Antioxidant Effects of Sheep Whey Protein on Endothelial Cells

Excessive production of reactive oxygen species (ROS) may cause endothelial dysfunction and consequently vascular disease. In the present study, the possible protective effects of sheep whey protein (SWP) from tert-butyl hydroperoxide- (tBHP-) induced oxidative stress in endothelial cells (EA.hy926) were assessed using oxidative stress biomarkers. These oxidative stress biomarkers were glutathione (GSH) and ROS levels determined by flow cytometry. Moreover, thiobarbituric acid-reactive substances (TBARS), protein carbonyls (CARB), and oxidized glutathione (GSSG) were determined spectrophotometrically. The results showed that SWP at 0.78, 1.56, 3.12, and 6.24 mg of protein mL−1 increased GSH up to 141%, while it decreased GSSG to 46.7%, ROS to 58.5%, TBARS to 52.5%, and CARB to 49.0%. In conclusion, the present study demonstrated for the first time that SWP protected endothelial cells from oxidative stress. Thus, SWP may be used for developing food supplements or biofunctional foods to attenuate vascular disturbances associated with oxidative stress

Progress of Bromophenols in Marine Algae from 2011 to 2020:Structure, Bioactivities, and Applications

Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antiradical, antimicrobial, anticancer, antidiabetic, anti-inflammatory effects, and so on. Here, we briefly review the recent progress of these marine algae biomaterials and their derivatives from 2011 to 2020, with respect to structure, bioactivities, and their potential application as pharmaceuticals

Extracts from the Mediterranean Food Plants Carthamus lanatus, Cichorium intybus, and Cichorium spinosum Enhanced GSH Levels and Increased Nrf2 Expression in Human Endothelial Cells

The Mediterranean diet is considered to prevent several diseases. In the present study, the antioxidant properties of six extracts from Mediterranean plant foods were assessed. The extracts’ chemical composition analysis showed that the total polyphenolic content ranged from 56 to 408 GAE mg/g dw of extract. The major polyphenols identified in the extracts were quercetin,luteolin, caftaric acid, caffeoylquinic acid isomers, and cichoric acid. The extracts showed in vitro high scavenging potencyagainst ABTS•+and O2•−radicals and reducing power activity. Also, the extracts inhibited peroxyl radical-induced cleavage ofDNA plasmids. The three most potent extracts, Cichorium intybus, Carthamus lanatus, and Cichorium spinosum, inhibited OH•-induced mutations in Salmonella typhimurium TA102 cells. Moreover, C. intybus ,C. lanatus, and C. spinosum extracts increased the antioxidant molecule glutathione (GSH) by 33.4, 21.5, and 10.5% at 50μg/ml, respectively, in human endothelialEA.hy926 cells.C. intybusextract was also shown to induce in endothelial cells the transcriptional expression of Nrf2 (the majortranscription factor of antioxidant genes), as well as of antioxidant genes GCLC, GSR, NQO1, and HMOX1. In conclusion, theresults suggested that extracts from edible plants may prevent diseases associated especially with endothelium damag

Study of biological properties on extracts and plant polyphenols from greek grape varieties (vitis vinifera)

