Berberine activates thermogenesis in white and brown adipose tissue

Huanglian-Jiedu decoction promotes adipose thermogenesis in obese mice by suppressing the expression of HDAC3

ETHNOPHARMACOLOGICAL RELEVANCE

Huanglian Jiedu Decoction (HLJDD) is an ancient formula of traditional Chinese medicine that is commonly utilized in a range of disorders, and it has been shown to have pharmacological effects on glucose and lipid metabolism. However, the specific mechanism of HLJDD for the treatment of obesity and related metabolic disorders remains to be further investigated.

AIM OF THE STUDY

It has been thought that encouraging adipose thermogenesis to raise the body's energy expenditure is a useful tactic for improving metabolic abnormalities and losing weight. In this study, we investigated the ability and underlying mechanisms of HLJDD to regulate fat cell thermogenesis to improve energy expenditure in obesity.

METHODS

The obese mouse model was established on a high-fat diet for 12 weeks. All mice were divided into NC, HFD, HFD with HLJDD of a low dose (2.25 g/kg/d), and HFD with HLJDD of a high dose (4.5 g/kg/d) groups and kept for 4 weeks. In vitro experiments were conducted to evaluate the effects of 5% and 10% HLJDD-containing serum on differentiated 3T3-L1 cells and HDAC3-knocking-down 3T3-L1 cells.

RESULTS

The results showed that HLJDD treatment significantly improved glucose and insulin tolerance and decreased the adipocyte radius of WATs, as well as increased energy consumption in obese mice. Besides, HLJDD treatment dramatically increased the levels of thermogenic genes UCP-1 and PGC-1α while suppressing HDAC3 levels in WATs and 3T3-L1 adipocytes. Importantly, the effects of HLJDD on PGC-1α and UCP-1 were blocked in HDAC3 knockdown adipocytes.

CONCLUSIONS

Therefore, these results suggest that HLJDD enhanced adipose thermogenesis and improved energy expenditure by inhibiting HDAC3, thereby increasing UCP-1 and PGC-1α expression. These findings amplified the mechanisms of HLJDD and its potential to treat obesity and related metabolic disorders.

Intracerebroventricular prokineticin 2 infusion may play a role on the hypothalamus-pituitary-thyroid axis and energy metabolism

AIM

The hypothesis of this study is to determine the effects of intracerebroventricular (icv) prokineticin 2 infusion on food consumption and body weight and to elucidate whether it has effects on energy expenditure via the hypothalamus-pituitary-thyroid (HPT) axis in adipose tissue.

MATERIAL AND METHODS

A total of 40 rats were used in the study and 4 groups were established: Control, Sham, Prokineticin 1.5 and Prokineticin 4.5 (n=10). Except for the Control group, rats were treated intracerebroventricularly via osmotic minipumps, the Sham group was infused with aCSF (vehicle), and the Prokineticin 1.5 and Prokineticin 4.5 groups were infused with 1.5 nMol and 4.5 nMol prokineticin 2, respectively. Food and water consumption and body weight were monitored during 7-day infusion in all groups. At the end of the infusion, the rats were decapitated and serum TSH, fT4 and fT3 levels were determined by ELISA. In addition, PGC-1α and UCP1 gene expression levels in white adipose tissue (WAT) and brown adipose tissue (BAT), TRH from rat hypothalamic tissue were determined by real-time PCR.

RESULTS

Icv prokineticin 2 (4.5 nMol) infusion had no effect on water consumption but reduced daily food consumption and body weight (p<0.05). Icv prokineticin 2 (4.5 nMol) infusion significantly increased serum TSH, fT4 and fT3 levels when compared to Control and Sham groups (p<0.05). Also, icv prokineticin 2 (4.5 nMol) infusion increased the expression of TRH in the hypothalamus tissue and expression of PGC-1α UCP1 in the WAT and BAT (p<0.05).

CONCLUSION

Icv prokineticin 2 (4.5 nMol) infusion may suppress food consumption via its receptors in the hypothalamus and reduce body weight by stimulating energy expenditure and thermogenesis in adipose tissue through the HPT axis.

Innovative treatments for obesity and NAFLD: A bibliometric study on antioxidants, herbs, phytochemicals, and natural compounds

The increasing scientific interest in antioxidants and naturally derived compounds as potential remedies for obesity and non-alcoholic fatty liver disease (NAFLD) has led to extensive research. The objective of this bibliometric analysis is to present an updated perspective on the topic of antioxidants, herbs, phytochemicals, and natural compounds, in the control of obesity and NAFLD, to identify new areas for future research. Publications from the years 2012-2022 were retrieved using the Scopus database. The research trends were analyzed using the Biblioshiny and VOSviewer tools. The field has seen a significant increase in research activity, as indicated by an annual growth rate of 10 % in the number of published manuscripts. China, Korea, and the USA emerged as the most prominent contributors in this specific field, supported by their notable volumes of publications and citations. The density analysis revealed that the most frequently occurring authors' keywords related to herbal species are, in rank order, Camelia sinensis, Momordica charantia, Curcuma longa, Ilex paraguariensis, Panax ginseng, Moringa oleifera, Garcinia cambogia, Garcinia mangostana, Zingiber officinale, and Cinnamomum verum. In the group of antioxidants, phytochemicals, and natural compounds, the top 10 were resveratrol, curcumin, quercetin, vitamin E, alpha-lipoic acid, vitamin C, chlorogenic acid, lycopene, fucoxanthin, and berberine. The co-occurrence analysis unveiled significant themes and potential trends, including a notable interest in the impact of herbal species, antioxidants, phytochemicals, and natural compounds on obesity and NAFLD through the modulation of the gut microbiome. Another recurring theme that arises, is the ongoing investigation of molecular targets that demonstrate anti-adipogenesis properties. The analysis presented in this study provides valuable insights for researchers investigating the efficacy of antioxidants, herbs, phytochemicals, and natural compounds in addressing obesity and NAFLD. Through the use of bibliometric methods, the study offers a comprehensive overview. Furthermore, the findings of this analysis can serve as a foundation for future research in this specific domain.

Berberine attenuates TNBS-induced colitis in mice by improving the intestinal microbiota

Objective

To investigate the effects of berberine (BBR) as a treatment on intestinal microecological alterations and enteritis in mice produced by TNBS.

Methods

There were seven mice per group: seven in the healthy group (Ctrl), seven in the TNBS-induced enteritis group (TNBS), and seven in the berberine treatment group (BBR). The mice were weighed, slaughtered after 7 days, and subjected to high-throughput intestinal microecological analysis by Illumina, as well as haematological detection and imaging evaluation of colon pathology.

Results

The alterations in colon length, immune cell subpopulations, inflammatory factors, and intestinal microecology of mice induced by BBR were refined using a battery of experiments and observations. According to intestinal microecological studies, BBR can increase the number of bacteria, including Lactobacillus, Verrucomicrobia, Bacteroides, and Akkermansia muciniphila.

Conclusion

BBR has a therapeutic effect on TNBS-induced colitis in mice, which is associated with modifications in immune cell subpopulations and intestinal microecology. It also offers a viable approach as a prospective probiotic (like Akkermansia muciniphila) to IBD therapy in clinical settings.

Interplay of FXN expression and lipolysis in white adipocytes plays a critical role in insulin sensitivity in Friedreich's ataxia mouse model

Frataxin (FXN) is required for iron-sulfur cluster biogenesis, and its loss causes the early-onset neurodegenerative disease Friedreich ataxia (FRDA). Loss of FXN is a susceptibility factor in the development of diabetes, a common metabolic complication after myocardial hypertrophy in patients with FRDA. The underlying mechanism of FXN deficient-induced hyperglycemia in FRDA is, however, poorly understood. In this study, we confirmed that the FXN deficiency mouse model YG8R develops insulin resistance in elder individuals by disturbing lipid metabolic homeostasis in adipose tissues. Evaluation of lipolysis, lipogenesis, and fatty acid β-oxidation showed that lipolysis is most severely affected in white adipose tissues. Consistently, FXN deficiency significantly decreased expression of lipolytic genes encoding adipose triglyceride lipase (Atgl) and hormone-sensitive lipase (Hsl) resulting in adipocyte enlargement and inflammation. Lipolysis induction by fasting or cold exposure remarkably upregulated FXN expression, though FXN deficiency lessened the competency of lipolysis compared with the control or wild type mice. Moreover, we found that the impairment of lipolysis was present at a young age, a few months earlier than hyperglycemia and insulin resistance. Forskolin, an activator of lipolysis, or pioglitazone, an agonist of PPARγ, improved insulin sensitivity in FXN-deficient adipocytes or mice. We uncovered the interplay between FXN expression and lipolysis and found that impairment of lipolysis, particularly the white adipocytes, is an early event, likely, as a primary cause for insulin resistance in FRDA patients at later age.

