Emerging therapeutic strategies for obesity

Hawthorn carbon dots: a novel therapeutic agent for modulating body weight and hepatic lipid profiles in high-fat diet-fed mice

Obesity, a chronic metabolic disorder characterized by excessive body weight and adipose tissue accumulation, is intricately linked to a spectrum of health complications. It is driven by a confluence of factors, including gut microbiota dysbiosis, inflammation, and oxidative stress, which are pivotal in its pathogenesis. A multifaceted therapeutic strategy that targets these interrelated pathways is essential for effective obesity management. In this context, biomass-derived carbon dots have emerged as a promising avenue due to their diverse biological activities and potential in nanomedicine. Our study presents the synthesis of multi-modal hawthorn carbon dots (HCD), employing a green hydrothermal carbonization method that diverged from traditional stir-frying techniques. This eco-friendly approach facilitates the preparation of HCD, emphasizing the role of sugar compounds as the primary carbon source in their formation. In vitro assays demonstrate that HCD possess potent anti-inflammatory and antioxidant properties, which are crucial in combating the oxidative stress and inflammation associated with obesity. We further investigate the impact of HCD intervention in a high-fat diet (HFD)-induced obesity mouse model, employing both post-modeling and simultaneous modeling administration strategies. Our findings reveal that HCD treatment significantly reduces body weight and hepatic lipid accumulation in HFD mice, concurrently enhancing glucose tolerance and alleviating insulin resistance. Moreover, antibiotic perturbation experiments, complemented by bioinformatics analysis of colon microbiota, indicate that HCD substantially modulate gut microbiota composition. This modulation is associated with the amelioration of obesity-related conditions, suggesting that HCD may exert their beneficial effects through the regulation of gut microbiota, in addition to their anti-inflammatory and antioxidant activities. These multimodal mechanisms of action position HCD as a promising candidate for the prevention and treatment of obesity, offering a novel therapeutic strategy that targets the complex interplay of factors involved in this metabolic disorder.

Mechanisms of combined deer antler polysaccharides and postbiotics supplementation for regulating obesity in mice

Objective

This study investigated the mechanisms related to lipid metabolism regulation after combined supplementation with deer antler polysaccharides and postbiotics.

Methods

Thirty-two male mice were divided into high-fat diet, HD + deer antler polysaccharides, HD + Bacillus coagulans postbiotics, and HD + deer antler polysaccharides + B. coagulans postbiotics groups. The diets contained 60% fat. After 9 weeks, the effects of deer antler polysaccharides and postbiotics on lipid metabolism were assessed through blood biochemical, histological tissue staining, and polymerase chain reaction analyses.

Results

Supplementation with deer antler polysaccharides and postbiotics significantly inhibited weight gain in obese mice, reduced serum total cholesterol, triglyceride, and low-density lipoprotein levels and markedly increased the serum high-density lipoprotein level. Additionally, hepatic lipid droplet accumulation and adipocyte hypertrophy improved. The expressions of the lipid synthesis genes, sterol regulatory element-binding protein 1 (i.e. SREBP-1c), and fatty acid synthase (i.e. FAS), significantly decreased, while peroxisome proliferator-activated receptor alpha (i.e. PPAR-α) and acyl-CoA oxidase 1 (i.e. ACOX1) expression significantly increased. The expressions of the inflammation-related genes, tumor necrosis factor-alpha (i.e. TNF-α), interleukin (IL)-6, and IL-1 also significantly decreased.

Conclusion

Thus, combined deer antler polysaccharides and postbiotic supplementation regulated obesity in mice, potentially by modulating lipid synthesis and inflammation-related gene expression.

Exercise as a Therapeutic Strategy for Obesity: Central and Peripheral Mechanisms

Obesity is a complex, multifactorial condition involving excessive fat accumulation due to an imbalance between energy intake and expenditure, with its global prevalence steadily rising. This condition significantly increases the risk of chronic diseases, including sarcopenia, type 2 diabetes, and cardiovascular diseases, highlighting the need for effective interventions. Exercise has emerged as a potent non-pharmacological approach to combat obesity, targeting both central and peripheral mechanisms that regulate metabolism, energy expenditure, and neurological functions. In the central nervous system, exercise influences appetite, mood, and cognitive functions by modulating the reward system and regulating appetite-controlling hormones to manage energy intake. Concurrently, exercise promotes thermogenesis in adipose tissue and regulates endocrine path-ways and key metabolic organs, such as skeletal muscle and the liver, to enhance fat oxidation and support energy balance. Despite advances in understanding exercise's role in obesity, the precise interaction between the neurobiological and peripheral metabolic pathways remains underexplored, particularly in public health strategies. A better understanding of these interactions could inform more comprehensive obesity management approaches by addressing both central nervous system influences on behavior and peripheral metabolic regulation. This review synthesizes recent insights into these roles, highlighting potential therapeutic strategies targeting both systems for more effective obesity interventions.

Vitamin D and Swimming Exercise Prevent Obesity in Rats under a High-Fat Diet via Targeting FATP4 and TLR4 in the Liver and Adipose Tissue

The prevalence of obesity has risen in the last decades, and it has caused massive health burdens on people's health, especially metabolic and cardiovascular issues. The risk of vitamin D insufficiency is increased by obesity, because adipose tissue alters both the requirements for and bioavailability of vitamin D. Exercise training is acknowledged as having a significant and long-term influence on body weight control; the favorable impact of exercise on obesity and obesity-related co-morbidities has been demonstrated via various mechanisms. The current work illustrated the effects of vitamin D supplementation and exercise on obesity induced by a high-fat diet (HFD) and hepatic steatosis in rats and explored how fatty acid transport protein-4 (FATP4) and Toll-like receptor-4 antibodies (TLR4) might be contributing factors to obesity and related hepatic steatosis. Thirty male albino rats were divided into five groups: group 1 was fed a normal-fat diet, group 2 was fed an HFD, group 3 was fed an HFD and given vitamin D supplementation, group 4 was fed an HFD and kept on exercise, and group 5 was fed an HFD, given vitamin D, and kept on exercise. The serum lipid profile adipokines, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) were analyzed, and the pathological changes in adipose and liver tissues were examined. In addition, the messenger-ribonucleic acid (mRNA) expression of FATP4 and immunohistochemical expression of TLR4 in adipose and liver tissues were evaluated. Vitamin D supplementation and exercise improved HFD-induced weight gain and attenuated hepatic steatosis, along with improving the serum lipid profile, degree of inflammation, and serum adipokine levels. The expression of FATP4 and TLR4 in both adipose tissue and the liver was downregulated; it was noteworthy that the group that received vitamin D and was kept on exercise showed also improvement in the histopathological picture of this group. According to the findings of this research, the protective effect of vitamin D and exercise against obesity and HFD-induced hepatic steatosis is associated with the downregulation of FATP4 and TLR4, as well as a reduction in inflammation.

