Cytoprotective effects of α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol on 7-ketocholesterol - Induced oxiapoptophagy: Major roles of PI3-K / PDK-1 / Akt signaling pathway and glutathione peroxidase activity in cell rescue.

On murine N2a cells, 7-ketocholesterol induced an oxiapotophagic mode of cell death characterized by oxidative stress (reactive oxygen species overproduction on whole cells and at the mitochondrial level; lipid peroxidation), apoptosis induction (caspase-9, -3 and -7 cleavage, PARP degradation) and autophagy (increased ratio LC3-II / LC3-I). Oxidative stress was strongly attenuated by diphenyleneiodonium chloride which inhibits NAD(P)H oxidase. Mitochondrial and peroxisomal morphological and functional changes were also observed. Down regulation of PDK1 / Akt signaling pathways as well as of GSK3 / Mcl-1 and Nrf2 pathways were simultaneously observed in 7-ketocholesterol-induced oxiapoptophagy. These events were prevented by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol. The inhibition of the cytoprotection by LY-294002, a PI3-K inhibitor, demonstrated an essential role of PI3-K in cell rescue. The rupture of oxidative stress in 7-ketocholesterol-induced oxiapoptophagy was also associated with important modifications of glutathione peroxidase, superoxide dismutase and catalase activities as well as of glutathione peroxidase-1, superoxide dismutase-1 and catalase level and expression. These events were also counteracted by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol. The inhibition of the cytoprotection by mercaptosuccinic acid, a glutathione peroxidase inhibitor, showed an essential role of this enzyme in cell rescue. Altogether, our data support that the reactivation of PI3-K and glutathione peroxidase activities by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol are essential to prevent 7KC-induced oxiapoptophagy.

Effects of polyphenols and their metabolites on age-related diseases.

Aging contributes to the progressive loss of cellular biological functions and increases the risk of age-related diseases. Cardiovascular diseases, some neurological disorders and cancers are generally classified as age-related diseases that affect the lifespan of individuals. These diseases result from the accumulation of cellular damage and reduced activity of protective stress response pathways, which can lead to inflammation and oxidative stress, which play a key role in the aging process. There is now increasing interest in the therapeutic effects of edible plants for the prevention of various diseases, including those associated with aging. It has become clear that the beneficial effects of these foods are due, at least in part, to the high concentration of bioactive phenolic compounds with low side effects. Antioxidants are the most abundant, and their high consumption in the Mediterranean diet has been associated with slower ageing in humans. Extensive human dietary intervention studies strongly suggest that polyphenol supplementation protects against the development of degenerative diseases, especially in the elderly. In this review, we present data on the biological effects of plant polyphenols in the context of their relevance to human health, ageing and the prevention of age-related diseases.

7ß-Hydroxycholesterol and 7-ketocholesterol: New oxidative stress biomarkers of sarcopenia inducing cytotoxic effects on myoblasts and myotubes.

