Arctigenin Inhibits Adipogenesis by Inducing AMPK Activation and Reduces Weight Gain in High-Fat Diet-Induced Obese Mice

Arctigenin induces activated HSCs quiescence via AMPK-PPARγ pathway to ameliorate liver fibrosis in mice

Arctigenin (ATG), a traditional Chinese herbal medicine, is a natural lignan compound extracted from the seeds of burdock (Arctium lappa L, Asteraceae). As a natural product with multiple biological activities, the effect and mechanism of ATG against liver fibrosis are not fully elucidated yet. In current work, we first discovered that ATG could improve CCl4-induced liver injury reflected by lower plasma ALT and AST levels, liver coefficient and pathological scoring of ballooning. Furthermore, it also could reduce the positive areas of Masson, Sirius red and α-SMA staining, inhibit the expression of fibrosis-related genes (Col1a1, Col3a1, Acta2), and decrease the content of hydroxyproline, indicated ATG treatment had benefits in alleviating CCl4-induced liver fibrosis. In vitro, we observed that ATG can inhibit collagen production stimulated by TGF-β1 in LX2 cells. By analysis of the information obtained from SymMap and GeneCards databases and in vitro validation experiments, ATG was proven to be an indirect PPARγ agonist and its effect on collagen production was dependent on PPARγ. Subsequently, we confirmed that ATG activating AMPK was the contributor of its effect on PPARγ and collagen production. Finally, the transformation of activated hepatic stellate cells was determined after treated with ATG, in which ATG treatment could return activated LX2 cells to quiescence because of the elevated quiescent markers and lipid droplets. Our work has highlighted the potential of ATG in the treatment of liver fibrosis and clarified that ATG can activate AMPK/PPARγ pathway to restore the activated hepatic stellate cell to quiescence thereby improving liver fibrosis.

Extract of Isatidis Radix Inhibits Lipid Accumulation in In Vitro and In Vivo by Regulating Oxidative Stress

Isatidis Radix (IR), the root of Isatis tinctoria L. belonging to Brassicaceae, has been traditionally used as a fever reducer. Although some pharmacological effects, such as anti-diabetes, anti-virus, and anti-inflammatory, have been reported, there is no study on the anti-obesity effect of IR. This study used 3T3-L1 cells, human mesenchymal adipose stem cells (hAMSCs), and a high-fat diet (HFD)-induced obese mouse model to confirm the anti-adipogenic effect of IR. Intracellular lipid accumulation in 3T3-L1 cells and hAMSCs was decreased by IR treatment.IR extract especially suppressed reactive oxygen species (ROS) production through a cluster of differentiation 36 (CD36)-AMP-activated protein kinase (AMPK) pathway. Consequently, the expressions of peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT-enhancer-binding proteins alpha (C/EBPα), and fatty acid synthesis (FAS) were inhibited by IR extract. In addition, β-oxidation-related genes were also decreased by treatment of IR extract. IR inhibited weight gain through this cascade in the HFD-induced obese mouse model. IR significantly suppressed lipid accumulation in epididymal white adipose tissue (eWAT). Furthermore, the administration of IR extract decreased serum free fatty acid (FFA), total cholesterol (TC), and LDL cholesterol, suggesting that it could be a potential drug for obesity by inhibiting lipid accumulation.

The Adipocyte-Macrophage Relationship in Cancer: A Potential Target for Antioxidant Therapy

Obesity has emerged as a major public health concern with a staggering 39% worldwide prevalence as of 2021. Given the magnitude of the problem and considering its association with chronic low-grade systemic inflammation, it does not come as a surprise that obesity is now considered one of the major risk factors for the development of several chronic diseases, such as diabetes, cardiovascular problems, and cancer. Adipose tissue dysfunction in obesity has taken center stage in understanding how changes in its components, particularly adipocytes and macrophages, participate in such processes. In this review, we will initially focus on how changes in adipose tissue upon excess fat accumulation generate endocrine signals that promote cancer development. Moreover, the tumor microenvironment or stroma, which is also critical in cancer development, contains macrophages and adipocytes, which, in reciprocal paracrine communication with cancer cells, generate relevant signals. We will discuss how paracrine signaling in the tumor microenvironment between cancer cells, macrophages, and adipocytes favors cancer development and progression. Finally, as reactive oxygen species participate in many of these signaling pathways, we will summarize the information available on how antioxidants can limit the effects of endocrine and paracrine signaling due to dysfunctional adipose tissue components in obesity.

