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Armeli F, Bonucci A, Maggi E, Pinto A, Businaro R. Mediterranean Diet and Neurodegenerative Diseases: The Neglected Role of Nutrition in the Modulation of the Endocannabinoid System. Biomolecules 2021; 11:biom11060790. [PMID: 34073983 PMCID: PMC8225112 DOI: 10.3390/biom11060790] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 12/17/2022] Open
Abstract
Neurodegenerative disorders are a widespread cause of morbidity and mortality worldwide, characterized by neuroinflammation, oxidative stress and neuronal depletion. The broad-spectrum neuroprotective activity of the Mediterranean diet is widely documented, but it is not yet known whether its nutritional and caloric balance can induce a modulation of the endocannabinoid system. In recent decades, many studies have shown how endocannabinoid tone enhancement may be a promising new therapeutic strategy to counteract the main hallmarks of neurodegeneration. From a phylogenetic point of view, the human co-evolution between the endocannabinoid system and dietary habits could play a key role in the pro-homeostatic activity of the Mediterranean lifestyle: this adaptive balance among our ancestors has been compromised by the modern Western diet, resulting in a “clinical endocannabinoid deficiency syndrome”. This review aims to evaluate the evidence accumulated in the literature on the neuroprotective, immunomodulatory and antioxidant properties of the Mediterranean diet related to the modulation of the endocannabinoid system, suggesting new prospects for research and clinical interventions against neurodegenerative diseases in light of a nutraceutical paradigm.
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Affiliation(s)
- Federica Armeli
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica, 79, 04100 Latina, Italy; (F.A.); (A.B.); (E.M.)
| | - Alessio Bonucci
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica, 79, 04100 Latina, Italy; (F.A.); (A.B.); (E.M.)
| | - Elisa Maggi
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica, 79, 04100 Latina, Italy; (F.A.); (A.B.); (E.M.)
| | - Alessandro Pinto
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
| | - Rita Businaro
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica, 79, 04100 Latina, Italy; (F.A.); (A.B.); (E.M.)
- Correspondence:
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Tarragon E, Moreno JJ. Cannabinoids, Chemical Senses, and Regulation of Feeding Behavior. Chem Senses 2020; 44:73-89. [PMID: 30481264 DOI: 10.1093/chemse/bjy068] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The herb Cannabis sativa has been traditionally used in many cultures and all over the world for thousands of years as medicine and recreation. However, because it was brought to the Western world in the late 19th century, its use has been a source of controversy with respect to its physiological effects as well as the generation of specific behaviors. In this regard, the CB1 receptor represents the most relevant target molecule of cannabinoid components on nervous system and whole-body energy homeostasis. Thus, the promotion of CB1 signaling can increase appetite and stimulate feeding, whereas blockade of CB1 suppresses hunger and induces hypophagia. Taste and flavor are sensory experiences involving the oral perception of food-derived chemicals and drive a primal sense of acceptable or unacceptable for what is sampled. Therefore, research within the last decades focused on deciphering the effect of cannabinoids on the chemical senses involved in food perception and consequently in the pattern of feeding. In this review, we summarize the data on the effect of cannabinoids on chemical senses and their influences on food intake control and feeding behavior.
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Affiliation(s)
- Ernesto Tarragon
- Department of Psychobiology, Faculty of Health Sciences, University Jaume I of Castellon, Castellon, Spain.,Department of Psychobiology and Methodology on Behavioral Sciences, Faculty of Psychology, Universidad Complutense de Madrid, Campus de Somosaguas, Ctra. de Húmera, Madrid, Spain
| | - Juan José Moreno
- Department of Nutrition, Food Sciences and Gastronomy, Institute of Nutrition and Food Safety, University of Barcelona, Campus Torribera, Barcelona, Spain.,IBEROBN Fisiopatologia de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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3
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Christie S, Wittert GA, Li H, Page AJ. Involvement of TRPV1 Channels in Energy Homeostasis. Front Endocrinol (Lausanne) 2018; 9:420. [PMID: 30108548 PMCID: PMC6079260 DOI: 10.3389/fendo.2018.00420] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/04/2018] [Indexed: 12/25/2022] Open
Abstract
The ion channel TRPV1 is involved in a wide range of processes including nociception, thermosensation and, more recently discovered, energy homeostasis. Tightly controlling energy homeostasis is important to maintain a healthy body weight, or to aid in weight loss by expending more energy than energy intake. TRPV1 may be involved in energy homeostasis, both in the control of food intake and energy expenditure. In the periphery, it is possible that TRPV1 can impact on appetite through control of appetite hormone levels or via modulation of gastrointestinal vagal afferent signaling. Further, TRPV1 may increase energy expenditure via heat production. Dietary supplementation with TRPV1 agonists, such as capsaicin, has yielded conflicting results with some studies indicating a reduction in food intake and increase in energy expenditure, and other studies indicating the converse. Nonetheless, it is increasingly apparent that TRPV1 may be dysregulated in obesity and contributing to the development of this disease. The mechanisms behind this dysregulation are currently unknown but interactions with other systems, such as the endocannabinoid systems, could be altered and therefore play a role in this dysregulation. Further, TRPV1 channels appear to be involved in pancreatic insulin secretion. Therefore, given its plausible involvement in regulation of energy and glucose homeostasis and its dysregulation in obesity, TRPV1 may be a target for weight loss therapy and diabetes. However, further research is required too fully elucidate TRPV1s role in these processes. The review provides an overview of current knowledge in this field and potential areas for development.
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Affiliation(s)
- Stewart Christie
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Gary A. Wittert
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Hui Li
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Amanda J. Page
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
- *Correspondence: Amanda J. Page
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Fride E, Bregman T, Kirkham TC. Endocannabinoids and Food Intake: Newborn Suckling and Appetite Regulation in Adulthood. Exp Biol Med (Maywood) 2016; 230:225-34. [PMID: 15792943 DOI: 10.1177/153537020523000401] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The appetite-stimulating effects of the cannabis plant (Cannabis sativa) have been known since ancient times, and appear to be effected through the incentive and rewarding properties of foods. Investigations into the biological basis of the multiple effects of cannabis have yielded important breakthroughs in recent years: the discovery of two cannabinoid receptors in brain and peripheral organ systems, and endogenous ligands (endocannabinoids) for these receptors. These advances have greatly increased our understanding of how appetite is regulated through these endocannabinoid receptor systems. The presence of endocannabinoids in the developing brain and in maternal milk have led to evidence for a critical role for CB, receptors in oral motor control of suckling during neonatal development. The endocannabinoids appear to regulate energy balance and food intake at four functional levels within the brain and periphery: (i) limbic system (for hedonic evaluation of foods), (ii) hypothalamus and hindbrain (integrative functions), (iii) intestinal system, and (iv) adipose tissue. At each of these levels, the endocannabinoid system interacts with a number of better known molecules involved in appetite and weight regulation, including leptin, ghrelin, and the melanocortins. Therapeutically, appetite stimulation by cannabinoids has been studied for several decades, particularly in relation to cachexia and malnutrition associated with cancer, acquired immunodeficiency syndrome, or anorexia nervosa. The recent advances in cannabinoid pharmacology may lead to improved treatments for these conditions or, conversely, for combating excessive appetite and body weight, such as CB, receptor antagonists as antiobesity medications. In conclusion, the exciting progress in the understanding of how the endocannabinoid CB receptor systems influence appetite and body weight is stimulating the development of therapeutic orexigenic and anorectic agents. Furthermore, the role of cannabinoid CB, receptor activation for milk suckling in newborns may open new doors toward understanding nonorganic failure-to-thrive in infants, who display growth failure without known organic cause.
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Affiliation(s)
- Ester Fride
- Department of Behavioral Sciences, College of Judea and Samaria, Ariel, Israel.
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Gold MS, Badgaiyan RD, Blum K. A Shared Molecular and Genetic Basis for Food and Drug Addiction: Overcoming Hypodopaminergic Trait/State by Incorporating Dopamine Agonistic Therapy in Psychiatry. Psychiatr Clin North Am 2015; 38:419-62. [PMID: 26300032 DOI: 10.1016/j.psc.2015.05.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This article focuses on the shared molecular and neurogenetics of food and drug addiction tied to the understanding of reward deficiency syndrome. Reward deficiency syndrome describes a hypodopaminergic trait/state that provides a rationale for commonality in approaches for treating long-term reduced dopamine function across the reward brain regions. The identification of the role of DNA polymorphic associations with reward circuitry has resulted in new understanding of all addictive behaviors.
