Pomegranates are one of the main highly valuable sources of ellagitannins. Despite the potential health benefits of these compounds, reliable data on their content in pomegranates and derived ...extracts and food products is lacking, as it is usually underestimated due to their complexity, diversity, and lack of commercially available standards. This study describes a new method for the analysis of the extractable and nonextractable ellagitannins based on the quantification of the acid hydrolysis products that include ellagic acid, gallic acid, sanguisorbic acid dilactone, valoneic acid dilactone, and gallagic acid dilactone in pomegranate samples. The study also shows the occurrence of ellagitannin C-glycosides in pomegranates. The method was optimized using a pomegranate peel extract. To quantify nonextractable ellagitannins, freeze-dried pomegranate fruit samples were directly hydrolyzed with 4 M HCl in water at 90 °C for 24 h followed by extraction of the pellet with dimethyl sulfoxide/methanol (50:50, v/v). The method was validated and reproducibility was assessed by means of an interlaboratory trial, showing high reproducibility across six laboratories with relative standard deviations below 15%. Their applicability was demonstrated in several pomegranate extracts, different parts of pomegranate fruit (husk, peels, and mesocarp), and commercial juices. A large variability has been found in the ellagitannin content (150–750 mg of hydrolysis products/g) and type (gallagic acid/ellagic acid ratios between 4 and 0.15) of the 11 pomegranate extracts studied.
The clinical evidence of dietary polyphenols as colorectal cancer (CRC) chemopreventive compounds is very weak. Verification in humans of tissue-specific molecular regulation by the intake of ...polyphenols requires complex clinical trials that allow for the procurement of sufficient pre- and postsupplementation tissue samples. Ellagitannins (ETs), ellagic acid (EA) and their gut microbiota-derived metabolites, the urolithins, modify gene expression in colon normal and cancer cultured cells. We conducted here the first clinical trial with 35 CRC patients daily supplemented with 900 mg of an ET-containing pomegranate extract (PE) and evaluated the expression of various CRC-related genes in normal and cancerous colon tissues before (biopsies) and after (surgical specimens) 5–35 days of supplementation. Tissues were also obtained from 10 control patients (no supplementation) that confirmed a large, gene- and tissue-specific interindividual variability and impact of the experimental protocol on gene expression, with some genes induced (MYC, CD44, CDKN1A, CTNNB1), some repressed (CASP3) and others not affected (KRAS). Despite these issues, the consumption of the PE was significantly associated with a counterbalance effect in the expression of CD44, CTNNB1, CDKN1A, EGFR and TYMs, suggesting that the intake of this PE modulated the impact of the protocol on gene expression in a gene- and tissue-specific manner. These effects were not associated with the individuals' capacity to produce specific urolithins (i.e., metabotypes) or the levels of urolithins and EA in the colon tissues and did not reproduce in vitro effects evidencing the difficulty of demonstrating in vivo the in vitro results.
Fas (CD95)/FasL (CD178) system during ageing Lagunas‐Rangel, Francisco A.
Cell biology international,
August 2023, 2023-Aug, 2023-08-00, 20230801, Volume:
47, Issue:
8
Journal Article
Peer reviewed
The Fas/FasL system plays a central role in the physiological regulation of apoptosis and has been implicated in the pathogenesis of several neoplasms and diseases of the immune system. Until now, it ...has received little attention in the context of ageing, but there is sufficient evidence that it plays an important role in this process and its deregulation favours the development of age‐related diseases such as osteoarthritis, diabetes, eye diseases, ischaemic processes, anaemia, Alzheimer's disease and cancer. With this in mind, the aim of this work was to describe the main changes that occur in the Fas/FasL system during ageing and their association with the development of age‐related diseases. Furthermore, it discusses how exercise and diet, considered the cornerstone of almost all healthy ageing programmes, produce beneficial effects through the regulation of the Fas/FasL system.
Primary prevention of cardiovascular disease (CVD) aims to avoid a first event in subjects that are at risk but have not yet been diagnosed with heart disease. Secondary prevention of CVD aims to ...avoid new events in patients with established heart disease. Both approaches involve clinical intervention and implementation of healthy lifestyles. The grape and wine polyphenol resveratrol (3,5,4′‐trihydroxy‐trans‐stilbene) has shown cardioprotective benefits in humans. Most of these approaches deal with rather high doses and short follow‐ups, and do not address the issue of long‐term resveratrol consumption safety, especially in medicated individuals. Here, we review the trials conducted with resveratrol in patients at risk for or with established CVD, focusing on the two longest human clinical trials reported so far (1‐year follow‐up). We also discuss the expectations for resveratrol from a dietary and clinical perspective in relation to CVD. However, statistically significant changes in CVD‐risk markers do not necessarily equal clinical significance in the daily care of patients.
Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of foodstuffs such as grapes and red wine. Resveratrol has been reported to exert ...a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol- based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of 'potential' benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called 'Resveratrol Paradox', i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently available evidence regarding resveratrol's effects on humans obtained from randomized clinical trials. In addition, we will provide a critical outlook for further research on this molecule that is evolving from a minor dietary compound to a possible multi-target therapeutic drug.
This study presents a methodology for compressing power system (PS) signals based on the Discrete Hartley Transform (DHT) and develops a computationally efficient approach for calculating power ...quality (PQ) parameters. Several algorithms are proposed for dynamic bit allocation for coefficient quantization of the DHT. The proposed algorithm was trialed on a real-world signal database and produced better results than those obtained using wavelet transforms. Several scenarios are investigated, and the comparative results are shown.
Basal and squamous cell carcinoma are the most common types of cancer in the United States and represent the vast majority of all cases of skin cancer; however, they rarely result in death or ...substantial morbidity, whereas melanoma skin cancer has notably higher mortality rates. In 2016, an estimated 76,400 US men and women will develop melanoma and 10,100 will die from the disease.
To update the 2009 US Preventive Services Task Force (USPSTF) recommendation on screening for skin cancer.
The USPSTF reviewed the evidence on the effectiveness of screening for skin cancer with a clinical visual skin examination in reducing skin cancer morbidity and mortality and death from any cause; its potential harms, including any harms resulting from associated diagnostic follow-up; its test characteristics when performed by a primary care clinician vs a dermatologist; and whether its use leads to earlier detection of skin cancer compared with usual care.
Evidence to assess the net benefit of screening for skin cancer with a clinical visual skin examination is limited. Direct evidence on the effectiveness of screening in reducing melanoma morbidity and mortality is limited to a single fair-quality ecologic study with important methodological limitations. Information on harms is similarly sparse. The potential for harm clearly exists, including a high rate of unnecessary biopsies, possibly resulting in cosmetic or, more rarely, functional adverse effects, and the risk of overdiagnosis and overtreatment.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of visual skin examination by a clinician to screen for skin cancer in adults (I statement).
Proanthocyanidins (PAs) were characterized in husk, membranes, arils, and seeds of ‘Mollar de Elche’ pomegranate cultivar using liquid chromatography–electrospray ionization–ion-trap tandem mass ...spectrometry after acid catalysis in the presence of phloroglucinol (phloroglucinolysis). PAs were also evaluated in commercial juice and in the juice made in the laboratory by pressing fresh arils. Pomegranate PAs were composed of a very rich mixture of flavan-3-ols: catechin, epicatechin, gallocatechin, epigallocatechin, epigallocatechin gallate, and epicatechin gallate. Catechins and gallocatechins were the most abundant units, while galloylated flavanols were detected at lower concentrations. The highest PA content was found in husk (1840.5 μg/g), followed by seeds (316.2 μg/g) and membranes (51.4 μg/g). With regard to the pomegranate edible parts, arils showed concentrations of 34.4 μg/g and pressed aril juice of 21.3 mg/L, lower than those found in other traditional PA-containing food and beverages, such as apple, grapes, chocolate, red wine, or tea. Higher concentrations similar to those found in red wine were observed in commercial whole fruit pressed pomegranate juice (146.9 mg/L). These PA concentrations represented between 0.1 and 7% of the total polyphenol content in the different pomegranate samples, which were richer in ellagitannins and anthocyanins. The mean degree of polymerization (1.2–2.1) revealed that PAs in Mollar pomegranate samples are constituted mainly of monomers and dimers, which may influence in better absorption and bioavailability of these compounds.
Many real-world systems can be studied in terms of pattern recognition tasks, so that proper use (and understanding) of machine learning methods in practical applications becomes essential. While ...many classification methods have been proposed, there is no consensus on which methods are more suitable for a given dataset. As a consequence, it is important to comprehensively compare methods in many possible scenarios. In this context, we performed a systematic comparison of 9 well-known clustering methods available in the R language assuming normally distributed data. In order to account for the many possible variations of data, we considered artificial datasets with several tunable properties (number of classes, separation between classes, etc). In addition, we also evaluated the sensitivity of the clustering methods with regard to their parameters configuration. The results revealed that, when considering the default configurations of the adopted methods, the spectral approach tended to present particularly good performance. We also found that the default configuration of the adopted implementations was not always accurate. In these cases, a simple approach based on random selection of parameters values proved to be a good alternative to improve the performance. All in all, the reported approach provides subsidies guiding the choice of clustering algorithms.
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