuir isotherm was a better model to describe the adsorption of procyanidins while Kemkin-Pyzhev equation was better for total phenolics based on higher coefficient of determinations (R2 ). Dynamic tests on XAD-7HP suggested that the flow rate of 7 and 8 mL/min were the optimum conditions for adsorption and desorption of procyanidins, respectively. Measurements using HPLC revealed that adsorption increased the contents of procyanidins and total phenolics by 4.57- and 4.73-folds, respectively, compared to the initial extracts. This research showed that Amberlite XAD-7HP resin adsorption coupled with ultrasound-assisted water extraction is an efficient method to separate and concentrate procyanidins from cranberry pomace.

Mathematical modeling of the adsorption/desorption characteristics of anthocyanins from muscadine (Vitis rotundifolia cv. Noble) juice pomace on Amberlite FPX66 resin in a fixed bed column.

BACKGROUND: Muscadine grape pomace, a by-product of juicing and wine-making, contains significant amounts of anthocyanin 3,5-diglucosides, known to be beneficial to human health. RESULTS: The objective of this research was to use mathematical modeling to investigate the adsorption/desorption characteristics of these anthocyanins from muscadine grape pomace on Amberlite FPX66 resin in a fixed bed column. Anthocyanins were extracted using hot water and ultrasound, and the extracts were loaded onto a resin column at five bed depths (5, 6, 8, 10 and 12 cm) using three flow rates (4, 6 and 8 mL min-1 ). It was found that adsorption on the column fitted the bed depth service time (BDST) model and the empty bed residence time (EBRT) model. Desorption was achieved by eluting the column using ethanol at four concentrations (25, 40, 55 and 70% v/v) and could be described with an empirical sigmoid model. The breakthrough curves of anthocyanins fitted the BDST model for all three flow rates with R2 values of 0.983, 0.992 and 0.984 respectively. The EBRT model was successfully employed to find the operating lines, which allow for column scale-up while still achieving similar results to those found in a laboratory operation. Desorption with 40% (v/v) ethanol achieved the highest recovery rate of anthocyanins at 79.6%. CONCLUSION: The mathematical models established in this study can be used in designing a pilot/industrial- scale column for the separation and concentration of anthocyanins from muscadine juice pomace. © 2018 Society of Chemical Industry.

Development of a Thiolysis HPLC Method for the Analysis of Procyanidins in Cranberry Products.

The objective of this study was to develop a thiolysis HPLC method to quantify total procyanidins, the ratio of A-type linkages, and A-type procyanidin equivalents in cranberry products. Cysteamine was utilized as a low-odor substitute of toluene-α-thiol for thiolysis depolymerization. A reaction temperature of 70 °C and reaction time of 20 min, in 0.3 M of HCl, were determined to be optimum depolymerization conditions. Thiolytic products of cranberry procyanidins were separated by RP-HPLC and identified using high-resolution mass spectrometry. Standards curves of good linearity were obtained on thiolyzed procyanidin dimer A2 and B2 external standards. The detection and quantification limits, recovery, and precision of this method were validated. The new method was applied to quantitate total procyanidins, average degree of polymerization, ratio of A-type linkages, and A-type procyanidin equivalents in cranberry products. Results showed that the method was suitable for quantitative and qualitative analysis of procyanidins in cranberry products.

Mitigation effects of proanthocyanidins with different structures on acrylamide formation in chemical and fried potato crisp models.

Proanthocyanidins with different structures were prepared from three condensed tannin-rich plant materials and then characterized using HPLC-ESI-MS coupled with thiolysis and MALDI-TOF MS. Their effects on acrylamide formation in asparagine-glucose models and fried potato crisps were determined. Results showed that all proanthocyanidins significantly and dose dependently mitigated acrylamide formation at concentrations of 50, 100 and 200 µg/mL in chemical model system. Using the food model, acrylamide formation were inhibited when potato crisps were soaked in 0.01-1 mg/mL proanthocyanidin solutions for 15 min at room temperature before frying. Proanthocyanidins reduced up to 44.2% of the acrylamide level as concentration was increased to 0.1 mg/mL, whereas higher concentration resulted in a decrease of inhibition. B-type proanthocyanidins had stronger inhibitory activity than A-type. Unit composition and DP had nearly no effect on their inhibitory activity based on same mass. This study showed that proanthocyanidins with various structures were promising additives to mitigate harmful acrylamide.

Aconitine: A potential novel treatment for systemic lupus erythematosus.

