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1.
Article in English | MEDLINE | ID: mdl-34534676

ABSTRACT

Amylin is a 37-amino acid polypeptide that has been found to be involved in feeding regulation in some mammals, birds, and goldfish. We cloned amylin of Siberian sturgeon and detected its distribution pattern in 15 tissues. The expression levels in the periprandial period (pre-and post-feeding), the changes in the food intake, and the expression levels of related appetite factors after the intraperitoneal injection of amylin were detected. The expression of amylin was found to be the highest in the hypothalamus. Compared with 1 h pre-feeding, the expression levels of amylin in the hypothalamus and duodenum were increased significantly 1 h post-feeding. Compared with the control group (saline), intraperitoneal injection of 50 ng/g, 100 ng/g, and 200 ng/g of amylin significantly inhibited food intake at 1 h post injection, but not at 3 h and 6 h. The injection of 50 ng/g, 100 ng/g, and 200 ng/g amylin significantly inhibited the cumulative feed. After 1 h of 50 ng/g amylin injection, the levels of MC4R and somatostatin in the hypothalamus increased significantly, while the levels of amylin and NPY decreased significantly. The levels of CCK in the valvular intestine were increased significantly. Insulin in the duodenum was also increased significantly, but there was no significant change in ghrelin in the duodenum. These results show that amylin inhibits feeding in Siberian sturgeon by down-regulating the appetite-stimulating factor NPY and up-regulating the appetite-suppressing factors somatostatin, MC4R, CCK, and insulin. This study provides a theoretical basis for studying the feeding function and action mechanisms of amylin in Siberian sturgeon.


Subject(s)
Fish Proteins/metabolism , Fishes/metabolism , Islet Amyloid Polypeptide/metabolism , Amino Acid Sequence , Animals , Appetite Depressants/administration & dosage , Appetite Depressants/metabolism , Appetite Regulation/drug effects , Appetite Regulation/genetics , Appetite Regulation/physiology , Base Sequence , Cloning, Molecular , Duodenum/metabolism , Eating/drug effects , Eating/genetics , Eating/physiology , Feeding Behavior/drug effects , Feeding Behavior/physiology , Fish Proteins/administration & dosage , Fish Proteins/genetics , Fishes/genetics , Fishes/physiology , Gene Expression/drug effects , Hypothalamus/metabolism , Injections, Intraperitoneal , Islet Amyloid Polypeptide/administration & dosage , Islet Amyloid Polypeptide/genetics , Phylogeny , Sequence Homology, Amino Acid , Tissue Distribution
2.
Am J Physiol Regul Integr Comp Physiol ; 319(6): R673-R683, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33026822

ABSTRACT

Oxytocin (OT) is a neuropeptide whose central receptor-mediated actions include reducing food intake. One mechanism of its behavioral action is the amplification of the feeding inhibitory effects of gastrointestinal (GI) satiation signals processed by hindbrain neurons. OT treatment also reduces carbohydrate intake in humans and rodents, and correspondingly, deficits in central OT receptor (OT-R) signaling increase sucrose self-administration. This suggests that additional processes contribute to central OT effects on feeding. This study investigated the hypothesis that central OT reduces food intake by decreasing food seeking and food motivation. As central OT-Rs are expressed widely, a related focus was to assess the role of one or more OT-R-expressing nuclei in food motivation and food-seeking behavior. OT was delivered to the lateral ventricle (LV), nucleus tractus solitarius (NTS), or ventral tegmental area (VTA), and a progressive ratio (PR) schedule of operant reinforcement and an operant reinstatement paradigm were used to measure motivated feeding behavior and food-seeking behavior, respectively. OT delivered to the LV, NTS, or VTA reduced 1) motivation to work for food and 2) reinstatement of food-seeking behavior. Results provide a novel and additional interpretation for central OT-driven food intake inhibition to include the reduction of food motivation and food seeking.


Subject(s)
Appetite Depressants/administration & dosage , Appetite Regulation/drug effects , Eating/drug effects , Feeding Behavior/drug effects , Lateral Ventricles/drug effects , Motivation/drug effects , Oxytocin/administration & dosage , Solitary Nucleus/drug effects , Ventral Tegmental Area/drug effects , Animals , Infusions, Intraventricular , Lateral Ventricles/physiology , Male , Rats, Sprague-Dawley , Solitary Nucleus/physiology , Ventral Tegmental Area/physiology
3.
Am J Public Health ; 110(1): 109-111, 2020 01.
Article in English | MEDLINE | ID: mdl-31751147

ABSTRACT

Objectives. To investigate the prospective association of diet pill and laxative use for weight control with subsequent first eating disorder diagnosis in young women.Methods. We used longitudinal data from 10 058 US women spanning 2001 through 2016. We used multivariable logistic regression models, adjusting for age, race/ethnicity, and overweight status to estimate the association between weight-control behaviors and subsequent eating disorder diagnosis.Results. Among those who had not previously received an eating disorder diagnosis, women who reported diet pill (adjusted odds ratio [AOR] = 5.6; 95% confidence interval [CI] = 3.0, 10.5) or laxative (AOR = 6.0; 95% CI = 4.2, 8.7) use for weight control had higher odds of receiving a subsequent first eating disorder diagnosis within 1 to 3 years than those who did not report using these products.Conclusions. Use of diet pills or laxatives for weight loss can be dangerous and may be a warning sign that warrants counseling and evaluation for the presence of or risk of developing an eating disorder.Public Health Implications. Policymakers and public health professionals should develop and evaluate policy initiatives to reduce or prohibit access to diet pills and laxatives abused for weight control.


