The obesity pipeline: current strategies in the development of anti-obesity drugs

Adjuvant and Neo-Adjuvant Anti-Obesity Medications and Bariatric Surgery: A Scoping Review

PURPOSE OF REVIEW

To comprehensively summarize the current body of literature on the topic of adjuvant and neoadjuvant pharmacotherapy used in combination with bariatric surgery.

RECENT FINDINGS

Anti-obesity medications (AOMs) have been used since the mid-1900s; however, their use in combination with bariatric surgery is a newer area of research that is rapidly growing. Pharmacotherapy may be used before (neoadjuvant) or after (adjuvant) bariatric surgery. Recent literature suggests that adjuvant AOMs may address weight regain and inadequate weight loss following bariatric surgery. Research on neoadjuvant AOM used to optimize weight loss before bariatric surgery is more limited. A literature review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Thirty-four studies were included after screening and exclusion of irrelevant records. Included studies were as follows: seven prospective studies on adjuvant AOM use, 23 retrospective studies on adjuvant AOM use, one prospective study on adjuvant and neoadjuvant AOM use, one retrospective study on adjuvant or neoadjuvant AOM use, one prospective study on neoadjuvant AOM use, and one case series on neoadjuvant AOM use. In the following scoping review, each of these studies is discussed with the goal of presenting a complete synthesis of the current body of literature on AOM use in combination with bariatric surgery.

Illuminating the neuropeptide Y4 receptor and its ligand pancreatic polypeptide from a structural, functional, and therapeutic perspective

The neuropeptide Y4 receptor (Y4R), a rhodopsin-like G protein-coupled receptor (GPCR) and the hormone pancreatic polypeptide (PP) are members of the neuropeptide Y family consisting of four receptors (Y1R, Y2R, Y4R, Y5R) and three highly homologous peptide ligands (neuropeptide Y, peptide YY, PP). In this family, the Y4R is of particular interest as it is the only subtype with high affinity to PP over NPY. The Y4R, as a mediator of PP signaling, has a pivotal role in appetite regulation and energy homeostasis, offering potential avenues for the treatment of metabolic disorders such as obesity. PP as anorexigenic peptide is released postprandial from the pancreas in response to food intake, induces satiety signals and contributes to hamper excessive food intake. Moreover, this system was also described to be associated with different types of cancer: overexpression of Y4R have been found in human adenocarcinoma cells, while elevated levels of PP are related to the development of pancreatic endocrine tumors. The pharmacological relevance of the Y4R advanced the search for potent and selective ligands for this receptor subtype, which will be significantly progressed through the elucidation of the active state PP-Y4R cryo-EM structure. This review summarizes the development of novel PP-derived ligands, like Obinepitide as dual Y2R/Y4R agonist in clinical trials or UR-AK86c as small hexapeptide agonist with picomolar affinity, as well as the first allosteric modulators that selectively target the Y4R, e.g. VU0506013 as potent Y4R positive allosteric modulator or (S)-VU0637120 as allosteric antagonist. Here, we provide valuable insights into the complex physiological functions of the Y4R and PP and the pharmacological relevance of the system in appetite regulation to open up new avenues for the development of tool compounds for targeted therapies with potential applications in metabolic disorders.

Anti-Obesity Drug Delivery Systems: Recent Progress and Challenges

Obesity has reached an epidemic proportion in the last thirty years, and it is recognized as a major health issue in modern society now with the possibility of serious social and economic consequences. By the year 2030, nearly 60% of the global population may be obese or overweight, which emphasizes a need for novel obesity treatments. Various traditional approaches, such as pharmacotherapy and bariatric surgery, have been utilized in clinical settings to treat obesity. However, these methods frequently show the possibility of side effects while remaining ineffective. There is, therefore, an urgent need for alternative obesity treatments with improved efficacy and specificity. Polymeric materials and chemical strategies are employed in emerging drug delivery systems (DDSs) to enhance therapy effectiveness and specificity by stabilizing and controlling the release of active molecules such as natural ingredients. Designing DDSs is currently a top priority research objective with an eye towards creating obesity treatment approaches. In reality, the most recent trends in the literature demonstrate that there are not enough in-depth reviews that emphasize the current knowledge based on the creation and design of DDSs for obesity treatment. It is also observed in the existing literature that a complex interplay of different physical and chemical parameters must be considered carefully to determine the effectiveness of the DDSs, including microneedles, for obesity treatment. Additionally, it is observed that these properties depend on how the DDS is synthesized. Although many studies are at the animal-study stage, the use of more advanced DDS techniques would significantly enhance the development of safe and efficient treatment approaches for obese people in the future. Considering these, this review provides an overview of the current anti-obesity treatment approaches as well as the conventional anti-obesity therapeutics. The article aims to conduct an in-depth discussion on the current trends in obesity treatment approaches. Filling in this knowledge gap will lead to a greater understanding of the safest ways to manage obesity.

