Ginkgo biloba Extract (GbE) Stimulates the Hypothalamic Serotonergic System and Attenuates Obesity in Ovariectomized Rats

Menopause is associated with increased risk to develop obesity but the mechanisms involved are not fully understood. We have shown that Ginkgo biloba extract (GbE) improved diet-induced obesity. Since GbE might be effective in the treatment of obesity related to menopause, avoiding the side effects of hormone replacement therapy, we investigated the effect of GbE on hypothalamic systems controlling energy homeostasis. Wistar rats were either ovariectomized (OVX) or Sham-operated. After 2 months, either 500 mg.kg(-1) of GbE or vehicle were administered daily by gavage for 14 days. A subset of animals received an intracerebroventricular (i.c.v.) injection of serotonin (300 mu g) or vehicle and food intake was measured after 12 and 24 h. Another subset was submitted to in vivo microdialysis and 5-HT levels of the medial hypothalamus were measured by high performance liquid chromatography, before and up to 2 h after the administration of 500 mg.kg(-1) of GbE. Additional animals were used for quantification of 5-HT1A, 5-HT1B, 5-HT2C, 5-HTT, and pro-opiomelanocortin hypothalamic protein levels by Western blotting. OVX increased food intake and body weight and adiposity while GbE attenuated these alterations. i.c.v. serotonin significantly reduced food intake in Sham, Sham + GbE, and OVX + GbE groups while it failed to do so in the OVX group. In the OVX rats, GbE stimulated 5-HT microdialysate levels while it reduced hypothalamic 5-HTT protein levels. The results indicate that GbE improved the ovariectomy-induced resistance to serotonin hypophagia, at least in part through stimulation of the hypothalamic serotonergic activity. Since body weight gain is one of the most important consequences of menopause, the stimulation of the serotonergic transmission by GbE may represent a potential alternative therapy for menopause-related obesity.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Sao Paulo, Dept Fisiol, Disciplina Fisiol Nutr, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Biol, Setor Morfofisiol & Patol, Diadema, BrazilUniv Fed Sao Paulo, Dept Fisiol, Disciplina Fisiol Nutr, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Biol, Setor Morfofisiol & Patol, Diadema, BrazilCNPq: 453924/2014-0FAPESP: 2012/03172-4FAPESP: 2014/18435-6Web of Scienc

Beneficial effects of Ginkgo biloba extract on insulin signaling cascade, dyslipidemia, and body adiposity of diet-induced obese rats

Ginkgo biloba extract (GbE) has been indicated as an efficient medicine for the treatment of diabetes mellitus type 2. It remains unclear if its effects are due to an improvement of the insulin signaling cascade, especially in obese subjects. The aim of the present study was to evaluate the effect of GbE on insulin tolerance, food intake, body adiposity, lipid profile, fasting insulin, and muscle levels of insulin receptor substrate 1 (IRS-1), protein tyrosine phosphatase 1B (PTP-1B), and protein kinase B (Akt), as well as Akt phosphorylation, in diet-induced obese rats. Rats were fed with a high-fat diet (HFD) or a normal fat diet (NFD) for 8 weeks. After that, the HFD group was divided into two groups: rats gavaged with a saline vehicle (HFD+V), and rats gavaged with 500 mg/kg of GbE diluted in the saline vehicle (HFD+Gb). NFD rats were gavaged with the saline vehicle only. At the end of the treatment, the rats were anesthetized, insulin was injected into the portal vein, and after 90s, the gastrocnemius muscle was removed. The quantification of IRS-1, Akt, and Akt phosphorylation was performed using Western blotting. Serum levels of fasting insulin and glucose, triacylglycerols and total cholesterol, and LDL and HDL fractions were measured. An insulin tolerance test was also performed. Ingestion of a hyperlipidic diet promoted loss of insulin sensitivity and also resulted in a significant increase in body adiposity, plasma triacylglycerol, and glucose levels. In addition, GbE treatment significantly reduced food intake and body adiposity while it protected against hyperglycemia and dyslipidemia in diet-induced obesity rats. It also enhanced insulin sensitivity in comparison to HFD+V rats, while it restored insulin-induced Akt phosphorylation, increased IRS-1, and reduced PTP-1B levels in gastrocnemius muscle. The present findings suggest that G. biloba might be efficient in preventing and treating obesity-induced insulin signaling impairment.Universidade Federal de São Paulo (UNIFESP) Departamento de Ciências BiológicasUniversidade Federal de São Paulo (UNIFESP) Departamento de Fisiologia Disciplina de Fisiologia da NutriçãoUniversidade Federal de São Paulo (UNIFESP) Departamento de BiociênciasUniversidade Federal de Alagoas Faculdade de NutriçãoUniversidade Federal do Rio de Janeiro Curso de NutriçãoUNIFESP, Depto. de Ciências BiológicasUNIFESP, Depto. de Fisiologia Disciplina de Fisiologia da NutriçãoUNIFESP, Depto. de BiociênciasSciEL

