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The golden spice turmeric with its main bioactive component curcumin is one of the most popular and extensively studied nutraceuticals. Despite numerous pre-clinical studies reporting positive pharmacodynamics of turmeric extracts and curcumin, the main issues in translating the pharmacological effects to clinical efficacy have been to overcome its poor pharmacokinetics and to deliver significant amounts of the biologically relevant forms of the actives to various tissues. This review is aimed at providing a first critical evaluation of the current published literature with the novel curcumagalactomannoside (CGM) formulation of curcumin using fenugreek galactomannan dietary fibre, specifically designed to address curcumin poor pharmacokinetics. We describe CGM and its technology as a food-grade formulation to deliver 'free' unconjugated curcuminoids with enhanced bioavailability and improved pharmacokinetic properties. The therapeutic relevance of improving bioavailability of 'free' curcuminoids and some of the technical challenges in the measurement of the 'free' form of curcuminoids in plasma and tissues are also discussed. A total of twenty-six manuscripts are reviewed here, including fourteen pre-clinical and twelve clinical studies that have investigated CGM pharmacokinetics, safety and efficacy in various animal models and human conditions. Overall current scientific evidence suggests CGM formulation has improved bioavailability and tissue distribution of the biologically relevant unconjugated forms of turmeric actives called 'free' curcuminoids that may be responsible for the superior clinical outcomes reported with CGM treatments in comparison with unformulated standard curcumin across multiple studies.
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OVERVIEW: A novel highly bioavailable curcumin-galactomannan (CGM) formulation was shown to have improved blood-brain-barrier (BBB) permeability of free curcuminoids in animal models; however, this has not been established in humans. The present study was conducted to determine the functional effects of CGM on brain waves in healthy individuals, owing to its BBB permeability. METHODS: A total of 18 healthy volunteers aged 35-65 were randomly assigned to consume 500 mg CGM, Unformulated curcumin (UC) or Placebo capsules twice daily for 30 days. Electroencephalogram (EEG) measurements, audio-visual reaction time tests and a working memory test were conducted at baseline and after 30 days. RESULTS: Supplementation of CGM resulted in a significant increase in α- and ß-waves (p < 0.05) as well as a significant reduction in α/ß ratio in comparison with unformulated curcumin and placebo groups. Furthermore, the CGM showed significant reduction in the audio-reaction time (29.8 %; p < 0.05) in comparison with placebo and 24.6% (p < 0.05) with unformulated curcumin. The choice-based visual-reaction time was also significantly decreased (36%) in CGM as compared to unformulated curcumin and placebo which produced 15.36% and 5.2% respectively. CONCLUSION: The observed increase in α and ß waves and reduction in α/ß ratio in the CGM group suggest that CGM can influence the brain waves in healthy subjects in a manner consistent with penetration of the blood-brain-barrier. The EEG results correlated with improved audio-visual and working memory tests which further support the role of CGM on memory improvements and fatigue reduction.
