RESUMO
Obesity is known as metabolic syndrome and it affects many tissues including adipose tissue, liver, and central nervous system (CVS). Gambi-jung (GBJ) is a modified prescription of Taeumjowi-tang (TJT), which has been used to treat obesity in Korea. GBJ is composed of 90% Ephedra sinica Stapf (ES). Therefore, the present study was designed to assess the antiobesity effects of GBJ and to compare the effects of GBJ and ES on obesity. GBJ administration remarkably reduced the body weight, Body mass index (BMI), and body fat percentage compared to the ES administration in human subjects. GBJ-treated mice had lower white adipose tissue (WAT) amounts than ES-treated mice. GBJ and ES administration enhanced adenosine monophosphate-activated protein kinase (AMPK) expression in 3T3-L1 adipocytes, epididymal WAT and liver of HFD-induced obese mice. Moreover, GBJ and ES reduced food intake by suppressing the mRNA levels of orexigenic peptides, agouti-related protein (AgRP) and neuropeptide-Y (NPY), as well as AMPK in the brain of HFD-induced obese mice. Furthermore, GBJ-treated mice had dramatically lower expression of macrophage marker F4/80 in epididymal WAT than those of ES-treated mice. Based on these results, we suggest the use of GBJ as a natural drug to control weight gain.
Assuntos
Fármacos Antiobesidade/uso terapêutico , Obesidade/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Células 3T3-L1 , Tecido Adiposo Branco/efeitos dos fármacos , Adulto , Idoso , Animais , Depressores do Apetite/química , Depressores do Apetite/farmacologia , Composição Corporal/efeitos dos fármacos , Índice de Massa Corporal , Ingestão de Alimentos/efeitos dos fármacos , Ephedra sinica/química , Efedrina/química , Efedrina/farmacologia , Feminino , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Redução de Peso/efeitos dos fármacosRESUMO
CART (cocaine- and amphetamine-regulated transcript) peptides are involved in food intake regulation, stress, and other physiological functions. Although CART peptides have been known for over 25 years, their receptor(s) have not yet been characterized. In this short review, we will summarize our previous studies, where we reported specific binding of 125 I-CART(61-102) to PC12 rat pheochromocytoma cells. Competitive binding experiments performed with mono- and di-iodinated peptides and their isoforms with oxidized Met67 resulted in nanomolar binding affinity. Moreover, in our previous study, CART(61-102), as well as di-iodinated CART(61-102), have shown a strong anorexigenic effect in fasted lean mice after intracerebroventricular administration. In conclusion, from our previous studies, iodination of CART(61-102) resulted in mono- and di-iodinated analogs with or without oxidized Met67 . All analogs revealed a high affinity to binding sites at PC12 cells and preserved biological activity.
Assuntos
Depressores do Apetite/farmacocinética , Proteínas do Tecido Nervoso/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Animais , Depressores do Apetite/química , Depressores do Apetite/uso terapêutico , Radioisótopos do Iodo/química , Camundongos , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/uso terapêutico , Células PC12 , Ligação Proteica , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/uso terapêutico , RatosRESUMO
Fenugreek (Trigonella foenum-graecum L.) is a native plant found in the parts of Iran to the North of India, and is presently planted also in other regions of the world. Fenugreek is considered a notable multipurpose medicinal and traditional herb in Iran, India, and China for several centuries. The most important components of fenugreek seeds are protein, neutral detergent fiber, gum, lipids, moisture, ash and starch. Fenugreek seeds and leaves are anti-cholesterolemic, anti-tumor, antiinflammatory, carminative, demulcent, deobstruent, emollient, expectorant, galactogogue, febrifuge, laxative, hypoglycaemic, restorative, parasiticide and uterine tonic and useful in burning sensation. Traditionally, fenugreek seeds being used worldwide are beneficial for bone and muscles, respiratory system, gastro-intestinal system, female reproductive system, cardio-vascular system, endocrinology and hepatic. Fenugreek helps reduce cholesterol, reduce cardiovascular risk, control diabetes, a good consolation for sore throats, a remedy for acid reflux, constipation, colon cancer prevention, appropriate for kidney trouble, skin infection, increase milk production, reduce menstrual discomfort, and reduce menopause symptoms. It is also an appetite suppressant that helps in weight loss. Both modern science and traditional medicine integration with novel technologies and discoveries will secure the cultivation of medicinal herbs and promote sustainability in the long-term and a wide-range.
