Concentrated red grape juice exerts antioxidant, hypolipidemic, and antiinflammatory effects in both hemodialysis patients and healthy subjects

The impacts of dietary antioxidants on cardiovascular events in hemodialysis patients: An update on the cellular and molecular mechanisms

Cardiovascular-related complications (CVCs) are the primary cause of death in patients undergoing hemodialysis (HD), accounting for greater than half of all deaths. Beyond traditional risk factors, chronic inflammation, extreme oxidative stress (OS), and endothelial dysfunction emerge as major contributors to accelerated CVCs in HD patients. Ample evidence shows that HD patients are constantly exposed to excessive OS, due to uremic toxins and pro-oxidant molecules that overwhelm the defense antioxidant mechanisms. The present study highlights the efficiency of natural antioxidant supplementation in managing HD-induced inflammation, OS, and consequently CVCs. Moreover, it discusses the underlying molecular mechanisms by which these antioxidants can decrease mitochondrial and endothelial dysfunction and ameliorate CVCs in HD patients. Given the complex nature of OS and its molecular pathways, the utilization of specific antioxidants as a polypharmacotherapy may be necessary for targeting each dysregulated signaling pathway and reducing the burden of CVCs.

Untargeted urine metabolomics suggests that ascorbic acid may serve as a promising biomarker for reduced feed intake in rabbits

Feed restriction is a common nutritional practice in rabbit farming; however, decreased feed intake can also signal potential digestive disorders at an early stage. This study endeavors to investigate the impact of feed restriction on selected productive traits and the urinary metabolome of juvenile rabbits across diverse genetic backgrounds. Our objective is to identify potential biomarkers capable of detecting periods of fasting. A total of 48 growing rabbits were used from two genetic types: Prat line (selected for litter size at weaning, n = 24) and Caldes line (selected for post-weaning growth rate, n = 24). At 60 days of age, a digestibility trial was carried out. Changes in productive traits (through bioelectrical impedance analysis, live weight control, average daily gain, energy, and protein retention) were evaluated when the animals were fed ad libitum from 60 to 64 days of age and when the same animals were subjected to feed restriction (50% of maintenance energy requirements) from 70 to 74 days of age, in a split-plot trial. In addition, untargeted urine metabolomics analysis was performed at both periods (ad libitum vs. restricted). Although some differences between genetic lines were observed in the animals' performance traits (average daily gain and retention of energy and protein), no differences in the urine metabolome were found between genetic types. However, feed restriction caused notable changes in the metabolome. When the animals were subjected to feed restriction, they had higher levels of ascorbic acid (P = 0.001) and p-cresol sulphate (P = 0.058) and lower levels of pyrocatechol sulphate/hydroquinone sulphate (P < 0.001), resorcinol sulphate (P = 0.002), enterolactone sulphate (P < 0.001), enterolactone (P < 0.001), kynurenic acid (P = 0.0002), proline betaine (P < 0.001), pipecolic acid betaine (P < 0.001), xanthurenic acid (P < 0.001) and quinaldic acid (P < 0.001) than the same animals when they were fed ad libitum. This study proposes urine ascorbic acid as potential biomarker for fasting events in rabbits. As urine ascorbic acid is the sole metabolite that significantly increases in the restricted group, it offers promising indicator for early detection and targeted management of digestive disorders in rabbits.

Evaluating the Impact of Pre-Fermentative and Post-Fermentative Vinification Technologies on Bioactive Compounds and Antioxidant Activity of Teran Red Wine By-Products

This study aimed to evaluate bioactive properties of Teran red wine by-products (grape skins, seeds, and wine lees) from six vinification treatments, including a control (7-day standard maceration). Pre-fermentative cryomaceration (8 °C; 48 h) and hot maceration (50 °C; 48 h), followed by the 13-day (CS15; C15; H15) and 28-day (C30; H30) period, considering fermentation/maceration and extended post-fermentative maceration, were conducted. In CS15, the saignée procedure was applied before fermentation/maceration. After maceration, the separation of by-products was performed, followed by lyophilization and solid-liquid extraction. Then, individual phenols were analyzed using high-performance liquid chromatography (HPLC), and total phenolic content (TPC) and antioxidant activity (FRAP) were analyzed using UV/Vis spectrophotometry. The results showed grape skins and wine lees in all treatments had significantly increased TPC and FRAP values compared to the control. The highest concentration of total phenols (HPLC) in grape skins was found in CS15, at 978.54 mg/100 g DW. In wine lees, the highest concentration of total phenols was detected in the 30-day maceration treatments, at 582.04 mg/100 g DW in C30, and 595.83 mg/100 g DW in H30, despite the pre-fermentative procedure. In grape seeds, the highest concentration of total phenols was found in the control (K7), at 432.42 mg/100 g DW. Pre-fermentative heating together with extended 30-day maceration (H30) strongly reduced the total levels of phenols (HPLC and TPC) in grape seed samples. The findings implied an evident impact of pre- and post-fermentative technologies on phenols and antioxidant activity in wine by-products of cv. Teran (Vitis vinifera L.).

Liraglutide and resveratrol alleviated cyclosporin A induced nephrotoxicity in rats through improving antioxidant status, apoptosis and pro-inflammatory markers

The recent study delves into the role of both liraglutide and/or resveratrol on the nephropathic affection in rats treated with cyclosporine A (CsA). Rats were intoxicated with CsA (25 mg/kg) orally for 21 days and were supplemented with liraglutide (30 μg/kg) s/c daily and 20 mg/kg of resveratrol (20 mg/kg) orally. At the end of the experiment, serum samples and renal tissues were collected to determine renal damage markers, apoptotic markers, proinflammatory markers, and antioxidant status markers. Kidney function tests and antioxidant activity notably improved in the treated rats (CsA + Lir/CsA + Res/CsA + Lir + Res). Moreover, both Lir and/or Res enhanced Bcl-2 levels while down-regulating the Bax levels in rats treated with CsA. Interestingly, the immune-staining for tumor necrosis factor (TNF-α) was tested negative and mild positive in renal tissue of rats given Lir and/or Res while being treated with Cs A which indicated their anti-inflammatory effect that reduced the renal damage. The findings of this investigation revealed the ameliorative anti-inflammatory in addition to the antioxidant role of both liraglutide and resveratrol against the kidney damage caused due to CsA administration.

Biomarkers for ideal protein: rabbit diet metabolomics varying key amino acids

With the main aim of identifying biomarkers that contribute to defining the concept of ideal protein in growing rabbits under the most diverse conditions possible this work describes two different experiments. Experiment 1: 24 growing rabbits are included at 56 days of age. The rabbits are fed ad libitum one of the two experimental diets only differing in lysine levels. Experiment 2: 53 growing rabbits are included at 46 days of age, under a fasting and eating one of the five experimental diets, with identical chemical composition except for the three typically limiting amino acids (being fed commercial diets ad libitum in both experiments). Blood samples are taken for targeted and untargeted metabolomics analysis. Here we show that the metabolic phenotype undergoes alterations when animals experience a rapid dietary shift in the amino acid levels. While some of the differential metabolites can be attributed directly to changes in specific amino acids, creatinine, urea, hydroxypropionic acid and hydroxyoctadecadienoic acid are suggested as a biomarker of amino acid imbalances in growing rabbits' diets, since its changes are not attributable to a single amino acid. The fluctuations in their levels suggest intricate amino acid interactions. Consequently, we propose these metabolites as promising biomarkers for further research into the concept of the ideal protein using rabbit as a model.

