Profile and Content of Betalains in Plasma and Urine of Volunteers after Long-Term Exposure to Fermented Red Beet Juice

Bioavailability and excretion profile of betacyanins - Variability and correlations between different excretion routes

The present study addresses the knowledge gap in betalain bioavailability, transformation and excretion. Analysis of renal and fecal excretion profiles in humans after consumption of beetroot revealed very low bioavailability (renal recovery of 0.13 %) and fast elimination of pigments (renal elimination rate constant of 0.16 h-1), while the majority of betalains underwent severe depletion during GI transit, evidenced by decarboxylation, deglucosidation and dehydrogenation. Betacyanin metabolite levels in human urine were positively associated with those in stools (p < 0.05), indicating significant impact of pigment metabolism in the gut on their bioavailability. In addition, the current study revealed large inter-individual and compositional variabilities of pigment after colonic fermentation compared with systemic metabolism, likely attributed to the increasing complexity of intestinal environment with diverse gut microbiota. To conclude, intestinal uptake and systemic metabolism of betacyanins are intimately associated with their intestinal biotransformation, with gut microbiota serving as a crucial factor.

Unveiling Alternative Oxidation Pathways and Antioxidant and Cardioprotective Potential of Amaranthin-Type Betacyanins from Spinach-like Atriplex hortensis var. 'Rubra'

A comprehensive oxidation mechanism was investigated for amaranthin-type betacyanins with a specific glucuronosylglucosyl moiety isolated from Atriplex hortensis 'rubra' using liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) and LC-Quadrupole-Orbitrap-MS (LC-Q-Orbitrap-MS). By employing one-dimensional (1D) and two-dimensional (2D) NMR, this study elucidates the chemical structures of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)-oxidized celosianins for the first time. These findings demonstrate alternative oxidation pathways for acylated betacyanins compared to well-known betanidin, betanin, and gomphrenin pigments. Contrary to previous research, we uncover the existence of 17-decarboxy-neo- and 2,17-bidecarboxy-xanneo-derivatives as the initial oxidation products without the expected 2-decarboxy-xan forms. These oxidized compounds demonstrated potent free radical scavenging properties. Celosianin (IC50 = 23 μg/mL) displayed slightly higher antioxidant activity compared to oxidized forms, 17-decarboxy-neocelosianin (IC50 = 34 μg/mL) and 2,17-bidecarboxy-xanneocelosianin (IC50 = 29 μg/mL). The oxidized compounds showed no cytotoxic effects on H9c2 rat cardiomyoblasts (0.1-100 μg/mL). Additionally, treatment of H9c2 cells with the oxidized compounds (0.1-10 μg/mL) elevated glutathione levels and exhibited protective effects against H2O2-induced cell death. These findings have significant implications for understanding the impact of oxidation processes on the structures and biological activities of acylated betalains, providing valuable insights for future studies of the bioavailability and biological mechanism of their action in vivo.

Effect of two-week red beetroot juice consumption on modulation of gut microbiota in healthy human volunteers - A pilot study

With very little research exploring intestinal effects of red beetroot consumption, the present pilot study investigated gut microbial changes following red beetroot consumption, via a 14-day intervention trial in healthy adults. Compared to baseline, the study demonstrates transient changes in abundance of some taxa e.g., Romboutsia and Christensenella, after different days of intervention (p < 0.05). Enrichment of Akkermansia muciniphila and decrease of Bacteroides fragilis (p < 0.05) were observed after 3 days of juice consumption, followed by restoration in abundance after 14 days. With native betacyanins and catabolites detected in stool after juice consumption, betacyanins were found to correlate positively with Bifidobacterium and Coprococcus, and inversely with Ruminococcus (p < 0.1), potentiating a significant rise in (iso)butyric acid content (172.7 ± 30.9 µmol/g stool). Study findings indicate the potential of red beetroot to influence gut microbial populations and catabolites associated with these changes, emphasizing the potential benefit of red beetroot on intestinal as well as systemic health.