Arctigenin-containing burdock sprout extract prevents obesity in association with modulation of the gut microbiota in mice

Several studies have suggested that the gut microbiota affect the health of the host. For example, the Firmicutes/Bacteroidetes (F/B) ratio and the proportion of Akkermansia muciniphila in the microbiota have been closely linked to obesity. In this study, we evaluated the effects of an anti-obesity lignan compound, arctigenin (AG), and burdock sprout extract (GSE), which contains AG, on the gut microbiota of an obese mouse model. C57BL/6J mice were fed high-fat, high-sucrose (HFHS) diets containing AG, GSE, or metformin (MF) for 8 weeks. The composition of the gut microbiota and the cecal content of short-chain fatty acids (SCFAs) were determined using 16S rRNA gene sequencing and high-performance liquid chromatography, respectively. Body weight gain was significantly suppressed in mice treated with AG, GSE, and MF. Analysis of the gut microbiota revealed that the F/B ratio was significantly reduced in the AG- and GSE-treated groups. Furthermore, the copy number of A. muciniphila in the feces was significantly increased in obese mice treated with AG and GSE. In addition, the amount of SCFAs (acetic, propionic, and butyric acids) in the cecal content and their fecal excretions were also significantly increased following AG and GSE treatment. Taken together, these results suggest that AG and GSE prevent obesity by improving the composition of the gut microbiota. Moreover, AG promoted the growth of A. muciniphila in vitro. Thus, AG and GSE may function as novel prebiotic supplements to ameliorate obesity, constipation, and intestinal disorders.

Characteristics and regulation of mesenchymal stem cell plasticity by the microenvironment — specific factors involved in the regulation of MSC plasticity

Mesenchymal stem cells (MSCs), multipotent stromal cells, have attracted extensive attention in the field of regenerative medicine and cell therapy due to the capacity of self-renewal, multilineage differentiation, and immune regulation. MSCs have different cellular effects in different diseases, and even have markedly different curative effects with different tissue sources, indicating the plasticity of MSCs. The phenotypes, secreted factors, and proliferative, migratory, differentiating, and immunomodulatory effects of MSCs depend on certain mediators present in their microenvironment. Understanding microenvironmental factors and their internal mechanisms in MSC responses may help in subsequent prediction and improvement of clinical benefits. This review highlighted the recent advances in MSC plasticity in the physiological and pathological microenvironment and multiple microenvironmental factors regulating MSC plasticity. It also highlighted some progress in the underlying molecular mechanisms of MSC remodeling in the microenvironment. It might provide references for the improvement in vitro culture of MSCs, clinical application, and in vivo induction.

A Comprehensive Review on Anti-obesity Potential of Medicinal Plants and their Bioactive Compounds

Background:

Obesity is a complex health and global epidemic issue. It is an increasing global health challenge covering significant social and economic costs. Abnormal accumulation of fat in the body may increase the health risks including diabetes, hypertension, osteoarthritis, sleep apnea, cardiovascular diseases, stroke and cancer. Synthetic drugs available on the market reported to have several side effects. Therefore, the management of obesity got to involve the traditional use of medicinal plants which helps to search the new therapeutic targets and supports the research and development of anti-obesity drugs.

Objective:

This review aim to update the data and provide a comprehensive report of currently available knowledge of medicinal plants and phyto-chemical constituents reported for their anti-obesity activity.

Methodology:

An electronic search of the periodical databases like Web of Science, Scopus, PubMed, Scielo, Niscair, ScienceDirect, Springerlink, Wiley, SciFinder and Google Scholar with information reported the period 1991-2019, was used to retrieve published data.

Results:

A comprehensive report of the present review manuscript is an attempt to list the medicinal plants with anti-obesity activity. The review focused on plant extracts, isolated chemical compounds with their mechanism of action and their preclinical experimental model, clinical studies for further scientific research.

Conclusion:

This review is the compilation of the medicinal plants and their constituents reported for the managements of obesity. The data will fascinate the researcher to initiate further research that may lead to the drug for the management of obesity and their associated secondary complications. Several herbal plants and their respective lead constituents were also screened by preclinical In-vitro and In-vivo, clinical trials and are effective in the treatment of obesity. Therefore, there is a need to develop and screen large number of plant extracts and this approach can surely be a driving force for the discovery of anti-obesity drugs from medicinal plants.

