Obesity medications in development

Sipyimigwanjung-tang, a traditional herbal medication, alleviates weight gain in a high-fat diet-induced obese mice model

Obesity leads to the development of metabolic syndrome and comorbidities. Overweight and obesity continue to be a relentless global issue. Sipyimigwanjung-tang (SGT), a traditional herbal medication, was first mentioned in Dongui Sasang Shinpyun and has been used to treat edema, meteorism, and jaundice, which are common findings associated with obesity. The main physiological feature of obesity is expanded adipose tissue, which causes several impairments in liver metabolism. Therefore, this study aimed to investigate the anti-obesity effects of SGT in the epididymal white adipose tissue (eWAT) and livers of high-fat diet (HFD)-induced obese mice. SGT significantly blocked HFD-induced weight gain in C57BL/6N mice. In addition, SGT effectively reduced the increased weight and adipocyte size in eWAT of HFD-induced obese C57BL/6 N mice. Moreover, SGT significantly decreased the elevated gene expression of Peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, and Sterol regulatory element-binding protein 1 in the eWAT of HFD-induced obese mice. Furthermore, SGT significantly decreased lipid accumulation in the livers of HFD-induced obese mice and differentiated 3T3-L1 adipocytes. Hence, the present study provides substantial evidence that SGT has potential therapeutic effects on obesity.

Differential Interventional Effects of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on High Fat Diet-Induced Obesity and Hepatic Pathology

Current Dietary Guidelines for Americans recommend replacing saturated fat (SFA) intake with polyunsaturated fatty acids (PUFAs) and monosaturated fatty acids (MUFAs) but do not specify the type of PUFAs, which consist of two functionally distinct classes: omega-6 (n-6) and omega-3 (n-3) PUFAs. Given that modern Western diets are already rich in n-6 PUFAs and the risk of chronic disease remains high today, we hypothesized that increased intake of n-3 PUFAs, rather than n-6 PUFAs, would be a beneficial intervention against obesity and related liver diseases caused by high-fat diets. To test this hypothesis, we fed C57BL/6J mice with a high-fat diet (HF) for 10 weeks to induce obesity, then divided the obese mice into three groups and continued feeding for another 10 weeks with one of the following three diets: HF, HF+n-6 (substituted half of SFA with n-6 PUFAs), and HF+n-3 (substituted half of SFA with n-3 PUFAs), followed by assessment of body weight, fat mass, insulin sensitivity, hepatic pathology, and lipogenesis. Interestingly, we found that the HF+n-6 group, like the HF group, had a continuous increase in body weight and fat mass, while the HF+n-3 group had a significant decrease in body weight and fat mass, although all groups had the same calorie intake. Accordingly, insulin resistance and fatty liver pathology (steatosis and fat levels) were evident in the HF+n-6 and HF groups but barely seen in the HF+n-3 group. Furthermore, the expression of lipogenesis-related genes in the liver was upregulated in the HF+n-6 group but downregulated in the HF+n-3 group. Our findings demonstrate that n-6 PUFAs and n-3 PUFAs have differential effects on obesity and fatty liver disease and highlight the importance of increasing n-3 PUFAs and reducing n-6 PUFAs (balancing the n-6/n-3 ratio) in clinical interventions and dietary guidelines for the management of obesity and related diseases.

360-Degree Perspectives on Obesity

Alarming statistics show that the number of people affected by excessive weight has surpassed 2 billion, representing approximately 30% of the world's population. The aim of this review is to provide a comprehensive overview of one of the most serious public health problems, considering that obesity requires an integrative approach that takes into account its complex etiology, including genetic, environmental, and lifestyle factors. Only an understanding of the connections between the many contributors to obesity and the synergy between treatment interventions can ensure satisfactory outcomes in reducing obesity. Mechanisms such as oxidative stress, chronic inflammation, and dysbiosis play a crucial role in the pathogenesis of obesity and its associated complications. Compounding factors such as the deleterious effects of stress, the novel challenge posed by the obesogenic digital (food) environment, and the stigma associated with obesity should not be overlooked. Preclinical research in animal models has been instrumental in elucidating these mechanisms, and translation into clinical practice has provided promising therapeutic options, including epigenetic approaches, pharmacotherapy, and bariatric surgery. However, more studies are necessary to discover new compounds that target key metabolic pathways, innovative ways to deliver the drugs, the optimal combinations of lifestyle interventions with allopathic treatments, and, last but not least, emerging biological markers for effective monitoring. With each passing day, the obesity crisis tightens its grip, threatening not only individual lives but also burdening healthcare systems and societies at large. It is high time we took action as we confront the urgent imperative to address this escalating global health challenge head-on.