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Ondas Encefálicas , Curcumina , Administración Oral , Animales , Encéfalo , Curcumina/farmacología , Método Doble Ciego , Galactosa/análogos & derivados , Humanos , Mananos , Proyectos PilotoRESUMEN
BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is a global pandemic, and contributes significantly to the increasing incidence of conditions such as cardiovascular disease (CVD). Postprandial plasma glucose measured 2-h after the start of a meal is a good indicator of the overall status of glucose homeostasis. Clove (Syzygium aromaticum L.) and its essential oils (eugenol and acetyl eugenol) have been shown in preclinical studies to modulate pathways involved in glucose homeostasis. In addition, a water-soluble polyphenolic extract of unopened clove buds was recently shown to benefit liver function and redox status. Therefore, we conducted an open-label pilot study to test whether this polyphenolic clove extract (PCE) could influence glucose metabolism. METHODS: We evaluated the effect of PCE supplementation (250 mg once daily for 30 days) on preprandial glucose levels and 2-h postprandial glucose levels in 13 otherwise healthy volunteers who were stratified into two groups according to their initial preprandial glucose levels: Group I (n = 7) ≤100 mg/dL, Group II (n = 6) - between 101 and 125 mg/dL. In an effort to elucidate the molecular mechanisms of PCE action, we tested in vitro the effects of PCE on glucose uptake, hepatocyte glucose production, and carbohydrate hydrolyzing enzymes. RESULTS: At day 12 of supplementation, we observed statistically significant reductions in mean postprandial glucose levels in both groups [(Group I: Initial - Day 12 PPG = 13.29 mg/dL, 95% CI: 3.329-23.24) (Group II: Initial - Day 12 PPG = 16.67 mg/dL, 95% CI: 4.687-28.65, P = 0.0159)], which continued through study completion at day 30. PCE supplementation significantly decreased mean preprandial glucose levels only in Group II at Days 24 (Initial - Day 24 = 13.00 mg/dL, 95% CI: 1.407-24.59, P = 0.0345) and 30 (Initial - Day 30 = 13.67 mg/dL, 95% CI: 5.766-21.57, P = 0.0067). In cell-based assays, PCE enhanced glucose uptake in L6 myocytes and inhibited hepatocyte glucose production HepG2 cells. In cell-free assays, PCE inhibited α-amylase activity and α-glucosidase activity. CONCLUSIONS: These findings underscore the therapeutic utility of PCE for maintaining healthy glucose metabolism and warrant further larger-scale clinical trials. TRIAL REGISTRATION: This trial was retrospectively registered in the ISRCTN registry on September 29, 2018 ( ISRCTN15680985 ).
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Glucemia/efectos de los fármacos , Extractos Vegetales , Polifenoles , Estado Prediabético/tratamiento farmacológico , Syzygium , Adulto , Glucemia/análisis , Glucemia/metabolismo , Femenino , Humanos , Masculino , Proyectos Piloto , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Polifenoles/farmacología , Polifenoles/uso terapéutico , Estudios RetrospectivosRESUMEN
Obesity is a polygenic chronic condition, and dysregulation in multiple underlying energy balance processes drives the obese phenotype. Lifestyle changes can be difficult to sustain long term, and anti-obesity drugs can be an advantageous component of a successful weight loss plan. However, due to lack of efficacy or adverse safety profiles, there is currently a limited selection of anti-obesity drugs on the market. This, coupled with the notable interindividual variability in efficacy of approved treatments, represents a significant unmet medical need. In this review, we will highlight this variability in weight loss response to these existing anti-obesity compounds and discuss how underpinning genetic variation is associated with weight loss outcomes. Existing research in the field of pharmacogenomics and obesity drugs will be highlighted, as will possibilities for future focus. We will conclude by exploring examples of successful pharmacogenomics studies, and also by asking how pharmacogenomics can be built into the drug development pipeline for the benefit of patients and pharmaceutical companies alike.
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Fármacos Antiobesidad/uso terapéutico , Obesidad/tratamiento farmacológico , Obesidad/genética , Fármacos Antiobesidad/efectos adversos , Descubrimiento de Drogas , Humanos , Farmacogenética , Resultado del Tratamiento , Pérdida de Peso/efectos de los fármacosRESUMEN
New cholecystokinin-1 receptor (CCK1R) agonist 'triggers' were identified using iterative library synthesis. Structural activity relationship studies led to the discovery of compound 10e, a potent CCK1R agonist that demonstrated robust weight loss in a diet-induced obese rat model with very low systemic exposure. Pharmacokinetic data suggest that efficacy is primarily driven through activation of CCK1R's located within the intestinal wall.