AMPK/SIRT1 Pathway is Involved in Arctigenin-Mediated Protective Effects Against Myocardial Ischemia-Reperfusion Injury

Arctigenin, one of the active ingredients extracted from Great Burdock (Arctium lappa) Achene, has been found to relieve myocardial infarction injury. However, the specific mechanism of Arctigenin against myocardial infarction remains largely unknown. Here, both acute myocardial ischemia-reperfusion injury (AMI/R) rat model and oxygen glucose deprivation (OGD)-induced myocardial cell injury model were constructed to explore the underlying role of AMPK/SIRT1 pathway in Arctigenin-mediated effects. The experimental data in our study demonstrated that Arctigenin ameliorated OGD-mediated cardiomyocytes apoptosis, inflammation and oxidative stress in a dose-dependent manner. Besides, Arctigenin activated AMPK/SIRT1 pathway and downregulated NF-κB phosphorylation in OGD-treated cardiomyocytes, while inhibiting AMPK or SIRT1 by the Compound C (an AMPK inhibitor) or SIRT1-IN-1 (a SIRT1 inhibitor) significantly attenuated Arctigenin-exerted protective effects on cardiomyocytes. In the animal experiments, Arctigenin improved the heart functions and decreased infarct size of the AMI/R-rats, accompanied with downregulated oxidative stress, inflammation and apoptotic levels in the heart tissues. What's more, Arctigenin enhanced the AMPK/SIRT1 pathway and repressed NF-κB pathway activation. Taken together, our data indicated that Arctigenin reduced cardiomyocytes apoptosis against AMI/R-induced oxidative stress and inflammation at least via AMPK/SIRT1 pathway.

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.

The Extract of Arctium lappa L. Fruit (Arctii Fructus) Improves Cancer-Induced Cachexia by Inhibiting Weight Loss of Skeletal Muscle and Adipose Tissue

Background: Cachexia induced by cancer is a systemic wasting syndrome and it accompanies continuous body weight loss with the exhaustion of skeletal muscle and adipose tissue. Cancer cachexia is not only a problem in itself, but it also reduces the effectiveness of treatments and deteriorates quality of life. However, effective treatments have not been found yet. Although Arctii Fructus (AF) has been studied about several pharmacological effects, there were no reports on its use in cancer cachexia. Methods: To induce cancer cachexia in mice, we inoculated CT-26 cells to BALB/c mice through subcutaneous injection and intraperitoneal injection. To mimic cancer cachexia in vitro, we used conditioned media (CM), which was CT-26 colon cancer cells cultured medium. Results: In in vivo experiments, AF suppressed expression of interleukin (IL)-6 and atrophy of skeletal muscle and adipose tissue. As a result, the administration of AF decreased mortality by preventing weight loss. In adipose tissue, AF decreased expression of uncoupling protein 1 (UCP1) by restoring AMP-activated protein kinase (AMPK) activation. In in vitro model, CM increased muscle degradation factors and decreased adipocytes differentiation factors. However, these tendencies were ameliorated by AF treatment in C2C12 myoblasts and 3T3-L1 cells. Conclusion: Taken together, our study demonstrated that AF could be a therapeutic supplement for patients suffering from cancer cachexia.

Arctigenin prevents the progression of osteoarthritis by targeting PI3K/Akt/NF-κB axis: In vitro and in vivo studies

Osteoarthritis (OA), which is principally featured by progressive joint metabolic imbalance and subsequent degeneration of articular cartilage, is a common chronic joint disease. Arctigenin (ATG), a dietary phyto-oestrogen, has been described to have potent anti-inflammatory effects. Nevertheless, its protective effects on OA have not been clearly established. The target of our following study is to evaluate the protective effects of ATG on IL-1β-induced human OA chondrocytes and mouse OA model. Our results revealed that the ATG pre-treatment effectively decreases the level of pro-inflammatory mediators, such as prostaglandin E2 (PGE2), nitrous oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and tumour necrosis factor alpha (TNF-α) in IL-1β-induced human chondrocytes. In addition, ATG protects against the degradation of extracellular matrix (ECM) under the stimulation of IL-1β and the possible mechanism might be connected with the inactivation of phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor-kappa B (NF-κB) axis. Furthermore, a powerful binding capacity between ATG and PI3K was also uncovered in our molecular docking research. Meanwhile, ATG may act as a protector on the mouse OA model. Collectively, all these findings suggest that ATG could be utilized as a promising therapeutic agent for the treatment of OA.

Inhibition of the PI3K-AKT-mTOR pathway suppresses the adipocyte-mediated proliferation and migration of breast cancer cells