Efeito do extrato padronizado de ginkgo biloba sobre a sinalização serotoninérgica hipotalâmica de ratas ovariectomizadas

Post-menopausal women commonly present obesity, metabolic disorders and psychiatric disturbances, which lead to a loss of life quality. Although hormone replacement therapy (HRT) ameliorates some of these symptoms, there is a higher risk for developing cardiovascular diseases and breast cancer. Thus, finding alternative therapies with minimal side effects for management of menopause-related alterations is highly desirable. We have demonstrated that Ginkgo biloba extract (GbE) reduced visceral adiposity, softened the inflammatory status in retroperitoneal adipose tissue and improved peripheral insulin sensitivity in diet-induced obese rats. The present research aimed to study, in ovariectomized rats, whether a prolonged therapy with GbE ameliorates obesity and behavioral alterations associated to ovarian hormones absence, emphasizing hypothalamic serotonin activity. 2-mo-old rats were underwent to ovariectomy (OVX) or false-ovariectomy (Sham). After surgery, body weight and food intake were measured weekly. At 4-mo-old, the rats were divided into 4 groups: Sham, Sham+GbE, OVX and OVX+GbE. The phytotherapy therapy was carried out for 14 days. The Sham+ GbE and OVX+GbE group received a daily dose of GbE (500mg/kg) diluted in 0.9% saline (vehicle) while the Sham and OVX rats received only the vehicle. During the phytotherapy treatment, body weight and food intake were measured daily. The rats were submitted to the Elevated Plus Maze and Forced Swim Tests to evaluate anxiety and depressive-like behaviors. A subset of animals received both an intracerebroventricular injection (i.c.v., lateral ventricle) of vehicle or 300g serotonin and food intake was measured 12 hours and 24 hours after each injection. In another subset of rats, a guide cannula was steriotaxically implanted in the ventromedial hypothalamus, whereby a microdialysis probe was introduced and extracellular levels of 5-HT was measured by HPLC with electrochemical detection. We evaluated the protein expression of hypothalamic serotonergic receptors 5-HT1A, 5-HT1B and 5-HT2C, the serotonin transporter (5-HTT) and the anorectic mediator POMC. Additionally, we assessed: body fat, carcass protein content, amount of liver lipids, lipid profile, alanine and aspartate aminotransferase activity (ALT/AST), serum fasting glucose, insulin, leptin, adiponectin and tumor necrosis factor-α (TNF-α) at the end of treatment. A model of Multiple Linear Regression was applied to explain anxiety and depressive-like behaviors adopting body composition measurements and serum parameters as independent variables.The OVX group showed such anxious and depressive behaviors, and it does not respond to the anorectic action of serotonin. Moreover, ovariectomy provided an excessive body mass and visceral adiposity, hyperleptinemia and dyslipidemia, characterized by an increase in total cholesterol and LDL-cholesterol. During the phytotherapy therapy, GbE promoted hypophagic effect in the OVX+GbE group, reduced symptoms of anxiety and depression and restore the effectiveness of serotonin anorectic response. On the medial hypothalamus, GbE increased extracellular serotonin levels in the OVX+GbE group. Among the metabolic effects, GbE decreased the visceral fat, increased protein carcass content, stimulated adiponectin levels, improved lipid profile and decreased the amount of liver lipids of OVX+GbE rats. Multiple linear regressions found that insulin was a predictor of anxiety in Sham rats, while treatment with GbE removed this relationship. In OVX rats, HOMA- presented an anxiolytic effect. Lower body fat and higher HDL-cholesterol levels were considered predictors for anxiolytic behavior of OVX+GbE rats. Regarding depressive-like behaviors, visceral adiposity was pointed as the most determining factor, but this relationship was not observed in the OVX+GbE rats. The phytotherapy treatment for 14 days reduced either anxious and depressed symptoms, provided a healthier body composition, improved lipid profile, enhanced extracellular levels of serotonin in the medial hypothalamus and restored the anorectic response to serotonin. Taking together all these benefic effects, it is possible that GbE might be an effective and alternative therapy for the management of menopause-related symptoms.Mulheres na pós-menopausa comumente sofrem de obesidade, distúrbios metabólicos e desordens psiquiátricas, o que acarreta em prejuízo da qualidade de vida. Embora a terapia de reposição hormonal (TRH) amenize alguns desses sintomas, há um risco maior de desenvolvimento de doenças