Modulation of hypothalamic AMPK and hypothalamic neuropeptides in the control of eating behavior: A systematic review.

Eating behavior is regulated by central and peripheral signals, which interact to modulate the response to nutrient intake. Central control is mediated by the hypothalamus through neuropeptides that activate the orexigenic and anorexigenic pathways. Energy homeostasis depends on the efficiency of these regulatory mechanisms. This neuroendocrine regulation of hunger and appetite can be modulated by nutritional sensors such as adenosine monophosphate-activated protein kinase (AMPK). Thus, this systematic review discusses the literature on correlations between AMPK and hypothalamic neuropeptides regarding control of eating behavior. Lilacs, PubMed/Medline, ScienceDirect, and Web of Science were searched for articles published from 2009 to 2021 containing combinations of the following descriptors: "eating behavior," "hypothalamus," "neuropeptide," and "AMPK." Of the 1330 articles found initially, 27 were selected after application of the inclusion and exclusion criteria. Of the selected articles, 15 reported decreased AMPK activity, due to interventions using angiotensin II infusion, fructose, glucose, cholecystokinin, leptin, or lipopolysaccharide (LPS) injection; dietary control through a low-protein diet or a high-fat diet (60 % fat); induction of hyperthyroidism; or injection of AMPK inhibitors. Seven studies showed a decrease in neuropeptide Y (NPY) through CV4 AICAR administration; fructose, glucose, leptin, or angiotensin II injections; or infusion of LPS from Escherichia coli and liver kinase B1 (LKB1) overexpression. Eleven studies reported a decrease in food consumption due to a decrease in AMPK activity and/or hypothalamic neuropeptides such as NPY. The results indicate that there is a relationship between AMPK and the control of eating behavior: a decrease in AMPK activity due to a dietary or non-dietary stimulus is associated with a consequent decrease in food intake. Furthermore, AMPK activity can be modulated by glucose, thyroid hormones, estradiol, leptin, and ghrelin.

Potential therapeutic effects of green tea on obese lipid profile - a systematic review.

Background: Green tea, obtained from the plant Camellis sinensis, is one of the oldest drinks in the world and contains numerous bioactive compounds. Studies have demonstrated the efficacy of green tea in preventing obesity and cardiovascular diseases that may be related to the reduction of lipid levels. Aim: This study aimed to evidence, through a systematic review, the therapeutic potential of green tea on the lipid profile in preclinical studies in obese animals and clinical studies in obese individuals. Methods: This systematic review follows the recommendations of the preferred report items for systematic reviews and meta-analyses. The electronic databases, PubMed (Medline), Science Direct, Scopus, and Web of Science were consulted. Articles from January 2009 to December 2019 were selected. Results: This search resulted in twenty-nine articles were included cirtically reviewed. In experimental studies, green tea administration has been shown to reduce total cholesterol, triglycerides and low-density lipoprotein cholesterol in animals exposed to obesity-inducing diet. In humans' studies green tea was not shown to be effective for obese lipid control. Because supplementation with green tea extract reduced total cholesterol, triglycerides, low-density lipoprotein for three months at a specific dose. Conclusion: Therefore, green tea appears to act as a protective agent for dyslipidemia in obesity-induced animals. In human studies, green tea has not been shown to be effective in controlling obese lipids.

Perinatal and post-weaning exposure to an obesogenic diet promotes greater expression of nuclear factor-κB and tumor necrosis factor-α in white adipose tissue and hypothalamus of adult rats.

Aim: To analyze the effects of exposure to a high-fat diet during the perinatal period and after weaning on white adipose tissue accumulation and gene expression of TNF- α and NF- κB.Method: Wistar female rats were fed with high-fat (H) or control (C) diet during pregnancy and lactation. The offspring were allocated into four groups: Control Control (CC), offspring of mothers GC, fed a control diet after weaning; Control High-fat (CH), offspring of mothers GC, fed a hight-fat diet after weaning; High-fat Control (HC), offspring of mothers GH, fed with control diet after weaning; and High-fat High-fat (HH), offspring of mothers GH, fed a H diet after weaning.Results: HH and HC groups showed increased body weight compared to CC group and increases in caloric intake, larger amount of white adipose tissue and adipocyte size compared to CC and CH groups. The HH and CH groups showed higher NF-kB expression in white adipose tissue compared to the CC and HC groups, and the HH group also showed higher TNF- α expression. In the hypothalamus, the HH and HC groups exhibited higher TNF- α expression compared to the CC and CH groups.Conclusion: Perinatal and post-weaning exposure to the high-fat diet increases the amount of white adipose tissue, adipocyte size, and expression of the inflammatory genes TNF-α and NF-kB.