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

Proposed mechanisms of action of herbal drugs and their biologically active constituents in the treatment of coughs: an overview

Various medicinal plants find their use in cough treatment, based on traditions and long-term experience. Pharmacological principles of their action, however, are much less known. Herbal drugs usually contain a mixture of potentially active compounds, which can manifest diverse effects. Expectorant or antitussive effects, which can be accompanied by others, such as anti-inflammatory or antibacterial, are probably the most important in the treatment of coughs. The aim of this review is to summarize the current state of knowledge of the effects of medicinal plants or their constituents on cough, based on reliable pharmacological studies. First, a comprehensive description of each effect is provided in order to explain the possible mechanism of action in detail. Next, the results related to individual plants and substances are summarized and critically discussed based on pharmacological in vivo and in vitro investigation.

Antioxidant Capacity and NF-kB-Mediated Anti-Inflammatory Activity of Six Red Uruguayan Grape Pomaces

Grape pomaces have a wide and diverse antioxidant phenolics composition. Six Uruguayan red grape pomaces were evaluated in their phenolics composition, antioxidant capacity, and anti-inflammatory properties. Not only radical scavenging methods as DPPH^· and ABTS^·+ were employed but also ORAC and FRAP analyses were applied to assess the antioxidant potency of the extracts. The antioxidant reactivity of all extracts against hydroxyl radicals was assessed with ESR. The phenol profile of the most bioactive extract was analyzed by HPLC-MS, and a set of 57 structures were determined. To investigate the potential anti-inflammatory activity of the extracts, Nuclear Factor kappa-B (NF-κB) modulation was evaluated in the human colon cancer reporter cell line (HT-29-NF-κB-hrGFP). Our results suggest that Tannat grapes pomaces have higher phenolic content and antioxidant capacity compared to Cabernet Franc. These extracts inhibited TNF-alpha mediated NF-κB activation and IL-8 production when added to reporter cells. A molecular docking study was carried out to rationalize the experimental results allowing us to propose the proactive interaction between the NF-κB, the grape extracts phenols, and their putative anti-inflammatory bioactivity. The present findings show that red grape pomace constitutes a sustainable source of phenolic compounds, which may be valuable for pharmaceutical, cosmetic, and food industry applications.

Anthocyanins-rich interventions on oxidative stress, inflammation and lipid profile in patients undergoing hemodialysis: meta-analysis and meta-regression

The aim of this systematic review and meta-analysis was to evaluate the effects of anthocyanins-interventions on oxidative stress, inflammation, and lipid profile in patients undergoing hemodialysis. This systematic review and meta-analysis were registered on the International Prospective Register of Systematic Reviews (PROSPERO CRD42020209742). The primary outcome was anthocyanins-rich intervention on OS parameters and secondary outcome was anthocyanins-rich intervention on inflammation and dyslipidemia. RevMan 5.4 software was used to analyze the effect size of anthocyanins-rich intervention on OS, inflammation and dyslipidemia. Meta-analysis effect size calculations incorporated random-effects model for both outcomes 1 and 2. Eight studies were included in the systematic review (trials enrolling 715 patients; 165 men and 195 women; age range between 30 and 79 years). Anthocyanin intervention in patients undergoing hemodialysis decrease the oxidant parameters (std. mean: -2.64, 95% CI: [-3.77, -1.50], P ≤ 0.0001, I² = 97%). Specially by reduction of malondialdehyde products in favor of anthocyanins-rich intervention (std. mean: -14.58 µmol.L, 95% CI: [-26.20, -2.96], P ≤ 0.0001, I² = 99%) and myeloperoxidase (std. mean: -1.28 ηg.mL, 95% CI: [-2.11, -0.45], P = 0.003, I² = 77%) against placebo group. Decrease inflammatory parameters (std. mean: -0.57, 95% CI: [-0.98, -0.16], P = 0.007, I² = 79%), increase HDL cholesterol levels (std. mean: 0.58 mg.dL, 95% CI: [0.23, 0.94], P = 0.001, I² = 12%) against placebo group. Anthocyanins-rich intervention seems to reduce oxidative stress, inflammatory parameters and improve lipid profile by increasing HDL cholesterol levels in patients with chronic kidney disease undergoing hemodialysis.

Effect of Dietary Phenolic Compounds on Incidence of Type 2 Diabetes in the "Seguimiento Universidad de Navarra" (SUN) Cohort

The global incidence of type 2 diabetes (T2D) has been steadily increasing in recent decades. The Mediterranean dietary pattern has shown a preventive effect on the risk of T2D. Evaluating the association between bioactive compounds such as phenolic compounds (PC) in a Mediterranean cohort could help to better understand the mechanisms implicated in this protection. We evaluated the association between dietary intake of PC and the risk of T2D in a relatively young cohort of 17,821 Spanish participants initially free of T2D, through the University of Navarra Follow-up Project ("Seguimiento Universidad de Navarra" or SUN cohort) after 10 years of median follow-up using time-dependent Cox models. Intake of PC was estimated at baseline and repeatedly at 10-year follow-up using a 136-item validated food frequency and the Phenol-Explorer database. The incidence of T2D was identified by a biennial follow-up, and only medically confirmed cases were included. During 224,751 person-years of follow-up, 186 cases of T2D were confirmed. A suboptimal intake of stilbenes was independently associated with a higher risk of T2D in subjects over 50 years (HR: 1.75, 95% CI: 1.06-2.90, p value < 0.05) after adjusting for potential confounders. Our results suggest that a moderate-high intake of stilbenes can decrease the risk of developing T2D in subjects over 50 years in our cohort.

Serum from Adolescents with High Polyphenol Intake Exhibits Improved Lipid Profile and Prevents Lipid Accumulation in HepG2 Human Liver Cells

The traditional Mediterranean diet (MD) is characterized by a high phenolic-rich food intake, including in particular vegetables and fruits, but also legumes, whole grain cereals, nuts, and extra virgin olive oil. Evidence for beneficial effects of polyphenols in humans depends on the amount consumed and on their bioavailability. Here, we evaluated the association between the estimated polyphenol intake by fruits and vegetables food source and serum biochemical parameters in healthy adolescents, recruited into the DIMENU research project. Categorizing adolescents into three groups according to their estimated total polyphenol intake, we found that adolescents who declared high consumption of polyphenols had a higher adherence to the MD and had a better serum lipid profile than adolescents consuming low amounts of polyphenols. Moreover, using human HepG2 liver cells treated with oleic acid as an in vitro model for studying lipid accumulation, we showed that intracellular lipid accumulation is alleviated by serum from adolescents consuming a polyphenol-rich diet following MD recommendations. Our data underline the importance of promoting adherence to the typical MD foods as a superior strategy to prevent metabolic and chronic diseases and to ensure a better quality of life among adolescents.

Chardonnay Marc as a New Model for Upcycled Co-products in the Food Industry: Concentration of Diverse Natural Products Chemistry for Consumer Health and Sensory Benefits

Research continues to provide compelling insights into potential health benefits associated with diets rich in plant-based natural products (PBNPs). Coupled with evidence from dietary intervention trials, dietary recommendations increasingly include higher intakes of PBNPs. In addition to health benefits, PBNPs can drive flavor and sensory perceptions in foods and beverages. Chardonnay marc (pomace) is a byproduct of winemaking obtained after fruit pressing that has not undergone fermentation. Recent research has revealed that PBNP diversity within Chardonnay marc has potential relevance to human health and desirable sensory attributes in food and beverage products. This review explores the potential of Chardonnay marc as a valuable new PBNP ingredient in the food system by combining health, sensory, and environmental sustainability benefits that serves as a model for development of future ingredients within a sustainable circular bioeconomy. This includes a discussion on the potential role of computational methods, including artificial intelligence (AI), in accelerating research and development required to discover and commercialize this new source of PBNPs.