cardiovasculares e câncer de mama. Dessa forma, encontrar terapias alternativas e com o mínimo de efeitos colaterais no manejo das alterações associadas à menopausa é de suma importância. Já demonstramos que o extrato de Ginkgo biloba (EGb) reduziu a adiposidade visceral, amenizou o estado inflamatório no tecido adiposo retroperitoneal e melhorou a sensibilidade periférica à insulina em ratos com obesidade induzida por dieta hiperlipídica. O objetivo do presente estudo foi investigar, em ratas ovariectomizadas com 120 dias de idade, se o tratamento com extrato padronizado de Ginkgo biloba atenua as alterações relacionadas à falta de hormônios ovarianos em relação ao desenvolvimento de obesidade e comportamentos de tipo depressivo e ansioso, com ênfase na atividade serotoninérgica hipotalâmica. Ratas de 2 meses de idade foram submetidas à ovariectomia (OVX) ou falsa ovariectomia (Sham). Após a cirurgia, a massa corporal e ingestão alimentar foram avaliadas semanalmente. Aos 4 meses, as ratas foram divididas em 4 grupos: Sham, Sham+GbE, OVX e OVX+GbE. O tratamento fitoterápico foi realizado durante 14 dias. As ratas Sham+GbE e OVX+GbE receberam uma dose diária de EGb (500mg/Kg) diluída em salina 0,9% (veículo) enquanto as ratas Sham e OVX receberam apenas o veículo. Durante o tratamento, a massa corporal e ingestão alimentar foram medidas diariamente. As ratas foram submetidas aos testes do Labirinto em Cruz Elevado e Nado Forçado para avaliação de comportamento do tipo ansioso e depressivo. Um subconjunto de animais recebeu ambas injeções intracerebroventriculares (i.c.v., ventrículo lateral) de veículo e/ou 300?g de serotonina e a ingestão alimentar foi mensurada 12h e 24h após cada injeção. Em outro subconjunto de ratas, uma cânula-guia foi implantada esteriotaxicamente no hipotálamo ventromedial direito, através da qual um probe de microdiálise foi introduzido e os níveis extracelulares de 5-HT foram medidos por HPLC com detecção eletroquímica. Foi avaliada a expressão protéica hipotalâmica dos receptores serotoninérgicos 5-HT1A, 5-HT1B e 5-HT2C, do transportador de serotonina (5-HTT) e do mediador anorexígeno POMC. Adicionalmente, foram avaliados: a adiposidade corporal, conteúdo de proteína da carcaça, quantidade de lipídeos hepáticos, perfil lipídico, atividade das enzimas hepáticas alanina e aspartato aminotransferase (ALT/AST), níveis séricos de glicose de jejum, insulina, leptina, adiponectina e fator de necrose tumoral-? (TNF-?) ao término do tratamento. Foi aplicado um modelo de Regressão Linear Múltipla para explicar comportamentos do tipo ansioso e depressivo adotando as medidas de composição corporal e parâmetros séricos como variáveis independentes. O grupo OVX apresentou comportamentos de tipo ansioso e depressivo, além de não responder à ação anorexígena da serotonina. Além disso, a ovariectomia proporcionou ganho excessivo de massa e adiposidade corporais, hiperleptinemia e dislipidemia, caracterizada pelo aumento do colesterol total e do LDL-colesterol. Durante o tratamento, o EGb reduziu a ingestão alimentar do grupo OVX+GbE, amenizou os sintomas de tipo ansioso e depressivo, além de restaurar a efetividade da resposta anorexígena da serotonina. No hipotálamo medial, o EGb aumentou os níveis extracelulares de serotonina nos animais ovariectomizados tratados com o EGb. Dentre os efeitos metabólicos, o EGb diminuiu a quantidade de tecido adiposo retroperitoneal, aumentou conteúdo protéico da carcaça, estimulou a produção de adiponectina, além de melhorar o perfil lipídico e diminuir a quantidade de lipídeos hepático das ratas OVX+GbE. O modelo de Regressão Linear Múltipla identificou que a insulinemia é preditor para sintomas de ansiedade nas ratas Sham, enquanto o tratamento com EGb retirou essa relação. Nas ratas OVX, o HOMA-? apresentou efeito ansiolítico. A diminuição da adiposidade corporal e aumento do HDL-colesterol foram considerados preditores importantes para o comportamento menos ansioso das ratas OVX+GbE. Em relação aos comportamentos de tipo depressivo, a adiposidade visceral foi apontada como o fator mais determinante, porém essa relação não foi observada nas ratas OVX+GbE. A terapia com EGb durante 14 dias reduziu comportamentos de tipo ansioso e depressivo, proporcionou uma composição corporal mais saudável, melhora do perfil lipídico, aumento dos níveis extracelulares de serotonina no hipotálamo medial além de restabelecer a resposta anorexígena à serotonina. Estes efeitos benéficos em conjunto subsidiam a proposição de que o EGb consiste em uma terapia alternativa e eficaz para o manejo dos sintomas relacionados à menopausa.Dados abertos - Sucupira - Teses e dissertações (2013 a 2016