Objective: Although it is well known that adipocyte significantly affects breast cancer progression, its mechanism has not been fully understood. Here, we analyzed the effect of adipocytes on breast cancer progression including cell proliferation and migration. Materials and Methods: We treated the conditioned media obtained from mouse 3T3-L1-derived or human adipose tissue-derived mesenchymal stem cells (hAMSC)-derived adipocytes to breast cancer cells, MCF-7 and MDA-MB-231. And then, cells viability and proliferation were analyzed using MTT assays and colony forming assays, respectively. Also mRNA expression of inflammatory cytokines and proteins expression in main signal pathway were analyzed by RT-qPCR and immunoblotting, respectively. Results: Adipocyte-derived conditioned media increased the proliferation and migration of MCF-7 and MDA-MB-231 cells while little effects in a human normal immortalized mammary epithelial cell line MCF10A. In addition, adipocyte-derived conditioned media induced phosphorylation of AKT and mTOR and upregulated the expression of target genes of the PI3K-AKT-mTOR pathway including IL6, IL1β, IL1α and TNFα in breast cancer cells. Furthermore, BEZ235 a dual inhibitor of PI3K and mTOR significantly decreased the adipocyte-mediated the proliferation and migration of breast cancer cells. Conclusion: Adipocyte-derived conditioned media enhance the proliferation and migration of breast cancer cells through the PI3K-AKT-mTOR pathway, supporting the importance of heterotypic interactions between breast cancer cells and adipocytes in the tumor microenvironment.

Small molecules for mesenchymal stem cell fate determination

Mesenchymal stem cells (MSCs) are adult stem cells harboring self-renewal and multilineage differentiation potential that are capable of differentiating into osteoblasts, adipocytes, or chondrocytes in vitro, and regulating the bone marrow microenvironment and adipose tissue remodeling in vivo. The process of fate determination is initiated by signaling molecules that drive MSCs into a specific lineage. Impairment of MSC fate determination leads to different bone and adipose tissue-related diseases, including aging, osteoporosis, and insulin resistance. Much progress has been made in recent years in discovering small molecules and their underlying mechanisms control the cell fate of MSCs both in vitro and in vivo. In this review, we summarize recent findings in applying small molecules to the trilineage commitment of MSCs, for instance, genistein, medicarpin, and icariin for the osteogenic cell fate commitment; isorhamnetin, risedronate, and arctigenin for pro-adipogenesis; and atractylenolides and dihydroartemisinin for chondrogenic fate determination. We highlight the underlying mechanisms, including direct regulation, epigenetic modification, and post-translational modification of signaling molecules in the AMPK, MAPK, Notch, PI3K/AKT, Hedgehog signaling pathways etc. and discuss the small molecules that are currently being studied in clinical trials. The target-based manipulation of lineage-specific commitment by small molecules offers substantial insights into bone marrow microenvironment regulation, adipose tissue homeostasis, and therapeutic strategies for MSC-related diseases.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

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.

Rubrofusarin-6-β-gentiobioside inhibits lipid accumulation and weight gain by regulating AMPK/mTOR signaling

BACKGROUND

Although rubrofusarin-6-β-gentiobioside (RFG), which is a component of Cassiae tora seed, could likely regulate hyperlipidemia, its anti-obesity effect and related mechanism have not been elucidated.

PURPOSE

The aim of this study was to examine whether RFG can ameliorate obesity and the mechanism of lipid accumulation regulated by RFG.

STUDY DESIGN

In in vitro experiments, we confirmed the anti-adipogenic effect of RFG using 3T3-L1 cells and human adipose mesenchymal stem cells (hAMSCs). To confirm the anti-obesity effect, High-Fat Diet (HFD)-induced obese mice were selected as a model.

METHODS

We investigated anti-adipogenic effects of RFG using MTS assay, Oil Red O Staining, real-time RT-PCR, western blot analysis, and immunofluorescence staining. The anti-obesity effect of RFG was confirmed in HFD-induced mice model using hematoxylin and eosin staining and serum analysis.

RESULTS

RFG inhibited lipid accumulation in 3T3-L1 cells and hAMSCs by reducing expression of mammalian targets of rapamycin (mTOR), peroxisome proliferator-activated receptor (PPAR)γ, and CCAAT-enhancer binding protein (C/EBP)α. RFG phosphorylated AMP-activated protein kinase (AMPK) in a liver kinase B (LKB) 1-independent manner. Moreover, the anti-adipogenic effect of RFG was blocked by AMPK inhibitor. These results suggest that RFG inhibits lipid accumulation via AMPK signaling. Furthermore, RFG reduced the body weight, size of epididymal white adipose tissue (eWAT), and fatty liver in the mice. RFG also suppressed levels of adipogenic factors PPARγ, C/EBPα, FAS, LPL, and aP2) by activating AMPK in the eWAT and liver.

CONCLUSION

RFG can ameliorate obesity, and thus, could be used as a therapeutic agent for treating obesity.