Reduction of relative handgrip strength and cardiometabolic risk in individuals with HIV/AIDS.

INTRODUCTION: Low handgrip strength (HS) is associated with cardiometabolic alterations that have affected people with HIV/AIDS. METHODS: This was a cross-sectional study performed in adults receiving antiretroviral treatment. HS was evaluated using a dynamometer and divided by body weight to obtain the relative strength. The association between relative HS and overweight, increased waist circumference (WC), high body fat percentage, glycemia, and lipid ratios were assessed using logistic regression. RESULTS: Low relative HS was identified in 35% of participants and associated with increased WC (odds ratio = 9.7; 95% confidence interval = 2.8-33.0). CONCLUSIONS: The prevalence of low HS was high and associated with increased WC.

Reduction of relative handgrip strength and cardiometabolic risk in individuals with HIV/AIDS

Abstract INTRODUCTION: Low handgrip strength (HS) is associated with cardiometabolic alterations that have affected people with HIV/AIDS. METHODS: This was a cross-sectional study performed in adults receiving antiretroviral treatment. HS was evaluated using a dynamometer and divided by body weight to obtain the relative strength. The association between relative HS and overweight, increased waist circumference (WC), high body fat percentage, glycemia, and lipid ratios were assessed using logistic regression. RESULTS: Low relative HS was identified in 35% of participants and associated with increased WC (odds ratio = 9.7; 95% confidence interval = 2.8-33.0). CONCLUSIONS: The prevalence of low HS was high and associated with increased WC.

Factors associated with sarcopenia in institutionalized elderly.

INTRODUCTION: The sarcopenia is a negative aspect for the health of the elderly, increased the risk for disease and mortality. Additionally can contributes greatly to functional reducing capacity and quality of life. OBJECTIVE: To identify the prevalence and factors associated with sarcopenia in institutionalized elderly. METHODS: This is a cross-sectional study, conducted with 216 elderly people, aged ≥ 60 years, of both sexes, residents in long-term care facilities in Salvador-Bahia, Brazil. To identify sarcopenia was used the skeletal muscle Index. Covariates were considered: gender, age, time of institutionalization, type of institution, body mass index and functional capacity. The Association between sarcopenia and covariates was evaluated using the Poisson regression model with robust variance. RESULTS: The prevalence of sarcopenia in the elderly was 72.2% and this condition was associated with male sex (PR = 1,33; CI 95% = 1,081,65), thinness (PR = 1,29; CI 95% = 1,16-1,43) and obesity (PR = 0,37; CI 95% = 0,23-0,61). CONCLUSION: The prevalence of sarcopenia was high among the elderly living in long-term institutions, especially among men. Elderly with thinness showed greater impairment of muscle reserves, while the state of obesity was protective.

A perinatal palatable high-fat diet increases food intake and promotes hypercholesterolemia in adult rats.

The main goal of the present study was to evaluate the long-term effects of a perinatal palatable high-fat diet on the food intake and cholesterol profile of adult rats. Male Wistar rats (aged 22 days) were divided into two groups according to their mother's diet during gestation and lactation (C (p), n = 10; pups from control mothers; and HL(p) n = 10; pups from mothers fed a palatable high-fat diet). At the 76th day, pups were housed individually for 14 days, and daily food consumption was determined during a period of 6 days. Blood from 100-day-old rats was sampled by cardiac puncture. Fasting (12 h) serum glucose, total cholesterol, LDL-C, HDL-C, triglycerides (TG), and VLDL-C levels were determined. The measurement of food intake was higher in the animals submitted to a hyperlipidic diet during the perinatal period. Serum total cholesterol, LDL-C, HDL-C, TG, VLDL-C and glycemia were increased in the HL(p) group compared to the control group. Our findings show that an early life environment with a high-fat diet can contribute to metabolic disease in later life.

