Person: León González, María Eugenia De
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First Name
María Eugenia De
Last Name
León González
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
29 results
Search Results
Now showing 1 - 10 of 29
Item A Comprehensive Analytical Review of Polyphenols: Evaluating Neuroprotection in Alzheimer’s Disease(International Journal of Molecular Sciences, 2024) Vicente Zurdo, David; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia DeAlzheimer’s Disease (AD), a prevalent neurodegenerative disorder, is the primary cause of dementia. Despite significant advancements in neuroscience, a definitive cure or treatment for this debilitating disease remains elusive. A notable characteristic of AD is oxidative stress, which has been identified as a potential therapeutic target. Polyphenols, secondary metabolites of plant origin, have attracted attention due to their potent antioxidant properties. Epidemiological studies suggest a correlation between the consumption of polyphenol-rich foods and the prevention of chronic diseases, including neurodegenerative disorders, which underscores the potential of polyphenols as a therapeutic strategy in AD management. Hence, this comprehensive review focuses on the diverse roles of polyphenols in AD, with a particular emphasis on neuroprotective potential. Scopus, ScienceDirect, and Google Scholar were used as leading databases for study selection, from 2018 to late March 2024. Analytical chemistry serves as a crucial tool for characterizing polyphenols, with a nuanced exploration of their extraction methods from various sources, often employing chemometric techniques for a holistic interpretation of the advances in this field. Moreover, this review examines current in vitro and in vivo research, aiming to enhance the understanding of polyphenols’ role in AD, and providing valuable insights for forthcoming approaches in this context.Item Effect of Storage and Drying Treatments on Antioxidant Activity and Phenolic Composition of Lemon and Clementine Peel Extracts(Molecules, 2023) Gómez Mejía, Esther; Sacristán Navarro, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaObtaining polyphenols from horticultural waste is an emerging trend that enables the valorization of resources and the recovery of value-added compounds. However, a pivotal point in the exploitation of these natural extracts is the assessment of their chemical stability. Hence, this study evaluates the effect of temperature storage (20 and −20 ◦C) and drying methods on the phenolic composition and antioxidant activity of clementine and lemon peel extracts, applying HPLC-DADMS, spectrophotometric methods, and chemometric tools. Vacuum-drying treatment at 60 ◦C proved to be rather suitable for retaining the highest antioxidant activity and the hesperidin, ferulic, and coumaric contents in clementine peel extracts. Lemon extracts showed an increase in phenolic acids after oven-drying at 40 ◦C, while hesperidin and rutin were sustained better at 60 ◦C. Hydroethanolic extracts stored for 90 days preserved antioxidant activity and showed an increase in the total phenolic and flavonoid contents in lemon peels, unlike in clementine peels. Additionally, more than 50% of the initial concentration was maintained up to 51 days, highlighting a half-life time of 71 days for hesperidin in lemon peels. Temperature was not significant in the preservation of the polyphenols evaluated, except for in rutin and gallic acid, thus, the extracts could be kept at 20 ◦C.Item Cytotoxicity, uptake and accumulation of selenium nanoparticles and other selenium species in neuroblastoma cell lines related to Alzheimer’s disease by using cytotoxicity assays, TEM and single cell-ICP-MS(Analytica Chimica Acta, 2023) Vicente Zurdo, David; Gómez Gómez, Beatriz; Romero Sánchez, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda; Elsevier B.V.Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease, representing 80% of the total dementia cases. The “amyloid cascade hypothesis” stablishes that the aggregation of the beta-amyloid protein (Aβ42) is the first event that subsequently triggers AD development. Selenium nanoparticles stabilized with chitosan (Ch-SeNPs) have demonstrated excellent anti-amyloidogenic properties in previous works, leading to an improvement of AD aetiology. Here, the in vitro effect of selenium species in AD model cell line has been study to obtain a better assessment of their effects in AD treatment. For this purpose, mouse neuroblastoma (Neuro-2a) and human neuroblastoma (SH-SY5Y) cell lines were used. Cytotoxicity of selenium species, such as selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys) and Ch-SeNPs, has been determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry methods. Intracellular localisation of Ch-SeNPs, and their pathway through SH-SY5Y cell line, have been evaluated by transmission electron microscopy (TEM). The uptake and accumulation of selenium species by both neuroblastoma cell lines have been quantified at single cell level by single cell- Inductively Coupled Plasma with Mass Spectrometry detection (SCICP-MS), with a previous optimisation of transport efficiency using gold nanoparticles (AuNPs) ((69 ± 3) %) and 