Effets des acides gras oméga-3 sur la cardioprotection (étude des acides gras oméga-3 chez le rat et chez des patients porteurs d'un défibrillateur automatique implantable)

Bien que le régime méditerranéen (MED) soit considéré comme le meilleur régime alimentaire pour prévenir les maladies cardiaques, on ignore toujours si l'adoption de MED résulte en une amélioration de la résistance du myocarde à l'ischémie et la reperfusion et en une prévention des arythmies ventriculaires. En conséquence, nous avons mené deux études: (1) vérifier si un profile lipidique de type MED; faible en gras saturés et en acides gras oméga-6 (?6) et riche en acides gras oméga-3 (?3) d'origines végétale et marine; peut réduire la taille d'infarctus et une meilleure récupération de la fonction ventriculaire gauche (FVG) dans un modèle de rat. Les rats MED ont été comparés avec des rats recevant des régimes riches en acides gras saturés ou en acides gras ?6. Les résultats montrent une grande accumulation des ?3 et une diminution de l'acide arachidonique dans le plasma, les membranes des cellules cardiaques et dans les mitochondries. Pareillement, les rats MED avaient une taille infarctus plus réduite par rapport aux deux autres groupes, tandis que FVG récupération n'était pas différente dans les trois groupes. La deuxième étude épidémiologique a été menée au Centre Hospitalier Universitaire de Grenoble pour déterminer une éventuelle corrélation entre les oméga-3 et la survenue de complications rythmiques. Deux cent trente huit patients porteurs de défibrillateurs automatiques implantables (DEF) ont été inclus. La composition en acides gras des globules rouges a été analysé et l'index oméga-3 a été calculée à partir de l'acide eicosapentaénoïque et acide docosahexaénoïque. Aucune différence significative entre les acides gras oméga-3 (ALA, EPA et DHA) ou l'index oméga-3 et la survenue d'événements n'a été observée entre quartiles. Néanmoins, l'index oméga-3 chez ces patients était déjà à des niveaux qui ont été démontrés avoir un pouvoir cardioprotecteur (6,6 :t 0,55% à 11,1 % :t 0,81).Although the Mediterranean diet (MED) is considered the optimal diet to prevent coronary heart disease (CHD), it is still unknown whether adoption of MED may result in improved myocardial resistance to ischemia-reperfusion injury and may potentially prevent ventricular arrhythmias. Accordingly, the first experimental study was carried out to investigate whether a diet low in saturated fats and omega-6 fatty acids (?6) but rich in plant and marine omega-3 fatty acids (?3), a typical MED fatty acid profile, may result in smaller infarct size and better left ventricular function (L VF) recovery in a rat model of regional ischemia reperfusion. Results demonstrate a great accumulation of ?3 and a parallel decrease of arachidonic acid in plasma, cell membranes and cardiac mitochondria. Also, the MED rats developed smaller infarct size compared with the control groups (p<O.OI) while LVF recovery was not different in the three groups. The second epidemiologic study was carried out to determine whether ?3 have beneficial antiarrhythmic effects in patients at high risk for fatal ventricular arrhythmias. Two hundred thirty eight patients with implantable cardioverter defibrillators (ICDs) were included at Grenoble University Hospital. The primary end point was time to first ICD event for ventricular tachycardia or fibrillation (VT or VF) or death from cardiac cause. Red blood cells fatty acids was analyzed and the Omega-3 Index was calculated from eicosapentaenoic acid and docosahexaenoic acid. Results did not show significant differences neither in individual omega-3 fatty acids (ALA, EP A and DRA) nor in omega-3 index between quartiles. However, it cornes into view that the RBC omega-3 index in these patients (6.6:t0.55% to 11.1 %:t0.8l) was already at levels that have been previously reported to be cardioprotective.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Urtica dioica L. leaf chemical composition: A never-ending disclosure by means of HR-MS/MS techniques

The metabolite profiling of plant extracts always represents an exciting challenge, as the chemical diversity of natural products is still far beyond the researchers’ imagination, even focusing on a plant that is thought to have already been broadly investigated. Herein UHPLC-HRMS/MS techniques were applied to an alcoholic crude extract from nettle leaves and proved to be a precious tool for the disclosure of secondary metabolites never found before. Hydroxycinnamic acid derivatives were the most representative constituents, with a 2-caffeoilisocitric acid cyclodimer described for the first time, besides four C-glycosylated flavones, bearing a 3-hydroxy-3-methylglutaryl function. This deep investigation paves the way for the isolation and full characterization of these molecules by means of spectroscopic techniques. Moreover, based on preliminary cytotoxicity evaluation, further research on the use of this nettle extract as a valuable nutraceutical product is encouraged

Protective effect of dietary n-3 polyunsaturated fatty acids on myocardial resistance to ischemia-reperfusion injury in rats.

