Antitumoral actions of Vismia baccifera on human hepatocellular carcinoma HepG2

195 p.Nowadays there is an increasing interest in finding bioactive compounds which can be used as chemopreventive agents against cancer. In this work, we have studied the antitumoral actions of aqueous extracts from leaves of the Colombian Amazonian Vismia baccifera plant on the human hepatocellular carcinoma HepG2 cell line. Our results showed that V. baccifera induced a cytotoxic response to HepG2, increasing the levels of mitochondrial O2- and intracellular ROS (particularly hydrogen peroxide), inducing depletion of GSH, cell cycle arrest at G2/M phase, endoplasmic reticulum stress, autophagy and apoptosis. Interestingly, the cytotoxic actions exerted by V. baccifera are exclusive of cancer cells. Hydrogen peroxide, whose intracellular accumulation was early induced by the extract, mediated the cytotoxic response. V. baccifera promoted deregulation of antioxidant enzymes, this effect being secondary to the accumulation of ROS. The intracellular GSH depletion was not the cause, but the consequence of V. baccifera-induced toxicity. The plant extract also affected HepG2 signaling by activating and inhibiting specific pathways. Moreover, we validated the experimental approach we have used to study the toxic response under conditions of 21% atmospheric pO2, ruling out any possible superimposed oxidative stress derived from the culture conditions. Our results highlight the importance of analyzing in depth the actions of this plant to generate knowledge that can lay the bases for coadjuvant or anti-cancer therapy

Activity of Pterostilbene Metabolites against Liver Steatosis in Cultured Hepatocytes

Pterostilbene is a dimethyl ether derivative of resveratrol, less metabolized than its analogue, due to the substitution of two hydroxyl groups with methoxyl groups. Nevertheless, the amounts of pterostilbene phase II metabolites found in plasma and tissues are higher than those of the parent compound. The first aim of this study was to assess whether pterostilbene-4′-O-glucuronide (PT-G) and pterostilbene-4′-O-sulfate (PT-S) were able to prevent triglyceride accumulation in AML12 (alpha mouse liver 12) hepatocytes. This being the case, we aimed to analyze the mechanisms involved in their effects. For this purpose, an in vitro model mimicking the hepatocyte situation in fatty liver was developed by incubating mouse AML12 hepatocytes with palmitic acid (PA). For cell treatments, hepatocytes were incubated with 1, 10 or 25 µM of pterostilbene, pterostilbene-4′-O-glucuronide or pterostilbene-4′-O-sulfate for 18 h. Triglycerides and cell viability were assessed by a commercial kit and crystal violet assay, respectively. Protein expression of enzymes and transporters involved in triglyceride metabolism was analyzed by immunoblot. The results showed for the first time the anti-steatotic effect of pterostilbene metabolites and thus, that they contribute to the preventive effect induced by pterostilbene on steatosis in in vivo models. This anti-steatotic effect is mainly due to the inhibition of de novo lipogenesis.This research was funded by Ministerio de Economía y Competitividad-Fondo Europeo de Desarrollo Regional (grant number AGL-2015-65719-R MINECO/FEDER, UE), Instituto de Salud Carlos III CIBERobn (grant number CB12/03/30007) and University of the Basque Country (grant number GIU 18/173)

Resveratrol Metabolites Are Able to Reduce Steatosis in Cultured Hepatocytes

Steatosis is characterized primarily by excessive lipid accumulation in the form of triglycerides in the liver. Although resveratrol shows a low bioavailability, it has significant positive effects on steatosis. The aim of this study was to analyze whether some phase II and microbial resveratrol metabolites (trans-resveratrol-4′-O-glucuronide (R-4G); trans-resveratrol-3-O-glucuronide (R-3G); trans-resveratrol-3-O-sulfate (R-S) and dihydro-resveratrol (DH-R) were effective in reducing hepatocyte fat accumulation. An in vitro model mimicking the hepatocyte situation in fatty liver was developed by incubating mouse AML12 hepatocytes with palmitic acid (PA). For cell treatments, hepatocytes were incubated with 1, 10, or 25 µM resveratrol or its metabolites. Triglycerides and cell viability were assessed using commercial kits. Protein expression of enzymes and transporters involved in triglyceride metabolism were analyzed by western blot. We show for the first time that resveratrol and all the tested metabolites, at 1 µM, partially prevented lipid accumulation induced by the saturated fatty acid PA in AML12 hepatocytes. This effect was mainly due to the inhibition of de novo lipogenesis. This demonstrates that the low bioavailability of resveratrol is not as big a problem as it was thought to be, because resveratrol metabolites contribute to the delipidating effects of the parent compound.This research was funded by Ministerio de Economía y Competitividad-Fondo Europeo de Desarrollo Regional, grant number AGL-2015-65719-R; Instituto de Salud Carlos III CIBERobn, grant number CB12/03/30007; University of the Basque Country, grant number GIU 18/173