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Affiliation(s)
- Mark S Gold
- Departments of Psychiatry & Behavioral Sciences, Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA 90033, USA; Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Rivermend Health Scientific Advisory Board, 2300 Windy Ridge Parkway South East, Suite 210S, Atlanta, GA 30339, USA; Drug Enforcement Administration (DEA) Educational Foundation, Washington, DC, USA.
| | - Rajendra D Badgaiyan
- Laboratory of Advanced Radiochemistry and Molecular and Functioning Imaging, Department of Psychiatry, College of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Kenneth Blum
- Department of Psychiatry, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, USA; Department of Psychiatry, Center for Clinical & Translational Science, Community Mental Health Institute, University of Vermont College of Medicine, University of Vermont, Burlington, VT, USA; Division of Applied Clinical Research, Dominion Diagnostics, LLC, 211 Circuit Drive, North Kingstown, RI 02852, USA; Rivermend Health Scientific Advisory Board, Atlanta, GA, USA
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Abstract
OBJECTIVE Palatable foods are frequently high in energy density. Chronic consumption of high-energy density foods can contribute to the development of cardiometabolic pathology including obesity, diabetes, and cardiovascular disease. This article reviews the contributions of extrinsic and intrinsic factors that influence the reward components of food intake. METHODS A narrative review was conducted to determine the behavioral and central nervous system (CNS) related processes involved in the reward components of high-energy density food intake. RESULTS The rewarding aspects of food, particularly palatable and preferred foods, are regulated by CNS circuitry. Overlaying this regulation is modulation by intrinsic endocrine systems and metabolic hormones relating to energy homeostasis, developmental stage, or gender. It is now recognized that extrinsic or environmental factors, including ambient diet composition and the provocation of stress or anxiety, also contribute substantially to the expression of food reward behaviors such as motivation for, and seeking of, preferred foods. CONCLUSIONS High-energy density food intake is influenced by both physiological and pathophysiological processes. Contextual, behavioral, and psychological factors and CNS-related processes represent potential targets for multiple types of therapeutic intervention.
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Affiliation(s)
- Dianne P Figlewicz
- From the BSR&D Program, VA Puget Sound Health Care System, Seattle, Washington; and the Department of Psychiatry & Behavioral Sciences, University of Washington School of Medicine, Seattle, Washington
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7
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Paracetamol potentiates the antidepressant-like and anticompulsive-like effects of fluoxetine. Behav Pharmacol 2015; 26:268-81. [DOI: 10.1097/fbp.0000000000000104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Borgquist A, Meza C, Wagner EJ. The role of AMP-activated protein kinase in the androgenic potentiation of cannabinoid-induced changes in energy homeostasis. Am J Physiol Endocrinol Metab 2015; 308:E482-95. [PMID: 25550281 PMCID: PMC4360013 DOI: 10.1152/ajpendo.00421.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Orexigenic mediators can impact the hypothalamic feeding circuitry via the activation of AMP-dependent protein kinase (AMPK). Given that testosterone is an orexigenic hormone, we hypothesized that androgenic changes in energy balance are due to enhanced cannabinoid-induced inhibition of anorexigenic proopiomelanocortin (POMC) neurons via activation of AMPK. To this end, whole animal experiments were carried out in gonadectomized male guinea pigs treated subcutaneously with either testosterone propionate (TP; 400 μg) or its sesame oil vehicle (0.1 ml). TP-treated animals displayed increases in energy intake associated with increases in meal size. TP also increased several indices of energy expenditure as well as the p-AMPK/AMPK ratio in the arcuate nucleus (ARC) measured 2 and 24 h posttreatment. Subcutaneous administration of the CB1 receptor antagonist AM251 (3 mg/kg) rapidly blocked the hyperphagic effect of TP. This was mimicked largely upon third ventricular administration of AM251 (10 μg). Electrophysiological studies revealed that TP potentiated the ability of the cannabinoid receptor agonist WIN 55,212-2 to decrease the frequency of miniature excitatory postsynaptic currents in ARC neurons. TP also increased the basal frequency of miniature inhibitory postsynaptic currents. In addition, depolarization-induced suppression (DSE) is potentiated in cells from TP-treated animals and blocked by AM251. The AMPK inhibitor compound C attenuated DSE from TP-treated animals, whereas the AMPK activator metformin enhanced DSE from vehicle-treated animals. These effects occurred in a sizable number of identified POMC neurons. Collectively, these results indicate that the androgen-induced increases in energy intake are mediated via an AMPK-dependent augmentation in endocannabinoid tone onto POMC neurons.
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Affiliation(s)
- Amanda Borgquist
- Department of Basic Medical Sciences, College of Osteopathic Medicine, Western University of Health Sciences, Pomona, California
| | - Cecilia Meza
- Department of Basic Medical Sciences, College of Osteopathic Medicine, Western University of Health Sciences, Pomona, California
| | - Edward J Wagner
- Department of Basic Medical Sciences, College of Osteopathic Medicine, Western University of Health Sciences, Pomona, California
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9
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Scherma M, Fattore L, Satta V, Businco F, Pigliacampo B, Goldberg SR, Dessi C, Fratta W, Fadda P. Pharmacological modulation of the endocannabinoid signalling alters binge-type eating behaviour in female rats. Br J Pharmacol 2014; 169:820-33. [PMID: 23072421 DOI: 10.1111/bph.12014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Revised: 09/03/2012] [Accepted: 09/12/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Binge eating disorder (BED) is characterized by excessive food intake during short periods of time. Recent evidence suggests that alterations in the endocannabinoid signalling could be involved in the pathophysiology of BED. In this study, we investigated whether pharmacological manipulation of endocannabinoid transmission may be effective in modulating the aberrant eating behaviour present in a validated rat model of BED. EXPERIMENTAL APPROACH Binge-type eating was induced in female rats by providing limited access to an optional source of dietary fat (margarine). Rats were divided into three groups, all with ad libitum access to chow and water: control (C), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days a week; high restriction (HR), with 2 h margarine access 3 days a week. KEY RESULTS Compared with the LR group, the HR group consumed more margarine and this was accompanied by an increase in body weight. The cannabinoid CB₁/CB₂ receptor agonist Δ⁹-tetrahydrocannabinol significantly increased margarine intake selectively in LR rats, while the fatty acid amide hydrolase inhibitor URB597 showed no effect. The CB₁ receptor inverse agonist/antagonist rimonabant dose-dependently reduced margarine intake in HR rats. Notably, in HR rats, chronic treatment with a low dose of rimonabant induced a selective long-lasting reduction in margarine intake that did not develop tolerance, and a significant and persistent reduction in body weight. CONCLUSIONS AND IMPLICATIONS Chronic pharmacological blockade of CB₁ receptors reduces binge eating behaviour in female rats and may prove effective in treating BED, with an associated significant reduction in body weight.
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Affiliation(s)
- M Scherma
- Department of Biomedical Science, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, Monserrato (Cagliari), Italy
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Abstract
Relieving the suffering associated with cancer and its treatment in the physical, emotional, practical, and spiritual domains is impossible without impeccable symptom control. This review summarizes key features essential to the management of: anorexia/cachexia, bowel obstruction, diarrhea, fatigue, mucositis, and nausea/vomiting. Taken together, these are some of the most vexing symptoms for cancer patients. Well-managed symptoms enable the course of overall cancer care to be unimpeded.
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Yarnell S, Oscar-Berman M, Avena N, Blum K, Gold M. Pharmacotherapies for Overeating and Obesity. ACTA ACUST UNITED AC 2013; 4:131. [PMID: 23826512 DOI: 10.4172/2157-7412.1000131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Obesity has become pandemic, and the annual cost in related illnesses and loss of productivity is already over $100 billion and rising. Research has shown that obesity can and does cause changes in behavior and in the brain itself that are very similar to changes caused by drugs of abuse. While food addiction is not the causal agent of all obesity, it is clear that many people no longer eat to survive, but instead survive to eat. This review considers the importance of the brain's reward system in food intake. The review also examines research developments and current treatments for obesity, including diet and exercise, psychotherapy, surgical interventions, and pharmacotherapies. Finally we discuss alterations in American society that are necessary for change to occur, and the diffculties therein.
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Affiliation(s)
- S Yarnell
- Department of Psychiatry and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida, USA
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Perelló M, Zigman JM. The role of ghrelin in reward-based eating. Biol Psychiatry 2012; 72:347-53. [PMID: 22458951 PMCID: PMC3388148 DOI: 10.1016/j.biopsych.2012.02.016] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/03/2012] [Accepted: 02/17/2012] [Indexed: 01/18/2023]
Abstract
The peptide hormone ghrelin acts in the central nervous system as a potent orexigenic signal. Not only is ghrelin recognized as playing an important role in feeding circuits traditionally thought of as affecting body weight homeostasis, but also an accumulating number of scientific studies have identified ghrelin as being a key regulator of reward-based, hedonic eating behaviors. In the current article, we review ghrelin's orexigenic actions, the evidence linking ghrelin to food reward behavior, potential mechanisms by which ghrelin mediates reward-based eating behavior, and those studies suggesting an obligatory role for ghrelin in the changed eating behaviors induced by stress.
