Development of Recombinant High-Density Lipoprotein Platform with Innate Adipose Tissue-Targeting Abilities for Regional Fat Reduction

As an escalating public health issue, obesity and overweight conditions are predispositions to various diseases and are exacerbated by concurrent chronic inflammation. Nonetheless, extant antiobesity pharmaceuticals (quercetin, capsaicin, catecholamine, etc.) manifest constrained efficacy alongside systemic toxic effects. Effective therapeutic approaches that selectively target adipose tissue, thereby enhancing local energy expenditure, surmounting the limitations of prevailing antiobesity modalities are highly expected. In this context, we developed a temperature-sensitive hydrogel loaded with recombinant high-density lipoprotein (rHDL) to achieve targeted delivery of resveratrol, an adipose browning activator, to adipose tissue. rHDL exhibits self-regulation on fat cell metabolism and demonstrates natural targeting toward scavenger receptor class B type I (SR-BI), which is highly expressed by fat cells, thereby achieving a synergistic effect for the treatment of obesity. Additionally, the dispersion of rHDL@Res in temperature-sensitive hydrogels, coupled with the regulation of their degradation and drug release rate, facilitated sustainable drug release at local adipose tissues over an extended period. Following 24 days' treatment regimen, obese mice exhibited improved metabolic status, resulting in a reduction of 68.2% of their inguinal white adipose tissue (ingWAT). Specifically, rHDL@Res/gel facilitated the conversion of fatty acids to phospholipids (PA, PC), expediting fat mobilization, mitigating triglyceride accumulation, and therefore facilitating adipose tissue reduction. Furthermore, rHDL@Res/gel demonstrated efficacy in attenuating obesity-induced inflammation and fostering angiogenesis in ingWAT. Collectively, this engineered local fat reduction platform demonstrated heightened effectiveness and safety through simultaneously targeting adipocytes, promoting WAT browning, regulating lipid metabolism, and controlling inflammation, showing promise for adipose-targeted therapy.

Research on the mechanism of regulating spleen-deficient obesity in rats by bawei guben huashi jiangzhi decoction based on multi-omics analysis

ETHNOPHARMACOLOGY RELEVANCE

Bawei Guben Huashi Jiangzhi Decoction (BGHJ), a traditional Chinese compound formula, comprises eight Chinese medicinal herbs: Codonopsis Radix, Atractylodis Macrocephalae Rhizoma, Cassiae Semen, Lysimachiae Herba, Edgeworthiae Gardner Flos, Oryzae Semen cum Monasco, Nelumbinis Folium, and Alismatis Rhizoma. It has the therapeutic effects of improving digestive and absorptive functions of the gastrointestinal tract, reducing cholesterol levels, and helping to lose weight. Therefore, BGHJ is mainly used to treat spleen-deficient obesity (SDO) clinically.

AIM OF THE STUDY

This study aims to examine the efficacy and mechanism of BGHJ in a model of SDO in rats, as well as the potentially involved constituents entering the blood and differential metabolites.

METHODS

The SDO rat model was replicated utilizing a high-fat and high-sugar diet in conjunction with exhaustive swimming. Subsequently, the rats were subjected to a six-week intervention comprising varying dosages of BGHJ and a positive control, orlistat. To evaluate the efficacy of BGHJ on SDO model rats, we first measured the rats' body weight, body surface temperature, spleen index, as well as biochemical indicators in the serum and colon, and then assessed the pathological state of the colon and liver. Afterward, we analyzed the 16S rDNA gut microbiota, non-targeted serum metabolomics, and serum pharmacology to study the main active components of BGHJ and its action mechanism against SDO model rats. In addition, we constructed a network diagram for overall visualization and analysis, and experimentally verified the predicted results. Finally, we used quantitative polymerase chain reaction (qPCR) to detect the gene expression of proopiomelanocortin (POMC) and neuropeptide Y (NPY) indicators in rat hypothalamic neurons. We quantitatively targeted the detection of neurotransmitters dopamine (DA), acetylcholine (Ach), 5-hydroxytryptamine (5-HT), and noradrenaline (NA) in rat hypothalamus.

RESULTS

The results demonstrated that all dosage regimens of BGHJ exhibited the capacity to moderately modulate parameters including body weight, surface temperature, spleen index, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), 5-HT, interleukin 6 (IL-6) and interleukin 17 (IL-17), while concurrently reducing hepatic lipid droplet deposition and restoring intestinal integrity. Subsequent experimental results showed that we successfully identified 27 blood components of BGHJ and identified 52 differential metabolites in SDO model rats. At the same time, the experiment proved that BGHJ could effectively inhibit the metabolic pathway of arachidonic acid. In addition, BGHJ can also restore the intestinal microbiota composition of SDO model rats. Finally, we also found that BGHJ could regulate the expression of hypothalamic neurons and neurotransmitters.

CONCLUSIONS

The research revealed the main active ingredients of BGHJ and its mechanism against SDO model rats through gut microbiota, non-target serum metabolomics, and serum drug chemistry.

Underlying mechanisms behind the neuroprotective effect of vanillic acid against diabetes-associated cognitive decline: An in vivo study in a rat model

Hippocampal synaptic dysfunction, oxidative stress, neuroinflammation, and neuronal loss play critical roles in the pathophysiology of diabetes-associated cognitive decline (DACD). The study aimed to investigate the effects of vanillic acid (VA), a phenolic compound, against DACD and explore the potential underlying mechanisms. Following confirmation of diabetes, rats were treated with VA (50 mg/kg/day; P.O.) or insulin (6 IU/rat/day; S.C.) for 8 consecutive weeks. The cognitive performance of the rats was evaluated using passive-avoidance and water-maze tasks. Long-term potentiation (LTP) was induced at hippocampal dentate gyrus (DG) synapses in response to high-frequency stimulation (HFS) applied to the perforant pathway (PP) to evaluate synaptic plasticity. Oxidative stress factors, inflammatory markers, and histological changes were evaluated in the rat hippocampus. This study showed that streptozotocin (STZ)-induced diabetes caused cognitive decline that was associated with inhibition of LTP induction, suppression of enzymatic antioxidant activities, enhanced lipid peroxidation, elevated levels of inflammatory proteins, and neuronal loss. Interestingly, chronic treatment with VA alleviated blood glucose levels, improved cognitive decline, ameliorated LTP impairment, modulated oxidative-antioxidative status, inhibited inflammatory response, and prevented neuronal loss in diabetic rats at a level comparable to insulin therapy. The results suggest that the antihyperglycemic, antioxidative, anti-inflammatory, and neuroplastic properties of VA may be the mechanisms behind its neuroprotective effect against DACD.