Assuntos
Medicina Tradicional/história , Extratos Vegetais/química , Trigonella/química , Depressores do Apetite/química , Depressores do Apetite/isolamento & purificação , Depressores do Apetite/farmacologia , Doenças Cardiovasculares/prevenção & controle , História Antiga , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Sementes/química , Sementes/metabolismo , Trigonella/metabolismo , Redução de Peso/efeitos dos fármacosRESUMO
The ability of smoking to reduce body weight serves as motivation for continued smoking. It is unclear to what extent non-nicotine constituents in cigarettes are contributing to the weight-reducing effect of smoking. The purpose of the current study was to examine the effects of nicotine and four minor tobacco alkaloids (nornicotine, cotinine, anatabine, and anabasine) on food intake, one of the key regulators of body weight. In addition, a smokeless tobacco extract (STE) and e-cigarette (EC) refill liquid were used to model the effects of actual tobacco product exposure on food intake. Male Holztman rats were trained to lever press for food pellets during daily 2h sessions in operant chambers. In Experiment 1, the effects of subcutaneous injections of saline, nicotine (0.25-1.00mg/kg), nornicotine (0.50-6.00mg/kg), cotinine (1.00-100.00mg/kg), anatabine (0.25-3.00mg/kg), and anabasine (0.50-4.00mg/kg) were assessed. In Experiment 2, rats from Experiment 1 were used to examine the effects of nicotine, STE, and EC liquid. All alkaloids, except cotinine, produced a dose-dependent reduction in overall food intake. The highest doses of all drugs significantly reduced latency and response rate to obtain the first pellet. At some doses, nicotine, anatabine, and nornicotine reduced food intake within the first 45min without compensatory increases in intake later in the session. STE and EC liquid produced dose dependent decreases in food intake similar to nicotine alone. These data suggest that minor tobacco alkaloids have appetite suppressant effects and warrant further investigation into their effects on body weight, energy intake, and energy expenditure under free-feeding conditions. However, findings with STE and EC liquid suggest that nicotine is the primary constituent in these products to affect food intake, whereas levels of minor alkaloids in these products may be too low to influence food intake.
Assuntos
Alcaloides/farmacologia , Depressores do Apetite/química , Depressores do Apetite/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Nicotiana/química , Nicotina/análogos & derivados , Nicotina/farmacologia , Produtos do Tabaco , Alcaloides/administração & dosagem , Alcaloides/isolamento & purificação , Animais , Condicionamento Operante , Relação Dose-Resposta a Droga , Sistemas Eletrônicos de Liberação de Nicotina , Privação de Alimentos , Masculino , Ratos , Ratos Sprague-Dawley , Tabaco sem FumaçaRESUMO
BACKGROUND: Metabolic disorders comprise a set of different disorders varying from epidemic diseases such as diabetes mellitus to inborn metabolic orphan diseases such as phenylketonuria. Despite considerable evidence showing the importance of the computational methods in discovery and development of new pharmaceuticals, there are no systematic reviews outlining how they are utilized in the field of metabolic disorders. This review aims to discuss the necessity of the development of web-based tools and databases by integration of available information for solving Big Data problems in network pharmacology of metabolic disorders. METHODS: We undertook a structured search of bibliographic databases for peer-reviewed research literature using a focused review question and inclusion/exclusion criteria. The quality of retrieved papers was appraised using standard tools. RESULTS: The alterations in metabolic pathways cause various cardiovascular, hematological, neurological, gastrointestinal, immune disorders and cancer. In this regard, informatics, Big Data and modeling techniques aid in the design of novel therapeutic agents for metabolic diseases by addressing various Big Data problems in the network polypharmacology (drugs/pharmaceutical agents, proteins, genes, diseases, bioassays, ADMET and metabolic pathways), identification of privileged scaffolds, developing new diagnostic biomarkers, understanding the pathophysiology of disease and progress in personalized medicine. CONCLUSION: The recent advances of developing pharmaceutical agents for various metabolic disorders by considering their pathogenesis, mechanisms of action, therapeutic and adverse effects have been summarized. We have highlighted the role of computational techniques, drug repurposing, and network-based polypharmacological approaches in the identification of new/existing medicines with improved drug-likeness properties for the rare metabolic disorders.