Molecular and Antioxidant Characterization of Opuntia robusta Fruit Extract and Its Protective Effect against Diclofenac-Induced Acute Liver Injury in an In Vivo Rat Model

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS^•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury.

Uptake and Immunomodulatory Properties of Betanin, Vulgaxanthin I and Indicaxanthin towards Caco-2 Intestinal Cells

The present study aimed to compare the absorption and transport patterns of three main betalains, betanin, vulgaxanthin I and indicaxanthin, into intestinal epithelial cells and to assess their distinct molecular effects on inflammatory and redox-related cell signalling in association with their radial scavenging potencies. All three betalains showed anti-inflammatory effects (5–80 μM), reflected by attenuated transcription of pro-inflammatory mediators such as cyclooxygenase-2 and inducible NO-synthase. Concomitant increases in antioxidant enzymes such as heme oxygenase-1 were only observed for betanin. Moreover, betanin uniquely demonstrated a potent dose-dependent radical scavenging activity in EPR and cell-based assays. Results also indicated overall low permeability for the three betalains with P_app of 4.2–8.9 × 10⁻⁷ cm s⁻¹. Higher absorption intensities of vulgaxanthin and indicaxanthin may be attributed to smaller molecular sizes and greater lipophilicity. In conclusion, betanin, vulgaxanthin I and indicaxanthin have differentially contributed to lowering inflammatory markers and mitigating oxidative stress, implying the potential to ameliorate inflammatory intestinal disease. Compared with two betaxanthins, the greater efficacy of betanin in scavenging radical and promoting antioxidant response might, to some extent, compensate for its poorer absorption efficiency, as demonstrated by the Caco-2 cell model.

Application of an In Vitro Digestion Model for Wheat and Red Beetroot Bread to Assess the Bioaccessibility of Aflatoxin B1, Ochratoxin A and Zearalenone and Betalains

Nowadays, the bakery industry includes different bioactive ingredients to enrich the nutritional properties of its products, such as betalains from red beetroot (Beta vulgaris). However, cereal products are considered a major route of exposure to many mycotoxins, both individually and in combination, due to their daily consumption, if the cereals used contain these toxins. Only the fraction of the contaminant that is released from the food is bioaccessible and bioavailable to produce toxic effects. Foods with bioactive compounds vary widely in chemical structure and function, and some studies have demonstrated their protective effects against toxics. In this study the bioaccessibility and bioavailability of three legislated mycotoxins (AFB₁, OTA and ZEN), individual and combined, in two breads, one with wheat flour and the other with wheat flour enriched with 20% Beta vulgaris, were evaluated. Bioaccessibility of these three mycotoxins from wheat bread and red beet bread enriched individually at 100 ng/g was similar between the breads: 16% and 14% for AFB1, 16% and 17% for OTA and 26% and 22% for ZEN, respectively. Whereas, when mycotoxins were co-present these values varied with a decreasing tendency: 9% and 15% for AFB1, 13% and 9% for OTA, 4% and 25% for ZEN in wheat bread and in red beet bread, respectively. These values reveal that the presence of other components and the co-presence of mycotoxins can affect the final bioavailability; however, it is necessary to assess this process with in vivo studies to complete the studies.

Betalain-rich dragon fruit (pitaya) consumption improves vascular function in men and women: a double-blind, randomized controlled crossover trial

BACKGROUND

Betalains are natural red color pigments abundant in red-fleshed dragon fruit (Hylocereus polyrhizus). Recent research has shown that dragon fruit consumption may help improve blood glucose and lipid profile. However, investigations of its cardioprotective properties in human trials, especially in nutritionally achievable amounts, remain nonexistent.

OBJECTIVES

The aim of this study was to investigate the effects of acute and short-term consumption of dragon fruit on vascular function in a healthy population.

