Irigoyen, A. (Angel)

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    Levels of ochratoxins in Mediterranean red wines
    (Elsevier, 2013) Remiro, R. (Rebeca); Lopez-de-Cerain, A. (Adela); Gonzalez-Peñas, E. (Elena); Irigoyen, A. (Angel); Lizarraga, E. (Elena)
    The co-occurrence of ochratoxin A (OTA) and its five analogs (OTB, OTC, MeOTA, MeOTB and EtOTB) in 96 red wine samples from Mediterranean countries has been demonstrated, for the first time, in this study. OTA was detected in 99 % of the samples (
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    Influence of culinary process on free and bound (poly)phenolic compounds and antioxidant capacity of artichoke
    (Elsevier, 2021) Ludwig, I.A. (Iziar Amaia); Cid, C. (Concepción); Dominguez-Fernandez, M. (Maite); Irigoyen, A. (Angel); De-Peña, M.P. (María Paz); Vargas, A. (Angelina)
    Artichokes are an important source of (poly)phenolic compounds, mainly caffeoylquinic acids, which consumption has been associated with health benefits. However, heat treatments have shown to affect the amounts of these bioactive food compounds. In the present study the influence of culinary techniques (boiling, griddling, and frying) on the total (poly)phenolic content of artichokes (Cynara Scolymus cv. Blanca de Tudela) was evaluated by LC-MS/MS. Additionally, the antioxidant capacity of cooked artichokes was evaluated by spectrophotometric methods. A total of 31 (poly)phenols were identified and quantified, being caffeoylquinic acids the most abundant compounds in raw artichokes accounting for more than 95% of total (poly)phenolic compounds. With the different culinary techniques, these compounds suffered degradation but also redistribution, probably due to isomerization and hydrolysis reactions. Frying and griddling showed the lowest content of (poly)phenolic compounds and antioxidant capacity suggesting thermal degradation. Boiling also provoked losses, which were mainly due to leaching of phenolic compounds into the water. However, it was the heat treatment that best preserved (poly)phenolic compounds in artichokes.
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    2-Hydroxy-Docosahexaenoic Acid Is Converted Into Heneicosapentaenoic Acid via α-Oxidation: Implications for Alzheimer’s Disease Therapy
    (Frontiers in Cell and Developmental Biology, 2020) Lladó, V. (Victoria); Busquets, X. (Xavier); Cabot, J. (Joan); Escribá, P.V. (Pablo V.); Parets, S. (Sebastià); Fernández-García, P. (Paula); Miralles, M. (Marc); Irigoyen, A. (Angel); Balogh, G. (Gábor); Torres, M. (Manuel); Péter, M. (Maria); Ordinas, M. (Margarita); Arbona, L. (Laura)
    Alzheimer’s disease (AD) is a neurodegenerative disease with as yet no efficient therapies, the pathophysiology of which is still largely unclear. Many drugs and therapies have been designed and developed in the past decade to stop or slow down this neurodegenerative process, although none has successfully terminated a phase-III clinical trial in humans. Most therapies have been inspired by the amyloid cascade hypothesis, which has more recently come under question due to the almost complete failure of clinical trials of anti-amyloid/tau therapies to date. To shift the perspective for the design of new AD therapies, membrane lipid therapy has been tested, which assumes that brain lipid alterations lie upstream in the pathophysiology of AD. A hydroxylated derivative of docosahexaenoic acid was used, 2-hydroxydocosahexaenoic acid (DHA-H), which has been tested in a number of animal models and has shown efficacy against hallmarks of AD pathology. Here, for the first time, DHA-H is shown to undergo α-oxidation to generate the heneicosapentaenoic acid (HPA, C21:5, n-3) metabolite, an odd-chain omega-3 polyunsaturated fatty acid that accumulates in cell cultures, mouse blood plasma and brain tissue upon DHA-H treatment, reaching higher concentrations than those of DHA-H itself. Interestingly, DHA-H does not share metabolic routes with its natural analog DHA (C22:6, n-3) but rather, DHA-H and DHA accumulate distinctly, both having different effects on cell fatty acid composition. This is partly explained because DHA-H α-hydroxyl group provokes steric hindrance on fatty acid carbon 1, which in turn leads to diminished incorporation into cell lipids and accumulation as free fatty acid in cell membranes. Finally, DHA-H administration to mice elevated the brain HPA levels, which was directly and positively correlated with cognitive spatial scores in AD mice, apparently in the absence of DHA-H and without any significant change in brain DHA levels. Thus, the evidence presented in this work suggest that the metabolic conversion of DHA-H into HPA could represent a key event in the therapeutic effects of DHA-H against AD.