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Affiliation(s)
- Mario Perelló
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology (IMBICE-CONICET/CICPBA), Calle 526 s/n entre 10 y 11, La Plata, Buenos Aires, Argentina 1900
| | - Jeffrey M. Zigman
- Department of Internal Medicine (Divisions of Hypothalamic Research and of Endocrinology & Metabolism), The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390-9077,Department of Psychiatry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390-9077
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13
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de Luis DA, Aller R, Izaola O, Conde R, Sagrado MG, Primo D, Castro MJ. Relationship among metabolic syndrome, C358A polymorphism of the endocannabinoid degrading enzyme fatty acid amide hydrolase (FAAH) and insulin resistance. J Diabetes Complications 2012; 26:328-32. [PMID: 22609216 DOI: 10.1016/j.jdiacomp.2012.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 04/02/2012] [Accepted: 04/06/2012] [Indexed: 11/21/2022]
Abstract
BACKGROUND It has been demonstrated that the polymorphism 385 C/A of FAAH (fatty acid amide hydrolase) was associated with obesity and metabolic disorders. OBJECTIVE The aim of our study was to investigate the relationship of the polymorphism (cDNA 385 C->A) of FAAH gene and insulin resistance in obese patients with and without metabolic syndrome. DESIGN A population of 799 obese patients was analyzed in cross-sectional survey. A bioimpedance, blood pressure, serial assessment of nutritional intake with 3 days written food records and biochemical analysis were performed. Genotype of FAAH gene polymorphism was studied. RESULTS Prevalence of metabolic syndrome (MS) with ATP III definition was 49.8% (398 patients) and 50.2% patients without MS (n=401 patients). Prevalence of FAAH genotypes was similar in patients with metabolic syndrome (69.6% wild genotype and 30.4% mutant genotype) and without metabolic syndrome (66.6% wild genotype and 33.4% mutant genotype). In patients without metabolic syndrome, insulin and HOMA levels were higher in mutant genotype than wild type group. CONCLUSION The main finding is the lack of association of the FAAH genotypes with metabolic syndrome prevalence. Patients with mutant genotype group of FAAH gene and without metabolic syndrome have higher insulin and HOMA levels than wild type group.
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Affiliation(s)
- D A de Luis
- Center of Investigation of Endocrinology and Clinical Nutrition, Medicine School and Unit of Investigation, Hospital Rio Hortega, University of Valladolid, Valladolid, Spain.
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Weston-Green K, Huang XF, Deng C. Alterations to melanocortinergic, GABAergic and cannabinoid neurotransmission associated with olanzapine-induced weight gain. PLoS One 2012; 7:e33548. [PMID: 22438946 PMCID: PMC3306411 DOI: 10.1371/journal.pone.0033548] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 02/11/2012] [Indexed: 12/30/2022] Open
Abstract
Background/Aim Second generation antipsychotics (SGAs) are used to treat schizophrenia but can cause serious metabolic side-effects, such as obesity and diabetes. This study examined the effects of low to high doses of olanzapine on appetite/metabolic regulatory signals in the hypothalamus and brainstem to elucidate the mechanisms underlying olanzapine-induced obesity. Methodology/Results Levels of pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and glutamic acid decarboxylase (GAD65, enzyme for GABA synthesis) mRNA expression, and cannabinoid CB1 receptor (CB1R) binding density (using [3H]SR-141716A) were examined in the arcuate nucleus (Arc) and dorsal vagal complex (DVC) of female Sprague Dawley rats following 0.25, 0.5, 1.0 or 2.0 mg/kg olanzapine or vehicle (3×/day, 14-days). Consistent with its weight gain liability, olanzapine significantly decreased anorexigenic POMC and increased orexigenic NPY mRNA expression in a dose-sensitive manner in the Arc. GAD65 mRNA expression increased and CB1R binding density decreased in the Arc and DVC. Alterations to neurotransmission signals in the brain significantly correlated with body weight and adiposity. The minimum dosage threshold required to induce weight gain in the rat was 0.5 mg/kg olanzapine. Conclusions Olanzapine-induced weight gain is associated with reduced appetite-inhibiting POMC and increased NPY. This study also supports a role for the CB1R and GABA in the mechanisms underlying weight gain side-effects, possibly by altering POMC transmission. Metabolic dysfunction can be modelled in the female rat using low, clinically-comparable olanzapine doses when administered in-line with the half-life of the drug.
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Affiliation(s)
- Katrina Weston-Green
- Centre for Translational Neuroscience, School of Health Sciences, University of Wollongong, Wollongong, Australia
- Schizophrenia Research Institute, Darlinghurst, Australia
| | - Xu-Feng Huang
- Centre for Translational Neuroscience, School of Health Sciences, University of Wollongong, Wollongong, Australia
- Schizophrenia Research Institute, Darlinghurst, Australia
| | - Chao Deng
- Centre for Translational Neuroscience, School of Health Sciences, University of Wollongong, Wollongong, Australia
- Schizophrenia Research Institute, Darlinghurst, Australia
- * E-mail:
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Abstract
Cannabis sativa has been used since antiquity to treat many ailments, including eating disorders. The primary psychoactive constituent of this plant, Δ(9) -tetrahydrocannabinol (THC) is an FDA approved medication to treat nausea and emesis caused by cancer chemotherapeutic agents as well as to stimulate appetite in AIDS patients suffering from cachexia. The effects of THC are mediated through the endocannabinoid system (ECS), which promotes a positive energy balance through stimulation of appetite as well as shifting homeostatic mechanisms toward energy storage. Here we discuss the physiological function of the ECS in energy balance and the therapeutic potential of targeting this system.
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Affiliation(s)
| | - Aron H. Lichtman
- Correspondence to: Aron H. Lichtman, PhD, Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298.
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Bello NT, Coughlin JW, Redgrave GW, Ladenheim EE, Moran TH, Guarda AS. Dietary conditions and highly palatable food access alter rat cannabinoid receptor expression and binding density. Physiol Behav 2011; 105:720-6. [PMID: 22005165 DOI: 10.1016/j.physbeh.2011.09.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/15/2011] [Accepted: 09/29/2011] [Indexed: 11/29/2022]
Abstract
Endogenous cannabinoid signaling, mediated predominately by CB1 receptor activation, is involved in food intake control and body weight regulation. Despite advances in determining the role of the CB1 receptor in obesity, its involvement in the driven nature of eating pathologies has received little attention. The present study examined CB1 receptor alterations as a consequence of dietary-induced binge eating in female Sprague Dawley rats. Four control groups were used to control for calorie restriction and highly palatable food variables characterizing this behavioral model. All groups were kept on their respective feeding schedules for 6-weeks and were given a uniform 33% calorie restriction (~22 h food deprivation) prior to sacrifice. Our findings indicate that regional CB1 mRNA and density were influenced by dietary conditions, but were not specific to the dietary-induced binge eating paradigm used. An increase of approximately 50% (compared with naive controls) in CB1 receptor mRNA levels in the nucleus of the solitary tract as measured by in situ hybridization was found in animals receiving continuous access to a highly palatable food (i.e., vegetable shortening with 10% sucrose). This group also had a significant increase in body weight and adiposity. An approximate 20% reduction in CB1 mRNA was observed in the cingulate cortex (areas 1 and 2) in animals exposed to an intermittent schedule of feeding, compared with groups that had ad libitum feeding schedules (i.e., continuous access and naive controls). Receptor density as measured by [(3)H]CP55,940 autoradiography, was reduced by approximately 30% in the nucleus accumbens shell region in groups receiving repeated access to the highly palatable food. Taken together, these findings indicate that dietary conditions can differentially influence CB1 receptors in forebrain and hindbrain regions.
