Immune Analysis Using Vitreous Optical Coherence Tomography Imaging in Rats with Steroid-Induced Glaucoma.

Glaucoma is a multifactorial pathology involving the immune system. The subclinical immune response plays a homeostatic role in healthy situations, but in pathological situations, it produces imbalances. Optical coherence tomography detects immune cells in the vitreous as hyperreflective opacities and these are subsequently characterised by computational analysis. This study monitors the changes in immunity in the vitreous in two steroid-induced glaucoma (SIG) animal models created with drug delivery systems (microspheres loaded with dexamethasone and dexamethasone/fibronectin), comparing both sexes and healthy controls over six months. SIG eyes tended to present greater intensity and a higher number of vitreous opacities (p < 0.05), with dynamic fluctuations in the percentage of isolated cells (10 µm2), non-activated cells (10-50 µm2), activated cells (50-250 µm2) and cell complexes (>250 µm2). Both SIG models presented an anti-inflammatory profile, with non-activated cells being the largest population in this study. However, smaller opacities (isolated cells) seemed to be the first responder to noxa since they were the most rounded (recruitment), coinciding with peak intraocular pressure increase, and showed the highest mean Intensity (intracellular machinery), even in the contralateral eye, and a major change in orientation (motility). Studying the features of hyperreflective opacities in the vitreous using OCT could be a useful biomarker of glaucoma.

Corrigendum to "Laponite for biomedical applications: An ophthalmological perspective" [Mater. Today Bio 24 (2024) 100935].

[This corrects the article DOI: 10.1016/j.mtbio.2023.100935.].

Antioxidant Interactions between Citrus Fruit Carotenoids and Ascorbic Acid in New Models of Animal Cell Membranes.

The regular consumption of citrus fruits by humans has been associated with lower incidence of chronic-degenerative diseases, especially those mediated by free radicals. Most of the health-promoting properties of citrus fruits derive from their antioxidant content of carotenoids and ascorbic acid (ASC). In the current work we have investigated the scavenging (against hydroxyl radical) and quenching capacities (against singlet oxygen) of four different carotenoid extracts of citrus fruits in the presence or absence of ASC (µM range) in organic solvent, aqueous solution, micelles and in an innovative biomimicking liposomal system of animal cell membrane (AML). The fruits of four varieties of citrus were selected for their distinctive carotenoid composition (liquid chromatography characterization): 'Nadorcott' mandarin and the sweet oranges 'Valencia late', 'Ruby Valencia' and 'Pinalate' mutant. The quenching activity of citrus carotenoids strongly depended on the biological assemblage: freely diffusible in organic solvent, 'Ruby Valencia' carotenoids (containing lycopene) showed the highest quenching activity, whereas 'Nadorcott' mandarin extracts, rich in ß-cryptoxanthin, prevailed in micellar systems. Interestingly, the addition of 10 µM ASC significantly increased the quenching activity of all citrus extracts in micelles: 'Valencia' orange (+53%), 'Pinalate' (+87%), 'Ruby' (4-fold higher) and 'Nadorcott' mandarins (+20%). Accurate C11-BODIPY581/591 fluorescence assays showed solid scavenging activities of all citrus extracts against AML oxidation: 'Valencia' (-61%), 'Pinalate' (-58%) and 'Ruby' oranges (-29%), and 'Nadorcott' mandarins (-70%). Indeed, all four citrus extracts tested here have balanced antioxidant properties; extracts from the 'Nadorcott' mandarin slightly prevailed overall, due, at least in part, to its high content of ß-cryptoxanthin. This study depicts some of the antioxidant interactions between citrus fruit carotenoids and ascorbic acid in models of animal cell membranes and reinforces the contribution of them in promoting health benefits for humans.

