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The Mediterranean diet is a dietary pattern typical of the populations living in the Mediterranean basin during the 50s-60s of the last century. This diet has demonstrated beneficial effects in the prevention of several pathologies such as cardiovascular diseases, metabolic syndrome, or several cancer types, at least in part, due to its antioxidant compounds. Since the COVID-19 pandemic started, different authors have been studying the effects of certain dietary habits on the presence of COVID-19 and its severity, and the Mediterranean diet is one of them. This review gathers data from studies supporting the potential usefulness of the main phenolic compounds present in the Mediterranean diet, based on their antioxidant and anti-inflammatory effects, as preventive/therapeutic agents against COVID-19. The current evidence supports the potential benefits that hydroxytyrosol, resveratrol, flavonols such as quercetin, flavanols like catechins, and flavanones on the order of naringenin could have on COVID-19. This is due to the increase in the synthesis and translocations of Nrf-2, which increases the activity of antioxidant enzymes and thus reduces ROS production, the scavenging of free radicals, and the suppression of the activity of MMP-9, which is involved in the cytokine storm, and the inhibition of NF-κB.

Despite the general relationship between obesity and its co-morbidities, there are both obese individuals who scarcely present the associated pathologies (metabolically healthy obese; MHO) and individuals who present obesity alterations despite having normal weight (metabolically obese normal weight; MONW). It is still difficult to define metabolically MHO and MONW individuals because different classifications have been used in the studies reported. Indeed, different inclusion criteria have been used to discriminate between metabolically healthy and metabolically unhealthy subjects. Due to this and other reasons, such as differences in ethnicity, genetics, and lifestyle of the populations, data concerning the prevalence of MHO and MONW are very variable. The main determinants of MHO are type of growth (hypertrophy or hyperplasia), anatomical location, inflammation of adipose tissue, ectopic fat accumulation, genetic factors, and lifestyles factors. In the case of MONW, the main determinants are genetic background and lifestyle factors. With regard to treatment, it is not clear whether MHO subjects would benefit from traditional lifestyle interventions, based on diet energy restriction and increased physical activity. For MONW subjects, there is still no specialized treatment, and the therapies are the same as those used in obese subjects.

The main function of brown adipose tissue (BAT) is thermogenesis, a process mediated by uncoupling protein 1 (UCP1), which is located in the inner mitochondrial membrane and acts uncoupling oxidative phosphorylation from ATP production, thereby dissipating energy as heat. White adipose tissue can also express UCP1 positive cells due to a process known as browning. This phenomenon could also increase the thermogenic effect in the classical brown adipose depots. BAT thermogenesis depends, among other factors on both, nutritional conditions and food availability. Indeed, some studies have found that BAT recruitment and function are enhanced by some food components. The present study focuses on the effects of resveratrol and pterostilbene, two phenolic compounds belonging to the stilbene group, on BAT thermogenic activation and white adipose tissue browning process. The reported studies, carried out in cell cultures and animal models, show that both resveratrol and pterostilbene induce thermogenic capacity in interscapular BAT by increasing mitochondriogenesis, as well as enhancing fatty acid oxidation and glucose disposal. In addition, resveratrol seems to promote browning by activating peroxisome proliferator-activated receptor (PPAR), while the lack of changes in mitochondrial biogenesis suggests that probably the browning process occurs by direct resveratrol-mediated upregulation of ucp1 mRNA expression.

Consumption of high-energy-yielding diets, rich in fructose and lipids, is a factor contributing to the current increase in non-alcoholic fatty liver disease prevalence. Gut microbiota composition and short-chain fatty acids (SCFAs) production alterations derived from unhealthy diets are considered putative underlying mechanisms. This study aimed to determine relationships between changes in gut microbiota composition and SCFA levels by comparing rats featuring diet-induced steatohepatitis with control counterparts fed a standard diet. A high-fat high-fructose (HFHF) feeding induced higher body, liver and mesenteric adipose tissue weights, increased liver triglyceride content and serum transaminase, glucose, non-HDL-c and MCP-1 levels. Greater liver malondialdehyde levels and glutathione peroxidase activity were also observed after feeding the hypercaloric diet. Regarding gut microbiota composition, a lowered diversity and increased abundances of bacteria from the Clostridium sensu stricto 1, Blautia, Eubacterium coprostanoligenes group, Flavonifractor, and UBA1819 genera were found in rats featuring diet-induced steatohepatitis, as well as higher isobutyric, valeric and isovaleric acids concentrations. These results suggest that hepatic alterations produced by a hypercaloric HFHF diet may be related to changes in overall gut microbiota composition and abundance of specific bacteria. The shift in SCFA levels produced by this unbalanced diet cannot be discarded as potential mediators of the reported hepatic and metabolic alterations.

