Combining Conventional Organic Solvent Extraction, Ultrasound-Assisted Extraction, and Chromatographic Techniques to Obtain Pure Betanin from Beetroot for Clinical Purposes.

Red beetroot extract (E162) is a natural colorant that owes its color to betanin, its major red pigment. Betanin displays remarkable antioxidant, anti-inflammatory, and chemoprotective properties mediated by its structure and influence on gene expression. However, the betanin employed in most preclinical assays is a beetroot extract diluted in dextrin, not pure betanin, as no isolated compound is commercially available. This makes its use inaccurate concerning product content estimates and biological effect assessments. Herein, a combination of conventional extraction under orbital shaking and ultrasound-assisted extraction (UAE) to purify betanin by semi-preparative HPLC was performed. The employed methodology extracts betalains at over a 90% yield, achieving 1.74 ± 0.01 mg of pure betanin/g beetroot, a 41% yield from beetroot contents increasing to 50 %, considering the betalains pool. The purified betanin exhibited an 85% purity degree against 32 or 72% of a commercial standard evaluated by LC-MS or HPLC methods, respectively. The identity of purified betanin was confirmed by UV-Vis, LC-MS, and 1H NMR. The combination of a conventional extraction, UAE, and semi-preparative HPLC allowed for betanin purification with a high yield, superior purity, and almost three times more antioxidant power compared to commercial betanin, being, therefore, more suitable for clinical purposes.

A Critical Review on Vasoactive Nutrients for the Management of Endothelial Dysfunction and Arterial Stiffness in Individuals under Cardiovascular Risk.

Pathophysiological conditions such as endothelial dysfunction and arterial stiffness, characterized by low nitric oxide bioavailability, deficient endothelium-dependent vasodilation and heart effort, predispose individuals to atherosclerotic lesions and cardiac events. Nitrate (NO3-), L-arginine, L-citrulline and potassium (K+) can mitigate arterial dysfunction and stiffness by intensifying NO bioavailability. Dietary compounds such as L-arginine, L-citrulline, NO3- and K+ exert vasoactive effects as demonstrated in clinical interventions by noninvasive flow-mediated vasodilation (FMD) and pulse-wave velocity (PWV) prognostic techniques. Daily L-arginine intakes ranging from 4.5 to 21 g lead to increased FMD and reduced PWV responses. Isolated L-citrulline intake of at least 5.6 g has a better effect compared to watermelon extract, which is only effective on endothelial function when supplemented for longer than 6 weeks and contains at least 6 g of L-citrulline. NO3- supplementation employing beetroot at doses greater than 370 mg promotes hemodynamic effects through the NO3--NO2-/NO pathway, a well-documented effect. A potassium intake of 1.5 g/day can restore endothelial function and arterial mobility, where decreased vascular tone takes place via ATPase pump/hyperpolarization and natriuresis, leading to muscle relaxation and NO release. These dietary interventions, alone or synergically, can ameliorate endothelial dysfunction and should be considered as adjuvant therapies in cardiovascular diseases.

Microencapsulated and Ready-to-Eat Beetroot Soup: A Stable and Attractive Formulation Enriched in Nitrate, Betalains and Minerals.

Beetroot is a tuber rich in antioxidant compounds, i.e., betanin and saponins, and is one of the main sources of dietary nitrate. The aim of the present study was to microencapsulate a ready-to-eat beetroot soup by lyophilization using different encapsulating agents, which supply the required amount of bioactive nutrients. Particle size distributions ranged from 7.94 ± 1.74 to 245.66 ± 2.31 µm for beetroot soup in starch and from 30.56 ± 1.66 to 636.34 ± 2.04 µm in maltodextrin. Microparticle yields of powdered beetroot soup in starch varied from 77.68% to 88.91%, and in maltodextrin from 75.01% to 80.25%. The NO3- and total betalain contents at a 1:2 ratio were 10.46 ± 0.22 mmol·100 g-1 fresh weight basis and 219.7 ± 4.92 mg·g-1 in starch powdered beetroot soup and 8.43 ± 0.09 mmol·100 g-1 fresh weight basis and 223.9 ± 4.21 mg·g-1 in maltodextrin powdered beetroot soup. Six distinct minerals were identified and quantified in beetroot soups, namely Na, K, Mg, Mn, Zn and P. Beetroot soup microencapsulated in starch or maltodextrin complied with microbiological quality guidelines for consumption, with good acceptance and purchase intention throughout 90 days of storage. Microencapsulated beetroot soup may, thus, comprise a novel attractive strategy to offer high contents of bioaccessible dietary nitrate and antioxidant compounds that may aid in the improvement of vascular-protective effects.

Increasing the Power of Polyphenols through Nanoencapsulation for Adjuvant Therapy against Cardiovascular Diseases.

