leptin and epigallocatechin-gallate

The purpose of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) to assess the effect of green tea on serum leptin and ghrelin concentrations.. We searched PubMed, ISI Web of Science, Scopus, and Google scholar databases up to December 2016. The searches included RCTs conducted in human adults, and studies on the effect of green tea and green tea extract on serum leptin and ghrelin concentrations as outcome variables. Weighted mean differences (WMDs) and standard errors (SEs) of changes in serum ghrelin and leptin levels were calculated. The random effects model was used to derive the summary mean estimates with their corresponding SEs.. Eleven RCTs were eligible to be included in the systematic review and the meta-analysis. Our analysis indicated that green tea did not significantly affect leptin and ghrelin concentrations in comparison to placebo (WMD = 1.28 ng/mL, 95% confidence interval: -0.49 to 3.05; P = 0.156, and WMD = 21.49 pg/mL, 95% confidence interval: -40.86 to 83.84; P = 0.499, respectively). However, green tea was associated with an increase in leptin concentration in studies that lasted for more than 12 wk and an increase in ghrelin in women and non-Asians.. Green tea or green tea extract might not be able to change circulatory leptin and ghrelin levels, especially with short-term interventions. More RCTs with longer duration of treatment and higher doses are necessary to assess green tea's effect on fat mass and obesity hormones.

Topics: Catechin; Ghrelin; Humans; Leptin; Obesity; Plant Extracts; Randomized Controlled Trials as Topic; Sensitivity and Specificity; Tea

Obesity and osteoporosis have grave consequences for human health, quality of life, and even the efficiency of the labor force and economy. However, these pathologies share a common cell progenitor, revealing a surprising target for drug research and development. Recent findings show that high adipocyte count in bone marrow is directly related to bone loss, as fat cells replace osteoblasts (or bone-forming cells). The objective of this review is to examine the importance of adipocyte apoptosis in the treatment of obesity and/or osteoporosis, with special emphasis on natural products as promising leads for drug development. We have induced in vivo adipocyte apoptosis, using leptin, ciliary neurotrophic factor (CNTF), beta adrenergic agonists and conjugated linoleic acid (CLA) in rodents. The results of leptin treatments on rats are suppressed food intake, reduced body weight, reduced body fat, adipocyte apoptosis, and elevated energy expenditure. Further, leptin treatment of leptin-deficient (ob/ob) mice increases endosteal bone formation and bone mineral density. Adipocyte apoptosis has also been induced in vitro using tumor necrosis factor-alpha (TNF-alpha), (-)-epigallocatechin gallate (EGCG) from Camellia sinensis and ajoene, from Allium sativum. Natural products have potential for inducing apoptosis of adipose tissue, inhibiting bone marrow adipogenesis and increasing the expression of osteogenic factors in bone, thereby yielding effective treatments for obesity and osteoporosis.

Topics: Adipocytes; Adrenergic beta-Agonists; Animals; Anti-Obesity Agents; Apoptosis; Bone Marrow; Catechin; Cell Differentiation; Ciliary Neurotrophic Factor; Disulfides; Flavonoids; Humans; Leptin; Linoleic Acid; Mesenchymal Stem Cells; Obesity; Osteoporosis; Plant Extracts; Sulfoxides; Tumor Necrosis Factor-alpha

Obesity is one of major risk factors increasing chronic diseases including type II diabetes, cardiovascular diseases, and hypertension. The effects of epigallocatechin gallate (EGCG), the major active compound in green tea, on reduced obesity and improved metabolic profiles are still controversial. Furthermore, the effects of EGCG on human adipocyte lipolysis and browning of white adipocytes have not been elucidated. This study aimed to investigate the effects of EGCG on obesity, lipolysis, and browning of human white adipocytes. The results showed that, when compared to the baseline values, EGCG significantly decreased fasting plasma triglyceride levels (

Topics: Adipocytes, Brown; Adipocytes, White; Adiponectin; Adult; Blood Glucose; Blood Pressure; Catechin; Humans; Kidney; Kisspeptins; Leptin; Lipolysis; Liver; Middle Aged; Obesity; RNA, Messenger; Triglycerides; Uncoupling Protein 1

Topics: Adiponectin; Adiposity; Appetite; Blood Glucose; Body Mass Index; Brazil; Catechin; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Female; Gastric Emptying; Humans; Hunger; Insulin; Leptin; Satiation; Young Adult