Molecular and pharmacological aspects of piperine as a potential molecule for disease prevention and management: evidence from clinical trials

BACKGROUND

Piperine is a type of amide alkaloid that exhibits pleiotropic properties like antioxidant, anticancer, anti-inflammatory, antihypertensive, hepatoprotective, neuroprotective and enhancing bioavailability and fertility-related activities. Piperine has the ability to alter gastrointestinal disorders, drug-metabolizing enzymes, and bioavailability of several drugs. The present review explores the available clinical and preclinical data, nanoformulations, extraction process, structure-activity relationships, molecular docking, bioavailability enhancement of phytochemicals and drugs, and brain penetration properties of piperine in the prevention, management, and treatment of various diseases and disorders.

MAIN BODY

Piperine provides therapeutic benefits in patients suffering from diabetes, obesity, arthritis, oral cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Parkinson's disease, Alzheimer's disease, cerebral stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The molecular basis for the pleiotropic activities of piperine is based on its ability to regulate multiple signaling molecules such as cell cycle proteins, anti-apoptotic proteins, P-glycoprotein, cytochrome P450 3A4, multidrug resistance protein 1, breast cancer resistance protein, transient receptor potential vanilloid 1 proinflammatory cytokine, nuclear factor-κB, c-Fos, cAMP response element-binding protein, activation transcription factor-2, peroxisome proliferator-activated receptor-gamma, Human G-quadruplex DNA, Cyclooxygenase-2, Nitric oxide synthases-2, MicroRNA, and coronaviruses. Piperine also regulates multiple signaling pathways such as Akt/mTOR/MMP-9, 5'-AMP-activated protein kinase-activated NLR family pyrin domain containing-3 inflammasome, voltage-gated K+ current, PKCα/ERK1/2, NF-κB/AP-1/MMP-9, Wnt/β-catenin, JNK/P38 MAPK, and gut microbiota.

SHORT CONCLUSION

Based on the current evidence, piperine can be the potential molecule for treatment of disease, and its significance of this molecule in the clinic is discussed.

GRAPHICAL ABSTRACT

Mechanisms of weight regain

Weight regain following weight loss is frequent problem that people with obesity face. This weight recidivism is often attributed to the lack of compliance with appropriate food habits and exercise. On the contrary, it is known that body weight and fat mass are regulated by numerous physiological mechanisms, far beyond voluntary food intake and physical exercise. Thus, the aim of this paper is to review the main peripheral and central mechanisms involved in weight regain. Gut hormone secretion profiles impact upon predisposition to weight regain according to an individual variability, although it is recognised a usual pattern of compensatory changes: a reduction in anorectic hormones secretion and an increase in orexigenic hormone. These changes lead to both increased appetite and reward value of food leading to increased energye intake. In addition, resting energy expenditure after weight loss is lower than expected according to body composition changes. This gap between observed and predicted energy expenditure following weight loss is named metabolic adaptation, which has been suggested to explain partly weight regain. This complicated scenario, beyond patient motivation, makes weight regain a challenge in long-term management interventions in patients with obesity.

The Effects of Combined Physical Exercise on Serum Redox Biomarkers and Leukocyte DNA Damage of Obese Women

Obesity is usually linked to oxidative stress, which can lead to damage to biomolecules. The combination of aerobic and strength exercises seems to induce health benefits in obese individuals, but little is known about the effects of combined physical exercise on redox homeostasis and DNA damage in this population. Thus, the aim of the current study was to determine the effects of 16 weeks of combined physical exercise on biomarkers of oxidative stress and DNA damage in obese women. 17 obese women underwent 16 weeks of a combined physical training program, 3 times per week. Anthropometric and biochemical parameters, serum superoxide dismutase (SOD) and glutathione peroxidase activity, plasma 8-isoprostane levels, and DNA and chromosomal damage were evaluated before and after physical training. Combined physical exercise training decreased body weight (83.2 ± 9.6 vs. 80.2 ± 9.6 kg), body mass index (33.8 ± 3.6 vs. 32.6 ± 3.7 kg·m-2), body fat (40.2 ± 2.6 vs. 39.0 ± 3.2%), and waist circumference (99.3 ± 9.4 vs. 94.1 ± 8.8 cm), while the fat-free mass was augmented (59.9 ± 2.9 vs. 60.7 ± 3.1 kg). Moreover, blood glucose reduced (113.5 ± 29.6 vs. 107.3 ± 28.9 mg/dL) along with high-density lipoprotein (54.6 ± 18.1 vs. 59.0 ± 18.8 mg/dL), TSH (2.1 ± 1.1 vs. 2.6 ± 1.2 mIU/mL), and free T4 (0.9 ± 0.1 vs. 1.12 ± 0.2 ng/dL) increase after physical exercise training. Plasma 8-isoprostane levels (17.24 ± 7.9 vs. 29.11 ± 17.44 pg/mL) and DNA damage (34.16 ± 7.1 vs. 45.96 ± 5.8% DNA in tail) were also higher after physical training. No changes were observed in chromosomal damage levels. These results suggest that 16 weeks of combined exercise training 3 times per week is effective in reducing body fat but also increases oxidative stress and DNA damage in obese women.