Ginkgo biloba Extract Improves Insulin Signaling and Attenuates Inflammation in Retroperitoneal Adipose Tissue Depot of Obese Rats

Due to the high incidence and severity of obesity and its related disorders, it is highly desirable to develop new strategies to treat or even to prevent its development. We have previously described that Ginkgo biloba extract (GbE) improved insulin resistance and reduced body weight gain of obese rats. In the present study we aimed to evaluate the effect of GbE on both inflammatory cascade and insulin signaling in retroperitoneal fat depot of diet-induced obese rats. Rats were fed with high fat diet for 2 months and thereafter treated for 14 days with 500 mg/kg of GbE. Rats were then euthanized and samples from retroperitoneal fat depot were used for western blotting, RT-PCR, and ELISA experiments. The GbE treatment promoted a significant reduction on both food/energy intake and body weight gain in comparison to the nontreated obese rats. In addition, a significant increase of both Adipo R1 and IL-10 gene expressions and IR and Akt phosphorylation was also observed, while NF-κB p65 phosphorylation and TNF-α levels were significantly reduced. Our data suggest that GbE might have potential as a therapy to treat obesity-related metabolic diseases, with special interest to treat obese subjects resistant to adhere to a nutritional education program

Ginkgo biloba extract (GbE) attenuates obesity and anxious/depressive-like behaviours induced by ovariectomy

Abstract While several pieces of evidence link obesity and mood disorders in menopause, the mechanisms involved are not yet fully understood. We have previously demonstrated that Ginkgo biloba extract (GbE) both attenuated diet-induced obesity of male rats and restored serotonin-induced hypophagia in ovariectomized female rats. The present study aimed at exploring whether GbE treatment ameliorates ovariectomy-related obesity and anxious/depressive-like behaviours. Wistar female rats were either ovariectomized (OVX) or sham-operated (Sham). After 2 months, either 500 mg/kg of GbE or vehicle were administered daily by gavage for 14 days. Anxious/depressive-like behaviours were assessed by the Elevated Plus Maze and the Forced Swim Tests, respectively. Ovariectomy caused high visceral adiposity, hyperleptinemia, and hypercholesterolemia, and increased the anxiety index (p = 0.048 vs. Sham + GbE) while it decreased the latency to immobility (p = 0.004 vs. Sham). GbE treatment in OVX rats improved body composition, adiponectin levels and blood lipid profile. It also reduced the anxiety index (p = 0.004) and increased the latency to immobility (p = 0.003) of OVX rats. Linear regression analysis demonstrated that leptin (p = 0.047) and total cholesterol levels (p = 0.022) were associated with anxious-like behaviours while body adiposity (p = 0.00005) was strongly associated with depressive-like behaviours. The results showed that GbE therapy was effective in attenuating the deleterious effects of ovariectomy on body composition, lipid profile, and anxious/depressive-like behaviours. Further studies are warranted to better understand the therapeutic potential of GbE in menopause