Subject(s)
Appetite Depressants/administration & dosage , Feeding and Eating Disorders/epidemiology , Laxatives/administration & dosage , Weight Loss , Adolescent , Adult , Drug Utilization , Feeding Behavior , Feeding and Eating Disorders/diagnosis , Female , Humans , Logistic Models , Longitudinal Studies , Odds Ratio , Prospective Studies , United States/epidemiology , Young Adult
4.
Am J Physiol Regul Integr Comp Physiol ; 314(4): R533-R539, 2018 04 01.
Article in English | MEDLINE | ID: mdl-29351428

ABSTRACT

Although central melanocortin 4 receptor (MC4R) blockade abolishes the central nervous system (CNS)-mediated anorexogenic, antidiabetic, and cardiovascular actions of leptin, chronic MC4R stimulation fails to completely mimic the effects of leptin. Because neuropeptide Y (NPY) and MC4R exert opposite effects on cardiovascular and metabolic functions, we tested the role of NPY in offsetting the long-term actions of MC4R activation. Wild-type (WT) and NPY-deficient (NPY-/-) mice were implanted with telemetry probes for measuring mean arterial pressure (MAP) and heart rate (HR) 24 h/day. After the mice recovered from surgery and stable baseline measurements, the MC3/4R agonist melanotan II (MTII, 120 µg·kg-1·day-1 iv) was infused for 7 days followed by a recovery period. No major differences between groups were observed at baseline except for slightly higher food intake and HR in NPY-/- mice (4.3 ± 0.2 vs. 3.4 ± 0.2 g/day and 567 ± 14 vs. 522 ± 13 beats/min). Chronic MTII infusion reduced food intake in both groups while causing transient increases in MAP and HR only in WT mice (peaks of 11 ± 3 mmHg and 126 ± 13 beats/min). To examine whether NPY deficiency would amplify the antidiabetic effects of MC4R activation, diabetes was induced with streptozotocin (STZ) 1 wk before baseline measurements were taken, and the same experimental protocol was followed. In WT and NPY-/- mice, STZ-induced diabetes led to similar hyperphagia, hyperglycemia, and weight loss, which were not reversed by chronic MTII treatment. Our results demonstrate that chronic MC4R activation, even in NPY-deficient mice, does not mimic chronic antidiabetic, cardiovascular, or metabolic actions of leptin, and that NPY is not essential for hyperphagia or cardiovascular changes associated with diabetes.


Subject(s)
Appetite Depressants/administration & dosage , Appetite Regulation/drug effects , Arterial Pressure/drug effects , Behavior, Animal/drug effects , Blood Glucose/drug effects , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/administration & dosage , Neuropeptide Y/deficiency , Peptides, Cyclic/administration & dosage , Receptor, Melanocortin, Type 4/agonists , alpha-MSH/analogs & derivatives , Animals , Biomarkers/blood , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Experimental/psychology , Heart Rate/drug effects , Infusions, Intravenous , Insulin/blood , Leptin/blood , Male , Mice, Knockout , Neuropeptide Y/genetics , Receptor, Melanocortin, Type 4/metabolism , Signal Transduction/drug effects , alpha-MSH/administration & dosage
5.
Diabetes Obes Metab ; 20(8): 1836-1851, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29938884

ABSTRACT

AIM: We performed acute and chronic studies in healthy and diet-induced obese animals using mouse-specific or monkey-specific dual GLP-1R/GCGR agonists to investigate their effects on food intake, body weight, blood glucose control and insulin secretion. The selective GLP-1R agonist liraglutide was used as comparator. METHODS: The mouse-specific dual agonist and liraglutide were tested in lean wild type, GLP-1R knockout and diet-induced obese mice at different doses. A chronic study was performed in DIO mice to investigate the effect on body weight, food consumption and total energy expenditure (TEE) in obese and diabetic monkeys with a focus on body weight and energy intake. RESULTS: The mouse-specific dual agonist and liraglutide similarly affected glycaemic control. A higher loss in body weight was measured in dual agonist-treated obese mice. The dual agonist significantly enhanced plasma glucose excursion in overnight fed GLP-1R-/- mice, probably reflecting a potent GCGR agonist activity. It increased TEE and enhanced fat and carbohydrate oxidation, while liraglutide produced no effect on TEE. In obese and diabetic monkeys, treatment with the monkey-specific dual agonist reduced total energy intake to 60%-70% of baseline TEI during chronic treatment. A decrease in body weight and significant improvement in glucose tolerance was observed. CONCLUSIONS: In DIO mice and non-human primates, dual agonists elicited robust glycaemic control, similar to the marketed GLP-1R agonist, while eliciting greater effects on body weight. Results from DIO mice suggest that the increase in TEE is caused not only by increased fat oxidation but also by an increase in carbohydrate oxidation.