Arctigenin improves lipid metabolism by regulating AMP-activated protein kinase and downstream signaling pathways

Although it has been reported that arctigenin (ARG) can reduce the body weight and inhibit adipogenic differentiation by activating AMP-activated protein kinase (AMPK), the exact signals responsible for the ARG-mediated antiobesity mechanism through AMPK are not well understood. In this study, we investigated the potential improvement of AGR on lipid metabolism using a high-fat diet (HFD)-induced hyperlipidemia rats and 3T3-L1 mature adipocytes. The levels of AMPK and its downstream factors were examined by Western blot analysis and real-time fluorescent quantitative polymerase chain reaction. We observed that ARG lowered the HFD-induced body weight and the levels of serum lipid. Moreover, ARG clearly alleviated fat deposition in the liver and reduced epididymal fat accumulation. ARG also suppressed lipogenesis and lipolysis but promoted fatty acid β-oxidation in adipocytes. Most importantly, ARG increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) and upregulated the messenger RNA levels of downstream genes related to fatty acid β-oxidation, such as carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 but downregulated the expression of peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding transcription factor 1 (SREBP1c) and their targets, including lipogenesis-related genes such as CCAAT/enhancer-binding protein α, lipoprotein lipase, adipocyte protein 2, and fatty acid synthase (FAS), as well as lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase. The activity of FAS was also decreased by ARG. We conclude that AMPK activation is important for the pharmacological effects of ARG. ARG may improve lipid metabolism by regulating the AMPK-ACC and AMPK-PPARγ/SREBP1c signaling pathways.

The antitumor function of arctigenin in human retinoblastoma cells is mediated by jagged‑1

Retinoblastoma is an intraocular malignant tumor that may severely affect vision and represents a life‑threatening disease in children. Arctigenin (ATG) is an active compound that exhibits numerous pharmacological activities, which is isolated from the seeds of greater burdock (Arctium lappa Linnaeus), a plant used in traditional Chinese herbal medicine. The present study aimed to investigate the effects of ATG on cancer progression by analyzing the retinoblastoma cell line Y79. ATG exhibited a significant inhibitory effect on the viability of Y79 cells in a dose‑dependent manner. Furthermore, treatment with ATG promoted apoptosis, and increased the protein expression levels of B‑cell lymphoma 2 (BCL‑2)‑associated X protein and decreased the protein expression levels of BCL‑2. Cell migration was suppressed following treatment with ATG, as assessed by Transwell migration assay. Furthermore, the protein expression levels of jagged‑1 (JAG1) were decreased, and various factors involved in the Notch signaling pathway, including the Notch intracellular domain (NICD), transcription factor HES (HES)5 and HES1 were downregulated following treatment with ATG. The decreased expression levels of JAG1 were restored in response to JAG1 overexpression, alongside increases in the protein expression levels of NICD, HES5 and HES1. Furthermore, overexpression of JAG1 partly restored the cell viability and migration suppressed following treatment with ATG. In addition, ATG‑induced apoptosis was reduced by JAG1 overexpression. Collectively, the present results suggested that ATG may serve as an antitumor compound by suppressing the proliferation and migration of retinoblastoma cells, inducing apoptosis, downregulating the protein expression levels of JAG1, and decreasing the activity of the Notch signaling pathway.

Conditioned media from adipocytes promote proliferation, migration, and invasion in melanoma and colorectal cancer cells

Epidemiological evidence suggests that obesity can significantly increase the risk of various cancers, although the mechanisms underlying this link are completely unknown. Here, we analyzed the effect of adipocytes on melanoma and colon cancer cells proliferation, migration, and invasion. The potential effects of conditioned media (CM) obtained from differentiated mouse 3T3-L1 cells and human adipose tissue-derived mesenchymal stem cells (hAMSC) on the proliferation, migration, and invasion of B16BL6 melanoma and colon 26-L5 cancer cells were investigated. The 3T3-L1 and hAMSC CM increased cell proliferation, migration, and invasion in both the cell lines. In addition, adipocytes CM increased matrix metalloproteinase 9 (MMP-9) and MMP-2 activity in both B16BL6 and colon 26-L5 cells. These effects were found to be associated with an increased expression of various oncogenic proteins in B16BL6 and colon 26-L5 cells. Also, adipocyte CM induced Akt and mTOR activation in both tumor cell lines, and the pharmacological inhibition of Akt and mTOR blocked the CM induced Akt as well as mTOR activation and CM-stimulated melanoma and colon cancer cell proliferation, migration, and invasion. These data suggest that adipocyte promotes melanoma and colon cancer progression through modulating the expression of diverse proteins associated with cancer growth and metastasis as well as modulation of the Akt/mTOR signaling.

