Amri Mohamed

Tunis El Manar University | FST · Biology

Mode de présentation : Orale. Champ disciplinaire : physiologie du sport de l'exercice et entrainement sportif Titre : Effets de la flexibilité combinée à des exercices plyométriques par rapport à un mode plyométrique ou de flexibilité isolée chez des adolescents masculins pratiquant la course de haies. Résumé : L'étude vise à déterminer l'effet d'...

Background and Objective: Pesticides exposure has been reported as an environmental factor that increases the risk of developing serious health problems. Glyphosate is one of the most widely used pesticides in the world. In the present work, in vivo biochemical and histological study of the hepatotoxic effect of glyphosate on liver rats has been fi...

Glyphosate, the active substance in Roundup®, is the most widely used pesticide in the world and may be present as a residue in derived foods and drinking water. leaves are a source of phenolic compounds and can be a good start towards discovering a new chemical compound which may lead to a new drug. Renoprotective effects of M. alba extract and it...

Glyphosate, the active substance in Roundup®, is the most widely used pesticide in the world and may be present as a residue in derived foods and drinking water. Previous reports have confirmed that extracts from leaves of Morus alba exert many pharmacological activities. However, renoprotective effects of M. alba extract and its underling molec...

Allium sativum (As), commonly known as garlic, has been used for a long time, for its therapeutic effects. Recent studies showed the ability of As to modulate vascular activity. The present study aimed to investigate the vasomodulatory effects of aqueous extract of As and to analyse the molecular nature of the active components. Experiments were pe...

rôle du gène pallidin dans la régulation du cycle éveil/sommeil.

Introduction : Cadmium (Cd) is a toxic heavy metal used in various industrial applications and therefore can cause, both by environmental or professional exposure, several damage in all body systems. The present study was developed to determine the toxic effect of high dose of Cd on the rat's liver as well as the putative protective effect of vitam...

Aluminum (Al) is recognized potent neurotoxic metal, which causes oxidative stress leading to intracellular accumulation of reactive oxygen species (ROS) and neuronal cell death in various neurodegenerative diseases. Among several medicinal plants with beneficial effects on health, curcumin acts as a multi-functional drug with antioxidant activity....

Opuntia species are utilized as local medicinal interventions for chronic diseases and as food sources mainly because they possess nutritional properties and biological activities. This study aimed to disclose the phytochemical composition, anti-oxidant potential, and antimicrobial activity of two extracts recovered from Opuntia streptacantha fruit...

Although progress has been made to show the role of raw flaxseed and flaxseed extracts in health promotion, identification of mechanism(s) of action and molecule(s) underpinning beneficial effects largely remain unknown. The present study evaluated the efficacy of an aqueous flaxseed extract (AFE) to correct alloxan-induced diabetes in mice. Mice w...

In traditional medicine extracts of plants (Cactus) are widely employed for the treatment of skin, epithelium wounds and mucous membrane irritation. Photo-induced dermatosis is the result of the harmful effect of UV irradiations on the skin. The aim of this study was to clarify whether O. streptacantha cladodes has a curative effect against the irr...

Background: This study aims to determine the effect of flexibility exercises combined with plyometrics in hurdles race, on physical fitness, motor skills (MS) and hip range of motion. Methods: 34 male hurdlers, (age = 15.7±0.7 years, body mass = 59.7±2.3 kg, height = 170.8±2.4 cm) were randomly assigned to four independent groups. The (Gflex+ply...

Oxidative stress, associated with various neurodegenerative diseases, promotes ROS generation, impairs cellular antioxidant defenses, and finally, triggers both neurons and astroglial cell death by apoptosis. Astrocytes specifically synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide (ODN). We hav...

Parkinson’s disease is a neurodegenerative disorder characterized by the progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta, and it involves oxidative stress. Our goal was to evaluate the neuroprotective effect of Vitis vinifera red grape seed and skin extract (GSSE) in a model of Parkinson’s disease. GSSE...