Evaluation of Programmes under the Positive Parenting Initiative in Spain:Introduction to the Special Issue / La evaluación de programas bajo la iniciativa de la parentalidad positiva en España: introducción al número especial

The prevention science has endorsed standards for evidence related to research on programme evaluation. However, some controversies persist regarding its application in the provision of family support under the European Positive Parenting initiative. This Special Issue aims to map the expansion of preventive family support programmes in Spain and to contrast the quality of the evidence against the prevention standards according with the European Family Support Network. Members of the Spanish Family Support Network made up of entities in several sectors identified 57 programmes implemented in Spain and filled in a formative evaluation sheet for each programme. The articles in this issue analysed the results of four main aspects in all programmes: description, implementation, evaluation, and impact/sustainability. The findings will inform the scope and variety of support provided and the quality of programmes in Spain, providing guidelines for improvement and addressing challenges to reinforce quality assurance in child and family services.(AU)

La ciencia de la prevención avala los estándares de evidencia relativos a la investigación en evaluación de programas. Sin embargo, hay aún controversia en cuanto a su aplicación a la prestación de apoyo familiar bajo la iniciativa europea de la parentalidad positiva. El número especial tiene por objeto mapear la extensión de los programas preventivos de apoyo familiar en España y comparar la calidad de las pruebas con los estándares de prevención de la Red Europea de Apoyo Familiar. Los miembros de la Red Española de Apoyo Familiar, formada por entidades de varios sectores, han identificado 57 programas que se utilizan en España y cumplimentado una ficha de evaluación formativa para cada programa. Los artículos de este número analizan los resultados de cuatro aspectos principales de todos los programas: descripción, implementación, evaluación e impacto/sostenibilidad. Los resultados describen el panorama y variedad del apoyo brindado y la calidad de los programas en España, proporcionando orientación sobre mejora y abordando los desafíos para reforzar la garantía de calidad en los servicios para la infancia, adolescencia y familias.(AU)

Context, Process, and Participant Response in the Implementation of Family Support Programmes in Spain / El contexto, el proceso y la respuesta de los participantes en la implementación de programas de apoyo familiar en España

Implementation research addresses how well a programme is conducted when applied in real-world conditions. However, research based on quality standards is still scarce as it requires monitoring context, process, and participant response. This study applies implementation quality standards to 57 Spanish parenting and family support programmes identified in the COST European Family Support Network project, using an ten-component evaluation sheet sheet. Descriptive analyses showed a good implementation level. The latent profile analysis identified four patterns defined by programme setting: profile 1, Social Services/NGO setting (21.1%), profile 2, Health setting (31.6%), profile 3, Multi-setting (14%), and profile 4, Educational setting (33.3%), differing in professional discipline, training, participant response, and professional perception of implementation. Profile memberships were related to programme outcomes, scaling up, and sustainability. Findings illustrate conceptual and practical challenges that researchers and professionals usually encounter during implementation, and the efforts required to deliver programmes effectively in real-world settings in Spain.(AU)

La investigación sobre implementación se ocupa de la calidad con la que se aplica un programa en condiciones del mundo real. Sin embargo, la investigación basada en patrones de calidad es aún escasa, ya que requiere supervisar el contexto, el proceso y la respuesta de los participantes. El presente estudio aplica los patrones de calidad a 57 programas españoles de apoyo parental y familiar identificados en el proyecto COST-European Family Support Network, enlos que se utilizó una hoja de evaluación de diez componentes. Los análisis descriptivos mostraron un buen nivel de implementación. El análisis de clases latentes detectó cuatro perfiles definidos por el entorno donde se aplica el programa: el perfil 1, contexto de los servicios sociales/ONG (21.1%), el perfil 2, contexto sanitario (31.6%), el perfil 3, diversos contextos (14%), y el perfil 4, entorno educativo (33.3%), que difieren en la disciplina del profesional, la formación, las respuestas de los participantes y la percepción que tiene el profesional sobre la implementación. La pertenencia a los diversos perfiles se relacionaba con los resultados del programa, su ampliación a gran escala y la sostenibilidad. Los resultados ponen de manifiesto los desafíos conceptuales y prácticos que tanto investigadores como profesionales suelen encontrar durante la implementación, así como los esfuerzos necesarios para aplicar los programas de forma efectiva en contextos reales en España.(AU)

Chronic Glaucoma Induced in Rats by a Single Injection of Fibronectin-Loaded PLGA Microspheres: IOP-Dependent and IOP-Independent Neurodegeneration.