Subject(s)
Appetite Depressants/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Glucagon-Like Peptide-1 Receptor/agonists , Hyperglycemia/prevention & control , Hypoglycemic Agents/therapeutic use , Obesity/drug therapy , Receptors, Glucagon/agonists , Animals , Animals, Outbred Strains , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Body Weight/drug effects , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Diet, High-Fat/adverse effects , Dose-Response Relationship, Drug , Drug Therapy, Combination/adverse effects , Energy Intake/drug effects , Energy Metabolism/drug effects , Female , Glucagon-Like Peptide-1 Receptor/genetics , Glucagon-Like Peptide-1 Receptor/metabolism , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/adverse effects , Insulin Secretion/drug effects , Macaca fascicularis , Male , Mice, Inbred C57BL , Mice, Knockout , Obesity/blood , Obesity/etiology , Obesity/metabolism , Random Allocation , Receptors, Glucagon/metabolism
6.
Eur J Nutr ; 57(2): 585-592, 2018 Mar.
Article in English | MEDLINE | ID: mdl-27832366

ABSTRACT

PURPOSE: Protein consumption after resistance exercise potentiates muscle protein synthesis, but its effects on subsequent appetite in this context are unknown. This study examined appetite and energy intake following consumption of protein- and carbohydrate-containing drinks after resistance exercise. METHODS: After familiarisation, 15 resistance training males (age 21 ± 1 years, body mass 78.0 ± 11.9 kg, stature 1.78 ± 0.07 m) completed two randomised, double-blind trials, consisting of lower-body resistance exercise, followed by consumption of a whey protein (PRO 23.9 ± 3.6 g protein) or dextrose (CHO 26.5 ± 3.8 g carbohydrate) drink in the 5 min post-exercise. An ad libitum meal was served 60 min later, with subjective appetite measured throughout. Drinks were flavoured and matched for energy content and volume. The PRO drink provided 0.3 g/kg body mass protein. RESULTS: Ad libitum energy intake (PRO 3742 ± 994 kJ; CHO 4172 ± 1132 kJ; P = 0.007) and mean eating rate (PRO 339 ± 102 kJ/min; CHO 405 ± 154 kJ/min; P = 0.009) were lower during PRO. The change in eating rate was associated with the change in energy intake (R = 0.661, P = 0.007). No interaction effects were observed for subjective measures of appetite. The PRO drink was perceived as creamier and thicker, and less pleasant, sweet and refreshing (P < 0.05). CONCLUSION: These results suggest whey protein consumption after resistance exercise reduces subsequent energy intake, and this might be partially mediated by a reduced eating rate. Whilst this reduced energy intake is unlikely to impair hypertrophy, it may be of value in supporting an energy deficit for weight loss.


Subject(s)
Appetite Depressants/administration & dosage , Appetite Regulation , Energy Drinks , Energy Intake , Resistance Training , Sports Nutritional Physiological Phenomena , Whey Proteins/administration & dosage , Adult , Appetite Depressants/therapeutic use , Beverages , Dietary Carbohydrates/administration & dosage , Double-Blind Method , Feeding Behavior , Food Preferences , Glucose/administration & dosage , Humans , Male , Reproducibility of Results , Snacks , Time Factors , Young Adult
7.
Eur J Nutr ; 57(2): 607-615, 2018 Mar.
Article in English | MEDLINE | ID: mdl-27885554

ABSTRACT

INTRODUCTION: Different studies have assessed the influence of chewing gum to aid control of appetite and reduce food intake. PURPOSE: The aims of the present study were to evaluate the effects of chewing gum on satiety, food hedonics and snack intake and to explore the potential effects of the combination of Garcinia c ambogia, green coffee extract and L-carnitine on satiety, when administered in a gum format. METHODS: This was a prospective study in which 57 subjects randomly received three kinds of treatments, in a crossover design: (1) active gum; (2) placebo gum; and (3) no gum. Food preferences and appetite sensations were evaluated by means of the Leeds Food Preference Questionnaire and visual analog scales. RESULTS: There was a significant reduction in low-fat sweet snack intake with placebo gum and the active gum compared to no gum and a reduction in high-fat sweet snack intake with the active gum compared to placebo gum and no gum. Total caloric intake was only reduced in the active gum condition. Both the active and placebo gum conditions significantly reduced hunger and prospective food consumption and increased fullness compared to no gum and were associated with a reduced wanting for sweet food in the LFPQ, consistent in a reduction in the relative preference for sweet snacks versus savoury snacks. CONCLUSION: This study supports the notion that chewing gum containing nutraceutical products might aid in the control over snack intake and reduce hunger sensations.


Subject(s)
Appetite Regulation , Carnitine/therapeutic use , Chewing Gum , Coffea/chemistry , Garcinia/chemistry , Overweight/diet therapy , Plant Extracts/therapeutic use , Adult , Appetite Depressants/administration & dosage , Appetite Depressants/therapeutic use , Argentina , Body Mass Index , Carnitine/administration & dosage , Cross-Over Studies , Diet, Reducing , Double-Blind Method , Female , Food Preferences , Humans , Male , Overweight/prevention & control , Patient Compliance , Plant Extracts/administration & dosage , Satiety Response , Seeds/chemistry , Snacks
8.
Nutr Neurosci ; 21(8): 546-555, 2018 Oct.
Article in English | MEDLINE | ID: mdl-28511588

ABSTRACT

STUDY OBJECTIVES: Sleep is important for memory consolidation in children. This study intended to find out whether an evening milk-based drink could influence sleep efficiency and memory recall in a group of Indonesian children (5-6 years old) with sleep deprivation. METHODS: Children were randomly allocated to one of three interventions: Reference product, satiety-stimulating product, and a relaxing product. The intervention lasted for 6 weeks and children consumed two servings per day of each 200 ml, the serving in the morning being the same for all children. All measurements took place at baseline and at the end of the intervention. Sleep parameters were studied using actigraphy and a sleep diary during three consecutive days. Memory consolidation was tested using a 20 word-pair list, which was memorized the evening before being recalled the next morning at home-base. Anthropometry was measured using standard equipment. RESULTS: The Satiety group showed a significant decrease in word recall, and a significant increase in nocturnal awakenings that was inversely associated with sleep efficiency at the end of the intervention. Sleep efficiency did not differ between the three groups being 75.5 ± 8.6% and 75.7 ± 6.3% at baseline and end of the intervention, respectively. Despite the lower energy intake in the Standard (reference) group, this condition showed the highest increase in weight. DISCUSSION: Evening growing-up milks can affect memory recall, sleep characteristics, and growth. However, to correct sleep efficiency and sleep duration, improvement of parental behavior may be the most important factor with nutrition providing a supplementary effect.