Dietary cysteine drives body fat loss via FMRFamide signaling in Drosophila and mouse

Obesity imposes a global health threat and calls for safe and effective therapeutic options. Here, we found that protein-rich diet significantly reduced body fat storage in fruit flies, which was largely attributed to dietary cysteine intake. Mechanistically, dietary cysteine increased the production of a neuropeptide FMRFamide (FMRFa). Enhanced FMRFa activity simultaneously promoted energy expenditure and suppressed food intake through its cognate receptor (FMRFaR), both contributing to the fat loss effect. In the fat body, FMRFa signaling promoted lipolysis by increasing PKA and lipase activity. In sweet-sensing gustatory neurons, FMRFa signaling suppressed appetitive perception and hence food intake. We also demonstrated that dietary cysteine worked in a similar way in mice via neuropeptide FF (NPFF) signaling, a mammalian RFamide peptide. In addition, dietary cysteine or FMRFa/NPFF administration provided protective effect against metabolic stress in flies and mice without behavioral abnormalities. Therefore, our study reveals a novel target for the development of safe and effective therapies against obesity and related metabolic diseases.

Phase I studies of the safety, tolerability, pharmacokinetics and pharmacodynamics of the dual glucagon receptor/glucagon-like peptide-1 receptor agonist BI 456906

AIM

To report two phase I studies of the novel subcutaneous glucagon-like peptide-1 receptor/glucagon receptor (GLP-1R/GCGR) dual agonist BI 456906 versus placebo in healthy volunteers and people with overweight/obesity.

MATERIALS AND METHODS

A phase Ia study (NCT03175211) investigated single rising doses (SRDs) of BI 456906 in 24 males with a body mass index (BMI) of 20-<30 kg/m² . A phase Ib study (NCT03591718) investigated multiple rising doses (MRDs) of BI 456906 (escalated over 6 [Part A] or 16 [Part B] weeks) in 125 adults with a BMI of 27-40 kg/m² .

RESULTS

In the SRD study (N = 24), mean body weight decreased with increasing BI 456906 dose. In the MRD study, the maximum decreases in placebo-corrected mean body weight were at week 6 (-5.79%, dosage schedule [DS] 1; Part A) and week 16 (-13.8%, DS7; Part B). BI 456906 reduced plasma amino acids and glucagon, indicating target engagement at GCGRs and GLP-1Rs. Drug-related adverse events (AEs) increased with BI 456906 dose. The most frequent drug-related AE with SRDs was decreased appetite (n = 9, 50.0%), and two subjects (8.3%) did not complete the trial because of AEs (nausea and vomiting). During MRD Part A (N = 80), 10 subjects (12.5%) discontinued BI 456906, most commonly because of a cardiac or vascular AE (n = 6, 7.5%); during Part B (N = 45), eight subjects (17.8%) discontinued BI 456906, mainly because of AEs (n = 6, 13.3%), most commonly gastrointestinal disorders.

CONCLUSIONS

BI 456906 produced a placebo-corrected body weight loss of 13.8% (week 16), highlighting its potential to promote clinically meaningful body weight loss in people with overweight/obesity.

Estimated minimum prices and lowest available national prices for antiobesity medications: Improving affordability and access to treatment

OBJECTIVE

Novel antiobesity treatments are highly effective in recent clinical trials. Access to these medications is needed to supplement lifestyle and surgical interventions for millions living with obesity worldwide, but high prices are limiting. This study aimed to review current treatment costs and calculate potential estimated minimum prices (EMPs).