LY3009120, a pan-Raf kinase inhibitor, inhibits adipogenesis of 3T3-L1 cells by controlling the expression and phosphorylation of C/EBP-α, PPAR-γ, STAT‑3, FAS, ACC, perilipin A, and AMPK

Excessive preadipocyte differentiation/adipogenesis is closely linked to the development of obesity. LY3009120 is a pan‑Raf kinase inhibitor and is known for its anticancer activities. In the present study, the effect of LY3009120 on 3T3‑L1 cell adipogenesis was investigated. The differentiation of 3T3‑L1 preadipocytes into adipocytes was measured by Oil Red O staining and AdipoRed assay. Changes of cellular protein expression and phosphorylation levels in differentiating 3T3‑L1 preadipocytes in the absence or presence of LY3009120 were determined by western blotting analysis. Cell count assay was used to assess the cytotoxicity of LY3009120 on 3T3‑L1 cells. At 0.3 µM, LY3009120 markedly inhibited lipid accumulation and decreased triglyceride content in differentiating 3T3‑L1 cells. However, it had minimal effect on the elevated expression and phosphorylation of three Raf kinase isoforms (C‑Raf, A‑Raf, and B‑Raf) observed in the cells. LY3009120 reduced not only the expression of CCAAT/enhancer‑binding protein‑α (C/EBP‑α), peroxisome proliferator‑activated receptor‑γ (PPAR‑γ), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), and perilipin A, but also reduced the phosphorylation of signal transducer and activator of transcription‑3 (STAT‑3) in differentiating 3T3‑L1 cells. LY3009120 also increased the phosphorylation of adenosine 3',5'‑cyclic monophosphate (cAMP)‑activated protein kinase (AMPK), but did not affect the phosphorylation or expression of liver kinase B1 in these cells. In summary, this is the first report, to the best of our knowledge, demonstrating that LY3009120 has an anti‑adipogenic effect on 3T3‑L1 cells, which may be mediated through control of the expression and phosphorylation of C/EBP‑α, PPAR‑γ, STAT‑3, FAS, ACC, perilipin A, and AMPK.

Rosmarinic Acid Activates AMPK to Inhibit Metastasis of Colorectal Cancer

Rosmarinic acid (RA) has been used as an anti-inflammatory, anti-diabetic, and anti-cancer agent. Although RA has also been shown to exert an anti-metastatic effect, the mechanism of this effect has not been reported to be associated with AMP-activated protein kinase (AMPK). The aim of this study was to elucidate whether RA could inhibit the metastatic properties of colorectal cancer (CRC) cells via the phosphorylation of AMPK. RA inhibited the proliferation of CRC cells through the induction of cell cycle arrest and apoptosis. In several metastatic phenotypes of CRC cells, RA regulated epithelial-mesenchymal transition (EMT) through the upregulation of an epithelial marker, E-cadherin, and the downregulation of the mesenchymal markers, N-cadherin, snail, twist, vimentin, and slug. Invasion and migration of CRC cells were inhibited and expressions of matrix metalloproteinase (MMP)-2 and MMP-9 were decreased by RA treatment. Adhesion and adhesion molecules such as ICAM-1 and integrin β1 expressions were also reduced by RA treatment. In particular, the effects of RA on EMT and MMPs expressions were due to the activation of AMPK. Moreover, RA inhibited lung metastasis of CRC cells by activating AMPK in mouse model. Collectively, these results proved that RA could be potential therapeutic agent against metastasis of CRC.

Inhibition of Mast Cell-Mediated Allergic Responses by Arctii Fructus Extracts and Its Main Compound Arctigenin

The Arctium lappa seeds (Arctii Fructus) and its major active compound, arctigenin (ARC), are known to have anticancer, antiobesity, antiosteoporosis, and anti-inflammatory activities. However, the effect of Arctii Fructus and ARC on mast cell-mediated allergic inflammation and its associated mechanism have not been elucidated. Therefore, we attempted to investigate the antiallergic activity of Arctii Fructus and ARC on mast cells and experimental mouse models. Arctii Fructus water extract (AFW) or ethanol extract (AFE) and ARC reduced the production of histamine and pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, IL-8, and TNF-α in mast cells. AFW, AFE, and ARC inhibited phosphorylation of MAPKs and NF-κB in activated mast cells. Moreover, IgE-mediated passive cutaneous anaphylaxis and compound 48/80-induced anaphylactic shock were suppressed by AFW, AFE, and ARC administration. These results suggest that Arctii Fructus and ARC are potential therapeutic agents against allergic inflammatory diseases.