Assuntos
Descoberta de Drogas , Doenças Metabólicas/tratamento farmacológico , Depressores do Apetite/química , Depressores do Apetite/uso terapêutico , Biologia Computacional , Reposicionamento de Medicamentos , Dislipidemias/tratamento farmacológico , Dislipidemias/patologia , Humanos , Hipolipemiantes/uso terapêutico , Doenças Metabólicas/patologia , Erros Inatos do Metabolismo/tratamento farmacológico , Erros Inatos do Metabolismo/patologia , Obesidade/tratamento farmacológico , Obesidade/patologiaRESUMO
Neuromedin U (NMU) mediates various physiological functions via NMUR1 and NMUR2 receptors. NMUR2 has been considered a promising treatment option for diabetes and obesity. Although NMU-8, a shorter peptide, has potent agonist activity for both receptors, it is metabolically unstable. Therefore, NMU-8 analogs modified with long-chain alkyl moieties via a linker were synthesized. An octadecanoyl analog (17) with amino acid substitutions [αMePhe19, Nle21, and Arg(Me)24] and a linker [Tra-γGlu-PEG(2)] dramatically increased NMUR2 selectivity, with retention of high agonist activity. Subcutaneous administration of 17 induced anorectic activity in C57BL/6J mice. Owing to its high metabolic stability, 17 would be useful in clarifying the physiological role and therapeutic application of NMU.
Assuntos
Depressores do Apetite/metabolismo , Peptídeos/metabolismo , Receptores de Neurotransmissores/metabolismo , Alquilação , Sequência de Aminoácidos , Animais , Depressores do Apetite/química , Depressores do Apetite/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/agonistas , Receptores de Neurotransmissores/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
Caralluma fimbriata Wall. is currently used as a "natural slimming" food supplement, likely due to its content in pregnane glycosides. In the present study, a commercially available Caralluma fimbriata extract (Slimaluma®; CFE, 100 mg/kg) has been evaluated for its ability to affect the ingestive behaviour in female rats, also with reference to the modulation of the brain neuropeptides NPY and ORX.The interference of CFE with α-amylase and lipase enzymes has been investigated in vitro, as possible peripheral mechanism of action. Also, the chemical composition of CFE has been assessed by NMR and spectrophotometric analysis. Results from in vivo study showed that CFE induced effects neither on blood parameters, nor on liver and gut histomorphology. Interestingly, a reduction in body weight gain with an increase in water intake and hypothalamic levels of NPY and ORX peptides were found. Phytochemical analysis, showed CFE contained about 12% of pregnane glycosides and 1.3% of polyphenols. Present results suggest possible effects of C. fimbriata on ingestive behaviour, likely mediated by central and peripheral mechanisms.
Assuntos
Apocynaceae/química , Depressores do Apetite/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Animais , Depressores do Apetite/química , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Compostos Fitoquímicos/química , Extratos Vegetais/química , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
Corticosterone plays an important role in feeding behavior. However, its mechanism remains unclear. Therefore, the present study aimed to investigate the effect of corticosterone on feeding behavior. In this study, cumulative food intake was increased by acute corticosterone administration in a dose-dependent manner. Administration of the 5-HT2c receptor agonist m-chlorophenylpiperazin (mCPP) reversed the effect of corticosterone on food intake. The anorectic effects of mCPP were also blocked by the 5-HT2c receptor antagonist RS102221 in corticosterone-treated mice. Both corticosterone and mCPP increased c-Fos expression in hypothalamic nuclei, but not the nucleus of the solitary tract. RS102221 inhibited c-Fos expression induced by mCPP, but not corticosterone. In addition, mCPP had little effect on TH and POMC levels in the hypothalamus. Furthermore, mCPP antagonized decreasing effect of the leptin produced by corticosterone. Taken together, our findings suggest that 5-HT2c receptors and leptin may be involved in the effects of corticosterone-induced hyperphagia.
