Pharmacotherapy for the treatment of obesity

Chronic Exposure to High Fat Diet Affects the Synaptic Transmission That Regulates the Dopamine Release in the Nucleus Accumbens of Adolescent Male Rats

Obesity is a pandemic caused by many factors, including a chronic excess in hypercaloric and high-palatable food intake. In addition, the global prevalence of obesity has increased in all age categories, such as children, adolescents, and adults. However, at the neurobiological level, how neural circuits regulate the hedonic consumption of food intake and how the reward circuit is modified under hypercaloric diet consumption are still being unraveled. We aimed to determine the molecular and functional changes of dopaminergic and glutamatergic modulation of nucleus accumbens (NAcc) in male rats exposed to chronic consumption of a high-fat diet (HFD). Male Sprague-Dawley rats were fed a chow diet or HFD from postnatal day (PND) 21 to 62, increasing obesity markers. In addition, in HFD rats, the frequency but not amplitude of the spontaneous excitatory postsynaptic current is increased in NAcc medium spiny neurons (MSNs). Moreover, only MSNs expressing dopamine (DA) receptor type 2 (D₂) increase the amplitude and glutamate release in response to amphetamine, downregulating the indirect pathway. Furthermore, NAcc gene expression of inflammasome components is increased by chronic exposure to HFD. At the neurochemical level, DOPAC content and tonic dopamine (DA) release are reduced in NAcc, while phasic DA release is increased in HFD-fed rats. In conclusion, our model of childhood and adolescent obesity functionally affects the NAcc, a brain nucleus involved in the hedonic control of feeding, which might trigger addictive-like behaviors for obesogenic foods and, through positive feedback, maintain the obese phenotype.

Exploring the wider benefits of semaglutide treatment in obesity: insight from the STEP program

Obesity negatively impacts patients' health-related quality of life (QOL) and is associated with a range of complications such as type 2 diabetes (T2D), cardiovascular disease, and sleep apnea, alongside decreased physical function, mobility, and control of eating. The Semaglutide Treatment Effect in People with obesity (STEP) trials compared once-weekly subcutaneous semaglutide 2.4 mg with placebo in adults with overweight or obesity, with or without T2D. This article reviews the effects of semaglutide 2.4 mg on QOL, control of eating, and body composition. Weight-related QOL was assessed using the Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT), and health-related QOL was assessed with the 36-item Short Form Health Survey version 2 (SF-36v2®). Control of eating was evaluated using the Control of Eating questionnaire in a subgroup of participants in one trial. Body composition was evaluated via dual-energy x-ray absorptiometry in another trial, in a subgroup of participants with a body mass index of ≤40 kg/m². All IWQOL-Lite-CT scores (Physical Function, Physical, Psychosocial, and Total Score) improved with semaglutide 2.4 mg significantly more than with placebo. Across the trials, changes in SF-36v2 scores were generally in favor of semaglutide versus placebo. There were significant improvements in all Control of Eating questionnaire domains (craving control, craving for savory, craving for sweet, and positive mood) up to week 52 with semaglutide treatment versus placebo, with improvements in craving control and craving for savory remaining significantly different at week 104. Body composition findings showed that reductions in total fat mass were greater with semaglutide versus placebo. These findings highlight the wider benefits that patients can experience with once-weekly subcutaneous semaglutide 2.4 mg, in addition to weight loss, including improvements in patients' wellbeing and ability to perform daily activities. Taken together, these are important considerations for primary care when incorporating pharmacotherapy for weight management.