METHODS

The authors searched national drug price databases across various countries for orlistat, naltrexone-bupropion, topiramate-phentermine, liraglutide, semaglutide, and tirzepatide. EMPs for antiobesity medications were calculated using established methodology, using active pharmaceutical ingredients (API) from the Panjiva database. EMPs were calculated per 30-day course and include costs of active pharmaceutical ingredients, excipients, formulation, taxation, and 10% profit margin.

RESULTS

National prices of antiobesity medications were significantly higher than calculated EMPs. Semaglutide 30-day course prices ranged from $804 (United States) to $95 (Turkey) while the EMP was $40. Liraglutide prices ranged from $1418 (United States) to $252 (Norway) while the EMP was $50. Some oral treatments could be generically manufactured at very low costs per course ($7 for orlistat; $5 for phentermine/topiramate combination tablets), while naltrexone/bupropion was more expensive ($54).

CONCLUSIONS

This study shows that certain weight loss treatments can be manufactured and sold profitably at low costs, but prices currently range widely between countries, limiting access for those in need.

Chemical constituents from the seeds of Cullen corylifolium and their inhibitory activity on diacylglycerol acyltransferase

A large number of extracts of medicinal plants or natural products shows beneficial to combat obesity. In the present work, a new flavonoid named (2S,1″R,2″R)-4'-hydroxy-7-methoxy-6-(1,2,3-trihydroxy-3-methyl-butyl)-flavanone (1), along with seven known compounds (2-8) were isolated from the seeds of Cullen corylifolium. Their structures, including the absolute configurations, were determined by the analysis of comprehensive spectroscopic data and computational calculation methods. All isolates were evaluated for their diacylglycerol acyltransferase (DGAT) inhibitory activity. Compounds 1-4 exhibited different level of DGAT1 inhibitory activity with IC₅₀ values ranging from 28.2 ± 1.1 to 127.3 ± 1.9 μM. In addition, 45 flavonoids which be evaluated for DGAT inhibitory activity were summarised and potential structure-activity relationships were discussed.

Brexpiprazole Reduces 5-HT7 Receptor Function on Astroglial Transmission Systems

Several atypical antipsychotics exert mood-stabilising effects via the modulation of various monoamine receptors and intracellular signallings. Recent pharmacodynamic studies suggested that tripartite synaptic transmission can contribute to the pathophysiology of schizophrenia and mood disorders, their associated cognitive impairment, and several adverse reactions to atypical antipsychotics. Therefore, to explore the mechanisms underlying the antidepressive mood-stabilising and antipsychotic effects of brexpiprazole (Brex), we determined the effects of subchronic administration of therapeutically relevant concentrations/doses of Brex on the protein expression of 5-HT receptors, connexin43, cAMP levels, and intracellular signalling in cultured astrocytes and rat hypothalamus using ultra-high-pressure liquid chromatography with mass spectrometry and capillary immunoblotting systems. Subchronic administration of a therapeutically relevant concentration of Brex (300 nM) downregulated both 5-HT1A (5-HT1AR) and 5-HT7 (5-HT7R) receptors, in addition to phosphorylated Erk (pErk), without affecting phosphorylated Akt in the astroglial plasma membrane. Subchronic administration of 300 nM Brex decreased and increased phosphorylated AMPK and connexin43, respectively, in the astroglial cytosol fraction. A therapeutically relevant concentration of Brex acutely decreased the astroglial cAMP level, whereas, under the inhibition of 5-HT1AR, Brex did not affect astroglial cAMP levels. However, the 5-HT7R-agonist-induced increased astroglial cAMP level was inhibited by Brex. In contrast to the in vitro study, systemic subchronic administration of effective doses of Brex (3 and 10 mg/kg/day for 14 days) increased the cAMP level but did not affect phosphorylated AMPK in the rat hypothalamus. These results suggest several complicated pharmacological features of Brex. Partial 5-HT1AR agonistic action predominates in the low range of therapeutically relevant concentrations of Brex, whereas in the high range, 5-HT7R inverse agonist-like action is overlapped on the 5-HT1A agonistic action. These unique suppressive effects of Brex on 5-HT7R play important roles in the clinical features of Brex regarding its antidepressive mood-stabilising actions.

