Saponin and Fatty Acid Profiling of the Sea Cucumber Holothuria atra, α-Glucosidase Inhibitory Activity and the Identification of a Novel Triterpene Glycoside.

Saponin-rich sea cucumber extracts have shown antidiabetic effects in a few reports. Although the triterpene glycosides of sea cucumbers are commonly isolated from their Cuvierian tubules, these are absent in Holothuria atra Jaeger. Therefore, this study intended to investigate the saponin profile in the body wall of H. atra, as well as to assess the α-glucosidase inhibitory activity of the H. atra extracts. The chemical profiling of sea cucumber extracts was conducted by UPLC-HRMS analysis. This resulted in the tentative identification of 11 compounds, 7 of which have not been reported in the H. Atra body wall before. Additionally, two triterpene glycosides were purified and their structures were elucidated based on HRMS and NMR data: desholothurin B (1), and a novel epimer, 12-epi-desholothurin B (2). Moreover, the fatty acid profile of the H. atra body wall was investigated by GC-MS. It was found that the Me90 fraction of the H. atra body wall showed the strongest α-glucosidase inhibitory activity (IC50 value 0.158 ± 0.002 mg/mL), thus making it more potent than acarbose (IC50 value 2.340 ± 0.044 mg/mL).

Can Biomarkers of Oxidative Stress in Serum Predict Disease Severity in West Nile Virus Infection? A Pilot Study.

West Nile virus (WNV) can cause asymptomatic infection in humans, result in self-limiting febrile illness, or lead to severe West Nile Neuroinvasive disease (WNND). We conducted a pilot study to compare selected biomarkers of oxidative stress in sera of viremic West Nile virus patients and asymptomatic infected blood donors to investigate their potential as predictors of disease severity. We found that total oxidant status was elevated in WNND and in uncomplicated WNV infections (median 9.05 (IQR 8.37 to 9.74) and 7.14 (7.03 to 7.25) µmol H2O2 equiv./L, respectively) compared to asymptomatic infections (0.11 (0.07 to 0.19) µmol H2O2 equiv./L) (p = 0.048). MDA levels showed a similar trend to TOS, but differences were not significant at α = 0.05. Total antioxidant status did not differ significantly between different disease severity groups. Oxidative stress appears to be associated with more severe disease in WNV-infected patients. Our preliminary findings warrant prospective studies to investigate the correlation of oxidative stress with clinical outcomes and severity of WNV infection.

Mitigation of benznidazole toxicity and oxidative stress following ascorbic acid supplementation in an adult traveller with chronic indeterminate Chagas' disease.

BACKGROUND: Benznidazole is an effective drug in the trypanocidal treatment of acute and chronic indeterminate Chagas' disease (CD). However, adverse drug reactions (ADR) are common and frequently cause patients to discontinue treatment. OBJECTIVES: We hypothesized that antioxidant supplementation could mitigate benznidazole-induced toxicity. METHODS: We co-supplemented an adult traveller with chronic indeterminate CD who experienced benznidazole ADR with ascorbic acid (AA), 1000 mg/day. We measured selected serum biomarkers of oxidative stress [total antioxidant status (TAS), total oxidative status (TOS), nuclear factor erythroid 2-related factor 2 (Nrf2), malondialdehyde (MDA), extracellular glutathione peroxidase (GPX3), catalase (CAT) and total superoxide dismutase (T-SOD)] at timepoints before and throughout benznidazole treatment and after AA co-supplementation. RESULTS: AA co-supplementation effectively mitigated benznidazole-induced ADR during the aetiological treatment of chronic indeterminate CD. The kinetics of serum biomarkers of oxidative stress suggested significantly decreased oxidative insult in our patient. CONCLUSIONS: We hypothesize that the key pathophysiological mechanism of benznidazole-associated toxicity is oxidative stress, rather than hypersensitivity. AA co-supplementation may improve adherence to benznidazole treatment of chronic indeterminate (or acute) CD. Oxidative stress biomarkers have the potential to guide the clinical management of CD. Prospective studies are needed to establish the benefit of antioxidant co-supplementation to benznidazole treatment of CD in reducing benznidazole toxicity, parasite clearance and the prevention of end-organ damage.

Magnesium, Iron, Zinc, Copper and Selenium Status in Attention-Deficit/Hyperactivity Disorder (ADHD).