Beneficial Effects of Early Time-Restricted Feeding on Metabolic Diseases: Importance of Aligning Food Habits with the Circadian Clock

The importance of metabolic health is a major societal concern due to the increasing prevalence of metabolic diseases such as obesity, diabetes, and various cardiovascular diseases. The circadian clock is clearly implicated in the development of these metabolic diseases. Indeed, it regulates physiological processes by hormone modulation, thus helping the body to perform them at the ideal time of day. Since the industrial revolution, the actions and rhythms of everyday life have been modified and are characterized by changes in sleep pattern, work schedules, and eating habits. These modifications have in turn lead to night shift, social jetlag, late-night eating, and meal skipping, a group of customs that causes circadian rhythm disruption and leads to an increase in metabolic risks. Intermittent fasting, especially the time-restricted eating, proposes a solution: restraining the feeding window from 6 to 10 h per day to match it with the circadian clock. This approach seems to improve metabolic health markers and could be a therapeutic solution to fight against metabolic diseases. This review summarizes the importance of matching life habits with circadian rhythms for metabolic health and assesses the advantages and limits of the application of time-restricted fasting with the objective of treating and preventing metabolic diseases.

Protective effect of Curcuma amada acetone extract against high-fat and high-sugar diet-induced obesity and memory impairment

Objectives: Curcuma amada Roxb. (Mango ginger) was evaluated for anti-obesity, anti-amnesic and neuroprotection using high-fat and high-sugar diet (HFHS)-induced obesity and cognitive impairment in rats. Methods: Animals were exposed to HFHS diet to evaluate lipid parameters and subjected to Y maze test and Pole climbing test to evaluate the memory. In addition, oxidative stress parameters, acetyl cholinesterase activity (AChE), neurochemicals and histopathology were assessed in the brain. Results: HFHS diet led to increased body weight and lipid parameters (total cholesterol, low-density lipoprotein [LDL], and very low-density lipoprotein [VLDL], triglycerides [TG]) but not high-density lipoprotein (HDL). Elevated serum glutamate oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT), oxidative biomarker, decreased enzymatic and non-enzymatic antioxidants, Acetylcholinesterase (AChE) activity and reduced percentage of spontaneous alternation behaviour (% SAB in Y-maze test) as well as reduced serotonin and dopamine levels and neurodegeneration were observed in HFHS diet-fed rats. Curcuma amada (CAAE1, 100 mg/kg and CAAE2, 300 mg/kg) treatment to HFHS diet-fed rats (21 days after HFHS diet feeding alone) showed dose-dependent activity and ameliorated the HFHS diet-induced alterations in lipid parameters related to obesity, hepatological parameters, memory, oxidative stress, neurochemicals and neurodegeneration. Furthermore, 300 mg/kg of C. amada (CAAE2) augmented the memory by inhibiting acetylcholinesterase (AChE) activity; it also ameliorated the effect of antioxidants such as glutathione, superoxide dismutase (SOD), and total thiol and mitigated the effect of malondialdehyde (MDA). CAAE2 also controlled the level of dopamine and serotonin and reduced the neurodegeneration in the hippocampus CA1 region. Discussion: The results of the present study indicated that treatment with C. amada 300 mg/kg (CAAE2) attenuated the HFHS diet-induced obesity, memory loss, oxidative stress, and neurodegeneration. These study results indicated that the administration of C. amada offers a potential treatment option for obesity and memory loss, and it requires further preclinical and clinical evaluations.

Semaglutide 2.4 mg for the Treatment of Obesity: Key Elements of the STEP Trials 1 to 5

OBJECTIVE

The obesity epidemic is a public health concern, warranting further research into pharmacological treatments for weight management (WM) as an adjunct to lifestyle interventions. The Semaglutide Treatment Effect in People with obesity (STEP) program aims to investigate the effect of semaglutide versus placebo on weight loss, safety, and tolerability in adults with obesity or overweight.

METHODS

Across five phase 3 trials (NCT03548935, WM; NCT03552757, WM in type 2 diabetes; NCT03611582, WM with intensive behavioral therapy; NCT03548987, sustained WM; and NCT03693430, long-term WM), ~5,000 participants are being randomly assigned to receive semaglutide 2.4 mg once weekly subcutaneously versus placebo. Results will be available in 2020/2021. For all trials, the primary end point is change from baseline to end of treatment in body weight.

RESULTS

Participants have a mean age of 46.2 to 55.3 years, are mostly female (mean: 74.1%-81.0%), and have a mean BMI of 35.7 to 38.5 kg/m2 and a mean waist circumference of 113.0 to 115.7 cm.