Adipocyte-Targeted Nanocomplex with Synergistic Photothermal and Pharmacological Effects for Combating Obesity and Related Metabolic Syndromes

Obesity is a global epidemic which induces a multitude of metabolic disorders. Browning of white adipose tissue (WAT) has emerged as a promising therapeutic strategy for promoting weight loss and improving associated metabolic syndromes in people with obesity. However, current methods of inducing white adipose tissue browning have limited applicability. We developed a nanocomplex pTSL@(P+I), which is a temperature-sensitive liposome (TSL) surface-conjugated with an adipocyte-targeting peptide (p) and loaded with both browning-promoting agents (P) and photosensitizing agents (I). This nanocomplex exhibits adipocyte targeting, as well as synergistic pharmacological and photothermal properties to promote browning. pTSL@(P+I) effectively upregulates UCP1 and COX5B expression by activating the transcription axis of PPARγ/PGC1α and HSF1/PGC1α, thereby promoting white adipose tissue browning and reducing obesity. This novel nanocomplex exhibited a uniform spherical shape, with an average diameter of approximately 200 nm. Additionally, the nanocomplexes exhibited remarkable photothermal properties and biocompatibility. Further, when adipocytes were treated with pTSL@(P+I), their triglyceride content decreased remarkably and intracellular mitochondrial activity increased significantly. When applied to diet-induced obesity (DIO) mice, the nanocomplex exhibited significant efficacy, demonstrating a notable 14.4% reduction in body weight from the initial measurement, a decreased fat/lean mass ratio of 20.8%, and no statistically significant disparities (p > 0.05) in associated side effects when compared to the control group. In summary, implementation of the targeted nanocomplex pTSL@(P+I) to enhance energy expenditure by stimulating white adipose tissue browning offers a promising therapeutic approach for the treatment of obesity and related metabolic syndromes.

Butein derivatives prevent obesity and improve insulin resistance through the induction of energy expenditure in high-fat diet-fed obese mice

Obesity is a global public health problem and is related with fatal diseases such as cancer and cardiovascular and metabolic diseases. Medical and lifestyle-related strategies to combat obesity have their limitations. White adipose tissue (WAT) browning is a promising strategy for increasing energy expenditure in individuals with obesity. Uncoupling protein 1 (UCP1) drives WAT browning. We previously screened natural products that enable induction of Ucp1 and demonstrated that these natural products induced WAT browning and increased energy expenditure in mice with diet-induced obesity. In this study, we aimed to extensively optimise the structure of compound 1, previously shown to promote WAT browning. Compound 3 s exhibited a significantly higher ability to induce Ucp1 in white and brown adipocytes than did compound 1. A daily injection of compound 3 s at 5 mg/kg prevented weight gain by 13.6 % in high-fat diet-fed mice without any toxicological observation. In addition, compound 3 s significantly improved glucose homeostasis, decreased serum triacylglycerol levels, and reduced total cholesterol and LDL cholesterol levels, without altering dietary intake or physical activity. Pharmaceutical properties such as solubility, lipophilicity, and membrane permeability as well as metabolic stability, half-life (T1/2), and blood exposure ratio of i.p to i.v were significantly improved in compound 3 s when compared with those in compound 1. Regarding the mode of action of WAT browning, the induction of Ucp1 and Prdm4 by compounds 1 and 3 s was dependent on Akt1 in mouse embryonic fibroblasts. Therefore, this study suggests the potential of compound 3 s as a therapeutic agent for individuals with obesity and related metabolic diseases, which acts through the induction of WAT browning as well as brown adipose tissue activation.

Tetrahydroberberrubine exhibits preventive effect on obesity by activating PGC1α-mediated thermogenesis in white and brown adipose tissue

The escalating prevalence of obesity presents formidable challenges, necessitating the development of effective therapeutic strategies. In this study, we aimed to elucidate the preventive effects on obesity of tetrahydroberberrubine (THBru), a derivative of berberine (BBR) and to unravel its underlying mechanism. Using an obese mouse model induced by a high-fat diet (HFD), THBru was found to markedly ameliorate obesity, as evidenced by reduced body weight, decreased Lee's index, diminished fat mass in epididymal white adipose tissue (WAT) and brown adipose tissue (BAT), alongside improved dyslipidemia. Notably, at the same dose, THBru exhibited superior efficacy compared to BBR. RNA-sequencing and gene set enrichment analysis indicated THBru activated thermogenesis, which was further confirmed in WAT, BAT, and 3T3-L1 cells. Bioinformatics analysis of RNA-sequencing data revealed the candidate gene Pgc1α, a key regulator involved in thermogenesis. Moreover, THBru was demonstrated to elevate the expression of PGC1α by stabilizing its mRNA in WAT, BAT and 3T3-L1 cells. Furthermore, PGC1α knockdown blocked the pro-thermogenic and anti-obesity action of THBru both in vivo and in vitro. This study unravels the preventive effects of THBru on obesity through the activation of PGC1α-mediated thermogenesis, thereby delineating its potential therapeutic implications for obesity and associated disorders.

A combination of Citrus aurantifolia fruit rind and Theobroma cacao seed extracts supplementation enhances metabolic rates in overweight subjects: a randomized, placebo-controlled, cross-over study

Background and objective

LN19183 is a proprietary, synergistic combination of Citrus aurantifolia fruit rind and Theobroma cacao seed extracts that increased resting energy expenditure (REE) in high-fat diet (HFD)-fed obese rats. The objective of this study was to validate the thermogenic potential of LN19183 in obese Sprague Dawley (SD) rats and to assess its clinical efficacy in a proof-of-concept, randomized, placebo-controlled, cross-over human trial.

Methods

In the rat study, HFD-fed obese rats were supplemented with either HFD alone or with 45, 90, or 180 mg LN19183 per kg body weight (BW) for 28 days. In the human study, 60 overweight adults (male and female, aged 20-39 years) were randomized. Subjects took LN19183 (450 mg) or a matched placebo capsule on two consecutive days in phases one and two of the study, separated by a 10-day washout period. In each phase, on day 1, REE at pre-dose, 60-, 120-, and 180-min post-dose, and on day 2, metabolic rates at pre-dose and post-dose during and 20 min after exercise were measured using indirect calorimetry.

Results

In rats, LN19183 significantly increased REE, reduced BW gain and fat masses, and increased fat and carbohydrate metabolism marker proteins including beta 3 adrenergic receptor (β3-AR), phospho-AMP-activated protein kinase (AMPK), glucagon-like peptide-1 receptor (GLP-1R) in the liver, and serum adiponectin levels. Furthermore, LN19183-supplemented human volunteers increased (P < 0.05, vs. placebo) the metabolic rates at rest and with exercise; their fat oxidation was increased (P < 0.05, vs. placebo) at rest and 20 min post-exercise. The groups' systolic and diastolic blood pressure (BP), heart rates (HR), and safety parameters were comparable.

Conclusion

These observations suggest that LN19183 is a thermogenic botanical composition with no stimulatory effects on BP and HR.

Mitochondrial UCP1: Potential thermogenic mechanistic switch for the treatment of obesity and neurodegenerative diseases using natural and epigenetic drug candidates

BACKGROUND

Brown fat is known to provide non-shivering thermogenesis through mitochondrial uncoupling mediated by uncoupling protein 1 (UCP1). Non-shivering is not dependent on UCP2, UCP4, and BMCP1/UCP5 genes, which are distinct from UCP1 in a way that they are not constitutive uncouplers. Although they are susceptible to free fatty acid and free radical activation, their functioning has a significant impact on the performance of neurons.

METHODOLOGY

Using subject-specific keywords (Adipose tissue; Adipocytes; Mitochondria; Obesity; Thermogenesis; UCP's in Neurodegeneration; Alzheimer's disease; Parkinson's disease), research articles and reviews were retrieved from Web of Science, ScienceDirect, Google Scholar, and PubMed. This article includespublications published between 2018 and 2023. The drugs that upregulate UCP1 are included in the study while the drugs that do not impact UCP1 are were not included.

RESULTS

Neuronal UCPs have a direct impact on synaptic plasticity, neurodegenerative processes, and neurotransmission, by modulating calcium flux, mitochondrial biogenesis, local temperature, and free radical generation. Numerous significant advances in the study of neuronal UCPs and neuroprotection are still to be made. Identification of the tissue-dependent effects of UCPs is essential first. Pharmacologically targeting neuronal UCPs is a key strategy for preventing both neurodegenerative diseases and physiological aging. Given that UCP2 has activities that are tissue-specific, it will be essential to develop treatments without harmful side effects. The triggering of UCPs by CoQ, an essential cofactor, produces nigral mitochondrial uncoupling, reduces MPTP-induced toxicity, and may even decrease the course of Parkinson's disease, according to early indications.

CONCLUSION

Herein, we explore the potential of UCP1 as a therapeutic target for treating obesity, neurodegenerative diseases as well as a potential activator of both synthetic and natural drugs. A deeper knowledge of synaptic signaling and neurodegeneration may pave the way to new discoveries regarding the functioning and controlling of these genes.