Valorization of grape (Vitis vinifera) leaves for bioactive compounds: novel green extraction technologies and food-pharma applications

Grape leaves, scientifically known as Vitis vinifera, the primary by-product obtained after the processing of grapes, are gathered in enormous amounts and disposed of as agricultural waste. For more sustainable agriculture and better food systems, it is crucial to investigate these byproducts' nutritional values. The primary bioactive compounds present in grape leaves are quercetin, resveratrol, caffeic acid, kaempferol, and gallic acid, which favour pharmacological effects on human health such as antioxidant, anti-inflammatory, anti-obesity, anti-diabetic, and hepatoprotective. Furthermore, grape leaves extract has been used as a functional ingredient for creating both food and non-food products. The aim of the current review is to review the nutritional and phytochemical composition of various varieties of grape leaves, their health-promoting characteristics and their applications. The study also highlights the various extraction techniques including conventional and non-conventional methods for extracting the various bioactive compounds present in grape leaves. Grape leaves bioactives can be extracted using environmentally safe and sustainable processes, which are in line with the rising demand for eco-friendly and healthful products worldwide. These methods are perfectly suited to the changing needs of both customers and industries since they lessen environmental effect, enhance product quality, and offer financial advantages.

Natural products in non-alcoholic fatty liver disease (NAFLD): Novel lead discovery for drug development

With changing lifestyles, non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide. A substantial increase in the incidence, mortality, and associated burden of NAFLD-related advanced liver disease is expected. Currently, the initial diagnosis of NAFLD is still based on ultrasound and there is no approved treatment method. Lipid-lowering drugs, vitamin supplementation, and lifestyle improvement treatments are commonly used in clinical practice. However, most lipid-lowering drugs can produce poor patient compliance and specific adverse effects. Therefore, the exploration of bio-diagnostic markers and active lead compounds for the development of innovative drugs is urgently needed. More and more studies have reported the anti-NAFLD effects and mechanisms of natural products (NPs), which have become an important source for new drug development to treat NAFLD due to their high activity and low side effects. At present, berberine and silymarin have been approved by the US FDA to enter clinical phase IV studies, demonstrating the potential of NPs against NAFLD. Studies have found that the regulation of lipid metabolism, insulin resistance, oxidative stress, and inflammation-related pathways may play important roles in the process. With the continuous updating of technical means and scientific theories, in-depth research on the targets and mechanisms of NPs against NAFLD can provide new possibilities to find bio-diagnostic markers and innovative drugs. As we know, FXR agonists, PPARα agonists, and dual CCR2/5 inhibitors are gradually coming on stage for the treatment of NAFLD. Whether NPs can exert anti-NAFLD effects by regulating these targets or some unknown targets remains to be further studied. Therefore, the study reviewed the potential anti-NAFLD NPs and their targets. Some works on the discovery of new targets and the docking of active lead compounds were also discussed. It is hoped that this review can provide some reference values for the development of non-invasive diagnostic markers and new drugs against NAFLD in the clinic.

Ameliorative Effects of Anthocyanin Metabolites on Western Diet-Induced NAFLD by Modulating Co-Occurrence Networks of Gut Microbiome

Anthocyanins (Acn) have been reported to have preventive effects on Western diet (WD)-induced non-alcoholic fatty liver disease (NAFLD). However, the amount of Acn that reached the bloodstream were less than 1%, suggesting that anthocyanin metabolites (Acn-M) in the gut may contribute to their in vivo effects. This study is focused on a gut microbiota investigation to elucidate the effect of two major Acn-M, protocatechuic acid (PC) and phloroglucinol carboxaldehyde (PG), on NAFLD prevention. C57BL/6N male mice were divided into five groups and fed with a normal diet (ND), WD, WD + 0.5% PC, WD + 0.5% PG and WD + a mixture of 0.25% PC + 0.25% PG (CG) for 12 weeks. The results revealed that WD-fed mice showed a significant increase in final body weight, epididymis fat weight, liver weight and fat accumulation rate, serum total cholesterol, alanine aminotransferase, monocyte chemoattractant protein 1, and 2-thiobarbituric acid reactive substances. At the same time, these indices were significantly decreased by Acn-M in the order of PG, CG > PC. In particular, PG significantly decreased serum glucose and insulin resistance. Gut microbiome analysis revealed that PG significantly increased the relative abundance of Parabacteroides, Prevotella, Prevotella/Bacteroides ratio, and upregulated glucose degradation pathway. Interestingly, the co-occurrence networks of Lachnospiraceae and Desulfovibrionaceae in the PC and PG groups were similar to the ND group and different to WD group. These data suggest that PC and PG were able to recover the gut microbiome networks and functions from dysbiosis caused by WD. Therefore, PG might act as a master metabolite for anthocyanins and prevent WD-induced NAFLD and gut dysbiosis.

Mitochondria-associated regulation in adipose tissues and potential reagents for obesity intervention

Introduction

A systematic review analysis was used to assess the profile of mitochondrial involvement in adipose tissue regulation and potential reagents to intervene in obesity through the mitochondrial pathway.

Methods

Three databases, PubMed, Web of Science, and Embase, were searched online for literature associated with mitochondria, obesity, white adipose tissue, and brown adipose tissue published from the time of their creation until June 22, 2022, and each paper was screened.

Results

568 papers were identified, of which 134 papers met the initial selection criteria, 76 were selected after full-text review, and 6 were identified after additional searches. A full-text review of the included 82 papers was performed.

Conclusion

Mitochondria play a key role in adipose tissue metabolism and energy homeostasis, including as potential therapeutic agents for obesity.

PPARG: A Promising Therapeutic Target in Breast Cancer and Regulation by Natural Drugs

Breast cancer (BC) is the most common type of cancer among females. Peroxisome proliferator-activated receptor gamma (PPARG) can regulate the production of adipocyte-related genes and has anti-inflammatory and anti-tumor effects. Our aim was to investigate PPARG expression, its possible prognostic value, and its effect on immune cell infiltration in BC, and explore the regulatory effects of natural drugs on PPARG to find new ways to treat BC. Using different bioinformatics tools, we extracted and comprehensively analyzed the data from the Cancer Genome Atlas, Genotype-Tissue Expression, and BenCaoZuJian databases to study the potential anti-BC mechanism of PPARG and potential natural drugs targeting it. First, we found that PPARG was downregulated in BC and its expression level correlates with pathological tumor stage (pT-stage) and pathological tumor-node-metastasis stage (pTNM-stage) in BC. PPARG expression was higher in estrogen receptor-positive (ER+) BC than in estrogen receptor-negative (ER-) BC, which tends to indicate a better prognosis. Meanwhile, PPARG exhibited a significant positive correlation with the infiltration of immune cells and correlated with better cumulative survival in BC patients. In addition, PPARG levels were shown to be positively associated with the expression of immune-related genes and immune checkpoints, and ER+ patients had better responses to immune checkpoint blocking. Correlation pathway research revealed that PPARG is strongly associated with pathways, such as angiogenesis, apoptosis, fatty acid biosynthesis, and degradation in ER+ BC. We also found that quercetin is the most promising natural anti-BC drug among natural medicines that upregulate PPARG. Our research showed that PPARG may reduce BC development by regulating the immune microenvironment. Quercetin as PPARG ligands/agonists is a potential natural drug for BC treatment.