METHODS

A randomized, double-blind, placebo-controlled, crossover trial was conducted in 19 young, healthy, nonsmoking men and women assigned to consume 24 g whole dragon fruit powder (33 mg betalains) or a nutrient-matched placebo, daily for 14 d. Flow-mediated dilation (FMD), arterial stiffness, and blood pressure (BP) were measured at 0 h, 1 h, 2 h, 3 h, and 4 h and finally at 14 d after daily consumption.

RESULTS

A total of 18 participants completed the trial. Dragon fruit consumption significantly improved acute FMD at 2 h (+0.8 ± 0.3%, P = 0.01), 3 h (+1.0 ± 0.3%, P = 0.001), and 4 h (+1.3 ± 0.4%, P < 0.001) postconsumption compared with placebo. This effect was sustained up until 14 d (+1.3 ± 0.2%, P < 0.001). Pulse-wave velocity was acutely significantly reduced at 3 h (-0.5 ± 0.2 m/s, P = 0.003), whereas augmentation index (AIx) also improved after 14 d (-7.0 ± 3.3%, P = 0.02) when compared with placebo. No differences were found in either peripheral or central BP across all time points.

CONCLUSIONS

Acute and short-term consumption of dragon fruit in dietary achievable amounts improved endothelial function and arterial stiffness in healthy individuals. This implies that regular dragon fruit consumption may have a meaningful impact on cardiovascular disease risk likely due to the high betalain content. This trial was registered at ClinicalTrials.gov as NCT03995602.

Nanomedicine of Plant Origin for the Treatment of Metabolic Disorders

Metabolic disorders are major clinical challenges of health that are progressing globally. A concurrence of metabolic disorders such as obesity, insulin resistance, atherogenic dyslipidemia, and systematic hypertension leads to metabolic syndrome. Over the past years, the metabolic syndrome leads to a five- and two-fold rise in diabetes mellitus type II and cardiovascular diseases. Natural products specifically plant extracts have insulin-sensitizing, anti-inflammatory, and antioxidant properties and are also considered as an alternative option due to few adverse effects. Nanotechnology is one of the promising strategies, which improves the effectiveness of treatment and limits side effects. This review mainly focuses on plant extract-based nanosystems in the management of the metabolic syndrome. Numerous nano-drug delivery systems, i.e., liposomes, hydrogel nanocomposites, nanoemulsions, micelles, solid lipid, and core–shell nanoparticles, have been designed using plant extracts. It has been found that most of the nano-formulations successfully reduced oxidative stress, insulin resistance, chronic inflammation, and lipid profile in in vitro and in vivo studies as plant extracts interfere with the pathways of metabolic syndrome. Thus, these novel plant-based nanosystems could act as a promising candidate for clinical applications.

Potential of Beetroot and Blackcurrant Compounds to Improve Metabolic Syndrome Risk Factors

Metabolic syndrome (MetS) is a group of metabolic abnormalities, which together lead to increased risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM), as well as reduced quality of life. Dietary nitrate, betalains and anthocyanins may improve risk factors for MetS and reduce the risk of development of CHD and T2DM. Beetroot is a rich source of dietary nitrate, and anthocyanins are present in high concentrations in blackcurrants. This narrative review considers the efficacy of beetroot and blackcurrant compounds as potential agents to improve MetS risk factors, which could lead to decreased risk of CHD and T2DM. Further research is needed to establish the mechanisms through which these outcomes may occur, and chronic supplementation studies in humans may corroborate promising findings from animal models and acute human trials.

A systematic review to identify biomarkers of intake for fermented food products

Background

Fermented foods are ubiquitous in human diets and often lauded for their sensory, nutritious, and health-promoting qualities. However, precise associations between the intake of fermented foods and health have not been well-established. This is in part due to the limitations of current dietary assessment tools that rely on subjective reporting, making them prone to memory-related errors and reporting bias. The identification of food intake biomarkers (FIBs) bypasses this challenge by providing an objective measure of intake. Despite numerous studies reporting on FIBs for various types of fermented foods and drinks, unique biomarkers associated with the fermentation process (“fermentation-dependent” biomarkers) have not been well documented. We therefore conducted a comprehensive, systematic review of the literature to identify biomarkers of fermented foods commonly consumed in diets across the world.