The present review is aimed at analysing the current evidence concerning the potential modulation of obesity and/or diet in adipose tissue ACE2. Additionally, the potential implications of these effects on COVID-19 are also addressed. The results published show that diet and obesity are two factors that effectively influence the expression of Ace2 gene in adipose tissue. However, the shifts in this gene do not always occur in the same direction, nor with the same intensity. Additionally, there is no consensus regarding the implications of increased adipose tissue ACE2 expression in health. Thus, while in some studies a protective role is attributed to ACE2 overexpression, other studies suggest otherwise. Similarly, there is much debate regarding the role played by ACE2 in COVID-19 in terms of degree of infection and disease outcomes. The greater risk of infection that may hypothetically derive from enhanced ACE2 expression is not clear since the functionality of the enzyme seems to be as important as the abundance. Thus, the greater abundance of ACE2 in adipose tissue of obese subjects may be counterbalanced by its lower activation. In addition, a protective role of ACE2 overexpression has also been suggested, associated with the increase in anti-inflammatory factors that it may produce., This research was funded by the University of the Basque Country under Grant GIU18-173 and CIBEROBN under Grant CB12/03/30007

Nephroblastoma overexpressed protein, also called NOV/CCN3, is an adipokine which is present in various tissues and recently linked to obesity. The objective of the study was to determine the effect of resveratrol and pterostilbene on NOV/CCN3 in adipose tissue from rats fed an obesogenic diet. Thirty-six male Wistar rats were split into four groups (n = 9): fed a standard diet (CC), high-fat high-sucrose (HFS) diet supplemented with resveratrol (RSV; 30 mg/kg/day) or with pterostilbene (PT; 30 mg/kg/day), or without phenolic supplementation (HFS). Rats were sacrificed after 6 weeks of treatment, and adipose tissue (white and brown) from different anatomical locations were dissected. Then, Nov/ccn3 gene and protein expression and the adipogenic genes, Ucp-1 and Pgc-1a, expressions were studied. Increased weight of white adipose tissues was found in rats fed the HFS diet. Whereas resveratrol-treated rats showed reduced internal and total adipose tissue weights, pterostilbene-treated rats showed reduced subcutaneous, internal and total adipose depots. Nov/ccn3 gene expression decreased in epididymal and interscapular brown depot in rats fed HFS diet when compared with the control group. Regarding the phenolic compounds, resveratrol prompted a Nov/ccn3 gene expression increase in epididymal fat tissue, whereas pterostilbene reduced its protein expression compared with the obese group. However, these phenolic compounds did not affect NOV/CCN3 expression in brown depot. NOV/CCN3 seems to be involved in weight changes in epididymal adipose tissue under obesogenic feeding, but not in subcutaneous, acting as a protective mechanism counteracting the fattening effect of the diet. To our knowledge, this is the first study analyzing whether NOV/CCN3 is involved in the anti-obesity effect of resveratrol and pterostilbene. Our results suggest that this is not the case.

The use of phenolic compounds as a new therapeutic approach against NAFLD has emerged recently. In the present study, we aim to study the effect of pterostilbene in the prevention of liver steatosis developed as a consequence of high-fat (saturated) high-fructose feeding, by analysing the changes induced in metabolic pathways involved in triglyceride accumulation. Interestingly, a comparison with the anti-steatotic effect of its parent compound resveratrol will be made for the first time. Rats were distributed into 5 experimental groups and fed either a standard laboratory diet or a high-fat high-fructose diet supplemented with or without pterostilbene (15 or 30 mg per kg per d) or resveratrol (30 mg per kg per d) for 8 weeks. Serum triglyceride, cholesterol, NEFA and transaminase levels were quantified. Liver histological analysis was carried out by haematoxylin-eosin staining. Different pathways involved in liver triglyceride metabolism, including fatty acid synthesis, uptake and oxidation, triglyceride assembly and triglyceride release, were studied. Pterostilbene was shown to partially prevent high-fat high-fructose feeding induced liver steatosis in rats, demonstrating a dose-response pattern. In this dietary model, it acts mainly by reducing de novo lipogenesis and increasing triglyceride assembly and release. Improvement in mitochondrial functionality was also appreciated. At the same dose, the magnitude of pterostilbene and resveratrol induced effects, as well as the involved mechanisms of action, were similar.

