Evaluation of neurotrophic potentials of essential oils, stilbenes and oxysterols on cell models of neurodegeneration in vitro

Mieux connaitre le vieillissement et prévenir les maladies liées à l’âge est un challenge en santé publique. Plusieurs types de composés ont été étudiés : a) des dérivés du trans-resvératrol (RSV) produits au laboratoire, des aza-stilbènes, en évaluant leur potentiel cyto-toxique comparativement au RSV dans des perspectives anti-tumorales, b) des oxystérols oxydés en C7 (7-cétocholestérol (7KC), 7α-hydroxycholestérol (7α-OHC), 7β-hydroxycholestérol (7β-OHC)) intervenant dans des maladies liées à l’âge ; c) de l’huile de pépins de grenade et de l’α-tocophérol pour évaluer leurs activités cytoprotectrices ; d) des huiles essentielles Méditerranéennes (Thym, Jasmin) pour mieux connaitre leurs cibles cellulaires. Dans cette optique, comparativement au RSV, notre étude a d’abord consisté à évaluer les propriétés cytotoxiques et antioxydantes des AZA-STs et leur impact sur le statut mitochondrial en utilisant comme modèle cellulaire des cellules neuronales murines N2a. Les activités antioxydantes des AZA-STs, évaluées par différents techniques (DPPH, FRAP, KRL, PAOT), sont souvent plus importantes que celles du RSV. Les effets cytotoxiques des AZA-STs ont montré une diminution de l’activité estérasique associée à une diminution de l’adhérence cellulaire, à des dysfonctions mitochondriales, à une surproduction d’espèces réactives de l’oxygène et à des modifications au niveau de la répartition du cycle cellulaire. Les AZA-STs synthétisés se distingent donc du RSV et comme ce dernier auraient potentiellement des activités anti-tumorales. Par ailleurs, comme une augmentation de dérivés oxydés du choles-térol, notamment d’oxystérols oxydés en C7 (7KC, 7α-OHC, 7β-OHC), est souvent observée dans les liquides biologiques et les organes malades de patients atteints de maladies liées à l’âge, la mort cellulaire induite par ces oxystérols a été caractérisée sur cellules N2a à 72h et les activités cytoprotectrices de l’huile de pépins de grenade et d’α-tocophérol ont été éva-luées sur ce modèle. Le 7α-OHC n’est pas toxique alors que le 7KC et le 7β-OHC induisent une mort par oxyapoptophagie (incluant des critères de stress OXYdant, d’APOPTOse et d’autoPHAGIE) qui est atténuée par l’huile de pépins de grenade et l’α-tocophérol. Par ailleurs, pour préve-nir le vieillissement cutané, les huiles essentielles (HEs) sont utilisées en aromathérapie et en médecine traditionnelle. La composition chimique des HEs de jasmin et de thym a été déterminée par chromatographie en phase gazeuse associée à la spectrométrie de masse, leur activité antioxydante a été mesurée avec le test KRL et les activités biologiques de ces HEs ont été abordées sur des kératinocytes humains HaCaT en évaluant leurs effets à plusieurs niveaux : viabilité cellulaire, activité mitochondriale, stress oxydant, métabolisme du cho-lestérol et des acides gras et mesure du cycle cellulaire. Le profil chromatographique montre trois principaux constituants pour l’HE de jasmin (acétate de benzyle, benzoate de benzyle et linalol (ou linalool)) et pour l’HE de thym (thymol, p-cymène et γ-terpinène). Ces HEs peuvent être toxiques (induction de mort cellulaire, stress oxydant) sans modifier le cycle cellulaire à concentrations élevées, à partir de 200 µg/mL pour le thym et 400 µg/mL pour le jasmin. Ces huiles modifient aussi le métabolisme du cholestérol et des acides gras. L’ensemble de ces travaux apportent de nouvelles informations sur une série de molécules (RSV, AZA-STs,oxystérols) et de mélanges de molécules (huile de pépins de grenade, HEs de thym et de jasmin) impliquées dans différents processus de vieillissement ou utiles pour la prévention du vieillissement.A better understanding of ageing and the prevention of age-related diseases is a public health challenge. Several types of compounds have been studied: (a) trans-resveratrol (RSV) derivatives produced in the laboratory, aza-stilbenes, for their cytotoxicity compared to RSV in anti-tumour perspectives, (b) C7 oxysterols (7-ketocholesterol (7KC), 7α-hydroxycholesterol (7α-OHC), 7β-hydroxycholesterol (7β-OHC)) involved in age-related diseases; c) pomegranate seed oil and α-tocopherol to evaluate their cytoprotective activities; d) Mediterranean essential oils (Thyme, Jasmine) to better understand their biological activity. In this perspective, in comparison with the RSV, our study first consisted in evaluating the cytotoxic and antioxidant properties of AZA-STs and their impact on mitochondrial status using murine N2a neuronal cells. The antioxidant activities of AZA-STs, assessed by different techniques (DPPH, FRAP, KRL, PAOT), are often more important than those of RSV. The cytotoxic effects of AZA-STs have shown a decrease in esterase activity associated with a decrease in cell adhesion, mitochondrial dysfunction, overproduction of reactive oxygen species and changes in cell cycle distribution. The synthesised AZA-STs are therefore distinct from RSV and, like RSV, have potential anti-tumour activities. Furthermore, as an increase in oxidised cholesterol derivatives, especially C7-oxysterols (7KC, 7α-OHC, 7β-OHC), is often observed in biological fluids and diseased organs of patients with age-related diseases, cell death induced by these oxysterols was characterised in N2a cells at 72 h and the cytoprotective activities of pomegranate seed oil and α-tocopherol were evaluated in this model. 7α-OHC is not toxic, while 7KC and 7β-OHC induce oxyapoptophagy (including OXYdant stress, APOPTOsis and autoPHAGY criteria) which is attenuated by pomegranate seed oil and α-tocopherol. Furthermore, to prevent skin ageing, essential oils (EOs) are used in aromatherapy and traditional medicine. The chemical composition of jasmine and thyme EOs was determined by gas chromatography-mass spectrometry, their antioxidant activity was measured with the KRL assay and the biological activities of these EOs were addressed on human HaCaT keratinocytes by evaluating their effects at several levels: cell viability, mitochondrial activity, oxidative stress, cholesterol and fatty acid metabolism and cell cycle measurement. The chromatographic profile shows three main constituents for jasmine EO (benzyl acetate, benzyl benzoate and linalool) and for thyme EO (thymol, p-cymene and γ-terpinene). These EOs can be toxic (induction of cell death, oxidative stress) without modifying the cell cycle distribution at high concentrations, from 200 µg/mL for thyme and 400 µg/mL for jasmine. These oils also modify the metabolic pathway of cholesterol and fatty acids. All of this work provides new information on a series of molecules (RSV, AZA-STs, oxysterols) and mixtures of molecules (pomegranate seed oil, thyme and jasmine EOs) involved in various ageing processes or useful for the prevention of ageing