Resveratrol and Pterostilbene, Two Analogue Phenolic Compounds, Affect Aquaglyceroporin Expression in a Different Manner in Adipose Tissue

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.This research has been supported by MINECO (AGL-2015-65719), Instituto de Salud Carlos III (CIBERobn) and Basque Government (IT-572-13; PA18/03)

Sexual Dimorphism in Brown Adipose Tissue Activation and White Adipose Tissue Browning

The present narrative review gathers the studies reported so far, addressing sex differences in the effects of cold exposure, feeding pattern and age on brown adipose tissue (BAT) thermogenesis and white adipose tissue (WAT) browning. In rodents, when exposed to decreasing temperatures, females activate thermogenesis earlier. Results obtained in humans go in the same line, although they do not provide results as solid as those obtained in rodents. Regarding the effects of overfeeding, interesting sex differences on BAT thermogenic capacity have been reported, and the greater or lower sensitivity of each sex to this dietary situation seems to be dependent on the type of feeding. In the case of energy restriction, females are more sensitive than males. In addition, sex differences have also been observed in thermogenesis changes induced by phenolic compound administration. During sexual development, an increase in BAT mass and BAT activity takes place. This phenomenon is greater in boys than in girls, probably due to its relation to muscle-mass growth. The opposite situation takes place during ageing, a lifespan period where thermogenic capacity declines, this being more acute in men than in women. Finally, the vast majority of the studies have reported a higher susceptibility to developing WAT browning amongst females. The scarcity of results highlights the need for further studies devoted to analysing this issue, in order to provide valuable information for a more personalised approach.This study was supported by Instituto de Salud Carlos III (CIBERobn) under Grant CB12/03/30007 and CB06/03/0025, and FIS PI20/00106 (co-funded by FEDER)

Sexual dimorphism in brown adipose tissue activation and white adipose tissue browning

The present narrative review gathers the studies reported so far, addressing sex differences in the effects of cold exposure, feeding pattern and age on brown adipose tissue (BAT) thermogenesis and white adipose tissue (WAT) browning. In rodents, when exposed to decreasing temperatures, females activate thermogenesis earlier. Results obtained in humans go in the same line, although they do not provide results as solid as those obtained in rodents. Regarding the effects of overfeeding, interesting sex differences on BAT thermogenic capacity have been reported, and the greater or lower sensitivity of each sex to this dietary situation seems to be dependent on the type of feeding. In the case of energy restriction, females are more sensitive than males. In addition, sex differences have also been observed in thermogenesis changes induced by phenolic compound administration. During sexual development, an increase in BAT mass and BAT activity takes place. This phenomenon is greater in boys than in girls, probably due to its relation to muscle-mass growth. The opposite situation takes place during ageing, a lifespan period where thermogenic capacity declines, this being more acute in men than in women. Finally, the vast majority of the studies have reported a higher susceptibility to developing WAT browning amongst females. The scarcity of results highlights the need for further studies devoted to analysing this issue, in order to provide valuable information for a more personalised approach

Beneficial Effects of Viable and Heat-Inactivated Lactobacillus rhamnosus GG Administration on Oxidative Stress and Inflammation in Diet-Induced NAFLD in Rats

Oxidative stress and inflammation are well-known triggers of NAFLD onset and progression. The aim of this study is to compare the potential benefits of a viable probiotic (Lactobacillus rhamnosus GG) and its parabiotic (heat-inactivated) on oxidative stress, inflammation, DNA damage and cell death pathways in the liver of rats featuring diet-induced NAFLD. The consumption of the steatotic diet led to increased final body and liver weights, higher hepatic triacylglycerol content, altered serum transaminase levels and enhanced oxidative and inflammatory status. Administration of the probiotic and the parabiotic partially prevented the body weight increase induced by the steatotic diet, whereas the probiotic caused more effective decreasing hepatic triglyceride content. Sharp but nonstatistically significant decreases in serum transaminase levels were also observed for both treatments. The reduction in antioxidant enzyme activities found in the nontreated animals fed the steatotic diet was partially prevented by both treatments (GPx activity). Similarly, the reductions in nonenzymatic antioxidant protection (GSH content) and total antioxidant capacity (ORAC) found in the nontreated rats were restored by the administration of both treatments. These results show that both viable and heat-inactivated Lactobacillus rhamnosus GG administration partially prevent steatotic diet-induced liver oxidative stress and inflammation induced in rats.This study was supported by Instituto de Salud Carlos III (CIBERobn) under Grant CB12/03/30007, The Basque Government under Grant IT1482-22 and Synergic R&D Projects in New and Emerging Scientific Areas on the Frontier of Science and Interdisciplinary Nature of The Community of Madrid (METAINFLAMATIONY2020/BIO-6600). Laura Isabel Arellano-García is a recipient of a doctoral fellowship from the Gobierno Vasco