Introduction : Cadmium (Cd) is a toxic heavy metal used in various industrial applications and therefore can cause, both by environmental or professional exposure, several damage in all body systems. The present study was developed to determine the toxic effect of high dose of Cd on the rat’s liver as well as the putative protective effect of vitam...

Diarrhea pathophysiology and constipation are multifactorial gastrointestinal (GI) disorders characterized by intestinal peristalsis disruption of and an irregularity in secretion/absorption process. Oxidative stress, as an imbalance in prooxidants/antioxidants, has recently been recognized as a significant player in these GI disturbances. In this...

The term endozepines designates a family of astroglia-secreted proteins including the diazepam-binding inhibitor (DBI) and its processing products, which have been originally isolated and characterized as endogenous ligands of benzodiazepine receptors. It is now clearly established that the octadecaneuropeptide ODN (DBI33-50), acting through the ce...

In the CNS, including the optic nerve, oligodendrocytes play a critical role in the myelination of axons. Oligodendrocytes are exceptionally sensitive to insults to the CNS, such as injury, ischemia, or inflammation, which result in the loss of oligodendrocytes and myelin and eventually secondary axon degeneration. Oligodendrocytes are sensitive to...

Amino-acid transporters are involved in functions reportedly linked to the sleep/wake cycle: neurotransmitter synthesis and recycling, the regulation of synaptic strength, protein synthesis and energy metabolism. In addition, the existence of bidirectional relationships between extracellular content, transport systems and sleep/wake states is recei...

This study was conducted to compare the effects of juice and seeds on gastric emptying, small-bowel motility and intestinal ion transport. Separate groups of rats were randomized to receive NaCl, increasing doses of juice (5, 10, and 20 mL/kg, b.w.) or seeds aqueous extract (100, 200, and 400 mg/kg, b.w.). Simultaneously, two other groups were rece...

Context: Methotrexate (MTX) is a cytotoxic chemotherapeutic element for various inflammatory diseases. The cytotoxic effect of MTX is also seen in normal tissues having a high proliferation rate including gastrointestinal and bone marrow. Aims: The aim of this study was to find out whether oxidative damage could be relevant for MTX-induced toxic...

In the CNS, including the optic nerve, oligodendrocytes play a critical role in the myelination of axons. Oligodendrocytes are exceptionally sensitive to insults to the CNS, such as injury, ischemia, or inflammation, which result in the loss of oligodendrocytes and myelin and eventually secondary axon degeneration. Oligodendrocytes are sensitive to...

Amino-acid transporters are involved in functions reportedly linked to the sleep/wake cycle: neurotransmitter synthesis and recycling, the regulation of synaptic strength, protein synthesis and energy metabolism. In addition, the existence of bidirectional relationships between extracellular content, transport systems and sleep/wake states is recei...

Extracellular activity of swallowing neurons (SN) in the region of the hypoglossal (XIIth) motor nucleus was studied in sheep anesthetized with halothane. Eighty six SN exhibited a discharge closely linked to swallowing electromyographic (EMG) activity of the geniohyoïd (GH) muscle induced by stimulation of the superior laryngeal nerve. Swallowing...

We investigated in sheep the effects of stimulation of the thick afferent fibers running through the lingual nerve (LN) upon the activity of some of the muscles and medullary interneurons or motoneurons which are active during swallowing. Using electromyography (EMG), and extra- and intracellular neuronal recording, we demonstrated that LN stimulat...

The nervous mechanisms that generate swallowing are still largely unknown. It has been suggested that a central pattern generator that contains a serial network of linked neurons must produce the successive excitation of motoneurons (Mns) and then the sequential activation of muscle through excitatory connections. Inhibitory connections have also b...

Neurons of the hypoglossal (XIIth) motor nucleus participate in swallowing, but nothing is known of the input to these cells from swallowing interneurons (SIN) belonging to the medullary swallowing center (SC). After electrophoretic injection of horseradish peroxidase within the XIIth motor nucleus in sheep, labeled neurons were found principally i...