Results

After title, abstract, and full-text screening, extraction of data from 301 articles resulted in an extensive list of compounds that were detected in human biofluids following the consumption of various fermented foods, with the majority of articles focusing on coffee (69), wine (69 articles), cocoa (62), beer (34), and bread (29). The identified compounds from all included papers were consolidated and sorted into FIBs proposed for a specific food, for a food group, or for the fermentation process. Alongside food-specific markers (e.g., trigonelline for coffee), and food-group markers (e.g., pentadecanoic acid for dairy intake), several fermentation-dependent markers were revealed. These comprised compounds related to the fermentation process of a particular food, such as mannitol (wine), 2-ethylmalate (beer), methionine (sourdough bread, cheese), theabrownins (tea), and gallic acid (tea, wine), while others were indicative of more general fermentation processes (e.g., ethanol from alcoholic fermentation, 3-phenyllactic acid from lactic fermentation).

Conclusions

Fermented foods comprise a heterogeneous group of foods. While many of the candidate FIBs identified were found to be non-specific, greater specificity may be observed when considering a combination of compounds identified for individual fermented foods, food groups, and from fermentation processes. Future studies that focus on how fermentation impacts the composition and nutritional quality of food substrates could help to identify novel biomarkers of fermented food intake.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-021-00686-4.

Beetroot, a Remarkable Vegetable: Its Nitrate and Phytochemical Contents Can be Adjusted in Novel Formulations to Benefit Health and Support Cardiovascular Disease Therapies

The cardioprotective effects of dietary nitrate from beetroot in healthy and hypertensive individuals are undeniable and irrefutable. Nitrate and nitrate-derived nitrite are precursors for nitric oxide synthesis exhibiting an effect on cardiomyocytes and myocardial ischemia/reperfusion, improving endothelial function, reducing arterial stiffness and stimulating smooth muscle relaxation, decreasing systolic and diastolic blood pressures. Beetroot phytochemicals like betanin, saponins, polyphenols, and organic acids can resist simulated gastrointestinal digestion, raising the hypothesis that the cardioprotective effects of beetroots result from the combination of nitrate/nitrite and bioactive compounds that limit the generation of reactive oxygen species and modulate gene expression. Nitrate and phytochemical concentrations can be adjusted in beet formulations to fulfill requirements for acute or long-term supplementations, enhancing patient adherence to beet intervention. Based on in vitro, in vivo, and clinical trials, beet nitrate and its bioactive phytochemicals are promising as a novel supportive therapy to ameliorate cardiovascular diseases.

The effects of betalain-rich cacti (dragon fruit and cactus pear) on endothelial and vascular function: a systematic review of animal and human studies

Dragon fruit (Hylocereus) and cactus pear (Opuntia) are cacti species that have been widely used globally as a reliable source of food as well as traditional folk remedies. They have become of scientific interest recently due to their high levels of bioactive phytochemical compounds, in particular betalains. Earlier systematic reviews have explored the impact of supplementation of these cactus species on obesity, type-2 diabetes mellitus and cardiovascular risk factors: body weight and composition, serum triglycerides, cholesterol, blood glucose and blood pressure. However, effects on vascular health and endothelial function have yet to be reviewed. In order to address this gap in the literature, a systematic review has been conducted to evaluate the physiological effects of Hylocereus and Opuntia cacti on endothelial and vascular function in in vivo animal models and human studies. An electronic search was performed in the following databases: PubMed (MEDLINE), EMBASE (via Ovid), CINAHL, Scopus, Web of Science®, and The Cochrane Library (CENTRAL). All journals were searched since inceptions up to January 2020 without language restriction. Outcomes of interest were blood pressure, arterial stiffness, vascular reactivity and biochemical markers of endothelial dysfunction. Two investigators independently performed the study selection and data extraction. From 394 references, only 16 studies (9 animal and 7 human) fulfilled the eligibility criteria. Animal studies suggested a potential increase in vasodilation and serum nitric oxide and a reduction in vascular stiffness and blood pressure. The small number of human studies showed a reduction in heart rate as well as an increase in heart rate variability. Although these findings appear to indicate improvement in vascular health, there is a severe lack of robust, randomised human intervention studies to identify underlying mechanisms, optimal dose and long-term effects of cacti consumption.