CONCLUSIONS

The STEP program evaluates the efficacy and safety of semaglutide 2.4 mg subcutaneously once weekly in a broad population. The trials will provide insights on WM in people with obesity with and without type 2 diabetes and on long-term follow-up.

Computational approaches for the discovery of natural pancreatic lipase inhibitors as antiobesity agents

Obesity is becoming one of the greatest threats to global health in the 21st century and therefore the development of novel antiobesity drugs is one of the top priorities of global drug research. An important treatment strategy includes the reduction of intestinal fat absorption through the inhibition of pancreatic lipase (PL). Natural products provide a vast pool of PL inhibitors with novel scaffolds that can possibly be developed into clinical products. Computational drug design methods have become increasingly invaluable in the drug discovery process. In recent years, the discovery of new antiobesity PL inhibitors has been facilitated by the application of computational methods. This review highlights some computer-aided drug design techniques utilized in the discovery of natural PL inhibitors.

Sarcopenic obesity in cirrhosis-The confluence of 2 prognostic titans

Sarcopenia and obesity are 2 major health conditions with a growing prevalence in cirrhosis. The concordance of these 2 conditions, sarcopenic obesity, is associated with higher rates of mortality and impact on the metabolic profile and physical function than either condition alone. To date, there is little consensus surrounding the diagnostic criteria for sarcopenia, obesity or as a result, sarcopenic obesity in patients with cirrhosis. Cross-sectional imaging, although the most accurate diagnostic technique, has practical limitations for routine use in clinical practice. Management strategies are focused on increasing muscle mass and strength. The present review provides an overview of the diagnosis, pathophysiology, prognostic implications and management strategies available for sarcopenic obesity in cirrhosis. We also discuss the associated condition myosteatosis, the pathological accumulation of fat in skeletal muscle. Much work needs to be done to advance both clinical care and research in this area. Future directions require consensus definitions for sarcopenia, obesity and sarcopenic obesity, an expansion of our understanding of the complex pathogenesis of the muscle-liver-adipose tissue axis in cirrhosis and evidence to support management recommendations for nutrition, exercise and pharmacological therapies.

d-Fenfluramine and lorcaserin inhibit the binge-like feeding induced by μ-opioid receptor stimulation of the nucleus accumbens in the rat

Multiple laboratories have shown that the stimulation of μ-opioid receptors in the nucleus accumbens (NAcc) powerfully increases intake of palatable and high-fat diets. Separate studies have demonstrated that serotonin agonists advance satiety processes, and several serotonin-targeting agents have been prescribed to promote weight loss. However, it is unknown if serotonin signaling can modulate the increased feeding elicited by activation of NAcc μ-opioid receptors. These experiments assessed the effects of systemic treatments with the serotonin agonists d-fenfluramine and lorcaserin on the binge-like feeding induced by μ-opioid receptor stimulation of the NAcc in Sprague-Dawley rats. Consistent with previous reports, stimulation of NAcc μ-opioid receptors (with 0.025 μg/0.5 μl/side DAMGO) significantly increased consumption of high-fat vegetable shortening, and systemic treatment with d-fenfluramine and lorcaserin dose-dependently decreased intake. Interestingly, d-fenfluramine and lorcaserin reversed the binge-like feeding observed following stimulation of NAcc μ-opioid receptors. Both serotonergic drugs also attenuated the increases of ambulation observed following administration of DAMGO in the NAcc. These data demonstrate that serotonergic anorectics, in addition to their known role in advancing satiety processes during normal feeding, can also inhibit the binge-like feeding that is elicited by activation of μ-opioid receptors within the ventral striatum.