In the present study, extracts (methanolic and water) and fractions enriched in polyphenols from two Greek grape varieties, Mandilaria Santorini (red grapes) and Assyrtiko Santorini (white grapes), as well as monomeric plant polyphenols present in them were tested for their biological activity. The tested plant polyphenols were: three hydroxycinnamic acids (cafeic acid, ferulic acid and coumaric acid), two hydroxybenzoic acids (gallic acid and protocatechuic acid), four flavonoids (quercetin, rutin, (+)-catechin and (-)-epicatechin) and trans-resveratrol. The following biological properties were investigated: 1) The antioxidant activity by using the DPPH method. 2) The effect of the tested compounds on mutagenicity induced by oxidative factors. In this case, the following methods were used: i) DNA strand breakages induced by mitomycin C in plasmid DNA, ii) mutations induced by bleomycin and hydrogen peroxide in bacterial cells (Salmonella typhimurium TA102) and iii) SCEs induced by mitomycin C in cultures of human lymphocytes. 3) The effect of tested compounds on ozone-induced oxidation of SP-A protein (which is one of the major proteins of lung surfactant). 4) The effect of tested compounds on the activity of topoisomerase I enzyme. The results from the DPPH method showed the following: i) The extracts and the fractions exhibited strong antioxidant activity in low concentrations (IC50 values between 19-92 μg/ml). ii) Some of the polyphenol enriched fractions had less antioxidant activity than their corresponding extracts, and so the results suggested that the antioxidant activity of extracts is not attributed only to the polyphenols but also to other compounds or to a synergistic effect between polyphenols or between polyphenols and other compounds present in extracts. iii) The potential order of the polyphenols was: gallic acid > caffeic acid = quercetin = (-)-epicatechin > (+)-catechin > rutin > protocatechuic acid > ferulic acid > trans-resveratrol > coumaric acid. Moreover, the IC50 values some of them were in concentrations which can be achieved in the human organism through the diet. The conclusions coming from the effects of the tested compounds on the mutagenic activity induced by oxidative factors were the following: i) The extracts from both grape varieties inhibited at low concentrations the bleomycin-induced mutagenicity in bacterial cells as well as the mitomycin C-induced DNA strand breakages in plasmid DNA. Furthermore, the methanolic extracts inhibited the hydrogen peroxide-induced mutagenicity in bacterial cells. Thus, the results indicated that the inhibitory activity of grape extracts against DNA mutations induced by oxidative factors may be one of the mechanisms accounting for their chemopreventive action. ii) The antimutagenic activity of extracts could not be attributed to any of the tested polyphenols, since the concentrations of those polyphenols exerted antimutagenic activity were much lower than the concentrations of the polyphenols in the