Characterization of bioactive compounds and antioxidant activity of fruit beers.

Total polyphenols and flavonoids content, phenolics profile by HPLC, and antioxidant activity of ten fruit beer produced adding fruits during the fermentation process were analyzed. The fruits were: cherry, raspberry, peach, apricot, grape, plum, orange and apple. Antioxidant activity, total polyphenols and flavonoids content were considerably higher in most of the fruit beers in respect to conventional, no-fruit beers. Cherries beers exhibit the highest values, followed by grape, plum and orange beers. An enrichment was observed in catechin and quercetin content in all fruit beers examined. Myricetin and resveratrol were also detected in most of the fruit beers. Among phenolic acids, an enrichment in chlorogenic, neochlorogenic, p-coumaric and caffeic acids was measured in most of the fruit beers in respect to conventional beers. Our findings show that fruits addition during the fermentation process considerably increased the antioxidant activity of beer and qualitatively and quantitatively improved its phenolics profile.

Redox Role of Lactobacillus casei Shirota Against the Cellular Damage Induced by 2,2'-Azobis (2-Amidinopropane) Dihydrochloride-Induced Oxidative and Inflammatory Stress in Enterocytes-Like Epithelial Cells.

In western societies where most of the day is spent in the postprandial state, the existence of oxidative and inflammatory stress conditions makes postprandial stress an important factor involved in the development of cardiovascular risk factors. A large body of evidence have been accumulated on the anti-inflammatory effects of probiotics, but no information is available on the mechanisms through which intestinal microbiota modulates redox unbalance associated with inflammatory stress. Here, we aimed to investigate the ability of Lactobacillus casei Shirota (LS) to induce an antioxidant response to counteract oxidative and inflammatory stress in an in vitro model of enterocytes. Our results show that pretreatment of enterocytes with LS prevents membrane barrier disruption and cellular reactive oxygen species (ROS) accumulation inside the cells, modulates the expression of the gastro-intestinal glutathione peroxidase (GPX2) antioxidant enzyme, and reduces p65 phosphorylation, supporting the involvement of the Nfr2 and nuclear factor kappa B pathways in the activation of antioxidant cellular defenses by probiotics. These results suggest, for the first time, a redox mechanism by LS in protecting intestinal cells from AAPH-induced oxidative and inflammatory stress.

Effect of Sulfites on Antioxidant Activity, Total Polyphenols, and Flavonoid Measurements in White Wine.

Polyphenols content and antioxidant activity are directly related to the quality of wine. Wine also contains sulfites, which are added during the winemaking process. The present study aimed to evaluate the effects of sulfites on the assays commonly used to measure the antioxidant activity and polyphenols and flavonoids content of white wines. The effects of sulfites were explored both in the standard assays and in white wine. The addition of sulfites (at 1-10 µg) in the standard assays resulted in a significant, positive interference in the Folin-Ciocalteu's assay used for polyphenols measurements and in both the Ferric Reducing Antioxidant Power and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation decolorization assays, which were used for antioxidant activity evaluation. A negative interference of sulfites (at 1-20 µg) was observed for the colorimetric aluminium-chloride flavonoids assay. The addition of sulfites to organic white wines (at 25-200 mg/L wine) clearly resulted in a significant overestimation of antioxidant activity and polyphenols content, and in an underestimation of flavonoids concentration. To overcome sulfite interferences, white wines were treated with cross-linked polyvinylpyrrolidone. The total polyphenols content and antioxidant activity measurements obtained after polyvinylpyrrolidone treatment were significantly lower than those obtained in the untreated wines. Flavonoids were expected to be higher after polyvinylpyrrolidone treatment, but were instead found to be lower than for untreated wines, suggesting that in addition to sulfites, other non-phenolic reducing compounds were present in white wine and interfered with the flavonoid assay. In view of our results, we advise that a purification procedure should be applied in order to evaluate the quality of white wine.

The Potential Health Benefits of Polyphenol-Rich Extracts from Cichorium intybus L. Studied on Caco-2 Cells Model.

Phytochemicals can exert their bioactivity without reaching the systemic circulation; scarcely absorbed antioxidants might reach the large bowel contributing to protection from oxidative damage-induced gastrointestinal diseases. In the present work, we aimed to study the relationship between potential activity of polyphenol-rich extracts from Cichorium intybus L. and changes in morphological characteristics on Caco-2 cells. Phytochemicals content (carotenoids and flavonoids) and total antioxidant activity of Red Chicory of Treviso and Variegated Chicory of Castelfranco were evaluated. The bioactivity of polyphenol-rich extracts from chicories was studied in in vitro Caco-2 cell monolayers model. Morphological characteristics changes to test the antioxidant and/or prooxidant effect were verified by histological analysis and observed by Electronic Scansion Microscopy (SEM). On Caco-2 cell model, the polyphenols fractions from chicories have indicated a moderate antioxidant behavior until 17 µM concentration, while 70 µM and 34 µM exert cytotoxic effects for Treviso's and Castelfranco's Chicory, respectively, highlighted by TEER decreasing, increased permeability, and alteration of epithelium. Our findings support the beneficial effects of these products in counteracting the oxidative stress and cellular damage, induced in vitro on Caco-2 cell model, through interaction with the mucopolysaccharide complexes in the glycocalyx, maintaining in vivo a healthy and effective intestinal barrier.