Discovery of Orexant and Anorexant Agents with Indazole Scaffold Endowed with Peripheral Antiedema Activity

The endocannabinoid system represents an integrated neuronal network involved in the control of several organisms' functions, such as feeding behavior. A series of hybrids of 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (mimonabant), a well-known inverse agonist of the type-1 cannabinoid receptor (CB1), once used as an antiobesity drug, and the N-(2S)-substitutes of 1-[(4-fluorophenyl)methyl]indazole-3-carboxamide with 1-amino-3-methyl-1-oxobutane (AB-Fubinaca), 1-amino-3,3-dimethyl-1-oxobutane (ADB-Fubinaca), and 3-methylbutanoate (AMB-Fubinaca), endowed with potent agonistic activity towards cannabinoid receptors CB1 and CB2 were in solution as C-terminal amides, acids, methyl esters and N-methyl amides. These compounds have been studied by binding assays to cannabinoid receptors and by functional receptor assays, using rat brain membranes in vitro. The most active among them as an agonist, (S)-1-(2,4-dichlorobenzyl)-N-(3,3-dimethyl-1-(methylamino)-1-oxobutan-2-yl)-1H-indazole-3-carboxamide (LONI11), and an antagonist, (S)-2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamido)-3-methylbutanoic acid (LONI4), were tested in vivo in mic, to evaluate their ability to stimulate or suppress feeding behavior after intraperitoneal (i.p.) administration. For a LONI11 formalin test and a tail flick test after an administration by the subcutaneous (s.c.) and intracerebroventricular (i.c.v.) routes, respectively, were also carried out in vivo in mice to investigate the antinociceptive property at the central and peripheral levesl. We observed a significant orexant effect for LONI11 and an intense anorexant effect for (S)-methyl 2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamido)-3,3-dimethylbutanoate (LONI2) and LONI4. In zymosan-induced edema and hyperalgesia, LONI11 reduced the percent of paw volume increase and paw latency after s.c. administration, also suggesting a possible peripheral anti-inflammatory activity.

The Role of Proopiomelanocortin and α-Melanocyte-Stimulating Hormone in the Metabolic Syndrome in Psychiatric Disorders: A Narrative Mini-Review

The metabolic syndrome (MetS) comprises abdominal obesity, preclinical or full diabetes type 2, arterial hypertension, and dyslipidemia and affects a significant proportion of the general population with a remarkably higher prevalence in patients suffering from psychiatric disorders. However, studies exploring the pathogenetic link between MetS and psychiatric diseases are rare. Here, we aim to narrow this gap in knowledge by providing a narrative review on this topic that focuses on two psychiatric diseases, namely on schizophrenia and posttraumatic stress disorder (PTSD) since we assume them to be associated with two different main causalities of MetS: in schizophrenia, MetS evidently develops or aggravates in response to antipsychotic drug treatment while it assumingly develops in response to stress-induced endocrine and/or epigenetic alterations in PTSD. First, we compared the prevalences of MetS and associated pathologies (which we took from the latest meta-analyses) among different psychiatric disorders and were surprised that the prevalences of arterial hypertension and hyperglycemia in PTSD almost doubles those of the other psychiatric disorders. Next, we performed a literature search on the neurobiology of MetS and found numerous articles describing a role for proopiomelanocortin (POMC) in MetS. Thus, we concentrated further analysis on POMC and one of its downstream effector hormones, α-melanocyte-stimulating hormone (α-MSH). We found some evidence for a role of POMC in both PTSD and schizophrenia, in particular in antipsychotic-induced MetS, as well as for α-MSH in schizophrenia, but, surprisingly, no study on α-MSH in PTSD. Taken together, our synopsis reveals, first, a potential interaction between the POMC system and stress in the assumingly at least partially shared pathogenesis of psychiatric disorders and MetS, second, that modulation of the POMC system, in particular of the melanocortin 3 and 4 receptors, might be a promising target for the treatment of MetS and, third, that the DNA methylation status of POMC might speculatively be a promising biomarker for MetS in general and, possibly, in particular in the context of stress-related psychiatric conditions such as PTSD. To best of our knowledge, this is the first review on the role of the POMC system in MetS in psychiatric disorders.

Vascular targeted nanotherapeutic approach for obesity treatment

Obesity is a global epidemic that poses a serious health concern due to it being a risk factor for life-threatening chronic diseases, such as type 2 diabetes, cancer, and cardiovascular diseases. Pharmacotherapy remains the mainstay for the management of obesity; however, its usefulness is limited due to poor drug efficacy, non-specificity and toxic side effects. Therefore, novel approaches that could provide insights into obesity and obesity-associated diseases as well as development of novel anti-obesity treatment modalities or improvement on the existing drugs are necessary. While the ideal treatment of obesity should involve early intervention in susceptible individuals, targeted nanotherapy potentially provides a fresh perspective that might be better than the current conventional therapies. Independent studies have shown improved drug efficacy by using prohibitin (PHB)-targeted therapy in obese rodents and non-human primates, thus providing a proof of concept that targeted nanotherapy can be a feasible treatment for obesity. This review presents a brief global survey of obesity, its impact on human health, its current treatment and their limitations, and the role of angiogenesis and PHB in the development of obesity. Finally, the role and potential use of nanotechnology coupled with targeted drug delivery in the treatment of obesity are discussed.

Ghrelin, a gastrointestinal hormone, regulates energy balance and lipid metabolism

Ghrelin, an acylated peptide hormone of 28 amino acids, is an endogenous ligand of the released growth hormone secretagogue receptor (GHSR). Ghrelin has been isolated from human and rat stomach and is also detected in the hypothalamic arcuate nucleus. Ghrelin receptor is primarily located in the neuropeptide Y and agouti-related protein neurons. Many previous studies have shown that ghrelin and GHSR are involved in the regulation of energy homeostasis, and its administration can increase food intake and body weight gain. AMP-activated protein kinase is activated by ghrelin in the hypothalamus, which contributes to lower intracellular long-chain fatty acid level. Ghrelin appears to modulate the response to food cues via a neural network involved in the regulation of feeding and in the appetitive response to food cues. It also increases the response of brain areas involved in visual processing, attention, and memory to food pictures. Ghrelin is also an important factor linking the central nervous system with peripheral tissues that regulate lipid metabolism. It promotes adiposity by the activation of hypothalamic orexigenic neurons and stimulates the expression of fat storage-related proteins in adipocytes. Meanwhile, ghrelin exerts direct peripheral effects on lipid metabolism, including increase in white adipose tissue mass, stimulation of lipogenesis in the liver, and taste sensitivity modulation.