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Amidas/síntesis química , Descubrimiento de Drogas , Piperidinas/síntesis química , Receptor de Colecistoquinina A/agonistas , Amidas/química , Amidas/farmacología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Concentración 50 Inhibidora , Masculino , Ratones , Ratones Obesos , Piperidinas/química , Piperidinas/farmacología , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Pérdida de Peso/efectos de los fármacosRESUMEN
Analogues related to dirlotapide (1), a gut-selective inhibitor of microsomal triglyceride transfer protein (MTP) were prepared with the goal of further reducing the potential for unwanted liver MTP inhibition and associated side-effects. Compounds were designed to decrease active metabolite load: reducing MTP activity of likely human metabolites and increasing metabolite clearance to reduce exposure. Introduction of 4'-alkyl and 4'-alkoxy substituents afforded compounds exhibiting improved therapeutic index in rats with respect to liver triglyceride accumulation and enzyme elevation. Likely human metabolites of select compounds were prepared and characterized for their potential to inhibit MTP in vivo. Based on preclinical efficacy and safety data and its potential for producing short-lived, weakly active metabolites, compound 13 (PF-02575799) advanced into phase 1 clinical studies.
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Aminoquinolinas/química , Benzamidas/química , Carbamatos/metabolismo , Proteínas Portadoras/antagonistas & inhibidores , Indoles/metabolismo , Aminoquinolinas/síntesis química , Aminoquinolinas/farmacocinética , Animales , Benzamidas/síntesis química , Benzamidas/farmacocinética , Carbamatos/síntesis química , Carbamatos/farmacocinética , Proteínas Portadoras/metabolismo , Perros , Evaluación Preclínica de Medicamentos , Humanos , Indoles/síntesis química , Indoles/farmacocinética , Microsomas Hepáticos/metabolismo , Ratas , Triglicéridos/metabolismoRESUMEN
Specialized proresolving mediators (SPMs) are endogenous lipid metabolites of long-chain polyunsaturated fatty acids that are involved in promoting the resolution of inflammation. Many disease conditions characterized by excessive inflammation have impaired or altered SPM biosynthesis, which may lead to chronic, unresolved inflammation. Exogenous administration of SPMs in infectious conditions has been shown to be effective at improving infection clearance and survival in preclinical models. SPMs have also shown tremendous promise in the context of inflammatory lung conditions, such as acute respiratory distress syndrome and chronic obstructive pulmonary disease, mostly in preclinical settings. To date, SPMs have not been studied in the context of the novel Coronavirus, severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2), however their preclinical efficacy in combatting infections and improving acute respiratory distress suggest they may be a valuable resource in the fight against Coronavirus disease-19 (COVID-19). Overall, while the research on SPMs is still evolving, they may offer a novel therapeutic option for inflammatory conditions.
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Antiinflamatorios/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Ácidos Docosahexaenoicos/uso terapéutico , Lipoxinas/uso terapéutico , Lesión Pulmonar/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , COVID-19/metabolismo , COVID-19/patología , COVID-19/virología , Herpes Simple/tratamiento farmacológico , Herpes Simple/metabolismo , Herpes Simple/patología , Humanos , Gripe Humana/tratamiento farmacológico , Gripe Humana/metabolismo , Gripe Humana/patología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , Lesión Pulmonar/metabolismo , Lesión Pulmonar/patología , Lesión Pulmonar/virología , Periodontitis/tratamiento farmacológico , Periodontitis/metabolismo , Periodontitis/patología , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/patología , Enfermedad Pulmonar Obstructiva Crónica/virología , Síndrome de Dificultad Respiratoria/metabolismo , Síndrome de Dificultad Respiratoria/patología , Síndrome de Dificultad Respiratoria/virología , SARS-CoV-2/patogenicidad , Sepsis/tratamiento farmacológico , Sepsis/metabolismo , Sepsis/patología , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/metabolismo , Tuberculosis Pulmonar/patologíaRESUMEN
We describe the design, synthesis, and structure-activity relationships of triazolobenzodiazepinone CCK1 receptor agonists. Analogs in this series demonstrate potent agonist activity as measured by in vitro and in vivo assays for CCK1 agonism. Our efforts resulted in the identification of compound 4a which significantly reduced food intake with minimal systemic exposure in rodents.