Non-alcoholic fatty liver disease (NAFLD) is considered the major cause for the development of chronic liver alterations. Hepatic steatosis is the most benign and common form of NAFLD, although its potential to evolve into more detrimental liver alterations makes its treatment necessary. In this regard, much attention has been paid to polyphenols, with resveratrol being one of the most studied ones. This review is aimed at studying the effects induced by resveratrol on hepatic steatosis in both preclinical studies conducted under different feeding conditions (overfeeding, normal feeding and caloric restriction), and in clinical trials. The vast majority of studies have been conducted by administering the polyphenol at the same time as an obesogenic diet. Under these experimental conditions, resveratrol has shown effectiveness improving diet-induced excessive liver lipid accumulation. Data are scarce for studies carried out by administering resveratrol under standard or energy-restricted feeding conditions. In this regard, while resveratrol retains its effectiveness, ameliorating hepatic steatosis under standard feeding conditions, such an effect has not been reported for the administration of the polyphenol under energy restriction. With regard to clinical trials, in the majority of them, resveratrol did not show its effectiveness in improving hepatic steatosis. This lack of effect could be due to significant differences in the experimental procedures (mainly the length of the experimental period). The relevance of liver fat content at the baseline should also be considered. Altogether, there is no sufficient scientific support so far for proposing resveratrol as a tool for hepatic steatosis treatment. This study has been supported by grants from Ministerio de Economia y Competitividad-Fondo Europeo de Desarrollo Regional, under grant AGL-2015-65719-R MINECO/FEDER, (UE), Instituto de Salud Carlos III (CIBERobn) under Grant CB12/03/30007 and University of the Basque Country, under Grant GIU18-173.

This review deals with the relationship among nutrition, the immune system, and coronavirus disease 2019 (COVID-19). The influence of nutrients and bioactive molecules present in foodstuffs on immune system activity, the influence of COVID-19 on the nutritional status of the patients, and the dietary recommendations for hospitalized patients are addressed. Deficient nutritional status is probably due to anorexia, nausea, vomiting, diarrhea, hypoalbuminemia, hypermetabolism, and excessive nitrogen loss. There is limited knowledge regarding the nutritional support during hospital stay of COVID-19 patients. However, nutritional therapy appears as first-line treatment and should be implemented into standard practice. Optimal intake of all nutrients, mainly those playing crucial roles in immune system, should be assured through a diverse and well-balanced diet. Nevertheless, in order to reduce the risk and consequences of infections, the intakes for some micronutrients may exceed the recommended dietary allowances since infections and other stressors can reduce micronutrient status. In the case of critically ill patients, recently published guidelines are available for their nutritional management. Further, several natural bioactive compounds interact with the angiotensin-converting enzyme 2 (ACE2) receptor, the gateway for severe acute respiratory syndrome (SARS) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Natural bioactive compounds can also reduce the inflammatory response induced by SARS-CoV-2. These compounds are potential beneficial tools in the nutritional management of COVID-19 patients. This research was supported by Instituto de Salud Carlos III (CIBERobn) and University of the Basque Country (GIU18-173).

This study was designed to analyze the anti-adipogenic effect of fifteen phenolic compounds from various chemical groups in 3T3-L1 pre-adipocytes. Cells were treated with 25 μM, 10 μM or 1 μM of apigenin, luteolin, catechin, epicatechin, epigallocatechin, genistein, daizein, naringenin, hesperidin, quercetin, kaempferol, resveratrol, vanillic acid, piceatannol and pterostilbene for 8 days. At 25 μM lipid accumulation was reduced by all the compounds, with the exception of catechin, epicatechin and epigallocatechin. At a dose of 10 μM apigenin, luteolin, naringenin, hesperidin, quercetin and kaempferol induced significant reductions, and at 1 μM only naringenin, hesperidin and quercetin were effective. The expression of c/ebpα was not. C/ebpβ was significantly reduced by genistein and kaempferol, pparγ by genistein and pterostilbene, srebp1c by luteolin, genistein, hesperidin, kaempferol, pterostilbene and vanillic acid, and lpl by kaempferol. In conclusion, the most effective phenolic compounds are naringenin, hesperidin and quercetin. Differences were found in terms of effects on the expression of genes involved in adipogenesis among the analyzed compounds.

