Joana M Planas

University of Barcelona | UB · Department of Biochemistry and Physiology

The Mediterranean Diet is associated with antihypertensive properties and prevention of cardiovascular disease. This dietary pattern includes the intake of Olea europaea L. derivatives such as extra virgin olive oil and table olives, characterized by a high content of bioactive compounds. Recently, it has been demonstrated that the supplementation...

The pharmacokinetics (PK) of hydroxytyrosol and its metabolites were characterized following oral administration to Sprague-Dawley rats of 3.85 and 7.70 g of destoned Arbequina table olives/kg. Plasma samples were analyzed using a fully validated method consisting of liquid extraction followed by liquid chromatography-tandem mass spectrometry (LC-M...

Arbequina table olive (AO) consumption lowers blood pressure (BP) in spontaneously hypertensive rats (SHR). This study evaluates whether dietary supplementation with AO induced changes in the gut microbiota that are consistent with the purported antihypertensive effects. Wistar-Kyoto rats (WKY-c) and SHR-c received water, while SHR-o were supplemen...

BACKGROUND Table olives are a food with a high content of bioactive compounds with cardioprotective properties, such as oleic acid, polyphenols, and pentacyclic triterpenes. Here, we investigate the effect of the intake of table olives on blood pressure (BP) and body weight in spontaneously hypertensive rats (SHR) and their normotensive controls, W...

Maslinic acid is a pentacyclic triterpene widely distributed in the plant kingdom and found in several edible vegetables and fruits, being table olives a rich source of this compound. Maslinic acid is being recognized as a nutraceutical due to its lack of harmful effects and numerous health-protecting properties. The present chapter reviews the cur...

The role attributed to polyphenols on human-health need to be correlated with their plasmatic concentrations after food consumption. Then, a method based on liquid-liquid extraction followed by highly sensitive LC-ESI-MS/MS analysis was developed to determinate 16 phenolic compounds in plasma. Validation gave appropriate recovery, matrix effect (80...

Pentacyclic triterpenes (PT) and polyphenols from two varieties of table olives, Arbequina and Empeltre, were determined using a unique extraction from the same olive samples prior to their analysis by LC-APCI-MS and LC-ESI-MS/MS, respectively. Validation provided linear correlation and high sensitivity, as well as adequate precision and accuracy (...

Table olives contain a wide range of polyphenols responsible for protective effects on health that have been associated with a lower prevalence of chronic diseases. A new method to identify and quantify these compounds in table olives, by means of methanol:ethanol (1:1; v/v) extraction followed by LC-ESI-MS/MS, has been developed and validated. The...

Maslinic acid triggers compelling antiproliferative and pro-apoptotic effects in different human cancer cell lines. Hence, the chemopreventive activity was investigated on early stages of carcinogenesis induced by 1,2-dimethylhydrazine (DMH) which is a model that mimics human sporadic colorectal cancer. Male Sprague-Dawley rats were orally administ...

Table olives are especially rich in pentacyclic triterpenic compounds, which exert several biological activities. A crucial step in order to know if these compounds could contribute to the beneficial and healthy properties of this food is their measurement in blood. Therefore, the present study describes a simple and accurate liquid-liquid extracti...

Scope: Maslinic acid has been described to exert a chemopreventive activity in colon cancer. Hereby, we determined maslinic acid and its metabolites in the rat intestine previous oral administration as a first step in elucidating whether this triterpene might be used as a nutraceutical. Methods and results: Maslinic acid was orally administered...

Pentacyclic triterpenes are gaining interest due to their beneficial health effects, as anti-inflammatory, anti-diabetic and anti-tumoral, among others. In this study, an analytical LC-MS method was developed for the simultaneous determination of maslinic, oleanolic and ursolic acids along with erythrodiol and uvaol, which are the main triterpenic...

Maslinic acid is a natural pentacyclic triterpenoid widely distributed in edible and medicinal plants with health-promoting activities. The identification and quantification of its metabolites is a requirement for a better understanding of the biological effects of this triterpene. Therefore, maslinic acid was orally administered to Sprague-Dawley...