Methods of predicting visceral fat in Brazilian adults and older adults: a comparison between anthropometry and computerized tomography

Visceral adipose tissue (VAT) is linked with the metabolic consequences of obesity, being necessary the use alternative methods of predicting this type of fat, like anthropometry. The objective of this study was assess the performance of anthropometry in predicting visceral fat measured with computerized tomography in adults and older adults. Study transversal with 197 individuals underwent computerized tomography (CT) and anthropometry. The variables analized were: visceral adipose tissue area by CT, Sagittal Abdominal Diameter (SAD), Waist Circumference (WC) and Waist-Hip Ratio (WHR). A descriptive analysis, Pearson correlation and ROC curve were carried out. We observed Correlations higher than 0.7 (p=0.000) between the SAD, WC and the VAT area were found in adult men and older men and in adult women. WHR displayed the least correlations. The most sensitive and specific SAD cut-off points were equal for all the men (Adults: 20.2 cm /Older adults: 20.2 cm) but different for the women (Adults: 21.0 cm; sens.: 83.3; spec.: 79.1 /Older adults: 19.9 cm; sens.: 81.0; spec.:79.3). The WC cut-off points that identified a VAT area =130cm² were 90.2 cm and 92.2 cm for men (adult men - sens.: 86.7; spec.: 86.1 - and older men- sens.: 79.3; spec.: 77.8 -respectively), while for women the recorded values were 92.3 cm (adult women- sens.: 83.3; spec: 81.4) and 88.2 cm (older women - sens.:76.2; spec.: 69.0).This study showed that WC and SAD achieved the best performance in the identification of visceral fat considered at risk for the development of cardiometabolic diseases in adults and older adults.

Tejido adiposo visceral (TAV) está vinculado con las consecuencias metabólicas de la obesidad, siendo necesario el uso de métodos alternativos de predicción de este tipo de grasa, como la antropometría. El objetivo de este estudio fue evaluar el desempeño de la antropometría en la predicción de la grasa visceral medido con tomografía computarizada en adultos y adultos mayores. Estudio transversal con 197 individuos sometidos a tomografía computarizada y la antropometría. Las variables fueron: área de TAV, diámetro abdominal sagital (DAS), circunferencia de cintura (CC) y el índice cintura-cadera (RCC). Análisis descriptivo, de correlación de Pearson y la Curva ROC se llevaron a cabo. Hemos observado correlaciones superiores a 0,7 (p=0,000) entre el DAS, CC y TAV en los hombres adultos y adultos mayores y en mujeres adultas. RCC muestren la mínima correlación. Los puntos de corte de DAS más sensible y específico son iguales para los hombres (adultos y adultos mayores: 20,2cm), pero diferente para las mujeres (Adultos: 21,0cm - sens.:83.3; espec.:79.1 /adultos mayores: 19,9cm - sens.: 81.0; espec.: 79.3). El CC de los puntos de corte fueron de 90,2cm y 92,2cm para los hombres (Hombres adultos- sens.: 86.7; espec.: 86.1- y los hombres mayores - sens.: 79.3; espec.: 77.8, respectivamente), mientras que para las mujeres los valores registrados fueron de 92.3cm (mujeres adultas- sens.: 83.3; espec.:81.4) y 88.2cm (mujeres mayores- sens.: 76.2; espec.:69.0). Este estudio mostró que la CC y el DAS lograr el mejor rendimiento en la identificación de la grasa visceral considerados de riesgo para el desarrollo de enfermedades cardiometabólicas en los adultos y adultos mayores.

Efeito do tratamento com triptofano sobre parâmetros do comportamento alimentar em ratos adultos submetidos à desnutrição neonatal / Effects of tryptophan on the eating behavior of adult rats with neonatal malnutrition

OBJETIVO: Investigou-se os efeitos do tratamento com triptofano sobre o consumo alimentar em ratos adultos, submetidos ou não a desnutrição precoce. MÉTODOS: Sessenta e quatro ratos Wistar machos foram divididos em nutridos (n=32, caseína=17 por cento) e desnutridos (n=32, caseína=8 por cento), de acordo com a dieta materna empregada no período de lactação. Após o desmame, todos os ratos receberam dieta com 23 por cento de proteína. Pesos corporais foram avaliados no sétimo, vigésimo primeiro e septuagésimo dias de vida. Aos setenta dias de idade, cada grupo nutricional foi dividido em subgrupos: Nutrido-Salina (n=16) e Nutrido-Triptofano (n=16), Desnutrido-Salina (n=16) e Desnutrido-Triptofano (n=16). Os grupos receberam diariamente 1,0mL/100g de triptofano, na dose de 50mg/kgP ou salina (0,9 por centoNaCl), durante 14 dias. Neste período foram realizados os estudos dos parâmetros do comportamento alimentar. Posteriormente obteve-se a média do consumo alimentar relativo e a média do ganho de peso relativo. As análises estatísticas foram feitas utilizando os testes t Student e ANOVA seguido de Tukey, com p<0,05. RESULTADOS: As ninhadas de mães alimentadas com dieta hipoproteica mantiveram pesos inferiores comparados com as ninhadas nutridas (p<0,01) até os setenta dias de vida. Os ratos nutridos tratados com triptofano (M=6,88, DP=0,05) reduziram a ingestão alimentar comparados aos nutridos salina (M=7,27, DP=0,08) (p<0,01). Contudo, não houve efeito sobre o ganho de peso. Entre os desnutridos nenhuma diferença foi encontrada. CONCLUSÃO: Nesse estudo, a restrição proteica neonatal alterou a evolução ponderal em ratos. Além disso, a desnutrição precoce tornou os ratos adultos resistentes aos efeitos inibitórios do triptofano sobre a ingestão alimentar.