Subject(s)
Child Nutritional Physiological Phenomena , Dietary Supplements , Hypnotics and Sedatives/therapeutic use , Milk , Sleep Disorders, Intrinsic/therapy , Actigraphy , Animals , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Child , Child, Preschool , Dietary Supplements/adverse effects , Double-Blind Method , Female , Humans , Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/adverse effects , Indonesia , Male , Memory Consolidation , Memory Disorders/etiology , Memory Disorders/prevention & control , Mental Recall , Milk/adverse effects , Severity of Illness Index , Sleep Deprivation/etiology , Sleep Deprivation/prevention & control , Sleep Disorders, Intrinsic/physiopathology , Snacks , Weight Gain
9.
Appetite ; 130: 104-109, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30081055

ABSTRACT

Although the neuropeptide oxytocin exhibits many of the characteristics that would support its use as an anorectic agent for overeaters, studies of oxytocin's effectiveness at reducing eating in humans remain limited. In a double-blind, placebo-controlled crossover study, under the pretext of examining oxytocin's effects on various aspects of sensory perception, 20 men were given 24 IU of oxytocin and took a taste test of sweet, salty, and neutral snacks 45 min later. Participants self-rated appetite, anxiety, and other mood parameters, and then were left alone for 10 min with the pre-weighed snack food and invited to help themselves. To minimize the influence of hunger-driven eating, lunch had been provided immediately after oxytocin administration. In line with Ott et al. (2013), oxytocin significantly reduced the consumption of sweet foods; however, it also reduced consumption of salty snacks. Self-reported anxiety did not differ across drug conditions. The study is the first to demonstrate an effect of oxytocin on snack eating at 45 min post administration and on salty snacks. The anorectic efficacy of oxytocin after 45 min cannot easily be explained by the same mechanism as the one presumed to underpin its effects in previous studies that adopted much longer intervals between drug administration and testing.


Subject(s)
Appetite Depressants/pharmacology , Appetite/drug effects , Oxytocin/pharmacology , Administration, Intranasal , Adolescent , Adult , Appetite Depressants/administration & dosage , Cross-Over Studies , Double-Blind Method , Energy Intake/drug effects , Humans , Male , Oxytocin/administration & dosage , Snacks , Taste , Young Adult
10.
Drug Dev Res ; 79(5): 225-233, 2018 08.
Article in English | MEDLINE | ID: mdl-30188585

ABSTRACT

Preclinical Research & Development Current drugs for obesity treatment have limited efficacy and considerable adverse effects. Combination of drugs with complementary mechanisms of action at lower doses may produce a greater efficacy with a better safety profile. This study was designed to assess the anorectic effect and safety of a diethylpropion + topiramate mixture in rats. The anorectic effect of drugs was measured using a sweetened milk consumption model, and the corresponding interaction was determined by isobolographic analysis, interaction index and confidence intervals. Additionally, blood pressure was measured using a sphygmomanometer in the rat tail. Diethylpropion and topiramate alone or in combination increased the anorectic effect in a dose-dependent fashion in either nondeprived or 12 hr food-deprived rats. All theoretical ED30 values of diethylpropion + topiramate combinations at 1:1, 1:3, and 3:1 dose ratios were significantly higher than experimental ED30 values. In addition, interaction indices and confidence intervals confirmed the potentiation between both drugs. Theoretical ED30 of diethylpropion + topiramate combination did not affect the blood pressure. Data suggests that low doses of the diethylpropion + topiramate combination can potentiate the anorectic effect of individual drugs with a better safety profile, which deserves further investigation in clinical trials.


Subject(s)
Appetite Depressants/administration & dosage , Diethylpropion/administration & dosage , Topiramate/administration & dosage , Animals , Appetite Depressants/adverse effects , Blood Pressure/drug effects , Diethylpropion/adverse effects , Dose-Response Relationship, Drug , Drug Synergism , Humans , Male , Milk , Rats, Wistar , Topiramate/adverse effects
11.
Biochem Biophys Res Commun ; 494(1-2): 152-157, 2017 12 09.
Article in English | MEDLINE | ID: mdl-29037812

ABSTRACT

Apolipoprotein A-IV (apoA-IV) is a satiation factor that acts in the hypothalamus, however, the intracellular mechanisms responsible for this action are still largely unknown. Here we report that apoA-IV treatment elicited a rapid activation of the phosphatidylinositol-3-kinase (PI3K) signaling pathway in cultured primary hypothalamic neurons, and this effect was significantly attenuated by pretreatment with LY294002, an inhibitor of the PI3K pathway. To determine if the activation of PI3K is required for apoA-IV's inhibitory effect on food intake, apoA-IV was administered intracerebroventricularly. We found that apoA-IV significantly reduced food intake and activated PI3K signaling in the hypothalamus, and these effects were abolished by icv pre-treatment with LY294002. To identify the distinct brain sites where apoA-IV exerts its anorectic action, apoA-IV was administered into the ventromedial hypothalamus (VMH) through implanted bilateral cannula. At a low dose (0.5 µg), apoA-IV significantly inhibited food intake and activated PI3K signaling pathway in the VMH of lean rats, but not in high-fat diet-induced obese (DIO) rats. These results collectively demonstrate a critical role of the PI3K/Akt pathway in apoA-IV's anorectic action in lean rats and suggest a defective PI3K pathway in the VMH is responsible for the impaired apoA-IV's anorectic action in the DIO animals.