Polyphenols and atherosclerosis: A critical review of clinical effects on LDL oxidation

Atherosclerosis is a major etiology of cardiovascular disease that causes considerable mortality. Oxidized low-density lipoprotein (oxLDL) is a fundamental attributor to atherosclerosis. Therefore, there seems to be an essential place for antioxidant therapy besides the current treatment protocols for coronary heart disease. Polyphenols are a class of compounds with substantial antioxidant properties that have shown the ability to reduce LDL oxidation in preclinical studies. However, clinical evidence has not been as conclusive although offering many promising signs. This review aims to examine the trials that have evaluated how dietary intake of polyphenols in different forms might influence the oxidation of LDL. Lowering the circulating cholesterol, incorporation into LDL particles, and enhancing systemic antioxidant activity are among the main mechanisms of action for polyphenols for lowering oxLDL. On the other hand, the population under study significantly affects the impact on oxLDL, as the type of the supplement and phenolic content. To conclude, although the polyphenols might decrease inflammation and enhance endothelial function via lowering oxLDL, there are still many gaps in our knowledge that need to be filled with further high-quality studies.

Profiling the Volatile and Non-Volatile Compounds along with the Antioxidant Properties of Malted Barley

In this work, the stability of antioxidant compounds in malting barley seeds before and after the production of the final products is reported. In this reflection, the findings revealed that the process of fermentation had a significant impact on antioxidant activity. In vitro, antioxidant capacities were evaluated using DPPH free radical scavenging assay. The results obtained from the spectrophotometric analysis showed that the lowest inhibition value was observed in the samples that were obtained by the classical fermentation process (ABC) and the samples of non-alcoholic beer obtained by the thermal process (NABT), with free radical inhibition capacity values of 8.50% and 5.50%, respectively. The samples of hopped wort (HW) and malted barley seeds extract (BSE) showed very high antioxidant activity with free radical inhibition capacity of 14% and 12.60%, respectively. The obtained extracts were analyzed by gas chromatography and high-performance liquid chromatography, both combined with mass spectrometry detection (GC–MS, HPLC–MS). GC–MS analysis of the SPME extraction showed the presence of 29 compounds with isopentyl alcohol in major concentration (18.19%) in the alcoholic beer; on the other hand, the HPLC–DAD–ESI/MS analysis of the ethyl acetate extract showed the presence of 13 phenolic compounds. Interestingly, the degradation of 3-Hydroxyphloretin 2′-O-glucoside in the final products of the non-alcoholic beers was found. Finally, the FTIR analysis was also employed in order to detect the type of efficient groups present in the extracts.

The effect of black rot on grape berry composition

Guignardia bidwellii, indigenous to North America, is a significant pathogen of grapes long known in Hungary, infecting only the growing green parts of the vine (leaves, petioles, shoots, and bunches). In the absence of adequate plant protection and extreme weather conditions such as a predominantly humid, warm year, black rot of grapes can be expected. The pathogen can cause high yield losses due to grape rot and reduce wine quality if the infection is severe.

The evolution of certain biogenic amine compounds were investigated under the influence of grape black rot. The results obtained showed that they were present in low concentrations from an oenological point of view. Polyphenol composition was consistent with the literature, blackening affected mainly the concentration of catechin. Black rot fungus does not produce β-glucosidase enzyme. In terms of resveratrol content, black rot has no particular effect. However, like Botrytis cinerea, it produces glycerol and, proportionally, gluconic acid in lower concentrations.

It can be concluded that black rot of grapes does not cause health problems when introduced into wine processing.

Inflammation and Oxidative Stress in Chronic Kidney Disease and Dialysis Patients

Significance: Chronic kidney disease (CKD) can be regarded as a burden of lifestyle disease that shares common underpinning features and risk factors with the aging process; it is a complex constituted by several adverse components, including chronic inflammation, oxidative stress, early vascular aging, and cellular senescence. Recent Advances: A systemic approach to tackle CKD, based on mitigating the associated inflammatory, cell stress, and damage processes, has the potential to attenuate the effects of CKD, but it also preempts the development and progression of associated morbidities. In effect, this will enhance health span and compress the period of morbidity. Pharmacological, nutritional, and potentially lifestyle-based interventions are promising therapeutic avenues to achieve such a goal. Critical Issues: In the present review, currents concepts of inflammation and oxidative damage as key patho-mechanisms in CKD are addressed. In particular, potential beneficial but also adverse effects of different systemic interventions in patients with CKD are discussed. Future Directions: Senotherapeutics, the nuclear factor erythroid 2-related factor 2-kelch-like ECH-associated protein 1 (NRF2-KEAP1) signaling pathway, the endocrine klotho axis, inhibitors of the sodium-glucose cotransporter 2 (SGLT2), and live bio-therapeutics have the potential to reduce the burden of CKD and improve quality of life, as well as morbidity and mortality, in this fragile high-risk patient group. Antioxid. Redox Signal. 35, 1426-1448.

Anti-diabetic effect of Stachytarpheta jamaicensis on low dose streptozotocin-induced diabetic rats fed on a high-fat diet

Introduction

This study evaluates the anti-diabetic effect of ethanol extract of Stachytarpheta jamaicensis leaf on streptozotocin (STZ) - induced diabetic rats fed on high-fat diet (HFD).

Methods

Sets of male albino rats of the Wistar strain weighing between 180 and 250 g were exposed to high fat diet (margarine and oil from vegetable sources in a ratio of 2:1 w/v) for 3 weeks. Then the animals were fasted overnight; hyperglycemic state was induced using reduced dose of streptozotocin (35 mg/kg) and animals were randomly divided into five groups (n = 7); group A received the HFD + STZ (35 mg/kg i.p.); group B received HFD + STZ + gliberclamide (10 mg/kg; i.p); groups C, D and E were administered the HFD + streptozotocin with different doses of the ethanol extract (30, 35 and 100 mg/kg p.o., respectively).

Results

Results showed significant (p < 0.05) decrease in blood glucose concentration of the rats treated with different doses of S. jamaicensis extract and those treated with gliberclamide compared to the untreated diabetic rats (negative control). Significant (p < 0.05) reductions in activities of serum AST, ALP, total protein and bilirubin were noticed in the groups in contrast to the control. Levels of urea, creatinine, potassium and chloride were considerably (p < 0.05) low while sodium and bicarbonate levels were high in the groups except the control. Lipid profile revealed significant (p < 0.05) reduction in total cholesterol, triacylglycerol, LDL, VLDL while HDL levels were high in the groups compared to the control. The extract significantly (p < 0.05) ameliorated weight loss. Histopathology of the liver, kidney and pancreas showed ameliorative effect of the extract against the deleterious changes occasioned by the HFD and STZ induced diabetic state.

Conclusion

These findings have provided scientific basis for the use of S. jamaicensis in the treatment of diabetes mellitus in ethnomedicinal practices in Nigeria.

Anti-diuretic and anti-glycemic properties of Jatropha gossypiifolia L. leave extract on wistar rats

Background

Jatropha gossypiifolia L. is a widespread plant in tropical and sub-tropical countries used in traditional medicine. This study investigated the anti-diuretic and anti-hyperglycemia activities of J. gossypiifolia leave extract on streptozotocin-induced diabetic rats.

