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

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

Circulating oestradiol determines liver lipid deposition in rats fed standard diets partially unbalanced with higher lipid or protein proportions.

The ingestion of excess lipids often produces the accumulation of liver fat. The modulation of diet energy partition affects this process and other metabolic responses, and oestrogens and androgens are implied in this process. Ten-week-old male and female rats were fed with either standard rat chow (SD), SD enriched with coconut oil (high-fat diet, HF), SD enriched with protein (high-protein diet, HP) or a 'cafeteria' diet (CAF) for 1 month. HF and CAF diets provided the same lipid-derived percentage of energy (40 %), HP diet protein energy derived was twice (40 %) that of the SD. Animals were killed under anaesthesia and samples of blood and liver were obtained. Hepatic lipid content showed sex-related differences: TAG accumulation tended to increase in HF and CAF fed males. Cholesterol content was higher only in the CAF males. Plasma oestradiol in HF and HP males was higher than in CAF. Circulating cholesterol was inversely correlated with plasma oestradiol. These changes agreed with the differences in the expression of some enzymes related to lipid and energy metabolism, such as fatty acid synthetase or phosphoglycolate phosphatase. Oestrogen protective effects extend to males with 'normal' diets, that is, not unbalanced by either lipid or protein, but this protection was not enough against the CAF diet. Oestradiol seems to actively modulate the liver core of 2C-3C partition of energy substrates, regulating cholesterol deposition and lactate production.

Modulation of Food Intake by Differential TAS2R Stimulation in Rat.

Metabolic surgery modulates the enterohormone profile, which leads, among other effects, to changes in food intake. Bitter taste receptors (TAS2Rs) have been identified in the gastrointestinal tract and specific stimulation of these has been linked to the control of ghrelin secretion. We hypothesize that optimal stimulation of TAS2Rs could help to modulate enteroendocrine secretions and thus regulate food intake. To determine this, we have assayed the response to specific agonists for hTAS2R5, hTAS2R14 and hTAS2R39 on enteroendocrine secretions from intestinal segments and food intake in rats. We found that hTAS2R5 agonists stimulate glucagon-like peptide 1 (GLP-1) and cholecystokinin (CCK), and reduce food intake. hTAS2R14 agonists induce GLP1, while hTASR39 agonists tend to increase peptide YY (PYY) but fail to reduce food intake. The effect of simultaneously activating several receptors is heterogeneous depending on the relative affinity of the agonists for each receptor. Although detailed mechanisms are not clear, bitter compounds can stimulate differentially enteroendocrine secretions that modulate food intake in rats.

Modulation of SHBG binding to testosterone and estradiol by sex and morbid obesity.

OBJECTIVE: Sex hormone-binding globulin (SHBG) binds and transports testosterone and estradiol in plasma. The possibility that SHBG is a mixture of transporting proteins has been postulated. We analyzed in parallel the effects of obesity status on the levels and binding capacity of circulating SHBG and their relationship with testosterone and estradiol. DESIGN: Anthropometric measures and plasma were obtained from apparently healthy young (i.e. 35 ± 7 years) premenopausal women (n = 32) and men (n = 30), with normal weight and obesity (BMI >30 kg/m2). METHODS: SHBG protein (Western blot), as well as the plasma levels of testosterone, estradiol, cortisol and insulin (ELISA) were measured. Specific binding of estradiol and testosterone to plasma SHBG was analyzed using tritium-labeled hormones. RESULTS: Significant differences in SHBG were observed within the obesity status and gender, with discordant patterns of change in testosterone and estradiol. In men, testosterone occupied most of the binding sites. Estrogen binding was much lower in all subjects. Lower SHBG of morbidly obese (BMI >40 kg/m2) subjects affected testosterone but not estradiol. The ratio of binding sites to SHBG protein levels was constant for testosterone, but not for estradiol. The influence of gender was maximal in morbid obesity, with men showing the highest binding/SHBG ratios. CONCLUSIONS: The results reported here are compatible with SHBG being a mixture of at least two functionally different hormone-binding globulins, being affected by obesity and gender and showing different structure, affinities for testosterone and estradiol and also different immunoreactivity.

Long-term increased carnitine palmitoyltransferase 1A expression in ventromedial hypotalamus causes hyperphagia and alters the hypothalamic lipidomic profile.