Subject(s)
Apolipoproteins A/metabolism , Appetite Depressants/metabolism , Hypothalamus/metabolism , Animals , Apolipoproteins A/administration & dosage , Appetite Depressants/administration & dosage , Cells, Cultured , Diet, High-Fat/adverse effects , Eating/drug effects , Female , Hypothalamus/drug effects , Male , Neurons/drug effects , Neurons/metabolism , Obesity/drug therapy , Obesity/metabolism , Phosphatidylinositol 3-Kinase/metabolism , Pregnancy , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Long-Evans , Signal Transduction/drug effects
12.
Int J Obes (Lond) ; 41(11): 1693-1701, 2017 11.
Article in English | MEDLINE | ID: mdl-28792489

ABSTRACT

OBJECTIVE: High-protein diets (HPDs) are associated with greater satiety and weight loss than diets rich in other macronutrients. The exact mechanisms by which HPDs exert their effects are unclear. However, evidence suggests that the sensing of amino acids produced as a result of protein digestion may have a role in appetite regulation and satiety. We investigated the effects of l-phenylalanine (L-Phe) on food intake and glucose homeostasis in rodents. METHODS: We investigated the effects of the aromatic amino-acid and calcium-sensing receptor (CaSR) agonist l-phenylalanine (L-Phe) on food intake and the release of the gastrointestinal (GI) hormones peptide YY (PYY), glucagon-like peptide-1 (GLP-1) and ghrelin in rodents, and the role of the CaSR in mediating these effects in vitro and in vivo. We also examined the effect of oral l-Phe administration on glucose tolerance in rats. RESULTS: Oral administration of l-Phe acutely reduced food intake in rats and mice, and chronically reduced food intake and body weight in diet-induced obese mice. Ileal l-Phe also reduced food intake in rats. l-Phe stimulated GLP-1 and PYY release, and reduced plasma ghrelin, and also stimulated insulin release and improved glucose tolerance in rats. Pharmacological blockade of the CaSR attenuated the anorectic effect of intra-ileal l-Phe in rats, and l-Phe-induced GLP-1 release from STC-1 and primary L cells was attenuated by CaSR blockade. CONCLUSIONS: l-Phe reduced food intake, stimulated GLP-1 and PYY release, and reduced plasma ghrelin in rodents. Our data provide evidence that the anorectic effects of l-Phe are mediated via the CaSR, and suggest that l-Phe and the CaSR system in the GI tract may have therapeutic utility in the treatment of obesity and diabetes. Further work is required to determine the physiological role of the CaSR in protein sensing in the gut, and the role of this system in humans.


Subject(s)
Appetite Depressants/pharmacology , Appetite Regulation/drug effects , Gastrointestinal Hormones/metabolism , Glucose Intolerance , Phenylalanine/pharmacology , Receptors, Calcium-Sensing/metabolism , Satiation/drug effects , Animals , Appetite Depressants/administration & dosage , Disease Models, Animal , Eating/drug effects , Energy Metabolism , Male , Mice , Mice, Inbred C57BL , Phenylalanine/administration & dosage , Rats , Rats, Wistar , Receptors, Gastrointestinal Hormone/metabolism
13.
Heart Fail Rev ; 22(3): 289-297, 2017 05.
Article in English | MEDLINE | ID: mdl-28417295

ABSTRACT

Pulmonary arterial hypertension (PAH) is a subgroup of PH patients characterized hemodynamically by the presence of pre-capillary PH, defined by a pulmonary artery wedge pressure (PAWP) ≤15 mmHg and a PVR >3 Wood units (WU) in the absence of other causes of pre-capillary PH. According to the current classification, PAH can be associated with exposure to certain drugs or toxins such as anorectic agents, amphetamines, or selective serotonin reuptake inhibitors. With the improvement in awareness and recognition of the drug-induced PAH, it allowed the identification of additional drugs associated with an increased risk for the development of PAH. The supposed mechanism is an increase in the serotonin levels or activation of serotonin receptors that has been demonstrated to act as a growth factor for the pulmonary artery smooth muscle cells and cause progressive obliteration of the pulmonary vasculature. PAH remains a rare complication of several drugs, suggesting possible individual susceptibility, and further studies are needed to identify patients at risk of drug-induced PAH.