To evaluate a new animal model of chronic glaucoma induced using a single injection of fibronectin-loaded biodegradable PLGA microspheres (Ms) to test prolonged therapies. 30 rats received a single injection of fibronectin-PLGA-Ms suspension (MsF) in the right eye, 10 received non-loaded PLGA-Ms suspension (Control), and 17 were non-injected (Healthy). Follow-up was performed (24 weeks), evaluating intraocular pressure (IOP), optical coherence tomography (OCT), histology and electroretinography. The right eyes underwent a progressive increase in IOP, but only induced cohorts reached hypertensive values. The three cohorts presented a progressive decrease in ganglion cell layer (GCL) thickness, corroborating physiological age-related loss of ganglion cells. Injected cohorts (MsF > Control) presented greater final GCL thickness. Histological exams explain this paradox: the MsF cohort showed lower ganglion cell counts but higher astrogliosis and immune response. A sequential trend of functional damage was recorded using scotopic electroretinography (MsF > Control > Healthy). It seems to be a function-structure correlation: in significant astrogliosis, early functional damage can be detected by electroretinography, and structural damage can be detected by histological exams but not by OCT. Males presented higher IOP and retinal and GCL thicknesses and lower electroretinography. A minimally invasive chronic glaucoma model was induced by a single injection of biodegradable Ms.

Mimicking chronic glaucoma over 6 months with a single intracameral injection of dexamethasone/fibronectin-loaded PLGA microspheres.

To create a chronic glaucoma animal model by a single intracameral injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (Ms) co-loaded with dexamethasone and fibronectin (MsDexaFibro). MsDexaFibro were prepared by a water-in-oil-in-water emulsion method including dexamethasone in the organic phase and fibronectin in the inner aqueous phase. To create the chronic glaucoma model, an interventionist and longitudinal animal study was performed using forty-five Long Evans rats (4-week-old). Rats received a single intracameral injection of MsDexafibro suspension (10%w/v) in the right eye. Ophthalmological parameters such as clinical signs, intraocular pressure (IOP), neuro-retinal functionality by electroretinography (ERG), retinal structural analysis by optical coherence tomography (OCT), and histology were evaluated up to six months. According to the results obtained, the model proposed was able to induce IOP increasing in both eyes over the study, higher in the injected eyes up to 6 weeks (p < 0.05), while preserving the ocular surface. OCT quantified progressive neuro-retinal degeneration (mainly in the retinal nerve fiber layer) in both eyes but higher in the injected eye. Ganglion cell functionality decreased in injected eyes, thus smaller amplitudes in PhNR were detected by ERG. In conclusion, a new chronic glaucoma animal model was created by a single injection of MsDexaFibro very similar to open-angle glaucoma occurring in humans. This model would impact in different fields such as ophthalmology, allowing long period of study of this pathology; pharmacology, evaluating the neuroprotective activity of active compounds; and pharmaceutical technology, allowing the correct evaluation of the efficacy of long-term sustained ocular drug delivery systems.

Progressive Functional and Neuroretinal Affectation in Patients With Multiple Sclerosis Treated With Fingolimod.

BACKGROUND: To evaluate the effect of fingolimod in visual function and neuroretinal structures in patients with multiple sclerosis (MS) for a period of 1 year. METHODS: This longitudinal and observational cohort study included 78 eyes of 78 patients with MS treated with fingolimod. All subjects were evaluated every 3 months during 12 months and compared with 32 patients treated with interferon beta. All patients were examined for high-contrast and low-contrast (2.5% and 1.25%) visual acuity (VA), contrast sensitivity vision (CSV) (using Pelli-Robson and CSV-1000E tests), color vision (Farnsworth D-15 and L'Anthony D-15 desaturated tests), and retinal structural measurements (retinal nerve fiber layer [RNFL] and ganglion cell layer [GCL] thickness) using optical coherence tomography (OCT) technology. RESULTS: Patients with MS treated with fingolimod for a period of 1 year showed significant reduction in 100% and 1.25% contrast VA (P = 0.009 and 0.008, respectively), an alteration of contrast sensitivity and color perception (Pelli-Robson test, CSV-1000E test, Farnsworth D-15 desaturated test, and L'Anthony D-15 desaturated test; P < 0.001), GCL thickness reduction (P = 0.007), and an average macular central thickness increase of 2.6 µm (P = 0.006). Patients with MS treated with interferon beta did not show significant changes in visual function tests neither in macular thickness measurements, but they showed a significant reduction in GCL and RNFL thicknesses. The reduction in neuroretinal structures observed by OCT was significantly higher in the interferon-beta group, but patients treated with fingolimod showed a significant increase in macular central thickness and a reduction in low contrast vision (P < 0.001). CONCLUSIONS: Patients with MS treated with fingolimod and with no clinically observable macular edema show a significant change in visual function parameters and average macular central thickness increase compared with those treated with interferon beta. These findings are probably due to subclinical macular edema produced by fingolimod, which might be considered as an indicator for pharmacovigilance of sphingosine-1-phosphate inhibitors to be improved.

