Administration time effect of dietary proanthocyanidins on the metabolome of Fischer 344 rats is sex- and diet-dependent.

Proanthocyanidins (PAs) are one of the most commonly ingested polyphenols in the human diet, with a wide range of beneficial health effects. Remarkably, PAs have been reported to influence core and peripheral clock genes expression, and their effects may change in a time-of-day dependent manner. Therefore, the aim of this study was to investigate whether the capacity of PAs to modulate the metabolome is conditioned by the time-of-day in which these compounds are consumed in a diet- and sex-dependent manner. To do this, a grape seed proanthocyanidin extract (GSPE) was administered to female and male Fischer 344 rats at ZT0 (in the morning) and ZT12 (at night) and the GSPE administration time effect was evaluated on clock genes expression, melatonin hormone and serum metabolite levels in a healthy and obesogenic context. The results showed an administration time effect of GSPE on the metabolome in a sex and diet-dependent manner. Specifically, there was an effect on amino acid, lipid and cholate metabolite levels that correlated with the central clock genes expression. Therefore, this study shows a strong influence of sex and diet on the PAs effects on the metabolome, modulated in turn by the time-of-day.

A multifunctional ingredient for the management of metabolic syndrome in cafeteria diet-fed rats.

The body weight-lowering properties of a multifunctional ingredient (MIX) based on conjugated linoleic acid at low doses, the flavonoids proanthocyanidins and anthocyanidins and the chicken feet hydrolysate Hpp11 have been previously reported. The aim of this study was to evaluate the effect of long-term administration of MIX on other cardiometabolic risk factors associated with metabolic syndrome (MetS) in rats fed a cafeteria diet (CAF). Male Wistar rats were fed CAF for 11 weeks, and during the last 3 weeks, animals were orally administered MIX or vehicle. Lipid tolerance tests were performed before and after MIX administration. At the end of the experimental period, serum and inguinal white adipose tissue (iWAT) metabolism were analyzed by metabolomics and biochemical approaches. The metabolite signature of serum and iWAT significantly changed after 3 weeks of MIX administration, suggesting an improvement in lipid and glucose homeostasis in these animals. In addition, MIX also exhibited significant antihypertensive properties. These results suggest that MIX could be a good candidate to ameliorate the cardiometabolic risk factors related to MetS.

Protein Cohabitation: Improving the Photochemical Stability of R-Phycoerythrin in the Solid State.

The poor photochemical stability of R-phycoerythrin (R-PE) has been a bottleneck for its broad-spectrum applications. Inspired by nature, we studied a sustainable strategy of protein cohabitation to enhance R-PE stability by embedding it in a solid matrix of gelatin. Both pure R-PE and fresh phycobiliprotein (PBP) extracts recovered from Gracilaria gracilis were studied. The incorporation of R-PE in the gelatin-based films (gelatin-RPE and gelatin-PBPs) has improved its photochemical stability for at least 8 months, the longest time period reported so far. These results were evidenced by not only absorption but also emission quantum yield measurements (Φ). Moreover, the photostability of gelatin-RPE films upon continuous excitation with an AM1.5G solar simulator was tested and found to remain stable for 23 h after initial decreasing up to 250 min. In the end, another approach was established to allow 100% photostability for a 3 h exposure to an AM1.5G solar simulator by doping the gelatin-based film including R-Phycoerythrin with n-propyl gallate stabilized with Tween 80, allowing their use as naturally based optically active centers in photovoltaic applications.

Beneficial Effects of a Low-dose of Conjugated Linoleic Acid on Body Weight Gain and other Cardiometabolic Risk Factors in Cafeteria Diet-fed Rats.

Conjugated linoleic acid (CLA) is a dietary supplement that has been shown to improve obesity. However, some authors have associated high doses of CLA supplementation with liver impairment and insulin resistance. The aim of this study was to assess whether the consumption of low doses of CLA maintained the beneficial effects on the main metabolic disturbances associated with metabolic syndrome (MetS) but prevented the occurrence of non-desirable outcomes associated with its consumption. Male Wistar rats, fed standard or cafeteria (CAF) diet for 12 weeks, were supplemented with three different low doses of CLA in the last three weeks. Both biochemical and H1 NMR-based metabolomics profiles were analysed in serum and liver. The consumption of 100 mg/kg CLA, but not doses of 200 and 300 mg/kg, ameliorated the increase in body weight gain as well as the serum concentrations of glucose, insulin, cholesterol, triglyceride, diglyceride, and total phospholipid induced by a CAF diet. In turn, CLA reverted the increase in lactate, alanine, and glucose concentrations in the liver of these animals, but enhanced hepatic cholesterol accumulation without any detrimental effect on liver function. In conclusion, a low dose of CLA corrected the adverse effects associated with MetS without compromising other metabolic parameters.