Subject(s)
Antineoplastic Agents/adverse effects , Appetite Depressants/administration & dosage , Hypertension, Pulmonary , Pulmonary Wedge Pressure/drug effects , Diagnostic Imaging , Humans , Hypertension, Pulmonary/chemically induced , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/physiopathology , Risk Factors
14.
Expert Opin Emerg Drugs ; 22(1): 87-99, 2017 03.
Article in English | MEDLINE | ID: mdl-27927032

ABSTRACT

INTRODUCTION: The increasing prevalence of obesity represents a huge threat to public health and the current pharmacological treatment options are limited. Bariatric surgery is by far the most effective treatment for severe obesity, highlighting the urgent need for new and improved drug therapies. Areas covered: Based on the physiological regulation of energy homeostasis, pharmacological strategies to treat obesity are evaluated with focus on drugs in phase 2 and 3 clinical development. The potential impact of these drugs on current treatment standards and the barriers for development are discussed and set in a historical perspective of previous antiobesity medications. Expert opinion: The radical effects of bariatric surgery have extended our understanding of the mechanisms controlling appetite and boosted the search for new drug targets in obesity treatment. Accordingly, several compounds targeting the central nervous system and/or periphery are in pipeline for obesity. These drugs should be evaluated over a wide array of end-points; in particular, long-term safety monitoring is necessary as serious adverse events may appear. Combination therapy targeting more than one pathway controlling energy balance might be necessary to achieve substantial weight loss while minimising side effects.


Subject(s)
Anti-Obesity Agents/therapeutic use , Appetite Depressants/therapeutic use , Obesity/drug therapy , Animals , Anti-Obesity Agents/administration & dosage , Anti-Obesity Agents/adverse effects , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Drug Design , Drug Therapy, Combination , Humans , Molecular Targeted Therapy , Time Factors , Weight Loss/drug effects
15.
Crit Rev Food Sci Nutr ; 57(10): 2218-2244, 2017 Jul 03.
Article in English | MEDLINE | ID: mdl-26252442

ABSTRACT

The increasing prevalence of overweight and obesity requires new, effective prevention and treatment strategies. One approach to reduce energy intake is by developing novel foods with increased satiating properties, which may be accomplished by slowing down lipolysis to deliver substrates to the ileum, thereby enhancing natural gut-brain signaling pathways of satiety that are normally induced by meal intake. To develop slow release food additives, their processing in the gastrointestinal tract has to be understood; therefore, we start from a general description of the digestive system and relate that to in vitro modeling, satiety, and lipolytic mechanisms. The effects of physicochemical lipid composition, encapsulation matrix, and interfacial structure on lipolysis are emphasized. We give an overview of techniques and materials used, and discuss partitioning, which may be a key factor for encapsulation performance. Targeted release capsules that delay lipolysis form a real challenge because of the high efficiency of the digestive system; hardly any proof was found that intact orally ingested lipids can be released in the ileum and thereby induce satiety. We expect that this challenge could be tackled with structured o/w-emulsion-based systems that have some protection against lipase, e.g., by hindering bile salt adsorption and/or delaying lipase diffusion.


Subject(s)
Dietary Fats/administration & dosage , Digestion , Down-Regulation , Foods, Specialized , Lipolysis , Models, Biological , Overweight/diet therapy , Animals , Appetite Depressants/administration & dosage , Appetite Depressants/metabolism , Appetite Depressants/therapeutic use , Dietary Fats/metabolism , Dietary Fats/therapeutic use , Emulsions , Energy Intake , Food Additives/metabolism , Food Additives/therapeutic use , Food Technology/trends , Humans , Intestinal Absorption , Overweight/metabolism , Satiety Response
16.
Diabetes Obes Metab ; 19(12): 1751-1761, 2017 12.
Article in English | MEDLINE | ID: mdl-28556449

ABSTRACT

AIMS: There are no treatments for the extreme hyperphagia and obesity in Prader-Willi syndrome (PWS). The bestPWS clinical trial assessed the efficacy, safety and tolerability of the methionine aminopeptidase 2 (MetAP2) inhibitor, beloranib. MATERIALS AND METHODS: Participants with PWS (12-65 years old) were randomly assigned (1:1:1) to biweekly placebo, 1.8 mg beloranib or 2.4 mg beloranib injection for 26 weeks at 15 US sites. Co-primary endpoints were the changes in hyperphagia [measured by Hyperphagia Questionnaire for Clinical Trials (HQ-CT); possible score 0-36] and weight by intention-to-treat. ClinicalTrials.gov registration: NCT02179151. RESULTS: One-hundred and seven participants were included in the intention-to-treat analysis: placebo (n = 34); 1.8 mg beloranib (n = 36); or 2.4 mg beloranib (n = 37). Improvement (reduction) in HQ-CT total score was greater in the 1.8 mg (mean difference -6.3, 95% CI -9.6 to -3.0; P = .0003) and 2.4 mg beloranib groups (-7.0, 95% CI -10.5 to -3.6; P = .0001) vs placebo. Compared with placebo, weight change was greater with 1.8 mg (mean difference - 8.2%, 95% CI -10.8 to -5.6; P < .0001) and 2.4 mg beloranib (-9.5%, 95% CI -12.1 to -6.8; P < .0001). Injection site bruising was the most frequent adverse event with beloranib. Dosing was stopped early due to an imbalance in venous thrombotic events in beloranib-treated participants (2 fatal events of pulmonary embolism and 2 events of deep vein thrombosis) compared with placebo. CONCLUSIONS: MetAP2 inhibition with beloranib produced statistically significant and clinically meaningful improvements in hyperphagia-related behaviours and weight loss in participants with PWS. Although investigation of beloranib has ceased, inhibition of MetAP2 is a novel mechanism for treating hyperphagia and obesity.