Weighing in on the role of brown adipose tissue for treatment of obesity

Brown adipose tissue (BAT) activation is an emerging target for obesity treatments due to its thermogenic properties stemming from its ability to shuttle energy through uncoupling protein 1 (Ucp1). Recent rodent studies show how BAT and white adipose tissue (WAT) activity can be modulated to increase the expression of thermogenic proteins. Consequently, these alterations enable organisms to endure cold-temperatures and elevate energy expenditure, thereby promoting weight loss. In humans, BAT is less abundant in obese subjects and impacts of thermogenesis are less pronounced, bringing into question whether energy expending properties of BAT seen in rodents can be translated to human models. Our review will discuss pharmacological, hormonal, bioactive, sex-specific and environmental activators and inhibitors of BAT to determine the potential for BAT to act as a therapeutic strategy. We aim to address the feasibility of utilizing BAT modulators for weight reduction in obese individuals, as recent studies suggest that BAT's contributions to energy expenditure along with Ucp1-dependent and -independent pathways may or may not rectify energy imbalance characteristic of obesity.

Molecular mechanisms, targets and clinical potential of berberine in regulating metabolism: a review focussing on databases and molecular docking studies

Background: Metabolic imbalance is the common basis of many diseases. As natural isoquinoline alkaloid, berberine (BBR) has shown great promise in regulating glucose and lipids metabolism and treating metabolic disorders. However, the related mechanism still lacks systematic research. Aim: To discuss the role of BBR in the whole body's systemic metabolic regulation and further explore its therapeutic potential and targets. Method: Based on animal and cell experiments, the mechanism of BBR regulating systemic metabolic processes is reviewed. Potential metabolism-related targets were summarized using Therapeutic Target Database (TTD), DrugBank, GeneCards, and cutting-edge literature. Molecular modeling was applied to explore BBR binding to the potential targets. Results: BBR regulates the whole-body metabolic response including digestive, circulatory, immune, endocrine, and motor systems through adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR), sirtuin (SIRT)1/forkhead box O (FOXO)1/sterol regulatory element-binding protein (SREBP)2, nuclear factor erythroid 2-related factor (Nrf) 2/heme oxygenase (HO)-1, and other signaling pathways. Through these reactions, BBR exerts hypoglycemic, lipid-regulating, anti-inflammatory, anti-oxidation, and immune regulation. Molecular docking results showed that BBR could regulate metabolism targeting FOXO3, Nrf2, NAD(P)H quinone oxidoreductase 1 (NQO1), glutathione peroxidase (Gpx) 4 and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA). Evaluating the target clinical effects, we found that BBR has the therapeutic potential of anti-aging, anti-cancer, relieving kidney disease, regulating the nervous system, and alleviating other chronic diseases. Conclusion: This review elucidates the interaction between potential targets and small molecular metabolites by exploring the mechanism of BBR regulating metabolism. That will help pharmacologists to identify new promising metabolites interacting with these targets.

Mulberry leaf and its effects against obesity: A systematic review of phytochemistry, molecular mechanisms and applications

BACKGROUND

Obesity and hyperlipidemia can induce a variety of diseases, and have become major health problems worldwide. How to effectively prevent and control obesity has become one of the hot-spots of contemporary research. Mulberry leaf is the dried leaf of Morus alba L., which is approved by the Ministry of Health as a "homology of medicine and food", rich in diverse active constituents and with a variety of health effects including anti-obesity and anti-hyperlipidemia activities.

PURPOSE

The review attempts to summarize and provide the molecular basis, mechanism, safety and products for further exploration and application of mulberry leaf on the treatment on the control of weight gain and obesity.

METHODS

This review is conducted by using ScienceDirect, PubMed, CNKI and Web of Science databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Based on the research progress of domestic and foreign scholars, the effective phytochemicals, molecular mechanisms and product applications of mulberry leaf in the prevention and treatment of obesity and related metabolic diseases were summarized.

CONCLUSION

Mulberry leaf has excellent medicinal and health care value in obesity treatment. However, its pharmacodynamic substance basis and molecular mechanisms need to be further studied.

AMPK as a mediator of tissue preservation: time for a shift in dogma?

Ground-breaking discoveries have established 5'-AMP-activated protein kinase (AMPK) as a central sensor of metabolic stress in cells and tissues. AMPK is activated through cellular starvation, exercise and drugs by either directly or indirectly affecting the intracellular AMP (or ADP) to ATP ratio. In turn, AMPK regulates multiple processes of cell metabolism, such as the maintenance of cellular ATP levels, via the regulation of fatty acid oxidation, glucose uptake, glycolysis, autophagy, mitochondrial biogenesis and degradation, and insulin sensitivity. Moreover, AMPK inhibits anabolic processes, such as lipogenesis and protein synthesis. These findings support the notion that AMPK is a crucial regulator of cell catabolism. However, studies have revealed that AMPK's role in cell homeostasis might not be as unidirectional as originally thought. This Review explores emerging evidence for AMPK as a promoter of cell survival and an enhancer of anabolic capacity in skeletal muscle and adipose tissue during catabolic crises. We discuss AMPK-activating interventions for tissue preservation during tissue wasting in cancer-associated cachexia and explore the clinical potential of AMPK activation in wasting conditions. Overall, we provide arguments that call for a shift in the current dogma of AMPK as a mere regulator of cell catabolism, concluding that AMPK has an unexpected role in tissue preservation.

Tussilagone ameliorates high-fat diet-induced hepatic steatosis by enhancing energy metabolism and antioxidant activity

Non-alcoholic fatty liver disease (NAFLD) is a major health problem. However, no effective treatments are currently available. Thus, there is a critical need to develop novel drugs that can prevent and treat NAFLD with few side effects. In this study, Tussilagone (TUS), a natural sesquiterpene isolated from Tussilago farfara L, was explored in vitro and in vivo for its potential to treat NAFLD. Our results showed that in vitro TUS reduced oleic acid palmitate acid-induced triglyceride and cholesterol synthesis in HepG2cells, reduced intracellular lipid droplet accumulation, improved glucose metabolism disorders and increased energy metabolism and reduced oxidative stress levels. In vivo, TUS significantly reduced fat accumulation and improved liver injury in high-fat diet (HFD)-induced mice. TUS treatment significantly increased liver mitochondrial counts and antioxidant levels compared to the HFD group of mice. In addition, TUS was found to reduce the expression of genes involved in lipid synthesis sterol regulatory element binding protein-1 (SREBP1), fatty acid synthase (FASN), and stearoy-CoA desaturase 1 (SCD1) in vitro and in vivo. Our results suggest that TUS may be helpful in the treatment of NAFLD, suggesting that TUS is a promising compound for the treatment of NAFLD. Our findings provided novel insights into the application of TUS in regulating lipid metabolism.

Unveiling the Potential of Natural Compounds: A Comprehensive Review on Adipose Thermogenesis Modulation

The process of adipocyte browning has recently emerged as a novel therapeutic target for combating obesity and obesity-related diseases. Non-shivering thermogenesis is the process of biological heat production in mammals and is primarily mediated via brown adipose tissue (BAT). The recruitment and activation of BAT can be induced through chemical drugs and nutrients, with subsequent beneficial health effects through the utilization of carbohydrates and fats to generate heat to maintain body temperature. However, since potent drugs may show adverse side effects, nutritional or natural substances could be safe and effective as potential adipocyte browning agents. This review aims to provide an extensive overview of the natural food compounds that have been shown to activate brown adipocytes in humans, animals, and in cultured cells. In addition, some key genetic and molecular targets and the mechanisms of action of these natural compounds reported to have therapeutic potential to combat obesity are discussed.

Coffee, tea, and cocoa in obesity prevention: Mechanisms of action and future prospects

Obesity, a major public health problem, causes numerous complications that threaten human health and increase the socioeconomic burden. The pathophysiology of obesity is primarily attributed to lipid metabolism disorders. Conventional anti-obesity medications have a high abuse potential and frequently deliver insufficient efficacy and have negative side-effects. Hence, functional foods are regarded as effective alternatives to address obesity. Coffee, tea, and cocoa, three widely consumed beverages, have long been considered to have the potential to prevent obesity, and several studies have focused on their intrinsic molecular mechanisms in past few years. Therefore, in this review, we discuss the mechanisms by which the bioactive ingredients in these three beverages counteract obesity from the aspects of adipogenesis, lipolysis, and energy expenditure (thermogenesis). The future prospects and challenges for coffee, tea, and cocoa as functional products for the treatment of obesity are also discussed, which can be pursued for future drug development and prevention strategies against obesity.

The molecular mechanism of macrophage-adipocyte crosstalk in maintaining energy homeostasis

Interactions between macrophages and adipocytes in adipose tissue are critical for the regulation of energy metabolism and obesity. Macrophage polarization induced by cold or other stimulations can drive metabolic reprogramming of adipocytes, browning, and thermogenesis. Accordingly, investigating the roles of macrophages and adipocytes in the maintenance of energy homeostasis is critical for the development of novel therapeutic approaches specifically targeting macrophages in metabolic disorders such as obesity. Current review outlines macrophage polarization not only regulates the release of central nervous system and inflammatory factors, but controls mitochondrial function, and other factor that induce metabolic reprogramming of adipocytes and maintain energy homeostasis. We also emphasized on how the adipocytes conversely motivate the polarization of macrophage. Exploring the interactions between adipocytes and macrophages may provide new therapeutic strategies for the management of obesity-related metabolic diseases.