ScopeMaslinic acid is a bioactive minor component of Olea europaea L. with health-enhancing activities and no harmful effects. A pharmacokinetic (PK) study was conducted to determine its bioavailability for future studies of maslinic acid in humans.Methods and ResultsIntravenous (1 mg/kg) and oral (50 mg/kg) administrations to Sprague-Dawley rats w...

Maslinic acid is a pentacyclic triterpene found in a variety of natural sources, ranging from herbal remedies used in traditional Asian medicine to edible vegetables and fruits present in the Mediterranean diet. In recent years, several studies have proved that maslinic acid exerts a wide range of biological activities, i.e. antitumor, antidiabetic...

Maslinic acid, a pentacyclic triterpene from Olea europaea L., exerts hypoglycemic, antioxidant, cardioprotective and antitumoral activities. Here, an LC-APCI-MS method to determine this compound in plasma is presented as a first step in pharmacokinetic studies. Maslinic acid was extracted from plasma with ethyl acetate and separated on a C18 colum...

Scope: Maslinic acid, the main pentacyclic triterpene of the cuticle of Olea europaea L. fruit, has multiple beneficial effects on health, most notably antitumor and hypoglycemic properties. Notwithstanding the biological activities, there is a lack of knowledge about its safety. Therefore, the purpose of this study was to evaluate whether high do...

Maslinic acid, a pentacyclic triterpene from olives, has been reported to exert beneficial effects on health, including anticarcinogenic activity. Despite its importance, little is known about its bioavailability in both humans and animals. A fundamental step for this evaluation consisted of measuring this compound in blood. Therefore, a simple hig...

trans-Resveratrol (trans-3,4',5-trihydroxystilbene) is a natural phytoalexin present in grapes, red wine, berries and peanuts with health protecting properties. The low oral bioavailability indicated for this polyphenol, with the intestine as a bottleneck to its absorption, has promoted the large intestine as a potential target site for its chemopr...

D-Fagomine is an iminosugar originally isolated from seeds of buckwheat (Fagopyrum sculentum Moench), present in the human diet and now available as a pure crystalline product. We tested D-fagomine for activities connected to a reduction in the risk of developing insulin resistance, becoming overweight and suffering from an excess of potentially pa...

Numerous steatotic livers are discarded for transplantation because of their poor tolerance of ischemia-reperfusion (I/R). The injurious effects of retinol-binding protein 4 (RBP4) in various pathologies are well documented. RBP4 levels are reduced by peroxisome proliferator-activated receptor-γ (PPARγ) agonists. Strategies aimed at increasing PPAR...

To develop a population pharmacokinetic (PK) model which allowed the simultaneous modeling of trans-resveratrol and its glucuronide and sulfate conjugates. Male Sprague-Dawley rats were administered i.v. and p.o. with 2, 10 and 20 mg·kg(-1) of trans-resveratrol. Blood was collected at different times during 24 h. An integrated PK model was develope...

Several aspects of the Mediterranean diet have been associated with a reduced risk not only of cardiovascular disease, but also of several cancers, and it has been suggested that up to 25% of colorectal, 15% of breast and 10% of prostate, pancreas, and endometrial cancers could be prevented by shifting to a Mediterranean lifestyle. Olive oil, a cen...

Colorectal cancer is the third most common form of cancer in both men and women, and the third leading cause of cancer-related death in the Western world, being usually lethal when diagnosed at later stages of progression. Diet and lifestyle are most likely related to colon cancer etiology through overconsumption of energy, coupled with inadequate...

trans-Resveratrol, a natural occurring polyphenol, has been described as an antiproliferative and proapoptotic agent in vitro. Here, we studied the effect of trans-resveratrol administered orally at a dose of 60 mg/kg for 49 days on early preneoplastic markers induced by the intraperitoneal injection of 1,2-dimethylhydrazine (20 mg/kg). We measured...