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Affiliation(s)
- Nicholas T Bello
- Department of Animal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
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Involvement of endocannabinoids in antidepressant and anti-compulsive effect of fluoxetine in mice. Behav Brain Res 2011; 223:125-34. [DOI: 10.1016/j.bbr.2011.04.031] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/11/2011] [Accepted: 04/20/2011] [Indexed: 01/17/2023]
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Sztrokay A, Gutyrchik E, Reiser M, Meindl T. Funktionelle MRT und neurophysiologische Aspekte der Adipositas. Radiologe 2011; 51:384-7. [DOI: 10.1007/s00117-010-2089-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Strickler AG, Soares D. Comparative genetics of the central nervous system in epigean and hypogean Astyanax mexicanus. Genetica 2011; 139:383-91. [PMID: 21318738 DOI: 10.1007/s10709-011-9557-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 01/27/2011] [Indexed: 02/02/2023]
Abstract
The extreme environment of subterranean caves presents an adaptive challenge to troglobitic organisms. The mechanisms by which natural selection modify an ancestral surface neural circuit to produce a novel subterranean behavior remain a mystery. To address this question, we performed cross species microarray experiments to compare differences in gene expression levels in the adult brain of the teleost Astyanax mexicanus. This species provides a unique opportunity for comparative genetic studies as it consists of extant epigean (surface) and hypogean (cave) conspecifics. Microarray experiments herein revealed significant changes in transcription levels of seventeen genes, several of which are important for behaviors involved in metabolic management. We focused on genes central to three neurotransmission and neuromodulation networks: the endocannabinoid system (Cannabinoid receptor CB1), the dopaminergic system (Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein) and the glutamatergic system (glutamate receptor AMPA 2a). All three genes were upregulated in the hypogean form of A. mexicanus compared to the epigean form, indicating that behavioral differences in the hypogean form of the species could be due to alterations in expression levels of several key genes. This information provides insights into the complex relationships among environmental factors, genetics, nervous systems and adaptive behavior, and can subsequently help us understand how these interactions affect behavior in other biological systems.
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Ishiguro H, Onaivi ES, Horiuchi Y, Imai K, Komaki G, Ishikawa T, Suzuki M, Watanabe Y, Ando T, Higuchi S, Arinami T. Functional polymorphism in the GPR55 gene is associated with anorexia nervosa. Synapse 2010; 65:103-8. [DOI: 10.1002/syn.20821] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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De Luis DA, González Sagrado M, Aller R, Izaola O, Conde R, Romero E. [C358A polymorphism of the endocannabinoid degrading enzyme fatty acid amide hydrolase (FAAH) and adipocytokine levels in the morbidly obese]. ENDOCRINOLOGIA Y NUTRICION : ORGANO DE LA SOCIEDAD ESPANOLA DE ENDOCRINOLOGIA Y NUTRICION 2010; 57:54-59. [PMID: 20189896 DOI: 10.1016/j.endonu.2010.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Revised: 12/28/2009] [Accepted: 01/04/2010] [Indexed: 05/28/2023]
Abstract
INTRODUCTION The 385 C/A polymorphism of fatty acid amide hydrolase (FAAH) has recently been demonstrated to be associated with overweight and obesity. The aim of our study was to investigate the association between missense polymorphism (cDNA 385 C->A) of the FAAH gene and anthropometric parameters, cardiovascular risk factors and adipocytokines in morbidly obese patients. MATERIAL AND METHODS A sample of 66 morbidly obese patients was analyzed. In all patients, weight, blood pressure, fasting glycemia, lipoprotein(a), C-reactive protein, insulin, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglyceride and adipocytokine levels, as well as the genotype of the C358A polymorphism of FAAH, were determined. RESULTS The mean age was 48.0(16.1) years and the mean body mass index was 44.4 (4.1). There were 17 males (25.8%) and 49 females (74.2%). Forty-five patients (8 males/37 females) (68.2%) were G358G (wild genotype) and 21 patients (4 males/17 females) were G358A (31.8%) (mutant group). Biochemical, anthropometrical and adipocytokine levels showed no statistically significant differences between the two genotypes. CONCLUSION In patients with morbid obesity, the C358A polymorphism of FAAH was not associated with anthropometric parameters, biochemical markers or adipocytokine levels.
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Affiliation(s)
- Daniel A De Luis
- Instituto de Endocrinología y Nutrición, Unidad de Investigación, Facultad de Medicina, Hospital Río Hortega, Universidad de Valladolid (RETICEF 056/0013), Valladolid, Spain.
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Van Vugt DA. Brain imaging studies of appetite in the context of obesity and the menstrual cycle. Hum Reprod Update 2009; 16:276-92. [DOI: 10.1093/humupd/dmp051] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Støving RK, Andries A, Brixen K, Flyvbjerg A, Hørder K, Frystyk J. Leptin, ghrelin, and endocannabinoids: potential therapeutic targets in anorexia nervosa. J Psychiatr Res 2009; 43:671-9. [PMID: 18926548 DOI: 10.1016/j.jpsychires.2008.09.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 08/30/2008] [Accepted: 09/12/2008] [Indexed: 11/18/2022]
Abstract
Anorexia nervosa (AN) has the highest mortality rate between psychiatric disorders, and evidence for managing it is still very limited. So far, pharmacological treatment has focused on a narrow range of drugs and only a few controlled studies have been performed. Furthermore, the studies have been of short duration and included a limited number of subjects, often heterogenic with regard to stage and acute nutritive status. Thus, novel approaches are urgently needed. Body weight homeostasis is tightly regulated throughout life. With the discovery of orexigenic and anorectic signals, an array of new molecular targets to control eating behavior has emerged. This review focuses on recent advances in three important signal systems: leptin, ghrelin, and endocannabinoids toward the identification of potential therapeutical breakthroughs in AN. Our review of the current literature shows that leptin may have therapeutic potentials in promoting restoration of menstrual cycles in weight restored patients, reducing motor restlessness in severely hyperactive patients, and preventing osteoporosis in chronic patients. Ghrelin and endocannabinoids exert orexigenic effects which may facilitate nutritional restoration. Leptin and endocannabinoids may exert antidepressive and anxiolytic effects. Finally, monitoring serum concentration of leptin may be useful in order to prevent refeeding syndrome.
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Affiliation(s)
- René Klinkby Støving
- Center for Eating Disorders and Department of Endocrinology, Odense University Hospital, DK-5000 Odense, Denmark.
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Influence of intracerebroventricular or intraperitoneal administration of cannabinoid receptor agonist (WIN 55,212-2) and inverse agonist (AM 251) on the regulation of food intake and hypothalamic serotonin levels. Br J Nutr 2009; 101:1569-78. [PMID: 19245736 DOI: 10.1017/s0007114508083530] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effect of intracerebroventricular or intraperitoneal administration of cannabinoid receptor agonist WIN 55,212-2 or inverse agonist AM 251 on food intake and extracellular levels of serotonin and acetic acid 5-hydroxy-indol from presatiated rats was studied. Compared to the vehicle-injected control, the intracerebroventricular administration of WIN 55,212-2 was associated with a significant increase in food intake, whereas the administration of AM 251 caused a significant reduction in this respect. These results were accompanied by considerable reductions or increases in serotonin and acetic acid 5-hydroxy-indol levels compared to the vehicle-injected control and the baseline values for the different experimental groups studied. Intraperitoneal administration of WIN 55,212-2 at doses of 1 and 2 mg/kg promoted hyperphagia up to 6 h after injection, whereas administration of a higher dose (5 mg/kg) significantly inhibited food intake and motor behaviour in partially satiated rats. Administration of any of the AM 251 doses studied (0.5, 1, 2, 5 mg/kg) led to a significant decrease in the amount of food ingested from 2 h after the injection, compared to the vehicle-injected control group, with the most striking effect being observed when the 5 mg/kg dose was injected.
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Scheen AJ, Paquot N. Use of cannabinoid CB1 receptor antagonists for the treatment of metabolic disorders. Best Pract Res Clin Endocrinol Metab 2009; 23:103-16. [PMID: 19285264 DOI: 10.1016/j.beem.2008.09.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abdominal obesity is associated with numerous metabolic abnormalities, including insulin resistance, impaired glucose tolerance/type-2 diabetes, and atherogenic dyslipidaemia with low high-density lipoprotein (HDL) cholesterol, high triglycerides, and increased small dense low-density lipoprotein (LDL) cholesterol. A proportion of these metabolic disorders may be attributed to increased endocannabinoid activity. The selective cannabinoid 1 (CB1) receptor antagonist rimonabant has been shown to reduce body weight, waist circumference, insulin resistance, triglycerides, dense LDL, C-reactive protein (CRP), and blood pressure, and to increase HDL and adiponectin concentrations in both non-diabetic and diabetic overweight/obese patients. Besides an improvement in glucose tolerance in non-diabetic subjects, a reduction of 0.5-0.7% in haemoglobin A1C (HbA(1c)) levels was consistently observed in various groups of patients with type-2 diabetes. Almost half the metabolic changes could not be explained by weight loss, supporting direct peripheral effects of rimonabant. Ongoing studies should demonstrate whether improved metabolic disorders with CB1 receptor antagonists (rimonabant, taranabant, etc.) would translate into fewer cardiovascular complications among high-risk individuals.