Use of Simplified Molecular Input Line Entry System and molecular graph based descriptors in prediction and design of pancreatic lipase inhibitors

Aim: The inhibition of pancreatic lipase (PL) enzyme is the most explored strategy for the treatment of obesity. The present study describes the development of quantitative structure–activity relationship (QSAR) models for a diverse set of 293 PL inhibitors by means of the Monte Carlo optimization technique. Methodology & results: The hybrid optimal descriptors were used to build QSAR models with three subsets of three splits. The developed QSAR models were further validated with corresponding external sets. The best QSAR model has the following statistical particulars: R2 = 0.752, Q LOO 2 = 0 . 736 for the test set and R2 = 0.768, Q F 1 2 = 0 . 628 , Q F 2 2 = 0 . 621 for the validation set. Conclusion: The developed QSAR models were robust, stable and predictive and led to the design of novel PL inhibitors.

Central and peripheral control of food intake

The maintenance of the body weight at a stable level is a major determinant in keeping the higher animals and mammals survive. Th e body weight depends on the balance between the energy intake and energy expenditure. Increased food intake over the energy expenditure of prolonged time period results in an obesity. Th e obesity has become an important worldwide health problem, even at low levels. The obesity has an evil effect on the health and is associated with a shorter life expectancy. A complex of central and peripheral physiological signals is involved in the control of the food intake. Centrally, the food intake is controlled by the hypothalamus, the brainstem, and endocannabinoids and peripherally by the satiety and adiposity signals. Comprehension of the signals that control food intake and energy balance may open a new therapeutic approaches directed against the obesity and its associated complications, as is the insulin resistance and others. In conclusion, the present review summarizes the current knowledge about the complex system of the peripheral and central regulatory mechanisms of food intake and their potential therapeutic implications in the treatment of obesity.

Anamorelin hydrochloride in the treatment of cancer anorexia-cachexia syndrome: design, development, and potential place in therapy

Cancer anorexia–cachexia syndrome (CACS) is a complex and largely untreatable paraneoplastic complication common in advanced cancer. It is associated with profoundly deleterious effects on quality of life and survival. Since its discovery over a decade ago, anamorelin hydrochloride (anamorelin), a mimetic of the growth hormone secretagogue ghrelin, has shown considerable promise in ameliorating components of CACS when administered to patients with advanced cancer, including loss of lean body mass and reversal of anorexia. This review summarizes the development of anamorelin and its safety and efficacy in clinical investigations. The potential future role of anamorelin in treating CACS is also discussed.

The cellular and molecular bases of leptin and ghrelin resistance in obesity

Obesity, a major risk factor for the development of diabetes mellitus, cardiovascular diseases and certain types of cancer, arises from a chronic positive energy balance that is often due to unlimited access to food and an increasingly sedentary lifestyle on the background of a genetic and epigenetic vulnerability. Our understanding of the humoral and neuronal systems that mediate the control of energy homeostasis has improved dramatically in the past few decades. However, our ability to develop effective strategies to slow the current epidemic of obesity has been hampered, largely owing to the limited knowledge of the mechanisms underlying resistance to the action of metabolic hormones such as leptin and ghrelin. The development of resistance to leptin and ghrelin, hormones that are crucial for the neuroendocrine control of energy homeostasis, is a hallmark of obesity. Intensive research over the past several years has yielded tremendous progress in our understanding of the cellular pathways that disrupt the action of leptin and ghrelin. In this Review, we discuss the molecular mechanisms underpinning resistance to leptin and ghrelin and how they can be exploited as targets for pharmacological management of obesity.

The impact of duration on effectiveness of exercise, the implication for periodization of training and goal setting for individuals who are overfat, a meta-analysis

Given the assumption that all methods of exercise, e.g., endurance (ET), resistance (RT), or combination of both (E+R), can induce a beneficial effect size (ES) for changes in body composition and health status of individuals who are overfat. Thus the aim and purpose of this study is to evaluate the current body of knowledge to address the question as to the impact that the duration of exercise has on its relative effectiveness for inducing health and body compositional changes in individuals who are overfat to assist with developing periodized exercise protocols and establishing short and long term goals. A tiered meta-analysis of 92-studies and 200-exercise groupings were used for establishing pooled ES within and between groupings based on the increments of 4-week of duration and study designs of ≤8, 9-16, 17-23, 24-36, and ≥36 weeks. Analysis based on random-effect of response indicates a continuum of effectiveness within and between ET, RT and E+R based on duration. Where beneficial effectiveness is not indicated for any measures until after 8-weeks of continuous training with progressive effectiveness being noted in changes to cardiorespiratory fitness, inflammatory cytokines, and alteration of metabolic status from 12-weeks through 32-weeks of continuous training. Results indicate a greater ES for RT and E+R versus ET early in intervention that equalizes with longer durations. Supporting the use of RT and E+R within a periodized program. And secondarily, goals should be established first on performance gains and second body composition or health status modifications for the individual who is overfat.

Metabolism and Mental Illness

Over the past century, overwhelming evidence has emerged pointing to the hypothalamus of the central nervous system (CNS) as a crucial regulator of systemic control of metabolism, including appetite and feeding behavior. Appetite (or hunger) is a fundamental driver of survival, involving complex behaviors governed by various parts of the brain, including the cerebral cortex. Here, we provide an overview of basic metabolic principles affecting the CNS and discuss their relevance to physiological and pathological conditions of higher brain functions. These novel perspectives may well provide new insights into future research strategies to facilitate the development of novel therapies for treating mental illness.