Obesity and related comorbidities are a major health concern. The drugs used to treat these conditions are largely inadequate or dangerous, and a well-researched approach based on nutraceuticals would be highly useful. Pterostilbene (Pt), i.e., 3,5-dimethylresveratrol, has been reported to be effective in animal models of obesity, acting on different metabolic pathways. We investigate here its ability to induce browning of white adipose tissue. Pt (5 &micro, M) was first tested on 3T3-L1 mature adipocytes, and then it was administered (352 &micro, mol/kg/day) to mice fed an obesogenic high-fat diet (HFD) for 30 weeks, starting at weaning. In the cultured adipocytes, the treatment elicited a significant increase of the levels of Uncoupling Protein 1 (UCP1) protein&mdash, a key component of thermogenic, energy-dissipating beige/brown adipocytes. In vivo administration antagonized weight increase, more so in males than in females. Analysis of inguinal White Adipose Tissue (WAT) revealed a trend towards browning, with significantly increased transcription of several marker genes (Cidea, Ebf2, Pgc1&alpha, PPAR&gamma, Sirt1, and Tbx1) and an increase in UCP1 protein levels, which, however, did not achieve significance. Given the lack of known side effects of Pt, this study strengthens the candidacy of this natural phenol as an anti-obesity nutraceutical.

Aquaglyceroporins (AQPs) are transmembrane channels that mediate glycerol release and glycerol uptake. They are involved in fat metabolism, with implications in obesity. The aim was to determine whether the administration of resveratrol and pterostilbene during the six weeks of the experimental period would modify AQPs expression in white and brown adipose tissues from Wistar rats fed an obesogenic diet, and to establish a potential relationship with the delipidating properties of these compounds. Consequently, thirty-six rats were divided into four groups: (a) group fed a standard diet, and three more groups fed a high-fat high-sucrose diet: (b) high-fat high-sucrose group: (c) pterostilbene-treated group (30 mg/kg/d): (d) resveratrol-treated group (30 mg/kg/d). Epididymal, subcutaneous white adipose tissues and interscapular brown adipose tissue were dissected. AQPs gene expression (RT-PCR) and protein expression (western-blot) were measured. In white adipose tissue, pterostilbene reduced subcutaneous adipose tissue weight and prevented the decrease in AQP9 induced by obesogenic feeding, and thus glycerol uptake for triglyceride accumulation. Resveratrol reduced epididymal adipose tissue weight and avoided the decrease in AQPs related to glycerol release induced by high-fat high-sucrose feeding, suggesting the involvement of lipolysis in its body-fat lowering effect. Regarding brown adipose tissue, AQP7 seemed not to be involved in the previously reported thermogenic activity of both phenolic compounds.

Phenelzine has been suggested to have an antiobesity effect by inhibiting de novo lipogenesis, which led us to investigate the metabolic effects of oral chronic phenelzine treatment in high-sucrose-drinking mice. Sucrose-drinking mice presented higher body weight gain and adiposity versus controls. Phenelzine addition did not decrease such parameters, even though fat pad lipid content and weights were not different from controls. In visceral adipocytes, phenelzine did not impair insulin-stimulated de novo lipogenesis and had no effect on lipolysis. However, phenelzine reduced the mRNA levels of glucose transporters 1 and 4 and phosphoenolpyruvate carboxykinase in inguinal white adipose tissue (iWAT), and altered circulating levels of free fatty acids (FFA) and glycerol. Interestingly, glycemia was restored in phenelzine-treated mice, which also had higher insulinaemia. Phenelzine-treated mice presented higher rectal temperature, which was associated to reduced mRNA levels of uncoupling protein 1 in brown adipose tissue. Furthermore, unlike sucrose-drinking mice, hepatic malondialdehyde levels were not altered. In conclusion, although de novo lipogenesis was not inhibited by phenelzine, the data suggest that the ability to re-esterify FFA is impaired in iWAT. Moreover, the effects on glucose homeostasis and oxidative stress suggest that phenelzine could alleviate obesity-related alterations and deserves further investigation in obesity models., This study was partly supported by the DIOMED project (INTERREG IVB SUDOE 1/P1/E178).