Farnesol Has an Anti-obesity Effect in High-Fat Diet-Induced Obese Mice and Induces the Development of Beige Adipocytes in Human Adipose Tissue Derived-Mesenchymal Stem Cells

Brown adipocytes dissipate energy as heat and hence have an important therapeutic capacity for obesity. Development of brown-like adipocytes (also called beige) is also another attractive target for obesity treatment. Here, we investigated the effect of farnesol, an isoprenoid, on adipogenesis in adipocytes and on the browning of white adipose tissue (WAT) as well as on the weight gain of high-fat diet (HFD)-induced obese mice. Farnesol inhibited adipogenesis and the related key regulators including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α through the up-regulation of AMP-activated protein kinase in 3T3-L1 murine adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs). Farnesol markedly increased the expression of uncoupling protein 1 and PPARγ coactivator 1 α in differentiated hAMSCs. In addition, farnesol limited the weight gain in HFD obese mice and induced the development of beige adipocytes in both inguinal and epididymal WAT. These results suggest that farnesol could be a potential therapeutic agent for obesity treatment.

Arctigenin improves vascular tone and decreases inflammation in human saphenous vein

The goal of this study was to test the effects of bioactive phenylpropanoid dibenzylbutyrolactone lignan arctigenin (ATG) in vascular tone. Human bypass graft vessel, from a saphenous vein (SV), were set up in organ bath system and contracted with potassium chloride (KCl, 40mM). Two concentration-response curves of noradrenaline (NE) (10nM-100μM) separated with an incubation period of 30min without (Control) or with ATG (3-100μM) were established. Inhibitors of nitric oxide, prostaglandins, K⁺ related channels or calcium influx were used to delineate the molecular mechanisms beyond ATG effects. To investigate anti-inflammatory actions, SV were treated with 10μM or 100μM ATG and incubated for 18h in the absence or presence of both interleukin-1beta (IL-1β) and lipopolysaccharide (LPS) to mimic the physiological or inflamed tissue conditions. Proatherogenic and inflammatory mediators İnterleukine-1 beta (IL-1β), Monocyte Chemoattractant Proteine-1 (MCP-1), Tumor Necrosis Factor- α (TNF-α), İnterleukine-6 (IL-6), Prostaglandin E₂ (PGE₂) and İnterleukine-8 (IL-8) in the supernatant were measured. ATG significantly decreased vascular contractile response to NE. Moreover, it reduced contractions induced by KCl and cumulative addition of CaCl_2. The mediators were significantly increased in inflammatory conditions compared to normal conditions, an effect which was inhibited by ATG (10 and 100µM). ATG reduces contractions in SV and decreases the production of proinflammatory-proatherogenic mediators, setting the stage for further evaluating the effect of ATG in cardiovascular diseases.

Pyrocincholic acid 3β-O-β-D-quinovopyranosyl-28-O-β-D-glucopyranoside suppresses adipogenesis and regulates lipid metabolism in 3T3-L1 adipocytes

Obesity is crucially involved in many metabolic diseases, such as type 2 diabetes, cardiovascular disease and cancer. Regulating the number or size of adipocytes has been suggested to be a potential treatment for obesity. In this study, we investigated the effect of pyrocincholic acid 3β-O-β-D-quinovopyranosyl-28-O-β-D-glucopyranoside (PAQG), a 27-nor-oleanolic acid saponin extracted from Metadina trichotoma, on adipogenesis and lipid metabolism in 3T3-L1 adipocytes. The 3T3-L1 pre-adipocytes were incubated with vehicle or PAQG for 6 days in differentiation process. PAQG significantly reduced the adipogenesis, adiponectin secretion and the expression level of key transcription factors related to adipogenesis, such as PPARγ, C/EBPβ, C/EBPα, and FABP4. Moreover, PAQG increased the levels of FFA and glycerol in medium and reduced TG level in mature adipocytes. Interestingly, PAQG not only promoted the activation of AMPK and genes involved in fatty oxidation including PDK4 and CPT1a, but also inhibited those genes involved in fatty acid biosynthesis, such as SREBP1c, FAS, ACCα and SCD1. In conclusion, PAQG inhibits the differentiation and regulates lipid metabolism of 3T3-L1 cells via AMPK pathway, suggesting that PAQG may be a novel and promising natural product for the treatment of obesity and hyperlipidemia.

β-Catenin Mediates Anti-adipogenic and Anticancer Effects of Arctigenin in Preadipocytes and Breast Cancer Cells