An update on the secretory functions of brown, white, and beige adipose tissue: Towards therapeutic applications

Adipose tissue, including white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, is vital in modulating whole-body energy metabolism. While WAT primarily stores energy, BAT dissipates energy as heat for thermoregulation. Beige adipose tissue is a hybrid form of adipose tissue that shares characteristics with WAT and BAT. Dysregulation of adipose tissue metabolism is linked to various disorders, including obesity, type 2 diabetes, cardiovascular diseases, cancer, and infertility. Both brown and beige adipocytes secrete multiple molecules, such as batokines, packaged in extracellular vesicles or as soluble signaling molecules that play autocrine, paracrine, and endocrine roles. A greater understanding of the adipocyte secretome is essential for identifying novel molecular targets in treating metabolic disorders. Additionally, microRNAs show crucial roles in regulating adipose tissue differentiation and function, highlighting their potential as biomarkers for metabolic disorders. The browning of WAT has emerged as a promising therapeutic approach in treating obesity and associated metabolic disorders. Many browning agents have been identified, and nanotechnology-based drug delivery systems have been developed to enhance their efficacy. This review scrutinizes the characteristics of and differences between white, brown, and beige adipose tissues, the molecular mechanisms involved in the development of the adipocytes, the significant roles of batokines, and regulatory microRNAs active in different adipose tissues. Finally, the potential of WAT browning in treating obesity and atherosclerosis, the relationship of BAT with cancer and fertility disorders, and the crosstalk between adipose tissue with circadian system and circadian disorders are also investigated.

Mitophagy suppression by miquelianin-rich lotus leaf extract induces 'beiging' of white fat via AMPK/DRP1-PINK1/PARKIN signaling axis

BACKGROUND

Lotus (Nelumbo nucifera) leaf has been described to have anti-obesity activity, but the role of white fat 'browning' or 'beiging' in its beneficial metabolic actions remains unclear. Here, 3T3-L1 cells and high-fat-diet (HFD)-fed mice were used to evaluate the effects of miquelianin-rich lotus leaf extract (LLE) on white-to-beige fat conversion and its regulatory mechanisms.

RESULTS

Treatment with LLE increased mitochondrial abundance, mitochondrial membrane potential and NAD+ /NADH ratio in 3T3-L1 cells, suggesting its potential in promoting mitochondrial activity. qPCR and/or western blotting analysis confirmed that LLE induced the expression of beige fat-enriched gene signatures (e.g. Sirt1, Cidea, Dio2, Prdm16, Ucp1, Cd40, Cd137, Cited1) and mitochondrial biogenesis-related markers (e.g. Nrf1, Cox2, Cox7a, Tfam) in 3T3-L1 cells and inguinal white adipose tissue of HFD-fed mice. Furthermore, we found that LLE treatment inhibited mitochondrial fission protein DRP1 and blocked mitophagy markers such as PINK1, PARKIN, BECLIN1 and LC-3B. Chemical inhibition experiments revealed that AMPK/DRP1 signaling was required for LLE-induced beige fat formation via suppressing PINK1/PARKIN/mitophagy.

CONCLUSION

Our data reveal a novel mechanism underlying the anti-obesity effect of LLE, namely the induction of white fat beiging via AMPK/DRP1/mitophagy signaling. © 2023 Society of Chemical Industry.

Natural Products in the Modulation of Farnesoid X Receptor Against Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a global health concern with a high prevalence and increasing economic burden, but official medicine remains unavailable. Farnesoid X receptor (FXR), a nuclear receptor member, is one of the most promising drug targets for NAFLD therapy that plays a crucial role in modulating bile acid, glucose, and lipid homeostasis, as well as inhibits hepatic inflammation and fibrosis. However, the rejection of the FXR agonist, obecholic acid, by the Food and Drug Administration for treating hepatic fibrosis raises a question about the functions of FXR in NAFLD progression and the therapeutic strategy to be used. Natural products, such as FXR modulators, have become the focus of attention for NAFLD therapy with fewer adverse reactions. The anti-NAFLD mechanisms seem to act as FXR agonists and antagonists or are involved in the FXR signaling pathway activation, indicating a promising target of FXR therapeutic prospects using natural products. This review discusses the effective mechanisms of FXR in NAFLD alleviation, and summarizes currently available natural products such as silymarin, glycyrrhizin, cycloastragenol, berberine, and gypenosides, for targeting FXR, which can facilitate development of naturally targeted drug by medicinal specialists for effective treatment of NAFLD.

A Synergistic Botanical Composition Increases Resting Energy Expenditure and Reduces Adiposity in High-Fat Diet-Fed Rats

OBJECTIVE

An imbalance between dietary energy intake and energy expenditure may result in body fat gain or obesity. Increasing resting energy expenditure (REE) is an attractive strategy for managing body fat gain. The objective of the current study was to generate proof-of-concept data on a synergistic composition (LN19183) of Citrus aurantifolia fruit rind (CA) and Theobroma cacao seed (TC) extracts to increase REE and reduce body fat gain in a high-fat diet (HFD)-fed rats.

METHOD

In in vitro cell-based experiments, CA, TC, or LN19183 were tested for fibroblast growth factor 21 (FGF-21) production from 3T3-L1 mouse adipocytes. Uncoupling protein 1 (UCP-1) and beta3-adrenergic receptor (β3-AR) protein expressions in LN19183-treated 3T3-L1 lysates were also tested. The 56-day in vivo study in male Sprague Dawley (SD) rats (age: 12-14 weeks; body weight [b.w.]: 115-197 g) contained 2 phases of 28 days each of induction and supplementation. Seven rats received a regular rodent diet (RD) over 56 days. In the induction phase, 21 rats received HFD; in the supplementation phase, the obese rats (n = 7) received either HFD alone or in concurrence with a daily oral dose of either 100 or 250 mg/kg b.w. of LN19183 for 28 days.

RESULTS

In 3T3-L1 adipocytes, LN19183 synergistically increased FGF-21 production and dose-dependently increased β3-AR and UCP-1 protein expression. In HFD-fed rats, both doses of LN19183 supplementation significantly (p < 0.05) decreased the body weight gain, total fat mass, and liver weight and increased (p < 0.05) REE. High-dose LN19183 also significantly (p < 0.05) increased fat oxidation and UCP-1 protein expression in white fat tissue and reduced liver triglyceride (TG) level. LN19183-supplemented groups substantially reduced serum TG and glucose levels compared to the HFD rats.

CONCLUSIONS

LN19183 reduces body fat mass and weight gain via increased REE and fat oxidation in HFD-fed obese rats.

Natural Extracts for Antibacterial Applications

Bacteria-induced epidemics and infectious diseases are seriously threatening the health of people around the world. In addition, antibiotic therapy has been inducing increasingly more serious bacterial resistance, which makes it urgent to develop new treatment strategies to combat bacteria, including multidrug-resistant bacteria. Natural extracts displaying antibacterial activity and good biocompatibility have attracted much attention due to greater concerns about the safety of synthetic chemicals and emerging drug resistance. These antibacterial components can be isolated and utilized as antimicrobials, as well as transformed, combined, or wrapped with other substances by using modern assistive technologies to fight bacteria synergistically. This review summarizes recent advances in natural extracts from three kinds of sources-plants, animals, and microorganisms-for antibacterial applications. This work discusses the corresponding antibacterial mechanisms and the future development of natural extracts in antibacterial fields.

Berberine Metabolites Stimulate GLP-1 Secretion by Alleviating Oxidative Stress and Mitochondrial Dysfunction

Berberine (BBR) is a principal component of Rhizoma coptidis known for its therapeutic potential in treating diseases such as type 2 diabetes mellitus (T2DM) and obesity. Despite the trace levels of BBR in plasma, it's believed that its metabolites play a pivotal role in its biological activities. While BBR is recognized to promote GLP-1 production in intestinal L cells, the cytoprotective effects of its metabolites on these cells are yet to be explored. The present study investigates the effects of BBR metabolites on GLP-1 secretion and the underlying mechanisms. Our results revealed that, out of six BBR metabolites, berberrubine (BBB) and palmatine (PMT) significantly increased the production and glucose-stimulated secretion of GLP-1 in GLUTag cells. Notably, both BBB and PMT could facilitate GLP-1 and insulin secretion and enhance glucose tolerance in standard mice. Moreover, a single dose of PMT could markedly increase plasma GLP-1 and improve glucose tolerance in mice with obesity induced by a high-fat diet. In palmitic acid or TNF[Formula: see text]-treated GLUTag cells, BBB and PMT alleviated cell death, oxidative stress, and mitochondrial dysfunction. Furthermore, they could effectively reverse inflammation-induced inhibition of the Akt signaling pathway. In general, these insights suggest that the beneficial effects of orally administered BBR on GLP-1 secretion are largely attributed to the pharmacological activity of BBB and PMT by their above cytoprotective effects on L cells, which provide important ideas for stimulating GLP-1 secretion and the treatment of T2DM.

