Amira Zarrouk

University of Monastir | UTM · Department of Biochemistry, Research Laboratory LR-NAFS ‘Nutrition - Functional Food & Vascular Health’.

Light and dark peanut meal extracts were prepared by roasting peanuts at 187 °C for 8.6 and 12.7 minutes. The peanuts were then defatted and extracted with a mixture of ethanol-water. An increase of total phenolic compounds was observed, with a significant increase of the absorbance at 294 and 420 nm, the fluorescence intensity as well as the total...

Anthocyanins are water-soluble pigments contained in numerous food plants. This study provides an overall quantitative literature analysis on anthocyanins. Bibliometric data were collected through the search string TOPIC = anthocyan*, which yielded 44,121 publications indexed within the Web of Science Core Collection. Term maps were generated using...

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). Oxidat...

Phytosterols, which are produced in plants, are structurally similar to cholesterol. Their basic structures consist of a cyclo pentano-perhydrophenanthrene nucleus composed of 3 hexane rings and of a pentane ring with an alkyl side chain. There are around more than 250 phytosterols and related compounds that have been identified in natural resource...

Oxysterols, resulting from the oxidation of cholesterol, are formed either by autoxidation, enzymatically, or by both processes. These molecules, which are provided in more or less important quantities depending on the type of diet, are also formed in the body and their presence is associated with a normal physiological activity. Their increase and...

7-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 asso...

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 reduc...

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 inflammatio...

Background The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled “International Natural Product Sciences Taskforce” (INPST) was established in 2018, to bring...

Polyphenols are natural antioxidant molecules. They are present in several compounds, mainly fruits and vegetable, of the Mediterranean diet and have benefits on human health. Several studies support that they delay the aging process and prevent age-related diseases. However, as polyphenols are rapidly metabolized, their in vivo efficiency can be l...

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...

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 [...]

Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to brin...

Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled “International Natural Product Sciences Taskforce” (INPST) was established in 2018, to brin...

The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled “International Natural Product Sciences Taskforce” (INPST) was established in 2018, to bring together i...

7-ketocholesterol and 7β-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 civili...

7-Ketocholesterol (or 7-oxocholesterol) is an oxysterol essentially formed by cholesterol autoxidation. It is often found at enhanced levels in the body fluids and/or target tissues of patients with age-related diseases (cardiovascular, neuronal, and ocular diseases) as well as in subjects concerned with civilization diseases (type 2 diabetes, bowe...

Background Aging is accompanied by a progressive decline in physical activity due to a loss of skeletal muscle mass and strength considered as a geriatric characteristic defined as sarcopenia. This latter may be associated with joint damage, all of which may predispose older people to the risk of falls. Few evidences suggest that oxidative stress p...

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 o...

Peroxisomes 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...

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 clarific...

Citation: Kessas, K.; Chouari, Z.; Ghzaiel, I.; Zarrouk, A.; Ksila, M.; Ghrairi, T.; El Midaoui, A.; Lizard, G.; Kharoubi, O. Role of Bioactive Compounds in the Regulation of Mitochondrial Dysfunctions in Brain and Age-Related Neurodegenerative Diseases. Cells 2022, 11, 257. https://

Aging is characterized by a progressive increase in oxidative stress, which favors lipid peroxidation and the formation of cholesterol oxide derivatives, including 7β-hydroxycholesterol (7β-OHC). This oxysterol, which is known to trigger oxidative stress, inflammation, and cell death, could contribute to the aging process and age-related diseases,...

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, es...

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,...

Oxysterols are assumed to be the driving force behind numerous neurodegenerative diseases. In this work, we aimed to study the ability of 7β-hydroxycholesterol (7β-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 oppos...

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 cri...

Age-related diseases for which there are no effective treatments include cardiovascular diseases; neurodegenerative diseases such as Alzheimer's disease; eye disorders such as cataract and age-related macular degeneration; and, more recently, Severe Acute Respiratory Syndrome (SARS-CoV-2). These diseases are associated with plasma and/or tissue inc...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

Herein we report the synthesis of peptide-like and tetrazole-based organoselenium compounds via Ugi and Ugi-azide reactions, respectively. The organoselenium compounds' intrinsic cytoprotective and antioxidant capacities were evaluated in 158N and 158JP murine oligodendrocytes. Furthermore, their redox properties were theoretically evaluated using...

