1,721,021 research outputs found
Extra virgin olive oil phenolic extracts counteract the pro-oxidant and pro-infl ammatory effect of dietary cholesterol oxidation products in human intestinal cells
No full textPhysiologically relevant olive oil phenolics are neuroprotective in SH-S5Y5 cells through modulation of intracellular signaling pathways
No full textComparative antioxidant activity and 1H NMR profiling of Mediterranean fruit products
No full textIn this study the antioxidant activity of methanol extracts obtained from Mediterranean fruit products (prickly pear fruit jam and cream, myrtle berries jam, orange and mandarin-orange marmalades) was evaluated and compared in several in vitro models of oxidative stress. The compositional profile of methanol extracts (carbohydrates, organic acids, amino acids, and main phenolic compounds) was characterized by 1H NMR spectroscopy and the total phenol content was estimated by the Folin-Ciocalteu procedure. All extracts showed protective effect against thermal-cholesterol degradation, strictly correlated to total phenols. Extracts from prickly pear cream and myrtle berries jam preserved liposomes from Cu2+-induced oxidation, inhibiting the reduction of polyunsaturated fatty acids and the increase of malondialdehyde. Extracts from prickly pear cream and citrus marmalades significantly reduced the reactive oxygen species generation induced by tert-butylhydroperoxide in Caco-2 cell culture. The results of this work qualify all tested Mediterranean fruit preserves as a good source of biologically active components with considerable antioxidant potential
Studio comparativo dell’attività antiossidante di molecole di origine naturale
No full textLa scoperta di nuovi antiossidanti di origine naturale ha una notevole rilevanza farmaceutica e nutrizionale. L’attuale tendenza è quella di sostituire gli antiossidanti di sintesi per la stabilizzazione di prodotti alimentari, cosmetici e farmaceutici con composti di origine naturale. In questo lavoro è stata effettuata una comparazione dell’attività di protezione nei confronti della perossidazione lipidica di una serie di molecole fenoliche di origine naturale. E' stata valutata l'attività antiossidante di due capsinoidi naturali, il capsiato e il diidrocapsiato, presenti nei frutti di una cultivar non piccante di Capsicum annuum L. (CH-19 Sweet), di due acilfloroglucinoli oligomerici, il semimirtocummulone ed il mirtocummulone A, presenti nelle foglie del mirto (Myrtus communis), piante molto utilizzate nella dieta mediterranea. L'abilità dei vari composti fenolici di inibire la perossidazione lipidica è stata studiata in vitro durante l’autossidazione e l’ossidazione mediata dal ferro e dall'EDTA dell’acido linoleico a 37°C in assenza di solvente. L'andamento del processo ossidativo è stato seguito monitorando il consumo dell'acido grasso e la formazione dei suoi principali prodotti di ossidazione, gli idroperossidi isomeri “cis,trans” e “trans,trans”. L’attività di queste molecole è stata comparata a quella di composti naturali come l'-tocoferolo, i flavonoidi apigenina e luteolina e i composti cumarinici dafnetina e dafnoretina, precedentemente testati negli stessi sistemi sperimentali. L’attività delle molecole naturali è stata inoltre confrontata con quella l’antiossidante sintetico BHT, e per i capsiati con l’analogo sintetico vanillil nonanoato e i suoi dimeri.
Durante l’autossidazione dell’acido linoleico il capsiato ha esercitato un'ottima attività antiossidante, comparabile a quella della luteolina, dei dimeri del vanillil nonanoato e dell'-tocoferolo, seguito dal semimirtocummulone e dal diidrocapsiato, con attività paragonabile alla dafnetina, e al mirtocummulone. Durante l'ossidazione catalizzata dal ferro, i composti naturali hanno protetto l'acido linoleico dall'attacco dei radicali liberi secondo la sequenza: capsiato e dafnetina > diidrocapsiato > luteolina > semimirtocummulone > -tocoferolo > mirtocummulone. Lo misura dello spostamento della produzione degli idroperossidi verso gli isomeri cis-trans, ha permesso di evidenziare l’ attività di donazione di atomi di idrogeno dal gruppo fenolico. Il capsiato e il diidrocapsiato hanno mostrato una notevole efficacia come antiossidanti chain-braking nell'attività di scavenger dei radicali LOO•, agendo come donatori di atomi di idrogeno, e di protezione dal danno ossidativo mediato dal ferro. Il semimirtocummulone ha esercitato una significativa ed elevata attività antiossidante durante l’autossidazione dell’acido linoleico, dove anche il mirtocummulone A ha mostrato un’azione significativa, e l’ossidazione mediata dal ferro. Entrambi i composti si sono dimostrati attivi come antiossidanti chain-breaking, agendo come scavenger dei radicali LOO•, mediante donazione di atomi di idrogeno dai tre gruppi –OH dell’anello aromatico
Comparazione del profilo composizionale di caciotte di latte ovino ottenute con differenti colture probiotiche
No full textProtective effect and relation structure-activity of nonivamide and iododerivatives in several models of lipid oxidation