OBJECTIVE: This study investigated the effects of tryptophan on the eating behavior of adult rats submitted or not to early malnutrition. METHODS: Sixty-four male Wistar rats were divided into nourished (n=32, casein=17 percent) and malnourished (n=32, casein=8 percent) according to the diet given to the dam during lactation. After weaning, all rats were fed a diet with a protein content of 23 percent. The rats were weighed on day 7, day 21 and day 70 after birth. On day 70 after birth, each nutritional group was divided into 4 subgroups: nourished-saline (n=16), nourished-tryptophan (n=16), malnourished-saline (n=16) and malnourished-tryptophan (n=16). The tryptophan groups were given 1.0mL/100g of tryptophan for 14 days, at a dosage of 50mg/kgw of body weight and the saline groups were given 1.0mL/100g of 0.9 percent NaCl, also for 14 days. The eating behavior parameters were assessed during this period. The mean relative food intake and mean relative weight gain were then determined. The statistical analyses were done by the Student's t-test and ANOVA, followed by the Tukey test, with p<0.05. RESULTS: During the first 70 days of life, pups from protein-malnourished damns remained lighter than pups from well-nourished damns (p<0.01). Well-nourished rats treated with tryptophan (M=6.88, SD=0.05) ate less than those given saline (M=7.27, SD=0.08) (p<0.01) but weight was unaffected. No difference was found for the malnourished rats. CONCLUSION: In this study, neonatal protein restriction affected weight gain in rats. Furthermore, early malnutrition made adult rats resistant to the inhibitory effects of tryptophan on food intake.

Neonatal treatment with fluoxetine reduces depressive behavior induced by forced swim in adult rats

Serotonin plays a role at the pathophysiology of depression in humans and in experimental models. The present study investigated the depressive behavior and the weigh evolution in adult rats (60 days) treated from the 1st to the 21st postnatal day with fluoxetine, a selective serotonin reuptake inhibitor (10 mg/kg, sc, daily). The depressive behavior was induced by the forced swim test (FST). The animals were submitted to two sessions of FST: 1st session for 15 min and the 2nd session 24h later, for 5 min. During the 2nd session the Latency of the Attempt of Escape (LAE) and Behavioral Immobility (BI) were appraised. The Fluoxetine group when compared to the Control group, showed an increase in LAE and a decrease in BI. The neonatal administration of fluoxetine reduced the depressive behavior in adult rats, possibly by increase in the brain serotonergic activity. This alteration can be associated to process of neuroadaptation

Neonatal treatment with fluoxetine reduces depressive behavior induced by forced swim in adult rats.

Serotonin plays a role at the pathophysiology of depression in humans and in experimental models. The present study investigated the depressive behavior and the weigh evolution in adult rats (60 days) treated from the 1st to the 21st postnatal day with fluoxetine, a selective serotonin reuptake inhibitor (10 mg/kg, sc, daily). The depressive behavior was induced by the forced swim test (FST). The animals were submitted to two sessions of FST: 1st session for 15 min and the 2nd session 24h later, for 5 min. During the 2nd session the Latency of the Attempt of Escape (LAE) and Behavioral Immobility (BI) were appraised. The Fluoxetine group when compared to the Control group, showed an increase in LAE and a decrease in BI. The neonatal administration of fluoxetine reduced the depressive behavior in adult rats, possibly by increase in the brain serotonergic activity. This alteration can be associated to process of neuroadaptation.