Medicinal Plants Traditionally Used for Treatment of Obesity and Diabetes Mellitus - Screening for Pancreatic Lipase and α-Amylase Inhibition

In order to find new pancreatic lipase (PL) and α-amylase inhibitors from natural sources for the treatment of obesity and related diseases as diabetes mellitus II, 23 medicinal plants with weight-reducing, serum glucose-reducing or related potential were investigated. Methanolic and water extracts of the plants were evaluated by using two in vitro test systems. Our findings have shown that the methanolic extract of Hibiscus sabdariffa L. (Malvaceae) showed high inhibitory activities to PL (IC50 : 35.8 ± 0.8 µg/mL) and α-amylase (IC50 : 29.3 ± 0.5 µg/mL). Furthermore, the methanolic extract of Tamarindus indica L. (Leguminosae) showed a high anti-lipase (IC50 : 152.0 ± 7.0 µg/mL) and the aqueous extract a high anti-amylase (IC50 : 139.4 ± 9.0 µg/mL) activity. This work provides a priority list of interesting plants for further study with respect to the treatment of obesity and associated diseases.

Intestinal FXR agonism promotes adipose tissue browning and reduces obesity and insulin resistance

The systemic expression of the bile acid (BA) sensor farnesoid X receptor (FXR) has led to promising new therapies targeting cholesterol metabolism, triglyceride production, hepatic steatosis and biliary cholestasis. In contrast to systemic therapy, bile acid release during a meal selectively activates intestinal FXR. By mimicking this tissue-selective effect, the gut-restricted FXR agonist fexaramine (Fex) robustly induces enteric fibroblast growth factor 15 (FGF15), leading to alterations in BA composition, but does so without activating FXR target genes in the liver. However, unlike systemic agonism, we find that Fex reduces diet-induced weight gain, body-wide inflammation and hepatic glucose production, while enhancing thermogenesis and browning of white adipose tissue (WAT). These pronounced metabolic improvements suggest tissue-restricted FXR activation as a new approach in the treatment of obesity and metabolic syndrome.

Effect of broccoli phytochemical extract on release of fatty acids from salmon muscle and salmon oil during in vitro digestion

The aim of the present work was to study the effect of a broccoli phytochemical extract (Br-ex) on the release of fatty acids (FA) from salmon muscle (SM) and salmon oil (SO) duringin vitrodigestion.

Obesity pharmacotherapy: current perspectives and future directions

The rising tide of obesity and its related disorders is one of the most pressing health concerns worldwide, yet existing medicines to combat the problem are disappointingly limited in number and effectiveness. Recent advances in mechanistic insights into the neuroendocrine regulation of body weight have revealed an expanding list of molecular targets for novel, rationally designed antiobesity pharmaceutical agents. Antiobesity drugs act via any of four mechanisms: 1) decreasing energy intake, 2) increasing energy expenditure or modulating lipid metabolism, 3) modulating fat stores or adipocyte differentiation, and 4) mimicking caloric restriction. Various novel drug candidates and targets directed against obesity are currently being explored. A few of them are also in the later phases of clinical trials. This review discusses the development of novel antiobesity drugs based on current understanding of energy homeostasis

The investigation of leptin and hypothalamic neuropeptides role in first attack psychotic male patients: olanzapine monotherapy

The mechanism underlying the weight gain due to treatment with olanzapine and other second generation antipsychotics has not been fully understood. To examine olanzapine's weight gain effects, we accepted first attack psychotic patients with no medication (pre-treatment) (n=22) and the healthy control group (n=26) in this study. After patientś diagnosis, they were hospitalized and then treated for four weeks with olanzapine (post-treatment). We used case-control association design to test body mass index (BMI) and biochemical changes in each group. We also investigated peripheral leptin and neuropeptides/hormones namely, pro-opiomelanocortin (POMC), cocaine and amphetaime regulated transcript (CART), and neuropeptide Y (NPY) levels. These neuropeptides which are synthesized/secreted from arcuate nucleus of hypothalamus affect food intake and therefore, body weight. After 4 weeks of olanzapine treatment; BMI (body mass index), waist circumference, blood triglyceride, total cholesterol, and very low density lipoprotein (VLDL) levels were increased significantly in patients compared to their pre-treatment baseline. In pre-treatment, patients' NPY levels were significantly lower while α-MSH, the anorexigenic product of POMC levels were significantly higher vs. control. Both leptin and NPY levels were significantly increased in patients after the treatment but the NPY levels were also significantly lower in post-treatment vs. the control group. The CART levels did not change after the treatment. We may presume that the antagonist effect of olanzapine on the serotonin (5HT2CR and 5HT1BR) receptors of the arcuate hypothalamic neurons may be a basis for a deregulation of the neurohormones secretion.

The effects of exercise modalities on adiposity in obese rats

OBJECTIVE

The aim of the present study was to evaluate the effect of both swimming and resistance training on tumor necrosis factor-alpha and interleukin-10 expression, adipocyte area and lipid profiles in rats fed a high-fat diet.

METHODS

The study was conducted over an eight-week period on Wistar adult rats, who were divided into six groups as follows (n = 10 per group): sedentary chow diet, sedentary high-fat diet, swimming plus chow diet, swimming plus high-fat diet, resistance training plus chow diet, and resistance training plus high-fat diet. Rats in the resistance training groups climbed a vertical ladder with weights on their tails once every three days. The swimming groups swam for 60 minutes/day, five days/week.

RESULTS

The high-fat diet groups had higher body weights, a greater amount of adipose tissue, and higher tumor necrosis factor-alpha expression in the visceral adipose tissue. Furthermore, the high-fat diet promoted a negative change in the lipid profile. In the resistance training high-fat group, the tumor necrosis factor-alpha expression was lower than that in the swimming high-fat and sedentary high-fat groups. Moreover, smaller visceral and retroperitoneal adipocyte areas were found in the resistance training high-fat group than in the sedentary high-fat group. In the swimming high-fat group, the tumor necrosis factor-alpha expression was lower and the epididymal and retroperitoneal adipocyte areas were smaller compared with the sedentary high-fat group.