No full textAbstract
The introduction of an iodine atom on the vanillyl moiety of nonivamide causes a switch in the vanilloid activity (TRPV1 antagonism versus TRPV1 desensitization) and nullifies the aversive properties of capsaicinoids. In the present study we investigated the effect of iodination in the vanillyl moiety on the antioxidant activity of capsaicinoids. To this aim, we have compared the protective effects of nonivamide and three iododerivatives, 2-iodononivamide (2IN), 5-iodononivamide (5IN), and 6-iodononivamide (6IN) in a series of in vitro models of lipid oxidation, namely the autoxidation and the FeCl(3)-mediated oxidation of linoleic acid at 37 degrees C and the thermal (140 degrees C), solvent-free oxidation of cholesterol. All tested compounds could protect linoleic acid and cholesterol against oxidative degradation, the order of potency being: nonivamide>5IN>6IN approximately 2IN. Our results show that, in general, the introduction of an iodine atom on the vanillyl moiety of nonivamide causes a decrease in the antioxidant activity, and this effect is sensitive to the position of iodine on the aromatic ring, with 5IN substantially retaining the efficacy of nonivamide to protect linoleic and cholesterol against free radical attack. Moreover, the pre-treatment with 5IN, at noncytotoxic concentrations, significantly preserved LDL from Cu(2+)-induced oxidative damage at 37 degrees C for 2h, inhibiting the reduction of polyunsaturated fatty acids and cholesterol and the increase of their oxidative products. The results of the present work suggest that 5IN exerts useful antioxidant properties in different in vitro systems of lipid peroxidation. This, coupled to its lacks of pungency and TRPV1 inhibiting properties, qualifies this phenolic compound as an attractive candidate for further investigations in vivo
H2O2 oxidative activity: modulatory effect of hydroxytyrosol
No full textHydroxytyrosol (HT) is the major o-diphenol present in extra-virgin
olive oil, either in free or esterified form, once absorbed, is present in
high amount in the kidney, where it may exert a proctetive action. In this
study we monitored the ability of HT to protect renal cells (LLC-PK1)
against oxidative damage induced by H2O2. The peroxidation of lipid represents
a primary consequences of cellular oxidative stress, leading to
biophysical changes that disrupt membrane and organelle function; moreover
oxidative stress is a process that may stimulate cellular signalling
pathways, usually associated with the promotion of cellular death. HT
exerted a significant antioxidant action, inhibiting the production of
fatty acids hydroperoxides and 7-ketocholesterol induced by H2O2 treatment
and thus preserving the membrane lipids. It has been shown that
oxidative stress in LLC-PK1 cells is related also to the changes in the
phosphorylation state of pro-death signalling pathways ERK1/2 and the
pro-survival signalling Akt/PKB. Pretreatment with HT is able to modulate
H2O2-induced changes in the phosphorylation state of ERK1/2
and Akt/PKB. We suggest that one potential protective mechanism of
olive oil polyphenols in kidney cells may be attributed to interactions
with intracellular signalling pathways activated in response to oxidative
stress
Bottarga di muggine come fonte di acidi grassi n-3: stabilità ossidativa e modulazione del profilo lipidico in cellule epiteliali intestinali Caco-2
No full textThe importance of n-3 polyunsaturated fatty acids (n-3 PUFA) intake has long been recognized in human nutrition, lowering the incidence of atherosclerosis, coronary heart disease, inflammatory disease and cancer. Although health benefits, n-3 PUFA are subject to rapid and/or extensive oxidation during processing and storage, resulting in potential alteration in nutritional composition and quality of food. Bottarga, the salted and semidried mullet (Mugil cephalus) ovary product, is proposed as important source of n-3 PUFA, having high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In this work we investigated the extent of lipid oxidation of grated bottarga samples during 7 months at different storage conditions (-20°C, 2°C, room temperature under light/dark exposure). Cell viability, lipid composition and lipid peroxidation were measured in intestinal epithelial Caco-2 cell monolayers after 6-48 h incubation with lipid and hydrophilic extracts obtained from bottarga samples at different storage conditions. Storage of bottarga did not affect the n-3 PUFA level, but significant differences were observed in hydroperoxide and malondialdeyde levels of samples from different storage conditions. Bottarga extracts did not show a toxic effect on cell viability. Epithelial cells incubated with bottarga oil had significant changes in fatty acid composition with an accumulation of EPA, DHA, and 22: 5, however, did not accumulate more cholesterol than control cells
Valutazione della perossidazione lipidica nel plasma di ratti trattati con nitrilotriacetate ferrico (FeNTA).
No full text
- …