Metabolic Profiling of Mice with Deletion of the Orphan G Protein-Coupled Receptor, GPR37L1

Understanding the neurogenic causes of obesity may reveal novel drug targets to counter the obesity crisis and associated sequelae. Here, we investigate whether the deletion of GPR37L1, an astrocyte-specific orphan G protein-coupled receptor, affects whole-body energy homeostasis in mice. We subjected male Gpr37l1−/− mice and littermate wildtype (Gpr37l1+/+, C57BL/6J background) controls to either 12 weeks of high-fat diet (HFD) or chow feeding, or to 1 year of chow diet, with body composition quantified by EchoMRI, glucose handling by glucose tolerance test and metabolic rate by indirect calorimetry. Following an HFD, Gpr37l1−/− mice had similar glucose handling, body weight and fat mass compared with wildtype controls. Interestingly, we observed a significantly elevated respiratory exchange ratio in HFD- and chow-fed Gpr37l1−/− mice during daylight hours. After 1 year of chow feeding, we again saw no differences in glucose and insulin tolerance or body weight between genotypes, nor in energy expenditure or respiratory exchange ratio. However, there was significantly lower fat mass accumulation, and higher ambulatory activity in the Gpr37l1−/− mice during night hours. Overall, these results indicate that while GPR37L1 may play a minor role in whole-body metabolism, it is not a viable clinical target for the treatment of obesity.

Tuina combined with diet and exercise for simple obesity: A protocol for systematic review

BACKGROUND

The incidence of simple obesity is increasing annually, with the number of obese people in all age groups increasing significantly. Obesity has become an important public health concern. Simple obesity affects not only appearance but also health. Obesity has an increasing impact on individuals, families, and society. Therefore, the treatment of obesity is becoming increasingly important. Prior studies have shown that Tuina combined with diet and exercise is capable of producing improvements in body weight and fasted health markers. In recent years, there are many clinical studies on the intervention of simple obesity by Tuina combined with diet and exercise, however, no study systematically evaluated the clinical efficacy. The purpose of this study is to evaluate its effects of Tuina combined with diet and exercise on people with simple obesity.

METHODS

We will search the following electronic databases: PubMed, EMBASE, MEDLINE, Web of science, Cochrane Library, WanFang Data, CBM, CNKI, and VIP from the inception of the coverage of these databases to December 2021. Randomized controlled clinical trials related to Tuina combined with diet and exercise intervention on simple obesity will be included. Cochrane's collaboration tool will be used to assess the quality of the studies. RevMan 5.3 software will be used for the data analysis.

RESULTS

This study will provide a standardized evaluation for the efficacy of Tuina combined with diet and exercise for simple obesity.

CONCLUSION

The conclusion of this study will provide evidence for the safety and effectiveness of Tuina combined with diet and exercise on weight loss.

ETHICS AND DISSEMINATION

Ethical approval is not required for systematic review and meta- analysis. The results of this review will be disseminated in a peer-review journal.

PROSPERO REGISTRATION NUMBER

INPLASY202210079.

Diet Impact on Obesity beyond Calories and Trefoil Factor Family 2 (TFF2) as an Illustration: Metabolic Implications and Potential Applications

Obesity is a health problem with increasing impacts on public health, economy and even social life. In order to reestablish the energy balance, obesity management focuses mainly on two pillars; exercise and diet. Beyond the contribution to the caloric intake, the diet nutrients and composition govern a variety of properties. This includes the energy balance-independent properties and the indirect metabolic effects. Whereas the energy balance-independent properties are close to "pharmacological" effects and include effects such as antioxidant and anti-inflammatory, the indirect metabolic effects represent the contribution a diet can have on energy metabolism beyond the caloric contribution itself, which include the food intake control and metabolic changes. As an illustration, we also described the metabolic implication and hypothetical pathways of the high-fat diet-induced gene Trefoil Factor Family 2. The properties the diet has can have a variety of applications mainly in pharmacology and nutrition and further explore the "pharmacologically" active food towards potential therapeutic applications.