Non-Cardiotoxic Tetradecanoic Acid-2,4-Dinitrophenol Ester Nanomicelles in Microneedles Exert Potent Anti-Obesity Effect by Regulating Adipocyte Browning and Lipogenesis

Sustained oral uncoupler 2,4-dinitrophenol (DNP) administration exerts prominent anti-obesity effects, but the adipose tissue off-target disadvantage leads to systemic adverse effects. A novel non-cardiotoxicity DNP delivery method using a biocompatible microneedles patch containing the amphiphilic tetradecanoic acid-DNP ester (TADNP) is described, which is synthesized via esterification on the phenolic hydroxyl of DNP. The TADNP is self-assembled as nanomicelles, which enhance the endocytosis rate of DNP by adipocytes and its permeation in isolated adipose tissues. The microenvironment of adipose tissues promotes the massive release of DNP and plasma and simulated gastrointestinal fluids. The microneedles-delivered TADNP nanomicelles (MN-TADNP) effectively deliver DNP in treated adipose tissues and reduce DNP content in off-target organs. Both oral and MN patch-delivered TADNP micelles effectively exert anti-obesity effects in a mouse model of high-fat diet-induced obesity; and noteworthily, MN-TADNP exhibit more satisfactory biosafety than oral administration. Here, a smart MN patch loaded with tetradecanoic acid-modified DNP is reported, which enhances its accumulation in adipose tissues and exerts an anti-obesity effect without causing any systemic toxicity.

In Vitro α-Amylase, α-Glucosidase, Pancreatic Lipase, Xanthine Oxidase Inhibiting Activity of Agaricus bisporus Extracts

In this study, the α-amylase inhibitory activity, α-glucosidase inhibitory activity, pancreatic lipase inhibitory activity, and Xanthine Oxidase inhibitory activity of the fruiting body extracts of 5 varieties of Agaricus bisporus (AB) were confirmed. First, the α-amylase inhibitory activity of AB12, AB13, AB18, AB34, and AB40 methanol extracts was lower than that of acarbose, a positive control, in all concentration ranges. The α-glucosidase inhibitory activity of the AB40, AB13, and AB12 methanol extracts at the extract concentration of 1.0 mg/mL was 80.5%, 81.3%, and 78.5%, respectively, similar to that of acarbose, a positive control. The pancreatic lipase inhibitory activity of the methanol extract of Agaricus bisporus fruiting body was significantly lower than that of the positive control orlistat in the concentration range of 50 ∼ 1.000 (mg/mL). The Xanthine Oxidase inhibitory activity was 0.5 ∼ 8.0 mg/mL of each extract, which was significantly lower than that of the positive control allopurinol in the same concentration range. However, the Xanthine Oxidase inhibitory activity of AB13 and AB40 at 8.0 mg/mL was about 70%, which was higher than that of other mushrooms. In conclusion, five kinds of Agaricus bisporus fruiting bodies seem to have inhibitory effects on enzymes such as α-amylase, α-glucosidase, pancreatic lipase, and Xanthine Oxidase that degrade starch and protein. In particular, it has an inhibitory effect and a reduction effect on xanthine oxidase that causes gout, so it is expected that it can be developed and used as a food or health supplement with health functional properties through future research.

Effects of the Antiobesity Drugs Aplex and Venera on Certain Biochemical and Physiological Indices in Obese Adult Male Albino Rats

Background

Because of the growing incidence of obesity, the use of synthetic antiobesity medicines as weight-loss agents has grown in popularity, although their usefulness has yet to be established. Two of such medicines are Aplex and Venera. This study is designed to determine the potential dangers of Aplex and Venera on certain biochemical and physiological indicators in obese adult male rats.

Methods

Twenty-one obese male albino rats (9 weeks old and having a body mass of 220 ± 20 g) were divided into three equal groups: the control group (vehicle treatment), the Aplex group (0.1 mg/kg/day) for 30 days, and the Venera group (0.1 mg/kg/day) for 30 days.

Results

The values of serum glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR), total protein, total cholesterol (TC), high-density lipoprotein (HDL), very-low-density lipoprotein (VLDL), TC/HDL ratio, testosterone, thyroxine (T4), and leptin did not differ significantly between the treated and control groups. In contrast, the treated groups had substantial changes in bodyweight, serum alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), albumin, globulin, albumin/globulin ratio (A/G ratio), triglycerides (TG), low-density lipoproteins (LDL), LDL/HDL ratio, urea, creatinine, and triiodothyronine (T3) levels.

Conclusion

The findings indicate that Aplex and Venera have negative impacts on crucial biochemical and physiological indicators, particularly liver and kidney functioning.

Mulberry leaf (Morus alba L.): A review of its potential influences in mechanisms of action on metabolic diseases

The leaves of Morus alba L. (called Sangye in Chinese, ML), which belong to the genus Morus., are highly valuable edible plants in nutrients and nutraceuticals. In Asian countries including China, Japan and Korea, ML are widely used as functional foods including beverages, noodles and herbal tea because of its biological and nutritional value. Meanwhile, ML-derived products in the form of powders, extracts and capsules are widely consumed as dietary supplements for controlling blood glucose and sugar. Clinical studies showed that ML play an important role in the treatment of metabolic diseases including the diabetes, dyslipidemia, obesity, atherosclerosis and hypertension. People broadly use ML due to their nutritiousness, deliciousness, safety, and abundant active benefits. However, the systematic pharmacological mechanisms of ML on metabolic diseases have not been fully revealed. Therefore, in order to fully utilize and scale relevant products about ML, this review summarizes the up-to-date information about the ML and its constituents effecting on metabolic disease.

New Horizons: Is Obesity a Disorder of Neurotransmission?