CONCLUSION

The results showed that both exercise modalities improved the lipid profile, adiposity and obesity-associated inflammation in rats, suggesting their use as an alternative to control the deleterious effects of a high-fat diet in humans.

In vitro inhibitory effect on pancreatic lipase activity of subfractions from ethanol extracts of fermented Oats (Avena sativa L.) and synergistic effect of three phenolic acids

The purpose of the present work is to study the pancreatic lipase inhibitory effects of different subfractions (n-hexane, ethyl acetate (EA), n-butanol, and water) from ethanol extracts of nonfermented and fungi-fermented oats and to delineate the interactions of three primary phenolic acids in the EA subfractions. The EA subfraction showed the highest inhibitory effect on pancreatic lipase activity at 1.5 mg/mL compared to the other subfractions, regardless of whether the oats were fermented. Meanwhile, both of the EA subfractions of two fungi-fermented oats demonstrated more effective inhibitory activity than that of nonfermented oats. A positive correlation between the total phenolics content and inhibitory activity was found. The inhibitory ability of the EA subfraction from nonfermented or fermented oats also displayed a dose-dependent effect. The standards of caffeic, ferulic, and p-coumaric acids, mainly included in EA subfractions of fermented oats, also displayed a dose-dependent inhibitory effect. A synergistic effect of each binary combination of p-coumaric, ferulic, and caffeic acids was observed, especially at 150.0 μg/mL. Those results indicate that fungi-fermented oats have a more effective inhibitory ability on pancreatic lipase and polyphenols may be the most effective component and could be potentially used for dietary therapy of obesity.

Nicotine induces negative energy balance through hypothalamic AMP-activated protein kinase

Smokers around the world commonly report increased body weight after smoking cessation as a major factor that interferes with their attempts to quit. Numerous controlled studies in both humans and rodents have reported that nicotine exerts a marked anorectic action. The effects of nicotine on energy homeostasis have been mostly pinpointed in the central nervous system, but the molecular mechanisms controlling its action are still not fully understood. The aim of this study was to investigate the effect of nicotine on hypothalamic AMP-activated protein kinase (AMPK) and its effect on energy balance. Here we demonstrate that nicotine-induced weight loss is associated with inactivation of hypothalamic AMPK, decreased orexigenic signaling in the hypothalamus, increased energy expenditure as a result of increased locomotor activity, increased thermogenesis in brown adipose tissue (BAT), and alterations in fuel substrate utilization. Conversely, nicotine withdrawal or genetic activation of hypothalamic AMPK in the ventromedial nucleus of the hypothalamus reversed nicotine-induced negative energy balance. Overall these data demonstrate that the effects of nicotine on energy balance involve specific modulation of the hypothalamic AMPK-BAT axis. These targets may be relevant for the development of new therapies for human obesity.

Decreased body weight and hepatic steatosis with altered fatty acid ethanolamide metabolism in aged L-Fabp -/- mice

The tissue-specific sources and regulated production of physiological signals that modulate food intake are incompletely understood. Previous work showed that L-Fabp(-/-) mice are protected against obesity and hepatic steatosis induced by a high-fat diet, findings at odds with an apparent obesity phenotype in a distinct line of aged L-Fabp(-/-) mice. Here we show that the lean phenotype in L-Fabp(-/-) mice is recapitulated in aged, chow-fed mice and correlates with alterations in hepatic, but not intestinal, fatty acid amide metabolism. L-Fabp(-/-) mice exhibited short-term changes in feeding behavior with decreased food intake, which was associated with reduced abundance of key signaling fatty acid ethanolamides, including oleoylethanolamide (OEA, an agonist of PPARα) and anandamide (AEA, an agonist of cannabinoid receptors), in the liver. These reductions were associated with increased expression and activity of hepatic fatty acid amide hydrolase-1, the enzyme that degrades both OEA and AEA. Moreover, L-Fabp(-/-) mice demonstrated attenuated responses to OEA administration, which was completely reversed with an enhanced response after administration of a nonhydrolyzable OEA analog. These findings demonstrate a role for L-Fabp in attenuating obesity and hepatic steatosis, and they suggest that hepatic fatty acid amide metabolism is altered in L-Fabp(-/-) mice.

Appetite regulation and weight control: the role of gut hormones

The overwhelming increase in the prevalence of overweight and obesity in recent years represents one of the greatest threats to the health of the developed world. Among current treatments, however, gastrointestinal (GI) surgery remains the only approach capable of achieving significant weight loss results with long-term sustainability. As the obesity prevalence approaches epidemic proportions, the necessity to unravel the mechanisms regulating appetite control has garnered significant attention. It is well known that physical activity and food intake regulation are the two most important factors involved in body weight control. To regulate food intake, the brain must alter appetite. With this realization has come increased efforts to understand the intricate interplay between gut hormones and the central nervous system, and the role of these peptides in food intake regulation through appetite modulation. This review discusses the central mechanisms involved in body weight regulation and explores a suite of well characterized and intensely investigated anorexigenic and orexigenic gut hormones. Their appetite-regulating capabilities, post-GI surgery physiology and emerging potential as anti-obesity therapeutics are then reviewed.

Plasma proteomic analysis in obese and overweight prepubertal children

BACKGROUND

Childhood obesity represents one of the most challenging health problems of our century and is associated with significant morbidity and mortality in adult life. Proteomics is a large-scale analysis of proteins, which provides, information on protein expression levels, post-translational modifications, subcellular localization and interactions.

OBJECTIVE

To investigate whether obesity in childhood is associated with alterations in plasma protein expression profiles.

METHODS

Plasma samples from 10 obese [age: 10·75 ± 0·16 year; body mass index (BMI): 27·50 ± 0·69 kg m(-2) ], 10 overweight (age: 10·54 ± 0·1 year; BMI: 21·88 ± 0·28 kg m(-2) ) and 10 normal-weight (age: 10·89 ± 0·19 year; BMI: 18·34 ± 0·42kg m(-2) ) prepubertal boys were subjected to protein fractionation and analysed by two-dimensional electrophoresis, followed by protein identification using matrix-assisted laser desorption time-of-flight mass spectrometry. Fasting plasma glucose and serum insulin, lipid and apolipopoprotein concentrations were determined in all subjects.