Assuntos
Regulação do Apetite/efeitos dos fármacos , Corticosterona/farmacologia , Hipotálamo/efeitos dos fármacos , Leptina/agonistas , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Receptor 5-HT2C de Serotonina/metabolismo , Animais , Depressores do Apetite/química , Depressores do Apetite/farmacologia , Estimulantes do Apetite/administração & dosagem , Estimulantes do Apetite/agonistas , Estimulantes do Apetite/antagonistas & inibidores , Estimulantes do Apetite/farmacologia , Comportamento Animal/efeitos dos fármacos , Corticosterona/administração & dosagem , Corticosterona/agonistas , Corticosterona/antagonistas & inibidores , Relação Dose-Resposta a Droga , Ingestão de Energia/efeitos dos fármacos , Hiperfagia/sangue , Hiperfagia/induzido quimicamente , Hiperfagia/metabolismo , Hiperfagia/patologia , Hipotálamo/metabolismo , Hipotálamo/patologia , Leptina/antagonistas & inibidores , Leptina/sangue , Leptina/metabolismo , Camundongos Endogâmicos ICR , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Neurônios/patologia , Especificidade de Órgãos , Piperazinas/antagonistas & inibidores , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-fos/agonistas , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptor 5-HT2C de Serotonina/química , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina/farmacologia , Compostos de Espiro/farmacologia , Sulfonamidas/farmacologia , Regulação para Cima/efeitos dos fármacosRESUMO
Body weight loss of Lep(ob/ob) mice in response to leptin is larger than expected from the reduction in energy intake alone, suggesting a thermogenic action of unknown magnitude. We exploited the superior pharmacological properties of a novel long-acting leptin prepared via PASylation to study the contribution of its anorexigenic and thermogenic effects. PASylation, the genetic fusion of leptin with a conformationally disordered polypeptide comprising 600 Pro/Ala/Ser (PAS) residues, provides a superior way to increase the hydrodynamic volume of the fusion protein, thus retarding kidney filtration and extending plasma half-life. Here a single PAS(600)-leptin injection (300 pmol/g) resulted in a maximal weight reduction of 21% 6 days after application. The negative energy balance of 300 kJ/(4 d) was driven by a decrease in energy intake, whereas energy expenditure remained stable. Mice that were food restricted to the same extent showed an energy deficit of only 220 kJ/(4 d) owing to recurring torpor bouts. Therefore, the anorexigenic effect of PAS(600)-leptin contributes 75% to weight loss, whereas the thermogenic action accounts for 25% by preventing hypometabolism. In a second experiment, just four injections of PAS(600)-leptin (100 pmol/g) administered in 5- to 6-day intervals rectified the Lep(ob/ob) phenotype. In total, 16 nmol of PAS(600)-leptin per mouse triggered a weight loss of 43% within 20 days and normalized hypothermia and glucose homeostasis as well as hepatic steatosis. The beneficial properties of PAS(600)-leptin are substantiated by a comparison with previous studies in which approximately 400 nmol (â¼25-fold) unmodified leptin was mandatory to achieve similar improvements.