Dihydroresveratrol is a metabolite of trans-resveratrol formed in the intestine by the hydrogenation of the double bond by microflora. The aim of the present study was to validate a method to measure dihydroresveratrol in rat plasma and then to quantify its plasmatic concentration after the oral administration of 60 mg/kg to Sprague-Dawley rats. Di...

trans-Resveratrol, a natural antioxidant, has been described as a nutraceutic compound with important beneficial effects on health, but its low oral bioavailability hinders its therapeutic activity. Here, we studied the mechanisms of apical transport of trans-resveratrol in enterocytes and the role of ATP-binding cassette (ABC) transporters in the...

trans-Resveratrol undergoes extensive metabolism in the intestinal cells, which leads to the formation of glucuronide and sulfate conjugates. Given the important role of the breast cancer resistance protein (ABCG2/BCRP) in the efflux of conjugated forms, the present study investigates the bioavailability and tissue distribution of trans-resveratrol...

trans-Resveratrol, a polyphenol from grapes, is being recognized as a bioactive agent with potential beneficial effects on health. However, little is known about its distribution in the organism mainly because of the lack of accurate and precise detection methods. Consequently the aim of the present study was to develop a methodology of extraction...

Sodium tungstate reduces glycemia and reverts the diabetic phenotype in several induced and genetic animal models of diabetes. Oral administration of this compound has recently emerged as an effective treatment for diabetes. Here we examined the effects of 30 days of oral administration of tungstate on disaccharidase and Na+/D-glucose cotransporter...

We have previously reported the anticarcinogenic effects of an olive fruit extract composed of pentacyclic triterpenes, the main components of which are maslinic acid (73.25%) and oleanolic acid (25.75%). Here we examined the effects of the individual components on proliferation, necrosis and apoptosis rates by fluorescence-based techniques in huma...

trans-Resveratrol is a polyphenol found in blueberries, grapes, and wine with cancer chemopreventive properties. The low bioavailability of this compound enhances its concentration in the luminal content and becomes a potential chemopreventive agent against colon cancer. In the present study, the antiproliferative and pro-apoptotic effects on the h...

Erythrodiol is the precursor of pentacyclic triterpenic acids present in Olea Europaea. Although olive oil and some of its constituents are reported to have anticarcinogenic activities, erythrodiol has not been assessed in its cell biological functions in detail. We therefore determined its effects on cell growth and apoptosis in human colorectal c...

Olives and their derivatives represent an important component of the Mediterranean diet that has been considered to be protective against cancer. We investigated the effect on cell proliferation and apoptosis in HT-29 cells of an extract from the skin of olives composed of pentacyclic triterpenes with the main components maslinic acid (73.25%) and...

Experimental models of hypertension, such as spontaneously hypertensive rats (SHR), show alterations in cellular sodium transport that affects Na(+)-coupled cotransport processes and has been involved in the pathogenesis of this disease. The objective of the present study was to analyze the kinetic properties of the sodium-dependent glucose transpo...

In chickens, elevated environmental temperature reduces food intake. We have previously reported that, during heat stress, the intestinal mucosa has an increased capacity to take up sugars. To investigate whether the effects of warm environment on sugar uptake are an intestinal adaptation to lower energy intake or a response attributable to heat st...

We investigated the intestinal transport of D-glucose (D-Glc) and 3 essential amino acids in a model of intestinal inflammation, and the effects of dietary supplementation with animal plasma proteins on this function. Wistar Lewis rats were fed a diet containing an isonitrogenous amount of milk protein (control group) or a diet supplemented with ei...

trans-Resveratrol was reported to have health benefits including anticarcinogenic effects and protection against cardiovascular disease. One of the mechanisms by which it exerts its action is through modulating the estrogen response systems. Because estrogen is involved in male reproductive biology, we investigated the effect of trans-resveratrol o...

Brush border membrane vesicles (BBMV) enriched in sucrase, maltase and alkaline phosphatase, and impoverished in Na+-K+-ATPase, were isolated from proximal and distal intestine of the gilthead sea bream (Sparus aurata) by a MgCl2 precipitation method. Vesicles were suitable for the study of the characteristics of D-glucose apical transport. Only on...