Obesity is a disease of the nervous system. While some will view this statement as provocative, others will take it as obvious. Whatever our side is, the pharmacology tells us that targeting the nervous system works for promoting weight loss. It works, but at what cost? Is the nervous system a safe target for sustainable treatment of obesity? What have we learned-and unlearned-about the central control of energy balance in the last few years? Herein we provide a thought-provoking exploration of obesity as a disorder of neurotransmission. We discuss the state of knowledge on the brain pathways regulating energy homeostasis that are commonly targeted in anti-obesity therapy and explore how medications affecting neurotransmission such as atypical antipsychotics, antidepressants, and antihistamines relate to body weight. Our goal is to provide the endocrine community with a conceptual framework that will help expending our understanding of the pathophysiology of obesity, a disease of the nervous system.

Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity.

AIM OF THIS REVIEW

The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org).

RESULTS

Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity.

CONCLUSION

Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

Galla Chinensis, a Traditional Chinese Medicine: Comprehensive review of botany, traditional uses, chemical composition, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Galla chinensis (GC), a traditional Chinese medicine (TCM), has a wide range of pharmacological properties which have been widely used for more than 1400 years. Based on shape, GC is divided into two groups: jiaobei and dubei. It is a bitter, sour, cold and astringent substance which is usually used for treating diarrhea, constipation, bleeding, cough, vomiting, sweating, hemorrhoids, and anal and uterine prolapse. It is distributed in Japan, North Korea, and all parts of China.

AIM OF STUDY

This study was aimed at carrying out a comprehensive overview of the current status of research on Galla chinensis (GC) for better understanding of it characteristics, while providing a clear direction for future studies. It has aroused the interest of researchers, leading to development of medicinal value, expansion of its application, and provision of wider and more effective drug choices. This study was focused on the traditional uses, botany, chemical composition, pharmacology and toxicology of GC. Finally, the study focused on possible future research directions for GC.

MATERIALS AND METHODS

A comprehensive analysis was done based on academic papers, pharmaceutical monographs, ancient medicinal works, and drug standards of China. This review used Galla and Galla chinensis as keywords for retrieval of information on GC from online databases such as PubMed, Elsevier, CNKI, Web of Science, Google Scholar, SCI hub, and Baidu academic.

RESULTS

It was found that the chemical constituents of GC included tannins, phenolic acid, amino acids and fatty acid, with polyphenol compounds (especially tannins and gallic acid) as the distinct components. In vitro and in vivo studies revealed that GC exerted numerous biological effects such as anti-caries, antibacterial, antiviral, anticancer, and antioxidant effects. The therapeutic effect of GC was attributed mainly to the biological properties of its bioactive components.

CONCLUSIONS

GC is an important TCM which has potential benefit in the treatment of a variety of diseases. However, the relationship amongst the structure and biological activity of GC and its components, mechanism of action, toxicity, pharmacokinetics and target organs need to be further studied. Quality control and quality assurance programs for GC need to be further developed. There is need to study the dynamics associated with the accumulation of chemical compounds in GC as well as the original plants and aphid that form GC.

Patient initiation and maintenance of GLP-1 RAs for treatment of obesity

Introduction: Healthcare providers (HCPs) see many patients with obesity-related complications and are therefore well placed to help treat obesity itself. However, limited collated information exists to help HCPs with the practical use of anti-obesity medications (AOMs). We focus on the initiation and maintenance of a glucagon-like peptide-1 receptor agonist (GLP-1 RA) for weight management, liraglutide 3.0 mg. Literature search was conducted between 25-28 November 2019 on PubMed and ClinicalTrials.gov.Areas covered: Clinical trial and real-world data describing weight-loss efficacy, cardiometabolic risk factors, incidence of adverse events (AEs), and persistence are presented to assist HCPs with patient discussions. Practical considerations to overcome barriers to optimal use are provided, equipping HCPs with the information required to aid with adherence to and persistence with AOMs. The use of other GLP-1- RA therapies in obesity is discussed in light of the recent US Food and Drug Administration approval of semaglutide 2.4 mg for weight management.Expert opinion: Liraglutide 3.0 mg provides benefits regarding weight loss and improvements in cardiometabolic risk factors. Promising areas of future research in the field of obesity include dual receptor agonists and the combination of glucagon-like peptide-1 receptor agonists with other molecules.

Novel Hybrid Molecules Based on (-)-Epigallocatechin Gallate as Potent Anti-adipogenic Agents

A series of novel (-)-epigallocatechin gallate (EGCG)-phloroglucinol hybrid compounds 1-4 has been successfully synthesized by employing a simple and efficient methodology using a dielectric barrier discharge (DBD) plasma irradiation. The new hybrid structures were determined by interpretation of spectroscopic data, with the absolute configurations being established by analysis of the circular dichroism (CD) spectra. The novel hybrids 1 and 2 showed highly improved anti-adipogenic potencies toward both pancreatic lipase and preadipocytes differentiation in 3T3-L1 compared to the original EGCG and phloroglucinol. A novel hybrid 1 represent an interesting subclass of anti-adipogenic candidates that need further research.