Berberine promotes lacteal junction zippering and ameliorates diet-induced obesity through the RhoA/ROCK signaling pathway

BACKGROUND

Obesity has emerged as a global epidemic. Recent research has indicated that diet-induced obesity can be prevented by promoting lacteal junction zippering. Berberine, which is derived from natural plants, is found to be promising in weight reduction, but the underlying mechanism remains unspecified.

PURPOSE

To determine whether berberine protects against obesity by regulating the lacteal junction and to explore potential molecular mechanisms.

METHODS

Following the induction of the diet-induced obese (DIO) model, mice were administered low and high doses of berberine for 4 weeks. Indicators associated with insulin resistance and lipid metabolism were examined. Various methods, such as Oil Red O staining, transmission electron microscopy imaging, confocal imaging and others were used to observe the effects of berberine on lipid absorption and the lacteal junction. In vitro, human dermal lymphatic endothelial cells (HDLECs) were used to investigate the effect of berberine on LEC junctions. Western Blot and immunostaining were applied to determine the expression levels of relevant molecules.

RESULTS

Both low and high doses of berberine reduced body weight in DIO mice without appetite suppression and ameliorated glucolipid metabolism disorders. We also found that the weight loss effect of berberine might contribute to the inhibition of small intestinal lipid absorption. The possible mechanism was related to the promotion of lacteal junction zippering via suppressing the ras homolog gene family member A (RhoA)/Rho-associated kinase (ROCK) signaling pathway. In vitro, berberine also promoted the formation of stable mature junctions in HDLECs, involving the same signaling pathway.

CONCLUSION

Berberine could promote lacteal junction zippering and ameliorate diet-induced obesity through the RhoA/ROCK signaling pathway.

Electroacupuncture Mediates Fat Metabolism and Autophagy via a Sirt3-Dependent Mechanism in Mice Fed High-Fat Diet

This study investigates the therapeutic potential of electroacupuncture (EA) on obesity, focusing on its influence on autophagy and energy metabolism, utilizing a high-fat diet (HFD)-induced mouse model. Treatment with EA significantly reduces body weight, fat deposition, and lipid accumulation in HFD-fed mice. Additionally, EA effectively ameliorates metabolic imbalances, reducing blood glucose levels and plasma markers of liver function. At the molecular level, EA enhances the expression of thermogenesis-associated genes in brown adipose tissue and decreases p53 expression, suggesting a decrease in apoptosis. Autophagy in white adipose tissue is inhibited by EA, as demonstrated by the suppression of key autophagy-related proteins. Further experiments highlight the critical role of Sirtuin 3 (Sirt3) in EA's anti-obesity effects. Sirt3 supplementation combined with EA results in reduced body weight, fat deposition, and lipid accumulation, along with modulations in key metabolic indicators. Moreover, EA's modulatory effect on uncoupling protein 1 (Ucp1), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α), and p53 is found to be Sirt3 dependent. In conclusion, EA exerts beneficial effects against obesity through Sirt3-dependent modulation of autophagy and energy metabolism, indicating a potential therapeutic approach for obesity and related metabolic disorders.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

Berberine-silybin salt achieves improved anti-nonalcoholic fatty liver disease effect through regulating lipid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine (BBR) and silybin (SIY) are natural compounds obtained from Berberidaceae members and Silybum marianum (L.) Gaertn., respectively. These compounds have been demonstrated to regulate lipid metabolism and indue hepatoprotective effects, establishing their importance for the treatment of liver injury. Combination therapy has shown promise in treating ailments with complex pathophysiology, such as liver diseases. However, the inconsistent dissolution and poor absorption of BBR and SIY limit their efficacy.

AIM OF THE STUDY

This study compared the salt formulation (BSS) and physical mixture (BSP) of BBR and SIY for their efficacy in treating nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

The formation of the BSS was confirmed using various techniques, including nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and powder X-ray diffractometry. In addition, dissolution, trans-epithelial permeability, and bioavailability experiments were conducted to evaluate the absorption and distribution of drugs. Pharmacodynamics and mechanisms were investigated through in vivo experiments.

RESULTS

BSS form demonstrated synchronized dissolution of both components, unlike BSP. Additionally, the transepithelial permeability results revealed that BSS exhibited superior penetration and absorption of both BBR and SIY in comparison to BSP. Furthermore, BSS significantly increased the bioavailability of SIY in both plasma and the liver (2.2- and 4.5-fold, respectively) when compared with BSP. Moreover, BSS demonstrated a more potent inhibitory effect on lipid production in HepG2 cells than BSP. In mouse models (BALB/c) of NAFLD, BSS improved disease outcomes, as evidenced by decreased adipose levels, normalized blood lipid levels, and reduced liver parenchyma injury. Preliminary transcriptomics analysis suggested that BSS achieved its anti-NAFLD effect by regulating the expression of fatty acid transporter CD36, recombinant fatty acid binding protein 4, and stearyl coenzyme A dehydrogenase 1, which are associated with the synthesis and uptake of fatty acid-related proteins.

CONCLUSIONS

The study demonstrated that compared with physical mixing, salification improved the efficacy of BBR and SIY, as demonstrated in animal experiments. These findings provide valuable insights into the development of more effective treatments for NAFLD and provide new possibilities for combination therapies.

Sophoridine Counteracts Obesity via Src-Mediated Inhibition of VEGFR Expression and PI3K/AKT Phosphorylation

Sophoridine (SRP) is a natural quinolizidine alkaloid found in many traditional Chinese herbs, though its effect on adipose tissue is unclear. We improved serum lipid levels by administering SRP by gavage in high-fat diet (HFD)-fed C57BL/6 mice. After 11 weeks, SRP supplementation significantly reduced body weight gain and improved glucose homeostasis, while reducing subcutaneous fat and liver weight. SRP also inhibited cell proliferation and differentiation of 3T3-L1 cells. Proteomics analysis revealed that SRP inhibits adipocyte differentiation by interacting with Src, thereby suppressing vascular endothelial growth factor receptor 2 (VEGFR2) expression and PI3K/AKT phosphorylation. This study provides an empirical basis for the treatment of obesity with small molecules.

Antiobesity Drug Discovery Research: In vitro Models for Shortening the Drug Discovery Pipeline

Obesity is a growing global health problem, leading to various chronic diseases. Despite standard treatment options, the prevalence of obesity continues to rise, emphasizing the need for new drugs. in vitro methods of drug discovery research provide a time and cost-saving platform to identify new antiobesity drugs. The review covers various aspects of obesity and drug discovery research using in vitro models. Besides discussing causes, diagnosis, prevention, and treatment, the review focuses on the advantages and limitations of in vitro studies and exhaustively covers models based on enzymes and cell lines from different animal species and humans. In contrast to conventional in vivo animal investigations, in vitro preclinical tests using enzyme- and cell line-based assays provide several advantages in development of antiobesity drugs. These methods are quick, affordable, and provide high-throughput screening. They can also yield insightful information about drug-target interactions, modes of action, and toxicity profiles. By shedding light on the factors that lead to obesity, in vitro tests can also present a chance for personalized therapy. Technology will continue to evolve, leading to the creation of more precise and trustworthy in vitro assays, which will become more and more crucial in the search for novel antiobesity medications.

DHA alleviated hepatic and adipose inflammation with increased adipocyte browning in high-fat diet-induced obese mice

Obesity is associated with accumulation of inflammatory immune cells in white adipose tissue, whereas thermogenic browning adipose tissue is inhibited. Dietary fatty acids are important nutritional components and several clinical and experimental studies have reported beneficial effects of docosahexaenoic acid (DHA) on obesity-related metabolic changes. In this study, we investigated effects of DHA on hepatic and adipose inflammation and adipocyte browning in high-fat diet-induced obese C57BL/6J mice, and in vitro 3T3-L1 preadipocyte differentiation. Since visceral white adipose tissue has a close link with metabolic abnormality, epididymal adipose tissue represents current target for evaluation. A course of 8-week DHA supplementation improved common phenotypes of obesity, including improvement of insulin resistance, inhibition of macrophage M1 polarization, and preservation of macrophage M2 polarization in hepatic and adipose tissues. Moreover, dysregulated adipokines and impaired thermogenic and browning molecules, considered obesogenic mechanisms, were improved by DHA, along with parallel alleviation of endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and mitochondrial DNA stress-directed innate immunity. During 3T3-L1 preadipocytes differentiation, DHA treatment decreased lipid droplet accumulation and increased the levels of thermogenic, browning, and mitochondrial biogenesis molecules. Our study provides experimental evidence that DHA mitigates obesity-associated inflammation and induces browning of adipose tissue in visceral epididymal adipose tissue. Since obesity is associated with metabolic abnormalities across tissues, our findings indicate that DHA may have potential as part of a dietary intervention to combat obesity.

Hydroxy-α-sanshool from the fruits of Zanthoxylum bungeanum Maxim. promotes browning of white fat by activating TRPV1 to induce PPAR-γ deacetylation

BACKGROUND

Accumulating evidence suggested increasing energy expenditure is a feasible strategy for combating obesity, and browning of white adipose tissue (WAT) to promote thermogenesis might be one of the attractive ways. Hydroxy-α-sanshool (HAS), a natural amide alkaloid extracted from the fruits of Zanthoxylum bungeanum Maxim, possesses lots of benefits in lipid metabolism regulation.