In this study, we critically review the literature concerning the relation of Mg, Fe, Zn, Cu and Se and attention-deficit/hyperactivity disorder (ADHD). Elemental status is estimated using peripheral blood parameters, hair, urine, daily intake and response to supplementation. The observed associations between concentration levels of the elements Mg, Fe, Zn, Cu and Se and ADHD symptoms are contradictory. This is partly due to the heterogeneity and complexity of the disorder. As a trend, lower ferritin and zinc levels can be observed. However, this correlation is not causative, as illustrated by placebo-controlled trials reporting conflicting evidence on the efficacy of supplementation. Well-defined studies on changes in concentration levels of the elements in relation to ADHD symptoms before and after treatment with therapeutics it will be possible to shed more light on the significance of these elements in this behavioral disorder. The discussion on whether a change in concentration of an element is cause or consequence of ADHD is not within the scope of this article.

Selenium Status in Elderly People: Longevity and Age-Related Diseases.

BACKGROUND: Selenium (Se) is a trace element active in selenoproteins, which can regulate oxidative stress. It is generally perceived as an import factor for maintaining health in the elderly. METHODS: The goal of this review is to discuss selenium concentration in biological samples, primarily serum or plasma, as a function of age and its relation with longevity. The elemental level in various age-related diseases is reviewed. CONCLUSION: Highest selenium values were observed in healthy adults, while in an elderly population significantly lower concentrations were reported. Variables responsible for contradictory findings are mentioned. Risk and benefits of Se-supplementation still remain under debate.

Dietary Polyphenols Targeting Arterial Stiffness: Interplay of Contributing Mechanisms and Gut Microbiome-Related Metabolism.

Increased arterial stiffness is a degenerative vascular process, progressing with age that leads to a reduced capability of arteries to expand and contract in response to pressure changes. This progressive degeneration mainly affects the extracellular matrix of elastic arteries and causes loss of vascular elasticity. Recent studies point to significant interference of dietary polyphenols with mechanisms involved in the pathophysiology and progression of arterial stiffness. This review summarizes data from epidemiological and interventional studies on the effect of polyphenols on vascular stiffness as an illustration of current research and addresses possible etiological factors targeted by polyphenols, including pathways of vascular functionality, oxidative status, inflammation, glycation, and autophagy. Effects can either be inflicted directly by the dietary polyphenols or indirectly by metabolites originated from the host or microbial metabolic processes. The composition of the gut microbiome, therefore, determines the resulting metabolome and, as a consequence, the observed activity. On the other hand, polyphenols also influence the intestinal microbial composition, and therefore the metabolites available for interaction with relevant targets. As such, targeting the gut microbiome is another potential treatment option for arterial stiffness.

Revelation of the metabolic pathway of hederacoside C using an innovative data analysis strategy for dynamic multiclass biotransformation experiments.

Although some herbal remedies have been used for decades, little is known about the active compounds and the mechanism of action. Many natural products, such as glycosides, can be considered as prodrugs, which become active after biotransformation. To optimize the workflow of in vitro biotransformation followed by automated data analysis, hederacoside C was used as a model compound for saponins. Hederacoside C was subjected to gastrointestinal enzymes and fecal microflora. Samples were analyzed with UHPLC-PDA-HRMS before, during and after in vitro biotransformation, which allowed the monitoring of the relative abundances of the compound and its metabolites. The data-analysis workflow was optimized to render as much information as possible from the longitudinal LCMS data. XCMS was used to convert the raw data into features via peak-picking, followed by grouping, and EDGE was used for the extraction of significant differential profiles. To evaluate if the workflow was suitable for dynamic multiclass metabolomics data, an interactive Shiny web app was developed in R to rate the quality of the resulting features. These ratings were used to train a random forest model for predicting experts response. A performance analysis revealed that the random forest model was capable of correctly predicting the reviewers response in most cases (AUC 0.926 with 10 fold cross validation). The automated data analysis workflow was used for unbiased screening for metabolites and revealed the biotransformation of hederacoside C. As expected, a decrease in relative abundance of hederacoside C was observed over time. Additionally, the relative abundance of metabolites increased, illustrating the biotransformation of hederacoside C, especially in the colon phase, where microbial fermentation takes place. Stepwise progressive elimination of sugar moieties was the major metabolic pathway.