RESULTS

The expression of apolipoprotein (Apo) A-I (ApoA-I) was significantly lower in obese and overweight children compared with children of normal BMI (P < 0·05). The expression of ApoE was significantly lower in overweight compared with normal-weight children (P < 0·05), while that of ApoA-IV was significantly higher in obese children compared with their normal counterparts (P < 0·01). Serum ApoA-I concentrations were significantly lower in obese (147 ± 4·27mg dL(-1) ) and overweight (145·5 ± 9·65mg dL(-1) ) than in normal-weight (157 ± 8·77mg dL(-1) ; P = 0·036) children.

CONCLUSIONS

Obese and overweight prepubertal children demonstrated prominent alterations in the expression of plasma apolipoproteins compared with their normal counterparts. Low ApoA-I plasma expression levels and serum concentrations in obesity might be present in childhood before any significant alterations in total or high-density lipoprotein-cholesterol concentrations are documented. We recommend that serum ApoA-I concentrations are determined in all overweight and obese children.

Neuroprotective actions of ghrelin and growth hormone secretagogues

The brain incorporates and coordinates information based on the hormonal environment, receiving information from peripheral tissues through the circulation. Although it was initially thought that hormones only acted on the hypothalamus to perform endocrine functions, it is now known that they in fact exert diverse actions on many different brain regions including the hypothalamus. Ghrelin is a gastric hormone that stimulates growth hormone secretion and food intake to regulate energy homeostasis and body weight by binding to its receptor, growth hormone secretagogues–GH secretagogue-receptor, which is most highly expressed in the pituitary and hypothalamus. In addition, ghrelin has effects on learning and memory, reward and motivation, anxiety, and depression, and could be a potential therapeutic agent in neurodegenerative disorders where excitotoxic neuronal cell death and inflammatory processes are involved.

Efficacy of lifestyle interventions in physical health management of patients with severe mental illness

Awareness of the importance of maintaining physical health for patients with severe mental illnesses has recently been on the increase. Although there are several elements contributing to poor physical health among these patients as compared with the general population, risk factors for cardiovascular disease such as smoking, diabetes mellitus, hypertension, dyslipidemia, metabolic syndrome, and obesity are of particular significance due to their relationship with mortality and morbidity. These patients present higher vulnerability to cardiovascular risk factors based on several issues, such as genetic predisposition to certain pathologies, poor eating habits and sedentary lifestyles, high proportions of smokers and drug abusers, less access to regular health care services, and potential adverse events during pharmacological treatment. Nevertheless, there is ample scientific evidence supporting the benefits of lifestyle interventions based on diet and exercise designed to minimize and reduce the negative impact of these risk factors on the physical health of patients with severe mental illnesses.

Effect of piperine in the regulation of obesity-induced dyslipidemia in high-fat diet rats

Objective:

The present study was undertaken to explore the effect of piperine in obesity-induced dyslipidemia.

Materials and Methods:

Male Sprague Dawley rats were fed high-fat diet (HFD) for the first eight weeks, to develop obesity-induced dyslipidemia. Later on piperine (40 mg / kg) and sibutramine (5 mg / kg) were administered for three weeks along with the continuation of HFD to two separate groups, which served as the test and standard groups, respectively. Body weight, food intake, serum triglyceride, total cholesterol, LDL, VLDL, and HDL were measured at the end of the fourth, eighth (before treatment), and eleventh (after treatment) week, while the fat mass was measured at the end of the eleventh week in the normal, HFD-control, test, and standard groups.

Results:

Supplementing piperine with HFD significantly reduced not only body weight, triglyceride, total cholesterol, LDL, VLDL, and fat mass, but also increased the HDL levels, with no change in food intake.

Conclusion:

The above results suggest that piperine possesses potential fat reducing and lipid lowering effects, without any change in food appetite, at a small dose of 40 mg / kg. The mechanism of action for such an activity needs to be determined. However, looking to structural similarity with the presently known Melanocortin-4 (MC-4) agonists, involvement of MC-4 receptors in its activity can be guessed.

Lifestyle factors and ghrelin: critical review and implications for weight loss maintenance

Ghrelin, the only known appetite-stimulating hormone in humans, may be one factor involved in increased appetite, cravings and food intake following weight loss. Innovative strategies for suppressing ghrelin and decreasing appetite during weight loss maintenance are needed. Recent research has highlighted relationships between ghrelin, stress and lifestyle factors. The purposes of the current review are to (i) describe the current status of knowledge about ghrelin and lifestyle factors; (ii) critically examine research in this area, highlighting inconsistencies and methodological issues and (iii) discuss future directions and implications for obesity treatment. Based on Literature search using PsycINFO and Medline databases, we reviewed experimental studies on relationships between ghrelin, stress, exercise and sleep. Ghrelin levels are positively related to stress hormones, and stress management interventions including exercise and sleep may help to reduce acylated ghrelin and corresponding appetite. Behavioural interventions may offer a practical, cost-effective alternative for reducing or stabilizing ghrelin levels after initial weight loss. Adding behavioural techniques designed to reduce ghrelin to traditional weight loss maintenance protocols may help individuals to maintain weight loss. Future directions for investigating relationships between ghrelin and behavioural factors, examining the efficacy of behavioural programmes in reducing ghrelin and improving weight loss maintenance are discussed.

Hypoglycemia complicating bariatric surgery: incidence and mechanisms

PURPOSE OF REVIEW

To discuss the clinical scope and frequency of hypoglycemia following bariatric surgery, and possible mechanisms mediating this potentially life-threatening complication.

RECENT FINDINGS

Consequent to the rise in severe obesity, bariatric surgery is being performed with ever increasing frequency. Although data continue to accumulate supporting the myriad metabolic and other health benefits of bariatric surgery, there are also concerns regarding the mounting reports of severe hypoglycemia. The problem is particularly significant following gastric bypass, with the first concerns raised in 2005 following a case series reported from the Mayo Clinic. A Swedish nationwide cohort study recently estimated the frequency of this complication suggesting it was less than 1%. Hypotheses regarding the mechanism(s) by which hypoglycemia arise following gastric bypass range from beta cell expansion to altered beta cell function as well as nonbeta cell factors.