Methods

The leaves was shade dried, pulverized and prepared into extract. 30, 50 and 100 mg/kg of the leaves extracts of J. gossypiifolia was subject to diuretics and hyperglycemic properties using established protocol of diuretic and diabetes test on the rat bladders emptied via mild compression in the pelvic region and gently pulling of their tails. 0.5 ml/kg normal saline, reference drug and the tested were administered with a single dose of the various drugs, and Streptozotocin (STZ) was freshly prepared in 0.1 M citrate buffer with pH 4.5 prior to induction, animals were fasted 24 h and single dose of 45 mg STZ per kg body weight was administered intraperitoneally. Urine and blood samples were isolated from rats and centrifuged for the determination of renal function test. Diuretic and antidiabetic indexes where evaluated using adopted method.

Results

This study showed that, graded doses of the extract significantly increased diuretic effect, specifically at 100 mg/kg increased diuretic index at 4.29 and urine volume 5.06 and 10 mg/kg Hydrochlorothiazide with 6.23 ml when compared untreated group (1.18 ml) (p < 0.0001). Also, it regulated renal function in homeostatic state. Graded doses at (30, 50 and 100 mg/kg) of the extract significantly reduced streptozotocine induced increased blood glucose level at day 14 (84.00, 60.67 and 42.00 IU/mL) when compared with 20 mg/kg glibenclamide and diabetics control (81.67 and 463.00 IU/mL) (p > 0.05). Also, the extract maintained a normal body mass indexes, biochemical and anatomical structure.

Conclusion

The effect associated with J. gossypiifolia potentiated its anti-diuretic and anti-hyperglycemic properties as early stated in the ethnomedicinal reports.

Understanding the Functional Activity of Polyphenols Using Omics-Based Approaches

Plant polyphenols are the main category of natural active substances, and are distributed widely in vegetables, fruits, and plant-based processed foods. Polyphenols have a beneficial performance in preventing diseases and maintaining body health. However, its action mechanism has not been well understood. Foodomics is a novel method to sequence and widely used in nutrition, combining genomics, proteomics, transcriptomics, microbiome, and metabolomics. Based on multi-omics technologies, foodomics provides abundant data to study functional activities of polyphenols. In this paper, physiological functions of various polyphenols based on foodomics and microbiome was discussed, especially the anti-inflammatory and anti-tumor activities and gut microbe regulation. In conclusion, omics (including microbiomics) is a useful approach to explore the bioactive activities of polyphenols in the nutrition and health of human and animals.

Recent Molecular Mechanisms and Beneficial Effects of Phytochemicals and Plant-Based Whole Foods in Reducing LDL-C and Preventing Cardiovascular Disease

Abnormal lipid metabolism leads to the development of hyperlipidemia, a common cause of multiple chronic disorders, including cardiovascular disease (CVD), obesity, diabetes, and cerebrovascular disease. Low-density lipoprotein cholesterol (LDL-C) currently remains the primary target for treatment of hyperlipidemia. Despite the advancement of treatment and prevention of hyperlipidemia, medications used to manage hyperlipidemia are limited to allopathic drugs, which present certain limitations and adverse effects. Increasing evidence indicates that utilization of phytochemicals and plant-based whole foods is an alternative and promising strategy to prevent hyperlipidemia and CVD. The current review focuses on phytochemicals and their pharmacological mode of actions for the regulation of LDL-C and prevention of CVD. The important molecular mechanisms illustrated in detail in this review include elevation of reverse cholesterol transport, inhibition of intestinal cholesterol absorption, acceleration of cholesterol excretion in the liver, and reduction of cholesterol synthesis. Moreover, the beneficial effects of plant-based whole foods, such as fresh fruits, vegetables, dried nuts, flax seeds, whole grains, peas, beans, vegan diets, and dietary fibers in LDL-C reduction and cardiovascular health are summarized. This review concludes that phytochemicals and plant-based whole foods can reduce LDL-C levels and lower the risk for CVD.

The effect of grapes/grape products on glycemic response: A systematic review and meta-analysis of randomized controlled trials

The aim of this study was to perform a systematic review and meta-analysis of randomized clinical trials (RCTs) to examine the effect of grapes/grape products supplementation on glycemic indices in adults. Our systematic search to find relevant RCTs was performed up to February 2020 using PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar. Based on the heterogeneity between included studies, a random effects or a fixed model was applied in the meta-analysis, and results were expressed as weighted mean differences (WMD) with 95% confidence intervals (CI). Twenty-nine clinical trials (1,297 participants) fulfilled the eligibility criteria of the present meta-analysis. Overall, the grapes/grape products supplementation significantly reduced homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: -0.54, 95% CI: -0.91, -0.17, p = . 004) but did not affect fasting insulin levels (WMD: -0.90 μIU/ml, 95% CI: -1.04, 2.84, p = .362) and hemoglobin A1C (Hb1Ac) percentage (WMD: 0.00%, 95% CI: -0.10, 0.11, p = . 916) in the main analyses. In addition, changes to fasting blood glucose (FBG) levels were in favor of the control group (WMD: 1.19 mg/dl, 95% CI: 0.05, 2.34, p = .041). We found that giving grapes/grape products to adults might have beneficial effects on the HOMA-IR. Further, large-scale RCTs with longer duration are required to confirm these results.

Effects of Aleurone Supplementation on Glucose-Insulin Metabolism and Gut Microbiome in Untrained Healthy Horses

Aleurone, a layer of the bran fraction, is deemed to be responsible for the positive health effects associated with the consumption of whole-grain products. Studies on rodents, pigs, and humans report beneficial effects of aleurone in five main areas: the reduction of oxidative stress, immunomodulatory effects, modulation of energy management, digestive health, and the storage of vitamins and minerals. Our study is the first aleurone supplementation study performed in horses. The aim of this study was to investigate the effect of an increase in the dose levels of aleurone on the postprandial glucose-insulin metabolism and the gut microbiome in untrained healthy horses. Seven adult Standardbred horses were supplemented with four different dose levels of aleurone (50, 100, 200, and 400 g/day for 1 week) by using a Latin square model with a 1-week wash out in between doses. On day 7 of each supplementation week, postprandial blood glucose-insulin was measured and fecal samples were collected. 16S ribosomal RNA (rRNA) gene sequencing was performed and QIIME2 software was used for microbiome analysis. Microbial community function was assessed by using the predictive metagenome analysis tool Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and using the Metacyc database of metabolic pathways. The relative abundancies of a pathway were analyzed by using analysis of composition of microbiomes (ANCOM) in R. There was a significant dose-dependent increase in the postprandial time to peak of glucose (p = 0.030), a significant delay in the time to peak of insulin (p = 0.025), and a significant decrease in both the insulin peak level (p = 0.049) and insulin area under the curve (AUC) (p = 0.019) with increasing dose levels of aleurone, with a consideration of 200 g being the lowest significant dose. Alpha diversity and beta diversity of the fecal microbiome showed no significant changes. Aleurone significantly decreased the relative abundance of the genera Roseburia, Shuttleworthia, Anaerostipes, Faecalibacter, and Succinovibrionaceae. The most pronounced changes in the relative abundance at phyla level were seen in Firmicutes and Verrucomicrobia (downregulation) and Bacteroidetes and Spirochaetes (upregulation). The PICRUSt analysis shows that aleurone induces a downregulation of the degradation of L-glutamate and taurine and an upregulation of the three consecutive pathways of the phospholipid membrane synthesis of the Archaea domain. The results of this study suggest a multimodal effect of aleurone on glucose-insulin metabolism, which is most likely to be caused by its effect on feed texture and subsequent digestive processing; and a synergistic effect of individual aleurone components on the glucose-insulin metabolism and microbiome composition and function.