Anti-obesity potential of Moringa olifera seed extract and lycopene on high fat diet induced obesity in male Sprauge Dawely rats

Present research explored the anti-obesity effect of Moringa olifera seed oil extract and lycopene (LYC). Forty eight male Sprauge Dawely rats were divided equally into 6 groups. Group Ι (C) served as control, group ΙΙ (MC) was given Moringa olifera seed oil extract (800 mg/kg b.wt) for 8 weeks, group ΙΙΙ (LC) was given (20 mg/kg b.wt) LYC for 8 weeks, group ΙV (O) received high fat diet (HFD) for 20 weeks, group Ѵ (MO), was given HFD for 20 weeks and received (800 mg/kg b.wt) Moringa olifera seed oil extract for last 8 weeks and group ѴΙ (LO), received HFD for 20 weeks and was given (20 mg/kg b.wt) LYC for last 8 weeks. Hematology, lipid peroxidation and antioxidants, non-esterified fatty acids (NEFA), glucose, lipid profile, serum liver and kidney biomarkers, inflammatory markers, leptin, resistin and heart fatty acid binding protein (HFABP) were determined. Also histopathology for liver, kidney and aorta were performed besides immunohistochemistry (IHC) for aortic inducible nitric oxide synthase (iNOS). Administration of Moringa olifera seed oil extract and LYC significantly ameliorated the HFD induced hematological and metabolic perturbations as well as reduced leptin and resistin. Both treatments exerted these effects through promotion of antioxidant enzymes and reducing lipid peroxidation as well as inflammatory cytokines along with reduced iNOS protein expression. Administration of Moringa olifera seed oil extract and LYC have anti-obesity potential in HFD induced obesity in male Sprauge Dawely rats.

Brain-Sparing Sympathofacilitators Mitigate Obesity without Adverse Cardiovascular Effects

Anti-obesity drugs in the amphetamine (AMPH) class act in the brain to reduce appetite and increase locomotion. They are also characterized by adverse cardiovascular effects with origin that, despite absence of any in vivo evidence, is attributed to a direct sympathomimetic action in the heart. Here, we show that the cardiac side effects of AMPH originate from the brain and can be circumvented by PEGylation (PEGyAMPH) to exclude its central action. PEGyAMPH does not enter the brain and facilitates SNS activity via theβ₂-adrenoceptor, protecting mice against obesity by increasing lipolysis and thermogenesis, coupled to higher heat dissipation, which acts as an energy sink to increase energy expenditure without altering food intake or locomotor activity. Thus, we provide proof-of-principle for a novel class of exclusively peripheral anti-obesity sympathofacilitators that are devoid of any cardiovascular and brain-related side effects.

Do the Natural Chemical Compounds Interact with the Same Targets of Current Pharmacotherapy for Weight Management?-A Review

BACKGROUND

Obesity has become a worldwide health concern. Pharmacotherapies are now being introduced because lifestyle modifications alone are insufficient for weight management. The treatment outcomes of current approved anti-obesity agents are not satisfying due to drug-related intolerances. And so natural therapies including herbal medicines are popular alternatives for weight reduction; however, there are limited studies about their mechanism of actions.

METHODS

Five databases (PubMed, Scopus, Google Scholar, Science Direct, Proquest) were searched to investigate the targets and safety profiles of the current and past anti-obesity drugs that have been approved by the Food and Drug Administration (FDA) or the European Medicines Agency (EMA) as well as the commonly used off-label agents. The targets for weight-loss natural products and their principle bioactive components have also been searched. Only articles in English were included.

RESULTS

The targets for current anti-obesity single agents include pancreatic lipase, Glucagon Like Peptide-1(GLP-1) receptor, and serotonin 2C (5-HT2C) receptor. Potential targets such as amylin, pancreatic alpha amylase, leptin receptor, melanocortin receptor 4 receptor (MC4R), Peroxisome Proliferator- Activated Receptors gamma (PPAR γ), endocannabinoid 1 (CB1) receptor and Adenosine Monophosphate (AMP)-Activated Protein Kinase (AMPK) were discussed in various studies. Natural compounds have been found to interact with targets like pancreatic lipase, pancreatic alpha amylase, AMPK and PPAR γ to achieve weight reduction.

CONCLUSION

Current pharmacotherapies and natural chemical compounds do act on same targets. Further investigations on the interactions between herbal compounds and the above targets are essential for the development of novel weight-loss therapies.

Genetically Engineered Escherichia coli Nissle 1917 Secreting GLP-1 Analog Exhibits Potential Antiobesity Effect in High-Fat Diet-Induced Obesity Mice

OBJECTIVE

This study aimed to investigate the potential antiobesity effect of genetically modified Escherichia coli Nissle 1917 (EcN-GM) in mice fed a high-fat diet (HFD).

METHODS

The mice were randomly divided into six groups: a normal diet group (ND), a HFD group, a HFD + EcN group, and three HFD + EcN-GM groups. The effects of EcN-GM on body weight, food intake, fat pad and organ weight, and an oral glucose tolerance test were measured, in addition to hepatic biochemistry and histological analysis. The mRNA expression of neuropeptides related to food intake regulation in the hypothalamus was also detected.

RESULTS

The results showed that EcN-GM decreased body weight, body weight gain, food intake, fat pad weight, and hepatic weight of HFD mice. There were beneficial effects of EcN-GM on blood glucose, hepatic biochemistry, and hepatic histological alterations. A dramatic switch of food intake-regulating gene expression in the hypothalamus was also observed in mice.

CONCLUSIONS

This work has revealed that a modified live bacterial therapeutic, EcN-GM, has potential beneficial effects on obesity. This effect may be related to the regulating of the neuropeptide expression of energy intake and expenditure in the hypothalamus. This study demonstrates a successful example of engineered EcN-GM as a novel approach for weight management.