Oxidative stress and immune aberrancies in attention-deficit/hyperactivity disorder (ADHD): a case-control comparison.

The objective of this study is to compare oxidative stress and immune biomarkers between attention-deficit/hyperactivity disorder (ADHD) patients and controls without ADHD. A case-control comparison between 57 paediatric (6-12 years) untreated ADHD patients from the Antwerp University Hospital and 69 controls without ADHD from random schools in Flanders, Belgium, was conducted. Erythrocyte glutathione (GSH) and plasma lipid-soluble antioxidants (retinol, α-tocopherol, γ-tocopherol, retinyl palmitate, ß-carotene, and co-enzyme Q10) were determined by HPLC with electrochemical detection, plasma malondialdehyde (MDA) by HPLC with fluorescence detection, plasma cytokines (interleukin (IL)-1ß, IL-5, IL-6, IL-8, IL-10, tumour necrosis factor (TNF) and interferon (INF)-γ) and immunoglobulins (IgE, IgG and IgM) by flow cytometry and urinary 8-hydroxy-2'deoxyguanosine (8-OHdG) levels by ELISA assay. Dietary habits were determined by a food frequency questionnaire. Plasma MDA levels were on average 0.031 µM higher in patients than in controls (p < 0.05), and a trend for higher urinary 8-OHdG was observed. Erythrocyte GSH and plasma retinyl palmitate levels, as well as IgG and IgE levels, were higher in patients than in controls as well (on average 93.707 µg/ml, 0.006 µg/ml, 301.555 µg/ml and 125.004 µg/ml, resp., p < 0.05). Finally, a trend for lower plasma IL-5 levels was observed. After Bonferroni correction for multiple testing, the difference in GSH levels remained statistically significant (nominally significant for retinyl palmitate), while significance was lost for MDA, IgG and IgE levels. Dietary habits do not appear to cause the observed differences. These results point at the potential involvement of slight oxidative stress and immune disturbances in ADHD.

A red yeast rice-olive extract supplement reduces biomarkers of oxidative stress, OxLDL and Lp-PLA2, in subjects with metabolic syndrome: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Metabolic syndrome (MetS) refers to clustered cardiovascular risk factors (abdominal obesity, pre-diabetes, high blood pressure, dyslipidaemia). Therapies targeting oxidative stress may delay progression to atherosclerosis and diabetes. We investigated the anti-oxidative effect of a supplement combining red yeast rice and olive extract in patients with MetS. METHODS: A double-blind, placebo-controlled, randomised trial was conducted with 50 patients with MetS as defined by National Cholesterol Education Program Adult Treatment Panel III criteria. Forty-nine subjects randomly assigned to red yeast rice-olive extract (RYR-olive extract; 10.82 mg of monacolins and 9.32 mg of hydroxytyrosol per Cholesfytolplus capsule) or placebo completed the 8-week trial. Whereas effects on cardiovascular risk parameters of MetS have been reported recently, the observed significant 20% increase in oxidised low-density lipoprotein (OxLDL) prompted us to investigate other oxidative stress-related parameters: malondialdehyde (MDA), lipoprotein-associated phospholipase A2 (Lp-PLA2) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Statistical calculations included univariate quantitative analysis, multivariate linear regression and correlation analysis. RESULTS: The updated results indicate that an RYR-olive extract supplement significantly reduced Lp-PLA2 by 7% (p < 0.001), but it failed to show a significant decrease in plasma MDA and 8-OHdG (p > 0.05). Reductions in OxLDL (20%) and Lp-PLA2 (7%) were associated with each other (r = 0.740, p < 0.001). CONCLUSIONS: RYR-olive extract significantly reduced Lp-PLA2 in correlation with the marked reduction in plasma OxLDL, which may lead to a reduced risk for cardiovascular disease in patients with MetS. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02065180 . Registered on 13 February 2014.

Effect of Pycnogenol® on attention-deficit hyperactivity disorder (ADHD): study protocol for a randomised controlled trial.