Drugs for Treating Obesity

Older medications approved for chronic weight management (orlistat, naltrexone/bupropion, liraglutide 3 mg and, in the USA, phentermine/topiramate) have not been widely adopted by health care providers. Those medications produce only modest additional weight loss when used to augment lifestyle intervention. However, semaglutide 2.4 mg weekly has recently emerged and produces much more weight loss - on average 15% weight loss at 1 year. Semaglutide's enhanced efficacy and that its class (GLP-1 receptor analogs) is well-known may result in more clinicians adopting pharmacotherapy. Furthermore, the first dedicated cardiovascular outcome trial powered for superiority testing an anti-obesity medication (SELECT) is underway with semaglutide 2.4 mg. A positive outcome will further promote the concept that weight management should be a primary target for cardiometabolic disease control. In phase 3, tirzepatide and cagrilintide/semaglutide combination are showing promise for even greater weight loss efficacy. Another recently approved medication takes a personalized medicine approach; setmelanotide is approved as a therapy for those with some of the ultra-rare genetic diseases characterized by severe, early onset obesity. This chapter reviews the currently available and anticipated medications for chronic weight management as well as those approved for the genetic and syndromic obesities.

Next Generation Antiobesity Medications: Setmelanotide, Semaglutide, Tirzepatide and Bimagrumab: What do They Mean for Clinical Practice?

There is a new generation of antiobesity drugs in development or just arriving on the scene. First, setmelanotide has been approved for three of the ultrarare genetic conditions that cause obesity–pro-opiomelanocortin deficiency, proprotein convertase subtilisin and kexin type 1 (an important enzyme in the melanocortin pathway) and leptin receptor deficiency. Setmelanotide marks the first in a personalized medicine approach to obesity. Second, semaglutide 2.4 mg once weekly has been submitted to regulators in the United States and the European Union for approval for patients with obesity (body mass index [BMI] ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) and at least one weight related comorbidity. This drug has been studied in five phase 3 clinical trials, four discussed herein: semaglutide produces roughly twice as much weight loss as we have seen in older antiobesity medications. Semaglutide is already in use for treatment of diabetes and, as a glucagon-like peptide 1 (GLP-1) receptor analog, is part of a class of drugs used widely in diabetes. Tirzepatide, a glucose-insulin peptide and GLP-1 dual agonist is in phase 3 study for obesity management, and bimagrumab is a new agent in phase 2 with a unique mechanism of action; they are generating much interest. The purpose of this narrative review is lay the groundwork for a discussion of the clinical impact of these new medications on the clinical practice of obesity. Further, these developments shall be used to launch a speculation of what is likely to be their impact on the future of obesity pharmacotherapy.

Effects of Bacillus Subtilis-Fermented White Sword Bean Extract on Adipogenesis and Lipolysis of 3T3-L1 Adipocytes

To investigate the adipogenesis and lipolysis effects of the Bacillus subtilis-fermented white sword bean extract (FWSBE) on 3T3-L1 adipocytes, we treated 3T3-L1 preadipocytes before and after differentiation with FWSBE and measured triglyceride, free glycerol, mRNA, and protein levels. First, FWSBE reduced the cell viability of 3T3-L1 pre-adipocytes under 1000 µg/mL conditions. Triglyceride accumulation in 3T3-L1 pre-adipocytes was suppressed, and free glycerol content in mature 3T3-L1 adipocytes was increased in the FWSBE treatment groups, indicating that FWSBE has anti-obesity effects. Further, FWSBE suppressed adipogenesis in 3T3-L1 pre-adipocytes by lowering the protein levels of C/EBPα, PPARγ, and FAS and increasing the level of pACC and pAMPK. Additionally, FWSBE promoted lipolysis in mature 3T3-L1 adipocytes by increasing the transcription levels of Ppara, Acox, and Lcad and the protein levels of pHSL and ATGL. Thus, we suggest that FWSBE can be a potential dietary supplement because of its anti-obesity properties.