Attenuation of Oxidative Stress and Regulation of AKT Signaling by Vanillic Acid during Bovine Pre-Implantation Embryo Development

Vanillic acid (VA) has shown antioxidant and anti-inflammatory activities in different cell types, but its biological effects in the context of early embryo development have not yet been clarified. In the current study, the impact of VA supplementation during in vitro maturation (IVM) and/or post-fertilization (in vitro culture; IVC) on redox homeostasis, mitochondrial function, AKT signaling, developmental competence, and the quality of bovine pre-implantation embryos was investigated. The results showed that dual exposure to VA during IVM and late embryo culture (IVC3) significantly improved the blastocyst development rate, reduced oxidative stress, and promoted fatty acid oxidation as well as mitochondrial activity. Additionally, the total numbers of cells and trophectoderm cells per blastocyst were higher in the VA-treated group compared to control (p < 0.05). The RT-qPCR results showed down-regulation of the mRNA of the apoptosis-specific markers and up-regulation of AKT2 and the redox homeostasis-related gene TXN in the treated group. Additionally, the immunofluorescence analysis showed high levels of pAKT-Ser473 and the fatty acid metabolism marker CPT1A in embryos developed following VA treatment. In conclusion, the study reports, for the first time, the embryotrophic effects of VA, and the potential linkage to AKT signaling pathway that could be used as an efficacious protocol in assisted reproductive technologies (ART) to improve human fertility.

Black rice regulates lipid metabolism, liver injury, oxidative stress and adipose accumulation in high-fat/cholesterol diet mice based on gut microbiota and untargeted metabonomics

Black rice displays a series of properties including regulating lipid metabolism and attenuating liver injury. Our study aimed to investigate the effect of Zixiangnuo black rice (ZG), peeled rice (ZPG), rice bran (ZBG) on lipid metabolism, liver inflammation, gut microbiota and metabolite profiles in high-fat/cholesterol (HFCD) diet mice. A total of 5 treatment groups were fed a normal control diet or a HFCD with or without HB supplementation for 10 weeks. The results showed that ZBG significantly improved lipid parameters, liver function and injury and blood glucose indexes related to hyperlipidemia compared with HFCD group. ZBG recovered the disorder of gut microbiota by increasing Bacteroidetes/Firmicutes ratio and Lactobacillus abundance, and decreasing Proteobacteria abundance. ZBG enhanced the levels of 6 short chain fatty acids. Fecal metabolomics analysis showed that the important differential metabolites between ZBG and HFCD group were Deoxycholic acid and Myclobutanil, and metabolic pathways were Arachidonic acid metabolism and ABC transporters. Results suggested that BR or bran were effective dietary candidates to ameliorate hyperlipidemia.

Bioactive Compounds (BACs): A Novel Approach to Treat and Prevent Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the leading disorders of serious death and cause huge economic loss to patients and society. It is estimated that about 18 million people have a high death ratio due to the incidence of CVDs such as (stroke, coronary heart disease, and non-ischemic heart failure). Bioactive compounds (BACs) are healthy nutritional ingredients providing beneficial effects and nutritional value to the human body. Epidemiological studies strongly shed light on several bioactive compounds that are favorable candidates for CVDs treatment. Globally, the high risk of CVDs and related results on human body parts made them a serious scenario in all communities. In this present review, we intend to collect previously published data concerned over the years concerning green-colored foods and their BACs that aim to work in the prevention, diagnosis, and/or systematic treating CVDs. We also comprehensively discussed the oral delivery of several bioactive compounds derived from fruits and vegetables and their bioavailability and physiological effects on human health. Moreover, their important characteristics, such as anti-inflammatory, lowering blood pressure, anti-obesity, antioxidant, anti-diabetics, lipid-lowering responses, improving atherosclerosis, and cardioprotective properties, will be elaborated further. More precisely, medicinal plants' advantages and multifaceted applications have been reported in this literature to treat CVDs. To the best of our knowledge, this is our first attempt that will open a new window in the area of CVDs with the opportunity to achieve a better prognosis and effective treatment for CVDs.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Targeting mTOR Signaling by Dietary Polyphenols in Obesity Prevention

Dietary polyphenols can be utilized to treat obesity and chronic disorders linked to it. Dietary polyphenols can inhibit pre-adipocyte proliferation, adipocyte differentiation, and triglyceride accumulation; meanwhile, polyphenols can also stimulate lipolysis and fatty acid β-oxidation, but the molecular mechanisms of anti-obesity are still unclear. The mechanistic target of rapamycin (mTOR) is a protein kinase that regulates cell growth, survival, metabolism, and immunity. mTOR signaling is also thought to play a key role in the development of metabolic diseases such as obesity. Recent studies showed that dietary polyphenols could target mTOR to reduce obesity. In this review, we systematically summarized the research progress of polyphenols in preventing obesity through the mTOR signaling pathway. Mechanistically, polyphenols can target multiple signaling pathways and gut microbiota to regulate the mTOR signaling pathway to exert anti-obesity effects. The main mechanisms include: modulating lipid metabolism, adipogenesis, inflammation, etc. Dietary polyphenols exerting an anti-obesity effect by targeting mTOR signaling will broaden our understanding of the anti-obesity mechanisms of polyphenols and provide valuable insights for researchers in this novel field.

Immune-Enhancing Effect of Sargassum horneri on Cyclophosphamide-Induced Immunosuppression in BALB/c Mice and Primary Cultured Splenocytes

Sargassum horneri (SH) is a seaweed that has several features that benefit health. In this study, we investigated the immune-enhancing effect of SH, focusing on the role of spleen-mediated immune functions. Chromatographic analysis of SH identified six types of monosaccharide contents, including mannose, rhamnose glucose, galactose xylose and fucose. SH increased cell proliferation of primary cultured naïve splenocytes treated with or without cyclophosphamide (CPA), an immunosuppression agent. SH also reversed the CPA-induced decrease in Th1 cytokines. In vivo investigation revealed that SH administration can increase the tissue weight of major immune organs, such as the spleen and thymus. A similar effect was observed in CPA-injected immunosuppressed BALB/c mice. SH treatment increased the weight of the spleen and thymus, blood immune cell count and Th1 cytokine expression. Additionally, the YAC-1-targeting activities of natural killer cells, which are important in innate immunity, were upregulated upon SH treatment. Overall, our study demonstrates the immune-enhancing effect of SH, suggesting its potential as a medicinal or therapeutic agent for pathologic conditions involving immunosuppression.