extracts. Consequently, the inhibitory activity of extracts may not be attributed to the polyphenols or there may be a synergistic activity between polyphenols or between the polyphenols and some other compounds of the extracts. iii) From the tested polyphenols, caffeic acid inhibited the bleomycin-induced mutagenicity in bacterial cells and quercetin inhibited the hydrogen peroxide-induced mutagenicity in bacterial cells as well as the mitomycin C-induced SCEs in human lymphocytes. The inhibitory activity of these polyphenols could probably be attributed not only to their strong antioxidant properties but also to their metal chelating properties. The results from the effects of the tested compounds on topoisomerase I activity showed the following: i) The extracts from both grape varieties inhibited the catalytic activity of both topoisomerase I from wheat germ and human topoisomerase I. Therefore, the inhibition of this enzyme may be one of the mechanisms accounting for the anticarcinogenic activity of grape extracts observed in other studies. ii) Some of the polyphenol enriched fractions were less potent than their corresponding extracts. Thus, the inhibitory activity of extracts against topoisomerase I may be due not only to the polyphenols but also to other compounds present in extracts. iii) From the tested polyphenols, caffeic acid, quercetin and protocatechuic acid exerted inhibition against the activity of topoisomerase I. The conclusions resulting from the effects of the tested compounds on ozone-induced oxidation of SP-A were the following: i) The flavonoids, (+)-catechin, (-)-epicatechin and rutin, inhibited in a dose-dependent manner the SP-A oxidation.lungs.Στην παρούσα μελέτη εξετάστηκε η βιολογική δράση εκχυλισμάτων (μεθανολικών και υδατικών) και πολυφαινολικών κλασμάτων από δύο ελληνικές ποικιλίες αμπέλου, Μανδηλαριά Σαντορίνης (κόκκινα σταφύλια) και Ασσύρτικο Σαντορίνης (άσπρα σταφύλια), καθώς και μονομερών φυτικών πολυφαινολών που ανιχνεύτηκαν σε αυτά. Οι φυτικές πολυφαινόλες που εξετάστηκαν ήταν: τρία υδροξυκινναμικά οξέα (καφεϊκό οξύ, φερουλικό οξύ και κουμαρικό οξύ), δύο υδροξυβενζοϊκά οξέα (γαλλικό οξύ και πρωτοκατεχοϊκό οξύ), τέσσερα φλαβονοειδή (κερκετίνη, ρουτίνη, (+)-κατεχίνη, (-)-επικατεχίνη) και η trans-ρεσβερατρόλη. Μελετήθηκαν οι εξής βιολογικές ιδιότητες: 1) H αντιοξειδωτική δράση των εξεταζόμενων ουσιών με τη μέθοδο του DPPH). 2) H επίδραση των εξεταζόμενων ουσιών σε μεταλλάξεις που προκαλούνται στο DNA από οξειδωτικούς παράγοντες. Στην περίπτωση αυτή χρησιμοποιήθηκαν οι εξής μέθοδοι: α) επαγωγή θραύσεων σε πλασμιδιακό DNA από τον οξειδωτικό παράγοντα μιτομυκίνη C, β) πρόκληση μεταλλάξεων σε βακτηριακά κύτταρα (S. typhimurium TA102) από τις μεταλλαξιγόνες ουσίες μπλεομυκίνη και Η2Ο2 και γ) αύξηση των SCEs από τη μεταλλαξιγόνο ουσία μιτομυκίνη C σε καλλιέργειες ανθρώπινων λεμφοκυττάρων. 3) H επίδραση των εξεταζόμενων ουσιών στην προκαλούμενη από το όζον οξείδωση της πρωτεΐνης SP-A του επιφανειοδραστικού παράγοντα του πνεύμονα. 