Green tea extract (GTE) may be involved in a favourable post-prandial response to high-carbohydrate meals. The catechol-O-methyltransferase (COMT) genotype may modify these effects. We examined the acute effects of GTE supplementation on the post-prandial response to a high-carbohydrate meal by assessing appetite-associated hormones and glucose homeostasis marker concentrations in women who consumed 843 mg of (-)-epigallocatechin-3-gallate (EGCG) or placebo capsules for 11-12 months.. Sixty Caucasian post-menopausal women (body mass index ≥ 25.0 kg m. Plasma leptin, ghrelin and adiponectin did not differ between GTE and placebo at any time point; COMT genotype did not modify these results. Participants randomised to GTE with the high-activity form of COMT (GTE-high COMT) had higher insulin concentrations at time 0, 0.5 and 1.0 h post-meal compared to all COMT groups randomised to placebo. Insulin remained higher in the GTE-high COMT group at 1.5, 2.0 and 2.5 h compared to Placebo-low COMT (P < 0.02). GTE-high COMT had higher insulin concentrations at times 0, 0.5, 1.0, 1.5 and 2.0 h compared to the GTE-low COMT (P ≤ 0.04). Area under the curve measurements of satiety did not differ between GTE and placebo.. GTE supplementation and COMT genotype did not alter acute post-prandial responses of leptin, ghrelin, adiponectin or satiety, although it may be involved in post-meal insulinaemic response of overweight and obese post-menopausal women.

Topics: Adiponectin; Aged; Antioxidants; Body Mass Index; Catechin; Catechol O-Methyltransferase; Dietary Supplements; Double-Blind Method; Female; Genotype; Ghrelin; Humans; Insulin; Leptin; Middle Aged; Obesity; Overweight; Plant Extracts; Postmenopause; Postprandial Period; Surveys and Questionnaires; Tea

Green tea consumption has been associated with favorable changes in body weight and obesity-related hormones, although it is not known whether these changes result from green tea polyphenols or caffeine.. We examined the impact of decaffeinated green tea extract (GTE) containing 843 mg of (-)-epigallocatechin-3-gallate on anthropometric variables, obesity-associated hormones, and glucose homeostasis.. The Minnesota Green Tea Trial was a 12-mo randomized, double-blind, placebo-controlled clinical trial of 937 healthy postmenopausal women assigned to either decaffeinated GTE (1315 mg total catechins/d) or a placebo, stratified by catechol-O-methyltransferase (COMT) genotype. This study was conducted in a subset of 237 overweight and obese participants [body mass index (BMI) ≥25 kg/m(2)].. No changes in energy intake, body weight, BMI, or waist circumference (WC) were observed over 12 mo in women taking GTE (n = 117) or placebo (n = 120). No differences were seen in circulating leptin, ghrelin, adiponectin, or glucose concentrations at month 12. Participants randomly assigned to GTE with baseline insulin ≥10 μIU/mL (n = 23) had a decrease in fasting serum insulin from baseline to month 12 (-1.43 ± 0.59 μIU/mL), whereas those randomly assigned to placebo with baseline insulin ≥10 μIU/mL (n = 19) had an increase in insulin over 12 mo (0.55 ± 0.64 μIU/mL, P < 0.01). Participants with the homozygous high-activity (G/G) form of COMT had significantly lower adiponectin (5.97 ± 0.50 compared with 7.58 ± 0.53 μg/mL, P = 0.03) and greater insulin concentrations (7.63 ± 0.53 compared with 6.18 ± 0.36 μIU/mL, P = 0.02) at month 12 compared with those with the low-activity (A/A) genotype, regardless of treatment group.. Decaffeinated GTE was not associated with reductions in body weight, BMI, or WC and did not alter energy intake or mean hormone concentrations in healthy postmenopausal women over 12 mo. GTE decreased fasting insulin concentrations in those with elevated baseline fasting concentrations. The high-activity form of the COMT enzyme may be associated with elevations in insulin and a reduction in adiponectin concentrations over time. This trial was registered at http://www.clinicaltrials.gov as NCT00917735.