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    Presence of 19 mycotoxins in human plasma in a region of Northern Spain
    (MDPI, 2020) López, B. (Beatriz); Gonzalez-Peñas, E. (Elena); Irigoyen, A. (Angel); Lizarraga, E. (Elena)
    This study was conducted to investigate human exposure to19 compounds(mycotoxins and their metabolites) in plasma samples from healthy adults (n = 438, aged 19–68 years) from Navarra, a region of northern Spain. Samples were analyzed by LC-MS/MS, before and after enzymatic hydrolysis for the detection of possible glucuronides and/or sulfates (Phase II metabolites). The most prevalent mycotoxin was ochratoxin A (OTA), with an incidence of 97.3%. Positive samples were in the concentration range of 0.4 ng/mL to 45.7 ng/mL. After enzymatic treatment, OTA levels increased in a percentage of individuals, which may indicate the presence of OTA-conjugates. Regarding ochratoxinB, ithasalso been detected(10% of the samples),and its presence may be related to human metabolism of OTA. Sterigmatocystin was detected with a high incidence (85.8%), but only after enzymatichydrolysis,supporting glucuronidationasa pathway of its metabolism in humans. None of the other studied mycotoxins (aflatoxins B1, B2, G1, G2 and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol) were detected in any of the samples,neither before nor after enzymatic treatment. To the best of our knowledge, this is the first report carried out in Spain to determine the exposure of the population to mycotoxins and some of their metabolites using plasma, and the obtained results justify the need for human biomonitoring and metabolism studies on mycotoxins.
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    Assessment of total (free and bound) phenolic compounds in spent coffee extracts
    (American Chemical Society, 2015) Ludwig, I.A. (Iziar Amaia); Cid, C. (Concepción); Peña, M.P. (María Paz) de; Monente, C. (Carmen); Irigoyen, A. (Angel)
    Spent coffee is the main byproduct of the brewing process and a potential source of bioactive compounds, mainly phenolic acids easily extracted with water. Free and bound caffeoylquinic (3-CQA, 4-CQA, 5-CQA), dicaffeoylquinic (3,4-diCQA, 3,5-diCQA, 4,5-diCQA), caffeic, ferulic, p-coumaric, sinapic, and 4-hydroxybenzoic acids were measured by HPLC, after the application of three treatments (alkaline, acid, saline) to spent coffee extracts. Around 2-fold higher content of total phenolics has been estimated in comparison to free compounds. Phenolic compounds with one or more caffeic acid molecules were approximately 54% linked to macromolecules such as melanoidins, mainly by noncovalent interactions (up to 81% of bound phenolic compounds). The rest of the quantitated phenolic acids were mainly attached to other structures by covalent bonds (62-97% of total bound compounds). Alkaline hydrolysis and saline treatment were suitable to estimate total bound and ionically bound phenolic acids, respectively, whereas acid hydrolysis is an inadequate method to quantitate coffee phenolic acids.
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    Development and validation of a methodology based on Captiva EMR-lipid clean-up and LC-MS/MS analysis for the simultaneous determination of mycotoxins in human plasma
    (Elsevier, 2020) López, B. (Beatriz); Flores-Flores, M.E. (Myra Evelyn); Gonzalez-Peñas, E. (Elena); Irigoyen, A. (Angel); Lizarraga, E. (Elena)
    We report the methodology for the quantification of 19 mycotoxins in human plasma using high performance liquid chromatography-mass spectrometry (triple quadrupole). The studied mycotoxins were: deepoxy-deoxynivalenol, aflatoxins (B1, B2, G1, G2 and M1), T-2 and HT-2, ochratoxins A and B, zearalenone, sterigmatocystin, nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, diacetoxyscirpenol and fusarenon-X. Sample deproteinization and cleanup were performed in one step using Captiva EMR-lipid (3 mL) cartridges and acetonitrile (with 1% formic acid). The extraction step was simple and fast. Validation was based on the evaluation of limits of detection (LOD) and quantification, linearity, precision, recovery, matrix effect, and stability. LOD values ranged from 0.04 ng/mL for aflatoxin B1 to 2.7 ng/mL for HT-2, except for nivalenol, which was 9.1 ng/mL. Recovery was obtained in intermediate precision conditions and at three concentration levels. Mean values ranged from 68.8% for sterigmatocystin to 97.6% for diacetoxyscirpenol (RDS ≤ 15% for all the mycotoxins). Matrix effects (assessed at three concentration levels and in intermediate conditions) were not significant for most of the mycotoxins and were between 75.4% for sterigmatocystin and 109.3% for ochratoxin B (RDS ≤ 15% for all the mycotoxins). This methodology will be useful in human biomonitoring studies of mycotoxins for its reliability.