Lipid metabolism in the ventromedial hypothalamus (VMH) has emerged as a crucial pathway in the regulation of feeding and energy homeostasis. Carnitine palmitoyltransferase (CPT) 1A is the rate-limiting enzyme in mitochondrial fatty acid ß-oxidation and it has been proposed as a crucial mediator of fasting and ghrelin orexigenic signalling. However, the relationship between changes in CPT1A activity and the intracellular downstream effectors in the VMH that contribute to appetite modulation is not fully understood. To this end, we examined the effect of long-term expression of a permanently activated CPT1A isoform by using an adeno-associated viral vector injected into the VMH of rats. Peripherally, this procedure provoked hyperghrelinemia and hyperphagia, which led to overweight, hyperglycemia and insulin resistance. In the mediobasal hypothalamus (MBH), long-term CPT1AM expression in the VMH did not modify acyl-CoA or malonyl-CoA levels. However, it altered the MBH lipidomic profile since ceramides and sphingolipids increased and phospholipids decreased. Furthermore, we detected increased vesicular γ-aminobutyric acid transporter (VGAT) and reduced vesicular glutamate transporter 2 (VGLUT2) expressions, both transporters involved in this orexigenic signal. Taken together, these observations indicate that CPT1A contributes to the regulation of feeding by modulating the expression of neurotransmitter transporters and lipid components that influence the orexigenic pathways in VMH.

Oleoyl-estrone.

Oleoyl-estrone (OE) is a powerful slimming agent that is also present in plasma and adipose tissue, where it is synthesized. It acts through the formation of a derivative W. OE effects (and W levels) are proportional to the dose. OE reduces food intake but maintains energy expenditure (thermogenesis). The energy gap is fulfilled with adipose tissue fat, sparing body protein and maintaining glycemia (and glycogen) with lower insulin and leptin levels. OE (in fact W) acts through specific receptors, different from those of estrogen. OE increases cholesterol catabolism, reducing hypercholesterolemia in obese rats. The main metabolic effect on adipose tissue is lowering of lipid synthesis, maintaining unchanged the intracellular lipolytic processes; the imbalance favors the progressive loss of fat, which is largely used by the muscle. OE administration induces additive effects with other antiobesity agents, such as ß(3)-adrenergic agonists, forcing a massive loss of lipid. Corticosteroids markedly limit OE action by altering the liver control of lipogenesis. OE also inhibits the action of 17ß-hydroxysteroid dehydrogenase, decreasing the synthesis of ß-estradiol and testosterone. Discontinuous treatment allows for maximal efficacy both in rats and humans. OE has the advantage that the loss of fat is maintained and does not require additional dietary limitations.

Oleoyl-estrone is a precursor of an estrone-derived ponderostat signal.

Oleoyl-estrone (OE) is a powerful anti-obesity compound that decreases food intake, decreases insulin resistance and circulating cholesterol. OE stimulates a severe loss of body fat by decreasing adipose tissue lipid synthesis and maintaining lipolysis. Therefore, the body economy loses lipid energy because energy expenditure is maintained. This study analyses the discrepancy between OE effects and the distribution of labelled OE in plasma. Estrone radioimmunoassay of organic solvent plasma extracts of rats treated with OE showed the massive presence of acyl-estrone, but saponification did not release estrone, but containing similar unknown compound. Analysis of label distribution in plasma after oral gavages of (3)H-OE showed the presence of a more hydrophilic compound than OE or any estrogen as well as (3)H(2)O, formed from (3)H-OE in the acidic stomach medium. OE was not attached to a specific transporter in plasma. Through serum HPLC analysis we found W, a labelled derivative more hydrophilic than OE or estrone. The results were confirmed using (14)C-OE. HPLC-MS/MS studies showed that plasma OE levels were one order of magnitude lower than those of W. When liver cell cytosols from rats laden with (3)H-OE were incubated with nuclei from untreated rats, the OE-derived label (i.e., Ws) was found attached to nuclear DNA. Neither estradiol nor estrone interfered with its binding. W is a fairly hydrophilic compound of low molecular weight containing the estrone nucleus, but it is not an ester because saponification or esterases do not yield estrone as OE does. It is concluded that OE acts through its conversion to W, its active form; which binds to a nuclear receptor different from that of estrogen. The estimated W serum levels are proportional to the pharmacological OE effects in vivo. We postulate W as a new type of hormone that exerts the full range of in vivo effects thus far attributed to OE. The full identification of W is anticipated to open the way for the development of new OE-like anti-obesity drugs.

