Search results for "oxydant"
showing 10 items of 27 documents
Potential of the EPA/DHA 6/1 formulation to prevent endothelial dysfunction and cardiopulmonary remodeling in pulmonary arterial hypertension in rats
2016
Pulmonary arterial hypertension (PAH) is characterized by remodeling of the small pulmonary arteries leading to a progressive increase in pulmonary vascular resistance and right ventricular failure. Pulmonary endothelial dysfunction, inflammation and oxidative stress promote the development of pulmonary hypertension. Omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acids (DHA) have been shown to protect the cardiovascular system and reduce inflammation and oxidative stress. The present study evaluate the potential of EPA:DHA 6:1 to prevent monocrotaline-induced PAH in rats. EPA:DHA 6:1 treatment (500 mg/kg/d, p.o) prevented the MCT-induced mean pul…
Régulation des défenses antioxydantes dans la prévention du déconditionnement musculaire
2019
Musculoskeletal system plays a key role in organism’s well functioning and is responsible for a large variety of functions such as posture, locomotion, balance, and activities of daily life. The quality of the skeletal muscle is therefore capital to maintain quality of life and, in the long term, survival. Hypoactivity and aging are two situations that cause skeletal muscle deconditioning, therefore sharing common characteristics: loss of muscle strength, muscular atrophy and MyHC redistribution, as well as IMAT accumulation. To date, there is plenty of evidence supporting a causative link between oxidative stress phenomenon and muscle deconditioning. The two studies exposed in this thesis …
modifications peroxysomales associées à l'oxyapoptophagie induite par le 7-cétocholestérol et identification de lipides cytoprotecteurs
2020
Oxidative stress is often increased in several diseases such as age-related diseases (cardiovascular diseases, eye diseases (age-related macular degeneration (AMD) and cataracts), neurodegenerative diseases (Alzheimer's disease, multiple sclerosis), chronic inflammatory diseases (chronic inflammatory bowel disease (IBD)) as well as certain rare genetic diseases (Niemann Pick's disease, X-linked adrenoleukodystrophy (X-ALD)). Oxidative stress can oxidize various molecules, in particular the cholesterol present in lipid membranes, and lead to the formation of oxidized cholesterol derivatives: oxysterols. Some of them, such as 7-ketocholesterol (7KC), are toxic and may be the cause of a type o…
A potential host and virus targeting tool against COVID-19: Chemical characterization, antiviral, cytoprotective, antioxidant, respiratory smooth mus…
2023
COronaVIrus Disease 2019 (COVID-19) is a newly emerging infectious disease that spread across the world, caused by the novel coronavirus Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the advancements in science that led to the creation of the vaccine, there is still an urgent need for new antiviral drugs effective against SARS-CoV-2. This study aimed to investigate the antiviral effect of Paulownia tomentosa Steud extract against SARS-CoV-2 and to evaluate its antioxidant properties, including respiratory smooth muscle relaxant effects. Our results showed that P. tomentosa extract can inhibit viral replication by directly interacting with both the 3-chymotrypsin-like…
Postnatal programming cardiometabolic risk : effects of moderate caloric restriction in adulthood
2016
Postnatal overfeeding (PNOF) in rodents induces early programming of cardio-metabolic risk. Our aim was to determine if a moderate diet restriction could restore cardio-metabolic alterations induced by PNOF.Immediately after birth, litters of C57BL/6 mice were either maintained at 9 (normal litter, NL), or reduced to 3 (small litter, SL) to induce PNOF. At weaning, all mice received a standard diet ad libitum (AL). At 6 month of age, half of the NL and SL mice were assigned to a moderate 20% calorie restriction (CR: NLCR, SLCR) for one month, while the other mice continued to eat AL (AL: NLAL, SLAL). Glucose and insulin tolerance tests, cardiac function (echocardiography), body composition …
Senescence and longevity : from physiological mechanisms to evolutionary processes : studies in birds and mammals
2012
There is an incredible diversity of lifespan in the animal kingdom ranging from a few days for small gastrotrichs worms to several hundred of years for some bivalves or tortoises. This amazing diversity has long questioned biology researchers. The growing interest in the phenomenon of aging, mainly due to the increase in life expectancy in humans, has questioned researchers on processes that determine patterns of longevity and ageing. On the one hand, biomedical and biogerontological studies helped describe numerous cellular and physiological mechanisms related to aging. Among these mechanisms, oxidative stress has been identified as playing a major role, through life-time accumulation of d…
Role of beta3-adrenergic receptors in intestinal diseases
2022
The Inflammatory Bowel Diseases (IBD), characterized by a gastro-intestinal tract inflammation, are a global health-care problem due to their morbidity, mortality and the constant increase in their worldwide incidence. The available therapies are still not curative only providing temporary symptomatic relief and reduction in complications.Although etiology is still unclear, IBD results in an interplay of various factors among which impaired and/or inappropriate immune response toward intestinal bacteria. Increasing disease incidence link environmental triggers occurring during socioeconomic development to IBD, especially stress. In this work, we aimed to investigated the role of adrenergic …
Incidences de l’ischémie cérébrale sur la fonction et la sensibilité cardiaques à l’ischémie
2019
For years, the relationship between cardiac and neurological ischemic events has been limited to overlapping pathophysiological mechanisms and common risk factors. However, acute stroke may induce dramatic changes in cardiovascular function.The aim of this study was to evaluate how prior cerebrovascular lesions affect myocardial function and signaling in vivo and ex vivo, and how they influence cardiac vulnerability to ischemia-reperfusion injury and the expression of cardiac genes and proteins involved in cardioprotective pathways.Thus, in our work, we studied cardiac function in a rat stroke model induced by cerebral embolization.The main results show that experimental stroke 1/ impaired …
Implications du stress oxydant et du fer dans la cardiotoxicité des anthracyclines et du trastuzumab
2015
Cancer treatment has advanced considerably in recent years, allowing a reduction in mortality. Longer life expectancy of patients has helped to highlight the delayed onset of cardiovascular toxicity induced by these chemotherapies. The pathophysiological mechanisms responsible for these cardiac dysfunctions are complex, entangled and remain partially unknown. A better understanding of the phenomena involved in these cardiotoxicities is needed to prevent their occurrence. Therefore, we have developed two different experimental approaches to understand the pathophysiological mechanisms involved in the cardiac toxicity of anthracyclines and trastuzumab.A first experimental study aimed to clari…
Utilisation of natural carotenoids from Momordica cochinchinensis (gac) as health compounds : extraction and bioactvity depending on the origin and o…
2014
The aril of Momordica cochinchinensis (gac), plant from the Cucurbitaceae family, is the richest source of lycopene and β-carotene, which are a strong antioxidant and a pro-vitamin A, respectively, interesting for health-complements. First, a process of soft extraction-fractionation was developed for extracting effectively the natural carotenoids from gac without loss of their original quality. Then, the lycopene and β-carotene extracted from gac were analyzed and characterized. At least 95% of the extracts were composed of the all-trans isomer. They were not degraded during the heat-treatment mimicking formulation processing. Their thermal stereo-mutation was evaluated. Lycopene is more an…