Prominent Pancreatic Lipase Inhibition and Free Radical Scavenging Activity of a Myristica fragrans Ethanolic Extract in vitro. Potential Role in Obesity Treatment

Objective:The objective of the present study was to evaluate the antioxidant and lipase inhibitory potential of various extracts of Myristica fragrans (in vitro). Material and methods:Ethanolic extracts of Myristica fragrans were studied for their free radical scavenging and lipase inhibitory potentials by using porcine lipase, PNPB and DPPH. All results were obtained by applying active formulas and calculating the percentage of inhibition. Results:Among all extracts, Myristica fragrans ethanolic extract has shown the strongest pancreatic lipase inhibitory activity at 100 ìg/mL (66.24%), with the closest potency to tthat of the standard drug, Orlistat (81.57%). This extract has also exhibited a potent antioxidant activity. The findings of the present study clearly showed that DPPH free radical scavenging activity of MFE produced 88% inhibition at 5 mg/mL as compared to standard ascorbic acid, which was 90%. Conclusions:Ethanolic extracts of Myristica fragrans had a marked PL inhibitory action and antioxidant effect. Therefore, based on this research evidence, they could be aternatively used for obesity treatment.

Effect of Myristica fragrans extract on total body composition in cafeteria diet induced obese rats

It is of interest to evaluate the effect of Myristica fragrans on body composition of cafeteria diet induced obese rats. Thirty rats (150-160g) grouped into 5 and each group contains 6 rats. Group-1 was normal control and 2-5 groups were fed with cafeteria diet for 15 weeks to induce obesity. From 16th week to 25th week test drugs were given as mentioned in the experimental protocol. Body weight, BMI, changes in body composition was measured by TOBEC, adipose tissue weights, organ weights, abdominal circumference were measured according to standard methods. After 70days of treatment with MFE 200mg/kg, 400mg/kg Body weight reduced by 9.29%, 12.87% respectively. BMI was also decreased. Abdominal circumference, total fat percentage, organ weights, was substantially reduced. At 400mg/kg of MFE has shown maximum potentiality when compared with 200mg/kg. Orlistat 50mg was used as standard drug. Tetrahydrofuran, flavonoids, saponins, present in Myristica fragrans has shown anti obesity activity. Our findings explain the potentiality of phytochemicals as a potent anti obesity agent, provide scientific evidence for its traditional use and suggest the possible mechanism of action.

Drug Delivery Strategies for the Treatment of Metabolic Diseases

Metabolic diseases occur when normal metabolic processes are disrupted in the human body, which can be congenital or acquired. The incidence of metabolic diseases worldwide has reached epidemic proportions. So far, various methods including systemic drug therapy and surgery are exploited to prevent and treat metabolic diseases. However, current pharmacotherapeutic options for treatment of these metabolic disorders remain limited and ineffective, especially reducing patient compliance to treatment. Therefore, it is desirable to exploit effective drug delivery approaches to effectively treat metabolic diseases and reduce side effects. This brief review summarizes novel delivery strategies including local, targeted, and oral drug delivery strategies, as well as intelligent stimulus-responsive drug delivery strategy, for the treatment of metabolic disorders including diabetes, obesity, and atherosclerosis.

GPCRs in Autocrine and Paracrine Regulations

G protein-coupled receptors (GPCRs) constitute the largest superfamily of integral membrane protein receptors. As signal detectors, the several 100 known GPCRs are responsible for sensing the plethora of endogenous ligands that are critical for the functioning of our endocrine system. Although GPCRs are typically considered as detectors for first messengers in classical signal transduction pathways, they seldom operate in isolation in complex biological systems. Intercellular communication between identical or different cell types is often mediated by autocrine or paracrine signals that are generated upon activation of specific GPCRs. In the context of energy homeostasis, the distinct complement of GPCRs in each cell type bridges the autocrine and paracrine communication within an organ, and the various downstream signaling mechanisms regulated by GPCRs can be integrated in a cell to produce an ultimate output. GPCRs thus act as gatekeepers that coordinate and fine-tune a response. By examining the role of GPCRs in activating and receiving autocrine and paracrine signals, one may have a better understanding of endocrine diseases that are associated with GPCR mutations, thereby providing new insights for treatment regimes.

Ghrelin Stimulates Endothelial Cells Angiogenesis through Extracellular Regulated Protein Kinases (ERK) Signaling Pathway

Adipose tissue is hyper-vascularized. Vessels in adipose tissue not only supply nutrients and oxygen to nourish adipocytes, but also provide cytokines that regulate mass and function of adipose tissue. Understanding the fundamental mechanisms how vessels modulate adipocyte functions would provide new therapeutic options for treatment of metabolic disease and obesity. In recent years, researches about ghrelin are focused on glucose and lipid metabolism, but its effect on vascular function remains uncharacterized. In the present study, ghrelin receptor gene deletion mice (Ghsr^-/- mice) were used to study ghrelin-regulated vascular metabolism in white adipose tissue. Ghsr^-/- mice demonstrated lower food intake, lower body weight, and resistance to high-fat diet-induced obesity. The number of vessels in white adipose tissue was decreased in Ghsr^-/- mice when compared with wild type mice fed with high-fat diet. To further define ghrelin effects in vitro, we used endothelial progenitor cells from wild type and Ghsr^-/- mice as well as human umbilical vein endothelial cells in our experiments. We found that ghrelin stimulated endothelial cells angiogenesis and migration through the MEK-ERK signaling pathway. [d-Lys3]-GHRP-6 and PD98059 could reverse the effects of ghrelin on endothelial cells. Our study indicates that ghrelin activates its receptor on endothelial cells to promote angiogenesis and migration via a mechanism involving the extracellular regulated protein kinases (ERK) signaling pathway.