Influence of Sex on Neuroretinal Degeneration: Six-Month Follow-Up in Rats With Chronic Glaucoma.

Purpose: To evaluate differences by sex in the neuroretina of rats with chronic glaucoma over 24 weeks of follow-up, and to assess by sex the influence on neurodegeneration of different methods of inducing ocular hypertension. Methods: Forty-six Long-Evans rats-18 males and 28 females-with induced chronic glaucoma were analyzed. Glaucoma was achieved via 2 models: repeatedly sclerosing the episcleral veins (9 male/14 female) or by injecting poly(lactic-co-glycolic acid) microspheres measuring 20 to 10 µm (Ms20/10) into the anterior chamber (9 male/14 female). The IOP was measured weekly by tonometer; neuroretinal function was recorded by dark/light-adapted electroretinography at baseline and weeks 12 and 24; and structure was analyzed by optical coherence tomography using the retina posterior pole, retinal nerve fiber layer and ganglion cell layer protocols at baseline and weeks 8, 12, 18, and 24. Results: Males showed statistically significant (P < 0.05) higher IOP in both chronic glaucoma models, and greater differences were found in the episcleral model at earlier stages. Males with episclerally induced glaucoma showed a statistically higher increase in retinal thickness in optical coherence tomography recordings than females and also when comparing Ms20/10 at 12 weeks. Males showed a higher percentage of retinal nerve fiber layer thickness loss in both models. Ganglion cell layer thickness loss was only detected in the Ms20/10 model. Males exhibited worse dark/light-adapted functionality in chronic glaucoma models, which worsened in the episcleral sclerosis model at 12 weeks, than females. Conclusions: Female rats with chronic glaucoma experienced lower IOP and structural loss and better neuroretinal functionality than males. Sex and the ocular hypertension-inducing method influenced neuroretinal degeneration.

Influence of Chronic Ocular Hypertension on Emmetropia: Refractive, Structural and Functional Study in Two Rat Models.

Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (<20 mmHg) and an OHT cohort (>20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long-Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time.

Transcriptional Analysis of C-Repeat Binding Factors in Fruit of Citrus Species with Differential Sensitivity to Chilling Injury during Postharvest Storage.

Citrus fruit are sensitive to chilling injury (CI) during cold storage, a peel disorder that causes economic losses. C-repeat binding factors (CBFs) are related to cold acclimation and tolerance in different plants. To explore the role of Citrus CBFs in fruit response to cold, an in silico study was performed, revealing three genes (CBF1, CBF2, and CBF3) whose expression in CI sensitive and tolerant cultivars was followed. Major changes occurred at the early stages of cold exposure (1-5 d). Interestingly, CBF1 was the most stimulated gene in the peel of CI-tolerant cultivars (Lisbon lemon, Star Ruby grapefruit, and Navelina orange), remaining unaltered in sensitive cultivars (Meyer lemon, Marsh grapefruit, and Salustiana orange). Results suggest a positive association of CBF1 expression with cold tolerance in Citrus cultivars (except for mandarins), whereas the expression of CBF2 or CBF3 genes did not reveal a clear relationship with the susceptibility to CI. Light avoidance during fruit growth reduced postharvest CI in most sensitive cultivars, associated with a rapid and transient enhance in the expression of the three CBFs. Results suggest that CBFs-dependent pathways mediate at least part of the cold tolerance responses in sensitive Citrus, indicating that CBF1 participates in the natural tolerance to CI.