Extract Enriched in Flavan-3-ols and Mainly Procyanidin Dimers Improves Metabolic Alterations in a Mouse Model of Obesity-Related Disorders Partially via Estrogen Receptor Alpha

Red wine polyphenol extracts improve cardiovascular and metabolic disorders linked to obesity. Their vascular protection is mediated by the activation of the alpha isoform of the estrogen receptor (ERα). In the present study, we explored the effects of a grape seed extract (GSE) enriched in the flavan-3-ols procyanidin dimers on obesity-related cardiovascular and metabolic disorders; with a particular interest in the role/contribution of ERα. Ovariectomized wild type or ERα knockout (KO) mice were fed with standard or western diet, supplemented or not with GSE, for 12 weeks. Their body weight was monitored throughout the study, and an echocardiography was performed at the end of the treatment. Blood and tissues were collected for biochemical and functional analysis, including nitric oxide and oxidative stress measurement. Vascular reactivity and liver mitochondrial complexes activity were also analyzed. In western diet-fed mice, GSE reduced adiposity, plasma triglycerides, and oxidative stress in the heart, liver, adipose and skeletal tissues; but did not improve the vascular dysfunction. In western diet-fed mice, ERα deletion prevented or reduced the beneficial effects of GSE on plasma triglycerides and visceral adiposity. ERα deletion also prevented/reduced the anti-oxidant effect of GSE in the liver, but did not affect its capacity to reduce oxidative stress in the heart and adipose tissue. In conclusion, dietary supplementation of GSE attenuated features of metabolic syndrome partially through ERα-dependent mechanisms. This report highlights the therapeutic potential of polyphenols, and especially extract enriched in procyanidin dimers, against the metabolic disorders associated with excessive energy intake.

Antiobesity and emetic effects of a short-length peptide YY analog and its PEGylated and alkylated derivatives

Neuropeptide Y2 receptor (Y2R) agonism is an important anorectic signal and a target of antiobesity drug discovery. Recently, we synthesized a short-length Y2R agonist, PYY-1119 (4-imidazolecarbonyl-[d-Hyp²⁴,Iva²⁵,Pya(4)²⁶,Cha^27,36,γMeLeu²⁸,Lys³⁰,Aib³¹]PYY(23-36), 1) as an antiobesity drug candidate. Compound 1 induced marked body weight loss in diet-induced obese (DIO) mice; however, 1 also induced severe vomiting in dogs at a lower dose than the minimum effective dose administered to DIO mice. The rapid absorption of 1 after subcutaneous administration caused the severe vomiting. Polyethylene glycol (PEG)- and alkyl-modified derivatives of 1 were synthesized to develop Y2R agonists with improved pharmacokinetic profiles, i.e., lower maximum plasma concentration (C_max) and longer time at maximum concentration (T_max). Compounds 5 and 10, modified with 20 kDa PEG at the N-terminus and eicosanedioic acid at the Lys³⁰ side chain of 1, respectively, showed high Y2R binding affinity and induced significant body weight reduction upon once-daily administration to DIO mice. Compounds 5 and 10, with their relatively low C_max and long T_max, partially attenuated emesis in dogs compared with 1. These results indicate that optimization of pharmacokinetic properties of Y2R agonists is an effective strategy to alleviate emesis induced by Y2R agonism.

Metformin ameliorates hepatic steatosis and improves the induction of autophagy in HFD‑induced obese mice

The present study aimed to investigate the effect of metformin on the induction of autophagy in the liver and adipose tissues of a mouse model of obesity. C57BL/6J mice were fed a high‑fat diet (HFD) for 12 weeks to induce obesity‑associated hepatic steatosis, and treated with metformin (150 mg/kg/d) by intraperitoneal injection for the final 4 weeks of HFD feeding. Body weight was recorded weekly, and the food intake of the mice was recorded daily during the treatment period. Liver and adipose tissues were harvested for histological and molecular analyses. The results revealed that metformin significantly reduced body weight without altering food intake in the HFD mice, particularly in the epididymal white adipose tissue (eWAT). Metformin treatment ameliorated HFD‑induced hepatic steatosis and serum levels of triglycerides, which was consistent with a marked increase in the expression levels of microtubule‑associated protein 1 light chain 3 (LC3) and AMP‑activated protein kinase (AMPK) in the liver following metformin treatment. However, metformin suppressed the expression of LC3 in the eWAT without altering the expression of AMPK, compared with that in the HFD mice. In conclusion, metformin reduced the body weight and hepatic steatosis of the HFD‑induced obese mice, without altering food intake. The effects of metformin treatment may be attributable to the improved induction of hepatic autophagy and the inhibited induction of adipose tissue autophagy.