Polyphenols play a therapeutic role in vascular diseases, acting in inherent illness-associate conditions such as inflammation, diabetes, dyslipidemia, hypertension, and oxidative stress, as demonstrated by clinical trials and epidemiological surveys. The main polyphenol cardioprotective mechanisms rely on increased nitric oxide, decreased asymmetric dimethylarginine levels, upregulation of genes encoding antioxidant enzymes via the Nrf2-ARE pathway and anti-inflammatory action through the redox-sensitive transcription factor NF-κB and PPAR-γ receptor. However, poor polyphenol bioavailability and extensive metabolization restrict their applicability. Polyphenols carried by nanoparticles circumvent these limitations providing controlled release and better solubility, chemical protection, and target achievement. Nano-encapsulate polyphenols loaded in food grade polymers and lipids appear to be safe, gaining resistance in the enteric route for intestinal absorption, in which the mucoadhesiveness ensures their increased uptake, achieving high systemic levels in non-metabolized forms. Nano-capsules confer a gradual release to these compounds, as well as longer half-lives and cell and whole organism permanence, reinforcing their effectiveness, as demonstrated in pre-clinical trials, enabling their application as an adjuvant therapy against cardiovascular diseases. Polyphenol entrapment in nanoparticles should be encouraged in nutraceutical manufacturing for the fortification of foods and beverages. This study discusses pre-clinical trials evaluating how nano-encapsulate polyphenols following oral administration can aid in cardiovascular performance.

Short-Term Betanin Intake Reduces Oxidative Stress in Wistar Rats.

Oxidative stress is a common condition described in risk factors for cardiovascular disease. Betanin, a bioactive pigment from red beetroot demonstrates anti-inflammatory and antioxidant properties. The main aim of this study was to evaluate the short-term intake of betanin against oxidative stress in a rodent model, a common condition described in several risk factors for cardiovascular disease. Oxidative stress was induced in Wistar rats by a hyperlipidemic diet for 60 days, followed by betanin administration (20 mg·kg-1) through oral gavage for 20 days. Plasma biochemical parameters and antioxidant enzyme activities were evaluated. Lipid peroxidation and histopathological changes were determined in the liver. The hyperlipidemic diet caused hyperglycemia, hyperinsulinemia, insulin resistance, and increases in alanine transaminase and aspartate transaminase levels. Oxidative stress status was confirmed by reduction of antioxidant enzyme activities, increased lipid peroxidation, and liver damage. Purified betanin regulated glucose levels, insulin, and insulin resistance. Hepatic damage was reversed as evidenced by the reduction in alanine transaminase and aspartate transaminase levels and confirmed by histological analyses. Betanin reduced hepatic malondialdehyde and increased superoxide dismutase, catalase, and glutathione peroxidase activities. Short-term betanin intake modulated biochemical parameters, reversed hepatic tissue damage, and attenuated oxidative stress in Wistar rats.

Hormonal response to L-arginine supplementation in physically active individuals.

BACKGROUND: Nutritional supplements based on the amino acid L-arginine have been hypothesized to improve exercise performance by increasing levels of insulin and growth hormone (GH). Changes of these parameters in response to L-arginine supplementation may clarify the mechanisms underlying its putative physiological effects on physical performance. OBJECTIVE: The aim of the study was to evaluate the effect of L-arginine supplementation on serum insulin, GH, Growth Factor Insulin-like (IGF-1), and cortisol in response to exercise. Exercise performance was also evaluated. DESIGN: Fifteen trained runners were divided into groups supplemented with 6 g of L-arginine (ARG) or placebo (PLA). Blood samples were collected before supplementation (T0), immediately after the first exercise session (T1), after the second exercise session (T2), and after 20 min of rest (T3). The exercise consisted of two bouts of 5 km time-trial running test. RESULTS: There was a significant increase in serum GH (T0: 3.28±0.95 vs. 3.21±0.5 ng/mL; T1: 4.35±0.23 vs. 4.17±0.13 ng/mL; T2: 4.22±0.25 vs. 4.17±0.09 ng/mL; T3: 4.14±0.29 vs. 4.13±0.18 ng/mL) and cortisol (T0: 198.71±53.77 vs. 207.57±69.51 nmol/L; T1: 458.16±116.12 vs. 433.26±101.77 nmol/L; T2: 454.61±125.21 vs. 431.88±74.82 nmol/L; T3: 311.14±102.91 vs. 362.26±110.42 nmol/L) after T1, T2, and T3, with no significant difference between the ARG and PLA groups, respectively. There was also no significant difference observed in the variables of IGF-1, insulin, and total running time between the ARG and PLA groups. CONCLUSIONS: The supplementation of L-arginine did not appear to stimulate the production of insulin, GH, and IGF-1 and, thus, provided no benefit in hormonal response or exercise performance in trained runners.