Showing papers by "Sabina Passamonti published in 2016"

Bilirubin is an Endogenous Antioxidant in Human Vascular Endothelial Cells.

Abstract: Bilirubin is a standard serum biomarker of liver function. Inexplicably, it is inversely correlated with cardiovascular disease risk. Given the role of endothelial dysfunction in originating cardiovascular diseases, direct analysis of bilirubin in the vascular endothelium would shed light on these relationships. Hence, we used high-performance liquid chromatography coupled with thermal lens spectrometric detection and diode array detection for the determination of endogenous cellular IXα-bilirubin. To confirm the isomer IXα-bilirubin, we used ultra-performance liquid chromatography coupled with a high-resolution mass spectrometer using an electrospray ionization source, as well as tandem mass spectrometric detection. We measured bilirubin in both arterial and venous rat endothelium (0.9-1.5 pmol mg(-1) protein). In the human endothelial Ea.hy926 cell line, we demonstrated that intracellular bilirubin (3-5 pmol mg(-1) protein) could be modulated by either extracellular bilirubin uptake, or by up-regulation of heme oxygenase-1, a cellular enzyme related to endogenous bilirubin synthesis. Moreover, we determined intracellular antioxidant activity by bilirubin, with EC50 = 11.4 ± 0.2 nM, in the range of reported values of free serum bilirubin (8.5-13.1 nM). Biliverdin showed similar antioxidant properties as bilirubin. We infer from these observations that intra-endothelial bilirubin oscillates, and may thus be a dynamic factor of the endothelial function.

Determination of cyanidin 3-glucoside in rat brain, liver and kidneys by UPLC/MS-MS and its application to a short-term pharmacokinetic study.

Abstract: Anthocyanins exert neuroprotection in various in vitro and in vivo experimental models. However, no details regarding their brain-related pharmacokinetics are so far available to support claims about their direct neuronal bioactivity as well as to design proper formulations of anthocyanin-based products. To gather this missing piece of knowledge, we intravenously administered a bolus of 668 nmol cyanidin 3-glucoside (C3G) in anaesthetized Wistar rats and shortly after (15 s to 20 min) we collected blood, brain, liver, kidneys and urine samples. Extracts thereof were analysed for C3G and its expected metabolites using UPLC/MS-MS. The data enabled to calculate a set of pharmacokinetics parameters. The main finding was the distinctive, rapid distribution of C3G in the brain, with an apparently constant plasma/brain ratio in the physiologically relevant plasma concentration range (19–355 nM). This is the first report that accurately determines the distribution pattern of C3G in the brain, paving the way to the rational design of future tests of neuroprotection by C3G in animal models and humans.

Epigenetic and miRNAs Dysregulation in Prostate Cancer: The role of Nutraceuticals.

Abstract: The control of cancer onset and progression is recognized to benefit from specific molecular targeting. MiRNAs are increasingly being implicated in prostate cancer, and the evidence suggests they are possible targets for molecular therapy and diagnosis. In cancer cells, growing attention has been dedicated to novel molecular mechanisms linking the epigenetic scenario to miRNA dysregulation. Currently, the rising evidence shows that nutritional and natural agents, the so-called nutraceuticals, could modulate miRNAs expression, and, as a consequence, might influence cellular responses in health or diseases conditions, including cancer. Among dietary components, plant-derived polyphenols are receiving wide interest, either for their anti-aging and anti-oxidant properties, or for their more general "cell-protective" effects. Above all, their role in preventing the occurrence/recurrence of cancer and, in particular, their potentiality in nutritional intervention for modulating the functions of miRNAs and the epigenetic mechanisms, is still under active debate. This review is focused on the more recent highlights of the impact of miRNAs dysregulation on the onset and progression of prostate cancer, their interplay with epigenetic control and their modulation by natural agents.