Maternal treatment with oleoyl-estrone induces resistance to lipid accrual in their descendants.

OBJECTIVE: To determine whether treatment of rat dams with oleoyl-estrone (OE) has an effect on the offspring's long-term response to diet restriction during lactation. METHODS AND PROCEDURES: Control, OE-treated, and diet-restricted dams were treated up to day 15 of lactation. Changes in food intake and body weight were recorded for dams and their pups. After weaning, pups received a 4-week standard diet followed by a 4-week period of high-fat diet. Lipid, protein, and energy content of pups plus energy intake and efficiency. Serum metabolites (glucose, urea, and cholesterol) and serum hormones (adiponectin, leptin, insulin, and sexual hormones). RESULTS: Neither pups from dams in the OE-treated nor in the diet-restricted group showed significant changes in weight, though these two groups ingested 79% of food ingested by controls. At weaning, the pups from OE-treated rats were smaller than those of the control or diet-restricted groups. These pups maintained the differences in size and lipid content during the 4-week standard-diet period, whereas pups from diet-restricted dams showed a sharp decrease in their lipid content. During the 4 weeks of high-fat diet, the male offspring from OE-treated dams increased the difference in lipid content in relation to the pups from control dams whereas in females the differences decreased. Female offspring from diet-restricted dams showed the most marked changes in metabolite and hormone levels in relation to controls. DISCUSSION: Treatment of lactating dams with OE programs the metabolic response of their offspring to resist the challenge of a high-fat diet that would lead to obesity in adulthood.

Treatment of pregnant rats with oleoyl-estrone slows down pup fat deposition after weaning.

BACKGROUND: In rats, oral oleoyl-estrone (OE) decreases food intake and body lipid content. The aim of this study was to determine whether OE treatment affects the energy metabolism of pregnant rats and eventually, of their pups; i.e. changes in normal growth patterns and the onset of obesity after weaning. METHODS: Pregnant Wistar rats were treated with daily intragastric gavages of OE in 0.2 ml sunflower oil from days 11 to 21 of pregnancy (i.e. 10 nmol oleoyl-estrone/g/day). Control animals received only the vehicle. Plasma and hormone metabolites were determined together with variations in cellularity of adipose tissue. RESULTS: Treatment decreased food intake and lowered weight gain during late pregnancy, mainly because of reduced adipose tissue accumulation in different sites. OE-treated pregnant rats' metabolic pattern after delivery was similar to that of controls. Neonates from OE-treated rats weighed the same as those from controls. They also maintained the same growth rate up to weaning, but pups from OE-treated rats slowed their growth rate afterwards, despite only limited differences in metabolite concentrations. CONCLUSION: The OE influences on pup growth can be partially buffered by maternal lipid mobilization during the second half of pregnancy. This maternal metabolic "imprinting" may condition the eventual accumulation of adipose tissue after weaning, and its effects can affect the regulation of body weight up to adulthood.

Short-term oleoyl-estrone treatment affects capacity to manage lipids in rat adipose tissue.

BACKGROUND: Short-term OE (oleoyl-estrone) treatment causes significant decreases in rat weight mainly due to adipose tissue loss. The aim of this work was to determine if OE treatment affects the expression of genes that regulate lipid metabolism in white adipose tissue. RESULTS: Gene expression in adipose tissue from female treated rats (48 hours) was analysed by hybridization to cDNA arrays and levels of specific mRNAs were determined by real-time PCR. Treatment with OE decreased the expression of 232 genes and up-regulated 75 other genes in mesenteric white adipose tissue. The use of real-time PCR validate that, in mesenteric white adipose tissue, mRNA levels for Lipoprotein Lipase (LPL) were decreased by 52%, those of Fatty Acid Synthase (FAS) by 95%, those of Hormone Sensible Lipase (HSL) by 32%, those of Acetyl CoA Carboxylase (ACC) by 92%, those of Carnitine Palmitoyltransferase 1b (CPT1b) by 45%, and those of Fatty Acid Transport Protein 1 (FATP1) and Adipocyte Fatty Acid Binding Protein (FABP4) by 52% and 49%, respectively. Conversely, Tumour Necrosis Factor (TNFalpha) values showed overexpression (198%). CONCLUSION: Short-term treatment with OE affects adipose tissue capacity to extract fatty acids from lipoproteins and to deal with fatty acid transport and metabolism.