Obese Animals as Models for Numerous Diseases: Advantages and Applications

With the advances in obesity research, a variety of animal models have been developed to investigate obesity pathogenesis, development, therapies and complications. Such obese animals would not only allow us to explore obesity but would also represent models to study diseases and conditions that develop with obesity or where obesity represents a risk factor. Indeed, obese subjects, as well as animal models of obesity, develop pathologies such as cardiovascular diseases, diabetes, inflammation and metabolic disorders. Therefore, obese animals would represent models for numerous diseases. Although those diseases can be induced in animals by chemicals or drugs without obesity development, having them developed as consequences of obesity has numerous advantages. These advantages include mimicking natural pathogenesis processes, using diversity in obesity models (diet, animal species) to study the related variabilities and exploring disease intensity and reversibility depending on obesity development and treatments. Importantly, therapeutic implications and pharmacological tests represent key advantages too. On the other hand, obesity prevalence is continuously increasing, and, therefore, the likelihood of having a patient suffering simultaneously from obesity and a particular disease is increasing. Thus, studying diverse diseases in obese animals (either induced naturally or developed) would allow researchers to build a library of data related to the patterns or specificities of obese patients within the context of pathologies. This may lead to a new branch of medicine specifically dedicated to the diseases and care of obese patients, similar to geriatric medicine, which focuses on the elderly population.

Obesity: Epidemiology, Pathophysiology, and Therapeutics

Obesity is a complex multifactorial disease that accumulated excess body fat leads to negative effects on health. Obesity continues to accelerate resulting in an unprecedented epidemic that shows no significant signs of slowing down any time soon. Raised body mass index (BMI) is a risk factor for noncommunicable diseases such as diabetes, cardiovascular diseases, and musculoskeletal disorders, resulting in dramatic decrease of life quality and expectancy. The main cause of obesity is long-term energy imbalance between consumed calories and expended calories. Here, we explore the biological mechanisms of obesity with the aim of providing actionable treatment strategies to achieve a healthy body weight from nature to nurture. This review summarizes the global trends in obesity with a special focus on the pathogenesis of obesity from genetic factors to epigenetic factors, from social environmental factors to microenvironment factors. Against this background, we discuss several possible intervention strategies to minimize BMI.

Research and prospect of peptides for use in obesity treatment (Review)

Obesity and its related diseases, such as type 2 diabetes, hypertension and cardiovascular disease, are steadily increasing worldwide. Over the past few decades, numerous studies have focused on the differentiation and function of brown and beige fat, providing evidence for their therapeutic potential in treating obesity. However, no specific novel drug has been developed to treat obesity in this way. Peptides are a class of chemically active substances, which are linked together by amino acids using peptide bonds. They have specific physiological activities, including browning of white fat. As signal molecules regulated by the neuroendocrine system, the role of polypeptides, such as neuropeptide Y, brain-gut peptide and glucagon-like peptide in obesity and its related complications has been revealed. Notably, with the rapid development of peptidomics, peptide drugs have been widely used in the prevention and treatment of metabolic diseases, due to their short half-life, small apparent distribution volume, low toxicity and low side effects. The present review summarizes the progress and the new trend of peptide research, which may provide novel targets for the prevention and treatment of obesity.

Appetite control: hormones or diet strategies?

PURPOSE OF REVIEW

Appetite control results from metabolic, behavioral, and environmental factors that influence hunger and the desire to eat. We summarize the latest advances in the hormonal and nutritional strategies to control appetite and reduce hunger.

RECENT FINDINGS

The fed-hunger-state is regulated by central and peripheric hormones, which modulate energy balance. Leptin, insulin, ghrelin, peptide YY (PYY), and other gut-derived peptides represent the main appetite controllers. The role of orexins, obestatin, and liver-expressed antimicrobial peptide 2 has been uncovered recently. New insights have demonstrated the role of hippocampal activity as a possible mechanism of action. Glucagon-like peptide 1 (GLP1) receptor agonists are well known agents controlling appetite. Association of GLP1 receptor agonist, PYY, or glucose-dependent insulinotropic polypeptide agonists have been tested as new approaches. Appetite-control hormones have also risen as factors involved in the efficacy of bariatric procedures. High-protein, ketogenic diet, and intermittent fasting have been described as nutritional strategies to reduce appetite, although the physiological mechanism and long-term safety remains unclear.