BACKGROUND: Methylphenidate (MPH), the first choice medication for attention-deficit hyperactivity disorder (ADHD), is associated with serious adverse effects like arrhythmia. Evidence on the association of ADHD with immune and oxidant-antioxidant imbalances offers potential for antioxidant and/or immunomodulatory nutritional supplements as ADHD therapy. One small randomised trial in ADHD suggests, despite various limitations, therapeutic benefit from Pycnogenol®, a herbal, polyphenol-rich extract. METHODS: This phase III trial is a 10-week, randomised, double-blind, placebo and active treatment controlled multicentre trial with three parallel treatment arms to compare the effect of Pycnogenol® to MPH and placebo on the behaviour of 144 paediatric ADHD and attention-deficit disorder (ADD) patients. Evaluations of behaviour (measured by the ADHD-Rating Scale (primary endpoint) and the Social-emotional Questionnaire (SEQ)), immunity (plasma cytokine and antibody levels, white blood cell counts and faecal microbial composition), oxidative stress (erythrocyte glutathione, plasma lipid-soluble vitamins and malondialdehyde and urinary 8-OHdG levels, as well as antioxidant enzyme activity and gene expression), serum zinc and neuropeptide Y level, urinary catecholamines and physical complaints (Physical Complaints Questionnaire) will be performed in week 10 and compared to baseline. Acceptability evaluations will be based on adherence, dropouts and reports of adverse events. Dietary habits will be taken into account. DISCUSSION: This trial takes into account comorbid behavioural and physical symptoms, as well as a broad range of innovative immune and oxidative biomarkers, expected to provide fundamental knowledge on ADHD aetiology and therapy. Research on microbiota in ADHD is novel. Moreover, the active control arm is rather unseen in research on nutritional supplements, but of great importance, as patients and parents are often concerned with the side effects of MPH. TRIAL REGISTRATION: Clinicaltrials.gov number: NCT02700685 . Registered on 18 January 2016. EudraCT 2016-000215-32 . Registered on 4 October 2016.

Effect of various diets on biomarkers of the metabolic syndrome.

The impact of the normal whole diet in different countries and of special types of diet on the biomarkers of the metabolic syndrome (MetS) is reviewed. Diet type, specification, risk of MetS and studied biomarkers, as far as could be traced, are included. Critical points in published studies are mentioned. Description of the traditional dietary patterns for the various countries is not always well-defined and numbers of persons in the studied population are sometimes quite limited, which hamper drawing definite conclusions. Since a Nordic diet, a dietary approach to stop hypertension (DASH), and especially a Mediterranean diet are quite promising, due to its health claims, the food pattern is studied more in detail and a large spectrum of vegetarian diets are included as well. Most of the time lipid profile and high sensitive C-reactive protein (hsCRP) are the studied biomarkers in response to diet intake.

Study of potential systemic oxidative stress animal models for the evaluation of antioxidant activity: status of lipid peroxidation and fat-soluble antioxidants.

Although many compounds have already been tested in-vitro to determine their antioxidant profile, it is necessary to investigate the in-vivo effect of potential antioxidants. However, representative models of systemic oxidative stress have been poorly studied. Here, different potential systemic oxidative stress animal models have been investigated. These included a vitamin E-deficient rat, a diabetic rat and an atherosclerotic rabbit model. Plasma/serum malondialdehyde was measured as a parameter of oxidative damage. Plasma/serum fat-soluble antioxidants were determined as markers of antioxidant defence. We demonstrated that vitamin E-deficient rats were not suitable as a model of systemic oxidative stress, whereas diabetic and atherosclerotic animals showed increased systemic oxidative damage, as reflected by significantly augmented plasma/serum malondialdehyde. Moreover, plasma coenzyme Q9 increased by 80% in diabetic rats, confirming systemic oxidative stress. In view of these observations and economically favouring factors, the diabetic rat appeared to be the most appropriate systemic oxidative stress model. These findings have provided important information concerning systemic oxidative stress animal models for the in-vivo study of antioxidants.

Method development and validation for monitoring in vivo oxidative stress: evaluation of lipid peroxidation and fat-soluble vitamin status by HPLC in rat plasma.