METHODS

The anti-obesity effect of HAS was investigated by establishing an animal model of obesity and a 3T3-L1 differentiation cell model. Effects of HAS on the whole-body fat and liver of obese mice, and the role of HAS in inducing browning of white fat were studied by Micro CT, Metabolic cage detection, Cell mitochondrial pressure detection, transmission electron microscopy and cold exposure assays. Furthermore, the Real-time PCR (qPCR), digital PCR (dPCR), western blot, Co-immunoprecipitation (Co-IP), molecular docking, drug affinity responsive target stability (DARTS), Cellular thermal shift assay (CETSA) and other methods were used to investigate the target and mechanisms of HAS.

RESULTS

We found that treatment with HAS helped mice combat obesity caused by a high fat diet (HFD) and improve metabolic characteristics. In addition, our results suggested that the anti-obesity effect of HAS is related to increase energy consumption and thermogenesis via induction of browning of WAT. The further investigations uncovered that HAS can up-regulate UCP-1 expression, increase mitochondria number, and elevate the cellular oxygen consumption rates (OCRs) of white adipocytes. Importantly, the results indicated that browning effects of HAS is closely associated with SIRT1-dependent PPAR-γ deacetylation through activating the TRPV1/AMPK pathway, and TRPV1 is the potential drug target of HAS for the browning effects of WAT.

CONCLUSIONS

Our results suggested the HAS can promote browning of WAT via regulating AMPK/SIRT-1/PPARγ signaling, and the potential drug target of HAS is the membrane receptor of TRPV1.

Berberine protects mice against type 2 diabetes by promoting PPARγ-FGF21-GLUT2-regulated insulin sensitivity and glucose/lipid homeostasis

Type 2 diabetes (T2D) is a chronic, burdensome disease that is characterized by disordered insulin sensitivity and disturbed glucose/lipid homeostasis. Berberine (BBR) has multiple therapeutic actions on T2D, including regulation of glucose and lipid metabolism, improvement of insulin sensitivity and energy expenditure. Recently, the function of BBR on fibroblast growth factor 21 (FGF21) has been identified. However, if BBR ameliorates T2D through FGF21, the underlying mechanisms remain unknown. Herein, we used T2D wild type (WT) and FGF21 global knockout (FKO) mice [mouse T2D model: established by high-fat diet (HFD) feeding plus streptozotocin (STZ) injection], and hepatocyte-specific peroxisome proliferator activated receptor γ (PPARγ) deficient (PPARγHepKO) mice, and cultured human liver carcinoma cells line, HepG2 cells, to characterize the role of BBR in glucose/lipid metabolism and insulin sensitivity. We found that BBR activated FGF21 expression by up-regulating PPARγ expression at the cellular level. Meanwhile, BBR ameliorated glucosamine hydrochloride (Glcn)-induced insulin resistance and increased glucose transporter 2 (GLUT2) expression in a PPARγ/FGF21-dependent manner. In T2D mice, BBR up-regulated the expression of PPARγ, FGF21 and GLUT2 in the liver, and GLUT2 in the pancreas. BBR also reversed T2D-induced insulin resistance, liver lipid accumulation, and damage in liver and pancreas. However, FGF21 deficiency diminished these effects of BBR on diabetic mice. Altogether, our study demonstrates that the therapeutic effects of BBR on T2D were partly accomplished by activating PPARγ-FGF21-GLUT2 signaling pathway. The discovery of this new pathway provides a deeper understanding of the mechanism of BBR for T2D treatment.

The Hepatic Antisteatosis Effect of Xanthohumol in High-Fat Diet-Fed Rats Entails Activation of AMPK as a Possible Protective Mechanism

Obesity is the leading cause of non-alcoholic fatty liver disease by provoking hyperglycemia, hyperlipidemia, insulin resistance, oxidative stress, and inflammation. Low activity of AMP-activated protein kinase (AMPK) is linked to obesity, liver injury, and NAFLD. This study involves examining if the anti-steatosis effect of Xanthohumol (XH) in high-fat diet (HFD)-fed rats involves the regulation of AMPK. Adult male rats were divided into five groups (n = 8 each) as control (3.85 kcal/g); XH (control diet + 20 mg/kg), HFD (4.73 kcl/g), HFD + XH (20 mg/kg), and HFD + XH (30 mg/kg) + compound c (cc) (0.2 mg/kg). All treatments were conducted for 12 weeks. Treatment with XH attenuated the gain in body weight, fat pads, fasting glucose, and insulin in HFD rats. It also lowered serum leptin and free fatty acids (FFAs) and improved glucose and insulin tolerances in these rats. It also attenuated the increase in serum livers of liver marker enzymes and reduced serum and hepatic levels of triglycerides (TGs), cholesterol (CHOL), FFAs, as well as serum levels of low-density lipoproteins cholesterol (LDL-c) oxidized LDL-c. XH also reduced hepatic levels of malondialdehyde (MDA), nuclear accumulation of NF-κB, and the levels of tumor necrosis-factor-α (TNF-α) and interleukin-6 (IL-6) while stimulating the nuclear levels of Nrf2 and total levels of glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in these HFD-fed rats. At the molecular levels, XH increased hepatic mRNA expression and phosphorylation of AMPK (Thr72) and reduced the expression of lipogenic genes SREBP1c and ACC-1. In concomitance, XH reduced hepatic liver droplet accumulation, reduced the number of apoptotic nuclei, and improved the structures of nuclei, mitochondria, and rough endoplasmic reticulum. Co-treatment with CC, an AMPK inhibitor, completely abolished all these effects of XH. In conclusion, XH attenuates obesity and HFD-mediated hepatic steatosis by activating hepatic AMPK.

Efficacy and underlying mechanisms of berberine against lipid metabolic diseases: a review

Lipid-lowering therapy is an important tool for the treatment of lipid metabolic diseases, which are increasing in prevalence. However, the failure of conventional lipid-lowering drugs to achieve the desired efficacy in some patients, and the side-effects of these drug regimens, highlight the urgent need for novel lipid-lowering drugs. The liver and intestine are important in the production and removal of endogenous and exogenous lipids, respectively, and have an important impact on circulating lipid levels. Elevated circulating lipids predisposes an individual to lipid deposition in the vascular wall, affecting vascular function. Berberine (BBR) modulates liver lipid production and clearance by regulating cellular targets such as cluster of differentiation 36 (CD36), acetyl-CoA carboxylase (ACC), microsomal triglyceride transfer protein (MTTP), scavenger receptor class B type 1 (SR-BI), low-density lipoprotein receptor (LDLR), and ATP-binding cassette transporter A1 (ABCA1). It influences intestinal lipid synthesis and metabolism by modulating gut microbiota composition and metabolism. Finally, BBR maintains vascular function by targeting proteins such as endothelial nitric oxide synthase (eNOS) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). This paper elucidates and summarizes the pharmacological mechanisms of berberine in lipid metabolic diseases from a multi-organ (liver, intestine, and vascular system) and multi-target perspective.

Adipose Tissue Targeting Ultra-Small Hybrid Nanoparticles for Synergistic Photodynamic Therapy and Browning Induction in Obesity Treatment

Photodynamic therapy (PDT), as a means of locally and rapidly inducing adipocyte death via light illumination, in combination with adipose browning induction, a more gradual and widespread effect that could transform white adipose tissue into thermogenic adipose tissue, manifests a promising approach to combat obesity. Herein, adipose-targeting ultra-small hybrid nanoparticles (Pep-PPIX-Baic NPs) composed of an adipose-targeting peptide, Fe3+ , a photosensitizer (protoporphyrin IX), and a browning agent (baicalin) are introduced. Pep-PPIX-Baic NPs have been designed to simultaneously enhance the photodynamic effect and induce browning. After intravenous injection in obese mice, the hybrid nanoparticles can specifically accumulate in white adipose tissues, especially those rich in blood supply, and drive adipose reduction owing to the synergy of the PDT effect and baicalin browning induction. Overall, Pep-PPIX-Baic NPs exhibited superior anti-obesity potential through PDT synergistic with adipose browning induction. The designed multifunctional adipose-targeting hybrid nanoparticles present a prospective nanoplatform for obesity treatment.

lncRNA Hnscr Regulates Lipid Metabolism by Mediating Adipocyte Lipolysis

Obesity is a process of fat accumulation due to the imbalance between energy intake and consumption. Long noncoding RNA (lncRNA) Hnscr is crucial for metabolic regulation, but its roles in lipid metabolism during obesity are still unknown. In this article, we found that the expression of Hnscr gradually decreased in adipose tissues of diet-induced obese mice. Furthermore, the deletion of Hnscr promoted an increase in body weight and adipose tissue weight by upregulating the expression of lipogenesis genes and downregulating lipolysis genes in inguinal white adipose tissue (iWAT) and brown adipose tissue. In vitro knockdown of Hnscr in adipocytes resulted in reduced lipolysis of adipocytes. Overexpression of Hnscr by adenovirus or drug mimics showed the opposite. Mechanistically, Hnscr regulated adipose lipid metabolism by mediating the cyclic adenosine monophosphate/protein kinase A signaling pathway. This study identifies the initial characterization of Hnscr as a critical modifier that regulates lipid metabolism, suggesting that lncRNA Hnscr is a potential target for treating obesity.