Oleoyl-estrone treatment to late pregnant and mid-lactating rats affects the expression of lipid metabolism genes.

The purpose of this study was to determine whether OE treatment affects the expression of genes related to lipid metabolism under two physiological conditions: late pregnancy and mid-lactation, both characterized by lipid mobilization. Samples of periovarian and retroperitoneal adipose tissue from 21-day pregnant or 15-day lactating dams were used. The expression of LPL, FATP1, FABP4, HSL, ACC1, FAS, PEPCK, GLUT4, PDK4, SREBP1c, adiponutrin and leptin, were compared with their expression in virgin rats. In pregnant rats, FABP4, HSL, PEPCK and PDK4 were over expressed in the periovarian site compared to virgin rats, whereas adiponutrin, FAS, GLUT4 and SREBP1c were underexpressed; the retroperitoneal fat depot showed a similar pattern but ACC1 and leptin were also underexpressed. OE treatment caused a generalized decrease in gene expression in both adipose depots. In lactating dams, the gene expression profile at the periovarian depot was similar to that observed in pregnant rats. OE treatment mimicked the trend observed in pregnant rats, although the intensity of the gene expression changes was lower. After OE treatment, the retroperitoneal adipose depot showed a completely different pattern since the values were close to those of virgin rats. These results corroborate that OE effects in adipose tissue, lowering lipids and depressing their metabolism, already described under other physiological situations, can be also found in late pregnancy and lactation.

Oleoyl-estrone treatment activates apoptotic mechanisms in white adipose tissue.

To determine whether lipid mobilization in white adipose tissue caused by oleoyl-estrone (OE) treatment leads to activation of apoptosis, female Wistar rats were given a daily oral gavage of 10 micromol/kg of OE in 0.2 ml of sunflower oil and DNA fragmentation in different adipose tissues was assessed by ligation-mediated PCR after 6, 24, 48, or 240 h. Expression of selected apoptotic target genes was analysed by RT-PCR in adipose tissue from animals treated for 2 days. The response of adipose tissue to OE treatment was not the same in all locations. In mesenteric adipose tissue, a significant increase in the expression of Bid, Bax, caspase 3 and caspase 8 was detected, whereas in periovaric adipose tissue, only Bax and caspase 3 expression showed significant increases. No effect was detected in subcutaneous or retroperitoneal adipose tissue. The increased expression of apoptotic factors suggests that this pathway could be activated by OE treatment.

Rats treated with oleoyl-oestrone maintain glucidic homeostasis: comparisons with a pair-fed model.

To determine whether or not the weight (and fat) loss induced by oleoyl-oestrone treatment results only as a consequence of decreased food intake, we compared treated animals with a pair-fed model. To this end, Wistar female rats received daily oral gavages of 10 mumol/kg per d oleoyl-oestrone in sunflower oil, or vehicle alone for 10 or 20 d. A second group of rats received the gavage of sunflower oil and the same amount of food ingested as the oleoyl-oestrone-treated animals (pair-fed group). Rats treated with oleoyl-oestrone maintained glucidic metabolism homeostasis despite a marked decrease in adipose tissue weight (P<0.001). Pair-fed rats exhibited a different pattern, comparable to short-term starvation, with greatly decreased glycogen stores (P<0.0001). The most significant effects were detected in the 10 d period groups. Oleoyl-oestrone affected the activity of the ponderostat system not only by decreasing appetite but also by modifying energy partition: treated animals maintained their glucose and energy homeostasis despite decreased food intake and the massive depletion of lipid stores.

Effects of oral estrone on rat energy balance.

Oral doses of estrone from 10 nmol/(kg day) to 10 micromol/(kg day) were given to adult Wistar male rats for 10 days. Body composition, energy balance, total body estrone balance and plasma metabolites and hormones were measured at the end of the treatment. Body weight (as well as food intake, body energy, fat and water accrual) increased at doses in the 10--100 nmol/(kg day) range, but decreased at higher doses. Energy expenditure decreased with increasing doses of estrone. Plasma metabolite changes suggested the maintenance of energy homeostasis, and lipid parameters indicated that lipid mobilization increased with the increasing doses of estrone. Plasma estrone, acyl-estrone and estradiol levels decreased at low doses and increased at high doses of estrone. We conclude that: (a) repeated estrone gavages, even at very high doses, do not result in the accrual of estrone in the body; (b) low doses of estrone promote growth and high doses decrease body mass and fat accretion; (c) administration of estrone at low doses decreases its circulating levels and the levels of estradiol and acyl-estrone, a situation reverted at higher doses and (d) estrone administration induces a dose-dependent shift towards lower energy expenditure.