Keywords: Fatty acid desaturase 1 (FADS1) Fatty acid desaturase 2 (FADS2) Elongation of very-long-chain fatty acids-like 2 (ELOVL2) Single nucleotide polymorphism (SNP) Alzheimer's disease (AD) polyunsaturated fatty acids (PUFAs) Arachidonic acid (AA) A B S T R A C T Polyunsaturated fatty acids (PUFAs) are closely related to various physiological c...

the PDF can be download freely on pubmed. https://pubmed.ncbi.nlm.nih.gov/33634751/

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

Objective Oxidative stress is the main feature of several diseases including Alzheimer’s disease (AD). The involvement of oxysterols derivates has been recently reported. In this study, the implication of oxidative stress in cholesterol impairment in AD patients will be evaluated. Methods A case-control study was conducted on 56 AD patients and 97...

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 recruit...

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 patien...

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 oxida...

Oxysterols are oxidized forms of cholesterol generated from cholesterol by auto‐oxidation, enzymatic processes, or both. Some of them (7‐ketocholesterol, 7β‐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...

Although bioactivities of Olea europaea (OE) have been widely described, most of them were related to its methanolic extracts or its essential oils, While data related to aqueous extracts still very scarce. Thus, in this study, the phytochemical composition, the antioxidant activity, the cytotoxic potential, and the allelopathic potential of aqueou...

Background: Frailty is a multidimensional syndrome that leads to an increase of an age-related disorder of several physiological systems, and cognitive abilities decline. The aim of this study was to evaluate the prevalence of frailty among older persons in Belgium and we examined the factors associated with frailty with a principal focus en cogni...

Background: Frailty is a multidimensional syndrome that leads to an increase of an age-related disorder of several physiological systems, and cognitive abilities decline. The aim of this study was to evaluate the prevalence of frailty among older persons in Belgium and we examined the factors associated with frailty with a principal focus en cognit...

Argan, olive, and milk thistle seed oils are characterized by high levels of tocopherols, mainly α-tocopherol. They are also rich in oleic acid (C18:1 n-9) and linoleic acid (C18:2 n-6) and contain small quantities of several polyphenols. As tocopherols and polyphenols have antioxidant properties and are able to cross the blood-brain barrier, it is...

Peroxisomopathies are qualitative or quantitative deficiencies in peroxisomes which lead to increases in the level of very-long-chain fatty acids (VLCFA) and can be associated with more or less pronounced dysfunction of central nervous system cells: glial and microglial cells. Currently, in frequent neurodegenerative diseases, Alzheimer’s disease (...

Peroxisomopathies are rare diseases due to dysfunctions of the peroxisome in which this organelle is either absent or with impaired activities. These diseases, at the exception of type I hyperoxaluria and acatalasaemia, affect the central and peripheral nervous system. Due to the significant impact of peroxisomal abnormalities on the functioning of...

T. capitatus is widely used in traditional medicine in Tunisia. The main goal of this study was to evaluate the phytochemical composition, the fatty acids profile, the antioxidant, antibacterial, and antifungal activities as well as the cytotoxic potential of the essential oil (EO) of this plant. The identification and the quantification of the dif...

To prevent neurodegeneration associated to aging or observed in numerous neurodegenerative diseases, it can be of interest to favor neuronal differentiation of immature and pluripotent stem cells. ODN, produced by astrocytes, is an endozepine generated through the proteolytic cleavage of the diazepam binding inhibitor (DBI). ODN stimulates neurogen...

Oxysterols are molecules derived by the oxidation of cholesterol and can be formed either by auto-oxidation, enzymatically or by both processes. Among the oxysterols formed by auto-oxidation, 7-ketocholesterol and 7β-hydroxycholesterol are the main forms generated. These oxysterols, formed endogenously and brought in large quantities by certain foo...

Background Frailty is a multidimensional syndrome that leads to an increase of an age-related disorder of several physiological systems, and cognitive abilities decline. The aim of this study was to evaluate the prevalence of frailty among older persons in Belgium and we examined the factors associated with frailty with a principal focus en cogniti...

Background : Frailty is a multidimensional syndrome that leads to an increase of an age-related disorder of several physiological systems, and cognitive abilities decline. The aim of this study was to evaluate the prevalence of frailty among older persons in Belgium and we examined the factors associated with frailty with a principal focus en cogni...

Background The effects of vegetable oils on human health depends on their components. Therefore, their profiles of lipid nutrients were determined. Objective To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO;...

Oxidative stress and mitochondrial dysfunction contribute to the pathogenesis of neurodegenerative diseases and favor lipid peroxidation, leading to increased levels of 7β-hydroxycholesterol (7β-OHC) which induces oxiapoptophagy (OXIdative stress, APOPTOsis, autoPHAGY). The cytoprotective effects of dimethylfumarate (DMF), used in the treatment of...