Mulberry leaf flavonoids activate BAT and induce browning of WAT to improve type 2 diabetes via regulating the AMPK/SIRT1/PGC-1α signaling pathway

Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, specifically mulberry leaf flavonoids (MLFs), exhibit pronounced potential in the amelioration of type 2 diabetes (T2D). This potential is attributed to their ability to safeguard pancreatic β cells, enhance insulin resistance, and inhibit α-glucosidase activity. Our antecedent research findings underscore the substantial therapeutic efficacy of MLFs in treating T2D. However, the precise mechanistic underpinnings of MLF's anti-T2D effects remain the subject of inquiry. Activation of brown/beige adipocytes is a novel and promising strategy for T2D treatment. In the present study, our primary objective was to elucidate the impact of MLFs on adipose tissue browning in db/db mice and 3T3-L1 cells and elucidate its underlying mechanism. The results manifested that MLFs reduced body weight and food intake, alleviated hepatic steatosis, improved insulin sensitivity, and increased lipolysis and thermogenesis in db/db mice. Moreover, MLFs activated brown adipose tissue (BAT) and induced the browning of inguinal white adipose tissue (IWAT) and 3T3-L1 adipocytes by increasing the expressions of brown adipocyte marker genes and proteins such as uncoupling protein 1 (UCP1) and beige adipocyte marker genes such as transmembrane protein 26 (Tmem26), thereby promoting mitochondrial biogenesis. Mechanistically, MLFs facilitated the activation of BAT and the induction of WAT browning to ameliorate T2D primarily through the activation of AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway. These findings highlight the unique capacity of MLF to counteract T2D by enhancing BAT activation and inducing browning of IWAT, thereby ameliorating glucose and lipid metabolism disorders. As such, MLFs emerge as a prospective and innovative browning agent for the treatment of T2D.

Konjac glucomannan attenuate high-fat diet-fed obesity through enhancing β-adrenergic-mediated thermogenesis in inguinal white adipose tissue in mice

Konjac glucomannan (KGM) has been reported to prevent high-fat diet-induced obesity, and we study investigated whether dietary supplementation with KGM can prevent obesity by increasing energy expenditure in inguinal white adipose tissue (iWAT) of high-fat diet (HF) -fed mice. Weaned mice fed the control diet (Con), HF, or HF plus KGM (8%, w/w, HFK) were divided into three groups. The results showed that 10-week supplementation with KGM significantly reduced partial adipose tissue weight and body weight, and improved glucose tolerance. Compared to the HF group, plasma lipid concentrations in the HFK group were greatly decreased to the control level. Moreover, transcriptomic research has shown that genes that are mainly associated with energy and lipid metabolism are significantly altered in iWAT. Mechanistically, KGM stimulated thermogenesis by promoting the expression of uncoupling protein-1 (UCP1) and the β3-adrenergic receptor (ADR3β). Taken together, our results suggest that dietary supplementation with konjac glucomannan can effectively alleviate obesity induced by a high-fat diet by activating ADR3β-mediated iWAT thermogenesis. Dietary supplementation with KGM can effectively alleviate high fat diet- induced obesity mice by via activating ADR3β-mediated thermogenesis of iWAT.

RNA-Seq transcriptomic landscape profiling of spontaneously hypertensive rats treated with a sodium-glucose cotransporter 2 (SGLT2) inhibitor

BACKGROUND

Sodium-glucose co-transporter-2 inhibitor (SGLT2i) are antihyperglycemic medications that reduce cardiovascular disease (CVD) and improve chronic kidney disease prognosis in patients with diabetes mellitus. The specific impact of SGLT2i treatment on hypertensive individuals, however, remains to be established. This underscores the need for systematic efforts to profile the molecular landscape associated with SGLT2i administration.

METHODS

We conducted a detailed RNA-sequencing (RNA-Seq)-based exploration of transcriptomic changes in response to empagliflozin in eight different tissues (i.e., atrium, aorta, ventricle, white adipose, brown adipose, kidney, lung, and brain) from a male rat model of spontaneously hypertension. Corresponding computational analyses (i.e., clustering, differentially-expressed genes [DEG], and functional association) were performed to analyze these data. Blood pressure measurements, tissue staining studies and RT-qPCR were performed to validate our in silico findings.

RESULTS

We discovered that empagliflozin exerted potent transcriptomic effects on various tissues, most notably the kidney, white adipose, and lung in spontaneously hypertension rats (SHR). The functional enrichment of DEGs indicated that empagliflozin may regulate blood pressure, blood glucose and lipid homeostasis in SHR. Consistent with our RNA-Seq findings, immunohistochemistry and qPCR analyses revealed decreased renal expression of mitogen-activated protein kinase 10 (MAPK10) and decreased pulmonary expression of the proinflammatory factors Legumain and cathepsin S (CTSS) at 1 month of empagliflozin administration. Notably, immunofluorescence experiments showed increased expression of the AMP-activated protein kinases Prkaa1 and Prkaa2 in white adipose tissue of SHR following empagliflozin therapy. Furthermore, the transcriptomic signatures of the blood pressure-lowing effect by empagliflozin were experimentally validated in SHR.

CONCLUSIONS

This study provided an important resource of the effects of empagliflozin on various tissues of SHRs. We identified tissue-specific and tissue-enriched transcriptomic signatures, and uncovered the beneficial effects of empagliflozin on hypertension, weight gain and inflammatory response in validated experiments.

UCP1 activation: Hottest target in the thermogenesis pathway to treat obesity using molecules of synthetic and natural origin

Uncoupling protein 1 (UCP1) has been discovered as a possible target for obesity treatment because of its widespread distribution in the inner mitochondrial membrane of brown adipose tissue (BAT) and high energy expenditure capabilities to burn calories as heat. UCP1 is dormant and does not produce heat without activation as it is inhibited by purine nucleotides. However, activation of UCP1 via either direct interaction with the UCP1 protein, an increase in the expression of UCP1 genes or the physiological production of fatty acids can lead to a rise in the thermogenesis phenomenon. Hence, activation of UCP1 through small molecules of synthetic and natural origin can be considered as a promising strategy to mitigate obesity.

Aurantio-obtusin ameliorates obesity by activating PPARα-dependent mitochondrial thermogenesis in brown adipose tissues

Obesity contributes to the progression of various chronic diseases, and shortens life expectancy. With abundant mitochondria, brown adipose tissue (BAT) dissipates energy through heat to limit weight gain and metabolic dysfunction in obesity. Our previous studies have shown that aurantio-obtusin (AO), a bioactive ingredient in Chinese traditional medicine Cassiae semen significantly improves hepatic lipid metabolism in a steatotic mouse model. In the current study we investigated the effects of AO on lipid metabolism in the BAT of diet-induced obesity mice and in oleic acid and palmitic acid (OAPA)-stimulated primary mature BAT adipocytes. Obese mice were established by feeding a HFHS diet for 4 weeks, and then administered AO (10 mg/kg, i.g.) for another 4 weeks. We showed that AO administration significantly increased the weight of BAT and accelerated energy expenditure to protect the weight increase in the obese mice. Using RNA sequencing and molecular biology analysis we found that AO significantly enhanced mitochondrial metabolism and UCP1 expression by activating PPARα both in vivo and in vitro in the primary BAT adipocytes. Interestingly, AO administration did not improve metabolic dysfunction in the liver and white adipose tissue of obese mice after interscapular BAT excision. We demonstrated that low temperature, a trigger of BAT thermogenesis, was not a decisive factor for AO to stimulate the growth and activation of BATs. This study uncovers a regulatory network of AO in activating BAT-dependent lipid consumption and brings up a new avenue for the pharmaceutical intervention in obesity and related comorbidities.

Anti-Obesity Effect and Mechanism of Chitooligosaccharides Were Revealed Based on Lipidomics in Diet-Induced Obese Mice

Chitooligosaccharide (COS) is a natural product from the ocean, and while many studies have reported its important role in metabolic diseases, no study has systematically elaborated the anti-obesity effect and mechanism of COS. Herein, COSM (MW ≤ 3000 Da) was administered to diet-induced obese mice by oral gavage once daily for eight weeks. The results show that COSM administration reduced body weight; slowed weight gain; reduced serum Glu, insulin, NEFA, TC, TG, and LDL-C levels; increased serum HSL and HDL-C levels; improved inflammation; and reduced lipid droplet size in adipose tissue. Further lipidomic analysis of adipose tissue revealed that 31 lipid species are considered to be underlying lipid biomarkers in COS therapy. These lipids are mainly enriched in pathways involving insulin resistance, thermogenesis, cholesterol metabolism, glyceride metabolism and cyclic adenosine monophosphate (cAMP), which sheds light on the weight loss mechanism of COS. The Western blot assay demonstrated that COSM intervention can improve insulin resistance, inhibit de novo synthesis, and promote thermogenesis and β-oxidation in mitochondria by the AMPK pathway, thereby alleviating high-fat diet-induced obesity. In short, our study can provide a more comprehensive direction for the application of COS in obesity based on molecular markers.