BACKGROUND: Aconitum plants have been widely used in China for thousands of years. Recent evidences indicate that aconitine, the main active ingredient of Aconitum, has immunomodulatory properties that might be useful for treating autoimmune diseases, such as rheumatoid arthritis. In this study, we conducted a pilot study to explore the effect and mechanisms of aconitine on the treatment of systemic lupus erythematosus. METHODS: A pristane-induced murine model was used. The pristane-induced mice were treated with aconitine (25, 75 µg kg-1 d-1, po) for 9 weeks. Every three weeks, proteinuria was detected to monitor the kidney damage and blood was collected to measure serum levels of autoantibodies, besides the kidney pathological examination. The major B cell activating factor and major pro-inflammatory mediators, PGE2, IL-17a and IL-6, were also detected. RESULTS: We found that aconitine significantly improved the mouse health, decreased the elevated blood leukocyte counts, reduced the serum level of anti-double-stranded DNA (anti-dsDNA) antibody, greatly ameliorated renal histopathologic damage and reduced IgG deposit in glomerular. Furtherly, the levels of PGE2, IL-17a and IL-6, were found to have decreased in aconitine treated mice. CONCLUSION: We have demonstrated that aconitine can inhibit the progression of disease and ameliorate the pathologic lesion of systemic lupus erythematosus.

Muscadine Grape (Vitis rotundifolia) or Wine Phytochemicals Reduce Intestinal Inflammation in Mice with Dextran Sulfate Sodium-Induced Colitis.

The objective of this study was to determine the anti-inflammatory effects of phytochemical extracts from muscadine grapes or wine on dextran sulfate sodium (DSS)-induced colitis in mice and to investigate cellular mechanisms. Two groups of C57BL/6J mice were gavaged with muscadine grape phytochemicals (MGP) or muscadine wine phytochemicals (MWP), respectively, for 14 days. Acute colitis was induced by 3% DSS in drinking water for 7 days. An additional two groups of mice served as healthy and disease controls. Results indicated that MGP or MWP significantly prevented weight loss, reduced disease activity index, and preserved colonic length compared to the colitis group (p ≤ 0.05). MGP or MWP significantly decreased myeloperoxidase activity as well as the levels of IL-1ß, IL-6, and TNF-α in colon (p ≤ 0.05). MGP or MWP caused down-regulation of the NF-κB pathway by inhibiting the phosphorylation and degradation of IκB in a dose-dependent manner. These findings suggest that phytochemicals from muscadine grape or wine mitigate ulcerative colitis via attenuation of pro-inflammatory cytokine production and modulation of the NF-κB pathway.

Improvements in Metabolic Health with Consumption of Ellagic Acid and Subsequent Conversion into Urolithins: Evidence and Mechanisms.

Ellagic acid (EA) is a naturally occurring polyphenol found in some fruits and nuts, including berries, pomegranates, grapes, and walnuts. EA has been investigated extensively because of its antiproliferative action in some cancers, along with its anti-inflammatory effects. A growing body of evidence suggests that the intake of EA is effective in attenuating obesity and ameliorating obesity-mediated metabolic complications, such as insulin resistance, type 2 diabetes, nonalcoholic fatty liver disease, and atherosclerosis. In this review, we summarize how intake of EA regulates lipid metabolism in vitro and in vivo, and delineate the potential mechanisms of action of EA on obesity-mediated metabolic complications. We also discuss EA as an epigenetic effector, as well as a modulator of the gut microbiome, suggesting that EA may exert a broader spectrum of health benefits than has been demonstrated to date. Therefore, this review aims to suggest the potential metabolic benefits of consumption of EA-containing fruits and nuts against obesity-associated health conditions.

NMR-based metabolomics reveals urinary metabolome modifications in female Sprague-Dawley rats by cranberry procyanidins.