Evaluation des potentiels neurotrophiques d'huiles essentielles, de stilbènes et d'oxystérols sur des modèles cellulaires de neurodégénérescence in vitro

A better understanding of ageing and the prevention of age-related diseases is a public health challenge. Several types of compounds have been studied: (a) trans-resveratrol (RSV) derivatives produced in the laboratory, aza-stilbenes, for their cytotoxicity compared to RSV in anti-tumour perspectives, (b) C7 oxysterols (7-ketocholesterol (7KC), 7α-hydroxycholesterol (7α-OHC), 7β-hydroxycholesterol (7β-OHC)) involved in age-related diseases; c) pomegranate seed oil and α-tocopherol to evaluate their cytoprotective activities; d) Mediterranean essential oils (Thyme, Jasmine) to better understand their biological activity. In this perspective, in comparison with the RSV, our study first consisted in evaluating the cytotoxic and antioxidant properties of AZA-STs and their impact on mitochondrial status using murine N2a neuronal cells. The antioxidant activities of AZA-STs, assessed by different techniques (DPPH, FRAP, KRL, PAOT), are often more important than those of RSV. The cytotoxic effects of AZA-STs have shown a decrease in esterase activity associated with a decrease in cell adhesion, mitochondrial dysfunction, overproduction of reactive oxygen species and changes in cell cycle distribution. The synthesised AZA-STs are therefore distinct from RSV and, like RSV, have potential anti-tumour activities. Furthermore, as an increase in oxidised cholesterol derivatives, especially C7-oxysterols (7KC, 7α-OHC, 7β-OHC), is often observed in biological fluids and diseased organs of patients with age-related diseases, cell death induced by these oxysterols was characterised in N2a cells at 72 h and the cytoprotective activities of pomegranate seed oil and α-tocopherol were evaluated in this model. 7α-OHC is not toxic, while 7KC and 7β-OHC induce oxyapoptophagy (including OXYdant stress, APOPTOsis and autoPHAGY criteria) which is attenuated by pomegranate seed oil and α-tocopherol. Furthermore, to prevent skin ageing, essential oils (EOs) are used in aromatherapy and traditional medicine. The chemical composition of jasmine and thyme EOs was determined by gas chromatography-mass spectrometry, their antioxidant activity was measured with the KRL assay and the biological activities of these EOs were addressed on human HaCaT keratinocytes by evaluating their effects at several levels: cell viability, mitochondrial activity, oxidative stress, cholesterol and fatty acid metabolism and cell cycle measurement. The chromatographic profile shows three main constituents for jasmine EO (benzyl acetate, benzyl benzoate and linalool) and for thyme EO (thymol, p-cymene and γ-terpinene). These EOs can be toxic (induction of cell death, oxidative stress) without modifying the cell cycle distribution at high concentrations, from 200 µg/mL for thyme and 400 µg/mL for jasmine. These oils also modify the metabolic pathway of cholesterol and fatty acids. All of this work provides new information on a series of molecules (RSV, AZA-STs, oxysterols) and mixtures of molecules (pomegranate seed oil, thyme and jasmine EOs) involved in various ageing processes or useful for the prevention of ageing.Mieux connaitre le vieillissement et prévenir les maladies liées à l’âge est un challenge en santé publique. Plusieurs types de composés ont été étudiés : a) des dérivés du trans-resvératrol (RSV) produits au laboratoire, des aza-stilbènes, en évaluant leur potentiel cyto-toxique comparativement au RSV dans des perspectives anti-tumorales, b) des oxystérols oxydés en C7 (7-cétocholestérol (7KC), 7α-hydroxycholestérol (7α-OHC), 7β-hydroxycholestérol (7β-OHC)) intervenant dans des maladies liées à l’âge ; c) de l’huile de pépins de grenade et de l’α-tocophérol pour évaluer leurs activités cytoprotectrices ; d) des huiles essentielles Méditerranéennes (Thym, Jasmin) pour mieux connaitre leurs cibles cellulaires. Dans cette optique, comparativement au RSV, notre étude a d’abord consisté à évaluer les propriétés cytotoxiques et antioxydantes des AZA-STs et leur impact sur le statut mitochondrial en utilisant comme modèle cellulaire des cellules neuronales murines N2a. Les activités antioxydantes des AZA-STs, évaluées par différents techniques (DPPH, FRAP, KRL, PAOT), sont souvent plus importantes que celles du RSV. Les effets cytotoxiques des AZA-STs ont montré une diminution de l’activité estérasique associée à une diminution de l’adhérence cellulaire, à des dysfonctions mitochondriales, à une surproduction d’espèces réactives de l’oxygène et à des modifications au niveau de la répartition du cycle cellulaire. Les AZA-STs synthétisés se distingent donc du RSV et comme ce dernier auraient potentiellement des activités anti-tumorales. Par ailleurs, comme une augmentation de dérivés oxydés du choles-térol, notamment d’oxystérols oxydés en C7 (7KC, 7α-OHC, 7β-OHC), est souvent observée dans les liquides biologiques et les organes malades de patients atteints de maladies liées à l’âge, la mort cellulaire induite par ces oxystérols a été caractérisée sur cellules N2a à 72h et les activités cytoprotectrices de l’huile de pépins de grenade et d’α-tocophérol ont été éva-luées sur ce modèle. Le 7α-OHC n’est pas toxique alors que le 7KC et le 7β-OHC induisent une mort par oxyapoptophagie (incluant des critères de stress OXYdant, d’APOPTOse et d’autoPHAGIE) qui est atténuée par l’huile de pépins de grenade et l’α-tocophérol. Par ailleurs, pour préve-nir le vieillissement cutané, les huiles essentielles (HEs) sont utilisées en aromathérapie et en médecine traditionnelle. La composition chimique des HEs de jasmin et de thym a été déterminée par chromatographie en phase gazeuse associée à la spectrométrie de masse, leur activité antioxydante a été mesurée avec le test KRL et les activités biologiques de ces HEs ont été abordées sur des kératinocytes humains HaCaT en évaluant leurs effets à plusieurs niveaux : viabilité cellulaire, activité mitochondriale, stress oxydant, métabolisme du cho-lestérol et des acides gras et mesure du cycle cellulaire. Le profil chromatographique montre trois principaux constituants pour l’HE de jasmin (acétate de benzyle, benzoate de benzyle et linalol (ou linalool)) et pour l’HE de thym (thymol, p-cymène et γ-terpinène). Ces HEs peuvent être toxiques (induction de mort cellulaire, stress oxydant) sans modifier le cycle cellulaire à concentrations élevées, à partir de 200 µg/mL pour le thym et 400 µg/mL pour le jasmin. Ces huiles modifient aussi le métabolisme du cholestérol et des acides gras. L’ensemble de ces travaux apportent de nouvelles informations sur une série de molécules (RSV, AZA-STs,oxystérols) et de mélanges de molécules (huile de pépins de grenade, HEs de thym et de jasmin) impliquées dans différents processus de vieillissement ou utiles pour la prévention du vieillissement