Berberine Reduces Lipid Accumulation in Obesity via Mediating Transcriptional Function of PPARδ

Obesity is defined as a dampness-heat syndrome in traditional Chinese medicine. Coptidis Rhizoma is an herb used to clear heat and eliminate dampness in obesity and its complications. Berberine (BBR), the main active compound in Coptidis Rhizoma, shows anti-obesity effects. Peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptor proteins that regulate the expression of genes involved in energy metabolism, lipid metabolism, inflammation, and adipogenesis. However, whether PPARs are involved in the anti-obesity effect of BBR remains unclear. As such, the aim of this study was to elucidate the role of PPARs in BBR treatment on obesity and the underlying molecular mechanisms. Our data showed that BBR produced a dose-dependent regulation of the levels of PPARγ and PPARδ but not PPARα. The results of gene silencing and specific antagonist treatment demonstrated that PPARδ is key to the effect of BBR. In 3T3L1 preadipocytes, BBR reduced lipid accumulation; in high-fat-diet (HFD)-induced obese mice, BBR reduced weight gain and white adipose tissue mass and corrected the disturbed biochemical parameters, including lipid levels and inflammatory and oxidative markers. Both the in vitro and in vivo efficacies of BBR were reversed by the presence of a specific antagonist of PPARδ. The results of a mechanistic study revealed that BBR could activate PPARδ in both 3T3L1 cells and HFD mice, as evidenced by the significant upregulation of PPARδ endogenous downstream genes. After activating by BBR, the transcriptional functions of PPARδ were invoked, exhibiting negative regulation of CCAAT/enhancer-binding protein α (Cebpα) and Pparγ promoters and positive mediation of heme oxygenase-1 (Ho-1) promoter. In summary, this is the first report of a novel anti-obesity mechanism of BBR, which was achieved through the PPARδ-dependent reduction in lipid accumulation.

Berberine suppressed sarcopenia insulin resistance through SIRT1-mediated mitophagy

Abnormal mitochondrial function resulting in inadequate energy supply leads to sarcopenia and IR, suggesting that maintaining mitochondrial homeostasis by regulating mitophagy may be a promising strategy for sarcopenia IR therapy. Herein, we constructed sarcopenia mice model, which was treated with berberine and/or SIRT1/mitophagy inhibitors, and the activity of SIRT1/mitophagy signaling pathway was identified. Then, muscle tissue, blood biochemical index, inflammatory factors, GTT, and ITT were detected. We found that berberine treatment increased the body weight and alleviated d-galactose-induced weight loss in mice. SIRT1/mitophagy inhibitors suppressed the effects of berberine in the treatment of sarcopenia. The effect of berberine on the increase of muscle tissue, improving metabolic disorders, reducing the expression of inflammatory factors, and suppressing sarcopenia insulin resistance (IR) were reversed by SIRT1/mitophagy inhibitors. Our study establishes proof-of-concept to distinct the effect of berberine in sarcopenia IR, and provides strong evidence to support the hypothesis that berberine-induced SIRT1 triggers mitochondrial autophagy pathway and suppresses IR in sarcopenia.

Acteoside improves adipocyte browning by CDK6-mediated mTORC1-TFEB pathway

Adipocyte browning increases energy expenditure by thermogenesis, which has been considered a potential strategy against obesity and its related metabolic diseases. Phytochemicals derived from natural products with the ability to improve adipocyte thermogenesis have aroused extensive attention. Acteoside (Act), a phenylethanoid glycoside, exists in various medicinal or edible plants and has been shown to regulate metabolic disorders. Here, the browning effect of Act was evaluated by stimulating beige cell differentiation from the stromal vascular fraction (SVF) in the inguinal white adipose tissue (iWAT) and 3 T3-L1 preadipocytes, and by converting the iWAT-SVF derived mature white adipocytes. Act improves adipocyte browning by differentiation of the stem/progenitors into beige cells and by direct conversion of mature white adipocytes into beige cells. Mechanistically, Act inhibited CDK6 and mTOR, and consequently relieved phosphorylation of the transcription factor EB (TFEB) and increased its nuclear retention, leading to induction of PGC-1α, a driver of mitochondrial biogenesis, and UCP1-dependent browning. These data thus unveil a CDK6-mTORC1-TFEB pathway that regulates Act-induced adipocyte browning.

Natural products as novel anti-obesity agents: insights into mechanisms of action and potential for therapeutic management

Obesity affects more than 10% of the adult population globally. Despite the introduction of diverse medications aimed at combating fat accumulation and obesity, a significant number of these pharmaceutical interventions are linked to substantial occurrences of severe adverse events, occasionally leading to their withdrawal from the market. Natural products serve as attractive sources for anti-obesity agents as many of them can alter the host metabolic processes and maintain glucose homeostasis via metabolic and thermogenic stimulation, appetite regulation, pancreatic lipase and amylase inhibition, insulin sensitivity enhancing, adipogenesis inhibition and adipocyte apoptosis induction. In this review, we shed light on the biological processes that control energy balance and thermogenesis as well as metabolic pathways in white adipose tissue browning, we also highlight the anti-obesity potential of natural products with their mechanism of action. Based on previous findings, the crucial proteins and molecular pathways involved in adipose tissue browning and lipolysis induction are uncoupling protein-1, PR domain containing 16, and peroxisome proliferator-activated receptor-γ in addition to Sirtuin-1 and AMP-activated protein kinase pathway. Given that some phytochemicals can also lower proinflammatory substances like TNF-α, IL-6, and IL-1 secreted from adipose tissue and change the production of adipokines like leptin and adiponectin, which are important regulators of body weight, natural products represent a treasure trove for anti-obesity agents. In conclusion, conducting comprehensive research on natural products holds the potential to accelerate the development of an improved obesity management strategy characterized by heightened efficacy and reduced incidence of side effects.

Browning of Adipocytes: A Potential Therapeutic Approach to Obesity

The increasing prevalence of overweight and obesity suggests that current strategies based on diet, exercise, and pharmacological knowledge are not sufficient to tackle this epidemic. Obesity results from a high caloric intake and energy storage, the latter by white adipose tissue (WAT), and when neither are counterbalanced by an equally high energy expenditure. As a matter of fact, current research is focused on developing new strategies to increase energy expenditure. Against this background, brown adipose tissue (BAT), whose importance has recently been re-evaluated via the use of modern positron emission techniques (PET), is receiving a great deal of attention from research institutions worldwide, as its main function is to dissipate energy in the form of heat via a process called thermogenesis. A substantial reduction in BAT occurs during normal growth in humans and hence it is not easily exploitable. In recent years, scientific research has made great strides and investigated strategies that focus on expanding BAT and activating the existing BAT. The present review summarizes current knowledge about the various molecules that can be used to promote white-to-brown adipose tissue conversion and energy expenditure in order to assess the potential role of thermogenic nutraceuticals. This includes tools that could represent, in the future, a valid weapon against the obesity epidemic.

Acetylation of p65Lys310 by p300 in macrophages mediates anti-inflammatory property of berberine

Nuclear factor (NF)-κB plays a pivotal role in the regulation of inflammatory response in macrophages. Berberine (BBR), which is an active constituent isolated from Coptis rhizome, possesses a prominent anti-inflammatory activity. Here we show that BBR changes the global acetylation landscape in LPS-induced protein acetylation of macrophages and reduces the acetylation of NF-κB subunit p65 at site Lys310(p65^Lys310), leading to the inhibition of NF-κB translocation and transcriptional activity to suppress the expressions of inflammatory factors. BBR resists the inflammatory response in acute LPS-stimulated mice through downregulation of p65^Lys310 acetylation in peritoneal macrophages. In obese mice, BBR alleviates the metabolic disorder and inflammation with the reduced acetylation of p65^Lys310 in white adipose tissue. Furthermore, we demonstrate that BBR acts as a regulator of p65^Lys310 by inhibiting the expression of p300 in macrophages. Our findings elucidate a new molecular mechanism for the anti-inflammatory effect of BBR via the p300/p65^Lys310 axis.

Berberine Ameliorates Obesity by Inducing GDF15 Secretion by Brown Adipocytes

Berberine (BBR), which is a compound derived from the Chinese medicinal plant Coptis chinensis, promotes weight loss, but the molecular mechanisms are not well understood. Here, we show that BBR increases the serum level of growth differentiation factor 15 (GDF15), which is a stress response cytokine that can reduce food intake and lower body weight in diet-induced obese (DIO) mice. The body weight and food intake of DIO mice were decreased after BBR treatment, and the weight change was negatively correlated with the serum GDF15 level. Further studies show that BBR induced GDF15 mRNA expression and secretion in the brown adipose tissue (BAT) of DIO mice and primary mouse brown adipocytes. In addition, we found that BBR upregulates GDF15 mRNA expression and secretion by activating the integrated stress response (ISR) in primary mouse brown adipocytes. Overall, our findings show that BBR lowers body weight by inducing GDF15 secretion via the activation of the ISR in BAT.