Assuntos
Depressores do Apetite/uso terapêutico , Metabolismo Energético/efeitos dos fármacos , Leptina/análogos & derivados , Obesidade/tratamento farmacológico , Proteínas Recombinantes de Fusão/uso terapêutico , Resposta de Saciedade/efeitos dos fármacos , Motivos de Aminoácidos , Animais , Depressores do Apetite/administração & dosagem , Depressores do Apetite/efeitos adversos , Depressores do Apetite/química , Relação Dose-Resposta a Droga , Ingestão de Energia/efeitos dos fármacos , Feminino , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Hipotálamo/patologia , Injeções Subcutâneas , Leptina/administração & dosagem , Leptina/genética , Leptina/uso terapêutico , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Mutantes , Peso Molecular , Atividade Motora/efeitos dos fármacos , Obesidade/metabolismo , Obesidade/patologia , Peptídeos/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos , Proteínas Recombinantes de Fusão/química , Organismos Livres de Patógenos Específicos , Termogênese/efeitos dos fármacos , Redução de Peso/efeitos dos fármacosRESUMO
We hypothesized that a digestion-resistant maltodextrin, Fibersol-2 (Archer Daniels Midland/Matsutani LLC, Decatur, IL, USA) may impact satiety by decreasing hunger, prolonging satiation, and/or increasing peripheral satiety signals. In a randomized, double-blind, placebo-controlled crossover study, healthy subjects (9 men and 10 women) underwent 3 treatments in which they consumed a standardized meal with a tea containing 0, 5, or 10 g of Fibersol-2. A visual analog scale questionnaire was given in 30-minute intervals to measure subjective appetite and satiety. Blood was drawn just before the meal (time 0) and at 30, 60, 90, 120, 180, and 240 minutes after meal for measurements of plasma ghrelin, cholecystokinin, gastrin, peptide YY, gastric inhibitory polypeptide, and glucagon-like peptide-1, all by enzyme-linked immunosorbent assay. There were significant delays in hunger and increased satiety for 1.5 to 2 hours after treatment with 10 g of Fibersol-2. These delays did not occur after ingesting 0 or 5 g Fibersol-2 at any time. Control and 5 g Fibersol-2 treatments did not suppress increases in hunger postmeal; hunger scores increased and satiety scores decreased significantly (P < .05) at all time points relative to the first postmeal assessment. Plasma peptide YY and glucagon-like peptide-1 were significantly increased by the ingestion of meal with tea containing 10 g Fibersol-2 compared with 0 or 5 g Fibersol-2 (P < .05). This study demonstrated that 10 g Fibersol-2 with a meal stimulated production of satiety hormones and enhanced satiety.
Assuntos
Depressores do Apetite/uso terapêutico , Peptídeo 1 Semelhante ao Glucagon/agonistas , Sobrepeso/dietoterapia , Peptídeo YY/agonistas , Polissacarídeos/uso terapêutico , Prebióticos , Resposta de Saciedade , Adulto , Depressores do Apetite/administração & dosagem , Depressores do Apetite/química , Índice de Massa Corporal , Estudos Cross-Over , Método Duplo-Cego , Células Enteroendócrinas/metabolismo , Feminino , Peptídeo 1 Semelhante ao Glucagon/sangue , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humanos , Almoço , Masculino , Pessoa de Meia-Idade , Sobrepeso/sangue , Sobrepeso/metabolismo , Peptídeo YY/sangue , Peptídeo YY/metabolismo , Polissacarídeos/administração & dosagem , Polissacarídeos/química , Prebióticos/administração & dosagem , Solubilidade , Chá , Viscosidade , Adulto JovemRESUMO
BACKGROUND: The formation of amyloid fibrils is associated with many age-related degenerative diseases. Nevertheless, the molecular mechanism that directs the nucleation of these fibrils is not fully understood. METHODS: Here, we performed MD simulations for the NFGAILS motif of hIAPP associated with the type II diabetes to estimate the stabilities of hIAPP22-28 protofibrils with different sizes: from 2 to 16 chains. In addition, to study the initial self-assembly stage, 4 and 8 IAPP22-28 chains in explicit solvent were also simulated. RESULTS: Our results indicate that the ordered protofibrils with no more than 16 hIAPP22-28 chains will be structurally stable in two layers, while one-layer or three-layer models are not stable as expected. Furthermore, the oligomerization simulations show that the initial coil structures of peptides can quickly aggregate and convert to partially ordered ß-sheet-rich oligomers. CONCLUSIONS: Based on the obtained results, we found that the stability of an IAPP22-28 oligomer was not only related with its size but also with its morphology. The driving forces to form and stabilize an oligomer are the hydrophobic effects and backbone H-bond interaction. Our simulations also indicate that IAPP22-28 peptides tend to form an antiparallel strand orientation within the sheet. GENERAL SIGNIFICANCE: Our finding can not only enhance the understanding about potential mechanisms of hIAPP nuclei formation and the extensive structural polymorphisms of oligomers, but also provide valuable information to develop potential ß-sheet formation inhibitors against type II diabetes.
Assuntos
Amiloide/química , Depressores do Apetite/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Simulação de Dinâmica Molecular , Humanos , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Estabilidade Proteica , Estrutura Secundária de ProteínaRESUMO
Bioactive peptides obtained from marine species and marine by-products are showing these days a great interest in nutraceutical and pharmaceutical applications due to their wide range of biological activities. This mini-review focuses on the potential of marine peptides to be used as appetite suppressive molecules in the prevention and/or in the treatment of obesity syndrome. An important and promising aspect in the fight against obesity is the study of anorexigenic gut hormones, like cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1), that are synthetized by enteroendocrine cells in the presence of nutrients in the gastrointestinal tract. Recent works which have focused on the interaction between marine peptides and CCK and GLP-1 are here reviewed.