Subject(s)
Aminopeptidases/antagonists & inhibitors , Appetite Depressants/therapeutic use , Cinnamates/therapeutic use , Cyclohexanes/therapeutic use , Epoxy Compounds/therapeutic use , Glycoproteins/antagonists & inhibitors , Hyperphagia/prevention & control , Obesity/prevention & control , Prader-Willi Syndrome/drug therapy , Protease Inhibitors/therapeutic use , Sesquiterpenes/therapeutic use , Adolescent , Adult , Aminopeptidases/metabolism , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Body Mass Index , Cinnamates/administration & dosage , Cinnamates/adverse effects , Cyclohexanes/administration & dosage , Cyclohexanes/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Early Termination of Clinical Trials , Epoxy Compounds/administration & dosage , Epoxy Compounds/adverse effects , Female , Glycoproteins/metabolism , Humans , Hyperphagia/etiology , Hyperphagia/physiopathology , Intention to Treat Analysis , Male , Methionyl Aminopeptidases , Obesity/etiology , Prader-Willi Syndrome/physiopathology , Protease Inhibitors/administration & dosage , Protease Inhibitors/adverse effects , Sesquiterpenes/administration & dosage , Sesquiterpenes/adverse effects , Severity of Illness Index , Venous Thrombosis/chemically induced , Venous Thrombosis/physiopathology , Weight Loss/drug effects , Young Adult
17.
Diabetes Obes Metab ; 19(9): 1242-1251, 2017 09.
Article in English | MEDLINE | ID: mdl-28266779

ABSTRACT

AIM: The aim of this trial was to investigate the mechanism of action for body weight loss with semaglutide. MATERIALS AND METHODS: This randomised, double-blind, placebo-controlled, two-period crossover trial investigated the effects of 12 weeks of treatment with once-weekly subcutaneous semaglutide, dose-escalated to 1.0 mg, in 30 subjects with obesity. Ad libitum energy intake, ratings of appetite, thirst, nausea and well-being, control of eating, food preference, resting metabolic rate, body weight and body composition were assessed. RESULTS: After a standardised breakfast, semaglutide, compared with placebo, led to a lower ad libitum energy intake during lunch (-1255 kJ; P < .0001) and during the subsequent evening meal ( P = .0401) and snacks ( P = .0034), resulting in a 24% reduction in total energy intake across all ad libitum meals throughout the day (-3036 kJ; P < .0001). Fasting overall appetite suppression scores were improved with semaglutide vs placebo, while nausea ratings were similar. Semaglutide was associated with less hunger and food cravings, better control of eating and a lower preference for high-fat foods. Resting metabolic rate, adjusted for lean body mass, did not differ between treatments. Semaglutide led to a reduction from baseline in mean body weight of 5.0 kg, predominantly from body fat mass. CONCLUSION: After 12 weeks of treatment, ad libitum energy intake was substantially lower with semaglutide vs placebo with a corresponding loss of body weight observed with semaglutide. In addition to reduced energy intake, likely mechanisms for semaglutide-induced weight loss included less appetite and food cravings, better control of eating and lower relative preference for fatty, energy-dense foods.


Subject(s)
Adiposity/drug effects , Appetite Depressants/therapeutic use , Appetite Regulation/drug effects , Energy Intake/drug effects , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptides/therapeutic use , Obesity/drug therapy , Adult , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Basal Metabolism/drug effects , Body Mass Index , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Feeding Behavior/drug effects , Female , Food Preferences/drug effects , Glucagon-Like Peptide-1 Receptor/metabolism , Glucagon-Like Peptides/administration & dosage , Glucagon-Like Peptides/adverse effects , Humans , Injections, Subcutaneous , Male , Middle Aged , Obesity/metabolism , Self Report , Weight Loss/drug effects
18.
Diabetes Obes Metab ; 19(8): 1165-1170, 2017 08.
Article in English | MEDLINE | ID: mdl-28261955

ABSTRACT

AIMS: Hypothalamic injury-associated obesity (HIAO) results from damage to the hypothalamus that often occurs with surgical removal/radiation therapy of tumours in the hypothalamic region, such as craniopharyngioma. There is currently no rigorously studied pharmaceutical treatment for the intractable weight gain and cardiometabolic consequences that occur in patients with HIAO. We aimed to assess efficacy, safety and tolerability of beloranib treatment for 4 to 8 weeks in patients with HIAO. MATERIALS AND METHODS: This Phase 2a, double-blind, placebo-controlled study included 14 patients with HIAO, randomized to receive beloranib 1.8 mg or placebo subcutaneously twice weekly for 4 weeks with an optional 4-week open-label extension in which all patients received beloranib. The primary endpoint was change in weight from baseline to Week 4. RESULTS: Participants were 64% female, with a mean (SD) age of 32 (9) years, BMI of 43 (7) kg/m2 and weight of 126 (22) kg. Compared with placebo (N = 4), beloranib 1.8 mg (N = 8) resulted in a mean (95% CI) difference in weight of -3.2 (-5.4, -0.9) kg after 4 weeks. Weight loss continued through the 8 weeks in patients randomized to beloranib (mean -6.2 [-8.2, -4.1] kg). Beloranib treatment was associated with improvements in high-sensitivity CRP. Adverse events were mild to moderate. No patients who received beloranib discontinued treatment. CONCLUSION: Beloranib treatment resulted in progressive weight loss in patients with HIAO that was comparable to that observed with beloranib in patients with exogenous obesity. These findings indicate a novel mechanism for treating obesity in patients with HIAO.