International audienceDietary n-3 polyunsaturated fatty acids (PUFA) reduce coronary heart disease (CHD) complications, such as chronic arrhythmia and sudden cardiac death. Improved myocardial resistance to ischemia-reperfusion injury results in smaller myocardial infarction, which is a major factor in the occurrence of CHD complications. We hypothesized that a specific dietary fatty acid profile (low in saturated and n-6 PUFA but high in plant and marine n-3 PUFA) may improve myocardial resistance to ischemia-reperfusion injury and reduce infarct size. To test this assumption, we used a well-defined rat model of myocardial infarction. Based on our results, in comparison to a diet that is high in either saturated or n-6 PUFA but poor in plant and marine n-3 PUFA, a diet that is low in saturated fats and n-6 PUFA but rich in plant and marine n-3 PUFA results in smaller myocardial infarct size (P < .01). The effects of the 3 diets were also examined by analyzing the fatty acid composition of plasma, erythrocyte cell membranes, and the phospholipids of myocardial mitochondria. The results show a great accumulation of n-3 PUFA and a parallel decrease in arachidonic acid, the main n-6 PUFA, in plasma, cell membranes, and cardiac mitochondria (P < .0001). We conclude that improved myocardial resistance to ischemia-reperfusion may be one of the critical factors explaining the protective effects of dietary n-3 PUFA against CHD complications in humans. In addition to increasing n-3 PUFA intake, an optimal dietary pattern aimed at reducing cardiovascular mortality should include a reduction of the intake of both saturated and n-6 PUFA

Phenolic content and antioxidant activities of Vitis vinifera L. leaf extracts obtained by conventional solvent and microwave-assisted extractions

Grapevine leaves are used in the cuisines in the countries surrounding the Mediterranean and in folk medicine. They contain a huge amount of phenolic constituents. To optimize the extraction of bioactive compounds present in grapevine leaves, two methods of extraction were compared: conventional solvent extraction (CSE) and microwave-assisted extraction (MAE). The optimal extraction conditions in term of total phenolic content (TPC) were determined using a Box–Behnken design (BBD) from leaves of Vitis vinifera L. cv. Le tizourine Bou Afraraet. Optimal extraction conditions for CSE was 29% concentration of ethanol (v/v), 30.96 min extraction time, and 72:1 liquid-to-solid ratio (mL:g), at 37.5 °C. For MAE it was 34% concentration of ethanol(v/v), 474 W microwave power, 47 s irradiation time and 40:1 liquid-to-solid ratio (mL:g). Both extracts obtained by optimized MAE and CSE processes were compared in terms of total flavonoid content (TFC) and antioxidant activities (DPPH, ORAC, PFRAP and ICA). The MAE extract exhibited highest phenolic content and antioxidant activities. Moreover, phenolic compounds from leaves of Vitis vinifera L. cv. Ahmar-Bou-Amar were extracted following MAE optimal conditions and compared to Le tizourine Bou Afraraet extract. In addition to TPC and antioxidant activities, phenolic constituents were determined using HPLC–DAD-IT-MS and UPLC-QqQ-MS/MS. A total of sixteen phenolic compounds were identified and quantified including two phenolic acids, seven flavonols, three flavanols and four stilbenes. The obtained data revealed that the leaves of two native Algerian grapevines are rich in bioactive constituents, and can constitute by-products with added-value for food supplements

HPLC-UV/DAD and ESI-MSn analysis of flavonoids and antioxidant activity of an Algerian medicinal plant: Paronychia argentea Lam

This study was carried out in order to evaluate the effect of the preparation method (decoction and infusion) on the flavonoid profile, phenolic content and antioxidant activity of the aerial parts of Paronychia argentea Lam. (Caryophyllaceae), also known as Arabic tea. Eleven flavonoids were characterized by using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MSn) and quantified by HPLC-UV/DAD; six of them, including isorhamnetin-3-O-dihexoside, quercetin-3-O-glucoside, quercetin methylether-O-hexoside, quercetin, jaceosidin and isorhamnetin, were described in this plant for the first time in this study. The plant ethanol extract (used as a control) showed the highest content of phenolic compounds, followed by the decoction and infusion. The antioxidant activity of the decoction (reducing power, scavenging capacity on DPPH radical and inhibition of lipid peroxidation) was found to be higher than that of the infusion. The decoction obtained from the aerial part of P. argentea can be considered as a protective beverage against oxidative stress

HPLC-UV/DAD and ESI-MSn analysis of flavonoids and antioxidant activity of an Algerian medicinal plant: Paronychia argentea Lam