Assuntos
Depressores do Apetite , Organismos Aquáticos/química , Colecistocinina/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeos , Animais , Depressores do Apetite/química , Depressores do Apetite/metabolismo , Humanos , Peptídeos/química , Peptídeos/metabolismoRESUMO
C75 is a synthetic compound described as having antitumoral properties. It produces hypophagia and weight loss in rodents, limiting its use in cancer therapy but identifying it as a potential anti-obesity drug. C75 is a fatty acid synthase (FAS) inhibitor and, through its coenzyme A (CoA) derivative, it acts as a carnitine palmitoyltransferase (CPT) 1 inhibitor. Racemic mixtures of C75 have been used in all the previous studies; however, the potential different biological activities of C75 enantiomers have not been examined yet. To address this question we synthesized the two C75 enantiomers separately. Our results showed that (-)-C75 inhibits FAS activity in vitro and has a cytotoxic effect on tumor cell lines, without affecting food consumption. (+)-C75 inhibits CPT1 and its administration produces anorexia, suggesting that central inhibition of CPT1 is essential for the anorectic effect of C75. The differential activity of C75 enantiomers may lead to the development of potential new specific drugs for cancer and obesity.
Assuntos
4-Butirolactona/análogos & derivados , Antineoplásicos/farmacologia , Depressores do Apetite/farmacologia , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Animais , Antineoplásicos/química , Depressores do Apetite/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização por Electrospray , EstereoisomerismoRESUMO
The CART (cocaine- and amphetamine-regulated transcript) peptide is an anorexigenic neuropeptide that acts in the hypothalamus. The receptor and the mechanism of action of this peptide are still unknown. In our previous study, we showed that the CART peptide binds specifically to PC12 rat pheochromocytoma cells in both the native and differentiated into neuronal phenotype. Two biologically active forms, CART(55-102) and CART(61-102), with equal biological activity, contain three disulfide bridges. To clarify the importance of each of these disulfide bridges in maintaining the biological activity of CART(61-102), an Ala scan at particular S-S bridges forming cysteines was performed, and analogs with only one or two disulfide bridges were synthesized. In this study, a stabilized CART(61-102) analog with norleucine instead of methionine at position 67 was also prepared and was found to bind to PC12 cells with an anorexigenic potency similar to that of CART(61-102). The binding study revealed that out of all analogs tested, [Ala(68,86)]CART(61-102), which contains two disulfide bridges (positions 74-94 and 88-101), preserved a high affinity to both native PC12 cells and those that had been differentiated into neurons. In food intake and behavioral tests with mice after intracerebroventricular administration, this analog showed strong and long-lasting anorexigenic potency. Therefore, the disulfide bridge between cysteines 68 and 86 in CART(61-102) can be omitted without a loss of biological activity, but the preservation of two other disulfide bridges and the full-length peptide are essential for biological activity.
Assuntos
Depressores do Apetite/farmacologia , Cistina/química , Proteínas do Tecido Nervoso/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Depressores do Apetite/química , Ligação Competitiva , Ingestão de Alimentos/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/química , Nociceptividade/efeitos dos fármacos , Células PC12 , Fragmentos de Peptídeos/química , RatosRESUMO
Long-chain fatty acids have been shown to suppress appetite and reduce energy intake (EI) by stimulating the release of gastrointestinal hormones such as cholecystokinin (CCK). The effect of NEFA acyl chain length on these parameters is not comprehensively understood. An in vitro screen tested the capacity of individual NEFA (C12 to C22) to trigger CCK release. There was a gradient in CCK release with increasing chain length. DHA (C22) stimulated significantly (P < 0.01) more CCK release than all other NEFA tested. Subsequently, we conducted a randomised, controlled, crossover intervention study using healthy males (n 18). The effects of no treatment (NT) and oral doses of emulsified DHA-rich (DHA) and oleic acid (OA)-rich oils were compared using 24 h EI as the primary endpoint. Participants reported significantly (P = 0.039) lower total daily EI (29 % reduction) with DHA compared to NT. There were no differences between DHA compared to OA and OA compared to NT. There was no between-treatment difference in the time to, or EI of, the first post-intervention eating occasion. It is concluded that NEFA stimulate CCK release in a chain length-dependent manner up to C22. These effects may be extended to the in vivo setting, as a DHA-based emulsion significantly reduced short-term EI.