Abnormalities in carbohydrate metabolism and the insulin resistance status have been associated with hypertension. We have previously described alterations in the sodium-coupled sugar absorption in an experimental model of hypertension; in the present work, we studied the regulation of the sodium-independent, GLUT5-facilitated D-fructose intestinal...

In mammals, D-fructose transport takes place across the brush-border membrane of the small intestine through GLUT5, a member of the facilitative glucose transporter family. In the present paper, we describe and characterize for the first time the apical transport of D-fructose in chicken intestine. Brush-border membrane vesicles (BBMV) were obtaine...

The phytochemical trans-resveratrol present in peanuts, grapes, and red wine is well-known for its health protecting properties, such as cancer chemopreventive agent. The potential beneficial effects on health justify the study of the pharmacokinetic properties of this dietary component. The plasmatic trans-resveratrol time course was determined af...

Na+-dependent D-glucose transport was studied in brush-border membrane vesicles from duodenum, jejunum, and ileum of 5- to 6-wk-old chickens. Regional differences were found, and both initial rates and accumulation ratio of D-glucose were higher in the proximal part of the small intestine than in the ileum. To establish the mechanism(s) underlying...

Several beneficial effects on health have been reported for resveratrol (trans-3,4',5-trihidroxystilbene), naturally present in grapes and in a variety of medicinal plants. The aim of this study is to determine the effects on the intestinal enzymatic activities of the oral administration of 20 mg/kg of trans-resveratrol in Sprague-Dawley rats durin...

To evaluate the effect of age on sugar transport, we determined the uptake of methyl alpha-D-glucopyranoside and the abundance of the Na(+)-D-glucose cotransporter (SGLT1) in jejunal brush-border membrane (BBM) vesicles of 2-day- and 5-wk-old chickens. Methyl alpha-D-glucopyranoside transport per BBM protein was 40% lower in adults than in newly ha...

In the chicken intestine, the reduction in Na(+) intake led to a decrease in the transport of alpha-methyl-D-glucoside in the ileum (reduction of 42%) and in the rectum (51%). These reductions were reversed within 24 h after resalination and were inversely correlated to the changes in aldosterone plasma concentration. The reduction in intestinal he...

trans-3,5,4'-Trihydroxystilbene (trans-resveratrol) is a phytochemical present in peanuts, grapes and wine with beneficial effects such as protection against cardiovascular disease and cancer prevention. The purpose of this study was to evaluate whether high doses of trans-resveratrol have harmful effects on Sprague-Dawley rats. trans-Resveratrol w...

D-fructose transport was characterized in renal brush-border membrane vesicles (BBMVs) from both spontaneously hypertensive rats (SHR) and normotensive genetic control Wistar-Kyoto (WKY) rats. Kinetic studies indicated that the maximal rate (Vmax) of D-fructose transport was significantly lower in SHR compared with WKY rats. No differences were obs...

1. In chickens, low Na+ diets markedly decrease the hexose transport in the rectal segment of the large intestine; transport in the ileum shows a lower, but significant reduction and transport in the jejunum is unaffected. These effects involve both apical (SGLT1) and basolateral (GLUT2) hexose transporters. 2. The role of the renin-angiotensin-ald...

The lipid composition and fluidity in brush-border membrane vesicles (BBMV) isolated from renal cortex of spontaneously hypertensive rats (SHR) and their normotensive control, Wistar Kyoto (WKY) rats have been studied. The activity of Na+-dependent D-glucose transport has been also determined. A significant increase in total phospholipids and free...

Na+-dependent D-glucose and D-galactose transport was studied in the ileal brush-border membrane vesicles from both spontaneously hypertensive rats (SHR) and their normotensive genetic control Wistar-Kyoto (WKY) rats. Initial rates and accumulation ratios of the transport of both monosaccharides were significantly lower in the hypertensive rats com...