Topics: Adiponectin; Administration, Oral; Aged; Blood Glucose; Body Mass Index; Body Weight; Caffeine; Catechin; Catechol O-Methyltransferase; Double-Blind Method; Energy Intake; Fasting; Female; Genotype; Ghrelin; Humans; Insulin; Leptin; Middle Aged; Motor Activity; Nutrition Assessment; Obesity; Overweight; Plant Extracts; Polyphenols; Postmenopause; Tea; Waist Circumference

Green tea (epigallocatechin gallate + caffeine) and protein each were shown to improve body weight maintenance after weight loss.. We investigated the effect of a green tea-caffeine mixture added to a high-protein (HP) diet on weight maintenance (WM) after body weight loss in moderately obese subjects.. A randomized, placebo-controlled, double-blind parallel trial was conducted in 80 overweight and moderately obese subjects [age (mean +/- SD): 44 +/- 2 y; body mass index (BMI; in kg/m(2)): 29.6 +/- 2.0] matched for sex, age, BMI, height, body mass, and with a habitually low caffeine intake. A very-low-energy diet intervention during 4 wk was followed by 3 mo of WM; during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine/d) or placebo, both in addition to an adequate protein (AP) diet (50-60 g protein/d) or an HP diet (100-120 g protein/d).. Subjects lost 7.0 +/- 1.6 kg, or 8.2 +/- 2.0%, body weight (P < 0.001). During the WM phase, WM, resting energy expenditure, and fat-free mass (FFM) increased relatively in both the HP groups and in the AP + green tea-caffeine mixture group (P < 0.05), whereas respiratory quotient and body fat mass decreased, all compared with the AP + placebo group. Satiety increased only in both HP groups (P < 0.05). The green tea-caffeine mixture was only effective with the AP diet.. The green tea-caffeine mixture, as well as the HP diet, improved WM independently through thermogenesis, fat oxidation, sparing FFM, and, for the HP diet, satiety; a possible synergistic effect failed to appear.

Topics: Adolescent; Adult; Appetite; Blood Glucose; Body Composition; Body Weight; Caffeine; Catechin; Dietary Proteins; Fatty Acids, Nonesterified; Female; Glycerol; Humans; Insulin; Leptin; Male; Middle Aged; Tea; Thermogenesis; Triglycerides; Weight Loss; Young Adult

Leptin is a nutritional cytokine, and it is closely related to the progression of cancer. However, the detailed effect of leptin in lung cancer remains poorly known. We found leptin-induced A549 cell proliferation, migration, and invasion, which was reversed by epigallocatechin gallate (EGCG) from green tea. Currently, we found that leptin-triggered M2 polarization of tumor-associated macrophages was inhibited by EGCG. Then, to investigate the underlying mechanism effect of leptin on A549 cells was studied. Aberrant activities of STAT1 are implicated in cancer development. Based on the cancer genome atlas data, STAT1 acted as an oncogene in lung cancer and EGCG greatly reduced STAT1 expression in A549 cells. Ferroptosis is an iron-dependent nonapoptotic cell death. STAT1 served as a transcriptional activator for SLC7A11. EGCG restrained lung cancer cell growth induced by leptin via targeting STAT1-SLC7A11 mediated ferroptosis. A high-fat diet (HFD) feeding condition was combined with a multi-dose urethane-induced lung tumorigenesis model using C57BL/6J mice. Obesity was induced with a 60 kcal% HFD feeding. Serum leptin levels increased in urethane-administered and HFD-fed mice. Compared to the control diet-fed mice, the HFD-fed mice exhibited increased lung tumor burden and typical pro-tumorigenic STAT1 activation in lung tissues after urethane administration. In addition, HFD alters the gut microbiome by decreasing the abundance of Clostridia and by increasing the abundance of Deltaproteobacteria and Epsilonproteobacteria while EGCG exhibited a reversed effect. These findings suggested that leptin promoted the development of lung tumorigenesis in vitro and in vivo via mediating activation of the STAT-SLC7A11 pathway and gut microbiota.

Topics: Animals; Carcinogenesis; Diet, High-Fat; Gastrointestinal Microbiome; Leptin; Lung; Lung Neoplasms; Mice; Mice, Inbred C57BL; Obesity; Urethane

Topics: Apoptosis; Catechin; Dopaminergic Neurons; Humans; Leptin; Liposomes; Parkinson Disease; Phosphatidic Acids; Resveratrol