Assuntos
Depressores do Apetite/metabolismo , Colecistocinina/metabolismo , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/metabolismo , Ingestão de Energia , Células Enteroendócrinas/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Adulto , Depressores do Apetite/química , Linhagem Celular Tumoral , Estudos Cross-Over , Ácidos Docosa-Hexaenoicos/química , Emulsões , Ácidos Graxos não Esterificados/química , Humanos , Masculino , Pessoa de Meia-Idade , Peso Molecular , Método Simples-Cego , Adulto JovemRESUMO
Since its discovery the therapeutic use of the pancreatic hormone amylin has been limited due to its poor water solubility and propensity for amyloid aggregation. We have entrapped the human amylin protein in polymeric nanoparticles, using a single emulsion-solvent evaporation method and investigated its effectiveness in the controlled release of the peptide. Typical preparations composed of poly-ε-caprolactone had a mean particle size of approximately 200 nm, low polydispersity index, high protein entrapment efficiency (80%) and process yield (90%), and spherical and smooth surfaces. These nanoparticles presented a controlled release in vitro for approximately 240 h. Pharmacological evaluation in vivo by subcutaneous administration in fasting mice demonstrated the bioactivity and effectiveness of the released human amylin, resulting in reduced glycemia lasting for at least 36 h. These features indicate the potential for the use of a confined particulate system in the therapeutic controlled and sustained release of human amylin.
Assuntos
Depressores do Apetite/farmacocinética , Preparações de Ação Retardada/síntese química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/farmacocinética , Nanopartículas/química , Poliésteres/química , Animais , Depressores do Apetite/administração & dosagem , Depressores do Apetite/química , Glicemia/análise , Glicemia/efeitos dos fármacos , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Composição de Medicamentos , Emulsões , Jejum , Humanos , Injeções Subcutâneas , Polipeptídeo Amiloide das Ilhotas Pancreáticas/administração & dosagem , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Tamanho da Partícula , SolubilidadeRESUMO
Hoodia gordonii extract consists of a mixture of steroid glycosides, fatty acids, plant sterols and alcohols. As part of the overall safety assessment H. gordonii extract was assessed for genotoxicity in two assays in vitro: a bacterial mutation assay; and a gene mutation assay using mouse lymphoma cells. H. gordonii extract showed no evidence of genotoxic activity in either of these assays. In addition, H. gordonii extract was assessed for mutagenic activity in a bone marrow micronucleus (MN) assay in the mouse, with 400mg/kg selected as the high-dose group, based on observations in a dose-range-finding study. The group mean frequencies of micronucleated polychromatic erythrocytes of treated animals were similar to those of the vehicle control group, indicating H. gordonii extract to be non-genotoxic under the conditions of this test. All assays were performed in compliance with the Good Laboratory Practice Regulations and in accordance with standard guidelines for genotoxicity tests. H. gordonii extract was shown to be non-genotoxic in 3 independent assays (a bacterial mutation test, a gene mutation assay using mouse lymphoma cells and a bone marrow micronucleus assay in the mouse).
