http://www.dietcan.net/docs/Polifenoles%20en%20alimentos%20y%20biodisponibilidad.pdf

Polyphenols: food sources and bioavailability

Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction

Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies

Polyphenols are secondary metabolites of plants and are generally involved in defense against ultraviolet radiation or aggression by pathogens. In the last decade, there has been much interest in the potential health benefits of dietary plant polyphenols as antioxidant. Epidemiological studies and associated meta-analyses strongly suggest that long term consumption of diets rich in plant polyphenols offer protection against development of cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases. Here we present knowledge about the biological effects of plant polyphenols in the context of relevance to human health.

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Plant Polyphenols as Dietary Antioxidants in Human Health and Disease

The mitochondrial permeability transition.

Direct determination of free bilirubin in serum at sub-nanomolar levels

Rat liver plasma membranes contain F(O)F(1) complexes (ecto-F(O)F(1)) displaying a similar molecular weight to the mitochondrial F(O)F(1) ATP synthase, as evidenced by Blue Native PAGE. Their ATPase activity was stably reduced in short-term extra-hepatic cholestasis. Immunoblotting and immunoprecipitation analyses demonstrated that the reduction in activity was not due to a decreased expression of ecto-F(O)F(1) complexes, but to an increased level of an inhibitory protein, ecto-IF(1), bound to ecto-F(O)F(1). Since cholestasis down regulates the hepatic uptake of HDL-cholesterol, and ecto-F(O)F(1) has been shown to mediate SR-BI-independent hepatic uptake of HDL-cholesterol, these findings provide support to the hypothesis that ecto-F(O)F(1) contributes to the fine control of reverse cholesterol transport, in parallel with SR-BI. No activity change of the mitochondrial F(O)F(1) ATP synthase (m-F(O)F(1)), or any variation of its association with m-IF(1) was observed in cholestasis, indicating that ecto-IF(1) expression level is modulated independently from that of ecto-F(O)F(1), m-IF(1) and m-F(O)F(1).

The ectopic FOF1 ATP synthase of rat liver is modulated in acute cholestasis by the inhibitor protein IF1

Bilitranslocase is a plasma membrane carrier localised at the vascular pole of the rat liver cell, where it mediates uptake of organic anions from the blood into the liver. This carrier is also present in the epithelium of the rat gastric mucosa, with similar molecular mass and functional properties. An immunohistochemical study reveals that both the mucus-secreting cells of the gastric pit and the H+-secreting parietal cells express bilitranslocase. These data point to a possible role of bilitranslocase and of its food-borne substrates (anthocyanins and nicotinic acid) in regulating the function and the permeability of the gastric mucosa.

Immunolocalisation of bilitranslocase in mucosecretory and parietal cells of the rat gastric mucosa.

Background: Bilirubin is a highly-hydrophobic tetrapyrrole which binds to plasma albumin. It is conjugated in the liver to glucuronic acid, and the water-soluble glucuronides are excreted in urine and bile. The membrane transporters of bilirubin diglucuronide are well-known. Still undefined are however the transporters performing the uptake of bilirubin from the blood into the liver, a process known to be fast and not rate-limited. The biological importance of this process may be appraised by considering that in normal adults 200-300 mg of bilirubin are produced daily, as a result of the physiologic turnover of hemoglobin and cellular cytochromes. Nevertheless, research in this field has yielded controversial and contradicting results. We have undertaken a systematic review of the literature, believing in its utility to improve the existing knowledge and promote further advancements. Methods: We have sourced the PubMed database until 30 June 2017 by applying 5 sequential searches. Screening and eligibility criteria were applied to retain research articles reporting results obtained by using bilirubin molecules in membrane transport assays in vitro or by assessing serum bilirubin levels in in vivo experiments. Results: We have identified 311 articles, retaining 44, reporting data on experimental models having 6 incremental increases of complexity (isolated proteins, membrane vesicles, cells, organ fragments, in vivo rodents, and human studies), demonstrating the function of 19 membrane transporters, encoded by either SLCO or ABC genes. Three other bilirubin transporters have no gene, though one, i.e., bilitranslocase, is annotated in the Transporter Classification Database. Conclusions: This is the first review that has systematically examined the membrane transporters for bilirubin and its conjugates. Paradoxically, the remarkable advancements in the field of membrane transport of bilirubin have pointed to the elusive mechanism(s) enabling bilirubin to diffuse into the liver as if no cellular boundary existed.

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Membrane Transporters for Bilirubin and Its Conjugates: A Systematic Review.

Red wine polyphenols (RWP) induce nitric oxide (NO) and endothelium-derived hyperpolarization (EDH)-mediated coronary vasodilatation involving the redox-sensitive PI3-kinase/Akt-dependent pathway in the endothelium. However, there is a gap of knowledge in explaining how bioactive polyphenols initialize their signalling pathway in endothelial cells. Here, we investigated the hypothesis that flavonoids act subsequently to their entry into the endothelium via the flavonoid membrane transporter bilitranslocase (TC 2.A.65.1.1). Thus, vascular reactivity studies were performed using isolated porcine coronary artery rings. We separately determined the NO- and EDH-mediated components of the relaxation in the presence of specific inhibitors. In either case, bilitranslocase antibodies significantly reduced the relaxations of coronary artery rings induced by RWP. Furthermore, bilitranslocase antibodies significantly reduced RWP-induced phosphorylation levels of Akt and eNOS, assessed in cultured endothelial cells from porcine coronary arteries by Western blot analysis. The present findings indicate that bilitranslocase-mediated membrane transport substantially contributes to the initial step of RWP-induced coronary vasodilatation.

Sabina Passamonti

Papers

Direct determination of free bilirubin in serum at sub-nanomolar levels

The ectopic FOF1 ATP synthase of rat liver is modulated in acute cholestasis by the inhibitor protein IF1

Immunolocalisation of bilitranslocase in mucosecretory and parietal cells of the rat gastric mucosa.

Membrane Transporters for Bilirubin and Its Conjugates: A Systematic Review.

Role of endothelial cell membrane transport in red wine polyphenols-induced coronary vasorelaxation: involvement of bilitranslocase