Potential of Natural Honey in Controlling Obesity and its Related Complications

Honey has a long history of therapeutic properties for multiple diseases, including inflammation and oxidative stress. This review aimed to provide a better understanding and renewed interest in the potential role of honey in obesity control, obesity-related diseases treatment and weight management, with specific reference to its components and the effect of honey overall. There is compelling evidence that honey possesses the desired properties for this purpose, as seen in the in vitro, in silico, in vivo and clinical analyses discussed in this review. This review also highlights the components potentially responsible for the health benefits of honey. Honey and its components reduce blood sugar levels, improve insulin sensitivity and lipid metabolism by reducing triglycerides, and reduce total cholesterol and LDL levels while increasing HDL levels that prevent excessive weight gain and reduce the risk of obesity and its complications. Further controlled studies are necessary to validate the role of honey in the management of obesity, both as a preventive and as a therapeutic agent.

Grape Polyphenols in the Treatment of Human Skeletal Muscle Damage Due to Inflammation and Oxidative Stress during Obesity and Aging: Early Outcomes and Promises

Today, inactivity and high-calorie diets contribute to the development of obesity and premature aging. In addition, the population of elderly people is growing due to improvements in healthcare management. Obesity and aging are together key risk factors for non-communicable diseases associated with several co-morbidities and increased mortality, with a major impact on skeletal muscle defect and/or poor muscle mass quality. Skeletal muscles contribute to multiple body functions and play a vital role throughout the day, in all our activities. In our society, limiting skeletal muscle deterioration, frailty and dependence is not only a major public health challenge but also a major socio-economic issue. Specific diet supplementation with natural chemical compounds such as grape polyphenols had shown to play a relevant and direct role in regulating metabolic and molecular pathways involved in the prevention and treatment of obesity and aging and their related muscle comorbidities in cell culture and animal studies. However, clinical studies aiming to restore skeletal muscle mass and function with nutritional grape polyphenols supplementation are still very scarce. There is an urgent need for clinical studies to validate the very encouraging results observed in animal models.

Obesity induces adipose fibrosis and collagen cross-linking through suppressing AMPK and enhancing lysyl oxidase expression

Collagen is the main component of connective tissue surrounding adipocytes. Collagen cross-linking affects adipose remodeling, which is crucial for maintaining function and metabolic homeostasis of adipose tissue. However, the effects of obesity on collagen cross-linking and adipose fibrosis remain to be examined. Therefore, the objective of this study was to investigate obesity-induced collagen cross-linking in adipose tissue and explore the underlying mechanisms. We found that obesity increased mature nonreducible collagen cross-linking in white adipose tissue (WAT) of mice, which was associated with inhibition of AMPK, up-regulation of transforming growth factor-β (TGF-β) signaling and the expression of lysyl oxidase (LOX), a key enzyme catalyzing the synthesis of mature cross-linking products. In SVCs and 3T3-L1 adipocytes, AMPK activation by metformin or AICAR inhibited TGF-β1-induced fibrogenesis and expression of LOX, which was further confirmed by ectopic expression of AMPK WT and K45R mutant. Consistently, in vivo, knocking out AMPK increased fibrosis and collagen cross-linking. Our study showed that AMPK downregulation due to obesity increases TGF-β signaling and LOX expression, which enhances adipose fibrosis and collagen cross-linking. Thus, AMPK is a therapeutic target for ameliorating the obesity-induced fibrosis, improving metabolic health of adipose tissue.

Role of Bioactive Compounds in Obesity: Metabolic Mechanism Focused on Inflammation

Obesity is a disease characterized by an inflammatory process in the adipose tissue due to diverse infiltrated immune cells, an increased secretion of proinflammatory molecules, and a decreased secretion of anti-inflammatory molecules. On the other hand, obesity increases the risk of several diseases, such as cardiovascular diseases, diabetes, and cancer. Their treatment is based on nutritional and pharmacological strategies. However, natural products are currently implemented as complementary and alternative medicine (CAM). Polyphenols and fiber are naturally compounds with potential action to reduce inflammation through several pathways and play an important role in the prevention and treatment of obesity, as well as in other non-communicable diseases. Hence, this review focuses on the recent evidence of the molecular mechanisms of polyphenols and dietary fiber, from Scopus, Science Direct, and PubMed, among others, by using key words and based on recent in vitro and in vivo studies.

Physiological Effects of Green-Colored Food-Derived Bioactive Compounds on Cardiovascular and Metabolic Diseases

Cardiovascular and metabolic diseases are a leading cause of death worldwide. Epidemiological studies strongly highlight various benefits of consuming colorful fruits and vegetables in everyday life. In this review, we aimed to revisit previous studies conducted in the last few decades regarding green-colored foods and their bioactive compounds in consideration of treating and/or preventing cardiovascular and metabolic diseases. This review draws a comprehensive summary and assessment of research on the physiological effects of various bioactive compounds, mainly polyphenols, derived from green-colored fruits and vegetables. In particular, their health-beneficial effects, including antioxidant, anti-inflammatory, anti-diabetic, anti-obesity, cardioprotective, and lipid-lowering properties, will be discussed. Furthermore, the bioavailability and significance of action of these bioactive compounds on cardiovascular and metabolic diseases will be discussed in detail.

Raphani Semen (Raphanus sativus L.) Ameliorates Alcoholic Fatty Liver Disease by Regulating De Novo Lipogenesis

In this study, we investigated the pharmacological effect of a water extract of Raphani Semen (RSWE) on alcoholic fatty liver disease (AFLD) using ethanol-induced AFLD mice (the NIAAA model) and palmitic acid (PA)-induced steatosis HepG2 cells. An RSWE supplement improved serum and hepatic triglyceride (TG) levels of AFLD mice, as well as their liver histological structure. To explore the molecular action of RSWE in the improvement of AFLD, we investigated the effect of RSWE on four major pathways for lipid homeostasis in the liver: free fatty acid transport, lipogenesis, lipolysis, and β-oxidation. Importantly, RSWE decreased the mRNA expression of de novo lipogenesis-related genes, such as Srebf1, Cebpa, Pparg, and Lpin1, as well as the protein levels of these factors, in the liver of AFLD mice. That these actions of RSWE affect lipogenesis was confirmed using PA-induced steatosis HepG2 cells. Overall, our findings suggest that RSWE has the potential for improvement of AFLD by inhibiting de novo lipogenesis.

Potential Health Benefits of Whole Grains: Modulation of Mitochondrial Biogenesis and Energy Metabolism

Mitochondria play an essential role in maintaining cellular metabolic homeostasis. However, its dysfunction will cause different pathophysiological consequences. A specific mechanism of action has been developed by cells to adapt to changes in physiological conditions or in response to different stimuli, by meditating mitochondrial number, structure, and energy metabolism. Whole grains are considered healthier than refined grains for their higher amounts of bioactive components, with proven multiple health benefits. The modulation of an appropriate mitochondrial function contributes to the bioactive-component-based health improvements. Thus, this review aims to represent current studies that identify the impact of natural bioactive components in whole grains against metabolic disorders by modulating mitochondrial biogenesis and energy metabolism. It seems most attractive to aim nutritional intervention at the prevention or treatment of metabolic abnormalities and hence to target dietary management at improvement of mitochondrial function.