The burden of obesity in the current world and the new treatments available: focus on liraglutide 3.0 mg

The prevalence of obesity increases worldwide. Treating obesity and its associated health problems has a significant economic impact on health care systems. The unsatisfactory long-term outcomes observed in the obesity treatment are due to its complex pathophysiology and the inherent difficulties associated with maintenance of lifestyle modifications. Determined by genetic and environmental factors, obesity has been officially recognized as a chronic disease, an action that allowed the recognition of anti-obesity drugs as legitimate therapeutic options to address the growing obesity endemic. Like other chronic diseases, obesity requires long-term treatment. Pharmacological interventions, when used as an adjunct to lifestyle changes, are useful to facilitate clinically meaningful weight loss, which may impact on obesity-associated comorbid conditions. In the past, medications for weight reduction were limited. However, the landscape has changed and new drugs provide additional options for weight management. Among the new drugs, liraglutide is the most studied, especially regarding its effects on the limbic system. As an adjunct to a reduced-calorie diet and increased physical activity, treatment with liraglutide 3.0 mg provides a statistically significant and clinically meaningful weight loss. Liraglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist that shares 97% homology to native GLP-1. Receptor agonists of GLP-1, including liraglutide, have emerged as effective therapies for type 2 diabetes and obesity. This review will address the major findings concerning the central regulation of appetite and the main studies that evaluated new drugs for obesity treatment, with a greater focus on liraglutide 3.0 mg.

The role of food intake regulating peptides in cardiovascular regulation

Obesity is a risk factor that worsens cardiovascular events leading to higher morbidity and mortality. However, the exact mechanisms of relation between obesity and cardiovascular events are unclear. Nevertheless, it has been demonstrated that pharmacological therapy for obesity has great potential to improve some cardiovascular problems. Therefore, it is important to determine the common mechanisms regulating both food intake and blood pressure. Several hormones produced by peripheral tissues work together with neuropeptides involved in the regulation of both food intake and blood pressure. Anorexigenic (food intake lowering) hormones such as leptin, glucagon-like peptide-1 and cholecystokinin cooperate with α-melanocyte-stimulating hormone, cocaine- and amphetamine-regulated peptide as well as prolactin-releasing peptide. Curiously their collective actions result in increased sympathetic activity, especially in the kidney, which could be one of the factors responsible for the blood pressure increases seen in obesity. On the other hand, orexigenic (food intake enhancing) peptides, especially ghrelin released from the stomach and acting in the brain, cooperates with orexins, neuropeptide Y, melanin-concentrating hormone and galanin, which leads to decreased sympathetic activity and blood pressure. This paradox should be intensively studied in the future. Moreover, it is important to know that the hypothalamus together with the brainstem seem to be major structures in the regulation of food intake and blood pressure. Thus, the above mentioned regions might be essential brain components in the transmission of peripheral signals to the central effects. In this short review, we summarize the current information on cardiovascular effects of food intake regulating peptides.

Through Thick and Thin: Identifying Barriers to Bariatric Surgery, Weight Loss Maintenance, and Tailoring Obesity Treatment for the Future

More than one-third of the adults in the United States are obese. This complex metabolic disorder is associated with multiple comorbidities and increased all-cause mortality. Bariatric surgery has been shown to be more effective than medical therapy and has been associated with weight loss maintenance and decreased mortality. In spite of these well-established benefits, less than 1% of candidates undergo surgery due to multiple factors, such as patient and physician perceptions and attitudes, patient-physician interaction, lack of resources, and cost burden. Furthermore, even in patients who do undergo bariatric surgery and/or alternate weight loss interventions, long-term weight control is associated with high-risk failure and weight regain. In this review, we highlight some of the current barriers to bariatric surgery and long-term weight loss maintenance and underscore the importance of an individualized multidisciplinary longitudinal strategy for the treatment of obesity.