2.5 mm calibration beads ((92 ± 8) %). Results showed that Ch-SeNPs would be more readily accumulated by both cell lines than organic species being accumulation ranges between 1.2 and 89.5 fg Se cell 1 for Neuro-2a and 3.1–129.8 fg Se cell1 for SH-SY5Y exposed to 250 μM Ch-SeNPs. Data obtained were statistically using chemometric tools. These results provide an important insight into the interaction of Ch-SeNPs with neuronal cells, which could support their potential use in AD treatment.Item Valorization of defatted cherry seed residues from Liquor processing by matrix solid-phase dispersion extraction: a sustainable strategy for production of phenolic-rich extracts with antioxidant potential(Antioxidants, 2023) Rodríguez-Blázquez, Sandra; Fernández-Ávila, Lorena; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Miranda Carreño, RubénThe integrated valorization of food chain waste is one of the most promising alternatives in the transition to a sustainable bioeconomy. Thus, an efficient solid-phase matrix dispersion extraction method, using experimental factorial design and response surface methodology, has been developed and optimized for the recovery of polyphenols from defatted cherry seeds obtained after cherry liquor manufacture and subsequent fatty acid extraction, evaluating the effect of each processing step on the composition and phenolic content of sweet cherry residues. The phenolic extracts before fermentation showed the highest content of total polyphenols (TPC) and flavonoids (TFC) (3 ± 1 mg QE·g−1 and 1.37 ± 0.08 mg GAE·g−1, respectively), while the highest antioxidant capacity was obtained in the defatted seed extracts after both fermentation and distillation. In addition, high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS) was used to determine the phenolic profile. Dihydroxybenzoic acid, neochlorogenic acid, caffeic acid, and quercetin were the main phenolics found, showing differences in concentration between the stages of liquor production. The results underline the prospective of cherry by-products for obtaining phenol-rich bioactive extracts for possible use in different industrial sectors, offering a feasible solution for the cascade valorization of cherry agri-food waste.Item Ability of selenium species to inhibit metal-induced Aβ aggregation involved in the development of Alzheimer’s disease(Analytical and Bioanalytical Chemistry, 2020) Vicente Zurdo, David; Romero Sánchez, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda; Springer HeidelbergExtracellular accumulation of amyloid beta peptide (Aβ) is believed to be one of the main factors responsible for neurodegeneration in Alzheimer’s disease (AD). Metals could induce Aβ aggregation, by their redox activity or binding properties to amyloid β fibrils, leading to their accumulation and deposition outside neurons. For this reason, metal chelation may have an acknowledged part to play in AD prevention and treatment. In the current work, the role of different selenium species, including selenium nanoparticles, in Aβ aggregation, was studied by evaluating their metal-chelating properties and their ability both to inhibit metal-induced Aβ1–42 aggregation fibrils and to disaggregate them once formed. Transition biometals such as Fe(II), Cu(II), and Zn(II) at 50 μM were selected to establish the in vitro models. The DPPH assay was used to determine the antioxidant capacity of the evaluated selenium species. Selenium nanoparticles stabilized with chitosan (Ch-SeNPs) and with both chitosan and chlorogenic acid polyphenol (CGA@ChSeNPs) showed the highest antioxidant properties with EC50 of 0.9 and 0.07 mM, respectively. UV–Vis and d1(UV–Vis) spectra also revealed that selenium species, in particular selenomethionine (SeMet), were able to interact with metals. Regarding Aβ1–42 incubation experiments, Fe(II), Cu(II), and Zn(II) induced Aβ aggregation, in a similar way to most of the evaluated selenium species. However, Ch-SeNPs produced a high inhibition of metal-induced Aβ aggregation, as well as a high disaggregation capacity of Aβ fibrils in both the presence and absence of biometals, in addition to reducing the length and width (20% of reduction in the presence of Zn(II)) of the generated Aβ fibrils.Item Simultaneous determination of the size and concentration of AgNPs in water samples by UV–vis spectrophotometry and chemometrics tools(Talanta, 2018) Moreno Martín, Gustavo; León González, María Eugenia De; Madrid Albarrán, María YolandaThe combination of UV–vis spectrophotometry with a chemometric calibration tool based on partial least squares (PLS) has allowed us the development of a multivariate analytical method that simultaneously estimates the concentration and size of mixtures of silver nanoparticles (AgNPs) in environmental water samples. The method is based on changes in the surface plasmon resonance band (SPRB) of AgNPs when they form aggregated/assembled structures with L-cysteine (L-cys). Measurementts were performed by employed a fixed-time kinetics method that implies that the final spectra (response) are obtained by subtstracting the solutions spectra at fixed times. Optimization of experimental conditions affecting aggregation such as time, temperature, pH and concentration