Effect of vanillic acid and exercise training on fatty liver and insulin resistance in rats: Possible role of fibroblast growth factor 21 and autophagy

BACKGROUND AND AIMS

The prevalence of non-alcoholic fatty liver disease has been alarmingly increased with no lines of effective treatment. Vanillic acid is a naturally occurring polyphenol with promising therapeutic effects. Exercise is well known to be an effective tool against obesity and its consequences. Thus, we aim to study the effect of vanillic acid alone and along with exercise on fatty liver induced by a high-fat diet in a rat model and to investigate possible novel mechanisms involved in their action.

METHODS

In this study, 40 male rats were divided equally into five groups: control (standard chow diet), HFD (high-fat diet), HFD+VA (HFD+ vanillic acid (50 mg/kg/day orally), HFD+EX (HFD+ swimming exercise 5 days/week), HFD+VA+EX (HFD+ vanillic acid+ swimming exercise) for eight weeks.

RESULTS

Body mass, liver weight, liver enzymes, cholesterol, and triglycerides were significantly decreased in the combined VA+EX group, with marked improvement in hyperglycemia, hyperinsulinemia, and consequently HOMA-IR index compared to the HFD group. These improvements were also reflected in the pathological view. VA and swimming, either solely or in combination, markedly increased hepatic and circulating fibroblast growth factor 21. Additionally, VA and swimming increased the immunohistochemical expression of the autophagosomal marker LC3 and decreased the expression of P62, which is selectively degraded during autophagy.

CONCLUSIONS

These results suggest the hepatoprotective effect of VA and swimming exercise against fatty liver and the involvement of FGF21 and autophagy in their effect.

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.

Food phenolics stimulate adipocyte browning via regulating gut microecology

Fat browning has piqued the interest of researchers as a potential target for treating obesity and related metabolic disorders. Recruitment of brown adipocytes leads to enhanced energy dissipation and reduced adiposity, thus facilitating the maintenance of metabolic homeostasis. Evidence is increasing to support the crucial roles of polyphenols and gut microecology in turning fat "brown". However, it is not clear whether the intestinal microecology is involved in polyphenol-mediated regulation of adipose browning, so this concept is worthy of exploration. In this review, we summarize the current knowledge, mostly from studies with murine models, supporting the concept that the effects of food phenolics on brown fat activation and white fat browning can be attributed to their regulatory actions on gut microecology, including microbial community profile, gut metabolites, and gut-derived hormones. Furthermore, the potential underlying pathways involved are also discussed. Basically, understanding gut microecology paves the way to determine the underlying roles and mechanisms of food phenolics in adipose browning.

Microbial Flavonoid Metabolism: A Cardiometabolic Disease Perspective

Cardiometabolic disease (CMD) is a leading cause of death worldwide and encompasses the inflammatory metabolic disorders of obesity, type 2 diabetes mellitus, nonalcoholic fatty liver disease, and cardiovascular disease. Flavonoids are polyphenolic plant metabolites that are abundantly present in fruits and vegetables and have biologically relevant protective effects in a number of cardiometabolic disorders. Several epidemiological studies underscored a negative association between dietary flavonoid consumption and the propensity to develop CMD. Recent studies elucidated the contribution of the gut microbiota in metabolizing dietary intake as it relates to CMD. Importantly, the biological efficacy of flavonoids in humans and animal models alike is linked to the gut microbial community. Herein, we discuss the opportunities and challenges of leveraging flavonoid intake as a potential strategy to prevent and treat CMD in a gut microbe-dependent manner, with special emphasis on flavonoid-derived microbial metabolites.

Non-shivering Thermogenesis Signalling Regulation and Potential Therapeutic Applications of Brown Adipose Tissue

In mammals, thermogenic organs exist in the body that increase heat production and enhance energy regulation. Because brown adipose tissue (BAT) consumes energy and generates heat, increasing energy expenditure via BAT might be a potential strategy for new treatments for obesity and obesity-related diseases. Thermogenic differentiation affects normal adipose tissue generation, emphasizing the critical role that common transcriptional regulation factors might play in common characteristics and sources. An understanding of thermogenic differentiation and related factors could help in developing ways to improve obesity indirectly or directly through targeting of specific signalling pathways. Many studies have shown that the active components of various natural products promote thermogenesis through various signalling pathways. This article reviews recent major advances in this field, including those in the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA), cyclic guanosine monophosphate-GMP-dependent protein kinase G (cGMP-AKT), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), transforming growth factor-β/bone morphogenic protein (TGF-β/BMP), transient receptor potential (TRP), Wnt, nuclear factor-κ-light-chain-enhancer of activated B cells (NF-κΒ), Notch and Hedgehog (Hh) signalling pathways in brown and brown-like adipose tissue. To provide effective information for future research on weight-loss nutraceuticals or drugs, this review also highlights the natural products and their active ingredients that have been reported in recent years to affect thermogenesis and thus contribute to weight loss via the above signalling pathways.

Vanillic Acid and Non-Alcoholic Fatty Liver Disease: A Focus on AMPK in Adipose and Liver Tissues

Non-alcoholic fatty liver disease (NAFLD), a growing health issue around the world, is defined as the presence of steatosis in the liver without any other detectable byproducts such as alcohol consumption which includes a wide spectrum of pathologies, such as steatohepatitis, cirrhosis, and hepatocellular carcinoma. A growing body of evidence indicates that the reduction in the 5' adenosine monophosphate-activated protein kinase (AMPK) activity, which could be activated by the consumption of the drugs, hormones, cytokines, and dietary restriction, is related to some metabolic disorders such as obesity, diabetes, PCOS, and NAFLD. Vanillic acid (VA), as an anti-inflammatory, anti-oxidative, anti-angiogenic and anti-metastatic factor, has protective effects on the liver as in two animal models of liver damage. It reduces serum levels of transaminases, inflammatory cytokines, and the accumulation of collagen in the liver and prevents liver fibrosis. Besides, it decreases body and adipose tissue weight in a mice model of obesity and, similar to the liver tissue, diminishes adipogenesis through the activation of AMPK. It has been reported that VA can target almost all of the metabolic abnormalities of NAFLD, such as hepatic steatosis, inflammation, and hepatic injury, at least partially through the activation of AMPK. Therefore, in this review, we will discuss the possible and hypothetical roles of VA in NAFLD, with a special focus on AMPK.

Phenolic acid metabolites of polyphenols act as inductors for hormesis in C. elegans

INTRODUCTION

Aging represents a major risk factors for metabolic diseases, such as diabetes, obesity, or neurodegeneration. Polyphenols and their metabolites, especially simple phenolic acids, gained growing attention as a preventive strategy against age-related, non-communicable diseases, due to their hormetic potential. Using Caenorhabditis elegans (C. elegans) we investigate the effect of protocatechuic, gallic, and vanillic acid on mitochondrial function, health parameters, and the induction of potential hormetic pathways.