Obese subjects have an increased risk of developing triple-negative breast cancer (TNBC), in part associated with the chronic low-grade inflammation state. On the other hand, epidemiological data indicates that increased consumption of polyphenol-rich fruits and vegetables plays a key role in reducing incidence of some cancer types. Here, we tested whether green tea-derived epigallocatechin-3-gallate (EGCG) could alter adipose-derived mesenchymal stem cell differentiation into adipocytes, and how this impacts the secretome profile and paracrine regulation of the TNBC invasive phenotype. Here, cell differentiation was performed and conditioned media (CM) from preadipocytes and mature adipocytes harvested. Human TNBC-derived MDA-MB-231 real-time cell migration was performed using the exCELLigence system. Differential gene arrays and RT-qPCR were used to assess gene expression levels. Western blotting was used to assess protein expression and phosphorylation status levels. In vitro vasculogenic mimicry (VM) was assessed with Matrigel. EGCG was found to inhibit the induction of key adipogenic biomarkers, including lipoprotein lipase, adiponectin, leptin, fatty acid synthase, and fatty acid binding protein 4. Increased TNBC-derived MDA-MB-231 cell chemotaxis and vasculogenic mimicry were observed in response to mature adipocytes secretome, and this was correlated with increased STAT3 phosphorylation status. This invasive phenotype was prevented by EGCG, the JAK/STAT inhibitors Tofacitinib and AG490, as well as upon STAT3 gene silencing. In conclusion, dietary catechin-mediated interventions could, in part through the inhibition of adipogenesis and modulation of adipocytes secretome profile, prevent the onset of an obesogenic environment that favors TNBC development.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adiponectin; Animals; Catechin; Cell Differentiation; Cell Line, Tumor; Cell Movement; Cell Proliferation; Culture Media, Conditioned; Female; Humans; Leptin; Mesenchymal Stem Cells; Mice; Paracrine Communication; STAT3 Transcription Factor; Tea; Triple Negative Breast Neoplasms

Leptin contributes to the pathogenesis of vascular repair and cardiovascular events. This study evaluated the molecular mechanism of EGCG in balloon injury-induced leptin expression. According to immunohistochemical and confocal analyses, leptin expression was increased and the aortic lumen exhibited narrowing after balloon injury. EGCG treatment attenuated leptin expression and diminished neointimal formation. The in vitro study showed that angiotensin II (Ang II) induced the migration and proliferation of cultured vascular smooth muscle cells (VSMCs), whereas treatment with EGCG, leptin siRNA, and c-Jun siRNA inhibited the migration and proliferation of VSMCs significantly. The EMSA shows that balloon injury increased AP-1-binding activity, and EGCG and c-Jun siRNA inhibited the AP-1-binding activity. Western blot and real-time RT-PCR analyses revealed similar results in intimal tissue samples. In summary, balloon injury induces leptin expression in the carotid artery of rats, and EGCG inhibits leptin expression through the JNK/AP-1 pathway and also attenuates neointimal formation.

Topics: Angioplasty, Balloon; Angiotensin II; Animals; Aorta, Thoracic; Carotid Arteries; Carotid Artery Injuries; Catechin; Cell Movement; Cells, Cultured; Leptin; Male; Muscle, Smooth, Vascular; Neointima; Rats; Rats, Wistar; RNA, Small Interfering

Obesity and diabetes mellitus are risk factors for colon cancer. The activation of the insulin-like growth factor (IGF)/IGF-IR axis plays a critical role in this carcinogenesis. (-)-Epigallocatechin gallate (EGCG), the major constituent of green tea, seems to have both antiobesity and antidiabetic effects. This study examined the effects of EGCG on the development of azoxymethane-induced colonic premalignant lesions in C57BL/KsJ-db/db (db/db) mice, which are obese and develop diabetes mellitus. Male db/db mice were given four weekly s.c. injections of azoxymethane (15 mg/kg body weight) and then they received drinking water containing 0.01% or 0.1% EGCG for 7 weeks. At sacrifice, drinking water with EGCG caused a significant decrease in the number of total aberrant crypt foci, large aberrant crypt foci, and beta-catenin accumulated crypts in these mice, all of which are premalignant lesions of the colon. The colonic mucosa of db/db mice expressed high levels of the IGF-IR, phosphorylated form of IGF-IR (p-IGF-IR), p-GSK-3beta, beta-catenin, cyclooxygenase-2, and cyclin D1 proteins, and EGCG in drinking water caused a marked decrease in the expression of these proteins. Treating these mice with EGCG also caused an increase in the serum level of IGFBP-3 while conversely decreasing the serum levels of IGF-I, insulin, triglyceride, cholesterol, and leptin. EGCG overcomes the activation of the IGF/IGF-IR axis, thereby inhibiting the development of colonic premalignant lesions in an obesity-related colon cancer model, which was also associated with hyperlipidemia, hyperinsulinemia, and hyperleptinemia. EGCG may be, therefore, useful in the chemoprevention or treatment of obesity-related colorectal cancer.