Aging is a complex biological process which can be associated with skeletal muscle degradation leading to sarcopenia. The aim of this study consisted i) to determine the oxidative and inflammatory status of sarcopenic patients and ii) to clarify the impact of oxidative stress on myoblasts and myotubes. To this end, various biomarkers of inflammation (C-reactive protein (CRP), TNF-α, IL-6, IL-8, leukotriene B4 (LTB4)) and oxidative stress (malondialdehyde, conjugated dienes, carbonylated proteins and antioxidant enzymes: catalase, superoxide dismutase, glutathione peroxidase) as well as oxidized derivatives of cholesterol formed by cholesterol autoxidation (7-ketocholesterol, 7ß-hydroxycholesterol), were analyzed. Apelin, a myokine which contributes to muscle strength, was also quantified. To this end, a case-control study was conducted to evaluate the RedOx and inflammatory status in 45 elderly subjects (23 non-sarcopenic; 22 sarcopenic) from 65 years old and higher. SARCopenia-Formular (SARC-F) and Timed Up and Go (TUG) tests were used to distinguish between sarcopenic and non-sarcopenic subjects. By using red blood cells, plasma and/or serum, we observed in sarcopenic patients an increased activity of major antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase) associated with lipid peroxidation and protein carbonylation (increased level of malondialdehyde, conjugated dienes and carbonylated proteins). Higher levels of 7-ketocholesterol and 7ß-hydroxycholesterol were also observed in the plasma of sarcopenic patients. Significant differences were only observed with 7ß-hydroxycholesterol. In sarcopenic patients comparatively to non-sarcopenic subjects, significant increase of CRP, LTB4 and apelin were observed whereas similar levels of TNF-α, IL-6 and IL-8 were found. The increased plasma level of 7-ketocholesterol and 7ß-hydroxycholesterol in sarcopenic patients led us to study the cytotoxic effect of these oxysterols on undifferentiated (myoblasts) and differentiated (myotubes) murine C2C12 cells. With the fluorescein diacetate and sulforhodamine 101 assays, an induction of cell death was observed both on undifferentiated and differentiated cells: the cytotoxic effects were less pronounced with 7-ketocholesterol. In addition, IL-6 secretion was never detected whatever the culture conditions, TNF-α secretion was significantly increased on undifferentiated and differentiated C2C12 cells treated with 7-ketocholesterol- and 7ß-hydroxycholesterol, and IL-8 secretion was increased on differentiated cells. 7-ketocholesterol- and 7ß-hydroxycholesterol-induced cell death was strongly attenuated by α-tocopherol and Pistacia lentiscus L. seed oil both on myoblasts and/or myotubes. TNF-α and/or IL-8 secretions were reduced by α-tocopherol and Pistacia lentiscus L. seed oil. Our data support the hypothesis that the enhancement of oxidative stress observed in sarcopenic patients could contribute, especially via 7ß-hydroxycholesterol, to skeletal muscle atrophy and inflammation via cytotoxic effects on myoblasts and myotubes. These data bring new elements to understand the pathophysiology of sarcopenia and open new perspectives for the treatment of this frequent age-related disease.

Anti-glycation, antiplatelet and antioxidant effects of different pomegranate parts.

BACKGROUND: Platelet aggregation and advanced glycation end products (AGEs) and oxidative stress are known as key factors for the development of cardiovascular diseases and diabetic complications. In this context, fruit and vegetable consumption, good sources of antioxidant compounds have been largely reported as an effective way of preventing human against these diseases. The current study focuses on the evaluation of antioxidant, antiplatelet and anti-glycation activities of pomegranate (Punica granatum L.) flowers (PF), leaves (PL), peel (PP) juice (PJ) and seeds oil (PSO). METHODS: Antioxidant activities was measured against ABTS radical and lipid peroxidation. Antiglycation activity was determined using the formation of AGE fluorescence intensity in the BSA/ribose system. Antiplatelet activity was measured in platelet rich plasma (PRP) against adenosine diphosphate (ADP), Collagen and arachidonic acid (AA). RESULTS: PF extract displayed the highest antioxidant activity against ABTS and lipid peroxidation with IC50 values of 0.7 mg/mL and 0.63 mg/mL respectively. For anti-glycation activity, PP, PF and PL inhibited moderately the pentosidine-like AGEs formation compared to positive controls with AGE-IC50 value of 0.4 mg/mL. PJ and PSO haven't any anti-AGE effect. All the extracts selectively inhibited platelet aggregation caused by one, two or three inducers in dose dependent manner. PF was the most potent inhibitor caused by all three inducers, with inhibitory effects ranging from 35.6 to 66.6%. PP and PJ exhibited antiplatelet effect against both ADP and collagen and PL and PSO only against AA. CONCLUSIONS: These results suggest that some pomegranate extracts exert potential in vitro anti-glycative and antiplatelet activities.

Oxiapoptophagy in Age-Related Diseases. Comment on Ouyang et al. 7-Ketocholesterol Induces Oxiapoptophagy and Inhibits Osteogenic Differentiation in MC3T3-E1 Cells. Cells 2022, 11, 2882.

Due to the increase in life span and life expectancy, which can, however, be more or less pronounced depending on the economic, social and cultural context [...].

Cytoprotective activities of representative nutrients from the Mediterranean diet and of Mediterranean oils against 7-ketocholesterol- and 7ß-hydroxycholesterol-induced cytotoxicity: Application to age-related diseases and civilization diseases.

