Wine extracts from Sardinian grape varieties attenuate membrane oxidative damage in Caco-2 cell monolayers.

One of the most important sites of polyphenol action seems to be in the gastrointestinal system before absorption. We investigated the ability of three wine phenolic extracts, obtained from grape varieties grown in Sardinia, Cannonau (red), Vermentino and Malvasia (white), to exert an antioxidant action against tert-butyl hydroperoxide (TBH)-induced oxidative damage to Caco-2 cell monolayers as a model system of the human intestine. TBH treatment caused the disruption of epithelial integrity, measured as transepithelial electrical resistance, and markers of the peroxidation process of membrane lipids, MDA, fatty acid hydroperoxides and 7-ketocholesterol.

Antioxidant profile of strawberry tree honey and its marker homogentisic acid in several models of oxidative stress.

The antioxidant activity of several honeys was evaluated considering the different contribution of entire samples. The strawberry tree honey emerged as the richest in total phenols and the most active honey in the DPPH and FRAP tests, and could protect cholesterol against oxidative degradation (140°C). Homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA), the main phenolic compound from strawberry tree honey, showed interesting antioxidant and antiradical activities, and protective effect against thermal-cholesterol degradation, comparable to those of well known antioxidants.

Hydroxytyrosol inhibits the proliferation of human colon adenocarcinoma cells through inhibition of ERK1/2 and cyclin D1.

Extra virgin olive oil is rich in phenolic compounds which are believed to exert beneficial effects against many pathological processes, including the development of colon cancer. We show that one of the major polyphenolic constituents of extra virgin olive oil, hydroxytyrosol (HT), exerts strong antiproliferative effects against human colon adenocarcinoma cells via its ability to induce a cell cycle block in G2/M. These antiproliferative effects were preceded by a strong inhibition of extracellular signal-regulated kinase (ERK)1/2 phosphorylation and a downstream reduction of cyclin D1 expression, rather than by inhibition of p38 activity and cyclooxygenase-2 (COX-2) expression.

Flavonoid characterization and antioxidant activity of hydroalcoholic extracts from Achillea ligustica All.

Ethanolic extracts of Achillea ligustica All. (Asteraceae) flowering tops were evaluated. High-performance liquid chromatography-electrospray ionisation-mass spectrometry was used for the identification and quantification of phenolic compounds.

Lipid peroxidation in plasma of rats treated with ferric-nitrilotriacetate, in relation to kidney and liver modifications.

Intraperitoneal injection of the iron chelate ferric-nitrilotriacetate (Fe-NTA) induces in rodents renal and hepatic suffering, associated with oxidative damage. We investigated the oxidation pattern in plasma of treated rats in relation to liver and kidney, monitoring the variation of the lipid components more susceptible to oxidation, unsaturated fatty acids (UFA) and alpha-tocopherol, as biomarkers of the oxidative damage. A sublethal dose of Fe-NTA induced a strong and extremely significant decrease of UFA levels at 1 h after injection in the plasma compartment and at 3 h in the kidney, with reductions up to 40-50% of the control values, together with an increase of conjugated dienes fatty acids hydroperoxides and a consumption of alpha-tocopherol.

Antioxidant activity of supercritical extract of Melissa officinalis subsp. officinalis and Melissa officinalis subsp. inodora.

The antioxidant activity of Melissa officinalis subsp. officinalis and of Melissa officinalis subsp. inodora extracts, obtained by using carbon dioxide under supercritical conditions was investigated.