Evaluation des potentiels neurotrophiques d'huiles essentielles, de stilbènes et d'oxystérols sur des modèles cellulaires de neurodégénérescence in vitro

A better understanding of ageing and the prevention of age-related diseases is a public health challenge. Several types of compounds have been studied: (a) trans-resveratrol (RSV) derivatives produced in the laboratory, aza-stilbenes, for their cytotoxicity compared to RSV in anti-tumour perspectives, (b) C7 oxysterols (7-ketocholesterol (7KC), 7α-hydroxycholesterol (7α-OHC), 7β-hydroxycholesterol (7β-OHC)) involved in age-related diseases; c) pomegranate seed oil and α-tocopherol to evaluate their cytoprotective activities; d) Mediterranean essential oils (Thyme, Jasmine) to better understand their biological activity. In this perspective, in comparison with the RSV, our study first consisted in evaluating the cytotoxic and antioxidant properties of AZA-STs and their impact on mitochondrial status using murine N2a neuronal cells. The antioxidant activities of AZA-STs, assessed by different techniques (DPPH, FRAP, KRL, PAOT), are often more important than those of RSV. The cytotoxic effects of AZA-STs have shown a decrease in esterase activity associated with a decrease in cell adhesion, mitochondrial dysfunction, overproduction of reactive oxygen species and changes in cell cycle distribution. The synthesised AZA-STs are therefore distinct from RSV and, like RSV, have potential anti-tumour activities. Furthermore, as an increase in oxidised cholesterol derivatives, especially C7-oxysterols (7KC, 7α-OHC, 7β-OHC), is often observed in biological fluids and diseased organs of patients with age-related diseases, cell death induced by these oxysterols was characterised in N2a cells at 72 h and the cytoprotective activities of pomegranate seed oil and α-tocopherol were evaluated in this model. 7α-OHC is not toxic, while 7KC and 7β-OHC induce oxyapoptophagy (including OXYdant stress, APOPTOsis and autoPHAGY criteria) which is attenuated by pomegranate seed oil and α-tocopherol. Furthermore, to prevent skin ageing, essential oils (EOs) are used in aromatherapy and traditional medicine. The chemical composition of jasmine and thyme EOs was determined by gas chromatography-mass spectrometry, their antioxidant activity was measured with the KRL assay and the biological activities of these EOs were addressed on human HaCaT keratinocytes by evaluating their effects at several levels: cell viability, mitochondrial activity, oxidative stress, cholesterol and fatty acid metabolism and cell cycle measurement. The chromatographic profile shows three main constituents for jasmine EO (benzyl acetate, benzyl benzoate and linalool) and for thyme EO (thymol, p-cymene and γ-terpinene). These EOs can be toxic (induction of cell death, oxidative stress) without modifying the cell cycle distribution at high concentrations, from 200 µg/mL for thyme and 400 µg/mL for jasmine. These oils also modify the metabolic pathway of cholesterol and fatty acids. All of this work provides new information on a series of molecules (RSV, AZA-STs, oxysterols) and mixtures of molecules (pomegranate seed oil, thyme and jasmine EOs) involved in various ageing processes or useful for the prevention of ageing.Mieux connaitre le vieillissement et prévenir les maladies liées à l’âge est un challenge en santé publique. Plusieurs types de composés ont été étudiés : a) des dérivés du trans-resvératrol (RSV) produits au laboratoire, des aza-stilbènes, en évaluant leur potentiel cyto-toxique comparativement au RSV dans des perspectives anti-tumorales, b) des oxystérols oxydés en C7 (7-cétocholestérol (7KC), 7α-hydroxycholestérol (7α-OHC), 7β-hydroxycholestérol (7β-OHC)) intervenant dans des maladies liées à l’âge ; c) de l’huile de pépins de grenade et de l’α-tocophérol pour évaluer leurs activités cytoprotectrices ; d) des huiles essentielles Méditerranéennes (Thym, Jasmin) pour mieux connaitre leurs cibles cellulaires. Dans cette optique, comparativement au RSV, notre étude a d’abord consisté à évaluer les propriétés cytotoxiques et antioxydantes des AZA-STs et leur impact sur le statut mitochondrial en utilisant comme modèle cellulaire des cellules neuronales murines N2a. Les activités antioxydantes des AZA-STs, évaluées par différents techniques (DPPH, FRAP, KRL, PAOT), sont souvent plus importantes que celles du RSV. Les effets cytotoxiques des AZA-STs ont montré une diminution de l’activité estérasique associée à une diminution de l’adhérence cellulaire, à des dysfonctions mitochondriales, à une surproduction d’espèces réactives de l’oxygène et à des modifications au niveau de la répartition du cycle cellulaire. Les AZA-STs synthétisés se distingent donc du RSV et comme ce dernier auraient potentiellement des activités anti-tumorales. Par ailleurs, comme une augmentation de dérivés oxydés du choles-térol, notamment d’oxystérols oxydés en C7 (7KC, 7α-OHC, 7β-OHC), est souvent observée dans les liquides biologiques et les organes malades de patients atteints de maladies liées à l’âge, la mort cellulaire induite par ces oxystérols a été caractérisée sur cellules N2a à 72h et les activités cytoprotectrices de l’huile de pépins de grenade et d’α-tocophérol ont été éva-luées sur ce modèle. Le 7α-OHC n’est pas toxique alors que le 7KC et le 7β-OHC induisent une mort par oxyapoptophagie (incluant des critères de stress OXYdant, d’APOPTOse et d’autoPHAGIE) qui est atténuée par l’huile de pépins de grenade et l’α-tocophérol. Par ailleurs, pour préve-nir le vieillissement cutané, les huiles essentielles (HEs) sont utilisées en aromathérapie et en médecine traditionnelle. La composition chimique des HEs de jasmin et de thym a été déterminée par chromatographie en phase gazeuse associée à la spectrométrie de masse, leur activité antioxydante a été mesurée avec le test KRL et les activités biologiques de ces HEs ont été abordées sur des kératinocytes humains HaCaT en évaluant leurs effets à plusieurs niveaux : viabilité cellulaire, activité mitochondriale, stress oxydant, métabolisme du cho-lestérol et des acides gras et mesure du cycle cellulaire. Le profil chromatographique montre trois principaux constituants pour l’HE de jasmin (acétate de benzyle, benzoate de benzyle et linalol (ou linalool)) et pour l’HE de thym (thymol, p-cymène et γ-terpinène). Ces HEs peuvent être toxiques (induction de mort cellulaire, stress oxydant) sans modifier le cycle cellulaire à concentrations élevées, à partir de 200 µg/mL pour le thym et 400 µg/mL pour le jasmin. Ces huiles modifient aussi le métabolisme du cholestérol et des acides gras. L’ensemble de ces travaux apportent de nouvelles informations sur une série de molécules (RSV, AZA-STs,oxystérols) et de mélanges de molécules (huile de pépins de grenade, HEs de thym et de jasmin) impliquées dans différents processus de vieillissement ou utiles pour la prévention du vieillissement