This study aims to determine whether pterostilbene improves glycaemic control in rats showing insulin resistance induced by an obesogenic diet. Rats were divided into 3 groups: the control group and two groups treated with either 15 mg kg(-1) d(-1) (PT15) or 30 mg kg(-1) d(-1) of pterostilbene (PT30). HOMA-IR was decreased in both pterostilbene-treated groups, but this reduction was greater in the PT15 group (-45% and -22% respectively vs. the control group). The improvement of glycaemic control was not due to a delipidating effect of pterostilbene on skeletal muscle. In contrast, GLUT4 protein expression was increased (+58% and +52% vs. the control group), suggesting an improved glucose uptake. The phosphorylated-Akt/total Akt ratio was significantly enhanced in the PT30 group (+25%), and therefore a more efficient translocation of GLUT4 is likely. Additionally, in this group the amount of cardiotrophin-1 was significantly increased (+65%). These data suggest that the effect of pterostilbene on Akt is mediated by this cytokine. In the liver, glucokinase activity was significantly increased only in the PT15 group (+34%), and no changes were observed in glucose-6-phosphatase activity. The beneficial effect of pterostilbene on glycaemic control was more evident with the lower dose, probably because in the PT15 group both the muscle and the liver were contributing to this effect, but in the PT30 group only the skeletal muscle was responsible. In conclusion, pterostilbene improves glycaemic control in rats showing insulin resistance induced by an obesogenic diet. An increase in hepatic glucokinase activity, as well as in skeletal muscle glucose uptake, seems to be involved in the anti-diabetic effect of this phenolic compound.

Background Adipocytes derived from human mesenchymal stem cells (MSCs) are widely used to investigate adipogenesis. Taking into account both the novelty of these MSCs and the scarcity of studies focused on the effects of phenolic compounds, the aim of the present study was to analyze the effect of apigenin, hesperidin and kaempferol on pre-adipocyte and mature adipocytes derived from this type of cells. In addition, the expression of genes involved in TG accumulation was also measured. Methods Pre-adipocytes were cultured from day 0 to day 8 and mature adipocytes for 48 h with the polyphenols at doses of 1, 10 and 25 µM. Results Apigenin did not show an anti-adipogenic action. Pre-adipocytes treated with hesperidin and kaempferol showed reduced TG content at the three experimental doses. Apigenin did not modify the expression of the main adipogenic genes (c/ebpβ, c/ebpα, pparγ and srebp1c), hesperidin inhibited genes involved in the three phases of adipogenesis (c/ebpβ, srebp1c and perilipin) and kaempferol reduced c/ebpβ. In mature adipocytes, the three polyphenols reduced TG accumulation at the dose of 25 µM, but not at lower doses. All compounds increased mRNA levels of atgl. Apigenin and hesperidin decreased fasn expression. The present study shows the anti-adipogenic effect and delipidating effects of apigenin, hesperidin and kaempferol in human adipocytes derived from hMSCs. While hesperidin blocks all the stages of adipogenesis, kaempferol only inhibits the early stage. Regarding mature adipocytes, the three compounds reduce TG accumulation by activating, at least in part, lipolysis, and in the case of hesperidin and apigenin, also by reducing lipogenesis. Conclusions The present study shows for the first time the anti-adipogenic effect and delipidating effect of apigenin, hesperidin and kaempferol in human adipocytes derived from MSCs for the first time.

Adipose tissue releases bioactive mediators called adipokines. This review focuses on the effects of omentin, vaspin, cardiotrophin-1, Tumor necrosis factor-like Weak Inducer of Apoptosis (TWEAK) and nephroblastoma overexpressed (NOV/CCN3) on obesity and diabetes. Omentin is produced by the stromal-vascular fraction of visceral adipose tissue. Obesity reduces omentin serum concentrations and adipose tissue secretion in adults and adolescents. This adipokine regulates insulin sensitivity, but its clinical relevance has to be confirmed. Vaspin is produced by visceral and subcutaneous adipose tissues. Vaspin levels are higher in obese subjects, as well as in subjects showing insulin resistance or type 2 diabetes. Cardiotrophin-1 is an adipokine with a similar structure as cytokines from interleukin-6 family. There is some controversy regarding the regulation of cardiotrophin-1 levels in obese -subjects, but gene expression levels of cardiotrophin-1 are down-regulated in white adipose tissue from diet-induced obese mice. It also shows anti-obesity and hypoglycemic properties. TWEAK is a potential regulator of the low-grade chronic inflammation characteristic of obesity. TWEAK levels seem not to be directly related to adiposity, and metabolic factors play a critical role in its regulation. Finally, a strong correlation has been found between plasma NOV/CCN3 concentration and fat mass. This adipokine improves insulin actions.