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Fármacos Antiobesidad/farmacología , Benzodiazepinas/farmacología , Receptores de Colecistoquinina/agonistas , Animales , Fármacos Antiobesidad/farmacocinética , Benzodiazepinas/química , Benzodiazepinas/farmacocinética , Masculino , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
BACKGROUND: Nocturia is the most bothersome lower urinary tract symptoms (LUTS) and can significantly reduce men's quality of life. It is often poorly managed with conventional treatments. OBJECTIVE: The purpose of this study was to evaluate the self-assessed benefits of a prostate health dietary combination formulation on mild LUTS, especially nocturia in healthy males. METHODS: In an open label clinical study, thirty healthy male subjects with mild LUTS took one daily capsule of the product for 60 days. The primary outcome was self-assessed severity of LUTS using the International Prostate Symptoms Score (IPSS) questionnaire at Day 1 (baseline), Day 30 and Day 60. Safety and compliance were also evaluated. RESULTS: At Day 60, IPSS significantly decreased from baseline by 16.3% (3.6 ± 2.1 vs. 4.3 ± 1.5, p < 0.05). Although the reduction in IPSS did not reach statistical significance at Day 30, it was mostly driven by a 30.7% decrease (p < 0.05) in the nocturia sub-score compared with baseline. While 37% of subjects reported at baseline waking up 2â3 times/night to void, none did so after taking the study product for 60 days. Compliance was very high throughout the study. No adverse events related to the study product were reported. CONCLUSIONS: The study product might be a safe alternative for individuals willing to explore a non-conventional approach to manage their nocturia. A larger randomized placebo-controlled clinical trial is warranted to confirm these results. Clinical trial registry: Clinical Trials.gov. Registration number (September 1st, 2016): NCT02886832.
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The adipocyte-derived hormone leptin plays a critical role in a variety of physiological and pathological actions. As such the determination of leptin signal transduction pathways are important both for understanding the molecular mechanisms of leptin action and for identifying sites for possible therapeutic intervention. Since the hypothalamus is the primary site of leptin action, we sought to identify a neuronal-derived human cell line containing the long form of the leptin receptor (OBRb). To this end, we screened several neuroblastoma cell lines and isolated a sub-line of SH-SY5Y cells, which we designated as SH-OBRb, for further studies. We characterized the transduction pathways induced by leptin in SH-OBRb cells and demonstrated that OBRb mediates tyrosine phosphorylation of STAT3, phosphorylation of ERK1/2, but not SAPK/JNK and p38 MAPK, in a dose and time dependent fashion. In addition, Akt appears to be phosphorylated in the basal state and to be insensitive to further activation by leptin. In summary, we have isolated a unique cell line that can be utilized as a model for use in the study of leptin action and molecular mechanisms.