Polyphenols content, phenolics profile and antioxidant activity of organic red wines produced without sulfur dioxide/sulfites addition in comparison to conventional red wines.

Wine exerts beneficial effects on human health when it is drunk with moderation. Nevertheless, wine may also contain components negatively affecting human health. Among these, sulfites may induce adverse effects after ingestion. We examined total polyphenols and flavonoids content, phenolics profile and antioxidant activity of eight organic red wines produced without sulfur dioxide/sulfites addition in comparison to those of eight conventional red wines. Polyphenols and flavonoids content were slightly higher in organic wines in respect to conventional wines, however differences did not reach statistical significance. The phenolic acids profile was quite similar in both groups of wines. Antioxidant activity was higher in organic wines compared to conventional wines, although differences were not statistically significant. Our results indicate that organic red wines produced without sulfur dioxide/sulfites addition are comparable to conventional red wines with regard to the total polyphenols and flavonoids content, the phenolics profile and the antioxidant activity.

Prevention of TNBS-induced colitis by different Lactobacillus and Bifidobacterium strains is associated with an expansion of gammadeltaT and regulatory T cells of intestinal intraepithelial lymphocytes.

BACKGROUND: Probiotics may protect against inflammatory bowel disease through regulation of lamina propria lymphocytes (LPLs) function. Data are lacking on possible involvement of intraepithelial lymphocytes (IELs). The aim of this study was to investigate whether different probiotic mixtures prevented gut inflammatory disease and the role of both IELs and LPLs. METHODS: BALB/c mice received 2 probiotic mixtures orally for 3 weeks, as Mix1 (Lactobacillus acidophilus and Bifidobacterium longum), or Mix2 (Lactobacillus plantarum, Streptococcus thermophilus, and Bifidobacterium animalis subsp. lactis). Colitis was induced by intrarectal administration of trinitrobenzene sulfonic acid (TNBS). Probiotics in stools were analyzed by real-time polymerase chain reaction (PCR). Colon subpopulations of IELs and LPLs were assayed by flow cytometry. Serum cytokines were measured by cytometric bead array (CBA). RESULTS: All probiotics colonized the intestine. The 2 mixtures prevented the TNBS-induced intestinal damage, and Mix1 was the most effective. The Mix1 protection was associated with a reduction in CD4(+) cells of IELs and LPLs, an increase in gammadeltaT cells of IELs, and a decrease in gammadeltaT cells of LPLs. An expansion of T regulatory (Treg) cells of IELs was induced by Mix1 and Mix2. Both probiotic mixtures inhibited tumor necrosis factor (TNF)-alpha and monocyte chemotactic protein (MCP)-1 production and upregulated interleukin (IL)-10. In addition, Mix1 prevented the TNBS-induced increase of IL-12 and interferon (IFN)-gamma. CONCLUSIONS: The 2 probiotic mixtures were able to prevent the TNBS-induced colitis; the L. acidophilus and B. longum mixture was the most effective. Other than an involvement of LPLs, our results report a novel importance of the IELs population in probiotic protection.

Zinc oxide protects cultured enterocytes from the damage induced by Escherichia coli.

There is some evidence that zinc oxide (ZnO) protects against intestinal diseases. However, despite the suggestions that ZnO may have an antibacterial effect, the mechanisms of this protective effect have not yet been elucidated. We investigated the potential benefits of ZnO in protecting intestinal cells from damage induced by enterotoxigenic Escherichia coli (ETEC, strain K88) and the related mechanisms, using human Caco-2 enterocytes. Cell permeability, measured as transepithelial electrical resistance (TEER), was unaffected by 0.01 and 1 mmol/L ZnO treatments and moderately increased by 5 mmol/L ZnO, compared with untreated cells. Transfer of (14)C-inulin was slightly increased by 5 mmol/L ZnO compared with untreated cells; transfer was unaffected by lower concentrations. The TEER and (14)C-inulin transfer were lower in ETEC-infected cells than in uninfected cells. Treatment of ETEC exposure with 0.2 mmol/L ZnO prevented disruption of membrane integrity. The ETEC was able to adhere to enterocytes and, to some extent, invade the cells. The ZnO treatment reduced bacterial adhesion and blocked bacterial invasion. The ETEC infection upregulated the expression of the inflammatory cytokines interleukin-8, growth-related oncogene-alpha and tumor necrosis factor-alpha, and reduced that of the anti-inflammatory cytokine transforming growth factor-beta, compared with uninfected cells. The addition of 0.2 or 1 mmol/L ZnO counteracted the alteration of cytokine mRNA levels caused by ETEC. The protective effects of ZnO were not due to any antibacterial activity, because the viability of ETEC grown in a medium containing ZnO was unaffected. In conclusion, ZnO may protect intestinal cells from ETEC infection by inhibiting the adhesion and internalization of bacteria, preventing the increase of tight junction permeability and modulating cytokine gene expression.