Sexu-dimorfismoa gizakian: inplikazioak osasunean eta diagnostiko klinikoan

Sexu-dimorfismoa espezie bereko ar eta emeen arteko desberdintasun morfologiko eta fisiologikoei erreferentzia egiten dien terminoa da. Desberdintasun horiek sexu patroia material genetikora heredatu den moduaren arabera definituta egongo dira. Gaur egun komunitate zientifikoa ahalegin handia egiten ari da pertsonalizatutako zehaztasunezko medikuntza lortzeko, eta horretarako ezinbestekoa da patologia bakoitzaren kasuan sexuarekin lotura duten mekanismoak ondo ezagutzea. Era berean, sexuak gaixotasun baten sintomatologian, bilakaeran eta tratamenduarekiko erantzunean eragin ditzakeen desberdintasunak ulertzea ere garrantzitsua izango da aurrez aipatutako helburua lortuko bada. Horiek lortzen badira, patologia desberdinen prebentzio, diagnostiko eta tratamendu zehatz eta egokituagoak lortuko lirateke, kostu ekonomikoa handitu gabe, gainera. Dimorfismoak, sexuari lotutako patologiak ez ezik, sexuarekiko independenteak diren patologiei ere eragin diezaieke. Sexuari lotutako patologiei dagokienez, sexu-kromosometan adierazten da zein sexutan gertatzen diren gehien asaldurak, hemofilia edo daltonismoarekin gertatzen den bezala. Sexuari lotuta ez dauden patologia askotan, berriz, hainbat ikerketak desberdintasun handiak aurkitu dituzte horiek gizon eta emakumeetan duten eragiteko moduan ere. Esate baterako, gaixotasun kardiobaskularretan, sintoma klinikoak eta pronostikoa desberdinak dira bi sexuen artean, minbizi, hantura-gaixotasun eta gaixotasun neurologiko batzuetan gertatzen den bezala.; Sex-dimorphism refers to the different morphologic and physiologic characteristics present in subjects of the two sexes within the same species. Such differences are defined by the way in which the sex pattern has been inheritedinto the genetic material. Nowadays scientific community is making a huge effort in order to develop personalized precision medicine, and for that, understanding the mechanisms linked to sex that occur on different pathologies is of paramount interest. Similarly, it is also important to understand the potential differences that sex may exert in thesymtomatology and development of a disease, as well as the response of the patient to the prescribed treatment. If the aforementioned goals are achieved it would be possible to obtain a more precise prevention, diagnosis and treatment ofdifferent diseases. In this regard, it must be noted that sex not only affects to those pathologies that are linked to sex, but also to those that are independent of sex. In this line, in sex-related pathologies, it is defined in sexual chromosomes the extent in which each sex will be affected by the pathology, as occurs in haemophilia or daltonism. In the case of pathologies that are independent of sex, several studies have also found significant differences regarding the way inwhich such pathologies affect to both sexes. In this regard, the clinical symptoms and prognosis of cardiovascular diseases are different in men and women, as occurs with further pathologies such as cancer, inflammatory diseases or certain neurological disorders

Scientific Evidence Supporting the Beneficial Effects of Isoflavones on Human Health