In recent years, microalgae have attracted great interest for their potential applications in nutraceutical and pharmaceutical industry as an interesting source of bioactive medicinal products and food ingredients with anti-oxidant, anti-inflammatory, anti-cancer, and anti-microbial properties. One potential application for bioactive microalgae compounds is obesity treatment. This review gathers together in vitro and in vivo studies which address the anti-obesity effects of microalgae extracts. The scientific literature supplies evidence supporting an anti-obesity effect of several microalgae: Euglena gracilis, Phaeodactylum tricornutum, Spirulina maxima, Spirulina platensis, or Nitzschia laevis. Regarding the mechanisms of action, microalgae can inhibit pre-adipocyte differentiation and reduce de novo lipogenesis and triglyceride (TG) assembly, thus limiting TG accumulation. Increased lipolysis and fatty acid oxidation can also be observed. Finally, microalgae can induce increased energy expenditure via thermogenesis activation in brown adipose tissue, and browning in white adipose tissue. Along with the reduction in body fat accumulation, other hallmarks of individuals with obesity, such as enhanced plasma lipid levels, insulin resistance, diabetes, or systemic low-grade inflammation are also improved by microalgae treatment. Not only the anti-obesity effect of microalgae but also the improvement of several comorbidities, previously observed in preclinical studies, has been confirmed in clinical trials.

Resveratrol is a naturally occurring polyphenol found in many dietary sources and red wine. Recognized as a cancer chemoprevention agent, an anti-inflammatory factor and an antioxidant molecule, resveratrol has been proposed as a potential anti-obesity compound and to be beneficial in diabetes. Most of the studies demonstrating the anti-adipogenic action of resveratrol were performed as long-term treatments on cultured preadipocytes. The aim of this study was to analyse the acute effects of resveratrol on glucose uptake and lipolysis in human mature adipocytes. Samples of subcutaneous abdominal adipose tissue were obtained from overweight humans and immediately digested by liberase. Fat cells were incubated (from 45 min to 4 h) with resveratrol 1 μM-1 mM. Then, glycerol release or hexose uptake was determined. Regarding lipolysis, the significant effects of resveratrol were found at 100 μM, consisting in a facilitation of isoprenaline stimulation and an impairment of insulin antilipolytic action. At 1 and 10 μM, resveratrol only tended to limit glucose uptake. Resveratrol 100 μM did not change basal glucose uptake but impaired its activation by insulin or by benzylamine. This inhibition was not found with other antioxidants. Such impairment of glucose uptake activation in fat cells may led to a reduced availability of glycerol phosphate and then to a decreased triacylglycerol assembly. Therefore, resveratrol increased triacylglycerol breakdown triggered by β-adrenergic activation and impaired lipogenesis. Consequently, our data indicate that resveratrol can be considered as limiting fat accumulation in human fat cells and further support its use for the mitigation of obesity.

This review focuses on the role of 5'-activated protein kinase (AMPK) in the effects of resveratrol (RSV) and some RSV derivatives on hepatic steatosis. In vitro studies, performed in different hepatic cell models, have demonstrated that RSV is effective in preventing liver TG accumulation by activating AMPK, due to its phosphorylation. These preventive effects have been confirmed in studies conducted in animal models, such as mice and rats, by administering the phenolic compound at the same time as the diet which induces TG accumulation in liver. The literature also includes studies focused on other type of models, such as animals showing alcohol-induced steatosis or even steatosis induced by administering chemical products. In addition to the preventive effects of RSV on hepatic steatosis, other studies have demonstrated that it can alleviate previously developed liver steatosis, thus its role as a therapeutic tool has been proposed. The implication of AMPK in the delipidating effects of RSV in in vivo models has also been demonstrated. This study was supported by grants from the Instituto de Salud Carlos III (CIBERObn), Government of the Basque Country (IT-572-13).