SUMMARY

Regardless of the incidence, the severity of hypoglycemia for select patients following gastric bypass necessitates that we strive to gain a better understanding of the underlying mechanisms. With such knowledge, those patients at greater risk for this complication might be identified preoperatively, and decisions regarding their surgical management optimized to reduce this risk.

The hungry stomach: physiology, disease, and drug development opportunities

During hunger, a series of high-amplitude contractions of the stomach and small intestine (phase III), which form part of a cycle of quiescence and contractions (known as the migrating motor complex, MMC), play a "housekeeping" role prior to the next meal, and may contribute toward the development of hunger. Several gastrointestinal (GI) hormones are associated with phase III MMC activity, but currently the most prominent is motilin, thought to at least partly mediate phase III contractions of the gastric MMC. Additional GI endocrine and neuronal systems play even more powerful roles in the development of hunger. In particular, the ghrelin-precursor gene is proving to have a complex physiology, giving rise to three different products: ghrelin itself, which is formed from a post-translational modification of des-acyl-ghrelin, and obestatin. The receptors acted on by des-acyl-ghrelin and by obestatin are currently unknown but both these peptides seem able to exert actions which oppose that of ghrelin, either indirectly or directly. An increased understanding of the actions of these peptides is helping to unravel a number of different eating disorders and providing opportunities for the discovery of new drugs to regulate dysfunctional gastric behaviors and appetite. To date, ghrelin and motilin receptor agonists and antagonists have been described. The most advanced are compounds which activate the ghrelin and motilin receptors which are being progressed for disorders associated with gastric hypomotility.

Effects of hyperinsulinemia on lipolytic function of three-dimensional adipocyte/endothelial co-cultures

The increased incidence of both type 2 diabetes mellitus and obesity has prompted the need to develop physiologically relevant adipose tissue models for controlled study of both normal and diseased adipose functions. Insulin resistance, characteristic of both type 2 diabetes mellitus and obesity, is often preceded by hyperinsulinemia. We propose here a three-dimensional (3D) co-culture adipose tissue model to study the effects of high insulin exposure, which enabled the study of physiological cell responses to hyperinsulinemic conditions. Two-dimensional adipocyte studies were initially conducted to establish a baseline control in which insulin levels were established. Adipocytes and endothelial cells were subsequently co-cultured on 3D porous silk fibroin scaffolds in normal or high insulin concentrations, and their physiological responses were assessed with respect to lipogenesis and lipolysis. High insulin levels stimulated both an increase in triglyceride accumulation and a decrease in lipolysis levels compared to that of normal insulin conditions. In contrast, adipocyte monocultures did not exhibit any differences between insulin levels. The ability of this 3D system to elicit physiological responses to hyperinsulinemia in co-culture serves as a significant step forward in adipose tissue engineering. The development of physiologically relevant 3D in vitro adipose tissue models presents promise for the study of disease mechanisms as well as in assessing therapeutic treatments.

Leptin-based therapeutics

Leptin, a pluripotent adipokine, has been discovered as a hormone controlling energy balance in hypothalamic neuroendocrine centers. In addition, recent studies provided ample evidence that leptin can be produced by cells other than adipocytes, and that the hormone can regulate many physiological processes other than energy balance and appetite. In this context, it is not surprising that both leptin excess as well as leptin insufficiency have been implicated in various pathologies. Consequently, despite initially disappointing results with recombinant leptin as the drug for obesity management, new leptin receptor modifiers have been developed and emerged as potential treatment modalities for numerous metabolic, immunological and neoplastic diseases. The major focus of this paper is a systematic review of current experimental leptin-based therapies, including pharmacological advantages and limitations of each prodrug category.

Gut hypertrophy after gastric bypass is associated with increased glucagon-like peptide 2 and intestinal crypt cell proliferation

OBJECTIVE

We aimed to determine changes in crypt cell proliferation and glucagon-like peptide-2 (GLP-2) in rodents and man after Roux-en-Y gastric bypass (RYGB).

SUMMARY OF BACKGROUND DATA

Roux-en-Y gastric bypass results in sustained weight loss and reduced appetite with only mild gastrointestinal side effects. Glucagon-like peptide-2 released from intestinal l-cells after nutrient intake stimulates intestinal crypt cell proliferation and mitigates the effects of gut injury.

METHODS

Wistar rats underwent either RYGB (n = 6) or sham procedure (n = 6) and plasma GLP-2, GLP-1, and gut hormone peptide YY (PYY) were measured after 23 days. Biopsies from the terminal ileum were stained using the antibody to Ki67, which detects cyclins and hence demonstrates cells in the S-phase of the cell cycle. The total number of cells, number of mitosis, and number of labeled cells per crypt were counted. Obese patients (n = 6) undergoing RYGB were evaluated following a 420 kcal meal preoperatively, and 1, 3, 6, 12, and 24 months later for responses in l-cell products such as GLP-2, GLP-1, total PYY, and PYY3-36.

RESULTS

Rat GLP-2 levels after RYGB were elevated 91% above sham animals (P = 0.02). At necropsy, mitotic rate (P < 0.001) and cells positive for the antibody Ki67 (P < 0.001) were increased, indicating crypt cell proliferation. Human GLP-2 after RYGB reached a peak at 6 months of 168% (P < 0.01) above preoperative values. Area under the curve for GLP-1 (P < 0.0001), total PYY (P < 0.01), and PYY3-36 (P < 0.05) responses increased progressively over 24 months.

CONCLUSIONS

RYGB leads to increased GLP-2 and mucosal crypt cell proliferation. Other gut hormones from l-cells remain elevated for at least 2 years in humans. These findings may account for the restoration of the absorptive surface area of the gut, which limits malabsorption and contributes to the long-term weight loss after RYGB.