Assuntos
Apocynaceae/química , Depressores do Apetite/toxicidade , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade , Extratos Vegetais/toxicidade , Animais , Depressores do Apetite/química , Depressores do Apetite/classificação , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/patologia , Linhagem Celular Tumoral , Suplementos Nutricionais , Feminino , Leucemia L5178 , Linfoma/tratamento farmacológico , Linfoma/genética , Masculino , Camundongos , Camundongos Endogâmicos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Mutagênicos/química , Mutagênicos/classificação , Mutação/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/classificação , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genéticaRESUMO
BACKGROUND: The purpose of this study was to produce triacylglycerols (TAGs) enriched in pinolenic acid (PLA) at the sn-2 position using the principle of acyl migration, from the pine nut oil containing PLA esterified exclusively at the sn-3 position. RESULTS: Two types of lipase-catalysed reactions, i.e. redistribution and reesterification of fatty acids, were successively performed using seven commercially available lipases as biocatalysts. Of the lipases tested, Novozym 435 and Lipozyme TL IM were effective biocatalysts for positioning PLA at the sn-2 location. These biocatalysts were selected for further evaluation of the effects of reaction parameters, such as temperature and water content on the migration of PLA residues to the sn-2 position and TAG content. For both lipases, a significant decrease in TAG content was observed after the lipase-catalysed redistribution of fatty acids for both lipases. The reduced TAG content could be enhanced up to approx. 92%, through lipase-catalysed re-esterification of the hydrolysed fatty acids under vacuum. CONCLUSION: TAG enriched in PLA at the sn-2 position was synthesised from pine nut oil via lipase-catalysed redistribution and re-esterification of fatty acid residues using Lipozyme TL IM and Novozym 435 as biocatalysts.
Assuntos
Proteínas Fúngicas/metabolismo , Ácidos Linolênicos/metabolismo , Lipase/metabolismo , Pinus/química , Óleos de Plantas/química , Triglicerídeos/metabolismo , Depressores do Apetite/análise , Depressores do Apetite/química , Depressores do Apetite/metabolismo , Proteínas de Bactérias/metabolismo , Suplementos Nutricionais/análise , Enzimas Imobilizadas/metabolismo , Esterificação , Ácidos Graxos/análise , Temperatura Alta , Hipolipemiantes/análise , Hipolipemiantes/química , Hipolipemiantes/metabolismo , Isomerismo , Ácidos Linolênicos/análise , Nozes/química , Óleos de Plantas/metabolismo , Sementes/química , Triglicerídeos/análise , Triglicerídeos/química , VácuoAssuntos
Depressores do Apetite/farmacologia , Receptores de Canais Iônicos de Abertura Ativada por Ligante com Alça de Cisteína/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Ativação do Canal Iônico/efeitos dos fármacos , Oxirredutases do Álcool , Animais , Depressores do Apetite/química , Encéfalo/citologia , Encéfalo/metabolismo , Fenômenos Eletrofisiológicos , Regulação da Expressão Gênica/fisiologia , Engenharia Genética , Camundongos , Modelos Moleculares , Neurônios/fisiologia , Neurotransmissores/metabolismo , Conformação ProteicaRESUMO
BACKGROUND AND PURPOSE: Rimonabant (Acomplia, SR141716A), a cannabinoid CB1 receptor inverse agonist, has recently been approved for the treatment of obesity. There are, however, concerns regarding its side effect profile. Developing a CB1 antagonist with a different pharmacological mechanism may lead to a safer alternative. To this end we have screened a proprietary small molecule library and have discovered a novel class of allosteric antagonist at CB1 receptors. Herein, we have characterized an optimized prototypical molecule, PSNCBAM-1, and its hypophagic effects in vivo. EXPERIMENTAL APPROACH: A CB1 yeast reporter assay was used as a primary screen. PSNCBAM-1 was additionally characterized in [35S]-GTPgammaS, cAMP and radioligand binding assays. An acute rat feeding model was used to evaluate its effects on food intake and body weight in vivo. KEY RESULTS: In CB1 receptor yeast reporter assays, PSNCBAM-1 blocked the effects induced by agonists such as CP55,940, WIN55212-2, anandamide (AEA) or 2-arachidonoyl glycerol (2-AG). The antagonist characteristics of PSNCBAM-1 were confirmed in [35S]-GTPgammaS binding and cAMP assays and was shown to be non-competitive by Schild analyses. PSNCBAM-1 did not affect CB2 receptors. In radioligand binding assays, PSNCBAM-1 increased the binding of [3H]CP55,940 despite its antagonist effects. In an acute rat feeding model, PSNCBAM-1 decreased food intake and body weight. CONCLUSIONS AND IMPLICATIONS: PSNCBAM-1 exerted its effects through selective allosteric modulation of the CB1 receptor. The acute effects on food intake and body weight induced in rats provide a first report of in vivo activity for an allosteric CB1 receptor antagonist.