Ultrastructural studies on the epithelium, sugar transport and immunocytochemistry of Na+-glucose cotransporter (SGLT1) were carried out in the jejunum of Spontaneously Hypertensive Rats (SHR) and their normotensive genetic control, Wistar-Kyoto (WKY) rats. Electron microscopy studies showed a regular brush-border membrane in the jejunal enterocyte...

Hydroxytyrosol (2-(3,4-dihydroxyphenyl)ethanol), a phenolic compound present in extravirgin olive oil, has been reported to contribute to the prevention of cardiovascular disease. The present study describes an accurate and reproducible reversed-phase HPLC method to measure hydroxytyrosol in plasma. This compound was extracted from acidified plasma...

In chickens, we have shown that intestinal absorption of glucose via apical SGLT1 and basolateral GLUT2 transport systems is affected by dietary Na+; low-Na+ adapted birds show a dramatic reduction of glucose transporters in both membranes in the rectum, an intermediate response in the ileum and no effects in the jejunum. We have now studied the ef...

In chickens, we have shown that intestinal absorption of glucose via apical SGLT1 and basolateral GLUT2 transport systems is affected by dietary Na+; low-Na+ adapted birds show a dramatic reduction of glucose transporters in both membranes in the rectum, an intermediate response in the ileum and no effects in the jejunum. We have now studied the ef...

Na(+)-dependent D-glucose and D-galactose transport were studied in brush-border membrane vesicles (BBMVs) from kidney cortex isolated from both spontaneously hypertensive rats (SHR) and their normotensive genetic control Wistar-Kyoto (WKY) rats. Initial rates and accumulation ratios of Na(+)-dependent D-glucose and D-galactose transport were signi...

Transmural potential difference (PD), short-circuit current (Isc), and electrical resistance (R) were measured in the isolated mucosa of the duodenum, jejunum, ileum, proximal cecum, and rectum in order to characterize the electrical properties of the chicken small and large intestine. The chicken intestine was classified into three categories, reg...

trans-Resveratrol (trans-3,5,4'-trihydroxystilbene), a phenolic compound present in grapes, wines, and peanuts, has been reported to have health benefits including anticarcinogenic effects and protection against cardiovascular diseases. Despite its importance, little is known about its bioavailability in both humans and animals. A fundamental step...

We have studied the expression of Na+-D-glucose cotransporter in brush-border membrane vesicles (BBMVs) of chicken enterocytes to correlate the changes in the apical Na+-dependent transport with the changes in the amounts of transporter determined by Western blot analysis. Two different rabbit polyclonal antibodies were used simultaneously. The ant...

1. The effect of a low-NaCl diet (LS diet) on the properties of hexose transport across the brush-border and basolateral membranes of enterocytes from jejunum, ileum and rectum of the chicken was investigated. 2. In the brush-border membrane, LS adaptation had no effect on Km for alpha-methyl-D-glucoside while Vmax values were significantly reduced...

Development changes in alpha-methyl-D-glucoside and L-proline accumulation were studied using everted sleeves from the duodenum, jejunum, and ileum of chickens. Six age groups of chickens were used: 1 d and 1, 2, 3, 5 to 6, and 12 to 14 wk. Our results showed the presence of a Na+-dependent mechanism of sugar and amino acid uptake that is already f...

Regional brush-border uptakes of alpha-methyl-D-glucose and L-proline as well as morphometric parameters were studied from birth until adulthood in guinea pig small intestine. Intestinal weight, length, and area were fitted to two-segmented straight lines: from birth until the 2nd wk there was a sharp rise, whereas from day 14 to the adult stage th...

Na(+)-dependent D-glucose uptake was studied in jejunal brush-border membrane (BBM) vesicles of chickens at 2 days and 1, 2, 5-6, and 12-14 wk of age. Both initial rates and accumulation ratios of the Na(+)-dependent D-glucose transport were significantly higher during the 1st wk than at other ages. To explain the age-related changes observed in th...