7-ketocholesterol and 7ß-hydroxycholesterol are two oxysterols mainly formed by the autoxidation of cholesterol. These two molecules are interconvertible via specific enzymes. These two oxysterols are often observed at increased amounts in biological fluids as well as tissues and organs affected during age-related diseases and in diseases of civilization such as cardiovascular, neurodegenerative, and ocular diseases as well as type 2 diabetes and metabolic syndrome. Noteworthy, 7-ketocholesterol and 7ß-hydroxycholesterol induce oxidative stress and inflammation, which are frequently observed in patients with age-related and civilization diseases. For this reason, the involvement of these two oxysterols in the pathophysiology of these diseases is widely suspected. In addition, the toxicity of these oxysterols can lead to death by oxiapoptophagy characterized by oxidative stress, apoptosis induction and autophagy criteria. To prevent, or even treat, certain age-related or civilization diseases associated with increased levels of 7-ketocholesterol and 7ß-hydroxycholesterol, the identification of molecules or mixtures of molecules attenuating or inhibiting the toxic effects of these oxysterols allows to consider new treatments. In this context, many nutrients present in significant amounts in the Mediterranean diet, especially tocopherols, fatty acids, and polyphenols, have shown cytoprotective activities as well as several Mediterranean oils (argan and olive oils, milk thistle seed oil, and pistacia lentiscus seed oil). Consequently, a nutraceutical approach, rich in nutrients present in the Mediterranean diet, could thus make it possible to counteract certain age-related and civilization diseases associated with increased levels of 7-ketocholesterol and 7ß-hydroxycholesterol.

Role of Diet and Nutrients in SARS-CoV-2 Infection: Incidence on Oxidative Stress, Inflammatory Status and Viral Production.

Coronavirus illness (COVID-19) is an infectious pathology generated by intense severe respiratory syndrome coronavirus 2 (SARS-CoV-2). This infectious disease has emerged in 2019. The COVID-19-associated pandemic has considerably affected the way of life and the economy in the world. It is consequently crucial to find solutions allowing remedying or alleviating the effects of this infectious disease. Natural products have been in perpetual application from immemorial time given that they are attested to be efficient towards several illnesses without major side effects. Various studies have shown that plant extracts or purified molecules have a promising inhibiting impact towards coronavirus. In addition, it is substantial to understand the characteristics, susceptibility and impact of diet on patients infected with COVID-19. In this review, we recapitulate the influence of extracts or pure molecules from medicinal plants on COVID-19. We approach the possibilities of plant treatment/co-treatment and feeding applied to COVID-19. We also show coronavirus susceptibility and complications associated with nutrient deficiencies and then discuss the major food groups efficient on COVID-19 pathogenesis. Then, we covered emerging technologies using plant-based SARS-CoV-2 vaccine. We conclude by giving nutrient and plants curative therapy recommendations which are of potential interest in the COVID-19 infection and could pave the way for pharmacological treatments or co-treatments of COVID-19.

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

Peroxisomes play an important role in regulating cell metabolism and RedOx homeostasis. Peroxisomal dysfunctions favor oxidative stress and cell death. The ability of 7ß-hydroxycholesterol (7ß-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 7ß-OHC, mainly at the peroxisomal level were evaluated. The impacts of 7ß-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 7ß-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 7ß-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 ß-oxidation, were detected; e) higher levels of very-long-chain fatty acids, which are substrates of peroxisomal ß-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 (Crocus sativus 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.

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.

Antioxidant Properties and Cytoprotective Effect of Pistacia lentiscus L. Seed Oil against 7ß-Hydroxycholesterol-Induced Toxicity in C2C12 Myoblasts: Reduction in Oxidative Stress, Mitochondrial and Peroxisomal Dysfunctions and Attenuation of Cell Death.