The anatomical connections between two regions involved in swallowing, the medullary reticular formation around the nucleus ambiguous (ventral group of swallowing interneurons) and the trigeminal motor nucleus (NMV) were studied in sheep using anterograde and retrograde tracing techniques. [3H]leucine and HRP were injected into the ventral medulla...

The participation of extrinsic muscles of the tongue in swallowing reflexly induced by stimulation of the superior laryngeal nerve was studied in 7 anesthetized sheep. The tongue retractor muscles (styoglossus and hyyoglossus) always discharged in synergy with the suprahyoid (geniohyoid) and jaw (anterior digastric medial pterygoid) muscles. The ma...

The origin of the inputs from the medullary swallowing centre (dorsal region including the nucleus of the solitary tract, or ventral region corresponding to the reticular formation surrounding the nucleus ambigous) to the pontine swallowing neurones (PSNs) was studied in sheep anaesthetized with halothane. Out of 101 PSNs located in the posterior p...

The projections of ventral medullary reticular neurons on both trigeminal (Vth) and hypoglossal (XIIth) motor nucleus were studied in sheep anesthetized with halothane. In a first series of experiments, extracellular microelectrodes were used to record the activity of medullary swallowing interneurons (SINs) located in the ventral region (around th...

This study focuses on motoneurons and interneurons in the region of the hypoglossal nucleus (XIIth) related to swallowing and chewing. In sheep anesthetized with halothane, we have used extracellular microelectrodes to study the effects of stimulation of the superior laryngeal nerve (SLN), the lingual nerve (LN) and the chewing cortex (CCx) upon ac...

Extracellular activity of swallowing neurons (SN) in the region of the hypoglossal (XIIth) motor nucleus was studied in sheep anesthetized with halothane. Eighty six SN exhibited a discharge closely linked to swallowing electromyographic (EMG) activity of the geniohyoïd (GH) muscle induced by stimulation of the superior laryngeal nerve. Swallowing...

Mastication and swallowing are two tightly integrated components of food intake behavior. We investigated the effects of stimulating the chewing area of the fronto-orbital cortex (CCx) on some muscles and medullary interneurons (Ins) or motoneurons (Mns) active during swallowing. For the purpose of comparison, the lingual nerve (LN) was also stimul...

Chez le mouton anesthésié (fluothane), nous avons étudié l'activité du réseau neuronique pontique actif lors de déglutitions déclenchées par stimulation du nerf laryngé supérieur ou de la région du faisceau solitaire bulbaire (courtes salves de chocs à 30 Hz ou à 500 Hz). L'enregistrement de l'activité électromyographique (EMG) des muscles innervé...

Chez le mouton anesthésié (Fluothane), nous avons étudié les effets de la stimulation d'afférences périphériques (nerfs laryngé supérieur, lingual et alvéolaire) et du cortex fronto-orbitaire (zones déglutitrice et masticatrice) sur l'activité unitaire des neurones pontiques actifs lors de la déglutition (voir Car et Amri 1982). Les neurones déglu...

Aims: The term angiogenesis refers to sprouting of new blood vessels from pre-existing ones. The angiogenic process involves cell migration and tubulogenesis requiring interaction between endothelial cells and the extracellular matrix. Human peroxidasin 1 (hsPxd01) is a multidomain heme peroxidase found embedded in the basement membranes. As it pr...

Astroglial cells are important actors in the defense of brain against oxidative stress injuries. Glial cells synthesize and release the octadecaneuropeptide ODN, a diazepam-binding inhibitor (DBI)-related peptide, which acts through its metabotropic receptor to protect neurons and astrocytes from oxidative stress-induced apoptosis. The purpose of t...

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by a progressive loss of dopamine (DA) neurons through apoptotic, inflammatory and oxidative stress mechanisms. The octadecaneuropeptide (ODN) is a diazepam-binding inhibitor (DBI)-derived peptide, expressed by astrocytes, which protects neurons against oxidative cell damages an...