METHODS

Lifespan, heat-stress resistance and chemotaxis of C. elegans strain P X 627, a specific model for aging, were assessed in 2-day and 10-day old nematodes. Mitochondrial membrane potential (ΔΨm) and ATP generation were measured. mRNA expression levels of longevity and energy metabolism-related genes were determined using qRT-PCR.

RESULTS

All phenolic acids were able to significantly increase the nematodes lifespan, heat-stress resistance and chemotaxis at micromolar concentrations. While ΔΨm was only affected by age, vanillic acid (VA) significantly decreased ATP concentrations in aged nematodes. Longevity pathways, were activated by all phenolic acids, while VA also induced glycolytic activity and response to cold.

CONCLUSION

While life- and health span parameters are positively affected by the investigated phenolic acids, the concentrations applied were unable to affect mitochondrial performance. Therefore we suggest a hormetic mode of action, especially by activation of the sirtuin-pathway.

SCFJFK is functionally linked to obesity and metabolic syndrome

Dysregulation of lipid metabolism could lead to the development of metabolic disorders. We report here that the F-box protein JFK promotes excessive lipid accumulation in adipose tissue and contributes to the development of metabolic syndrome. JFK transgenic mice develop spontaneous obesity, accompanied by dyslipidemia, hyperglycemia, and insulin resistance, phenotypes that are further exacerbated under high-fat diets. In contrast, Jfk knockout mice are lean and resistant to diet-induced metabolic malfunctions. Liver-specific reconstitution of JFK expression in Jfk knockout mice leads to hepatic lipid accumulation resembling human hepatic steatosis and nonalcoholic fatty liver disease. We show that JFK interacts with and destabilizes ING5 through assembly of the SCF complex. Integrative transcriptomic and genomic analysis reveals that the SCF^JFK -ING5 axis interferes with AMPK activity and fatty acid β-oxidation, leading to the suppression of hepatic lipid catabolism. Significantly, JFK is upregulated and AMPKα1 is down-regulated in liver tissues from NAFLD patients. These results reveal that SCF^JFK is a bona fide E3 ligase for ING5 and link the SCF^JFK -ING5 axis to the development of obesity and metabolic syndrome.

Gomisin A Alleviates Obesity by Regulating the Phenotypic Switch between White and Brown Adipocytes

Although gomisin A (GA) alleviates cancer and inflammation, its anti-obesity effect and the underlying mechanism have not yet been elucidated. Therefore, in this study, we aimed to elucidate the anti-obesity effects of GA by investigating the phenotypic changes involved in the browning and whitening of adipocytes. Here, obesity was induced to C57BL/6J mice using a high-fat diet (HFD). We administrated GA and checked weight changes for 12 weeks. We found that GA decreased the weight of weight gain, epididymal white adipose tissue (eWAT), and liver in the mice. In addition, the administration of GA elevated the levels of high-density lipoprotein (HDL)-cholesterol in the mice serum. Moreover, even after 12 weeks of treatment with GA, it did not cause any hepatic and renal toxicity. However, we found that GA induced the browning of eWAT and inhibited the whitening of brown adipose tissue. We further confirmed the anti-obesity mechanism of GA using 3T3-L1 cells, the human adipose mesenchymal stem cells (hAMSCs), and primary brown adipocytes (BAs) in vitroexperiments. We found that GA suppressed adipogenesis via the activation of AMP-activated protein kinase (AMPK). Furthermore, GA-induced browning by increasing the expression levels of uncoupling protein 1 (UCP1) in hAMSCs. The results of our study indicate that GA can inhibit weight gain by regulating the phenotypic changes involved in the browning and whitening of adipose tissues, which makes it a potential therapeutic agent for the treatment of obesity.

Farnesol induces mitochondrial/peroxisomal biogenesis and thermogenesis by enhancing the AMPK signaling pathway in vivo and in vitro

Thermogenic activation of brown adipose tissue has been considered as an obesity treatment strategy that consumes energy. In this study, we investigated whether farnesol in vivoandin vitro models induces thermogenesis and affect the activation of the mitochondria and peroxisomes, which are key organelles in activated brown adipocytes. Farnesol induced the expression of thermogenic factors such as uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor γ coactivator 1 alpha (PGC1α), and PR domain zinc-finger protein 16 (PRDM16) together with the phosphorylation of AMP-activated protein kinase alpha (AMPKα) in brown adipose tissue and primary cultured brown adipocytes. Farnesol promoted lipolytic enzymes: hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). We confirmed that these inductions of lipolysis by farnesol were the underlying causes of β-oxidation activation. Farnesol also increased the expression of oxidative phosphorylation (OXPHOS) complexes and the oxygen consumption rate (OCR) and the expansion of peroxisomes. Moreover, we proved that the thermogenic activity of farnesol was dependent on AMPKα activation using Compound C inhibitor or siRNA-AMPKα knockdown. These results suggest that farnesol may be a potential agent for the treatment of obesity by inducing energy consumption through heat generation.

Laquinimod Prevents Adipogenesis and Obesity by Down-Regulating PPAR-γ and C/EBPα through Activating AMPK

BACKGROUND AND PURPOSE

obesity is defined as excessive accumulation of adipose tissues and is becoming one of the main global severe public health issues. The present study aims to investigate the anti-adipogenesis of laquinimod and the underlying mechanism.

METHODS

a differentiation cocktail was used to differentiate 3T3-L1 cells, and mice were fed with high fat food to establish the obesity animal model. Oil red O staining, glycerol production assay, and the release of triglyceride were used to evaluate the differentiation degree of 3T3-L1 cells. The expression level of sterol regulatory element binding transcription factor 1 (Srebp1), fatty acid binding protein-4 (FABP4), glucose transporter 4 (GLUT4), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT enhancer-binding proteins (C/EBPα), and phosphorylation of adenosine 5'-monophosphate (AMP)-activated protein kinase α (p-AMPKα) was determined by quantitative real time PCRqRT-PCR and western blot analysis. The pathological state of adipose tissues was evaluated by hematoxylin-eosin staining.

RESULTS

the amount and UV absorption of oil red O, glycerol production, release of triglyceride, and the expression of SREBP1, FABP4, and Glut4 in differentiated 3T3-L1 cells were decreased by the administration of laquinimod. PPAR-γ and C/EBPα were down-regulated, and p-AMPKα was up-regulated by laquinimod. The down-regulated PPAR-γ and C/EBPα, as well as the inhibited lipid accumulation functioned by laquinimod, were reversed by the coincubation with the AMPK inhibitor compound C. Decreased body weight, visceral adipocyte tissue weight, and size of adipocytes were observed in in vivo obesity mice after administration with laquinimod.

CONCLUSION

laquinimod might prevent adipogenesis by down-regulating PPAR-γ and C/EBPα through activating AMPK.