Paronychia argentea Lam., belonging to the Caryophyllaceae family, is a perennial plant widely distributed in Algeria. Even though this plant is used in the Algerian popular medicine, its phytochemical characterization is incomplete. In this study, the flavonoid profile and the in vitro antioxidant activity of the ethanolic extract, decoction and infusion of P. argentea aerial parts are reported. Flavonoids were analyzed by means of high-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry. Eleven compounds were identified and six of them, including isorhamnetin-3-O-dihexoside, quercetin-3-O-glucoside, quercetinmethylether-O-hexoside, quercetin, jaceosidin and isorhamnetin, were described in this plant for the first time. The ethanol extract showed the highest flavonoid content, followed by the decoction and the infusion (25.4 +/- 0.8 mg/g of DM, 8.4 +/- 0.5 mg/g of DM, 0.2 mg/g of DM, respectively), while the best antioxidant activity was shown by the decoction (RC0.5 =178 mu g/mL for reducing power, 72.4% of inhibition of lipid peroxidation, IC50 =27.38 mu g/mL for DPPH center dot radical scavenging activity and 59.7% of inhibition of NO center dot radical). These results showed that P. argentea decoction could be considered as a valuable source of flavonoids and antioxidants that might contribute to the valorization of the phytotherapeutic potential of this plant

J. food meas. charact

The recovery of food waste is a stimulating opportunity for and competitive development of agroindustries. In this context, the objective of this study was to report the antioxidant potential and phenolic compounds content of olive stones (OS) of six Algerian cultivars. Two extraction methods were used: microwave assisted extraction (MAE) and conventional solvent extraction (CSE) in order to improve the recovery of total phenolic content (TPC) and the maximization of the two extraction processes by the Box-Behnken design (BBD) from olive stone of Olea Europaea L. cv Ayemele. The optimal processing parameters obtained were (i) for MAE: 22% (v/v) ethanol, 40 s, 500 W, and ratio 65:1 (mL/g) and (ii) for CSE: 33% (v/v) ethanol, 24 min, 71°C, and ratio 60:1 (mL/g). Phenolic compounds were then extracted from olive stones of six Algerian cultivars with MAE best extraction conditions, as it was the best strategy in term of TPC recovery. The phenolic content was different according to the olive variety. The stones of Chemlale were the richest in TPC (7.23 mg GAE/g) followed by Azeboudj (6.33 mg GAE/g), Atefah (6.04 mg GAE/g), Agraraz (5.63 mg GAE/g), Azeradj (5.35 mg GAE/g) and Ayemel (5.14 mg GAE/g). A similar profile was observed with total flavonoids content and antioxidant activities. The anti-inflammatory effects of the optimized extracts by MAE were assessed regarding their ability to prevent lipopolysaccharide-induced of reactive oxygen species and nitric oxide production in a macrophage cell line (RAW 264.7). Olive stones that are issued from the production of olive oil, and table olives can therefore be considered as renewable by-products thanks to their compounds with high added value. These bioactive compounds can target the food natural additives markets, pharmaceutical and cosmetic industries, all of which are currently very receptive such natural products

A nutraceutical extract from Inula viscosa leaves: UHPLC-HR-MS/MS based polyphenol profile, and antioxidant and cytotoxic activities

Nowadays, advanced extraction techniques and highly sensitive metabolic profiling methods are effectively employed to get new information on plant chemical constituents. Among them wild medicinal plants or their parts, with large and ancient use in folk medicine, are investigated for their potential functional use and cultivation. In this context, Inula viscosa leaves engaged our attention. A simple experimental design, based on Soxhlet extraction and chromatographic fractionation, allowed us to obtain the investigated polyphenol fraction (IvE). UHPLC-HRMS analyses revealed shikimoyl depsides of caffeic acid and unusual dihydrobenzofuran lignans as main secondary metabolites. These compounds, together with cinchonain-type phenols, and hydroxycinnamoyl flavonol glycosides, are reported for the first time in inula. Overall, forty-three secondary metabolites were identified. The extract exerted a remarkable antiradical activity towards DPPH• and ABTS+•. Furthermore, it was able to inhibit cell viability and mitochondrial redox activity of neuroblastoma, hepatoblastoma and colon carcinoma cells, whereas it did not affect cell density of HaCaT cells immortalized human keratinocytes. As detected by the oxidant-sensing probe 2′,7′-dichlorodihydrofluorescein diacetate, the inhibitory responses seemed to be related to IvE-induced increase of intracellular reactive oxygen species (ROS). The obtained results highlighted that inula leaves, nowadays even undervalued and unexplored, could be considered a renewable source of nutraceutical compounds