Ethnopharmacological relevance: Ficus carica fruit, a source of bioactive functional ingredients, have been traditionally long time used for its medicinal benefits as they improve the digestive system, treating constipation and used as a natural laxative. Aim of the study: The recent study was investigated the ameliorative effect of Ficus carica...

The phytochemical composition and the effect of the green and ripe Opuntia ficus-indica juice on some gastrointestinal (GI) physiological parameters such as stomach emptying and small-intestinal motility and permeability were determined in rats administered multiple concentrations of the prickly pear juice (5, 10, and 20 mL kg-1, b.w., p.o.). Other...

In this study, we investigated the glioprotective effects of grape seed and skin supplement (GSSS) on potential cigarette smoke-induced cell death. For all gestational period, rats received GSSS as a food supplement at a rate of 100 mg/Kg. Newborn rats were weighed 24 h after birth and then cerebral hemispheres were collected for astrocyte culture....

Oxidative stress, associated with various neurodegenerative diseases, induces imbalance in ROS generation, impairs cellular antioxidant defences and finally triggers both neurons and astroglial cell death by apoptosis. Astrocytes specifically synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide (OD...

Le Cadmium (Cd) est un métal lourd toxique utilisé dans plusieurs applications industrielles et peut causer plusieurs dégâts dans l’organisme suite à l'exposition environnementale ou professionnelle. L’α-tocophérol est la forme la plus active de la vitamine E connue par ses propriétés anti-radicalaires. Ce travail a été élaboré afin de déterminer l...

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by a progressive loss of dopamine (DA) neurons through apoptotic, infammatory and oxidative stress mechanisms. The octadecaneuropeptide (ODN) is a diazepam-binding inhibitor (DBI)-derived peptide, expressed by astrocytes, which protects neurons against oxidative cell damages and...

The present study has been designed to explore the molecular mechanism and signaling pathway targets of chlorogenic acid (CGA) and its main hydrolysates, caffeic (CA) and quinic acid in the protective effect against glutamate-excitotoxicity. For this purpose 8-DIV cortical neurons in primary culture were exposed to 50 μM l-glutamic acid plus 10 µM...

Aim To investigate the effects of 3-month-long specific training program on biochemical status, oxidative and antioxidant responses in elite karatekas. Methods Twenty male karatekas [BMI: 21.9 ± 2.4 (kg/m ² )] participated in this study. They performed a 3-month specific training to prepare for an international competition. We measured selected bi...

Aim To investigate the effects of 3-month-long specific training program on biochemical status, oxidative and antioxidant responses in elite karatekas. Methods Twenty male karatekas [BMI: 21.9 ± 2.4 (kg/m2)] participated in this study. They performed a 3-month specific training to prepare for an international competition. We measured selected bioch...

This study was designed to examine the contribution of oxidative stress in gastrointestinal disorders after an intraperitoneal administration of 5 fluorouracil (5-FU; 100 mg/kg of body weight (b.w.)) and capecitabine oral administration (500 mg/kg b.w.). The animals were divided into three groups: Group A (NaCl,10 ml/kg of b.w.) considered as contr...

This study was conducted to compare the effects of juice and seeds on gastric emptying, small-bowel motility and intestinal ion transport. Separate groups of rats were randomized to receive NaCl, increasing doses of juice (5, 10, and 20 mL/kg, b.w.) or seeds aqueous extract (100, 200, and 400 mg/kg, b.w.). Simultaneously, two other groups were rece...

Introduction: Several research studies have reported on the pharmacological relevance of the medicinal plants used for treating various gastrointestinal disorders and controlling the dietary glucose uptake in the intestinal tract. Methods: Male rats were used to investigate the pharmacological effects of green oak acorn aqueous extract (GOAE) on...