A review on bioactive compounds of beet (Beta vulgaris L. subsp. vulgaris) with special emphasis on their beneficial effects on gut microbiota and gastrointestinal health

This review discusses the available literature concerning the bioactive compounds of beet (Beta vulgaris L.) and their ability to modulate the gut microbiota and parameters indicative of gastrointestinal health. Data of published literature characterize beet as a source of a variety of bioactive compounds (e.g. diet fiber, pectic-oligosaccharides, betalains and phenolics) with proven beneficial effects on human health. Beet extracts and pectin and pectic-oligosaccharides from beet have shown able to modulate positively gut microbiota composition and activity, with noticeable bifidogenic effects, in addition to stimulate the growth and metabolism of probiotics. Beet betalains and phenolics seem to increase the production of metabolites (e.g. short chain fatty acids) by gut microbiota and probiotics, which are linked with different beneficial effects on host health. The outstanding contents of betalains and phenolics with antioxidant, anti-inflammatory and anti-carcinogenic properties have been linked to the positive effects of beet on gastrointestinal health. Beet should be a healthy choice for use in domestic meal preparations and a source of ingredients to formulate added-value functionalized food products.

Effects of betalains on atherogenic risk factors in patients with atherosclerotic cardiovascular disease

This study evaluated the potential impacts of supplementation with betalain-rich extracts of foods on some atherosclerotic risk factors in coronary artery disease patients. During an acute phase, 48 male patients received about 50 mg betalain/betacyanin, and their blood and urine samples were collected at 3, 8, and 24 hours after supplementations. Also, in a pilot randomized crossover trial, these participants were allocated to two-week interventions (a betacyanin-rich supplement of Opuntia stricta, a betalain-rich supplement of red beetroot and a placebo) with two-week washout periods. Then, their plasma samples were collected at the baseline after a two-week period. The concentrations of betanin in plasma and urine samples were determined using HPLC. Also, homocysteine and glucose levels, lipid profile, and blood pressure were analyzed. Additionally, quality of life and dietary intake were assessed. After these interventions, minimal amounts of betanin were found in plasma and about 0.13-0.93% in urine. Also, both supplements significantly decreased the concentration of homocysteine, glucose, total cholesterol, triglyceride, and LDL. Also, betalain-rich supplements lowered both systolic and diastolic blood pressures. Nevertheless, the clinically meaningful changes were only found in the case of Hcy, LDL, and non-HDL-c concentrations. It seems that food sources of betalains can be considered as functional foods because they improve the lipid profile and levels of homocysteine, glucose, blood pressure, and quality of life to some extent.

Characterization of the profile and concentration of betacyanin in the gastric content, blood and urine of rats after an intragastric administration of fermented red beet juice

The aim of the study was to evaluate the profile and level of betacyanins in the gastric content, blood (portal and main veins) and urine of rats after an intragastric administration of fermented red beet juice with various betacyanin doses. Samples were collected within 2 h after juice administration into the stomachs, separated from the digestive tract of a living rat. In the gastric content, betacyanins administered underwent intensive degradation and changes in their profile, as a result of the conditions prevailing in the stomach and the intensity of the absorption process. Detection of 19 betacyanins (8 native compounds and 11 metabolites) in rats' physiological fluids with the HPLC-MS/MS method proves betacyanin absorption from the stomach. In addition, the study results suggest that betacyanin dose affects the rate and extent of betacyanin degradation in the gastric content, as well as the intensity of absorption, metabolism and excretion of these pigments.