The effect of grape products containing polyphenols on oxidative stress: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The literature showed that Grape Products Containing Polyphenols (GPCP) had anti-oxidant activity. However, the effects of GPCP on different biomarkers of oxidative stress are still controversial. In this regard, this systematic review and meta-analysis aimed to evaluate the effect of Grape Products Containing Polyphenols (GPCP) intake on oxidative stress markers.

METHODS

PubMed, Scopus, Web of Science, and Google Scholar data bases were searched up to August 20, 2020. A random-effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were applied for data analysis. Meta-analysis was conducted over 17 eligible RCTs with a total of 633 participants. The study registration number is CRD42019116696.

RESULTS

A significant increase was observed in Total Antioxidant Capacity (TAC) (weighted mean difference (WMD) = 1.524 mmol/L, 95% confidence interval (CI): 0.83, 2.21). Intake of GPCP enhanced Superoxide Dismutase (SOD) (WMD = 0.450 mmol/L, 95% CI: 0.23, 0.66), TAC (WMD = 2.829 mmol/L, 95% CI: 0.13, 5.52), and Oxygen Radical Absorbance Capacity (ORAC) (WMD = 0.524 μmol/L, 95% CI: 0.42, 0.62) among healthy participants. Higher GPCP doses increased SOD (WMD = 0.539 U/mgHb, 95% CI: 0.24, 0.82) and ORAC (WMD = 0.377 μmol/L, 95% CI: 0.08, 0.67), whereas longer intervention periods enhanced ORAC (WMD = 0.543 μmol/L, 95% CI: 0.43, 0.64).

CONCLUSION

GPCP intake may partly improve status of oxidative stress, but further well-designed trials are required to confirm these results.

Dietary intakes of total polyphenol and its subclasses in association with the incidence of chronic kidney diseases: a prospective population-based cohort study

Background

As chronic kidney disease (CKD) is amongst the current global health challenges, this study is aiming to evaluate the long-term intake of total polyphenol and its subclasses in association with CKD incidence.

Methods

For the purpose of this study, a sample of 3021 Iranian adults (47 % men, aged 20–79 years) with no CKD diagnosis at baseline, were selected from the Tehran Lipid and Glucose Study population. The total intake of polyphenol and its major subclasses were assessed by a validated food frequency questionnaire and categorized as flavonoids, phenolic acids, stilbenes, and lignans. Although the morphological abnormalities of the kidneys or 3-month persistent urinalysis can distinctively define CKD, the glomerular filtration rate (eGFR) reduction is accepted as a more precise index of renal function. Therefore, eGFR < 60 mL/min/1.73m² was the exclusive index of CKD diagnosis in the current study. The eGFR was calculated by the Modification of Diet in Renal Disease Study equation. Cox-regression analysis was used to assess the hazard ratio and 95 % confidence intervals of CKD in quartiles of the total polyphenols.

Results

In this study, 355 CKD cases over 11,058.464 person-years was reported. The median (IQR) age of participants was 36 years (27–46) at baseline. Moderate intake of lignans (≤ 6.8 mg) was negatively associated with the incidence of CKD in the adjusted model. No significant associations were detected between higher amounts of lignin and total polyphenols (HR: 0.97, 95 % CI 0.67–1.40) and CKD incidence.

Conclusions

Based on the current findings, moderate intake of lignin possess CKD-protective properties by approximately 32 %. No independent associations were observed between higher amounts of lignins and CKD incidence.

The effect of black seed raisin on some cardiovascular risk factors, serum malondialdehyde, and total antioxidant capacity in hyperlipidemic patients: a randomized controlled trials

BACKGROUND

The lipid-lowering properties and antioxidants of the raisins may reduce the risk factors of cardiovascular diseases. This study aimed to investigate the effect of black seeded raisin consumption on blood pressure (BP), lipid profile, high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), and serum total antioxidant capacity (TAC) in hyperlipidemic patients.

METHODS

Thirty-eight hyperlipidemic patients aged 41.05 ± 10.4 years were recruited to this two-armed, randomized, controlled intervention trial. Participants were instructed to consume 90 g per day black seed raisin in the intervention group, and control group received no intervention. BP, lipid profile, and plasma levels of TAC, MDA, hs-CRP, and FBS were determined at baseline and week 5.

RESULTS

After 5 weeks, the diastolic BP reduced significantly in raisin group compared with baseline (81.80 ± 10.22 vs 77.05 ± 11.03, P = 0.001) and TAC was significantly increased in raisin group compared with the control group (394 ± 116.93 vs 479 ± 122.31, P = 0.001). The serum level of MDA in the raisin group was significantly lower compared with the control group (1.35 ± 0.88 vs 1.39 ± 0.67, P = 0.039). No significant changes were found in lipid profile, SBP, hs-CRP, and FBS.

CONCLUSION

These results suggest that consumption of black raisin which is rich in polyphenolic compounds has beneficial effects on some cardiovascular risk factors especially blood pressure and serum antioxidant capacity in patients with hyperlipidemia.

TRIAL REGISTRATION

Trial registration number: IRCT2015091624049N1. This study was registered in the Iranian Registry of Clinical Trials (IRCT). URL of trial registry record: https://www.irct.ir/trial/20395.

Efficacy of Polyphenols in the Management of Dyslipidemia: A Focus on Clinical Studies

Polyphenols (PLPs), phytochemicals found in a wide range of plant-based foods, have gained extensive attention in view of their antioxidant, anti-inflammatory, immunomodulatory and several additional beneficial activities. The health-promoting effects noted in animal models of various non-communicable diseases explain the growing interest in these molecules. In particular, in vitro and animal studies reported an attenuation of lipid disorders in response to PLPs. However, despite promising preclinical investigations, the effectiveness of PLPs in human dyslipidemia (DLP) is less clear and necessitates revision of available literature. Therefore, the present review analyzes the role of PLPs in managing clinical DLP, notably by dissecting their potential in ameliorating lipid/lipoprotein metabolism and alleviating hyperlipidemia, both postprandially and in long-term interventions. To this end, PubMed was used for article search. The search terms included polyphenols, lipids, triglycerides, cholesterol, LDL-cholesterol and /or HDL-cholesterol. The critical examination of the trials published to date illustrates certain benefits on blood lipids along with co-morbidities in participant’s health status. However, inconsistent results document significant research gaps, potentially owing to study heterogeneity and lack of rigor in establishing PLP bioavailability during supplementation. This underlines the need for further efforts in order to elucidate and support a potential role of PLPs in fighting DLP.