1. We have studied L-valine transport by the caecal segments of 6- to 8-week-old chickens. Isolated enterocytes from the proximal caecum incubated with 0.1 mM L-valine can accumulate the substrate against a concentration gradient. After 50 min incubation, the intracellular L-valine concentration reached 0.53 mM, a value higher than that observed in...

The characteristics of the basolateral transport of D-glucose (D-Glc) and D-fructose (D-Fru) have been studied in membrane vesicles from the jejunum of 5- to 6-wk-old chickens. Uptake of hexoses was measured using a rapid filtration method. The maximal rate of transport (Vmax) for D-Glc was 2.36 nmol x mg(-1) x s(-1) and for D-Fru was 3.79 nmol x m...

The kinetic parameters of alpha-methyl-D-glucoside (alpha Glc1Me) have been determined in the small intestine in order to establish developmental and regional changes in the apical transport in embryos and newly hatched chicks. Results show that the apparent Michaelis constant (Km) values did not change during the period studied in each region of t...

The kinetic parameters of hexose uptake by the small and large intestine of the chicken have been determined in vitro. Rates of initial influx of alpha-methyl-D-glucoside and L-glucose were measured in everted sleeves of the duodenum, jejunum, ileum, proximal cecum, and rectum. Results show the following. 1) Maximal transport capacity values for al...

The absorptive surface of epithelial cells from chicken small and large intestine was studied at the day of hatch (1 d group) and at 2 and 6 wk after hatch. The segments considered were duodenum, jejunum, ileum, cecum (proximal, medial, and distal regions), and rectum. The length, diameter, and density of microvilli as well as cell apical diameter...

The properties of hexose transport across the apical and basolateral membranes of chicken enterocytes have been studied in the small and large intestine. Results show that (a) isolated epithelial cells from all segments except the coprodeum can accumulate 3-O-methylglucose (Glc3Me) against a concentration gradient, by a Na(+)-dependent and phloridi...

The proximal cecum of 5- and 13-wk-old chickens takes up L-proline (Pro) by two saturable pathways that differ in their requirement of Na+. The kinetic properties of Pro influx in cecal segments incubated in Na(+)-free conditions, have been studied and the effect of HgCl2 on the uptake process has been tested. Experiments were carried out using an...

A regional study of the intestinal hexose transport shows the role played by duodenum, jejunum and ileum during the chick perinatal development. From at least two days before hatching the three regions of small intestine accumulate alpha-Méthyl-D-Glucose (alpha-MG) by mediated transport mechanisms, and phloridzin inhibit about 90% of the uptakes. T...

1. The structure of the chicken caecal epithelium has been investigated at macroscopic and microscopic levels (scanning and transmission electron microscopy). 2. Morphological data distinguish three regions in the caecum: proximal, with well developed villi, but smaller and less numerous than those present at mid-jejunum; medial, with longitudinal...

We examined the characteristics of amino acid and sugar absorption by the proximal cecum (PC) of chickens during posthatch development. Rates of absorption of L-proline (Pro) and alpha-methyl-D-glucoside (MG) were measured at 2 days, 5 wk, and 13 wk after hatch with an in vitro everted-sleeve method. For each age, pieces of PC and midjejunum were i...

The effects of different experimental conditions on the in vitro transmural potential difference (PD) have been studied in the chicken rectum by the Ussing and Zerahn technique. Results have been analyzed with a statistical method to reveal the contribution of different controlled variables to the response, as well as the possible contribution of i...

Chickens have two well-developed ceca, with an epithelium that is histologically and functionally heterogeneous. The proximal region, close to the ileorectal junction, has well-developed villi and microvilli and is able to transport sugars and amino acids against a concentration gradient, by mechanisms virtually identical to those described for the...

1.1. The electrical parameters (PD and Isc) of the chicken rectum were studied in vitro, in birds fed either a high or a low NaCl diet.2.2. Chickens fed a high NaCl diet showed serosa negative values of PD and Isc(− 2.6 mV and − 39.2 μA/cm2, respectively), being unaffected by the suppression of Na+ in the incubation medium.3.3. Chickens fed a low N...