4) H επίδραση των εξεταζόμενων ουσιών στη δράση του ενζύμου τοποϊσομεράση Ι. Τα αποτελέσματα από τη μέθοδο του DPPH έδειξαν τα εξής: i) Τα εκχυλίσματα και τα κλάσματα παρουσίασαν ισχυρή αντιοξειδωτική δράση σε μικρές συγκεντρώσεις (τιμές του IC50 19-92 μg/ml). ii) Oρισμένα πολυφαινολικά κλάσματα είχαν μικρότερη αντιοξειδωτική δράση από τα εκχυλίσματα από τα οποία προήλθαν, άρα η αντιοξειδωτική δράση των εκχυλισμάτων δεν οφείλεται μόνο στις πολυφαινόλες που περιέχουν τα εκχυλίσματα, αλλά και σε άλλες ουσίες ή σε μια συνεργική δράση των πολυφαινολών μεταξύ τους καθώς και με άλλες ουσίες των εκχυλισμάτων. iii) H σειρά δραστικότητάς των φυτικών πολυφαινολών ήταν γαλλικό οξύ > καφεϊκό οξύ = κερκετίνη = (-)-επικατεχίνη > (+)-κατεχίνη > ρουτίνη > πρωτοκατεχοϊκό οξύ > φερουλικό οξύ > trans-ρεσβερατρόλη > κουμαρικό οξύ και οι τιμές IC50 ορισμένων από αυτές (του καφεϊκού οξέος, του γαλλικού οξέος, της (-)-επικατεχίνης και της κερκετίνης) ήταν σε συγκεντρώσεις που μπορούν να επιτευχθούν στους οργανισμούς μέσω της δίαιτας. Τα συμπεράσματα που προέκυψαν από την επίδραση των εξεταζόμενων ουσιών στη μεταλλαξιγόνο δράση οξειδωτικών παραγόντων είναι τα εξής: i) Tα εκχυλίσματα και των δύο ποικιλιών αμπέλου ανέστειλαν σε μικρές συγκεντρώσεις τη μεταλλαξιγόνο δράση της μπλεομυκίνης στα βακτηριακά κύτταρα καθώς και τις επαγόμενες από τη μιτομυκίνη C θραύσεις του πλασμιδιακού DNA, ενώ επίσης τα μεθανολικά εκχυλίσματα ανέστειλαν την προκαλούμενη από το Η2Ο2 μεταλλαξιγένεση στα βακτηριακά κύτταρα. Συνεπώς, η ανασταλτική δράση των εκχυλισμάτων αμπέλου έναντι των βλαβών που προκαλούνται στο DNA από οξειδωτικούς παράγοντες ίσως να είναι ένας από τους μηχανισμούς στους οποίους οφείλεται η χημειοπροστατευτική τους δράση. ii) H αντιμεταλλαξιγόνος δράση των εκχυλισμάτων δεν θα μπορούσε να αποδοθεί σε καμία από τις εξεταζόμενες πολυφαινόλες, γιατί οι συγκεντρώσεις των πολυφαινολών εκείνων που έδειξαν ανασταλτική δράση ήταν πολύ μικρότερες από τις συγκεντρώσεις των πολυφαινολών στα εκχυλίσματα. Άρα η ανασταλτική δράση των εκχυλισμάτων, ή δεν οφείλεται στις πολυφαινόλες ή υπάρχει μία συνεργική δράση μεταξύ των πολυφαινολών ή μεταξύ των πολυφαινολών και άλλων ουσιών των εκχυλισμάτων. iii) Από τις πολυφαινόλες, ανασταλτική δράση παρουσίασαν το καφεϊκό οξύ έναντι της επαγόμενης από μπλεομυκίνη μεταλλαξιγένεσης στα βακτηριακά κύτταρα και η κερκετίνη έναντι της επαγόμενης από Η2Ο2 μεταλλαξιγένεσης στα βακτηριακά κύτταρα αλλά και έναντι της μιτομυκίνης C στη μέθοδο με τις SCEs. H ανασταλτική δράση αυτών των πολυφαινολών οφείλεται πιθανώς στο ότι διαθέτουν ισχυρή αντιοξειδωτική δράση αλλά παράλληλα και ισχυρές χηλικές ιδιότητες. Η μελέτη της επίδρασης των εξεταζόμενων ουσιών στη δράση της τοποϊσομεράσης Ι έδειξε τα εξής: i) Τα εκχυλίσματα και από τις δύο ποικιλίες ανέστειλαν τη δράση της ανθρώπινης τοποϊσομεράσης Ι καθώς και αυτής από σπέρμα σιταριού, άρα η αναστολή αυτού του ενζύμου είναι ίσως ένας από τους μηχανισμούς στους οποίους οφείλεται η αντικαρκινική δράση εκχυλισμάτων από σταφύλια που έχει παρατηρηθεί σε άλλες μελέτες