Characterization and catalytic reactivity of xerogel catalysts based on mesoporous zirconia doped with telluric acid prepared by sol–gel method: mechanistic study of acetic acid esterification with benzyl alcohol

International audienceOur work is focused on the research of new zirconia doped telluric acid catalysts prepared with sol–gel method. Optimization of different preparation parameters of the catalyst, such as the HNO3 assisted synthesis, molar ratio nTe(OH)6/nZr, and calcination temperature, was studied. Catalysts were characterized by N2-physisorption at 77 K, X-ray diffraction, UV–Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), Electron Scanning Microscopy, and surface acidity titration. The catalytic activity was tested in the esterification reaction of benzyl alcohol with acetic acid. The addition of HNO3 in the gelling step greatly improves the acidity of the catalyst through the development of the texture. Doping of zirconia by telluric acid improves the acidity of the catalyst and the catalytic performance, but this improvement does not follow the increase in the quantity of the doping agent in the catalyst. However, calcination of the catalyst allows the development of tetragonal ZrO2 phase and causes a loss in acidity and consequently a decrease in catalytic activity. Kinetics and mechanism study indicates that the catalytic reaction is of first order and is by the Eley–Rideal mechanism in which the adsorbed acetic acid species react with benzyl alcohol in the fluid phase to form the corresponding ester. By the application of Eyring’s theory shows that the adsorption step is endothermic and that a fast associative mechanism occurs between the adsorbed species and the second reagent

Role of Bioactive Compounds in the Regulation of Mitochondrial Dysfunctions in Brain and Age-Related Neurodegenerative Diseases

Mitochondria are multifunctional organelles that participate in a wide range of metabolic processes, including energy production and biomolecule synthesis. The morphology and distribution of intracellular mitochondria change dynamically, reflecting a cell’s metabolic activity. Oxidative stress is defined as a mismatch between the body’s ability to neutralise and eliminate reactive oxygen and nitrogen species (ROS and RNS). A determination of mitochondria failure in increasing oxidative stress, as well as its implications in neurodegenerative illnesses and apoptosis, is a significant developmental process of focus in this review. The neuroprotective effects of bioactive compounds linked to neuronal regulation, as well as related neuronal development abnormalities, will be investigated. In conclusion, the study of secondary components and the use of mitochondrial features in the analysis of various neurodevelopmental diseases has enabled the development of a new class of mitochondrial-targeted pharmaceuticals capable of alleviating neurodegenerative disease states and enabling longevity and healthy ageing for the vast majority of people

Characterization of Cell Death Induced by Imine Analogs of Trans-Resveratrol: Induction of Mitochondrial Dysfunction and Overproduction of Reactive Oxygen Species Leading to, or Not, Apoptosis without the Increase in the S-Phase of the Cell Cycle

