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
14 results
Search Results
Now showing 1 - 10 of 14
Item Insights into the accumulation and transformation of Ch-SeNPs by Raphanus sativus and Brassica juncea: effect on essential elements uptake(Science of the Total Environment, 2020) Moreno Martín, Gustavo; Sanz Landaluce, Jon; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ElsevierSelenium (Se) at very low doses has important functions for humans. Unfortunately, the low levels of Se in soils in various regions of the world have implemented the agronomic biofortification of crops by applying Se-enriched fertilizers (mainly based on selenate). Lately, the use of nanofertilizers is growing in interest as their low size reduces the amount of chemicals and minimizes nutrient losses in comparison with conventional bulk fertilizers. However, the knowledge on their fate and environmental impact is still scarce. This study aims to evaluate the biotransformation of chitosan-modified Se nanoparticles (Ch-SeNPs) as well as their effect on the metabolism of essential metals (Fe, Cu, Zn and Mo) when applied to hydroponic cultivation of R. sativus and B. juncea. In house-synthesized Ch-SeNPs were characterized in both synthesis and hydroponic culture media by transmission electron microscopy (TEM), dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The composition of one-tenth strength Hoagland's solution did not affect the size, shape and concentration in number of particles per mL of Ch-SeNPs. The plants were grown inside a box at 25 °C during the months of May–July in 2018. After a week of treatment with Ch-SeNPs, plants were harvested and divided into roots and aerial part. The biotransformation of Ch-SeNPs was evaluated through a process of enzymatic hydrolysis and subsequent analysis by HPLC-ICP-MS and HPLC-ESI-MS/MS. The results confirmed the transformation of Ch-SeNPs to seleno-amino acids: Selenomethionine (SeMet), Semethylselenocysteine (SeMetSeCys) and ɣ-glutamyl-Se-MetSeCys. Moreover, Multiple-way analysis of variance (ANOVA) and principal component analysis (PCA) showed that, regardless the plant species, Ch-SeNPs supplementation affected the absorption of Zn.Item Characterization of AgNPs and AuNPs in sewage sludge by single particle inductively coupled plasma-mass spectrometry(Talanta, 2022) Moreno Martín, Gustavo; Gómez Gómez, Beatriz; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ElsevierThis study develops for the first time an analytical method for the characterization of silver and gold nanoparticles in sewage sludge. The evaluation of the effect of temperature, extracting agent and centrifugation speed and time on the extraction yield was carried out through a multifactorial analysis of variance which allows us to select 289 g, 5 min and 20 mM sodium pyrophosphate tetrabasic as optimal extraction conditions. Under these conditions, the analysis of the extract by single particle inductively coupled plasma-mass spectrometry provided recovery percentages of 70 ± 2% and 56 ± 1% for silver and gold nanoparticles, respectively. Moreover, the complementary results obtained upon analysis of these extracts by transmission electron microscopy and single particle inductively coupled plasma-mass spectrometry showed that the developed method did not modify the original size and shape of these nanoparticles during the extraction procedure. Size detection limits of 23 nm and 16 nm as well as number concentration limits of 3.12 × 109 particles kg−1 and 1.38 × 109 particles kg−1 were obtained for silver and gold nanoparticles, respectively. Moreover, a stability study of silver and gold nanoparticles in sewage sludge for 12 months showed differences between the two nanoparticle types. Although the sizes were not affected during the 12 months, silver nanoparticles underwent an oxidation process from 6 months onwards, which was reflected in an increase in the percentage of ionic silver from 14 ± 1% at 6 months to 24 ± 2% at 12 months. The developed methodology represents a simple, reliable and fast tool for detecting, quantifying and assessing the stability of nanoparticles in an important environmental sample such as sewage sludge.Item Valorization of citrus reticulata blanco peels to produce enriched wheat bread: phenolic bioaccessibility and antioxidant potential(ANTIOXIDANTS, 2023) Gómez Mejía, Esther; Sacristán, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaThe fortification of foods with bioactive polyphenols aims to improve their functional properties and to provide health benefits. Yet, to exert their benefits, phenolic compounds must be released from the food matrix and absorbed by the small intestine after digestion, so assessing their bioaccessibility is crucial to determine their potential role. This work aims to incorporate Citrus reticulata Blanco peel extracts into wheat bread as a promising opportunity to increase their bioactive potential, along with supporting the sustainable management of citrus-industry waste. A control and a wheat bread enriched at 2% and 4% (w/v) with a phenolic