Development and Validation of a Kit to Measure Drink Antioxidant Capacity Using a Novel Colorimeter

Measuring the antioxidant capacity of foods is essential, as a means of quality control to ensure that the final product reaching the consumer will be of high standards. Despite the already existing assays with which the antioxidant activity is estimated, new, faster and low cost methods are always sought. Therefore, we have developed a novel colorimeter and combined it with a slightly modified DPPH assay, thus creating a kit that can assess the antioxidant capacity of liquids (e.g., different types of coffee, beer, wine, juices) in a quite fast and low cost manner. The accuracy of the colorimeter was ensured by comparing it to a fully validated Hitachi U-1900 spectrophotometer, and a coefficient was calculated to eliminate the observed differences. In addition, a new, user friendly software was developed, in order to render the procedure as easy as possible, while allowing a central monitoring of the obtained results. Overall, a novel kit was developed, with which the antioxidant activity of liquids can be measured, firstly to ensure their quality and secondly to assess the amount of antioxidants consumed with the respective food

Study of Stability, Cytotoxic and Antimicrobial Activity of Chios Mastic Gum Fractions (Neutral, Acidic) after Encapsulation in Liposomes

Mastic gum is a resinous sap produced by Pistacia lentiscus growing in the island of Chios (Greece) and has been recognized since Antiquity for its distinctive aroma as well as medical properties (antimicrobial, antioxidant, anti-inflammatory ones). The oral absorption of Chios Mastic gum (an insoluble polymer of poly-β-myrcene is among the most abundant contents) is poor due to its low water-solubility. We report in this study, two different Chios mastic gum extracts, the acidic mastic gum extract—AMGE—and the neutral one—NMGE, both prepared after removal of the contained polymer in order to ameliorate solubility and enhance in vivo activity. Liposomes are presented as a promising delivery system due to their physicochemical and biophysical properties to increase stability and absorption efficiency of the mastic gum extracts within the gastrointestinal (GI) tract. The aim of this study was to evaluate the stability in GI simulated conditions together with cytotoxic and antimicrobial activity of the two extracts (AMGE and NMGE) after encapsulation in a well characterized liposome formulation. Liposomes-AMGE complex showed an improved stability behavior in GI simulated conditions. Both assayed extracts showed significant dose dependent inhibition against the growth of liver cancer HepG2 cells and an interesting antimicrobial activity against several microorganisms. Conclusively, encapsulation could be evaluated as a beneficial procedure for further applications of mastic resin

Marine Bromophenol Bis(2,3,6-Tribromo-4,5-Dihydroxybenzyl)ether Inhibits Angiogenesis in Human Umbilical Vein Endothelial Cells and Reduces Vasculogenic Mimicry in Human Lung Cancer A549 Cells

Angiogenesis, including the growth of new capillary blood vessels from existing ones and the malignant tumors cells formed vasculogenic mimicry, is quite important for the tumor metastasis. Anti-angiogenesis is one of the significant therapies in tumor treatment, while the clinical angiogenesis inhibitors usually exhibit endothelial cells dysfunction and drug resistance. Bis(2,3,6-tribromo-4,5-dihydroxybenzyl)ether (BTDE), a marine algae-derived bromophenol compound, has shown various biological activities, however, its anti-angiogenesis function remains unknown. The present study illustrated that BTDE had anti-angiogenesis effect in vitro through inhibiting human umbilical vein endothelial cells migration, invasion, tube formation, and the activity of matrix metalloproteinases 9 (MMP9), and in vivo BTDE also blocked intersegmental vessel formation in zebrafish embryos. Moreover, BTDE inhibited the migration, invasion, and vasculogenic mimicry formation of lung cancer cell A549. All these results indicated that BTDE could be used as a potential candidate in anti-angiogenesis for the treatment of cancer

Bromophenol Bis (2,3,6-Tribromo-4,5-dihydroxybenzyl) Ether Protects HaCaT Skin Cells from Oxidative Damage via Nrf2-Mediated Pathways

Excessive reactive oxygen species (ROS) promotes the oxidative stress of keratinocytes, eventually causing cell damage. The natural bromophenol bis (2,3,6-tribromo-4,5-dihydroxybenzyl) ether (BTDE) from marine red algae has been reported to have a varied bioactivity; however, its antioxidant effect has yet to be investigated systemically. Our present work aimed to explore the antioxidant effect of BTDE both on the molecular and cellular models and also to illustrate the antioxidant mechanisms. Our results showed that BTDE could effectively scavenge ABTS free radicals and protect HaCaT cells from damage induced by H2O2. Mechanism studies in HaCaT cells demonstrated that BTDE attenuated hydrogen peroxide (H2O2)-induced ROS production, reduced the malondialdehyde (MDA) level, decreased the oxidized glutathione (GSSG)/glutathione (GSH) ratio, and increased the antioxidant enzyme superoxide dismutase (SOD). Moreover, BTDE could inhibit the expression of Kelch-like epichlorohydrin-associated protein 1 (Keap1) and increase the expression of both nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins TrXR1, HO-1, and NQO1. BTDE also activated the upstream signaling pathway of Nrf2 such as AKT pathway, while not activating the ERK or AMPKα pathways. In general, BTDE is a promising antioxidant to protect HaCaT cells against oxidative damage via Nrf2-mediated pathways