Sympathetic inputs regulate adaptive thermogenesis in brown adipose tissue through cAMP-Salt inducible kinase axis

Various physiological stimuli, such as cold environment, diet, and hormones, trigger brown adipose tissue (BAT) to produce heat through sympathetic nervous system (SNS)- and β-adrenergic receptors (βARs). The βAR stimulation increases intracellular cAMP levels through heterotrimeric G proteins and adenylate cyclases, but the processes by which cAMP modulates brown adipocyte function are not fully understood. Here we described that specific ablation of cAMP production in brown adipocytes led to reduced lipolysis, mitochondrial biogenesis, uncoupling protein 1 (Ucp1) expression, and consequently defective adaptive thermogenesis. Elevated cAMP signaling by sympathetic activation inhibited Salt-inducible kinase 2 (Sik2) through protein kinase A (PKA)-mediated phosphorylation in brown adipose tissue. Inhibition of SIKs enhanced Ucp1 expression in differentiated brown adipocytes and Sik2 knockout mice exhibited enhanced adaptive thermogenesis at thermoneutrality in an Ucp1-dependent manner. Taken together, our data indicate that suppressing Sik2 by PKA-mediated phosphorylation is a requisite for SNS-induced Ucp1 expression and adaptive thermogenesis in BAT, and targeting Sik2 may present a novel therapeutic strategy to ramp up BAT thermogenic activity in humans.

Simple Analysis of Lipid Inhibition Activity on an Adipocyte Micro-Cell Pattern Chip

Polydimethyl-siloxane (PDMS) is often applied to fabricate cell chips. In this study, we fabricated an adipocyte microcell pattern chips using PDMS to analyze the inhibition activity of lipid droplets in mouse embryo fibroblast cells (3T3-L1) with anti-obesity agents. To form the PDMS based micropattern, we applied the micro-contact printing technique using PDMS micro-stamps that had been fabricated by conventional soft lithography. This PDMS micro-pattern enabled the selective growth of 3T3-L1 cells onto the specific region by preventing cell adhesion on the PDMS region. It then allowed growth of the 3T3-L1 cells in the chip for 10 days and confirmed that lipid droplets were formed in the 3T3-L1 cells. After treatment of orlistat and quercetin were treated in an adipocyte micro-cell pattern chip with 3T3-L1 cells for six days, we found that orlistat and quercetin exhibited fat inhibition capacities of 19.3% and 24.4% from 0.2 μM of lipid droplets in 3T3-L1 cells. In addition, we conducted a direct quantitative analysis of 3T3-L1 cell differentiation using Oil Red O staining. In conclusion, PDMS-based adipocyte micro-cell pattern chips may contribute to the development of novel bioactive compounds.

Circulating molecules that control brown/beige adipocyte differentiation and thermogenic capacity

Obesity may be counteracted by increased energy expenditure. Circulating molecules act in the adipose tissue to influence brown and beige adipocyte function, differentiation, and thermogenic capacity, which in turn affects substrate utilization and impacts energy balance at the organismal level. These molecules have been envisioned as biomarkers and potential candidates for pharmacological interventions to treat obesity. Here we summarize studies that demonstrate the roles of endogenous circulating molecules of a wide variety in regulating the thermogenic potential of brown and beige fat cells. This review describes the state-of-the-art in the field and helps researchers to prioritize their targets in future studies.

Human brown adipose tissue-function and therapeutic potential in metabolic disease

There has been a resurgence of interest in brown adipose tissue (BAT) over the last decade. Key to this has been our ability to accurately image it, which has improved significantly. The role of BAT in regulating energy expenditure is important, and its pharmacological manipulation may hold therapeutic potential in metabolic disease. There is ample evidence of BAT activation by cold exposure, and pharmacological utilisation of similar pathways, using B3 receptor agonists holds promise since the development of selective agonists with limited cross-reactivity has rekindled interest. Endogenous agents like irisin, FGF21 and certain gut hormones may hold value as BAT activators. Other agents such as steroid hormones may also hold therapeutic potential, although short-term worsening of metabolic profile remains problematic. Clearly, pharmacological manipulation of BAT is important, and thanks to recent advances we may one day be able to add such agents to our anti-obesity arsenal.

Further brominated polyacetylenes with pancreatic lipase inhibitory activity from Chinese marine sponge Xestospongia testudinaria

A new brominated polyacetylene, xestonariene I (1), along with three known related analogues (2-4), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and by comparison with literature data. Compound 4 exhibited significant inhibitory activity against pancreatic lipase, which plays a key role in preventing obesity, with an IC₅₀ value of 0.61 μM, being comparable to that of the positive control orlistat (IC₅₀ = 0.78 μM).