Dietary proanthocyanidins boost hepatic NAD(+) metabolism and SIRT1 expression and activity in a dose-dependent manner in healthy rats.

Proanthocyanidins (PACs) have been reported to modulate multiple targets by simultaneously controlling many pivotal metabolic pathways in the liver. However, the precise mechanism of PAC action on the regulation of the genes that control hepatic metabolism remains to be clarified. Accordingly, we used a metabolomic approach combining both nuclear magnetic resonance and mass spectrometry analysis to evaluate the changes induced by different doses of grape-seed PACs in the liver of healthy rats. Here, we report that PACs significantly increased the hepatic nicotinamide adenine dinucleotide (NAD(+)) content in a dose-dependent manner by specifically modulating the hepatic concentrations of the major NAD(+) precursors as well as the mRNA levels of the genes that encode the enzymes involved in the cellular metabolism of NAD(+). Notably, Sirtuin 1 (Sirt1) gene expression was also significantly up-regulated in a dose-response pattern. The increase in both the NAD(+) availability and Sirt1 mRNA levels, in turn, resulted in the hepatic activation of SIRT1, which was significantly associated with improved protection against hepatic triglyceride accumulation. Our data clearly indicates that PAC consumption could be a valid tool to enhance hepatic SIRT1 activity through the modulation of NAD(+) levels.

Studies on the Zn(II)-mediated electrophilic selenocyclization and elimination of 3,4-O-isopropylidene-protected hydroxyalkenyl sulfides: synthesis of a 2-phenylselenenyl glycal.

Herein, we describe a mild and efficient Zn(II)-mediated electrophilic selenocyclization reaction of readily available and stable 3,4-O-isopropylidene-protected hydroxyalkenyl sulfides to 2-deoxy-2-phenylselenenyl-1-thio-glycosides. This material was transformed into a 2-phenylselenenyl glycal in a controlled manner using an activation-elimination sequence.

Ética, tecnología y clínica / Ethics, technology and clinics

Con la aparición y desarrollo de la revolución científico-técnica en la medicina, se asiste a un severo deterioro de la relación médico-paciente, a un abandono creciente del interrogatorio, del examen físico y del conocimiento clínico, así como una utilización y dependencia irracional y excesiva de los análisis complementarios por parte de un gran número de médicos, que configuran un verdadero fetichismo de la tecnología. Todo ello tiene muy importantes y sensibles implicaciones éticas en la práctica médica. En el presente trabajo se analizan, sucintamente, algunas razones de este fenómeno; se abordan las relaciones entre la clínica y la tecnología, se enfatiza la importancia del conocimiento clínico como componente esencial del diagnóstico y guía imprescindible para la indicación de los exámenes complementarios, a la vez que se destaca el gran valor de los análisis de laboratorio, los cambios que se han producido en el proceso del razonamiento clínico y la definitiva complementariedad de la clínica y el laboratorio como los dos componentes principales del método clínico.

With the emergence and development of the scientific-technical revolution in medicine, one witnesses severe deterioration of the physician-patient relationship, increasing neglect of questioning, physical exam and clinical knowledge as well as irrational and excessive use of & dependence on supplementary tests by a high number of phusicians,all of which shapes a real fetishism of technology. The above-mentioned has very important and sensitive ethical implications in medical practice. The present paper concisely analyzed some reasons for this phenomenon; addressed the relations between clinics and technology and it emphasized the importance of the clinical knowledge as an essential component of diagnosis and indispensable guide to prescribe supplementary tests. At the same time, the article outlined the great value of lab tests, the changes that have occured in the process of clinical reasoning and how clinics and the lab complement each other as the two main components of the clinical method.

Ética, tecnología y clínica / Ethics, technology and clinics

Con la aparición y desarrollo de la revolución científico-técnica en la medicina, se asiste a un severo deterioro de la relación médico-paciente, a un abandono creciente del interrogatorio, del examen físico y del conocimiento clínico, así como una utilización y dependencia irracional y excesiva de los análisis complementarios por parte de un gran número de médicos, que configuran un verdadero fetichismo de la tecnología. Todo ello tiene muy importantes y sensibles implicaciones éticas en la práctica médica. En el presente trabajo se analizan, sucintamente, algunas razones de este fenómeno; se abordan las relaciones entre la clínica y la tecnología, se enfatiza la importancia del conocimiento clínico como componente esencial del diagnóstico y guía imprescindible para la indicación de los exámenes complementarios, a la vez que se destaca el gran valor de los análisis de laboratorio, los cambios que se han producido en el proceso del razonamiento clínico y la definitiva complementariedad de la clínica y el laboratorio como los dos componentes principales del método clínico(AU)