of aggregating substance was performed by experimental design and response surface methodologies (RSM). A multivariate calibration model using AgNPs of known diameter size ((20 ± 3), (41 ± 3), (59 ± 5) and (79 ± 7) nm) within a concentration range between 0.62 and 2.5 mg L−1 was constructed by using a mixture experimental design and PLS. The method was finally applied to estimate size and concentration of AgNPs in AgNPs-spiked river and tap water samples. Water samples were spiked with individual, binary and ternary mixtures of AgNPs of different sizes and by using two types of AgNPs: citrate-coated AgNPs (cit-AgNPs) and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). A good correspondence was obtained between predicted values and the total amount of AgNPs added with recovery values ranged within 80–160% for the individual mixtures, 68–108% for the binary mixtures and 60–64% for the ternary mixtures of AgNPs. Finally, transmission electron microscopy (TEM) measurements were performed for those cases where discrepancies between the expected and the obtained values were observed. TEM micrographs evidenced the presence of agglomerates or aggregates of AgNPs in some of the mixtures or water tested.Item Anti-inflammatory activity of ethyl acetate and n-butanol extracts from Ranunculus macrophyllus Desf. and their phenolic profile(Journal of Ethnopharmacology, 2021) Deghima, Amirouche ; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, FatihaEthnopharmacological relevance: The members of the genus Ranunculus have counter-irritating properties and thus, they are traditionally used for treating anti-inflammatory disorders and other skin conditions. Ranunculus macrophyllus Desf. is a wild medicinal plant growing in Algeria and traditionally used to treat some cutaneous skin disorders. Aim: The aim of this study was to characterize the composition of the ethyl acetate and n-butanol extracts from Ranunculus macrophyllus Desf. as well as to elucidate and to compare their effect against acute skin inflammation. Moreover, both the antioxidant activity and the acute toxicity of the plant extracts were also studied. Materials and methods: Spectrophotometric and chromatographic methods were employed to identify and quantify phenolic compounds and triterpenoids from R. macrophyllus Desf. fractions. The antioxidant activity was estimated using the phosphomolebdenum, DPPH, reducing power and β-carotene bleaching assays. The ethyl acetate and n-butanol extracts were screened for their anti-inflammatory activities using ex-vivo membrane stabilizing assays and in-vivo acute skin inflammation model. Results: Ethyl acetate fraction showed the highest amounts of total phenolic compounds (413 ± 4 μg GAE/mg extract) and triterpenoids (70.4 ± 1.8 μg UAE/mg extract). Rutin, hesperidin, myricetin and kaempferol were the major compounds identified in the different fractions. Ethyl acetate fraction exhibited strong DPPH• radical scavenging ability (IC50 1.6 ± 0.2 μg/mL), high total antioxidant capacity (447 ± 7 μg AAE/mg extract) and reducing power (514 ± 8 μg AAE/mg extract). Ethyl acetate fraction inhibited (73.4 ± 0.3) % of linoleic acid peroxidation. Ethyl acetate and n-butanol fractions did not have any visible toxicity at 2000 mg/kg and presented excellent membrane stabilizing ability. The inhibition of xylene induced ear inflammation was (38 ± 4) % and (46 ± 1) % for RM-B and RM-EA, respectively. Conclusions: The high content of both phenolic compounds and triterpenoids combined with the remarkable antiinflammatory effect and antioxidant activity of ethyl acetate and n-butanol extracts from R. macrophyllus Desf. support the wide spread use of this traditional plant on some skin disorders (inflammatory skin disorders).Item Evaluation of the transformation of selenite and selenium nanoparticles to seleno-amino acids produced by Escherichia coli and Staphylococcus aureus by using liquid chromatography -inductively coupled plasma mass spectrometry and single-particle- inductively coupled plasma mass spectrometry and different sample treatments(Spectrochimica Acta Part B: Atomic Spectroscopy, 2023) Moreno Martín, Gustavo; Espada-Bernabé, Elena; Gómez Gómez, Beatriz; León González, María Eugenia De; Madrid Albarrán, María YolandaDue to the scarce knowledge about the impact of selenium nanoparticles (SeNPs) on bacterial populations, the main objective of this work was focused on evaluating the transformations of SeNPs and selenite in Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). For this purpose, an analytical methodology based on bacteria cell wall disruption, carbamidomethylation, enzymatic hydrolysis and high-performance liquid chromatography couple to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and HPLC- electrospray tandem mass spectrometry (HPLC-ESI-MS/MS) measurements was developed, the latter for unambiguous identification of selenium species. Once bacteria were cultured in the presence of chitosan modified SeNPs (Ch-SeNPs) and selenite at 0, 1 and 2 mg L 1 Se for 24 h, an enzymatic disruption of the bacterial cell wall using lysozym followed by enzymatic hydrolysis with protease was applied. The use of lysozyme to extract selenium speciesprovided a better efficiency in