Feasibility and effectiveness of 'gaining Health & wellbeing from birth to three' positive parenting programme / La viabilidad y la eficacia del programa de parentalidad positiva Ganar salud y bienestar de 0 a 3 años

Parental promotion of an adequate environment during early childhood results in healthy child development. This study evaluated the feasibility and effectiveness of the positive parenting programme, 'Gaining health and wellbeing from birth to three' (GH&W), as a universal prevention strategy. Participants were 87 parents with children < 36 months old attending 20 primary care centres. Centres were randomly assigned to three GH&W intervention levels: online course (level 1), online course plus group workshops (level 2), and online course plus group workshops plus individual support at medical check-ups (level 3), delivered by healthcare professionals. As for feasibility, participants in levels 2 and 3 reported higher utility and satisfaction with the online course than participants in level 1. Pretest-posttest comparisons and cluster analysis showed that participants in level 3 achieved the best results and were associated with a consolidated cluster characterised by improvements in health promotion activities, parental self-regulation, and satisfaction with the service, whereas participants in levels 1 and 2 showed fewer improvements and were associated with initial and transitional clusters. The GH&W programme improves the universal reach of web-based courses and efficiently activates the contribution of the primary care system to the support network for healthy child development and wellbeing

La promoción de entornos saludables en el contexto familiar durante la primera infancia es clave para el desarrollo infantil. Este estudio evaluó la viabilidad y la eficacia del programa de parentalidad positiva "Ganar salud y bienestar de 0 a 3 años" (GSB) como estrategia de prevención universal. Participaron 87 figuras parentales con hijos o hijas de menos de 36 meses usuarios de 20 centros de salud. Los centros fueron asignados aleatoriamente a tres niveles de intervención del GSB: curso online (nivel 1), curso online más talleres grupales (nivel 2) y curso online, más talleres grupales, más apoyo individual en revisiones médicas (nivel 3) implementado por los equipos de pediatría. Respecto a la viabilidad, los participantes de los niveles 2 y 3 consideraron más útil y satisfactorio el curso online que los participantes del nivel 1. En las comparaciones pretest-postest y el análisis de clúster el nivel 3 logró los mejores resultados y se asoció al clúster consolidado caracterizado por mejoras en rutinas saludables, autorregulación parental y satisfacción con el servicio, mientras que los niveles 1 y 2 mostraron menos mejoras y se asociaron al clúster inicial y de transición. El programa GSB amplía el alcance universal del curso online e implica eficazmente al sistema sanitario en la red de apoyo al desarrollo saludable y del bienestar infantil

Early Diagnosis of Multiple Sclerosis Using Swept-Source Optical Coherence Tomography and Convolutional Neural Networks Trained with Data Augmentation.

BACKGROUND: The aim of this paper is to implement a system to facilitate the diagnosis of multiple sclerosis (MS) in its initial stages. It does so using a convolutional neural network (CNN) to classify images captured with swept-source optical coherence tomography (SS-OCT). METHODS: SS-OCT images from 48 control subjects and 48 recently diagnosed MS patients have been used. These images show the thicknesses (45 × 60 points) of the following structures: complete retina, retinal nerve fiber layer, two ganglion cell layers (GCL+, GCL++) and choroid. The Cohen distance is used to identify the structures and the regions within them with greatest discriminant capacity. The original database of OCT images is augmented by a deep convolutional generative adversarial network to expand the CNN's training set. RESULTS: The retinal structures with greatest discriminant capacity are the GCL++ (44.99% of image points), complete retina (26.71%) and GCL+ (22.93%). Thresholding these images and using them as inputs to a CNN comprising two convolution modules and one classification module obtains sensitivity = specificity = 1.0. CONCLUSIONS: Feature pre-selection and the use of a convolutional neural network may be a promising, nonharmful, low-cost, easy-to-perform and effective means of assisting the early diagnosis of MS based on SS-OCT thickness data.

Characterization of the Pale Yellow Petal/Xanthophyll Esterase gene family in citrus as candidates for carotenoid esterification in fruits.