Subject(s)
Aminopeptidases/antagonists & inhibitors , Appetite Depressants/therapeutic use , Cardiovascular Diseases/prevention & control , Cinnamates/therapeutic use , Cyclohexanes/therapeutic use , Epoxy Compounds/therapeutic use , Glycoproteins/antagonists & inhibitors , Hypothalamus/injuries , Metabolic Syndrome/prevention & control , Obesity, Morbid/drug therapy , Sesquiterpenes/therapeutic use , Adult , Aminopeptidases/metabolism , Appetite Depressants/administration & dosage , Appetite Depressants/adverse effects , Biomarkers/blood , Body Mass Index , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/etiology , Cinnamates/administration & dosage , Cinnamates/adverse effects , Cohort Studies , Cyclohexanes/administration & dosage , Cyclohexanes/adverse effects , Double-Blind Method , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/adverse effects , Enzyme Inhibitors/therapeutic use , Epoxy Compounds/administration & dosage , Epoxy Compounds/adverse effects , Female , Follow-Up Studies , Glycoproteins/metabolism , Humans , Injections, Subcutaneous , Male , Metabolic Syndrome/epidemiology , Metabolic Syndrome/etiology , Methionyl Aminopeptidases , Obesity, Morbid/blood , Obesity, Morbid/etiology , Obesity, Morbid/physiopathology , Proof of Concept Study , Risk , Sesquiterpenes/administration & dosage , Sesquiterpenes/adverse effects , Weight Loss/drug effects , Young Adult
19.
Appetite ; 108: 57-67, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27663531

ABSTRACT

This research investigated the effect of modifying the aftertaste of potato crisps on (1) temporal sensory perception and (2) appetite using three mouthwash conditions (no mouthwash, a water mouthwash, and a menthol mouthwash). For the sensory study, 17 screened female subjects were trained on the Temporal Dominance of Sensations (TDS) methodology. Subjects undertook TDS to monitor all sensory attributes during the mastication of a 2 g crisp until swallowing (at 20s), then conducted the mouthwash, and then continued the TDS task to monitor aftertaste until 90s. For the appetite study, 36 subjects (18 male, 18 female) completed 100 mm Visual Analogue Scales (VAS) for desire, liking, hunger, and thirst, followed by an ad libitum eating task. For the VAS scales testing, subjects chewed and swallowed a 2 g crisp, and then immediately conducted the mouthwash before completing the VAS scales. For the ad libitum task, subjects were given 12 min to consume as many crisps as they desired on a plate (up to 50 g). Every three minutes they were required to conduct a mouthwash. TDS results showed that in comparison with no mouthwash, the water mouthwash significantly reduced aftertaste attributes such as savoury, salty, and fatty mouthcoating, and the menthol mouthwash significantly increased aftertaste attributes of cooling, minty, and tingly. The water mouthwash did not influence desire and liking of crisps, or hunger and thirst. The water mouthwash did not influence ad libitum intake of the crisps over a 12 min period. The menthol mouthwash significantly reduced desire and liking of the crisps, as well as hunger and thirst. Furthermore, the menthol mouthwash significantly reduced ad libitum crisp intake by 29% over the 12 min period.


Subject(s)
Energy Intake , Fast Foods/adverse effects , Food Preferences , Menthol/administration & dosage , Mouthwashes/administration & dosage , Plant Roots/chemistry , Solanum tuberosum/chemistry , Adolescent , Adult , Appetite Depressants/administration & dosage , Appetite Regulation , Female , Humans , Hunger , Male , Sensation , Taste , Taste Perception , Thirst , Young Adult
20.
Int J Obes (Lond) ; 40(11): 1707-1714, 2016 11.
Article in English | MEDLINE | ID: mdl-27553712

ABSTRACT

BACKGROUND/OBJECTIVES: Animal studies and pilot experiments in men indicate that the hypothalamic neuropeptide oxytocin limits food intake, and raise the question of its potential to improve metabolic control in obesity. SUBJECTS/METHODS: We compared the effect of central nervous oxytocin administration (24 IU) via the intranasal route on ingestive behaviour and metabolic function in 18 young obese men with the results in a group of 20 normal-weight men. In double-blind, placebo-controlled experiments, ad libitum food intake from a test buffet was examined in fasted subjects 45 min after oxytocin administration, followed by the assessment of postprandial, reward-driven snack intake. Energy expenditure was repeatedly assessed by indirect calorimetry and blood was sampled to determine concentrations of blood glucose and hormones. RESULTS: Oxytocin markedly reduced hunger-driven food intake in the fasted state in obese but not in normal-weight men, and led to a reduction in snack consumption in both groups, whereas energy expenditure remained generally unaffected. Hypothalamic-pituitary-adrenal axis secretion and the postprandial rise in plasma glucose were blunted by oxytocin in both groups. CONCLUSIONS: Oxytocin exerts an acutely inhibitory impact on food intake that is enhanced rather than decreased in obese compared with normal-weight men. This pattern puts it in contrast to other metabolically active neuropeptides and bodes well for clinical applications of oxytocin in the treatment of metabolic disorders.


Subject(s)
Appetite Depressants/pharmacology , Eating/drug effects , Feeding Behavior/drug effects , Obesity/physiopathology , Oxytocin/pharmacology , Administration, Intranasal , Adult , Appetite Depressants/administration & dosage , Case-Control Studies , Cross-Over Studies , Double-Blind Method , Eating/physiology , Eating/psychology , Energy Intake/drug effects , Energy Intake/physiology , Energy Metabolism/drug effects , Energy Metabolism/physiology , Feeding Behavior/physiology , Germany , Humans , Hypothalamo-Hypophyseal System , Male , Obesity/drug therapy , Obesity/prevention & control , Oxytocin/administration & dosage , Pituitary-Adrenal System , Postprandial Period/physiology , Treatment Outcome
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