A (1)H NMR global metabolomics approach was used to investigate the urinary metabolome changes in female rats gavaged with partially purified cranberry procyanidins (PPCP) or partially purified apple procyanidins (PPAP). After collecting 24-h baseline urine, 24 female Sprague-Dawley rats were randomly separated into two groups and gavaged with PPCP or PPAP twice using a dose of 250 mg extracts per kilogram body weight. The 24-h urine samples were collected after the gavage. Urine samples were analyzed using (1)H NMR. Multivariate analyses showed that the urinary metabolome in rats was modified after administering PPCP or PPAP compared to baseline urine metabolic profiles. 2D (1)H-(13)C HSQC NMR was conducted to assist identification of discriminant metabolites. An increase of hippurate, lactate and succinate and a decrease of citrate and α-ketoglutarate were observed in rat urine after administering PPCP. Urinary levels of d-glucose, d-maltose, 3-(3'-hydroxyphenyl)-3-hydroxypropanoic acid, p-hydroxyphenylacetic acid, formate and phenol increased but citrate, α-ketoglutarate and creatinine decreased in rats after administering PPAP. Furthermore, the NMR analysis showed that the metabolome in the urine of rats administered with PPCP differed from those gavaged with PPAP. Compared to PPAP, PPCP caused an increase of urinary excretion of hippurate but a decrease of 3-(3'-hydroxyphenyl)-3-hydroxypropanoic acid, p-hydroxyphenylacetic acid and phenol. These metabolome changes caused by cranberry procyanidins may help to explain its reported health benefits and identify biomarkers of cranberry procyanidin intake.

Phytochemicals from Camellia nitidissima Chi inhibited the formation of advanced glycation end-products by scavenging methylglyoxal.

The objective of this study was to investigate the inhibitory effects of Camellia nitidissima Chi (CNC) on the advanced glycation end-product (AGE) formation. CNC was extracted with ethanol and further separated into dichloromethane, ethyl acetate, n-butanol, and water soluble fractions. Ethyl acetate fraction had the highest total phenolic and quercetin content compared with other fractions. Sixteen phenolic compounds were identified using HPLC Triple TOF MS/MS. Bovine serum albumin (BSA)-glucose assay showed that dichloromethane and ethyl acetate fraction inhibited AGE formation by 88.1% and 87.5% at 2.5mg/mL. BSA-methylglyoxal assay showed that ethyl acetate fraction inhibited 54.1% AGE formation while dichloromethane fraction inhibited 28.1%. Over 96.0% of methylglyoxal was scavenged by different fractions within 12h. Both mono- and di-methylglyoxal quercetin adducts were identified after incubating quercetin with methylglyoxal using HPLC-ESI-MS(n). The results in this study suggest that CNC extracts inhibited AGEs formation in part through scavenging methylglyoxal by phenolic compounds.

[Protective effects of three phenylallyl compounds from Guizhi decoction ox-LDL-induced oxidative stress injury of human brain microvascular endothelial cells].

The main objective of this research is to observe protective effects of three phenylallyl compounds(cinnamyl alcohol,cinnamaldehyde and cinnamic acid)from Guizhi decoction against ox-LDL-induced oxidative stress injury on human brain microvascular endothelial cells(HBMEC).In this study,the toxicity and optimal protective concentration of three phenylallyl compounds from Guizhi decoction were determined by MTT assay.The HBMEC were divided into control group(DMSO),model group(ox-LDL),tert-butylhydroquinone (t-BHQ) group,cinnamyl alcohol group, cinnamaldehyde group and cinnamic acid group.The model group were treated with ox-LDL (50 mg•L⁻¹)for 24 h,other groups were separately treated with t-BHQ, cinnamyl alcohol, cinnamaldehyde and cinnamic acid of 20 µmol•L⁻¹, and exposed to ox-LDL (50 mg•L⁻¹) for 24 h at the same time.The survival rate of HBMEC was detected by MTT assay,reactive oxygen species(ROS) production of injured cells were detected using laser scanning confocal microscope (LSCM),the content of SOD, MDA, eNOS and NO in HBMEC was determined by ELISA, and the expressions of Nrf2 mRNA were detected by quantitative Real-time PCR(qRT-PCR).The results shows that oxidative stress injury of HBMEC could be induced by ox-LDL, the three phenylallyl compounds from Guizhi decoction did not affect morphology and viability of normal HBMEC.Compared with model group, the three phenylallyl compounds from Guizhi decoction could improve the above oxidative stress status and up-regulate Nrf2 mRNA expressions in injured HBMEC(P<0.05, P<0.01) .These findings suggested that the three phenylallyl compounds from Guizhi decoction have certain protective effects against ox-LDL-induced oxidative stress injury on HBMEC(cinnamaldehyde> t-BHQ> cinnamic acid>cinnamyl alcohol),the protective mechanism maybe related to regulation of antioxidant enzymes gene expression in HBMEC by Nrf2.

Depolymerisation optimisation of cranberry procyanidins and transport of resultant oligomers on monolayers of human intestinal epithelial Caco-2 cells.