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Línea Celular Tumoral , Leptina/farmacología , Neuronas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Humanos , MAP Quinasa Quinasa 4/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Neuroblastoma , Fosforilación , Factor de Transcripción STAT3/metabolismo , Tirosina/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
This pilot randomised controlled study evaluated the effects of a nutrient-supported intermittent energy restriction nutrition programme to prevent weight gain in healthy overweight adults during the 6-week winter holiday period between Thanksgiving and New Year. For 52 d, twenty-two overweight adults (mean age 41·0 years, BMI 27·3 kg/m2) were assigned to either the nutrition programme (n 10; two fasting days of 730 kcal/d (3050 kJ/d) of balanced shake and dietary supplements to support weight management efforts, followed by 5 d of habitual diet) or a control group (n 12; habitual diet). A significant weight loss from baseline (pre-holiday 10 d before Thanksgiving) to day 52 (post-holiday 3 January) was observed in the nutrition programme (75·0 (sd 9·8) v. 76·3 (sd 9·8) kg; P < 0·05). Body weight did not significantly change in the control group and there was no between-group difference. Increases from baseline in fasting insulin (42·9 %; P = 0·0256), updated homoeostasis model assessment (HOMA2) (43 %; P = 0·025), LDL-cholesterol (8·4 %; P = 0·0426) and total cholesterol (7·1 %; P = 0·0154) levels were also reported in the control group. In the nutrition programme group, baseline HDL-cholesterol and TAG levels measured after two fasting days increased (13 %; P = 0·0245) and decreased (22·8 %; P = 0·0416), respectively. There was no significant change in HOMA2. Between-group differences in changes in insulin levels (P = 0·0227), total cholesterol:HDL-cholesterol ratio (P = 0·0419) and HOMA2 (P = 0·0210) were significant. Overall compliance rate was 98 % and no severe adverse events were reported. These preliminary findings suggest that this intermittent energy restriction intervention might support weight management efforts and help promote metabolic health during the winter holiday season.
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Vacaciones y Feriados , Nutrientes , Estaciones del Año , Aumento de Peso , Adulto , Índice de Masa Corporal , Peso Corporal , Suplementos Dietéticos , Ayuno , Femenino , Humanos , Insulina , Masculino , Persona de Mediana Edad , Sobrepeso , Proyectos Piloto , Reino Unido , Pérdida de Peso , Adulto JovenRESUMEN
BACKGROUND: Sexual health positively correlates with overall wellbeing. Existing therapeutics to enhance male sexual health are limited by factors that include responsiveness, adherence and adverse effects. As the population ages, safe and effective interventions that preserve male sexual function are needed. Published research suggests that various preparations of Kaempferia parviflora, a plant in the Zingiberaceae (ginger) family, support cardiovascular health and may ameliorate erectile function. OBJECTIVE: The aim of this study was to examine the effects of KaempMax™, an ethanol extract of the K. parviflora rhizome, on erectile function in healthy middle-aged and older men. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: We conducted an open-label, one-arm study on 14 generally healthy males aged 50-68â¯years with self-reported mild erectile dysfunction, who were not using prescription treatments. Participants took 100â¯mg KaempMax™ daily for 30â¯days. MAIN OUTCOME MEASURES: Evaluations were conducted at baseline and on the final study assessment. Primary efficacy analyses included the International Index of Erectile Function (IIEF); secondary efficacy analyses included the Global Assessment Question about erectile function. RESULTS: Thirteen participants completed the 30-day study. Supplementation with KaempMax™ resulted in statistically significant improvements in erectile function, intercourse satisfaction and total scores on the IIEF questionnaire. KaempMax™ was well tolerated and exhibited an excellent safety profile. CONCLUSION: Our results suggest that KaempMax™ may improve erectile function in healthy middle-aged and older men. While the effects were not as pronounced as what might be seen with prescription medication, most participants found them satisfactory. Additional, longer and placebo-controlled clinical trials will be needed. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT03389867.
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Disfunción Eréctil/tratamiento farmacológico , Extractos Vegetales/administración & dosificación , Zingiberaceae/química , Anciano , Disfunción Eréctil/fisiopatología , Disfunción Eréctil/psicología , Humanos , Masculino , Persona de Mediana Edad , Erección Peniana/efectos de los fármacos , Proyectos Piloto , Conducta Sexual/efectos de los fármacos , Salud Sexual , Resultado del TratamientoRESUMEN
Aging is now at the forefront of major challenges faced globally, creating an immediate need for safe, widescale interventions to reduce the burden of chronic disease and extend human healthspan. Metformin and rapamycin are two FDA-approved mTOR inhibitors proposed for this purpose, exhibiting significant anti-cancer and anti-aging properties beyond their current clinical applications. However, each faces issues with approval for off-label, prophylactic use due to adverse effects. Here, we initiate an effort to identify nutraceuticals-safer, naturally-occurring compounds-that mimic the anti-aging effects of metformin and rapamycin without adverse effects. We applied several bioinformatic approaches and deep learning methods to the Library of Integrated Network-based Cellular Signatures (LINCS) dataset to map the gene- and pathway-level signatures of metformin and rapamycin and screen for matches among over 800 natural compounds. We then predicted the safety of each compound with an ensemble of deep neural network classifiers. The analysis revealed many novel candidate metformin and rapamycin mimetics, including allantoin and ginsenoside (metformin), epigallocatechin gallate and isoliquiritigenin (rapamycin), and withaferin A (both). Four relatively unexplored compounds also scored well with rapamycin. This work revealed promising candidates for future experimental validation while demonstrating the applications of powerful screening methods for this and similar endeavors.