Aquatic exercise associated or not with grape juice consumption-modulated oxidative parameters in Parkinson disease patients: A randomized intervention study

Parkinson's disease (PD) is a neurodegenerative disorder with significant motor disabilities and cognitive decline. Importantly, the imbalance of oxidative stress is related to PD physiopathology and progression. This study aimed to evaluate the impact of grape juice consumption associated with an aquatic exercise protocol on oxidative stress parameters and cognitive function in individuals with PD. The participants were randomized into two groups: grape juice group (GJG) and control group (CG) and were submitted to 4 weeks of an aquatic intervention (twice a week, approximately 60 minutes/session). The GJG also consumed 400 ml of grape juice per day (integral and conventional) during this period. Cognitive function was assessed by the Montreal Cognitive Assessment (MoCa) questionnaire. For the analysis of oxidative stress markers, specifically lipid oxidative damage (TBARS), proteins (Carbonil), acid uric and the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase), blood collection were done before and after intervention. No changes were observed in cognitive function after intervention in both groups. Regarding biomarkers, a reduction of antioxidant enzymes, thiobarbituric acid reactive substances (TBARS) and uric acid was observed in both groups. However, only the GJG showed a significant reduction on protein oxidation levels after intervention. In conclusion, the consumption of grape juice associated with an aquatic exercise protocol might be consider an effective alternative to reduce the oxidative damage in PD, reinforcing the importance of this intervention in promoting beneficial impact in this population.

Natural products: The role and mechanism in low-density lipoprotein oxidation and atherosclerosis

Atherosclerosis is a chronic inflammatory, metabolic, and epigenetic disease, which leads to the life-threatening coronary artery disease. Emerging studies from bench to bedside have demonstrated the pivotal role of low-density lipoprotein (LDL) oxidation in the initiation and progression of atherosclerosis. This article hereby reviews oxidation mechanism of LDL, and the pro-atherogenic and biomarker role of oxidized LDL in atherosclerosis. We also review the pharmacological effects of several representative natural products (vitamin E, resveratrol, quercetin, probucol, tanshinone IIA, epigallocatechin gallate, and Lycopene) in protecting against LDL oxidation and atherosclerosis. Clinical and basic research supports the beneficial effects of these natural products in inhibiting LDL oxidation and preventing atherosclerosis, but the data are still controversial. This may be related to factors such as the population and the dosage and time of taking natural products involved in different studies. Understanding the mechanism of LDL oxidation and effect of oxidized LDL help researchers to find novel therapies against atherosclerosis.

Grapevine as a Rich Source of Polyphenolic Compounds

Grapes are rich in primary and secondary metabolites. Among the secondary metabolites, polyphenolic compounds are the most abundant in grape berries. Besides their important impacts on grape and wine quality, this class of compounds has beneficial effects on human health. Due to their antioxidant activity, polyphenols and phenolic acids can act as anti-inflammatory and anticancerogenic agents, and can modulate the immune system. In grape berries, polyphenols and phenolic acids can be located in the pericarp and seeds, but distribution differs considerably among these tissues. Although some classes of polyphenols and phenolic acids are under strict genetic control, the final content is highly influenced by environmental factors, such as climate, soil, vineyard, and management. This review aims to present the main classes of polyphenolic compounds and phenolic acids in different berry tissues and grape varieties and special emphasis on their beneficial effect on human health.

Bioactive Compounds of Edible Fruits with Their Anti-Aging Properties: A Comprehensive Review to Prolong Human Life

Aging is a complicated biological process in which functional and structural alterations in a living organism take place over time. Reactive oxygen species is one of the main factors responsible for aging and is associated with several chronic pathologies. The relationship between aging and diet is quite interesting and has attained worldwide attention. Healthy food, in addition to dietary antioxidants, are required to delay the process of aging and improve the quality of life. Many healthy foods such as fruits are a good source of dietary nutrients and natural bioactive compounds which have antioxidant properties and are involved in preventing aging and other age-related disorders. Health benefits linked with healthy consumption of fruit have drawn increased interest. A significant number of studies have documented the advantages of fruit intake, as it suppresses free-radical development that further reduces the oxidative stress created in the body and protects against several types of diseases such as cancer, type 2 diabetes, inflammatory disorders, and other cardiovascular diseases that ultimately prevent aging. In addition, fruits have numerous other properties like anti-inflammatory, anti-cancerous, anti-diabetic, neuroprotective, and have health-promoting effects. Mechanisms of various bioactive compounds that aids in preventing various diseases and increases longevity are also described. This manuscript provides a summary of various bioactive components present in fruits along with their health-promoting and antiaging properties.

Food intake biomarkers for berries and grapes

Grapes and berries are two types of widely consumed fruits characterized by a high content in different phytochemicals. However, their accurate dietary assessment is particularly arduous, because of the already wide recognized bias associated with self-reporting methods, combined with the large range of species and cultivars and the fact that these fruits are popularly consumed not only in fresh and frozen forms but also as processed and derived products, including dried and canned fruits, beverages, jams, and jellies. Reporting precise type and/or quantity of grape and berries in FFQ or diaries can obviously be affected by errors. Recently, biomarkers of food intake (BFIs) rose as a promising tool to provide accurate information indicating consumption of certain food items. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs have been developed within the Food Biomarker Alliance (FoodBAll) Project. This paper aims to evaluate the putative BIFs for blueberries, strawberries, raspberries, blackberries, cranberries, blackcurrant, and grapes. Candidate BFIs for grapes were resveratrol metabolites and tartaric acid. The metabolites considered as putative BFI for berries consumption were mostly anthocyanins derivatives together with several metabolites of ellagitannins and some aroma compounds. However, identification of BFIs for single berry types encountered more difficulties. In the absence of highly specific metabolites reported to date, we suggested some multi-metabolite panels that may be further investigated as putative biomarkers for some berry fruits.

Effects of Maternal Grape Juice Intake on Unfolded Protein Response in the Mammary Glands of Offspring of High Fat Diet Fed Rat Dams

Maternal high fat diet (HFD) and obesity during pregnancy increase female offspring′s mammary cancer risk in animal studies. We aimed to observe whether the consumption of grape juice during pregnancy can reverse this risk. During pregnancy and lactation, female Wistar rats were fed either a control or HFD and also received grape juice or tap water. At the age of 50 days, female offspring were euthanized, and mammary glands were collected to assess changes in biomarkers of increased mammary cancer risk. Maternal HFD increased the number of terminal end buds in offspring’s mammary glands and promoted cell proliferation (ki67). Maternal grape consumption blocked these effects. Apoptosis marker caspase 7, but not caspase 3, was reduced in the HFD offspring. HFD offspring also exhibited a reduction in the indicators of cell cycle regulation (p27, p21) and an ability to maintain DNA integrity (reduced p53). Maternal grape juice did not have any effect on these endpoints in the HFD offspring but reduced caspase 7 and p53 levels in the control offspring, perhaps reflecting reduced cellular stress. Maternal HFD increased oxidative stress marker GPx1 mRNA expression, and grape juice increased the levels of GPx2 in both the control and HFD offspring. HFD increased XBP1/Xbp1s, Atf4 and Atf6 mRNA expression and reduced ATF6 and CHOP protein levels. Maternal grape juice reversed the increase in XBP1/Xbp1s, Atf4 and Atf6 in the HFD offspring. PPARγ was downregulated in the HFD group, and grape juice reversed this effect. Grape juice also reduced the levels of HER2 and IRS, both in the control and HFD offspring. In conclusion, maternal grape juice supplementation reversed some of the biomarkers that are indicative of increased breast cancer risk in the HFD offspring.

Protection of natural antioxidants against low-density lipoprotein oxidation

This chapter reports essential information about the protective action of antioxidants against LDL oxidation. The activity of individual compounds (tocopherols, vitamin C, phenolic compounds) as well as extracts obtained from plant material (cereals, fruits, legumes, nuts, mushrooms, by-products of food industry) is reported. The structure-antioxidant activity relationship of phenolic compounds is discussed. This article summarizes the findings to date of both in vitro and in vivo studies using foods or phenolic extracts isolated from foodstuffs at inhibiting the incidence of LDL oxidation. This chapter summarizes also the reportings to date of in vivo studies using foods or beverages at inhibiting the incidence of LDL oxidation.