Effects of chlorogenic acid, caffeine and coffee on components of the purinergic system of streptozotocin-induced diabetic rats

Abstract: We evaluated the effect of chlorogenic acid (CGA), caffeine (CA) and coffee (CF) on components of the purinergic system from the cerebral cortex and platelets of streptozotocin-induced diabetic rats. Animals were divided into eight groups: control animals treated with (I) water (WT), (II) CGA (5 mg/kg), (III) CA (15 mg/kg) and (IV) CF (0.5 g/kg), and diabetic animals treated with (V) WT, (VI) CGA (5 mg/kg), (VII) CA (15 mg/kg) and (VIII) CF (0.5 g/kg). Our results showed an increase (173%) in adenosine monophosphate (AMP) hydrolysis in the cerebral cortex of diabetic rats. In addition, CF treatment increased adenosine diphosphate (ADP) and AMP hydrolysis in group VIII synaptosomes. Platelets showed an increase in ectonucleotidase activity in group V, and all treatments reduced the increase in adenosine triphosphate and ADP hydrolysis. Furthermore, there was an increase in platelet aggregation of 72% in the diabetic rats, and CGA and CF treatment reduced platelet aggregation by nearly 60% when compared to diabetic rats. In this context, we can suggest that CGA and CF treatment should be considered a therapeutic and scientific target to be investigated in diseases associated with hyperglycemia.

Phenolic composition of orange peels and modulation of redox status and matrix metalloproteinase activities in primary (Caco-2) and metastatic (LoVo and LoVo/ADR) colon cancer cells

Abstract: Orange (Citrus sinensis) peels, consumed in the diet as wines, candies or as infusions, are rich sources of phenolic compounds. This study sought to investigate the protective ability of phenolic extracts from orange peels against oxidative stress in primary human colonic tumor (Caco-2) and metastatic cell lines (LoVo and LoVo/ADR). The effects of the extracts on glutathione reductase, glutathione peroxidase and total matrix metalloproteinase (MMP) activities in the cells were also investigated. The results revealed that the extracts displayed cellular antioxidant activities and increased the activities of glutathione reductase and glutathione peroxidase in the cells. Furthermore, the extracts inhibited total MMP activities in the cells in a dose-dependent manner. HPLC fingerprinting revealed the presence of flavonoids and hydroxycinnamic acid. This study showed that orange peels phenolic extracts exhibited cellular antioxidant activity and inhibited MMP activity in colon cancer cells.

Flavonoid Interaction with a Chitinase from Grape Berry Skin: Protein Identification and Modulation of the Enzymatic Activity

Abstract: In the present study, an antibody raised against a peptide sequence of rat bilitranslocase (anti-peptide Ab) was tested on microsomal proteins obtained from red grape berry skin. Previously, this antibody had demonstrated to recognize plant membrane proteins associated with flavonoid binding and transport. Immuno-proteomic assays identified a number of proteins reacting with this particular antibody, suggesting that the flavonoid binding and interaction may be extended not only to carriers of these molecules, but also to enzymes with very different functions. One of these proteins is a pathogenesis-related (PR) class IV chitinase, whose in vitro chitinolytic activity was modulated by two of the most representative flavonoids of grape, quercetin and catechin, as assessed by both spectrophotometric and fluorimetric assays in grape microsomes and commercial enzyme preparations. The effect of these flavonoids on the catalysis and its kinetic parameters was also evaluated, evidencing that they determine a hormetic dose-dependent response. These results highlight the importance of flavonoids not only as antioxidants or antimicrobial effectors, but also as modulators of plant growth and stress response. Implications of the present suggestion are here discussed in the light of environment and pesticide-reduction concerns.

Biochemistry and physiology within the framework of the extended synthesis of evolutionary biology

Abstract: Functional biologists, like Claude Bernard, ask “How?”, meaning that they investigate the mechanisms underlying the emergence of biological functions (proximal causes), while evolutionary biologists, like Charles Darwin, asks “Why?”, meaning that they search the causes of adaptation, survival and evolution (remote causes). Are these divergent views on what is life? The epistemological role of functional biology (molecular biology, but also biochemistry, physiology, cell biology and so forth) appears essential, for its capacity to identify several mechanisms of natural selection of new characters, individuals and populations. Nevertheless, several issues remain unsolved, such as orphan metabolic activities, i.e., adaptive functions still missing the identification of the underlying genes and proteins, and orphan genes, i.e., genes that bear no signature of evolutionary history, yet provide an organism with improved adaptation to environmental changes. In the framework of the Extended Synthesis, we suggest that the adaptive roles of any known function/structure are reappraised in terms of their capacity to warrant constancy of the internal environment (homeostasis), a concept that encompasses both proximal and remote causes.