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Suplementos Dietéticos , Descubrimiento de Drogas/métodos , Ensayos Analíticos de Alto Rendimiento , Metformina/farmacología , Imitación Molecular , Inhibidores de Proteínas Quinasas/farmacología , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Biología Computacional , Bases de Datos Genéticas , Suplementos Dietéticos/efectos adversos , Suplementos Dietéticos/clasificación , Redes Reguladoras de Genes/efectos de los fármacos , Humanos , Aprendizaje Automático , Metformina/efectos adversos , Metformina/química , Metformina/clasificación , Estructura Molecular , Terapia Molecular Dirigida , Redes Neurales de la Computación , Mapas de Interacción de Proteínas/efectos de los fármacos , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/clasificación , Transducción de Señal/efectos de los fármacos , Sirolimus/efectos adversos , Sirolimus/química , Sirolimus/clasificación , Relación Estructura-ActividadRESUMEN
Populations in developed nations throughout the world are rapidly aging, and the search for geroprotectors, or anti-aging interventions, has never been more important. Yet while hundreds of geroprotectors have extended lifespan in animal models, none have yet been approved for widespread use in humans. GeroScope is a computational tool that can aid prediction of novel geroprotectors from existing human gene expression data. GeroScope maps expression differences between samples from young and old subjects to aging-related signaling pathways, then profiles pathway activation strength (PAS) for each condition. Known substances are then screened and ranked for those most likely to target differential pathways and mimic the young signalome. Here we used GeroScope and shortlisted ten substances, all of which have lifespan-extending effects in animal models, and tested 6 of them for geroprotective effects in senescent human fibroblast cultures. PD-98059, a highly selective MEK1 inhibitor, showed both life-prolonging and rejuvenating effects. Natural compounds like N-acetyl-L-cysteine, Myricetin and Epigallocatechin gallate also improved several senescence-associated properties and were further investigated with pathway analysis. This work not only highlights several potential geroprotectors for further study, but also serves as a proof-of-concept for GeroScope, Oncofinder and other PAS-based methods in streamlining drug prediction, repurposing and personalized medicine.
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Envejecimiento/fisiología , Simulación por Computador , Longevidad/fisiología , Envejecimiento/efectos de los fármacos , Animales , Humanos , Longevidad/efectos de los fármacosRESUMEN
Orexin A has been reported to stimulate food intake in rats while orexin B does not. The purpose of this study was to determine the role of orexin A or orexin B administration on food intake in adult, male rhesus monkeys. Food intake was measured at 2 and 8 h after the morning feeding following central injections of vehicle, orexin A (10, or 20 microg) or orexin B (10, 30, or 100 microg). When compared to vehicle injections, the 10 and 20 microg doses of orexin A decreased food intake at 2 h post-dose by 45% and 64%, respectively. Eight-hour food intake was decreased at only the 20 microg orexin A dose. Orexin B at all doses and time points did not alter food intake when compared to vehicle. These results indicate that orexin A exhibits anorectic activity while orexin B does not affect food intake in the rhesus monkey.