Monitoring in vivo oxidative stress implicates the evaluation of damage and defence parameters by well-established, validated methods. We report two optimized and validated HPLC methods for measurement of malondialdehyde (MDA) and fat-soluble vitamins in rat plasma. For the MDA method, optimization experiments of the thiobarbituric acid test resulted in the addition of 1% butylhydroxytoluene to the reaction mixture and in a heating time reduction to 40 min, ensuring inhibition of further lipid peroxidation during the test. Validation experiments showed good linearity, precision and recovery. The use of HPLC with coulometric array detection technology permits simultaneous and sensitive analysis of different fat-soluble vitamins and related compounds (tocopherols, retinoids, carotenoids and coenzyme Q10), which are identified by both retention time and electrochemical characteristics. Furthermore, this method is extended to the analysis of coenzyme Q9, the predominant homologue in rats. Validation experiments with rat plasma gave good results.

Phytoestrogens: recent developments.

Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. Based on their chemical structure, phytoestrogens can be classified into four main groups, i. e., isoflavonoids, flavonoids, stilbenes, and lignans. For each group, the chemistry, dietary sources and biotransformation of the most interesting compounds will be discussed. Since phytoestrogens are structurally very similar to the estrogen 17beta-estradiol, they may exhibit selective estrogen receptor modulating activities. Therefore, special attention will be given to the hormonal effects of various isoflavonoids, including genistein, daidzein, coumestrol and equol, several prenylated flavonoids, especially 8-prenylnaringenin, and the stilbene resveratrol. Furthermore, their non-hormonal effects will be discussed briefly. Finally, the latest developments on the potential protective properties of phytoestrogens and phytoestrogen-containing foods against hormone-dependent breast and prostate cancers and cardiovascular diseases, and as estrogen replacement therapy for postmenopausal women will be discussed.

Anticomplement and antioxidant activities of new acetylated flavonoid glycosides from Centaurium spicatum.

In addition to the three acetylated flavonol glycosides, quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-beta-galactopyranoside, quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-3-acetyl-beta-galactopyranoside, and quercetin 3- O-[(2,3,4- triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-4-acetyl-beta-galactopyranoside, which have recently been isolated from Centaurium spicatum (L.) Fritsch (Gentianaceae), a new pentaacetylated flavonoid glycoside was isolated from the same plant. Structure elucidation, especially the localization of the acetyl groups, and complete (1)H- and (13)C-NMR assignments, was carried out using one- and two-dimensional NMR methods, including (1)H- and (13)C-NMR, DEPT-135 and DEPT-90, and gradient-assisted experiments such as DQF-COSY, TOCSY, HSQC and HMBC. The structure of the new flavonoid glycoside was established as quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-3,4-diacetyl-beta-galactopyranoside. The anticomplement and antioxidant activities of these compounds were evaluated. The triacetylated flavonoid glycoside showed the highest activity in the two assays.

In vitro inhibition of [3H]-angiotensin II binding on the human AT1 receptor by proanthocyanidins from Guazuma ulmifolia bark.

A bioassay-guided fractionation of the 70% acetone extract of the bark of Guazuma ulmifolia Lam. on the inhibition of angiotensin II binding to the AT 1 receptor led to the isolation and identification of bioactive oligomeric and polymeric proanthocyanidins consisting mainly of (-)-epicatechin units. The displacement of [3H]-angiotensin II binding was dose-dependent and correlated with the degree of polymerization of the different fractions containing proanthocyanidins. A strong displacement was seen for the residual fraction suggesting that the most active substances corresponding to the highly polymerized proanthocyanidins. Angiotensin II AT 1 receptor binding might be considered as a potentially interesting biological activity of proanthocyanidins contributing to the very broad spectrum of biological activities of the condensed tannins.

Antiviral and antioxidant activity of flavonoids and proanthocyanidins from Crataegus sinaica.

The antiviral and antioxidant activity of some fractions and of a series of flavonoids and proanthocyanidins obtained from Crataegus sinaica (Rosaceae) was evaluated. The O-glycosidic flavonoids and the oligomeric proanthocyanidins exhibited significant inhibitory activity against herpes simplex virus type 1 (HSV-1), which was shown to be due to an extracellular mechanism for procyanidin C-1. Procyanidin C-1 also had the highest antioxidant activity in both the microsomal lipid peroxidation and the hydroxyl radical scavenging assay. In addition to the previously reported phenolic compounds, the pentacyclic triterpenoid ursolic acid (1) and a tetrameric (2) and pentameric procyanidin (3) are reported for the first time.