Isoflavones are phenolic compounds with a chemical structure similar to that of estradiol. They are present in several vegetables, mainly in legumes such as soy, white and red clover, alfalfa and beans. The most significant food source of isoflavones in humans is soy-derived products. Isoflavones could be used as an alternative therapy for pathologies dependent on hormonal disorders such as breast and prostate cancer, cardiovascular diseases, as well as to minimize menopausal symptoms. According to the results gathered in the present review, it can be stated that there is scientific evidence showing the beneficial effect of isoflavones on bone health and thus in the prevention and treatment of osteoporosis on postmenopausal women, although the results do not seem entirely conclusive as there are discrepancies among the studies, probably related to their experimental designs. For this reason, the results should be interpreted with caution, and more randomized clinical trials are required. By contrast, it seems that soy isoflavones do not lead to a meaningful protective effect on cardiovascular risk. Regarding cancer, scientific evidence suggests that isoflavones could be useful in reducing the risk of suffering some types of cancer, such as breast and endometrial cancer, but further studies are needed to confirm these results. Finally, isoflavones could be useful in reducing hot flushes associated with menopause. However, a limitation in this field is that there is still a great heterogeneity among studies. Lastly, with regard to isoflavone consumption safety, it seems that they are safe and that the most common adverse effect is mild and occurs at the gastrointestinal level.This study was supported by Instituto de Salud Carlos III (CIBERobn) under Grant CB12/03/30007, Basque Government under Grant PA20/04 and the University of the Basque Country under Grant GIU18-17

Obesitateak minbizia izateko arriskua handitzen du… Zer mekanismo daude tartean?

Cancer is one of the most important public health problems of the last years, due to the fact that tumour incidence has increased dramatically over the last decade. Among other factors, the dietary pattern notably influences the development of cancer, as well as obesity and its comorbidities do. They increase the risk of developing several types of cancer: thyroid, esophagus, liver, gallbladder, colon, kidney and multiple myeloma cancer in men and women, breast and endometrium cancer in women and prostate cancer in men. However, the mechanism by which obesity can induce cancer has not been widely investigated. The known mechanisms that contribute to the association between cancer and obesity are related to hormonal changes, such as insulin and insulin-like growth hormone-1 (IGF-1), or sex steroids. Not only hormones can affect cancer development, but also adipokines (leptin and adiponectin) and inflammation. In the same way, patients with obesity and cancer have a higher risk of suffering metastasis, consequently having a lower survival rate. As pre-clinical research has shown, obesity can induce metastasis in melanoma and lung cancer models. Since it has been reported a relationship between obesity and a high mortality rate in oncological patients, it is essential to use drugs to treat obesity and metabolic syndrome in cancer patients, such as metformin, thiazolidinediones and statins. Finally, it is noteworthy to mention that further research is needed to better understand the mechanisms involved in this process, and even to find biomarkers that may be useful for an early cancer diagnosis.; Minbizia egungo osasun-arazo publiko garrantzitsuenetarikoa da; izan ere, tumoreen intzidentzia izugarri handitu da azken hamarkadetan. Beste faktore askoren artean, elikadura-patroiak nabarmen eragiten du minbiziaren garapenean; hala nola, obesitateak eta haren komorbilitateek. Hainbat minbizi mota garatzeko arriskua areagotzen dute, besteak beste gizon eta emakumezkoetan tiroide, hestegorri, gibel, behazun-besikula, kolon, giltzurrun eta mieloma anitzeko minbiziak, bular eta endometrioko minbiziak emakumezkoen kasuan eta prostatakoa gizonezkoenean. Azken urteetan nahiko ikertu da obesitatea-minbizia harremanean, baina oraindik ez dira ondorio garbiak lortu erlazio hori ezartzen duten mekanismo-multzoei dagokienez. Minbiziaren eta obesitatearen arteko asoziazioari laguntzen dioten mekanismoak aldaketa hormonalekin erlazionaturikoak izaten dira, besteak beste intsulina, intsulinaren antzekoa den 1 hazkuntza hormona (IGF-1) edo sexu esteroideak. Hormonak ez ezik, adipokinek (leptina eta adiponektina) eta hanturak ere parte hartzen dute minbiziaren garapenean.Era berean, obesitatea eta minbizia pairatzen duten pazienteek metastasi-arrisku handiagoa dute, eta ondorioz, biziraupen-ratio baxuagoa. Ikerketa pre-klinikoetan ikusi ahal izan denez, obesitateak metastasia bultzatzen du melanoma eta birika-minbizi ereduetan. Obesitateak paziente onkologikoen hilkortasun-tasa altuarekin duen lotura ikusita, ezinbestekotzat jotzen da minbizia duten pazienteetan, elikadura-patroi osasuntsuarekin eta jarduera fisikoarekin batera, obesitatea eta sindrome metabolikoa tratatzeko farmakoen erabilera; besteak beste, metformina, tiazolidinedionak eta estatinak erabili ohi dira. Amaitzeko, aipatzekoa da ikerlan gehiagoren beharra dagoela parte hartzen duten mekanismoak ondo ulertu ahal izateko, eta are gehiago, etorkizunean minbiziaren diagnostiko goiztiarrerako baliagarriak izan litezkeen bio-markatzaileak aurkitzeko