Stimulation of brown adipose tissue by polyphenols in extra virgin olive oil

Obesity is one of the main public health problems of the 21^st century resulting from an imbalance between calorie intake and energy expenditure. Currently, the search for new treatments against this pathology has become a priority. One of the therapeutic strategies against obesity could be the activation of brown adipose tissue through different molecules such as the phenolic compounds of extra virgin olive oil (EVOO). The objective of this review was to provide an update of scientific knowledge on the relationship between EVOO phenolic compounds and brown adipose tissue.According to this review, it has been demonstrated that extra virgin olive oil phenolic compounds can have beneficial effects on obesity by activating brown adipose tissue and enhance thermogenesis through different signaling pathways mediated by molecules such as AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator-1α (PGC1α) or sirtuin 1 (Sirt1).

Vanillic Acid Improves Comorbidity of Cancer and Obesity through STAT3 Regulation in High-Fat-Diet-Induced Obese and B16BL6 Melanoma-Injected Mice

Obesity is known to be associated with risk and aggressiveness of cancer. Melanoma, the most lethal type of skin cancer, is also closely related to the prevalence of obesity. In this study, we established a cancer–obesity comorbidity (COC) model to investigate the effects of vanillic acid (VA). After a five-week administration with a high-fat diet (HFD) to induce obesity, subcutaneous allograft of B16BL6 cells were followed, and VA was orally administrated for an additional two weeks. VA-fed mice showed significantly decreased body weight and white adipose tissue (WAT) weight, which were due to increased thermogenesis and AMPK activation in WATs. Growth of cancer was also suppressed. Mechanistic studies revealed increased apoptosis and autophagy markers by VA; however, caspase 3 was not involved. Since signal transducer and activator of transcription 3 (STAT3) is suggested as an important pathway linking obesity and cancer, we further investigated to find out if STAT3 phosphorylation was repressed by VA treatment, and this was again confirmed in a COC cell model of adipocyte conditioned medium-treated B16BL6 melanoma cells. Overall, our results show VA induces STAT3-mediated autophagy to inhibit cancer growth and thermogenesis to ameliorate obesity in COC. Based on these findings, we suggest VA as a candidate therapeutic agent for COC treatment.

Fruit of Hovenia dulcis Thunb. Induces Nonshivering Thermogenesis through Mitochondrial Biogenesis and Activation by SIRT1 in High-Fat Diet-Fed Obese Mice and Primary Cultured Brown Adipocytes

Brown adipocytes, which contain abundant mitochondria, use stored energy as fuel during a process named nonshivering thermogenesis. Thus, the pharmacological activation of thermogenesis in brown adipose tissue (BAT) has become a promising target for treating obesity. We investigated the effect of fruit of Hovenial dulcis Thunb. (FHD), a frequently used herbal treatment for liver diseases, on thermogenesis and its mechanism using primary cultured brown adipocytes and BAT of high-fat-diet (HFD)-induced obese mice. Thermogenesis-related factors including UCP1 and PGC1α increased with FHD treatment. FHD also increased mitochondrial biogenesis and activation factors such as nuclear respiratory factor (NRF)1 and oxidative phosphorylation (OXPHOS) complex. Furthermore, FHD increased the intercellular nicotinamide adenine dinucleotide (NAD⁺) level and sirtuin 1 (SIRT1) activity, which may be responsible for the activation of the thermogenic reaction. Overall, our results suggest that FHD can be a novel option for obesity treatment due to its thermogenic action through mitochondrial biogenesis and activation.

A phytoestrogen secoisolariciresinol diglucoside induces browning of white adipose tissue and activates non-shivering thermogenesis through AMPK pathway

Secoisolariciresinol diglucoside (SDG) is the main phytoestrogen component of flaxseed known as an antioxidant. Current study focused on the effect of SDG in white adipose tissue (WAT) browning. Browning of WAT is considered as a promising treatment strategy for metabolic diseases. To demonstrate the effect of SDG as an inducer of browning, brown adipocyte markers were investigated in inguinal WAT (iWAT) of high fat diet-fed obese mice and genetically obese db/db mice after SDG administration. SDG increased thermogenic factors such as uncoupling protein 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha and PR domain containing 16 in iWAT and brown adipose tissue (BAT) of mice. Similar results were shown in beige-induced 3T3-L1 adipocytes and primary cultured brown adipocytes. Furthermore, SDG increased factors of mitochondrial biogenesis and activation. We also observed SDG-induced alteration of AMP-activated protein kinase α (AMPKα). As AMPKα is closely related in the regulation of adipogenesis and thermogenesis, we then evaluated the effect of SDG in AMPKα-inhibited conditions. Genetic or chemical inhibition of AMPKα demonstrated that the role of SDG on browning and thermogenesis was dependent on AMPKα signaling. In conclusion, our data suggest SDG as a potential candidate for improvement of obesity and other metabolic disorders.

Adiponectin homolog osmotin, a potential anti-obesity compound, suppresses abdominal fat accumulation in C57BL/6 mice on high-fat diet and in 3T3-L1 adipocytes

OBJECTIVES

Obesity is characterized by excessive fat accumulation due to an imbalance between energy intake and expenditure. Osmotin, a plant derived natural protein, is a known homolog of adiponectin. To analyze the role of Osmotin in controlling energy metabolism by suppressing abdominal fat accumulation.

METHODS

We investigated the effects of osmotin in C57BL/6 mice on high-fat diet and in 3T3-L1 adipocytes by Biochemical tests, Immunofluorescence confocal Microscopy, RT-PCR, and Flow cytometry.

RESULTS

In this study, we investigated the anti-obesity effects of osmotin on adipocyte differentiation and regulation of the related factors lipolysis and glucose uptake in 3T3-L1 cells in vitro. Moreover, we analyzed the role of osmotin in prevention of insulin resistance, excess fat accumulation and metabolic syndrome in high-fat diet mouse model via AMPK and MAPK pathways in vivo. In addition, osmotin caused cell cycle arrest in G₀/G₁ phase by regulating expression of p21, p27 and CDK2 and improved glucose control, as concluded from glucose and insulin tolerance tests.

CONCLUSION

These results reveal the role of osmotin in AMPK downstream signaling. These results provide the first indication that osmotin exerts therapeutic effects on obesity, which could promote development of therapeutic aspects for obesity and related diseases.