Effects of polyphenols on cardio-metabolic risk factors and risk of type 2 diabetes. A joint position statement of the Diabetes and Nutrition Study Group of the Italian Society of Diabetology (SID), the Italian Association of Dietetics and Clinical Nutrition (ADI) and the Italian Association of Medical Diabetologists (AMD)

AIM

A large body of evidence supports a role of polyphenols in the prevention of chronic diseases, i.e. type 2 diabetes (DMT2), cardiovascular diseases and some types of cancer. In the present manuscript, the effect of polyphenol/phenolic compounds on the main cardio-metabolic risk factors (body weight, blood pressure, blood glucose concentrations, plasma lipids, inflammation and oxidative stress) in humans will be discussed.

DATA SYNTHESIS

Epidemiological evidence supports the beneficial effects of polyphenol-rich diets in the prevention of T2D risk. However, the available evidence from randomized controlled clinical trials did not allow the identification of specific phenolic compounds or polyphenol-rich foods that effectively improve cardio-metabolic risk factors. The most promising results in terms of the management of cardio-metabolic risk factors derive from RCTs based on a long-term intake of polyphenol-rich foods and beverages. Therefore, future studies should focus on a diet containing different classes of polyphenols rather than a specific food or phenolic compound. The hypothesis is that a polyphenol-rich diet may have a pleiotropic effect on cardiometabolic risk factors thanks to the specific action of different polyphenol subclasses.

CONCLUSION

The lack of conclusive evidence on the effectiveness of polyphenols in the management of cardio-metabolic risk factors does not allow recommendation of their use as supplements to reduce T2D and CVD risk. However, the daily consumption of naturally polyphenol-rich foods and beverages might be advised according to the current nutritional dietary recommendation.

Impact of Grape Products on Lipid Profile: A Meta-Analysis of Randomized Controlled Studies

Background: Growing evidence shows that grape polyphenols can improve cardiovascular risk factors. Although there are clear data supporting a beneficial effect of grape supplementation on blood pressure and glucose metabolism, the effects of grape polyphenols on lipid metabolism are still controversial. Objective: We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of grape products on lipid profile. Design: A systematic search was performed in the PubMed, Web of Science, Scopus, and EMBASE databases without any language or publication year restriction. The reference lists of all retrieved articles were manually reviewed. RCTs evaluating the impact of grape products/juice/extracts on lipid profile were included. Difference in total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), oxidized low-density lipoprotein cholesterol (oxLDL-C), apolipoprotein (apo) A, apo B before and after administration of grape products or placebo were expressed as mean differences (MD) with pertinent 95% confidence intervals (95% CI). The impact of clinical and demographic features on effect size was assessed by meta-regression. Results: The administration of grape products is associated with a significant improvement of lipid profile, as evidenced by changes in TC (MD: −7.6 mg/dL (−0.2 mmol/L); 95% CI: −10.8, −4.4; p < 0.001), HDL-C (MD: 1.4 mg/dL (0.04 mmol/L); 95% CI: 0.8, 1.9; p < 0.001, I² = 74.7%, p < 0.001), LDL-C (−6.3 mg/dL (−0.16 mmol/L); 95% CI: −9.5, −3.0; p < 0.001), oxLDL-C (MD: −4.5 U/L; 95% CI: −7.5, −1.5; p = 0.003, I² = 90.6%, p < 0.001), apo B (MD: −2.4 mg/dL (−0.05 µmol/L); 95% CI: −4.5, −0.3; p = 0.026), and TG (MD: −14.5 mg/dL (−0.16 mmol/L); 95% CI: −17.7, −11.2; p < 0.001) levels in subjects receiving grape products compared to placebo. With regard to the extent of the lipid-lowering effect, compared to baseline values, the highest reduction was reported for LDL-C (MD: −5.6 mg/dL (−0.14 mmol/L); 95% CI: −9.5, −1.7; p = 0.005) and for oxLDL-C (MD: −5.0 U/L; 95% CI: −8.8, −1.2; p = 0.010, I² = 0%, p = 0.470). Conclusions: Grape polyphenols exert a favorable effect on lipid profile in humans by significantly reducing plasma levels of LDL-C and oxLDL-C.

Oxidative stress in chronic kidney disease

Oxidative stress (OS), defined as disturbances in the pro-/antioxidant balance, is harmful to cells due to the excessive generation of highly reactive oxygen (ROS) and nitrogen (RNS) species. When the balance is not disturbed, OS has a role in physiological adaptations and signal transduction. However, an excessive amount of ROS and RNS results in the oxidation of biological molecules such as lipids, proteins, and DNA. Oxidative stress has been reported in kidney disease, due to both antioxidant depletions as well as increased ROS production. The kidney is a highly metabolic organ, rich in oxidation reactions in mitochondria, which makes it vulnerable to damage caused by OS, and several studies have shown that OS can accelerate kidney disease progression. Also, in patients at advanced stages of chronic kidney disease (CKD), increased OS is associated with complications such as hypertension, atherosclerosis, inflammation, and anemia. In this review, we aim to describe OS and its influence on CKD progression and its complications. We also discuss the potential role of various antioxidants and pharmacological agents, which may represent potential therapeutic targets to reduce OS in both pediatric and adult CKD patients.

The effects of quercetin supplementation on lipid profiles and inflammatory markers among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials

Aims: This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to determine the effect of quercetin administration on lipid profiles and inflammatory markers among patients with metabolic syndrome (MetS) and related disorders.Methods: We searched systematically online databases including Cochrane Library, EMBASE, MEDLINE, and Web of Science to identify the relevant RCTs until November 2018. Q-test and I2 statistics were applied to assess heterogeneity among included studies. Data were combined using fixed- or random-effects model and presented as standardized mean difference (SMD) with 95% confidence interval (CI).Results: Out of 591 citations, 16 RCTs were included in the meta-analysis. The pooled findings showed that quercetin consumption significantly decreased total-cholesterol (SMD = -0.98; 95% CI, -1.48, -0.49; p < 0.001; I2: 94.0), LDL-cholesterol (SMD = -0.88; 95% CI, -1.35, -0.41; p < 0.001; I2: 92.7) and C-reactive protein (CRP) levels (-0.64; 95% CI, -1.03, -0.25; p = 0.001; I2: 90.2). While, quercetin supplementation did not significantly affect triglycerides (TG) (SMD = -0.32; 95% CI, -0.68, 0.04; p = 0.08; I2: 84.8), HDL-cholesterol (SMD = 0.20; 95% CI, -0.20, 0.24; p = 0.84; I2: 70.6), interleukin 6 (IL-6) (SMD = -0.69; 95% CI, -1.69, 0.31; p = 0.17; I2: 94.5) and tumor necrosis factor-alpha (TNF-α) levels (SMD = -0.06; 95% CI, -0.25, 0.14; p = 0.58; I2: 35.6)Conclusions: In summary, the current meta-analysis demonstrated that quercetin supplementation significantly reduced total-cholesterol, LDL-cholesterol, and CRP levels, yet did not affect triglycerides, HDL-cholesterol, IL-6 and TNF-α among patients with MetS and related disorders.