Trans-resveratrol (RSV) is a non-flavonoid polyphenol (stilbene) with numerous biological activities, such as anti-tumor activities. However, RSV is rapidly metabolized, which limits its therapeutic use. The availability of RSV analogues with similar activities for use in vivo is therefore a major challenge. For this purpose, several isomeric analogues of RSV, aza-stilbenes (AZA-ST 1a–g), were synthesized, and their toxicities were characterized and compared to those of RSV on murine N2a neuronal cells using especially flow cytometric methods. All AZA-ST 1a–g have an inhibitory concentration 50 (IC50) between 11.3 and 25 µM when determined by the crystal violet assay, while that of RSV is 14.5 µM. This led to the characterization of AZA-ST 1a–g—induced cell death, compared to RSV, using three concentrations encompassing the IC50s (6.25, 12.5 and 25 µM). For AZA-ST 1a–g and RSV, an increase in plasma membrane permeability to propidium iodide was observed, and the proportion of cells with depolarized mitochondria measured with DiOC6(3) was increased. An overproduction of reactive oxygen species (ROS) was also observed on whole cells and at the mitochondrial level using dihydroethidium and MitoSox Red, respectively. However, only RSV induced a mode of cell death by apoptosis associated with a marked increase in the proportion of cells with condensed and/or fragmented nuclei (12.5 µM: 22 ± 9%; 25 µM: 80 ± 10%) identified after staining with Hoechst 33342 and which are characteristic of apoptotic cells. With AZA-ST, a slight but significant increase in the percentage of apoptotic cells was only detected with AZA-ST 1b (25 µM: 17 ± 1%) and AZA-ST 1d (25 µM: 26 ± 4%). Furthermore, only RSV induced significant cell cycle modifications associated with an increase in the percentage of cells in the S phase. Thus, AZA-ST 1a–g—induced cell death is characterized by an alteration of the plasma membrane, an induction of mitochondrial depolarization (loss of ΔΨm), and an overproduction of ROS, which may or may not result in a weak induction of apoptosis without modification of the distribution of the cells in the different phases of the cell cycle

Cytotoxic and Antioxidant Activities of Imine Analogs of Trans-Resveratrol towards Murine Neuronal N2a Cells

Trans-resveratrol is a natural polyphenol showing numerous biological properties, especially anti-tumoral and antioxidant activity. Among numerous resveratrol derivatives, aza-stilbenes, which bear an imine bound, show interesting biological activities. In the present study, we synthesized a series of imine analogs of trans-resveratrol (seven aza-stilbenes) following an easy and low-cost procedure of green chemistry. The toxicity of synthesized aza-stilbenes, which is currently unknown, was evaluated on murine neuronal N2a cells, comparatively to trans-resveratrol, by considering: cell density evaluated by staining with sulforhodamine 101; esterase activity, which is a criteria of cell viability, by staining with fluorescein diacetate; and transmembrane mitochondrial potential, which is known to decrease during cell death, by staining with DiOC6(3) using flow cytometry. In addition, the antioxidant activity was quantified with the KRL (Kit Radicaux Libres) assay, the DPPH (2,2′-diphenyl-1-picrylhydrazyl radical) assay and the FRAP (ferric reducing antioxidant power) assay. The PAOT (Pouvoir Antioxidant Total) score was also used. The aza-stilbenes provide different cytotoxic and antioxidant activities, which are either higher or lower than those of trans-resveratrol. Based on their cytotoxic and antioxidant characteristics, all synthesized aza-stilbenes are distinguished from trans-resveratrol

Protective effects of milk thistle (Sylibum marianum) seed oil and α-tocopherol against 7β-hydroxycholesterol-induced peroxisomal alterations in murine C2C12 myoblasts: Nutritional insights associated with the concept of pexotherapy