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Conducta Alimentaria/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/administración & dosificación , Péptidos y Proteínas de Señalización Intracelular/farmacología , Macaca mulatta/fisiología , Neuropéptidos/administración & dosificación , Neuropéptidos/farmacología , Animales , Depresores del Apetito/administración & dosificación , Depresores del Apetito/farmacología , Inyecciones Intraventriculares , Masculino , OrexinasRESUMEN
An approach to the computer-assisted, pharmacophore design of nonsteroidal templates for the glucocorticoid receptor (GR) that contained an element of pseudo-C2 symmetry was developed. The enatiomer of the initial design, 1Ra, and not the designed molecule, 1S, showed the desired ligand binding to the GR. The pseudo-C2 symmetry of the template allowed for rapid improvements in GR activity resulting in potent, selective, nonsteroidal GR antagonists, CP-394531 and CP-409069.
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Fenantrenos/síntesis química , Receptores de Glucocorticoides/antagonistas & inhibidores , Unión Competitiva , Línea Celular , Humanos , Ligandos , Modelos Moleculares , Fenantrenos/química , Fenantrenos/farmacología , Ensayo de Unión Radioligante , Receptores de Glucocorticoides/agonistas , Receptores de Glucocorticoides/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , TransfecciónRESUMEN
Leptin-deficient Lep(ob)/Lep(ob)mice hypersecrete insulin in response to acetylcholine stimulation of the phospholipase C-protein kinase C (PLC-PKC) pathway, and leptin constrains this hypersecretion. Leptin has been reported to activate phosphatidylinositol 3-kinase (PI 3-K) and subsequently phosphodiesterase (PDE) to impair protein kinase A (PKA)-induced insulin secretion from cultured islets of neonatal rats. We determined if PKA-induced insulin secretion was also hyperresponsive in islets from Lep(ob)/Lep(ob)mice, and if leptin impaired this pathway in islets from these mice. Additionally, the possible role for PI 3-K and PDE in leptin-induced control of acetylcholine-induced insulin secretion was examined. Stimulation of insulin secretion with GLP-1, forskolin (an activator of adenylyl cyclase), or IBMX (an inhibitor of PDE) did not cause hypersecretion of insulin from islets of young Lep(ob)/Lep(ob)mice, and leptin did not inhibit GLP-1-induced insulin secretion from islets of these mice. Inhibition of PDE with IBMX also did not block leptin-induced inhibition of acetylcholine-mediated insulin secretion from islets of Lep(ob)/Lep(ob)mice. But, preincubation of islets with wortmannin, an inhibitor of PI 3-K activity, blocked the ability of leptin to constrain acetylcholine-induced insulin secretion from islets of Lep(ob)/Lep(ob)mice. We conclude that the capacity of the PKA pathway to stimulate insulin secretion is not increased in islets from young Lep(ob)/Lep(ob)mice, and that leptin does not regulate this pathway in islets from mice. Leptin may stimulate PI 3-K to constrain PLC-PKC-induced insulin secretion from islets of Lep(ob)/Lep(ob)mice.
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Insulina/metabolismo , Leptina/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteína Quinasa C/metabolismo , Fosfolipasas de Tipo C/metabolismo , 1-Metil-3-Isobutilxantina/farmacología , Acetilcolina/farmacología , Androstadienos/farmacología , Animales , Células Cultivadas , Colforsina/farmacología , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Glucagón/farmacología , Péptido 1 Similar al Glucagón , Secreción de Insulina , Islotes Pancreáticos/citología , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Leptina/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fragmentos de Péptidos/farmacología , Inhibidores de Fosfodiesterasa/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Precursores de Proteínas/farmacología , Transducción de Señal/fisiología , WortmaninaRESUMEN
Leptin inhibits food intake and lowers plasma insulin concentrations. This study was designed to determine whether leptin acts independent of food-intake regulation to affect meal-induced increases in plasma insulin concentrations. Leptin-deficient, Lep(ob)/Lep(ob) mice were administered 1 microg leptin intracerebroventricularly (ICV) or intraperitoneally. Food intake and plasma insulin concentrations of mice administered leptin ICV before a meal were lower, as expected, than were intakes and plasma insulin concentrations of mice administered vehicle ICV. However when food intake was controlled, meal-induced increases in plasma insulin were unaffected by ICV administration of leptin. Intraperitoneal administration of 1 microg leptin before a meal lowered meal-induced increases in plasma insulin concentrations without influencing the size of the meal. We conclude that plasma leptin concentrations can affect meal-induced insulin secretion independent of the central nervous system actions of leptin associated with food-intake regulation.