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Affiliation(s)
- André J Scheen
- Division of Diabetes, Nutrition and Metabolic Disorders, Department of Medicine, CHU Sart Tilman (B35), University of Liège, B 4000 Liège, Belgium.
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Effects of rimonabant on behavior maintained by progressive ratio schedules of sucrose reinforcement in obese Zucker (fa/fa) rats. Behav Pharmacol 2008; 19:735-42. [DOI: 10.1097/fbp.0b013e3283123cc2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nieuwenhuizen AG, Rutters F. The hypothalamic-pituitary-adrenal-axis in the regulation of energy balance. Physiol Behav 2008; 94:169-77. [DOI: 10.1016/j.physbeh.2007.12.011] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 12/13/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
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Lee YM, Uhm KO, Lee ES, Kwon J, Park SH, Kim HS. AM251 suppresses the viability of HepG2 cells through the AMPK (AMP-activated protein kinase)-JNK (c-Jun N-terminal kinase)-ATF3 (activating transcription factor 3) pathway. Biochem Biophys Res Commun 2008; 370:641-5. [PMID: 18406347 DOI: 10.1016/j.bbrc.2008.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 04/02/2008] [Indexed: 12/24/2022]
Abstract
AM251, a cannabinoid antagonist, has various biological activities. In this study, we found that AM251 suppressed the viability of hepatoma HepG2 cells and also increased phosphorylation of JNK (c-jun N-terminal kinase) and ATF3 (activating transcription factor 3). In addition, AM251 phosphorylated AMPK (AMP-activated protein kinase) in a time and dose-dependent manner. Inhibition of AMPK blocked AM251-induced JNK/ATF3 phosphorylation. Expression of AMPK or treatment with AICAR (5-aminoimidazole-4-carboxy-amide-1-d-ribofuranoside), an AMPK activator, activated the JNK/ATF3 pathways. Together, these results suggest that AM251 may have anti-tumor effects in hepatoma through activation of the AMPK-JNK-ATF3 signal pathway.
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Affiliation(s)
- Yun Mi Lee
- Department of Anatomy, Korea University College of Medicine, 126-1, 5 ga, Anam-dong, Seongbuk-gu, Seoul 136-701, South Korea
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Abstract
The endocannabinoid system consists of endogenous arachidonic acid derivates that activate cannabinoid receptors. The two most prominent endocannabinoids are anandamide and 2-arachidonoyl glycerol. In obesity, increased concentrations of circulating and tissue endocannabinoid levels have been described, suggesting increased activity of the endocannabinoid system. Increased availability of endocannabinoids in obesity may over-stimulate cannabinoid receptors. Blockade of cannabinoid type 1 (CB1) receptors was the only successful clinical development of an anti-obesity drug during the last decade. Whereas blockade of CB1 receptors acutely reduces food intake, the long-term effects on metabolic regulation are more likely mediated by peripheral actions in liver, skeletal muscle, adipose tissue, and the pancreas. Lipogenic effects of CB1 receptor signalling in liver and adipose tissue may contribute to regional adipose tissue expansion and insulin resistance in the fatty liver. The association of circulating 2-arachidonoyl glycerol levels with decreased insulin sensitivity strongly suggests further exploration of the role of endocannabinoid signalling for insulin sensitivity in skeletal muscle, liver, and adipose tissue. A few studies have suggested a specific role for the regulation of adiponectin secretion from adipocytes by endocannabinoids, but that has to be confirmed by more experiments. Also, the potential role of CB1 receptor blockade for the stimulation of energy expenditure needs to be studied in the future. Despite the current discussion of safety issues of cannabinoid receptor blockade, these findings open a new and exciting perspective on endocannabinoids as regulators of body weight and metabolism.
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Affiliation(s)
- Stefan Engeli
- Franz Volhard Clinical Research Center at the Experimental and Clinical Research Center, Charité - Campus Buch, Berlin, Germany.
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Abstract
Type-2 diabetes is closely related to abdominal obesity and is generally associated with other cardiometabolic risk factors, resulting in a risk of major cardiovascular disease. Several animal and human observations suggest that the endocannabinoid system is over-active in the presence of abdominal obesity and/or diabetes. Both central and peripheral endocannabinoid actions, via the activation of CB1 receptors, promote weight gain and associated metabolic changes. Rimonabant, the first selective CB(1) receptor blocker in clinical use, has been shown to reduce body weight, waist circumference, triglycerides, blood pressure, insulin resistance index and C-reactive protein levels, and to increase high-density lipoprotein (HDL) cholesterol and adiponectin concentrations in both non-diabetic and diabetic overweight/obese patients. In addition, a 0.5-0.7% reduction in HbA1c levels was observed in metformin- or sulphonylurea-treated patients with type-2 diabetes and in drug-naïve diabetic patients. Almost half of the metabolic changes, including HbA1c reduction, could not be explained by weight loss, suggesting that there are direct peripheral effects. Rimonabant was generally well-tolerated, and the safety profile was similar in diabetic and non-diabetic patients, with a higher incidence of depressed mood disorders, nausea and dizziness. In conclusion, the potential role of rimonabant in overweight/obese patients with type-2 diabetes and at high risk of cardiovascular disease deserves much consideration.
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Affiliation(s)
- André J Scheen
- Division of Diabetes, Nutrition and Metabolic Disorders, CHU Sart Tilman (B35), University of Liege, B 4000 Liege, Belgium.
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Abstract
The endocannabinoid system elicits multiple physiologic functions that are not fully understood. Antagonism of cannabinoid type 1 (CB(1)) receptors has been the only successful new pharmacologic treatment approach in Phase III studies in obesity in the last 8 years. Whereas antagonism of (CB(1)) receptors acutely reduces food intake, the long-term effects on weight reduction and metabolic regulation appear to be mediated by stimulation of energy expenditure and by peripheral effects related to liver, skeletal muscle, adipose tissue, and pancreas physiology. For example, in the liver, lipogenic enzymes and fatty acid synthesis are upregulated by endocannabinoids, and in adipose tissue, antagonism of (CB(1)) receptors increases secretion of adiponectin. Some studies suggest that endocannabinoid formation is increased in obesity, perhaps because endocannabinoid degradation is decreased. Although many questions remain unanswered at present, the emerging concept of endocannabinoids as metabolic regulators helps to explain the success of rimonabant (SR141716), an antagonist of (CB(1)) receptors, currently in Phase III studies.
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Affiliation(s)
- Stefan Engeli
- Franz Volhard Clinical Research Center, University Clinic Charité Campus Buch, Humboldt University of Berlin, Wiltbergstrasse 50, 13125 Berlin, Germany.
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Calder PC. The British Journal of Nutrition, an international journal that continues to develop. Br J Nutr 2007. [DOI: 10.1079/bjn20061881] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Obesity is a multidisciplinary area, the ‘biology’ of which encompasses: (1) the fundamental mechanisms of energy balance and its regulation; (2) the biological basis for the development of obesity; (3) adipose tissue function; (4) the biological description of the obese state; (5) the pathological consequences of obesity; (6) the physiological basis for treatment strategies. At a mechanistic level, important developments in recent years include the identification of novel neuroendocrine factors in the control of appetite (such as cocaine- and amphetamine-regulated transcript, the orexins, the endocannabinoids) and the discovery of new peripheral signals (such as leptin, ghrelin). Despite the identification of additional uncoupling proteins (UCP2, UCP3), mitochondrial uncoupling in brown adipose tissue through UCP1 remains the only major mechanism for adaptive thermogenesis. White adipose tissue (WAT) has now moved centre stage in energy balance and obesity research, and there are three main reasons: (1) it is the organ which defines obesity; (2) it is the source of a critical endocrine signal in the control of body weight; (3) it secretes a range of diverse protein factors, termed adipokines, some of which are directly implicated in the pathologies associated with obesity. WAT is now recognised as a key endocrine organ, communicating both with the brain and peripheral tissues through the adipokines. Obesity is characterised by mild inflammation, and WAT may be the main locus of the inflammatory state, producing cytokines, chemokines, acute-phase proteins and angiogenic factors. It has been suggested that inflammation in obesity is principally an adaptive response to hypoxia in clusters of adipocytes within the expanding adipose mass.
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Affiliation(s)
- Paul Trayhurn
- Neuroendocrine & Obesity Biology Unit, Liverpool Centre for Nutritional Genomics, School of Clinical Sciences, University of Liverpool, UK.