Arctigenin is a lignan abundant in Asteraceae plants and has anti-inflammatory, antiobesity, and anticancer activities. Obesity is one of the leading causes of several types of cancers including breast cancer. The current study was performed to investigate if arctigenin suppresses differentiation of preadipocytes and proliferation of breast cancer cells and to explore potential molecular mechanisms. Treatment of arctigenin reduced lipid accumulation in differentiated 3T3-L1 adipocytes in a dose- and time-dependent manner without toxicity. Arctigenin suppressed the expression of peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT/enhancer-binding protein-alpha (C/EBPα), perilipin, and fatty acid binding protein 4 (FABP4) in a dose-dependent manner in differentiated 3T3-L1 cells. Both total and unphosphorylated (active) β-catenin were increased in whole cell lysates and the nuclear fraction of differentiated 3T3-L1 cells treated with 25 μM arctigenin. On the other hand, arctigenin decreased proliferation of two human breast cancer cells (MCF-7 and MDA-MB-231). Arctigenin induced apoptosis and decreased expression of total and unphosphorylated (active) β-catenin and cyclin D1 in MCF-7, but not in MDA-MB-231. These data indicate that arctigenin suppressed adipogenesis in preadipocytes and activated apoptosis in estrogen receptor (ER) positive breast cancer cells through modulating expression of β-catenin.

Arctigenin protects against neuronal hearing loss by promoting neural stem cell survival and differentiation

Neuronal hearing loss has become a prevalent health problem. This study focused on the function of arctigenin (ARC) in promoting survival and neuronal differentiation of mouse cochlear neural stem cells (NSCs), and its protection against gentamicin (GMC) induced neuronal hearing loss. Mouse cochlea was used to isolate NSCs, which were subsequently cultured in vitro. The effects of ARC on NSC survival, neurosphere formation, differentiation of NSCs, neurite outgrowth, and neural excitability in neuronal network in vitro were examined. Mechanotransduction ability demonstrated by intact cochlea, auditory brainstem response (ABR), and distortion product optoacoustic emissions (DPOAE) amplitude in mice were measured to evaluate effects of ARC on GMC-induced neuronal hearing loss. ARC increased survival, neurosphere formation, neuron differentiation of NSCs in mouse cochlear in vitro. ARC also promoted the outgrowth of neurites, as well as neural excitability of the NSC-differentiated neuron culture. Additionally, ARC rescued mechanotransduction capacity, restored the threshold shifts of ABR and DPOAE in our GMC ototoxicity murine model. This study supports the potential therapeutic role of ARC in promoting both NSCs proliferation and differentiation in vitro to functional neurons, thus supporting its protective function in the therapeutic treatment of neuropathic hearing loss in vivo.

Arctigenin Inhibits Lung Metastasis of Colorectal Cancer by Regulating Cell Viability and Metastatic Phenotypes

Arctigenin (ARC) has been shown to have an anti-cancer effect in various cell types and tissues. However, there have been no studies concerning metastatic colorectal cancer (CRC). In this study, we investigated the anti-metastatic properties of ARC on colorectal metastasis and present a potential candidate drug. ARC induced cell cycle arrest and apoptosis in CT26 cells through the intrinsic apoptotic pathway via MAPKs signaling. In several metastatic phenotypes, ARC controlled epithelial-mesenchymal transition (EMT) through increasing the expression of epithelial marker E-cadherin and decreasing the expressions of mesenchymal markers; N-cadherin, vimentin, β-catenin, and Snail. Moreover, ARC inhibited migration and invasion through reducing of matrix metalloproteinase-2 (MMP-2) and MMP-9 expressions. In an experimental metastasis model, ARC significantly inhibited lung metastasis of CT26 cells. Taken together, our study demonstrates the inhibitory effects of ARC on colorectal metastasis.

Anti-adipogenic effect of Glycoside St-E2 and Glycoside St-C1 isolated from the leaves of Acanthopanax henryi (Oliv.) Harms in 3T3-L1 cells

Acanthopanax henryi (Oliv.) Harms has been used in the treatment of arthritis, rheumatism, and abdominal pain. This study evaluated whether natural compounds isolated from the leaves of A. henryi (Oliv.) Harms could inhibit adipocyte differentiation by regulating transcriptional factors such as peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα). AMP-activated protein kinase (AMPK) activity was also evaluated. Among the several compounds isolated from the leaves of A. henryi (Oliv.) Harms, Glycoside St-C1 and Glycoside St-E2 significantly decreased lipid accumulation and the expressions of PPARγ and C/EBPα. Glycoside St-C1 and Glycoside St-E2 were found to activate AMPK when they regulated PPARγ and C/EBPα. Results confirmed that Glycoside St-C1 and Glycoside St-E2 isolated from the leaves of A. henryi (Oliv.) Harms can inhibit adipogenesis through the AMPK-PPARγ-C/EBPα mechanism. Thus, this study suggests that Glycoside St-C1 and Glycoside St-E2 have a therapeutic effect due to activation of the AMPKα.

Anti-obesity effects of Arctii Fructus (Arctium lappa) in white/brown adipocytes and high-fat diet-induced obese mice

Arctii Fructus prevents the development of obesity through the regulation of white/brown adipocytes.