Mitochondrial dysfunction and oxidative stress are involved in neurodegenerative diseases associated with an enhancement of lipid peroxidation products such as 7β- hydroxycholesterol (7β-OHC). It is therefore important to study the ability of 7β-OHC to trigger mitochondrial defects, oxidative stress, metabolic dysfunctions and cell death, which are...

Objective: Age-related diseases, including neurodegenerative diseases, are associated with oxidative stress and lipid peroxidation, and increase the levels of cholesterol auto-oxidation products such as 7β-hydroxycholesterol (7β-OHC). Thus, it is imperative to identify agents that can prevent 7β-OHC-induced side-effects. Methods: We evaluated th...

The present study consisted in evaluating the antioxidant, anti-inflammatory and cytoprotective properties of ethanolic extracts from three mint species (Mentha spicata L. (MS), Mentha pulegium L. (MP) and Mentha rotundifolia (L.) Huds (MR)) with biochemical methods on murine RAW 264.7 macrophages (a transformed macrophage cell line isolated from a...

The Asteraceae family is economically very important, because many of these plants are grown mainly for their food value, such as lettuce (Lactuca), chicory (Cichorium), and sunflower (Heliantus aminus). One of the typical properties of this family, which includes milk thistle (Sylibum marianum), is the richness of the oil in various compounds (fla...

Cholesterol oxidation products, also named oxysterols, can be formed either by cholesterol auto-oxidation, enzymatically or both. Among these oxysterols, 7-ketocholesterol (7KC) is mainly formed during radical attacks that take place on the carbon 7 of cholesterol. As increased levels of 7KC have been found in the tissues, plasma and/or cerebrospin...

Some oxysterols resulting either from enzymatic oxidation or autoxidation of cholesterol are associated with age-related diseases including neurodegenerative diseases. Among these oxysterols, 7β-hydroxycholesterol (7β-OHC) is often found at increased levels in patients. It is therefore important to identify molecules or mixtures of molecules to pre...

The involvement of organelles in cell death is well established especially for endoplasmic reticulum, lysosomes and mitochondria. However, the role of the peroxisome is not well known, though peroxisomal dysfunction favors a rupture of redox equilibrium. To study the role of peroxisomes in cell death, 158 N murine oligodendrocytes were treated with...

In the coming years, age-related diseases will increase. These diseases mainly include cardiovascular diseases, neurodegenerative diseases, ocular diseases (cataract, age-related macular degeneration), type-2 and-3 diabetes, inflammatory diseases of the joints and intestines, osteoporosis and some cancers. In these diseases, the role of lipids (sat...

Here a new series of twenty-one organoselenides, of potential protective activity, were synthesized and tested for their intrinsic cytotoxicity, anti-apoptotic and antioxidant capacities in oligodendrocytes. Most of the organoselenides were able to decrease the ROS levels, revealing antioxidant properties. Compounds 5b and 7b showed a high glutathi...

The propagation of nerve impulses in myelinated nerve fibers depends on a number of factors involving the myelin and neural axons. In several neurodegenerative diseases, nerve impulses can be affected by the structural and biochemical characteristics of the myelin sheath and the activity of ion channels located in the nodes of Ranvier. Though it is...

Background: Nutritional choices, which include the source of dietary fatty acids (FA), have an important significant impact on coronary artery disease (CAD). We aimed to determine on patients with CAD the relationships between Trans fatty acids (Trans FA) and different CAD associated parameters such as inflammatory and oxidative stress parameters...

Little is known about K+regulation playing major roles in the propagation of nerve impulses, as well as in apoptosis and inflammasome activation involved in neurodegeneration. As increased levels of 7-ketocholesterol (7KC), 24S-hydroxycholesterol (24S-OHC) and tetracosanoic acid (C24:0) have been observed in patients with neurodegenerative diseases...

Argan oil is widely used in Morocco in traditional medicine. Its ability to treat cardiovascular diseases is well-established. However, nothing is known about its effects on neurodegenerative diseases, which are often associated with increased oxidative stress leading to lipid peroxidation and the formation of 7-ketocholesterol (7KC) resulting from...

Background Some factors related to diet are known to be involved in the progression of atherosclerosis in humans. Methods The relationship between plasma fatty acid (FA) levels and the severity of coronary artery disease (CAD), evaluated by Gensini score (GS), was investigated in CAD Tunisian patients compared to controls. Lipid profiles were anal...