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Beck B. Neuropeptide Y in normal eating and in genetic and dietary-induced obesity. Philos Trans R Soc Lond B Biol Sci 2007; 361:1159-85. [PMID: 16874931 PMCID: PMC1642692 DOI: 10.1098/rstb.2006.1855] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neuropeptide Y (NPY) is one the most potent orexigenic peptides found in the brain. It stimulates food intake with a preferential effect on carbohydrate intake. It decreases latency to eat, increases motivation to eat and delays satiety by augmenting meal size. The effects on feeding are mediated through at least two receptors, the Y1 and Y5 receptors. The NPY system for feeding regulation is mostly located in the hypothalamus. It is formed of the arcuate nucleus (ARC), where the peptide is synthesized, and the paraventricular (PVN), dorsomedial (DMN) and ventromedial (VMN) nuclei and perifornical area where it is active. This activity is modulated by the hindbrain and limbic structures. It is dependent on energy availability, e.g. upregulation with food deprivation or restriction, and return to baseline with refeeding. It is also sensitive to diet composition with variable effects of carbohydrates and fats. Leptin signalling and glucose sensing which are directly linked to diet type are the most important factors involved in its regulation. Absence of leptin signalling in obesity models due to gene mutation either at the receptor level, as in the Zucker rat, the Koletsky rat or the db/db mouse, or at the peptide level, as in ob/ob mouse, is associated with increased mRNA abundance, peptide content and/or release in the ARC or PVN. Other genetic obesity models, such as the Otsuka-Long-Evans-Tokushima Fatty rat, the agouti mouse or the tubby mouse, are characterized by a diminution in NPY expression in the ARC nucleus and by a significant increase in the DMN. Further studies are necessary to determine the exact role of NPY in these latter models. Long-term exposure to high-fat or high-energy palatable diets leads to the development of adiposity and is associated with a decrease in hypothalamic NPY content or expression, consistent with the existence of a counter-regulatory mechanism to diminish energy intake and limit obesity development. On the other hand, an overactive NPY system (increased mRNA expression in the ARC associated with an upregulation of the receptors) is characteristic of rats or rodent strains sensitive to dietary-induced obesity. Finally, NPY appears to play an important role in body weight and feeding regulation, and while it does not constitute the only target for drug treatment of obesity, it may nevertheless provide a useful target in conjunction with others.
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Affiliation(s)
- B Beck
- Université Henri Poincaré, Neurocal, Nancy, France.
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Trayhurn P, Bing C. Appetite and energy balance signals from adipocytes. Philos Trans R Soc Lond B Biol Sci 2007; 361:1237-49. [PMID: 16815801 PMCID: PMC1642696 DOI: 10.1098/rstb.2006.1859] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Interest in the biology of white adipose tissue has risen markedly with the recent surge in obesity and its associated disorders. The tissue is no longer viewed simply as a vehicle for lipid storage; instead, it is recognized as a major endocrine and secretory organ. White adipocytes release a multiplicity of protein hormones, signals and factors, termed adipokines, with an extensive range of physiological actions. Foremost among these various adipokines is the cytokine-like hormone, leptin, which is synthesized predominantly in white fat. Leptin plays a critical role in the control of appetite and energy balance, with mutations in the genes encoding the hormone or its receptor leading to profound obesity in both rodents and man. Leptin regulates appetite primarily through an interaction with hypothalamic neuroendocrine pathways, inhibiting orexigenic peptides such as neuropeptide Y and orexin A, and stimulating anorexigenic peptides such as proopiomelanocortin. White fat also secretes several putative appetite-related adipokines, which include interleukin-6 and adiponectin, but whether these are indeed significant signals in the regulation of food intake has not been established. Through leptin and the other adipokines it is evident that adipose tissue communicates extensively with other organs and plays a pervasive role in metabolic homeostasis.
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Affiliation(s)
- Paul Trayhurn
- Obesity Biology Unit (Liverpool Centre for Nutritional Genomics and Liverpool Obesity Research Network), School of Clinical Sciences, University of Liverpool, UK.
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Kyrou I, Valsamakis G, Tsigos C. The Endocannabinoid System as a Target for the Treatment of Visceral Obesity and Metabolic Syndrome. Ann N Y Acad Sci 2006; 1083:270-305. [PMID: 17148745 DOI: 10.1196/annals.1367.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The endogenous cannabinoid system is a novel, remarkably elaborate physiological signaling system, comprising the recently identified endogenous cannabinoid ligands, their corresponding selective receptors, and the machinery of proteins and enzymes that is involved in their biosynthesis, release, transport, and degradation. This system extends widely in both the central nervous system (CNS) and the periphery and exhibits a variety of actions implicated in vital functions (e.g., behavioral, antinociceptive, neuroprotective, immunosuppressive, cardiovascular, and metabolic). Particular interest has been focused on the apparent participation of endocannabinoids in metabolic homeostasis by modulating the activity of CNS circuits that control food intake and energy expenditure, the neuroendocrine response of the stress system, and the metabolic functions of crucial peripheral tissues, such as the adipose tissue, the gastrointestinal tract, the liver, and the skeletal muscles. These effects are predominantly CB(1) receptor mediated and, thus, selective antagonists of this receptor subtype are being vigorously investigated as potential therapeutic agents for the treatment of various metabolic derangements (e.g., obesity, insulin resistance, dyslipidemia, and metabolic syndrome). The first selective CB(1) receptor antagonist, rimonabant, has already successfully completed phase III clinical trials as adjunctive obesity treatment, with significant improvements in several associated metabolic and cardiovascular risk factors that led to the recent approval of its clinical use by the Food and Drug Administration.
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Affiliation(s)
- Ioannis Kyrou
- Endocrinology, Metabolism and Diabetes Unit, Evgenidion Hospital, Athens University Medical School, Athens 115 28, Greece
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Puri P, Sanyal AJ. Role of obesity, insulin resistance, and steatosis in hepatitis C virus infection. Clin Liver Dis 2006; 10:793-819. [PMID: 17164118 DOI: 10.1016/j.cld.2006.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatitis C, nonalcoholic fatty liver characterized by hepatic steatosis, and obesity inflict significant health and economic burdens on the Western world. Insulin resistance is the key player in these disease processes. Complex interplay between these conditions results in the ultimate phenotype of liver disease. This article focuses on the current understanding of host and viral interactions as well as on consequent clinical implications.
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Affiliation(s)
- Puneet Puri
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University Health System, 1200 East Broad Street, Richmond, VA 23298, USA
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Drug residues store in the body following cessation of use: impacts on neuroendocrine balance and behavior--use of the Hubbard sauna regimen to remove toxins and restore health. Med Hypotheses 2006; 68:868-79. [PMID: 17045758 DOI: 10.1016/j.mehy.2006.08.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Accepted: 08/21/2006] [Indexed: 11/24/2022]
Abstract
For decades, scientists have investigated the environmental and human health effects of synthetic chemicals. A growing body of research has illuminated the spectrum of consequences deriving from our reliance these substances and their proliferation in air, water, soil and the food chain. Of particular concern is the fact that residues of many man-made chemicals are now detectible in virtually every person. A key to a chemical's tendency to persist in tissues once it has entered the body is its lipophilicity. Substances that are poorly soluble in water and quite soluble in fat have relatively free access, via lipid-rich cellular membranes, to the cells of all organs including the ability to cross the blood-brain and placental barriers. Substantial data exist demonstrating that in addition to pollutants, drugs and their metabolites dispose to tissues high in fat content, including brain and adipose. While their characteristic lipophilicity permits drugs and medications to reach target tissues, thereby producing therapeutic effects in the present, current perceptions of risk may be ignoring the possibility that adipose accumulations of illicit drugs and pharmaceuticals may lead to future patterns of ill health similar to those associated with exposure to other categories of xenobiotic chemicals. Empirical data are beginning to characterize the myriad regulatory functions of adipose hormones, including roles in cravings, cognitive function, energy level, and inflammation as well as changes in adipose hormone levels associated with drug use. Included in this data are the observation that a rehabilitative treatment intervention introduced by L. Ron Hubbard in 1978 to aid in the broad elimination of chemicals from body stores improves symptoms common to both chemical exposure and drug addiction. The regimen, which includes exercise, sauna bathing, and vitamin and mineral supplementation, is utilized by nearly 70 drug rehabilitation and medical practices in over 20 countries. At present, much more is unknown than is known regarding long-term drug retention and effects. This subject deserves careful evaluation given its potential implications for health and chronic illnesses of poorly defined etiology (such as chronic fatigue syndrome), as well as drug abuse prevention, drug rehabilitation, forensic and legal areas.