Aging is characterized by a progressive increase in oxidative stress, which favors lipid peroxidation and the formation of cholesterol oxide derivatives, including 7ß-hydroxycholesterol (7ß-OHC). This oxysterol, which is known to trigger oxidative stress, inflammation, and cell death, could contribute to the aging process and age-related diseases, such as sarcopenia. Identifying molecules or mixtures of molecules preventing the toxicity of 7ß-OHC is therefore an important issue. This study consists of determining the chemical composition of Tunisian Pistacia lentiscus L. seed oil (PLSO) used in the Tunisian diet and evaluating its ability to counteract the cytotoxic effects induced by 7ß-OHC in murine C2C12 myoblasts. The effects of 7ß-OHC (50 µM; 24 h), associated or not with PLSO, were studied on cell viability, oxidative stress, and on mitochondrial and peroxisomal damages induction. α-Tocopherol (400 µM) was used as the positive control for cytoprotection. Our data show that PLSO is rich in bioactive compounds; it contains polyunsaturated fatty acids, and several nutrients with antioxidant properties: phytosterols, α-tocopherol, carotenoids, flavonoids, and phenolic compounds. When associated with PLSO (100 µg/mL), the 7ß-OHC-induced cytotoxic effects were strongly attenuated. The cytoprotection was in the range of those observed with α-tocopherol. This cytoprotective effect was characterized by prevention of cell death and organelle dysfunction (restoration of cell adhesion, cell viability, and plasma membrane integrity; prevention of mitochondrial and peroxisomal damage) and attenuation of oxidative stress (reduction in reactive oxygen species overproduction in whole cells and at the mitochondrial level; decrease in lipid and protein oxidation products formation; and normalization of antioxidant enzyme activities: glutathione peroxidase (GPx) and superoxide dismutase (SOD)). These results provide evidence that PLSO has similar antioxidant properties than α-tocopherol used at high concentration and contains a mixture of molecules capable to attenuate 7ß-OHC-induced cytotoxic effects in C2C12 myoblasts. These data reinforce the interest in edible oils associated with the Mediterranean diet, such as PLSO, in the prevention of age-related diseases, such as sarcopenia.

Impact of Oxysterols on Cell Death, Proliferation, and Differentiation Induction: Current Status.

Oxysterols are oxidized derivatives of cholesterol produced by enzymatic activity or non-enzymatic pathways (auto-oxidation). The oxidation processes lead to the synthesis of about 60 different oxysterols. Several oxysterols have physiological, pathophysiological, and pharmacological activities. The effects of oxysterols on cell death processes, especially apoptosis, autophagy, necrosis, and oxiapoptophagy, as well as their action on cell proliferation, are reviewed here. These effects, also observed in several cancer cell lines, could potentially be useful in cancer treatment. The effects of oxysterols on cell differentiation are also described. Among them, the properties of stimulating the osteogenic differentiation of mesenchymal stem cells while inhibiting adipogenic differentiation may be useful in regenerative medicine.

Nigella and Milk Thistle Seed Oils: Potential Cytoprotective Effects against 7ß-Hydroxycholesterol-Induced Toxicity on SH-SY5Y Cells.

Oxysterols are assumed to be the driving force behind numerous neurodegenerative diseases. In this work, we aimed to study the ability of 7ß-hydroxycholesterol (7ß-OHC) to trigger oxidative stress and cell death in human neuroblastoma cells (SH-SY5Y) then the capacity of Nigella sativa and Milk thistle seed oils (NSO and MTSO, respectively) to oppose 7ß-OHC-induced side effects. The impact of 7ß-OHC, associated or not with NSO or MTSO, was studied on different criteria: cell viability; redox status, and apoptosis. Oxidative stress was assessed through the intracellular reactive oxygen species (ROS) production, levels of enzymatic and non-enzymatic antioxidants, lipid, and protein oxidation products. Our results indicate that 7ß-OHC (40 µg/mL) exhibit pr-oxidative and pro-apoptotic activities shown by a decrease of the antioxidant enzymatic activities and an increase of ROS production, lipid, and protein oxidation end products as well as nitrotyrosine formation and caspase 3 activation. However, under the pre-treatment with NSO, and especially with MTSO (100 µg/mL), a marked attenuation of oxidative damages was observed. Our study suggests harmful effects of 7ß-OHC consisting of pro-oxidative, anti-proliferative, and pro-apoptotic activities that may contribute to neurodegeneration. NSO and especially MTSO showed potential cytoprotection against the cytotoxicity of 7ß-OHC.