Procyanidins in cranberries are predominantly polymers (>85%). The objective of this study was to optimise the depolymerisation of polymers and to investigate the absorption of resultant oligomers on Caco-2 cell monolayers. Depolymerisation conditions were optimised using response surface methodology. Depolymerisation, with or without added epicatechin, yielded 644 µg and 202 µg of oligomers (monomer through tetramers) per mg of partially purified polymers (PP), respectively. Oligomers (yielded from both methods) were transported through Caco-2 cell monolayer despite absorption rates being low. With the aid of response surface methodology, the optimum depolymerisation conditions were determined to be 60°C, 0.1M HCl in methanol and 3h without added epicatechin. The predicted maximum yield was 364 µg oligomers per mg of PP. The optimum depolymerisation condition with added epicatechin shared the same temperature, acid concentration and reaction time, in addition to an epicatechin/PP mass ratio of 2.19. Its predicted maximum oligomer yield was 1,089 µg/mg. The predicted yields were verified by experimental data.

Microbial catabolism of procyanidins by human gut microbiota.

SCOPE: A major portion of ingested procyanidins is degraded by human microbiota in the colon into various phenolic compounds. These microbial metabolites are thought to contribute to the health benefits of procyanidins in vivo. The objective of this study was to identify and quantify the microbial metabolites of procyanidins after anaerobic fermentation with human microbiota. METHODS AND RESULTS: (-)-Epicatechin, (+)-catechin, procyanidin B2, procyanidin A2, partially purified apple and cranberry procyanidins were incubated with human microbiota at a concentration equivalent to 0.5 mM epicatechin. GC-MS analysis showed that common metabolites of all six substrates were benzoic acid, 2-phenylacetic acid, 3-phenylpropionic acid, 2-(3'-hydroxyphenyl)acetic acid, 2-(4'-hydroxyphenyl)acetic acid, 3-(3'-hydroxyphenyl)propionic acid, and hydroxyphenylvaleric acid. 5-(3',4'-Dihydroxyphenyl)-γ-valerolactones and 5-(3'-hydroxyphenyl)-γ-valerolactones were identified as the microbial metabolites of epicatechin, catechin, procyanidin B2, and apple procyanidins but not from the procyanidin A2 or cranberry procyanidin ferments. 2-(3',4'-Dihydroxyphenyl)acetic acid was only found in the fermented broth of procyanidin B2, A2, apple, and cranberry procyanidins. The mass recoveries of microbial metabolites range from 20.0 to 56.9% for the six substrates after 24 h of fermentation. CONCLUSION: Procyanidins, both B-type and A-type can be degraded by human gut microbiota. The microbial metabolites may contribute to the bioactivities of procyanidins.

Ocular inflammation and endoplasmic reticulum stress are attenuated by supplementation with grape polyphenols in human retinal pigmented epithelium cells and in C57BL/6 mice.

Inflammation and endoplasmic reticulum (ER) stress are common denominators for vision-threatening diseases such as diabetic retinopathy and age-related macular degeneration. Based on our previous study, supplementation with muscadine grape polyphenols (MGPs) alleviated systemic insulin resistance and proinflammatory responses. In this study, we hypothesized that MGPs would also be effective in attenuating ocular inflammation and ER stress. We tested this hypothesis using the human retinal pigmented epithelium (ARPE-19) cells and C57BL/6 mice. In ARPE-19 cells, tumor necrosis factor-α-induced proinflammatory gene expression of interleukin (IL)-1ß, IL-6, and monocyte chemotactic protein-1 was decreased by 35.0%, 68.8%, and 62.5%, respectively, with MGP pretreatment, which was primarily due to the diminished mitogen-activated protein kinase activation and subsequent reduction of nuclear factor κ-B activation. Consistently, acute ocular inflammation and leukocyte infiltration were almost completely dampened (>95%) by MGP supplementation (100-200 mg/kg body weight) in C57BL/6 mice. Moreover, MGPs reduced inflammation-mediated loss of tight junctions and retinal permeability. To further investigate the protective roles of MGPs against ER stress, ARPE-19 cells were stimulated with thapsigargin. Pretreatment with MGPs significantly decreased the following: 1) ER stress-mediated vascular endothelial growth factor secretion (3.47 ± 0.06 vs. 1.58 ± 0.02 µg/L, P < 0.0001), 2) unfolded protein response, and 3) early apoptotic cell death (64.4 ± 6.85 vs. 33.7 ± 4.32%, P = 0.0003). Collectively, we have demonstrated that MGP is effective in attenuating ocular inflammation and ER stress. Our work also suggests that MGP may provide a novel dietary strategy to prevent vision-threatening retinal diseases.