In this study, a method was developed for determination of the free concentration of 4-isobutylacetophenone, a toxic degradation product of ibuprofen, in river and sewage water samples from Sweden. Sample preparation and analysis were performed by a hollow-fibre microporous membrane liquid-liquid extraction (HF-MMLLE) set-up and gas chromatography-mass spectrometry (GC-MS), respectively. In this novel approach, only the liquid in the membrane pores is utilised for non-depleting extraction. Several parameters were studied, including: type of organic solvent, sample pH, and salt and humic acid content. The optimised method allowed the determination of the analyte at the ng L(-1) level in river and sewage water. A linear plot gave a correlation coefficient better than 0.992 and resulted in a limit of detection of 7 and 14 ng L(-1) for river and sewage water, respectively. The enrichment factor was over 2000 in the fibre and over 300 after dilution. The repeatability and reproducibility were better than 5% and 10%, respectively. For the first time, 4-isobutylacetophenone was found at free concentrations of 40 ng L(-1) or below in sewage waters, while it could not be quantified in a river downstream from a municipal sewage treatment plant.

Scientific research is constantly looking for new molecules to be used as functional ingredients to combat obesity. The aim of the present study was to analyse whether resveratrol and conjugated linoleic acid (CLA) together could reduce body fat more efficiently than their separate administration. Thirty-six male Wistar rats were randomly divided into four groups: controls rats (C), rats treated with resveratrol (RSV), rats treated with CLA (CLA) and rats treated with a combination of resveratrol and CLA (RSV+CLA). All rats were fed on an obesogenic diet. In RSV and RSV+CLA groups, the rats received 30 mg resveratrol/kg body weight/day. In CLA and RSV+CLA groups, an equimolecular mixture of trans-10,cis-12 and cis-9,trans-11 was added to the diet to reach 0.5% of the active isomer trans-10,cis-12. After 6 weeks of treatment, white adipose tissue from different anatomical locations was dissected and weighed. Serum triacylglycerols, total and HDL cholesterols, glucose, insulin, fructosamine and TNF-α were measured. A glucose tolerance test was also performed. Separately, resveratrol and CLA significantly reduced body fat but did not do so when combined: 20% in the RSV group and 18% in CLA group but 7% in the RSV+CLA group. Resveratrol reduced serum triacylglycerols. No differences were found among groups in serum cholesterol. Resveratrol, as well as the combination RSV+CLA, improved glycaemic control. These results demonstrate that the combination RSV+CLA reduces the effectiveness of each compound on body fat-lowering action, but it maintains the positive effect of resveratrol on glycaemic control. Consequently, this combination has no usefulness in obesity prevention.

In this study, a method was developed for determination of steroid hormones (17beta-estradiol, estrone, 17alpha-ethynylestradiol) in tap and sewage water samples from Sweden. Sample preparation and analysis were performed by a hollow-fibre microporous membrane liquid-liquid extraction (HF-MMLLE) set-up combined with gas chromatography-mass spectrometry (GC-MS). In this approach, only the organic liquid in the lumen (10microL) of the hollow-fibre membrane was utilised for depleting extraction. Several parameters were studied, including: type of organic solvent, sample pH, salt and humic acid content. The optimised method allowed the determination of the analyte at the low ngL(-1) level in tap and sewage water. A linear plot gave correlation coefficients better than 0.995 and resulted in a method limit of detection of 1.6, 3 and 10ngL(-1) for 17beta-estradiol, estrone, and 17alpha-ethynylestradiol, respectively, in sewage water. Enrichment factors were over 1400 after derivatisation. The repeatabilities at 50 and 600ngL(-1) were better than 10% and 6%, respectively.

Polychlorinated biphenyls (PCBs) in water were extracted with a rebuilt extraction unit using 47 mm C18 solid-phase extraction (SPE) disks. Three types of disks (SPEC, ENVI and Empore) were investigated for the extraction of seven PCBs from 11 reagent water spiked at two concentration levels (20 and 1000 ng/l). The Empore disks produced the best analyte recoveries (91-107% with R.S.D. of 1-8%) at the low concentration level and displayed no leaking tendency. Empore disks were therefore considered superior to ENVI and SPEC disks for the conditions outlined in this work. The obtained extracts were dried and purified in an additional clean-up step using custom-made columns containing Florisil and Na2SO4. For water containing large amounts of organic matter, a pre-filtration was included. Final analysis was carried out on a dual-column GC-electron-capture detection system with on-column injection. The optimised extraction method, including clean-up, was less time-consuming and used less hazardous organic solvents than conventional liquid-liquid extraction (LLE) methods. Recoveries were 92-102% with R.S.D. of 3-8%.