Serum Oxidative-Antioxidative Status in Patients With Alkaptonuria

Background

Alkaptonuria (AKU) is a rare genetic disease associated with the deposition of melanin-like pigments (ochronosis) in connective tissues. However, data regarding the effect of oxidative stress products on disease pathogenesis are limited. The purpose of this study was to investigate oxidative stress and related factors in patients with alkaptonuria and compare the findings with those in healthy control subjects.

Methods

The study sample comprised of 21 AKU patients and 19 age- and sex-matched healthy controls. Serum samples were obtained to detect the total antioxidative capacity (TAC), and oxidation degradation products of thiobarbituric acid-reactive substances, protein carbonyls, advanced oxidation protein products, and homogentisic acid levels in urine were determined.

Results

Serum TAC, oxidation degradation products of thiobarbituric acid-reactive substances, and protein carbonyl levels in the AKU group were higher than those measured for the control subjects, and the difference was statistically significant (P < 0.05). Moreover, a positive correlation was found between the patient's serum protein carbonyl, patient's age and AKU severity score (r = 0.492 and 0.746, respectively; P < 0.05). Furthermore, the protein carbonyl serum levels can be used to predict the disease severity score in alkaptonuria patients (P < 0.05).

Conclusions

In sum, the study results provide further support for the role of oxidation in the pathogenesis of alkaptonuria, suggesting presence of a more complex relationship than what has been previously assumed. Thus, further studies are needed to clarify these conflicting results.

Antioxidant Supplementation in Renal Replacement Therapy Patients: Is There Evidence?

The disruption of balance between production of reactive oxygen species and antioxidant systems in favor of the oxidants is termed oxidative stress (OS). To counteract the damaging effects of prooxidant free radicals, all aerobic organisms have antioxidant defense mechanisms that are aimed at neutralizing the circulating oxidants and repair the resulting injuries. Antioxidants are either endogenous (the natural defense mechanisms produced by the human body) or exogenous, found in supplements and foods. OS is present at the early stages of chronic kidney disease, augments progressively with renal function deterioration, and is further exacerbated by renal replacement therapy. End-stage renal disease patients, on hemodialysis (HD) or peritoneal dialysis (PD), suffer from accelerated OS, which has been associated with increased risk for mortality and cardiovascular disease. During HD sessions, the bioincompatibility of dialyzers and dialysate trigger activation of white blood cells and formation of free radicals, while a significant loss of antioxidants is also present. In PD, the bioincompatibility of solutions, including high osmolality, elevated lactate levels, low pH, and accumulation of advanced glycation end-products trigger formation of prooxidants, while there is significant loss of vitamins in the ultrafiltrate. A number of exogenous antioxidants have been suggested to ameliorate OS in dialysis patients. Vitamins B, C, D, and E, coenzyme Q10, L-carnitine, a-lipoic acid, curcumin, green tea, flavonoids, polyphenols, omega-3 polyunsaturated fatty acids, statins, trace elements, and N-acetylcysteine have been studied as exogenous antioxidant supplements in both PD and HD patients.

Effects of grape products on blood lipids: a systematic review and dose–response meta-analysis of randomized controlled trials

Grape products through several plausible mechanisms-of-action are reported to improve lipid profile. The present systematic review revealed that grape product supplementation might have a positive effect on achieving a lipid profile target.

Apple intake improves antioxidant parameters in hemodialysis patients without affecting serum potassium levels

Oxidative stress (OS) is associated with increased morbidity and mortality in hemodialysis (HD) patients, and the consumption of fruits seems to improve OS due to their antioxidant properties. Therefore, we hypothesized that Fuji apple intake improves OS markers in HD patients due to its polyphenolic compounds without increasing serum potassium levels. This trial was a 1-group, pre- and posttest comparison between 16 patients who had been on hemodialysis for at least 3 months without any acute illness or hyperkalemia. Each volunteer consumed 2 Fuji apples (~360 g) per day for 1 week. Blood samples were collected at the baseline period and after 8 days for the measurement of total antioxidant status, ascorbic acid, catalase, glutathione peroxidase, superoxide dismutase, reduced glutathione, total oxidant status, oxidative stress index, potassium, phosphorus, uric acid, glucose, and fructosamine. For tolerance evaluation, participants were asked about their bowel habits. Apple intake increased glutathione peroxidase (P = .006) and superoxide dismutase activities (P = .006) and ascorbic acid levels (P = .002). No significant changes were observed in uric acid, potassium, phosphorus, glucose, and fructosamine levels. Additionally, there was a decrease in the catalase activity (P = .021) and in the total antioxidant status values (P = .004). However, increased total oxidant status (P = .003) and oxidative stress index (P = .033) levels were observed after apple intake. In conclusion, the intake of 2 Fuji apples per day for 1 week was well tolerated and improved antioxidant parameters in HD patients without affecting serum potassium levels.

Grape Juice Consumption with or without High Fat Diet during Pregnancy Reduced the Weight Gain and Improved Lipid Profile and Oxidative Stress Levels in Liver and Serum from Wistar Rats

The aim of this study was to evaluate the effects of high fat diet with or without grape juice during the pregnancy on gestational weight gain, biochemical parameters, and oxidative stress in plasma and liver from Wistar rats. Forty-nine rats were divided into four groups: control diet group (CD), high fat diet (HFD), grape juice and control diet (PGJCD), and grape juice and high fat diet (PGJHFD). During the treatment the weight gain of the rats was tracked. They had free access to their respective diets during 42 days of treatment. After offspring weaning, the mother rats were euthanized and blood and liver were collected. The high fat diet increased the total cholesterol and triglycerides serum levels as well as carbonyl levels in the liver, however this diet reduced the high-density lipoprotein (HDL) and urea levels in serum. Grape juice consumption reduced gestational body weight gain. In liver, the juice consumption increased sulfhydryl levels and reduced the superoxide dismutase (SOD) activity and TBARS level, in serum the consumption reduced aspartate aminotransferase (AST) and TBARS. We can conclude that the consumption of a diet rich in fat can promotes harmful effects on health during pregnancy, however the consumption of grape juice seems to be an important alternative to prevent oxidative damages and to promote the improvement of health.

Alterations on phenolic compounds and antioxidant activity during sour grape juice concentrate processing

The alterations of phenolic compounds and antioxidant capacity of sour grape juice were investigated during the concentration process stages. Phenolics and antioxidant properties of the samples changed more at the vacuum evaporation stage than that of the other stages. After evaporation, the antioxidant capacity of the samples decreased approximately between 14.2 and 17.0 % for DPPH and ABTS methods, respectively. Besides, phenolic contents also decreased approximately as 14.8%. HPLC data on phenolics of sour grape juice during concentrate processing gave 12 polyphenols, including gallic acid, (+)-catechin, (-)-epigallocatechin, vanillic acid, (-)-epigallocatechin gallate, (-)-epicatechin, caftaric acid, caffeic acid and p-coumaric acid, which were determined as 1.05-1.83 mg/100 g, 5.40-7.83 mg/100 g, 6.35-9.21 mg/100 g, 3.01-5.18 mg/100 g, 0- 1.95 mg/100 g, 2.33-3.54 mg/100 g, 12.40-37.60 mg/100 g, 1.44-2.26 mg/100 g and 0.27-0.44 mg/100 g, respectively. Ferulic, sinapic acids and quercetin were only detected at concentrate step of the sour grape juice processing and were found as 0.18 mg/100 g, 0.28 mg/100 g and 0.76 mg/100 g, respectively.