7-Ketocholesterol: Effects on viral infections and hypothetical contribution in COVID-19.

7-Ketocholesterol, which is one of the earliest cholesterol oxidization products identified, is essentially formed by the auto-oxidation of cholesterol. In the body, 7-ketocholesterol is both provided by food and produced endogenously. This pro-oxidant and pro-inflammatory molecule, which can activate apoptosis and autophagy at high concentrations, is an abundant component of oxidized Low Density Lipoproteins. 7-Ketocholesterol appears to significantly contribute to the development of age-related diseases (cardiovascular diseases, age-related macular degeneration, and Alzheimer's disease), chronic inflammatory bowel diseases and to certain cancers. Recent studies have also shown that 7-ketocholesterol has anti-viral activities, including on SARS-CoV-2, which are, however, lower than those of oxysterols resulting from the oxidation of cholesterol on the side chain. Furthermore, 7-ketocholesterol is increased in the serum of moderately and severely affected COVID-19 patients. In the case of COVID-19, it can be assumed that the antiviral activity of 7-ketocholesterol could be counterbalanced by its toxic effects, including pro-oxidant, pro-inflammatory and pro-coagulant activities that might promote the induction of cell death in alveolar cells. It is therefore suggested that this oxysterol might be involved in the pathophysiology of COVID-19 by contributing to the acute respiratory distress syndrome and promoting a deleterious, even fatal outcome. Thus, 7-ketocholesterol could possibly constitute a lipid biomarker of COVID-19 outcome and counteracting its toxic effects with adjuvant therapies might have beneficial effects in COVID-19 patients.

Oxysterols and multiple sclerosis: Physiopathology, evolutive biomarkers and therapeutic strategy.

Multiple sclerosis is an autoimmune disease that affects the central nervous system. Dysfunction of the immune system leads to lesions that cause motor, sensory, cognitive, visual and/or sphincter disturbances. In the long term, these disorders can progress towards an irreversible handicap. The diagnosis takes time because there are no specific criteria to diagnose multiple sclerosis. To realize the diagnosis, a combination of clinical, biological, and radiological arguments is therefore required. Hence, there is a need to identify multiple sclerosis biomarkers. Some biomarkers target immunity through the detection of oligoclonal bands, the measurement of the IgG index and cytokines. During the physiopathological process, the blood-brain barrier can be broken, and this event can be identified by measuring metalloproteinase activity and diffusion of gadolinium in the brain by magnetic resonance imaging. Markers of demyelination and of astrocyte and microglial activity may also be of interest as well as markers of neuronal damage and mitochondrial status. The measurement of different lipids in the plasma and cerebrospinal fluid can also provide suitable information. These different lipids include fatty acids, fatty acid peroxidation products, phospholipids as well as oxidized derivatives of cholesterol (oxysterols). Oxysterols could constitute new biomarkers providing information on the form of multiple sclerosis, the outcome of the disease and the answer to treatment.

Maillard Reaction Products and Phenolic Compounds from Roasted Peanut Flour Extracts Prevent Scopolamine-Induced Amnesia Via Cholinergic Modulation and Antioxidative Effects in Mice.

Research on the beneficial effects of Maillard reaction products (MRPs) and phenolic compounds derived from roasted peanut flour on the nervous system remains insufficient. This study aimed to evaluate the effect of a 28-day oral administration of defatted peanut extract rich in MPRs and polyphenolic compounds on the cognitive impairments and oxidative injury induced by scopolamine in a mouse model. Light and dark extracts from peanut flour were prepared by heating peanuts at 187°C for two different times (8.6 and 12.7 min) and defatted using soxhlet apparatus. The mice were orally pretreated with either roasted defatted peanuts extracts (100 mg/kg) or donepezil (3 mg/kg) for 21 days. On day 19 and until day 28, mice were injected subcutaneously with water or scopolamine (1 mg/kg body weight) 15 min after roasted defatted peanuts extracts/water feeding. Mice were subsequently subjected to a battery of behavioral tests including open field locomotor activity assay, and Morris water maze test. Brain tissues were collected to measure acetylcholine, acetylcholinesterase, and oxidative parameters (glutathione and malondialdehyde). Roasted defatted peanuts (light and dark) (100 mg/kg) treatment significantly ameliorated cognitive performance and reversed the oxidative damage when compared with the scopolamine group. These data demonstrate the defatted peanuts extracts exert potent anti-amnesic effects via the modulation of cholinergic and antioxidant activities.