International audiencePeroxisomes play an important role in regulating cell metabolism and RedOx homeostasis. Peroxisomal dysfunctions favor oxidative stress and cell death. The ability of 7β-hydroxycholesterol (7β-OHC; 50 μM, 24 h), known to be increased in patients with age-related diseases such as sarcopenia, to trigger oxidative stress, mitochondrial and peroxisomal dysfunction was studied in murine C2C12 myoblasts. The capacity of milk thistle seed oil (MTSO, 100 μg/mL) as well as α-tocopherol (400 µM; reference cytoprotective agent) to counteract the toxic effects of 7β-OHC, mainly at the peroxisomal level were evaluated. The impacts of 7β-OHC, in the presence or absence of MTSO or α-tocopherol, were studied with complementary methods: measurement of cell density and viability, quantification of reactive oxygen species (ROS) production and transmembrane mitochondrial potential (ΔΨm), evaluation of peroxisomal mass as well as topographic, morphologic and functional peroxisomal changes. Our results indicate that 7β-OHC induces a loss of cell viability and a decrease of cell adhesion associated with ROS overproduction, alterations of mitochondrial ultrastructure, a drop of ΔΨm, and several peroxisomal modifications. In the presence of 7β-OHC, comparatively to untreated cells, important quantitative and qualitative peroxisomal modifications were also identified: a) a reduced number of peroxisomes with abnormal sizes and shapes, mainly localized in cytoplasmic vacuoles, were observed; b) the peroxisomal mass was decreased as indicated by lower protein and mRNA levels of the peroxisomal ABCD3 transporter; c) lower mRNA level of Pex5 involved in peroxisomal biogenesis as well as higher mRNA levels of Pex13 and Pex14, involved in peroxisomal biogenesis and/or pexophagy, was found; d) lower levels of ACOX1 and MFP2 enzymes, implicated in peroxisomal β-oxidation, were detected; e) higher levels of very-long-chain fatty acids, which are substrates of peroxisomal β-oxidation, were found. These different cytotoxic effects were strongly attenuated by MTSO, in the same range of order as with α-tocopherol. These findings underline the interest of MTSO and α-tocopherol in the prevention of peroxisomal damages (pexotherapy)

Saffron (<i>Crocus sativus</i> L.): A Source of Nutrients for Health and for the Treatment of Neuropsychiatric and Age-Related Diseases

Saffron (Crocus sativus L.) is a medicinal plant, originally cultivated in the East and Middle East, and later in some Mediterranean countries. Saffron is obtained from the stigmas of the plant. Currently, the use of saffron is undergoing a revival. The medicinal virtues of saffron, its culinary use and its high added value have led to the clarification of its phytochemical profile and its biological and therapeutic characteristics. Saffron is rich in carotenoids and terpenes. The major products of saffron are crocins and crocetin (carotenoids) deriving from zeaxanthin, pirocrocin and safranal, which give it its taste and aroma, respectively. Saffron and its major compounds have powerful antioxidant and anti-inflammatory properties in vitro and in vivo. Anti-tumor properties have also been described. The goal of this review is to present the beneficial effects of saffron and its main constituent molecules on neuropsychiatric diseases (depression, anxiety and schizophrenia) as well as on the most frequent age-related diseases (cardiovascular, ocular and neurodegenerative diseases, as well as sarcopenia). Overall, the phytochemical profile of saffron confers many beneficial virtues on human health and, in particular, on the prevention of age-related diseases, which is a major asset reinforcing the interest for this medicinal plant

In Vitro Evaluation of the Effects of 7-Ketocholesterol and 7β-Hydroxycholesterol on the Peroxisomal Status: Prevention of Peroxisomal Damages and Concept of Pexotherapy

Correspondence to [email protected]. First Online: 01 December 2023International audience7-Ketocholesterol and 7β-hydroxycholesterol are most often derived from the autoxidation of cholesterol. Their quantities are often increased in the body fluids and/or diseased organs of patients with age-related diseases such as cardiovascular diseases, Alzheimer’s disease, age-related macular degeneration, and sarcopenia which are frequently associated with a rupture of RedOx homeostasis leading to a high oxidative stress contributing to cell and tissue damages. On murine cells from the central nervous system (158N oligodendrocytes, microglial BV-2 cells, and neuronal N2a cells) as well as on C2C12 murine myoblasts, these two oxysterols can induce a mode of cell death which is associated with qualitative, quantitative, and functional modifications of the peroxisome. These changes can be revealed by fluorescence microscopy (apotome, confocal microscopy), transmission electron microscopy, flow cytometry, quantitative reverse transcription polymerase chain reaction (RT-qPCR), and gas chromatography-coupled with mass spectrometry (GC-MS). Noteworthy, several natural molecules, including ω3 fatty acids, polyphenols, and α-tocopherol, as well as several Mediterranean oils [argan and olive oils, Milk-thistle (Sylibum marianum) and Pistacia lenticus seed oils], have cytoprotective properties and attenuate 7-ketocholesterol- and 7β-hydroxycholesterol-induced peroxisomal modifications. These observations led to the concept of pexotherapy