Ezetimibe ameliorates lipid accumulation during adipogenesis by regulating the AMPK-mTORC1 pathway

Adipogenesis, a critical process that converts adipocyte precursors into adipocytes, is considered a potential therapeutic target for the treatment of obesity. Ezetimibe, a drug approved by the United States Food and Drug Administration, is used for the treatment of hypercholesterolemia. Recently, it was reported to ameliorate high fat diet-induced dyslipidemia in mice and reduce lipid accumulation in hepatocytes through the activation of AMPK. However, the anti-adipogenic effects of ezetimibe and the underlying molecular mechanism have not yet been elucidated. Here, we found that ezetimibe reduced lipid accumulation via activating AMPK during the early phase of adipogenesis. We also observed that ezetimibe inhibited peroxisome proliferator-activated receptor γ, which is a major transcription factor of adipogenesis. Furthermore, ezetimibe-mediated AMPK activation reduced lipid accumulation by inhibiting mTORC1 signaling, leading to the downregulation of lipogenesis-related genes. Mitotic clonal expansion, required for adipogenesis, accelerates cell cycle progression and cell proliferation. We additionally observed that ezetimibe prevented the progression of mitotic clonal expansion by arresting the cell cycle at the G0/G1 phase, which was followed by the inhibition of cell proliferation. Collectively, ezetimibe-mediated inhibition of adipogenesis is dependent on the AMPK-mTORC1 pathway. Thus, we suggest that ezetimibe might be a promising drug for the treatment of obesity.

Synergistic action of Erigeron annuus L. Pers and Borago officinalis L. enhances anti-obesity activity in a mouse model of diet-induced obesity

Prior studies show that Borago officinalis L. (BO) can suppress lipid accumulation in 3 T3-L1 adipocytes. Similarly, we recently revealed that Erigeron annuus L. Pers (EA) can significantly diminish both lipid accumulation and adipocyte differentiation in 3 T3-L1 cells through an AMPK (AMP-activated protein kinase)-dependent mechanism. Accordingly, the objective of this present study was to evaluate the anti-obesity activity of EA and/or BO using an animal model of obesity. Obesity was induced in C57BL/6 J mice by feeding a high-fat diet (HFD; 60 kcal% fat) for 3 weeks, followed by administration of EA and/or BO (100-200 mg/kg body weight) or positive control Garcinia Cambogia (GC) (100 mg/kg body weight) for an additional 8 weeks. The anti-obesity effect of EA and/or BO was assessed by measuring body weight, adipocyte size, lipid accumulation, and expression level of genes associated with adipogenesis. We found the administration of EA and/or BO significantly attenuated increases in body weight gain, adipocyte size, and lipid accumulation in obese mice induced by HFD. In addition, western blot analysis revealed that HFD-mediated increases in expressions levels of adipogenic genes such as PPARγ, C/EBPα, and SREBP-1c were diminished by EA and/or BO. Moreover, EA and/or BO significantly stimulated the production of adiponectin, a unique adipokine known to stimulate the breakdown of fat/lipids, whereas adiponectin levels were reduced in mice fed a HFD. Notably, a combination of EA and BO was more effective at modulating such parameters than EA or BO alone. Taken together, these results demonstrate that an anti-obesity effect of EA and/or BO can reduce adipocyte hypertrophy and modulate the expression of adipogenesis-associated genes.

Ginsenoside Rb1 Induces Beta 3 Adrenergic Receptor-Dependent Lipolysis and Thermogenesis in 3T3-L1 Adipocytes and db/db Mice

Obesity is constantly rising into a major health threat worldwide. Activation of brown-like transdifferentiation of white adipocytes (browning) has been proposed as a promising molecular target for obesity treatment. In this study, we investigated the effect of ginsenoside Rb1 (Rb1), a saponin derived from Panax ginseng Meyer, on browning. We used 3T3-L1 murine adipocytes and leptin receptor mutated db/db mice. The lipid accumulation, AMP-activated protein kinase alpha (AMPKα)-related pathways, lipolytic and thermogenic factors were measured after Rb treatment in 3T3-L1 adipocytes. Body weight change and lipolysis-thermogenesis factors were investigated in Rb1-treated db/db mice. Beta 3 adrenergic receptor activation (β3AR) changes were measured in Rb1-treated 3T3-L1 cells with or without β3AR inhibitor L748337 co-treatment. As a result, Rb1 treatment decreased lipid droplet size in 3T3-L1 adipocytes. Rb1 also induced phosphorylations of AMPKα pathway and sirtuins. Moreover, lipases and thermogenic factors such as uncoupling protein 1 were increased by Rb1 treatment. Through these results, we could expect that the non-shivering thermogenesis program can be induced by Rb1. In db/db mice, 6-week injection of Rb1 resulted in decreased inguinal white adipose tissue (iWAT) weight associated with shrunken lipid droplets and increased lipolysis and thermogenesis. The thermogenic effect of Rb1 was possibly due to β3AR, as L748337 pre-treatment abolished the effect of Rb1. In conclusion, we suggest Rb1 as a potential lipolytic and thermogenic therapeutic agent which can be used for obesity treatment.

Black Raspberry (Rubus coreanus Miquel) Promotes Browning of Preadipocytes and Inguinal White Adipose Tissue in Cold-Induced Mice

The alteration of white adipose tissue (WAT) "browning", a change of white into beige fat, has been considered as a new therapeutic strategy to treat obesity. In this study, we investigated the browning effect of black raspberry (Rubus coreanus Miquel) using in vitro and in vivo models. Black raspberry water extract (BRWE) treatment inhibited lipid accumulation in human mesenchymal stem cells (hMSCs) and zebrafish. To evaluate the thermogenic activity, BRWE was orally administered for 2 weeks, and then, the mice were placed in a 4 °C environment. As a result, BRWE treatment increased rectal temperature and inguinal WAT (iWAT) thermogenesis by inducing the expression of beige fat specific markers such as PR domain zinc-finger protein 16 (PRDM16), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), and t-box protein 1 (TBX1) in cold-exposed mice. Furthermore, ellagic acid (EA), a constituent of BRWE, markedly promoted beige specific markers: UCP1, PGC1α, TBX1, and nuclear respiratory factor 1 in beige differentiation media (DM)-induced 3T3-L1 adipocytes. Our findings indicate that BRWE can promote beige differentiation/activation, and EA is the active compound responsible for such effect. Thus, we suggest the nature-derived agents BRWE and EA as potential agents for obesity treatment.

Bitter Orange (Citrus aurantium Linné) Improves Obesity by Regulating Adipogenesis and Thermogenesis through AMPK Activation

Obesity is a global health threat. Herein, we evaluated the underlying mechanism of anti-obese features of bitter orange (Citrus aurantium Linné, CA). Eight-week-administration of CA in high fat diet-induced obese C57BL/6 mice resulted in a significant decrease of body weight, adipose tissue weight and serum cholesterol. In further in vitro studies, we observed decreased lipid droplets in CA-treated 3T3-L1 adipocytes. Suppressed peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha indicated CA-inhibited adipogenesis. Moreover, CA-treated primary cultured brown adipocytes displayed increased differentiation associated with elevation of thermogenic factors including uncoupling protein 1 and PPARγ coactivator 1 alpha as well. The effects of CA in both adipocytes were abolished in AMP-activated protein kinase alpha (AMPKα)-suppressed environments, suggesting the anti-adipogenic and pro-thermogenic actions of CA were dependent on AMPKα pathway. In conclusion, our results suggest CA as a potential anti-obese agent which regulates adipogenesis and thermogenesis via AMPKα.