Oxiapoptophagy: A type of cell death induced by some oxysterols.

Oxysterols are oxidized forms of cholesterol generated from cholesterol by auto-oxidation, enzymatic processes, or both. Some of them (7-ketocholesterol, 7ß-hydroxycholesterol and 24(S)-hydroxycholesterol), when used at cytotoxic concentrations on different cell types from different species (mesenchymal bone marrow cells, monocytic cells and nerve cells), induce a type of cell death associated with OXIdative stress and several characteristics of APOPTOsis and autoPHAGY, defined as oxiapoptophagy. Oxidative stress is associated with overproduction of ROS, increased antioxidant enzyme activities, lipid peroxidation and protein carbonylation. Apoptosis is associated with activation of the mitochondrial pathway, opening of the mitochondrial permeability pore, loss of mitochondrial membrane potential, caspase-3 activation, PARP degradation, nuclear condensation and/or fragmentation. Autophagy is characterized by autophagic vacuoles revealed by monodansylcadaverine staining and transmission electron microscopy, plus increased ratio of LC-3II/LC-3I. In addition, morphological, topographical and functional changes of the peroxisome are observed. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.

Association Between Oxidative Stress and Altered Cholesterol Metabolism in Alzheimer's Disease Patients.

BACKGROUND: Oxidative stress is the main feature of several diseases including Alzheimer's disease (AD). The involvement of oxysterols derivates has been recently reported. OBJECTIVE: The aim of this study was to evaluate the implication of oxidative stress in cholesterol impairment in AD patients. METHODS: A case-control study was conducted on 56 AD patients and 97 controls. Levels of oxidative biomarkers, including lipid peroxidation products and antioxidant enzyme activities were measured with spectrophotometric methods on red blood cells (RBCs) and plasma. Cholesterol precursors and oxysterols (7-Ketocholeterol (7KC), 7α-hydroxycholesterol (7α-OHC), 7ß-hydroxycholesterol (7ß-OHC), 24Shydroxycholesterol (24S-OH), 25-hyroxycholesterol (25-OHC), and 27-hydroxycholesterol (27-OHC), in plasma were quantified by gas chromatography coupled with mass spectrometry. RESULTS: In RBCs and plasma of AD patients, a significant decrease of glutathione peroxidase (GPx) activity was detected associated with raised levels of malondialdehyde (MDA). A decreased level of lanosterol and an accumulation of 7ß-OHC, 24S-OHC, 27-OHC, and 25-OHC that were higher in plasma of AD patients, compared to controls, were also observed in AD patients. Mini-Mental State Examination (MMSE) score was correlated with MDA and conjugated dienes (CD) levels in plasma. Besides, the MDA level in RBCs was correlated with 7ß-OHC. Binary logistic regression revealed an association between GPx activity and AD (OR=0.895, 95%CI: 0.848-0.945. P<0.001). CONCLUSION: Our data consolidate the relationship between the rupture of redox homeostasis and lipid and cholesterol oxidation in AD.

Evaluation of pro-inflammatory cytokines in frail Tunisian older adults.