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Carai MAM, Colombo G, Maccioni P, Gessa GL. Efficacy of rimonabant and other cannabinoid CB1 receptor antagonists in reducing food intake and body weight: preclinical and clinical data. CNS DRUG REVIEWS 2006; 12:91-9. [PMID: 16958983 PMCID: PMC6494144 DOI: 10.1111/j.1527-3458.2006.00091.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present paper focuses on the different lines of evidence indicating that cannabinoid CB(1) receptor antagonists, including the prototype rimonabant, reduce food intake and body weight in laboratory animals. Recent clinical surveys demonstrated that rimonabant significantly reduced body weight also in overweight/obese humans. Treatment with rimonabant was associated with a beneficial effect on different metabolic parameters and cardiovascular risk factors linked to overweight. The data reviewed in this paper suggest that cannabinoid CB(1) receptor antagonists may constitute a novel class of drugs potentially effective in the treatment of obesity-related disorders.
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Affiliation(s)
- Mauro A M Carai
- C.N.R. Institute of Neuroscience, University of Cagliari, Cagliari (CA), Italy.
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41
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Pacher P, Bátkai S, Kunos G. The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacol Rev 2006; 58:389-462. [PMID: 16968947 PMCID: PMC2241751 DOI: 10.1124/pr.58.3.2] [Citation(s) in RCA: 1458] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The recent identification of cannabinoid receptors and their endogenous lipid ligands has triggered an exponential growth of studies exploring the endocannabinoid system and its regulatory functions in health and disease. Such studies have been greatly facilitated by the introduction of selective cannabinoid receptor antagonists and inhibitors of endocannabinoid metabolism and transport, as well as mice deficient in cannabinoid receptors or the endocannabinoid-degrading enzyme fatty acid amidohydrolase. In the past decade, the endocannabinoid system has been implicated in a growing number of physiological functions, both in the central and peripheral nervous systems and in peripheral organs. More importantly, modulating the activity of the endocannabinoid system turned out to hold therapeutic promise in a wide range of disparate diseases and pathological conditions, ranging from mood and anxiety disorders, movement disorders such as Parkinson's and Huntington's disease, neuropathic pain, multiple sclerosis and spinal cord injury, to cancer, atherosclerosis, myocardial infarction, stroke, hypertension, glaucoma, obesity/metabolic syndrome, and osteoporosis, to name just a few. An impediment to the development of cannabinoid medications has been the socially unacceptable psychoactive properties of plant-derived or synthetic agonists, mediated by CB(1) receptors. However, this problem does not arise when the therapeutic aim is achieved by treatment with a CB(1) receptor antagonist, such as in obesity, and may also be absent when the action of endocannabinoids is enhanced indirectly through blocking their metabolism or transport. The use of selective CB(2) receptor agonists, which lack psychoactive properties, could represent another promising avenue for certain conditions. The abuse potential of plant-derived cannabinoids may also be limited through the use of preparations with controlled composition and the careful selection of dose and route of administration. The growing number of preclinical studies and clinical trials with compounds that modulate the endocannabinoid system will probably result in novel therapeutic approaches in a number of diseases for which current treatments do not fully address the patients' need. Here, we provide a comprehensive overview on the current state of knowledge of the endocannabinoid system as a target of pharmacotherapy.
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Affiliation(s)
- Pál Pacher
- Laboratory of Physiological Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Room 2S-24, Bethesda, MD 20892-9413, USA
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Abstract
The lack of appropriate animal models is a major limitation in research of bipolar disorder (BPD): at this time there are very few models for this devastating disease. Whereas limited attempts have been made to develop comprehensive models for BPD, the new notion of endophenotypes encourages us to explore the possibility of developing separate models for separate facets of the disorder. Since more models are available for depression, there is a dire need for models for mania that will be relatively easy and simple to induce and test and will therefore be practical for purposes of screening possible new drugs or mutant mice that are developed based on novel molecular theories. Such models may already be tentatively available as they were developed in the context of other disorders, but there is a need to validate them for mania. The present paper proposes such models for most of the facets of mania including: increased energy, activity or restlessness; extreme irritability; reduced sleep; provocative, intrusive or aggressive behaviour; increased sexual drive; abuse of drugs; distractibility, reduced ability to concentrate; and unrealistic beliefs in one's abilities and powers resulting in poor judgement. Validating these models may demand a major research effort but it may be worthy as validated models for the different facets of mania could then be used efficiently and may be utilized to construct a standard battery of tests that can serve to explore the various components of manic-like behaviour in rodents.
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Affiliation(s)
- Haim Einat
- Department of Pharmacy Practice and Pharmaceutical Research, College of Pharmacy, University of Minnesota Duluth, Duluth MN 55812, USA.
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43
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Colagiuri R, Colagiuri S, Yach D, Pramming S. The answer to diabetes prevention: science, surgery, service delivery, or social policy? Am J Public Health 2006; 96:1562-9. [PMID: 16873751 PMCID: PMC1551964 DOI: 10.2105/ajph.2005.067587] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2005] [Indexed: 01/18/2023]
Abstract
The diabetes and obesity epidemics are closely intertwined. International randomized controlled trials demonstrate that, in high-risk individuals, type 2 diabetes can be prevented or at least delayed through lifestyle modification and, to a lesser degree, medication. We explored the relative roles of science, surgery, service delivery, and social policy in preventing diabetes. Although it is clear that there is a role for all, diabetes is a complex problem that demands commitment across a range of government and nongovernment agencies to be effectively controlled. Accordingly, we argue that social policy is the key to achieving and sustaining social and physical environments required to achieve widespread reductions in both the incidence and prevalence of diabetes.
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Affiliation(s)
- Ruth Colagiuri
- Diabetes Unit, Australian Health Policy Institute, University of Sydney, Sydney, NSW, Australia.
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Rigamonti AE, Giordani C, Bonomo SM, Cella SG, Müller EE. Early tolerance to the hypophagic effect of the cannabinoid receptor antagonist SR141716 does not impede blockade of an orexigenic stimulus. Eur J Pharmacol 2006; 542:116-20. [PMID: 16806163 DOI: 10.1016/j.ejphar.2006.05.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 05/11/2006] [Accepted: 05/19/2006] [Indexed: 11/19/2022]
Abstract
The cannabinoid CB1 receptor antagonist SR141716 (Rimonabant) is known to reduce food intake by central and peripheral mechanisms. Recently, SR141716 has been reported to block the orexigenic effect of ghrelin, a potent orexigenic peptide produced by the stomach. This study investigated whether in rats, made tolerant to the hypophagic effect of SR141716, the drug was still capable to block the orexigenic activity of another non-natural (hypothalamic) peptide, i.e., the growth hormone releasing peptide (GHRP) hexarelin, a ghrelin mimetic. In the acute experiments, each dose of SR141716 (1, 5 and 10 mg/kg i.p.) reduced food intake with respect to vehicle-treated rats, whereas hexarelin (160 microg/kg s.c.) markedly stimulated feeding. All doses of SR141716 were capable to reduce the orexigenic effect of the GHRP. A 15-day administration of SR141716 (10 mg/kg i.p.) reduced both food intake and body weight. Tolerance to the hypophagic effect of SR141716 developed within 5 days, but in contrast, body weight remained markedly below that of vehicle-treated group throughout the entire treatment period. Interestingly, despite development of tolerance to its hypophagic effect, SR141716 was capable to suppress the orexigenic effect of repeated hexarelin challenge tests performed throughout the chronic experiments. In conclusion, the results of the present study confirm and broaden the existence of a functional relationship between ghrelin and endocannabinoids in the control of food intake, and bespeak the ability of a CB1 receptor antagonist to suppress orexia caused by stimuli alien to direct stimulation of the cannabinoid system.
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Affiliation(s)
- Antonello E Rigamonti
- Department of Medical Pharmacology, University of Milan, via Vanvitelli 32, 20129 Milan, Italy
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45
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Einat H. Establishment of a battery of simple models for facets of bipolar disorder: a practical approach to achieve increased validity, better screening and possible insights into endophenotypes of disease. Behav Genet 2006; 37:244-55. [PMID: 16865528 DOI: 10.1007/s10519-006-9093-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 06/15/2006] [Indexed: 12/12/2022]
Abstract
The lack of appropriate animal models for bipolar disorder (BPD) hinders the translation of novel molecular and genetic findings into the development of new more efficient treatments. Attempts to develop a comprehensive model for BPD did not result in a practical and valid model and at present most studies utilize a limited number of models for specific components of the disorder. Whereas there is a higher availability of models for the depression pole of BPD, only a few models represent the manic pole with the most frequently used being psychostimulant-induced hyperactivity. This last model had been important in studies of the disease and has some validity but it is clear that by itself cannot be considered to represent mania. Additional models for facets of BPD are needed to allow better screening of new drugs and new mutant mice. Such models may also support the exploration of endophenotypes of BPD and the mechanisms of the disease. An advantage of a battery approach is that each model can be only partially valid when used alone but the combination of a few models may result in strong validity. The present study suggests that such a battery can be based on existing models previously developed in the context of studying normal behavior or other disorders after an initial validation in the context of BPD. An example for this idea is described using the resident-intruder test for aggression. Present results show that 3 weeks oral treatment with 1.2-2.4% lithium (increasing doses), or 20 g/kg daily dose of valproate, significantly reduced aggressive behavior in resident mice without affecting non-aggressive social interactions. Accordingly, it is suggested that the simplified resident-intruder paradigm may model the aggression related to mania as part of a test battery for facets of BPD. It is further speculated that, pending further research, this paradigm can be combined with additional methods to explore changes in the LHPA axis that may be linked to an important endophenotype of BPD.