Total control of fat cells from adipogenesis to apoptosis using a xanthene analog

Overcrowded adipocytes secrete excess adipokines and cytokines under stress, which results in a deregulated metabolism. This negative response to stress increases the possibility of obesity and several of its associated diseases, such as cancer and atherosclerosis. Therefore, a reduction in the number of adipocytes may be a rational strategy to relieve the undesired expansion of adipose tissue. A newly synthesized xanthene analog, MI-401, was found to have two distinct effects on the regulation of the adipocyte’s life cycle. MI-401 efficiently down regulated the expression of transcription factors, PPARγ and C/EBPα, and lipogenesis proteins, FAS and FABP4. This down regulation resulted in the inhibition of adipogenesis. Without newly differentiated adipocytes, the total number of adipocytes will not increase. In addition to this inhibitory effect, MI-401 was able to actively kill mature adipocytes. It specifically triggered apoptosis in adipocytes at low micro molar concentration and spared preadipocytes and fibroblasts. These dual functionalities make MI-401 an effective agent in the regulation of the birth and death of adipocytes.

Medical Weight Loss Treatment Options in Obese Solid-Organ Transplant Candidates

With the increasing incidence of obesity in our country, the rate of obesity seen in organ transplant candidates is also rising. Accurate descriptions and measures of weight and degree of obesity vary between organ systems. Weight loss can be achieved in some patients while they wait for the transplant surgery. Weight reduction in transplant candidates involves a team approach, with a program of education and support, including medical nutrition therapy, physical therapy, and psychological support. The safety and applicability of weight loss medications to assist with pretransplant weight loss is also not well understood. It is not yet well known if weight loss before transplantation will improve posttransplant outcomes. Many questions regarding the treatment of obesity in transplant candidates remain unanswered.

4-Hydroxyisoleucine from Fenugreek (Trigonella foenum-graecum): Effects on Insulin Resistance Associated with Obesity

Obesity and insulin resistance (IR) are interdependent multifactorial processes that cannot be understood separately. Obesity leads to systemic inflammation and increased levels of free fatty acids that provoke IR and lipotoxicity. At the same time, IR exacerbates adipose cell dysfunction, resulting in chronic inflammation and major lipotoxic effects on nonadipose tissues. 4-Hydroxyisoleucine (4-OHIle), a peculiar nonprotein amino acid isolated from fenugreek (Trigonella foenum-graecum) seeds, exhibits interesting effects on IR related to obesity. 4-OHIle increases glucose-induced insulin release, and the insulin response mediated by 4-OHIle depends on glucose concentration. The beneficial effects observed are related to the regulation of blood glucose, plasma triglycerides, total cholesterol, free fatty acid levels, and the improvement of liver function. The mechanism of action is related to increased Akt phosphorylation and reduced activation of Jun N-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB. Here, we present a review of the research regarding the insulinotropic and insulin-sensitising activity of 4-OHIle in in vitro and in vivo models.

Transcriptome Profile Reveals that Pu-Erh Tea Represses the Expression of Vitellogenin Family to Reduce Fat Accumulation in Caenorhabditis elegans

Due to misbalanced energy surplus and expenditure, obesity has become a common chronic disorder that is highly associated with many metabolic diseases. Pu-erh tea, a traditional Chinese beverage, has been believed to have numerous health benefits, such as anti-obesity. However, the underlying mechanisms of its anti-obesity effect are yet to be understood. Here, we take the advantages of transcriptional profile by RNA sequencing (RNA-Seq) to view the global gene expression of Pu-erh tea. The model organism Caenorhabditis elegans was treated with different concentrations of Pu-erh tea water extract (PTE, 0 g/mL, 0.025 g/mL, and 0.05 g/mL). Compared with the control, PTE indeed decreases lipid droplets size and fat accumulation. The high-throughput RNA-Sequence technique detected 18073 and 18105 genes expressed in 0.025 g/mL and 0.05 g/mL PTE treated groups, respectively. Interestingly, the expression of the vitellogenin family (vit-1, vit-2, vit-3, vit-4 and vit-5) was significantly decreased by PTE, which was validated by qPCR analysis. Furthermore, vit-1(ok2616), vit-3(ok2348) and vit-5(ok3239) mutants are insensitive to PTE triggered fat reduction. In conclusion, our transcriptional profile by RNA-Sequence suggests that Pu-erh tea lowers the fat accumulation primarily through repression of the expression of vit(vitellogenin) family, in addition to our previously reported (sterol regulatory element binding protein) SREBP-SCD (stearoyl-CoA desaturase) axis.

Measuring the Pharmacokinetic Properties of Drugs with a Novel Surgical Rat Model

Purpose/aim of the study: The pharmacokinetic (PK) parameters in animal models can help optimize novel candidate drugs prior to human trials. However, due to the complexity of pharmacokinetic experiments, their use is limited in academia. We present a novel surgical rat model for investigation of pharmacokinetic parameters and its use in an anti-obesity drug development program.

MATERIALS AND METHODS

The model uses anesthetized male Wistar rats, a jugular, a femoral catheter, and an insulin pump for peptide infusion. The following pharmacokinetic parameters were measured: metabolic clearance rate (MCR), half-life, and volume of distribution (Vd). Glucagon-like peptide 1 (GLP-1), glucagon (GCG), and exendin-4 (Ex-4) were used to validate the model. The pharmacokinetic parameters of anti-obesity drug candidates X1, X2, and X3 were measured.