SUMMARY

Appetite control has been an important target for the treatment of obesity and associated disorders. New studies have demonstrated promising adoption of dietary approaches, hormone-based drugs, and bariatric surgery to control energy intake. Further research will establish a significant association, benefits, and safety of these new therapies.

Exploring Therapeutic Targets to Reverse or Prevent the Transition from Metabolically Healthy to Unhealthy Obesity

The prevalence of obesity and obesity-related metabolic comorbidities are rapidly increasing worldwide, placing a huge economic burden on health systems. Excessive nutrient supply combined with reduced physical exercise results in positive energy balance that promotes adipose tissue expansion. However, the metabolic response and pattern of fat accumulation is variable, depending on the individual’s genetic and acquired susceptibility factors. Some develop metabolically healthy obesity (MHO) and are resistant to obesity-associated metabolic diseases for some time, whereas others readily develop metabolically unhealthy obesity (MUO). An unhealthy response to excess fat accumulation could be due to susceptibility intrinsic factors (e.g., increased likelihood of dedifferentiation and/or inflammation), or by pathogenic drivers extrinsic to the adipose tissue (e.g., hyperinsulinemia), or a combination of both. This review outlines the major transcriptional factors and genes associated with adipogenesis and regulation of adipose tissue homeostasis and describes which of these are disrupted in MUO compared to MHO individuals. It also examines the potential role of pathogenic insulin hypersecretion as an extrinsic factor capable of driving the changes in adipose tissue which cause transition from MHO to MUO. On this basis, therapeutic approaches currently available and emerging to prevent and reverse the transition from MHO to MUO transition are reviewed.

Chitosan oligosaccharide ameliorated obesity by reducing endoplasmic reticulum stress in diet-induced obese rats

OBJECTIVE

This study aimed to determine whether chitosan oligosaccharide (COST) improves overweight by reducing endoplasmic reticulum (ER) stress in the liver and liver cancer cells.

METHODS

An obesity model was established by feeding Sprague-Dawley rats (ORs) a high-fat diet (HFD) and treating them with COST for 8 weeks. A model of lipid accumulation in hepatocellular carcinoma cells was established by treating HepG2 cells with free fatty acids and COST for 24 h.

RESULTS

COST treatment of ORs reduced weight gain, inhibited adipose tissue hypertrophy and hyperplasia, and reduced the fat-to-weight ratio. COST improved dyslipidaemia, reduced liver weight and organ index, inhibited hepatic lipid accumulation, and prevented liver steatosis, and the high COST dose increased TC and TG excretion in the stool. Treatment of lipid accumulation in HepG2 cells with COST reduced lipid accumulation and TG levels. COST modulated the expression of genes related to fat metabolism and ER stress response pathway-related factors in liver tissue and HepG2 cells.

CONCLUSIONS

COST can inhibit weight gain and improve dyslipidaemia and lipid metabolism in ORs. The COST-mediated regulation of hepatic and HepG2 cell lipid metabolism might be related to inhibition of fat synthesis, acceleration of lipid oxidative catabolism and reduction in ER stress.

GDF-15 as a Weight Watcher for Diabetic and Non-Diabetic People Treated With Metformin

Weight gain and obesity are global health concerns contributing to morbidity with increased risks of cardiovascular disease, diabetes, liver steatohepatitis and cancer. Pharmacological therapies or bariatric surgery are often required for those who fail to adhere to diet and lifestyle modifications. Metformin, a widely used antidiabetic agent, seems to have a health benefit beyond its anti-hyperglycemic properties, with few side effects. Emerging evidence shows weight loss to be associated with metformin in both diabetic and non-diabetic individuals. Recently, the growth differentiation factor 15 (GDF-15), a member of the transforming growth factor beta superfamily, has been identified as a key mediator of metformin-induced weight loss. Metformin increases the secretion of GDF-15, which binds exclusively to glial cell-derived neurotrophic factor family receptor alpha-like (GFRAL). This gut-brain cytokine works as a prominent player in reducing food intake and body weight in health and disease, like anorexia nervosa and cancer. Herein, we critically review advances in the understanding of the weight-reducing effects of metformin via the GDF-15 pathway.