The present study was undertaken to evaluate serum levels of pro-inflammatory cytokines in Tunisian older adults and to examine the relationships between inflammatory marker levels, geriatric, and biochemical parameters. A cross-sectional study was conducted in a population of Tunisian older adults (N = 141, aged 65 and over). Patients were recruited from the Department of Internal Medicine, Fattouma Bourguiba University Hospital (Monastir, Tunisia) and from a nursing home (Sousse, Tunisia). Comprehensive geriatric assessment, history taking and examination including functional and nutritional assessment were done for each participant. Enzyme-linked immunosorbent assay (ELISA) test was used to measure serum cytokine (TNF-α, IL-8, IL-6) levels. The modified Short Emergency Geriatric Assessment score (SEGAm) were used to classify patients as 51 very-frail, 40 frail, and 50 non-frail. The age of the participants (80 men, 61 women) ranged from 65 to 97 years. Serum levels of TNF-α, IL-8 and C-reactive protein (CRP) were significantly higher in very-frail participants compared to frail and non-frail ones. However, no significant differences in IL-6 levels were detected among frailty groups. After adjustment for age, CRP and IL-8 levels remained significantly associated with frailty. Analysis of the receiver operating characteristic (ROC) curve corresponding to IL-8 showed an area under the curve of 0.7 (p = 0.003; 95% CI [0.58-0.81]) and a predictive threshold of 5.27 pg/ml. Positive correlations were found between frailty score, IL-6, and IL-8 levels. In addition, a significant positive correlation was observed between IL-8 levels and Timed Up and Go test results. However, a negative correlation was observed between Mini Nutritional Assessment Short-Form score, IL-6 and CRP levels, as well as between Activities of Daily Living score and serum levels of TNF-α, IL-6, and CRP. In conclusion, the key findings of this study collectively support a role of pro-inflammatory cytokines, TNF-α, CRP, and especially IL-8 in the development of frailty in older adults.

Prevention by Dietary Polyphenols (Resveratrol, Quercetin, Apigenin) Against 7-Ketocholesterol-Induced Oxiapoptophagy in Neuronal N2a Cells: Potential Interest for the Treatment of Neurodegenerative and Age-Related Diseases.

The Mediterranean diet is associated with health benefits due to bioactive compounds such as polyphenols. The biological activities of three polyphenols (quercetin (QCT), resveratrol (RSV), apigenin (API)) were evaluated in mouse neuronal N2a cells in the presence of 7-ketocholesterol (7KC), a major cholesterol oxidation product increased in patients with age-related diseases, including neurodegenerative disorders. In N2a cells, 7KC (50 µM; 48 h) induces cytotoxic effects characterized by an induction of cell death. When associated with RSV, QCT and API (3.125; 6.25 µM), 7KC-induced toxicity was reduced. The ability of QCT, RSV and API to prevent 7KC-induced oxidative stress was characterized by a decrease in reactive oxygen species (ROS) production in whole cells and at the mitochondrial level; by an attenuation of the increase in the level and activity of catalase; by attenuating the decrease in the expression, level and activity of glutathione peroxidase 1 (GPx1); by normalizing the expression, level and activity of superoxide dismutases 1 and 2 (SOD1, SOD2); and by reducing the decrease in the expression of nuclear erythroid 2-like factor 2 (Nrf2) which regulates antioxidant genes. QCT, RSV and API also prevented mitochondrial dysfunction in 7KC-treated cells by counteracting the loss of mitochondrial membrane potential (ΨΔm) and attenuating the decreased gene expression and/or protein level of AMP-activated protein kinase α (AMPKα), sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) implicated in mitochondrial biogenesis. At the peroxisomal level, QCT, RSV and API prevented the impact of 7KC by counteracting the decrease in ATP binding cassette subfamily D member (ABCD)3 (a peroxisomal mass marker) at the protein and mRNA levels, as well as the decreased expresssion of genes associated with peroxisomal biogenesis (Pex13, Pex14) and peroxisomal ß-oxidation (Abcd1, Acox1, Mfp2, Thiolase A). The 7KC-induced decrease in ABCD1 and multifunctional enzyme type 2 (MFP2), two proteins involved in peroxisomal ß-oxidation, was also attenuated by RSV, QCT and API. 7KC-induced cell death, which has characteristics of apoptosis (cells with fragmented and/or condensed nuclei; cleaved caspase-3; Poly(ADP-ribose) polymerase (PARP) fragmentation) and autophagy (cells with monodansyl cadaverine positive vacuoles; activation of microtubule associated protein 1 light chain 3-I (LC3-I) to LC3-II, was also strongly attenuated by RSV, QCT and API. Thus, in N2a cells, 7KC induces a mode of cell death by oxiapoptophagy, including criteria of OXIdative stress, APOPTOsis and autoPHAGY, associated with mitochondrial and peroxisomal dysfunction, which is counteracted by RSV, QCT, and API reinforcing the interest for these polyphenols in prevention of diseases associated with increased 7KC levels.