Effects of oleoyl-estrone with dexfenfluramine, sibutramine or phentermine on overweight rats.

We studied the combination of oleoyl-estrone with either dexfenfluramine, sibutramine or phentermine in overweight male rats treated for 10 days in order to determine whether they shared a mechanism of action. Oleoyl-estrone, dexfenfluramine and sibutramine decreased body weight and energy (essentially lipids); losses were higher when combined with oleoyl-estrone. Glycemia was maintained except under phentermine; oleoyl-estrone induced decreases in triacylglycerols, cholesterol, insulin and HOMA (homeostasis model assessment). Combination of oleoyl-estrone and sibutramine resulted in the loss of up to 29% body energy in 10 days. Energy expenditure was maintained. The effects of oleoyl-estrone and dexfenfluramine or sibutramine on appetite were substantially additive. All oleoyl-estrone-treated rats showed increased insulin sensitivity. In conclusion, combined treatment of overweight rats with oleoyl-estrone and sibutramine or dexfenfluramine results in a dramatic loss of weight and fat, whilst maintaining circulating energy homoeostasis.

Tamoxifen does not prevent the mobilization of body lipids elicited by oleoyl-estrone.

Oleoyl-estrone is a powerful, slimming adipose tissue-derived signal that has biological effects widely opposed to those of its estrone moiety. The present experiment was designed to determine whether oleoyl-estrone effects on body energy are mediated by the estrogen receptor, blocked with the antagonist tamoxifen. Male Wistar rats were given daily oral doses of 10 micromol/kg d of oleoyl-estrone in oil containing 0 or 0.40 mg/kg d of tamoxifen. The data were compared with controls receiving only oil or 50 nmol/kg d of free estrone. After 10 days, the rats were killed, and their body composition and plasma metabolites and hormones were analyzed. Rats receiving estrone increased their body energy and lipid content compared with controls. Both groups of oleoyl-estrone-treated rats lost body weight, energy, and lipid; the losses in the rats receiving tamoxifen alone were less marked than in those receiving oleoyl-estrone. No significant changes in plasma glucose or triacylglycerols were observed. The patterns of change of estrone sulphate, estradiol, and oleoyl-estrone were consistent with a noticeable hydrolysis of oleoyl-estrone. The lack of differences in the fat mass in oleoyl-estrone-treated rats irrespective of the presence of tamoxifen suggested that the estrogenic pathway was not responsible for the slimming effects observed. Thus, it can be concluded that oleoyl-estrone effects are not mediated through its conversion to estrone or estradiol acting through the estrogen receptor. Tamoxifen partly mimicked the slimming effects of oleoyl-estrone; this could be speculatively explained by tamoxifen acting through the oleoyl-estrone signalling pathway.

[Weight loss in a patient with morbid obesity under treatment with oleoyl-estrone]. / Pérdida de peso en un paciente con obesidad mórbida en tratamiento con oleoil-estrona.

BACKGROUND AND OBJECTIVE: Oleoyl-estrone administration in rats results in loss of body fat and sparing protein via decreasing food intake and maintaining energy expenditure. Oleoyl-estrone also decreases insulin resistance and hyperlipidemia and has no direct estrogenic effects. Our objective was to determine whether oral oleoyl-estrone was effective in the treatment of morbid obesity in a voluntary patient. PATIENT AND METHOD: Oleoyl-estrone (150-300 mol/d) was given to a morbid obese man (BMI: 51.9) over 10 consecutive 21-day trial periods of oral drug intake followed by at least two months of recovery. This treatment was given without additional dietary restrictions. Plasma metabolites, hormones and enzymes were measured before treatment, during active administration and at recovery periods. RESULTS: Oleoyl-estrone decreased the body weight (38.5 kg in 27 months, final BMI: 40.5). No rebound trends were observed. No significant changes in blood parameters, plasma metabolites, hormones or enzymes were observed as a consequence of the treatment. CONCLUSIONS: Oleoyl-estrone decreased body weight in this subject without affecting metabolites or hormones, similarly to its effects in animal models. This means that oleoyl-estrone could have a marked potential as an anti-obesity drug.