RESULTS

GLP-1 had a significantly higher MCR (83.9 ± 14.1 mL/min/kg) compared to GCG (40.7 ± 14.3 mL/min/kg) and Ex-4 (10.1 ± 2.5 mL/min/kg) (p < .01 and p < .001 respectively). Ex-4 had a statistically significant longer half-life (35.1 ± 7.4 min) compared to both GCG (3.2 ± 1.7 min) and GLP-1 (1.2 ± 0.4 min) (p < .01 for both GCG and GLP-1). Ex-4 had a statistically significant higher volume of distribution (429.7 ± 164.9 mL/kg) compared to both GCG (146.8 ± 49.6 mL/kg) and GLP-1 (149.7 ± 53.5 mL/kg) (p < .01 for both GCG and GLP-1). Peptide X3 had a statistically significant longer half-life (21.3 ± 3.5 min) compared to both X1 (3.9 ± 0.4 min) and X2 (16.1 ± 2.8 min) (p < .001 for both X1 and X2).

CONCLUSIONS

We present an affordable and easily accessible platform for the measurement of PK parameters of peptides. This novel surgical rat model produces consistent and reproducible results while minimizing animal use.

Curcumin Mimics the Neurocognitive and Anti-Inflammatory Effects of Caloric Restriction in a Mouse Model of Midlife Obesity

Dietary curcumin was studied for its potential to decrease adiposity and reverse obesity- associated cognitive impairment in a mouse model of midlife sedentary obesity. We hypothesized that curcumin intake, by decreasing adiposity, would improve cognitive function in a manner comparable to caloric restriction (CR), a weight loss regimen. 15-month-old male C57BL/6 mice were assigned in groups to receive the following dietary regimens for 12 weeks: (i) a base diet (Ain93M) fed ad libitum (AL), (ii) the base diet restricted to 70% of ad libitum (CR) or (iii) the base diet containing curcumin fed AL (1000 mg/kg diet, CURAL). Blood markers of inflammation, interleukin 6 (IL-6) and C-reactive protein (CRP), as well as an indicator of redox stress (GSH: GSSG ratio), were determined at different time points during the treatments, and visceral and subcutaneous adipose tissue were measured upon completion of the experiment. After 8 weeks of dietary treatment, the mice were tested for spatial cognition (Morris water maze) and cognitive flexibility (discriminated active avoidance). The CR group showed significant weight loss and reduced adiposity, whereas CURAL mice had stable weight throughout the experiment, consumed more food than the AL group, with no reduction of adiposity. However, both CR and CURAL groups took fewer trials than AL to reach criterion during the reversal sessions of the active avoidance task, suggesting an improvement in cognitive flexibility. The AL mice had higher levels of CRP compared to CURAL and CR, and GSH as well as the GSH: GSSG ratio were increased during curcumin intake, suggesting a reducing shift in the redox state. The results suggest that, independent of their effects on adiposity; dietary curcumin and caloric restriction have positive effects on frontal cortical functions that could be linked to anti-inflammatory or antioxidant actions.

Anti-obesity effects of Yerba Mate (Ilex Paraguariensis): a randomized, double-blind, placebo-controlled clinical trial

Background

Obesity is a major health problem. A food field research that has recently aroused considerable interest is the potential of natural products to counteract obesity. Yerba Mate may be helpful in reducing body weight and fat. The aim of this study was to investigate the efficacy and safety of Yerba Mate supplementation in Korean subjects with obesity.

Methods

A randomized, double-blind, placebo-controlled trial was conducted. Subjects with obesity (body mass index (BMI) ≥ 25 but < 35 kg/m² and waist-hip ratio (WHR) ≥ 0.90 for men and ≥ 0.85 for women) were given oral supplements of Yerba Mate capsules (n = 15) or placebos (n = 15) for 12 weeks. Subjects take three capsules per each meal, total three times in a day (3 g/day). Measured outcomes were efficacy (abdominal fat distribution, anthropometric parameters and blood lipid profiles) and safety (adverse events, laboratory test results and vital signs).

Results

During 12 weeks of Yerba Mate supplementation, decreases in body fat mass (P = 0.036) and percent body fat (P = 0.030) compared to the placebo group were statistically significant. WHR was significantly decreased (P = 0.004) in the Yerba Mate group compared to the placebo group. No clinically significant changes in any safety parameters were observed.

Conclusions

Yerba Mate supplementation decreased body fat mass, percent body fat and WHR. Yerba Mate was a potent anti-obesity reagent that did not produce significant adverse effects. These results suggested that Yerba Mate supplementation may be effective for treating obese individuals.

Trial registration

ClinicalTrials.gov: (NCT01778257)

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0859-1) contains supplementary material, which is available to authorized users.

Using Animal Models to Determine the Role of Gustatory Neural Input in the Control of Ingestive Behavior and the Maintenance of Body Weight

INTRODUCTION

Decades of research have suggested that nutritional intake contributes to the development of human disease, mainly by influencing the development of obesity and obesity-related conditions. A relatively large body of research indicates that functional variation in human taste perception can influence nutritional intake as well as body mass accumulation. However, there are a considerable number of studies that suggest that no link between these variables actually exists. These discrepancies in the literature likely result from the confounding influence of a variety of other, uncontrolled, factors that can influence ingestive behavior.

STRATEGY

In this review, the use of controlled animal experimentation to alleviate at least some of these issues related to the lack of control of experimental variables is discussed. Specific examples of the use of some of these techniques are examined.

DISCUSSION AND CONCLUSIONS

The review will close with some specific suggestions aimed at strengthening the link between gustatory neural input and its putative influence on ingestive behaviors and the maintenance of body weight.