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This study was aimed at investigating the hypocholesterolemic effects of extra virgin olive oil (EVOO) phenols and the mechanisms behind the effect. Two phenolic extracts were prepared from EVOO of different cultivars and analyzed using the International Olive Council (IOC) official method for total phenols, a recently validated hydrolytic procedure for total hydroxytyrosol and tyrosol, and 1H-NMR analysis in order to assess their secoiridoid profiles. Both of the extracts inhibited in vitro the 3-hydroxy-3-methylglutaryl co-enzyme A reductase (HMGCoAR) activity in a dose-dependent manner. After the treatment of human hepatic HepG2 cells (25 &micro, g/mL), they increased the low-density lipoprotein (LDL) receptor protein levels through the activation of the sterol regulatory element binding proteins (SREBP)-2 transcription factor, leading to a better ability of HepG2 cells to uptake extracellular LDL molecules with a final hypocholesterolemic effect. Moreover, both of the extracts regulated the intracellular HMGCoAR activity through the increase of its phosphorylation by the activation of AMP-activated protein kinase (AMPK)-pathways. Unlike pravastatin, they did not produce any unfavorable effect on proprotein convertase subtilisin/kexin 9 (PCSK9) protein level. Finally, the fact that extracts with different secoiridoid profiles induce practically the same biological effects suggests that the hydroxytyrosol and tyrosol derivatives may have similar roles in hypocholesterolemic activity.

La parola «nutraceutica» è la crasi, non solo semantica, tra i termini nutrienti e farmaceutica, e la disciplina corrispondente richiede la conoscenza di aspetti chimici e biologici, oltre a mostrare che tipo di declinazione ha impresso alla chimica degli alimenti. A partire dal 1990 infatti, anno in cui si è tenuto in Italia il primo Congresso nazionale di Chimica degli alimenti, l’attenzione in questo campo ha cominciato a orientarsi verso la presenza di contaminanti organici e inorganici nei cibi, di metaboliti secondari e di microcostituenti di interesse nutraceutico e salutistico. Da allora sono stati fatti molti passi avanti e questo settore si è rivelato strategico dal punto di vista economico, della salute della popolazione e dell’ampliamento delle conoscenze riguardanti il nostro metabolismo. Oggi abbiamo a disposizione la possibilità di svolgere indagini approfondite sugli aspetti compositivi degli alimenti e sulla loro tracciabilità, grazie a sistemi innovativi quali le tecniche multidimensionali, per esempio quelle heart-cutting e comprehensive, o le nuove tecniche di spettrometria di massa, per citarne alcune. Gli alimenti sono così descrivibili per la loro composizione, o per le loro proprietà tecnologiche, reologiche o per le caratteristiche commerciali e sensoriali, ma anche per il contributo che possono dare alla salute e al benessere, cosa che intende fare questo libro. La chimica e gli alimenti - Nutrienti e aspetti nutraceutici è un testo che unisce la descrizione della composizione chimica degli alimenti in termini di micro e macronutrienti e di metaboliti secondari, e dei loro effetti salutistici, all’aspetto legislativo, passando in rassegna le tappe più significative che ha attraversato la legislazione in materia negli ultimi anni; dà anche conto degli aspetti analitici più avanzati, oltre a non trascurare il tema della sicurezza e l’importanza della componente sensoriale degli alimenti.

The present investigation sought to evaluate cellular antioxidant activities of some green leafy vegetables: Vernonia amygdalina, Asteraceae (Va,); Manihot utilissima Pohl., Euphoriaceae (Mu);Corchorous olitorius L., Malvaceae (Co) and Occimum gratissimum L., Lamiaceae (Og) against peroxyl radical-induced oxidation in HepG2 cells and also evaluate their cytotoxic properties against drug sensitive and drug resistant Lovo and Lovo/Adr cancer cell lines respectively. HPLC/DAD/MS investigation of the ethanolic extract of the vegetal matter revealed the presence of 4, 5, 6, and 7 phenolic compounds in Mu, Co, Og and Va respectively. The cellular antioxidant activity was tested with different concentrations (0.1, 0.25, 0.5 and 1.00 mg/ml dried weight) of the extracts. At a concentration of 1.00 mg/ml, the quenching of peroxyl radical in HepG2 cells as shown by the fluorescence units revealed that Og has the best inhibition capacity, followed by Co, Va respectively and with the least inhibition capacity recorded for Mu. However, pro-oxidant activities were observed at lower concentrations of Va (0.1 mg/ml) and Mu (0.1, 0.25 and 0.5 mg/ml). Cytotoxic investigation revealed that the extracts were active against both cell lines with EC50 (µg/ml) ranging from 1.3 to 2.6 for Lovo and 1.5 to 2.7 for Lovo/Adr respectively, and that Va was the most active, while the least activity was recorded for Mu and Co for Lovo and Lovo Adr respectively. The observed cytotoxic properties and the elicited antioxidant activities would be due to the phytochemical constituents among which could be the rich content of flavonoids and cynammoyl derivatives as revealed by the chromatographic investigations.

Variation in aromatic fraction was investigated between 4 selected garlic clones from in vivo and in vitro cultures. The selected plant material included one Polesano white-type garlic clone and 3 Sulmona red-type garlic clones. The aromatic fraction was determined by means of headspace gas chromatography (HS-GC). Major compounds were diallyl disulphide and allyl methyl sulphide. The results of this preliminary work showed a large variation in several compounds respectively from in vivo and in vitro cultures: analyses of the aromatic fraction revealed differentiation between the different clones and showed three groupings, corresponding to the pooled Sulmona red-type garlic clones (Sulmona 3 and Sulmona 6) and the other individually separated clones.