In orange-pigmented citrus fruits, the xanthophyll esters are the predominant carotenoids, but their biosynthetic origin is currently unknown. In this work, seven PYP/XES (Pale Yellow Petal/ Xanthophyll esterase) genes were identified in Citrus genomes, but only PYP1-4 and 6 contained the structural domains essential for activity. The PYP/XES expression profiles in sweet orange and in other Citrus species such as lemon, mandarin and pummelo with marked differences in fruit pigmentation and content of xanthophylls esters, showed the upregulation of PYP1,2 and 6 genes during ripening only in orange-pigmented fruits. Moreover, transcript levels of PYP1, 2 and 6 genes in peel and pulp of sweet orange were accompanied by the accumulation of xanthophyll esters during ripening. This work reports for the first time the PYP/XES gene family in Citrus and strongly suggests its involvement in xanthophyll esterification in citrus fruit tissues and its influence in carotenoid accumulation and fruit pigmentation.

Antioxidant capacity in fruit of Citrus cultivars with marked differences in pulp coloration: Contribution of carotenoids and vitamin C.

The purpose of this study was to evaluate the specific contribution of carotenoids and vitamin C to the lipophilic and hydrophilic antioxidant capacity, respectively, of the pulp of citrus fruits using the genetic diversity in pigmentation and in the carotenoid complement. To this end, six citrus varieties were selected: two mandarins, Clemenules (Citrus clementina) and Nadorcott (C. reticulata); two grapefruits (C. paradisi), Marsh and Star Ruby; and two sweet oranges (C. sinensis), Valencia late and Valencia Ruby. Total carotenoid content and composition in the pulp of fruits were very different, in relation to their color singularities. Valencia Ruby and Nadorcott had the highest carotenoid content, accumulating the former large amounts of linear carotenes (phytoene, phytofluene, and lycopene) and Nadorcott of ß-cryptoxanthin. Orange fruits contained the highest amount of vitamin C while in Nadorcott mandarin it was substantially lower. Analysis of antioxidant capacity, evaluated by 2,2'-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, in the pulp of the different fruit varieties indicated a high and positive correlation between vitamin C content and hydrophilic antioxidant capacity. Nevertheless, a weak correlation was observed between carotenoids content and lipophilic antioxidant capacity in the pulp extracts assayed by ABTS. Overall, vitamin C in the pulp of citrus fruit had an important contribution to the hydrophilic antioxidant capacity, whereas that of carotenoids to lipophilic antioxidant capacity was very variable, being the highest that of Valencia Ruby orange, with large concentrations of lycopene and phytoene, followed by Nadorcott mandarin, with high ß-cryptoxanthin content.

Carotenoids, Vitamin C, and Antioxidant Capacity in the Peel of Mandarin Fruit in Relation to the Susceptibility to Chilling Injury during Postharvest Cold Storage.

Chilling injury (CI) is a postharvest disorder occurring in the fruit of cold-sensitive Citrus species during storage at low temperatures. This study investigated the involvement of carotenoids and vitamin C, two major antioxidants of citrus peel, and the antioxidant capacity in the CI susceptibility of mandarin fruit. To that end, the fruit of three commercial varieties, Fortune, Nova, and Nadorcott, with significant differences in CI susceptibility, were selected. By on-tree fruit bagging, carotenoids and vitamin C contents were modified, and a differential effect of each cultivar on CI was observed. Carotenoid analysis in the peel revealed a strong negative correlation between total carotenoid concentration (TCC) at harvest, and specifically of ß-cryptoxanthin and violaxanthin, and CI index at the end of storage. In contrast, vitamin C content was significantly and positively correlated with CI susceptibility. The antioxidant activity assessed by the DPPH• and FRAP reflected the contribution of vitamin C to the antioxidant system, while the SOAC assay correlated positively with TTC, ß-cryptoxanthin, and violaxanthin. Collectively, the antioxidant capacity of carotenoids at harvest, as efficient singlet oxygen quenchers, suggests a protective role against the development of CI in mandarin fruit, while vitamin C is not likely playing a critical role.

Transcriptional Analysis of Carotenoids Accumulation and Metabolism in a Pink-Fleshed Lemon Mutant.