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Affiliation(s)
- Haim Einat
- College of Pharmacy, Duluth, University of Minnesota, 376 Kirby Plaza, 1208 Kirby Drive, Duluth, MN 55812, USA.
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46
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Trayhurn P, Bing C, Wood IS. Adipose tissue and adipokines--energy regulation from the human perspective. J Nutr 2006; 136:1935S-1939S. [PMID: 16772463 DOI: 10.1093/jn/136.7.1935s] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
There has been a rapid rise in the incidence of obesity, primarily as a result of changes in lifestyle (diet and activity levels). Obesity has provided considerable impetus for the investigation of the fundamental mechanisms involved in the regulation of energy balance. Important developments include the identification of novel factors involved in the control of appetite, such as ghrelin, orexin A, and the endogenous cannabinoids, and the emergence of the concept of "nonexercise activity thermogenesis" (NEAT) provided new perspectives on energy expenditure. Studies on white adipose tissue have led to the recognition that it is an important endocrine organ, communicating with the brain and peripheral tissues through the secretion of leptin and other adipokines. There is a rapidly expanding list of protein factors released by white adipose tissue, including the key hormone, adiponectin. Of particular note is the range of cytokines, chemokines, and other inflammation-related proteins secreted by white fat as tissue mass rises; indeed, obesity is characterized by chronic mild inflammation. The adipokines provide an extensive network of communication both within adipose tissue and with other organs, and some are implicated directly in the pathologies associated with obesity, particularly the metabolic syndrome. Although the focus remains very much on obesity in humans, the disorder and its sequelae are also a growing concern in companion animals.
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Affiliation(s)
- Paul Trayhurn
- Obesity Biology Unit, School of Clinical Sciences, University of Liverpool, Liverpool L69 3GA, UK.
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Gessa GL, Orrù A, Lai P, Maccioni P, Lecca R, Lobina C, Carai MAM, Colombo G. Lack of tolerance to the suppressing effect of rimonabant on chocolate intake in rats. Psychopharmacology (Berl) 2006; 185:248-54. [PMID: 16491428 DOI: 10.1007/s00213-006-0327-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Accepted: 01/03/2006] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVES Previous work indicated that tolerance to the anorectic effect of the cannabinoid CB1 receptor antagonist/inverse agonist, rimonabant, developed rather rapidly in rats and mice given access to a standard rodent chow. The present study was designed to investigate whether the reducing effect of rimonabant on intake of a highly palatable food such as a chocolate-flavoured beverage underwent a development of tolerance as rapid as that manifested on intake of a standard rodent chow. MATERIALS AND METHODS To this aim, Wistar rats were concurrently exposed, with unlimited access for 24 h/day, to the chocolate-flavoured beverage, regular food pellets and water. Rimonabant (0, 1.25, 2.5 and 5 mg/kg; i.p.) was administered once a day for 21 consecutive days. RESULTS Rimonabant administration resulted in a dose-dependent suppression of the high, daily intake of the chocolate-flavoured beverage; this effect lasted for the entire 21-day treatment period, without any apparent development of tolerance. Conversely, rimonabant-induced reduction in daily intake of regular food pellets was of a smaller magnitude and was limited to the first 3-4 days of treatment. CONCLUSIONS Together, these results indicate that chronically administered rimonabant was more effective and longer-lasting in reducing the intake of a highly palatable food than that of regular food pellets in rats. These results also suggest that rimonabant may be more active on the hedonic rather than nutritive properties of diets.
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Affiliation(s)
- Gian Luigi Gessa
- C.N.R. Institute of Neuroscience, Viale Diaz, 182, I-09126 Cagliari (CA), Italy
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48
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Hentges ST, Low MJ, Williams JT. Differential regulation of synaptic inputs by constitutively released endocannabinoids and exogenous cannabinoids. J Neurosci 2006; 25:9746-51. [PMID: 16237178 PMCID: PMC6725733 DOI: 10.1523/jneurosci.2769-05.2005] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Endocannabinoid release from a single neuron has been shown to cause presynaptic inhibition of transmitter release at many different sites. Here, we demonstrate that hypothalamic proopiomelanocortin (POMC) neurons release endocannabinoids continuously under basal conditions, unlike other release sites at which endocannabinoid production must be stimulated. The basal endocannabinoid release selectively inhibited GABA release onto POMC neurons, although exogenous administration of cannabinoid agonists also inhibited glutamate release. The CB1 cannabinoid receptor antagonist AM 251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide] blocked endocannabinoid-mediated inhibition of GABA release without affecting excitatory synaptic currents, whereas the CB1 receptor agonist WIN 55,212-2 [R-(+)-(2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]pyrol [1,2,3-de]-1,4-benzoxazin-6-yl)(1-naphthalenyl) methanone monomethanesulfonate] inhibited both inhibitory and excitatory synaptic currents in POMC neurons. These data demonstrate that endogenously released cannabinoids and exogenously applied CB1 receptor agonists can have markedly different effects on synaptic inputs. Furthermore, the data suggest a novel form of endocannabinoid-mediated retrograde inhibition, whereby the regulation of a subset of inputs requires either the removal of tonic presynaptic inhibition caused by endocannabinoids or the engagement of a mechanism that actively inhibits endocannabinoid production.
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Affiliation(s)
- Shane T Hentges
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97329, USA.
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49
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Tonstad S. Rimonabant: a cannabinoid receptor blocker for the treatment of metabolic and cardiovascular risk factors. Nutr Metab Cardiovasc Dis 2006; 16:156-162. [PMID: 16487916 DOI: 10.1016/j.numecd.2005.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
Abstract
AIMS The endocannabinoid system modulates synaptic neurotransmission centrally and peripherally and is involved in the brain pathways concerned with addiction, central regulation of body weight and adipose tissue function. The system is overactivated in animal models of obesity and nicotine use. This review discusses the role of rimonabant, a cannabinoid receptor 1 blocker, which has undergone Phase III clinical testing, in the treatment of obesity and tobacco dependence. DATA SYNTHESIS Results of Phase III clinical trials have shown that rimonabant has promising efficacy in the treatment of obesity, dyslipidaemia and diabetes associated with obesity, in preventing weight gain following smoking cessation, and possibly in smoking cessation. No critical problems with the tolerance and safety of the compound have appeared in studies to date. CONCLUSION Rimonabant may prove to be a useful aid in the treatment of the most widespread cardiometabolic risk factors.
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Affiliation(s)
- Serena Tonstad
- Department of Preventive Cardiology, Ullevål University Hospital, N-0407 Oslo, Norway.
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50
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Carpino PA, Griffith DA, Sakya S, Dow RL, Black SC, Hadcock JR, Iredale PA, Scott DO, Fichtner MW, Rose CR, Day R, Dibrino J, Butler M, Debartolo DB, Dutcher D, Gautreau D, Lizano JS, O'connor RE, Sands MA, Kelly-Sullivan D, Ward KM. New bicyclic cannabinoid receptor-1 (CB1-R) antagonists. Bioorg Med Chem Lett 2006; 16:731-6. [PMID: 16263283 DOI: 10.1016/j.bmcl.2005.10.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 10/05/2005] [Accepted: 10/06/2005] [Indexed: 11/29/2022]
Abstract
A series of conformationally constrained bicyclic derivatives derived from SR141716 was prepared and evaluated as hCB(1)-R antagonists and inverse agonists. Optimization of the structure-activity relationships around the 2,6-dihydro-pyrazolo[4,3-d]pyrimidin-7-one derivative 2a led to the identification of two compounds with oral activity in rodent feeding models (2h and 4a). Replacement of the PP group in 2h with other bicyclic groups resulted in a loss of binding affinity.
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Affiliation(s)
- Philip A Carpino
- Pfizer Global Research and Development-Groton Laboratories, Groton, CT 06340, USA.
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