extract from mandarin peels were prepared and analyzed for antioxidant activity and phenolic composition using LC-MS and UV-Vis spectrophotometry. In addition, in vitro digestion was performed, and the digested extracts were analyzed with HPLC-MS/MS. The results showed a significant increase in total flavonoid content (TFC, 2.2 ± 0.1 mg·g−1), antioxidant activity (IC50 = 37 ± 4 mg·g−1), and contents of quercetin, caffeic acid, and hesperidin in the 4% (w/v) enriched bread. Yet, most polyphenols were completely degraded after the in vitro digestion process, barring hesperidin (159 ± 36 μg·g−1), highlighting the contribution of citrus enrichment in the development of an enriched bread with antioxidant potential.Item Phenolic profile, safety, antioxidant and anti-inflammatory activities of wasted Bunium ferulaceum Sm. aerial parts(Food Research International, 2022) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, Fatiha; ELSEVIERThe pharmaceutical and nutraceutical industries benefit greatly from recycling and transforming non-utilized parts of medicinal plants from agro-industrial operations into value added products. Hence, the aim of this work was to study the potential nutraceutical and pharmaceutical applications of Bunium ferulaceum Sm. aerial parts, in order to maximize their value. The phenolic profile of their hydromethanolic extract was determined and its antioxidant activity was evaluated in vitro and in vivo alongside with its anti-inflammatory activity and safety profile. The extract exerted an in vitro antioxidant activity mainly through radical scavenging (DPPH IC50: 14.0 ± 0.3 μg/ml) and iron chelating ability (24 ± 2 μg/ml), while, in vivo, the extract did not cause any mortality or visible signs of acute toxicity at high dose (2000 mg/kg body weight). The supplementation of the extract at different doses improved mice liver redox state by increasing catalase and reduced glutathione levels and reducing lipid peroxidation, without causing any toxicity. Moreover, the extract efficiently inhibited xylene induced ear inflammation (62 %). These different bioactivities were linked to the phenolic compounds present in the extract, particularly, chlorogenic acid (78 ± 6 mg/g extract), rutin (44 ± 2 mg/g extract) and hesperidin (56 ± 9 mg/g extract). However, further studies should be carried out on the isolated major compounds found in the extract to correlate the activity with these compounds or their mixture. The wasted aerial parts of Bunium ferulaceum Sm. proved to be a valuable source of polyphenols and exhibited interesting health promoting effects with no toxicity. Thus, Bunium ferulaceum Sm. aerial parts can be included in nutraceutical formulations or used as functional food and the extracted compounds may be used as an alternative food preservative.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 Bioactive polyphenols from Ranunculus macrophyllus Desf. Roots: quantification, identification and antioxidant activity(South African Journal of Botany, 2020) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Baali, Faiza; Bedjou, FatihaRanunculus macrophyllus Desf. is an Algerian medicinal plant whose roots are used in traditional medicine to cure feminine infertility and other diseases, however there are no studies regarding its phytochemistry and biological activities. The aim of this work is to study the phytochemical composition and antioxidant activity of different solvents fractions from the roots of Ranunculus macrophyllus Desf. Spectrophotometric and chromatographic methods were used to study the phytochemical composition; while antiradical, iron chelating ability, reducing power and lipid peroxidation were studied in-vitro. The ethyl acetate fraction showed the highest values of total phenolic compounds (271.0 ± 0.2 µg GAE/mg dry extract (d.e), flavonols (24 ± 5 µg RE/ mg d.e) and condensed tannins (129 ± 10 µg CE/mg d.e), while the hexane fraction contained the highest amount of triterpenoids (91 ± 7 µg UAE/mg d.e). The highest radical scavenging ability was recorded for the ethyl acetate fraction against DPPH (IC50 = 3.7 ± 0.1 µg/mL) and ABTS (IC50 = 81 ± 3 µg/mL) whereas the hexane fraction had the best hydrogen peroxide radical scavenging (IC50 = 380 ± 4 µg/mL). The ethyl acetate fraction had the best total antioxidant capacity (TAC = 361 ± 1 µAAE/ mg extract) and reducing power (310 ± 2 µAAE/mg extract). The β-carotene bleaching was inhibited at high rate even after 24 h by the ethyl acetate fraction (81.0 ± 0.5 %). All activities were correlated with the polyphenolic content of the fractions. Capillary LC-DAD and LC-MS/MS analysis of ethyl acetate fraction revealed high amounts of gallic acid (9.3 ± 0.6 mg/g d.e), dihydroxybenzoic acid (8.1 ± 0.2 mg/g d.e) and hesperidin (5.9 ± 0.6 mg/g d.e). With such high amounts of polyphenols and strong antioxidant activity Ranunculus macrophyllus Desf. roots could have a potential use in pharmaceutical and nutraceutical industries.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 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.