Pink lemon is a spontaneous bud mutation of lemon (Citrus limon, L. Burm. f) characterized by the production of pink-fleshed fruits due to an unusual accumulation of lycopene. To elucidate the genetic determinism of the altered pigmentation, comparative carotenoid profiling and transcriptional analysis of both the genes involved in carotenoid precursors and metabolism, and the proteins related to carotenoid-sequestering structures were performed in pink-fleshed lemon and its wild-type. The carotenoid profile of pink lemon pulp is characterized by an increased accumulation of linear carotenoids, such as lycopene, phytoene and phytofluene, from the early stages of development, reaching their maximum in mature green fruits. The distinctive phenotype of pink lemon is associated with an up-regulation and down-regulation of the genes upstream and downstream the lycopene cyclase, respectively. In particular, 9-cis epoxycarotenoid dioxygenase genes were overexpressed in pink lemon compared with the wild-type, suggesting an altered regulation of abscisic acid biosynthesis. Similarly, during early development of the fruits, genes of the carotenoid-associated proteins heat shock protein 21, fibrillin 1 and 2 and orange gene were overexpressed in the pulp of the pink-fleshed lemon compared to the wild-type, indicating its increased capacity for sequestration, stabilization or accumulation of carotenes. Altogether, the results highlighted significant differences at the transcriptomic level between the pink-fleshed lemon and its wild-type, in terms of carotenoid metabolism and the capacity of stabilization in storage structures between the two accessions. Such changes may be either responsible for the altered carotenoid accumulation or in contrast, a metabolic consequence.

Impact of high-pressure processing on the stability and bioaccessibility of bioactive compounds in Clementine mandarin juice and its cytoprotective effect on Caco-2 cells.

Mandarin juice is a rich source of antioxidant bioactive compounds. While the content and profile of bioactives are known, the impact of high-pressure processing (HPP) on their stability and bioaccessibility (BA) is unknown, but may allow obtaining safe, nutritious, and fresh-tasting juices with highly extractable bioactive compounds. The stability and BA of bioactive antioxidant compounds in untreated and HPP-treated (400 MPa/40 °C/1 min) Clementine mandarin juices, and the cytoprotective effect of its bioaccessible fractions (BF) obtained after simulated gastrointestinal digestion against H2O2-induced oxidative stress in differentiated Caco-2 cells were investigated. The BF of HPP-treated juices showed a better retention of carotenoids, flavonoids, ascorbic acid, total polyphenols and FRAP value, and slightly higher cytoprotection (mitochondrial membrane potential and ROS) than untreated juices. Therefore, HPP can be recommended as a suitable technology to retain or indeed increase antioxidant bioactives and their cytoprotective activity in mandarin juices after gastrointestinal digestion.

Neurosporaxanthin Overproduction by Fusarium fujikuroi and Evaluation of Its Antioxidant Properties.

Neurosporaxanthin (NX) is a carboxylic carotenoid produced by some filamentous fungi, including species of the genera Neurospora and Fusarium. NX biosynthetic genes and their regulation have been thoroughly investigated in Fusarium fujikuroi, an industrial fungus used for gibberellin production. In this species, carotenoid-overproducing mutants, affected in the regulatory gene carS, exhibit an upregulated expression of the NX pathway. Based on former data on a stimulatory effect of nitrogen starvation on carotenoid biosynthesis, we developed culture conditions with carS mutants allowing the production of deep-pigmented mycelia. With this method, we obtained samples with ca. 8 mg NX/g dry mass, in turn the highest concentration for this carotenoid described so far. NX-rich extracts obtained from these samples were used in parallel with carS-complemented NX-poor extracts obtained under the same conditions, to check the antioxidant properties of this carotenoid in in vitro assays. NX-rich extracts exhibited higher antioxidant capacity than NX-poor extracts, either when considering their quenching activity against [O2(1g)] in organic solvent (singlet oxygen absorption capacity (SOAC) assays) or their scavenging activity against different free radicals in aqueous solution and in liposomes. These results make NX a promising carotenoid as a possible feed or food additive, and encourage further studies on its chemical properties.