Topics: Animals; Anticarcinogenic Agents; Azoxymethane; Carcinoma; Catechin; Cholesterol; Colonic Neoplasms; Diabetes Mellitus, Experimental; Drug Evaluation, Preclinical; Insulin; Intestinal Mucosa; Leptin; Male; Mice; Mice, Inbred C57BL; Precancerous Conditions; Receptor, IGF Type 1; Triglycerides

To examine the antiobesity effect of epigallocatechin gallate (EGCG), a green tea bioactive polyphenol in a mouse model of diet-induced obesity.. Obesity was induced in male New Zealand black mice by feeding of a high-fat diet. EGCG purified from green tea (TEAVIGO) was supplemented in the diet (0.5 and 1%). Body composition (quantitative magnetic resonance), food intake, and food digestibility were recorded over a 4-week period. Animals were killed and mRNA levels of uncoupling proteins (UCP1-3), leptin, malic enzyme (ME), stearoyl-CoA desaturase-1 (SCD1), glucokinase (GK), and pyruvate kinase (PK) were analysed in different tissues. Also investigated were acute effects of orally administered EGCG (500 mg/kg) on body temperature, activity (transponders), and energy expenditure (indirect calorimetry).. Dietary supplementation of EGCG resulted in a dose-dependent attenuation of body fat accumulation. Food intake was not affected but faeces energy content was slightly increased by EGCG, indicating a reduced food digestibility and thus reduced long-term energy absorption. Leptin and SCD1 gene expression in white fat was reduced but SCD1 and UCP1 expression in brown fat was not changed. In liver, gene expression of SCD1, ME, and GK was reduced and that of UCP2 increased. Acute oral administration of EGCG over 3 days had no effect on body temperature, activity, and energy expenditure, whereas respiratory quotient during night (activity phase) was decreased, supportive of a decreased lipogenesis and increased fat oxidation.. Dietary EGCG attenuated diet-induced body fat accretion in mice. EGCG apparently promoted fat oxidation, but its fat-reducing effect could be entirely explained by its effect in reducing diet digestibility.

Topics: Animals; Antioxidants; Body Composition; Body Temperature; Calorimetry, Indirect; Carrier Proteins; Catechin; Dietary Supplements; Eating; Glucokinase; Intestinal Absorption; Ion Channels; Leptin; Lipid Metabolism; Malate Dehydrogenase; Male; Membrane Proteins; Membrane Transport Proteins; Mice; Mice, Inbred NZB; Mitochondrial Proteins; Obesity; Oxidation-Reduction; Pyruvate Kinase; Stearoyl-CoA Desaturase; Tissue Distribution; Uncoupling Protein 1; Uncoupling Protein 2; Uncoupling Protein 3

Green tea polyphenols, especially the catechin, (-)-epigallocatechin gallate (EGCG), have been proposed as a cancer chemopreventative based on a variety of laboratory studies. For clear assessment of the possible physiological effects of green tea consumption, we injected pure green tea catechins ip into rats and studied their acute effects on endocrine systems. We found that EGCG, but not related catechins, significantly reduced food intake; body weight; blood levels of testosterone, estradiol, leptin, insulin, insulin-like growth factor I, LH, glucose, cholesterol, and triglyceride; as well as growth of the prostate, uterus, and ovary. Similar effects were observed in lean and obese male Zucker rats, suggesting that the effect of EGCG was independent of an intact leptin receptor. EGCG may interact specifically with a component of a leptin-independent appetite control pathway. Endocrine changes induced by parenteral administration of EGCG may relate to the observed growth inhibition and regression of human prostate and breast tumors in athymic mice treated with EGCG as well as play a role in the mechanism by which EGCG inhibits cancer initiation and promotion in various animal models of cancer.

Topics: Animals; Blood Cell Count; Blood Chemical Analysis; Body Weight; Catechin; Eating; Endocrine Glands; Female; Genitalia; Gonadal Steroid Hormones; Growth Hormone; Insulin; Insulin-Like Growth Factor I; Leptin; Luteinizing Hormone; Male; Organ Size; Rats; Rats, Sprague-Dawley; Rats, Zucker; Tea; Testosterone