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The aim of this work is the evaluation of a green extraction technology to exploit winery waste byproducts. Specifically, a solid⁻liquid extraction technology (Naviglio Extractor ® ) was used to obtain polyphenolic antioxidants from the Cagnulari grape marc. The extract was then chemically characterized by spectrophotometric analysis, high-performance liquid chromatography, and mass spectrometry, revealing a total polyphenol content of 4.00 g/L ± 0.05, and the presence of anthocyanins, one of the most representative groups among the total polyphenols in grapes. To investigate potential biological activities of the extract, its ability to counteract hydrogen peroxide-induced oxidative stress and cell death was assessed in primary human endothelial cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, used to assess potential extract cytotoxicity, failed to show any deleterious effect on cultured cells. Fluorescence measurements, attained with the intracellular reactive oxygen species (ROS) probe 2',7'-dichlorodihydrofluorescein diacetate (H₂DCF-DA), revealed a strong antioxidant potential of the marc extract on the used cells, as indicated by the inhibition of the hydrogen peroxide-induced ROS generation and the counteraction of the oxidative-induced cell death. Our results indicate the Naviglio extraction, as a green technology process, can be used to exploit wine waste to obtain antioxidants which can be used to produce enriched foods and nutraceuticals high in antioxidants.

The aim of this work is the evaluation of a green extraction technology to exploit winery waste byproducts. Specifically, a solid-liquid extraction technology (Naviglio Extractor®) was used to obtain polyphenolic antioxidants from the Cagnulari grape marc. The extract was then chemically characterized by spectrophotometric analysis, high-performance liquid chromatography, and mass spectrometry, revealing a total polyphenol content of 4.00 g/L ± 0.05, and the presence of anthocyanins, one of the most representative groups among the total polyphenols in grapes. To investigate potential biological activities of the extract, its ability to counteract hydrogen peroxide-induced oxidative stress and cell death was assessed in primary human endothelial cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, used to assess potential extract cytotoxicity, failed to show any deleterious effect on cultured cells. Fluorescence measurements, attained with the intracellular reactive oxygen species (ROS) probe 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA), revealed a strong antioxidant potential of the marc extract on the used cells, as indicated by the inhibition of the hydrogen peroxide-induced ROS generation and the counteraction of the oxidative-induced cell death. Our results indicate the Naviglio extraction, as a green technology process, can be used to exploit wine waste to obtain antioxidants which can be used to produce enriched foods and nutraceuticals high in antioxidants. [ABSTRACT FROM AUTHOR]

Purpose: The dietary flavonoids epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) have been shown to interact with circulating albumin for transport in blood to different body tissues. This interaction may modulate their bioavailability and effectiveness. Methods: Using affinity capillary electrophoresis to assess binding constants ( K ), we investigated whether posttranslational modification of human serum albumin (HSA) through N- and S-homocysteinylation, commonly observed in hyperhomocysteinemia, may modify its interaction with catechins. Results: S-Hcy HSA had lower K values toward EC (14 %), EGC (18 %), ECG (24 %) and EGCG (30 %). Similarly, N-Hcy HSA had lower K values toward EC (17 %), EGC (22 %), ECG (23 %) and EGCG (32 %). No differences were observed in the affinity between catechins, albumin and mercaptalbumin. Conclusion: Therefore, HSA posttranslational modifications typical of hyperhomocysteinemia reduce its affinity to catechins, potentially affecting their pharmacokinetics and availability at the active sites. [ABSTRACT FROM AUTHOR]

Green tea consumption has been shown to possess cancer chemopreventive activity. Polyphenol E (PE) is a widely used standardized green tea extract formulation. This study was designed to investigate the impact of PE on prostate cancer cells (PC3), analyze the potential signals involved and elucidate whether anti- or pro-oxidant effects may be implicated. Treatment of PC3 cells with 30 and 100 μg/ml PE significantly decreased cell viability and proliferation. At the tested concentrations, PE did not exert any antioxidant activity, eliciting instead a pro-oxidant effect at concentrations 30 and 100 μg/ml, which was consistent with the observed PE cytotoxicity. PE-induced cell death was associated with mitochondrial dysfunction and downregulation of Akt activation, thus suggesting their implication in the PE-elicited cell dysfunction. Cell exposure to the ROS scavenger N-Acetyl Cysteine prevented PE-induced ROS increase, pAkt impairment, and cell death, clearly indicating the causative role of ROS in the observed phenomena. Failure of PE to induce PC3 damage in cells overexpressing Akt further confirms its implication in the PE-elicited cell death. Our findings showed an association between the antiproliferative and the pro-oxidant effect elicited by PE on PC3 cells and delineates a molecular signaling pattern potentially implicated in the toxicity of PE towards prostate cancer cells. [ABSTRACT FROM AUTHOR]