the total selenium content (higher than 96%), compared to a mechanical disruption of the bacterial cell wall. Analysis of the extracts by anionic exchange HPLC-ICP-MS showed a strong influence of incubation time with protease (24, 48 and 72 h) on selenium chromatographic profile. The results showed that selenocysteine (SeCys) was the only Se species identified in both bacteria representing an 80% of total selenium accumulated. The confirmation of the identity of this Se species was carried out after performing a carbamidomethylation process, prior to enzymatic hydrolysis, and analyzing the extract by reversed phase HPLCESI- MS/MS. These analyses confirmed the presence of SeCys, and no relevant differences were found between the metabolic pathway of both forms of selenium. Moreover, the growth of both bacterial species in the presence of selenite resulted in the formation of biogenic SeNPs. Characterization by TEM before and after their separation from the culture medium showed spherical and monodispersed nanoparticles with an average size (155 ± 19) nm and (172 ± 20) nm for E. coli and S. aureus, respectively. Analysis by spICP-MS showed no significant differences in size with respect to TEM after considering the ionization efficiency of Se.Item In-vivo solid phase microextraction for quantitative analysis of volatile organoselenium compounds in plants(Analytica Chimica Acta, 2019) Moreno Martín, Gustavo; Sanz Landaluce, Jon; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ElsevierA new calibration method based on the use of headspace solid-phase microextraction (HS-SPME) and in-fiber internal standardization, combined with gas chromatography coupled to mass spectrometry (GC/MS) was developed for quantifying Se volatile organic species released by plants exposed to chitosan-modified selenium nanoparticles (Cs-SeNPs). The effect of several parameters affecting extraction and separation of the selected organic species of selenium (dimethylselenium (DMSe), diethylselenium (DESe) and dimethyldiselenium (DMDSe)) and deuterated dimethyl sulphide (d6-DMS) employed as internal standard were studied and optimized using an experimental design. The developed methodology was applied for quantifying the volatile selenium compounds produced over time by the plant species Raphanus sativus and Brassica juncea grown in hydroponic solution containing 5 mg Se L−1 in the form Cs-SeNPs. The procedure employed consisted in two steps. Volatile selenium species released from the plants were first extracted in the SPME fiber located at the headspace of a box with a fixed volume. Subsequently, the internal standard placed in a vial subjected to the same conditions as plants was extracted on the same fiber than the one previously used for extracting selenium compounds. Finally the extracted compounds were separated and analyzed by GC/MS. Results evidenced Cs-SeNPs biotransformation into DMSe and DMDSe by both plants species during growing stage, in amounts of the order of ng. Additionally, the resulting data were submitted to multifactorial ANOVA to evaluate the influence of plant type and time of exposure to Cs-SeNPs on the production of volatile selenium compounds.Item Valorisation of the green waste parts from large-leaved buttercup (Ranunculus macrophyllus Desf.): phenolic profile and health promoting effects study(Waste and biomass valorization, 2020) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, Fatiha; SpringerDue to the extensive use of Ranunculus macrophyllus Desf. roots for medicinal purposes, most of the leafy green parts are just wasted. The aim of this work is to valorize the leafy green parts and promote their application in different modern industries. Methods For this purpose, we studied the phenolic profile of R. macrophyllus Desf. (RM-B) using chromatographic and spectrophotometric methods and we tested the in-vitro antioxidant activity and the in-vivo effect of RM-B on plasma and liver antioxidant statuts. Results RM-B contained high amounts of polyphenols (675 mg GAE/100 g dry weigh dw) and flavonoids (105 mg QE/100 g dw). In-vitro, RM-B exhibited promising radical scavenging activity against 2,2′-azino-bis(3-éthylbenzothiazoline-6-sulphonique) (ABTS+·) (IC50: 247 µg/mL), hydrogen peroxide radicals (IC50: 626 µg/mL) and inhibited oxidative red blood cells hemolysis (IC50: 120 µg/mL), RM-B also showed strong reducing power (982 µM FeSO4/mg extract). In-vivo, RM-B improved the radical scavenging ability and reducing power of plasma and enhanced liver antioxidant status by increasing catalase and reduced glutathione levels and decreasing malondialdhyde levels without altering the key serum biochemical parameters reflecting liver and kidney functions. Polyphenols identified using capillary LC-DAD and LC–MS/MS analyses like hesperidin (131.2 mg/100 g dw), rutin (29.0 mg/100 g dw) and p-coumaric acid (5.8 mg/100 g dw), may be responsible for the health promoting effects of RM-B. Conclusion We may conclude that R. macrophyllus Desf. is a good source of beneficial polyphenols with strong antioxidant, anti-hemolytic and health-promoting effects, which promotes its use in pharmaceutical, medicinal and nutraceutical industries.
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