Available online xxxx Edited by V Ördög The antioxidant potential of the ethanolic precipitate (EP) of the marine green alga Ulva rigida was evaluated via its scavenging ability on 1, 1-dipheny-2-picrylhydrazyl (DPPH) and cytoprotection against H 2 O 2-induced damage in yeast cells and zebrafish embryos. The EP exhibited substantially stronger DPPH...

Carob tree, Ceratonia siliqua L., is a medicinal plant used in Tunisian traditional medicine for the treatment of the gastro-intestinal (GI) disorders. In this respect, a relatively large number of scientific publications on the carob tree have been published in recent years. Therefore, the present review was aimed to analyze the traditional uses,...

Diarrhea pathophysiology and constipation are multifactorial gastrointestinal (GI) disorders characterized by intestinal peristalsis disruption of and an irregularity in secretion/absorption process. Oxidative stress, as an imbalance in prooxidants/antioxidants, has recently been recognized as a significant player in these GI disturbances. In this...

Irinotecan, a chemotherapy drug, can cause acute diarrhea immediately after administration. Hence, the present study was designed to investigate the gastrointestinal (GI) disturbances after an intraperitoneal (IP) administration of irinotecan in rats.Twenty Wistar rats were separated into two groups of ten. Group A was considered as a control group...

The purpose of this study is to examine the gastrointestinal disorders after injection of vinblastine (2mgkg⁻¹b.w. i.v.) in rats. Animals were divided into two equal groups: Group 1 was considered as a control group (NaCl, 0.9%). Group 2 was treated with intravenous injection of vinblastine for 7 days. Loperamide (2mgkg⁻¹) was injected in a saline...

Cadmium (Cd) accumulates in the brain and can damage neurons via complex processes involving oxidative stress induction. In this study we used a homogenous population of neurons which are cerebellar granule neurons (CGNs) to investigate damage induced by Cd and its effects on antioxidant enzyme activity. The exposure of CGNs to increasing concentra...

Oxidative stress plays a major role in triggering astroglial cell death in diverse neuropathological conditions such as ischemia and neurodegenerative diseases. Numerous studies indicate that hemoglobin (Hb) is expressed in both resting and reactive glia cells, but nothing is known regarding a possible role of Hb on astroglial cell survival. Thus,...

Recent studies demonstrate that glyphosate exposure is associated with oxidative stress and some neurological disorders such as Parkinson’s pathology. Therefore, phytochemicals, in particular phenolic compounds, have attracted increasing attention as potential agents for neuroprotection. In the present study, we investigate the impact of glyphosate...

Objectif Nous avons mis en évidence pallidin, un gène différentiellement exprimé chez un modèle de souris narcoleptiques, déficientes à la fois pour l’histamine et l’orexine (Souris HO−/−) et utilisé la drosophile pour tester la fonction de ce gène. Méthodes Chez la drosophile le sommeil a été évalué par un système de détection de la locomotion Tr...

In recent years, the obesity epidemic has developed into a major health crisis worldwide. With current treatments limited to expensive, high-risk surgery and minimally efficacious pharmacotherapy, new therapeutic options are urgently needed to fight against this alarming trend. Though brain dysfunction has been studied linked to high fat diet (HFD)...

Natural molecules from different origins exhibit high therapeutic potential. Among them, molecules from marine algae are of particular interest. In the present study, we investigated the preventive effect of a protein extract (PE) of Ulva rigida against UVB-induced cellular damages. We demonstrated that a treatment of cortical astrocytes with 50 μg...

In the present study, we investigated the effect of grape seed and skin supplement (GSSS), on lactating dairy ewes’ production. Ten dairy pregnant ewes from northern Tunisia were allocated to two groups: control diet (C) and supplemented with 20 % (w/w) GSSS. The experiment lasted for 8 weeks and took place after 2 months of lambing. During the exp...

ROS are involved in aging, progressive neuronal death, and age related disorders. During the last decade, there is increasing evidence indicating the beneficial role plant rich phytochemicals for the treatment of oxidative stress-induced disorders in the brain due to their antioxidant activity. Mulberry extract has been reported to have antioxidant...