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Ingestión de Alimentos , Insulina/sangre , Leptina/administración & dosificación , Leptina/deficiencia , Animales , Femenino , Privación de Alimentos , Inyecciones Intraperitoneales , Inyecciones Intraventriculares , Leptina/genética , Leptina/fisiología , Ratones , Ratones Obesos , Factores de TiempoRESUMEN
OBJECTIVE: Obesity is a result of chronic overconsumption of calories relative to the amount of energy expended. While fat free mass can account for ~80% of the variance in energy expenditure, there is still considerable variability in energy requirements between individuals that cannot be explained. We hypothesized that responsiveness to the recently discovered myokine, irisin, which has been touted to increase energy expenditure via activation of brown adipocytes in rodents and possibly humans, may explain some of the variability in energy expenditure. MATERIALS/METHODS: Post-menopausal women (n=17) spent 24-h in a whole room indirect calorimeter. During the study day, subjects remained sedentary and consumed meals tailored to their energy requirements. Plasma irisin, leptin and adiponectin were measured in samples taken from each subject. RESULTS: Our results suggest that in general, irisin levels do not correlate with 24-h energy expenditure, however, for a subpopulation irisin levels and energy expenditure are highly correlative. CONCLUSION: Irisin may help explain some of the observed variability in individual energy requirements that cannot be accounted for by fat free mass. Therefore, interventions designed to increase irisin action may prove to be promising avenues for the treatment of obesity.
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Composición Corporal/fisiología , Metabolismo Energético/fisiología , Fibronectinas/metabolismo , Absorciometría de Fotón , Adipocitos Marrones/metabolismo , Tejido Adiposo Pardo/metabolismo , Anciano , Calorimetría Indirecta , Femenino , Humanos , Inmunoprecipitación , Leptina/metabolismo , Persona de Mediana Edad , Obesidad/metabolismoRESUMEN
We hypothesized that a combination of low doses of rimonabant and leptin would markedly reduce body weight through the modulation of neuronal activity within the hypothalamus. To this end, high fat diet-induced obese rats were randomized to receive either leptin (0.5mg/kg subcutaneously), rimonabant (3mg/kg), the combination of both, or vehicle, daily for a duration of 2 weeks. A subset of rats was pair-fed to the combination-treated animals and received either vehicle or leptin. At the end of the weight loss phase, leptin treatment was maintained for 7 days while rimonabant was discontinued to assess changes in body weight during the rebound phase. The combination of rimonabant and leptin resulted in a marked inhibition of food intake and a profound reduction in body weight that was greater than achieved with either leptin or rimonabant alone. Treatment with leptin during the rebound phase inhibited compensatory increases in body weight associated with restitution of ad libitum feeding in previously pair-fed rats. Moreover, leptin partially blunted the rebound in food intake and body weight associated with cessation of rimonabant therapy.To investigate the effect of the combination on neuronal firing in the rat hypothalamus, single unit activity was recorded from brain slices containing the ventromedial and arcuate nuclei. The combination of rimonabant and leptin synergistically increased and decreased neuronal firing in the ventromedial and arcuate nuclei, respectively. Overall, these data demonstrate profound anti-obesity effects of combining cannabinoid type 1 receptor antagonists and leptin.