Obesity has been often associated with the occurrence of cardiovascular diseases, type 2 diabetes, and cancer. The development of obesity is also accompanied by significant differentiation of preadipocytes into adipocytes. In this study, we investigated the activity of α-mangostin, a major xanthone component isolated from the stem bark of G. malaccensis, on glucose uptake and adipocyte differentiation of 3T3-L1 cells focusing on PPARγ, GLUT4, and leptin expressions. α-Mangostin was found to inhibit cytoplasmic lipid accumulation and adipogenic differentiation. Cells treated with 50 μM of α-mangostin reduced intracellular fat accumulation dose-dependently up to 44.4% relative to MDI-treated cells. Analyses of 2-deoxy-D-[(3)H] glucose uptake activity showed that α-mangostin significantly improved the glucose uptake (P < 0.05) with highest activity found at 25 μM. In addition, α-mangostin increased the amount of free fatty acids (FFA) released. The highest glycerol release level was observed at 50 μM of α-mangostin. qRT-PCR analysis showed reduced lipid accumulation via inhibition of PPARγ gene expression. Induction of glucose uptake and free fatty acid release by α-mangostin were accompanied by increasing mRNA expression of GLUT4 and leptin. These evidences propose that α-mangostin might be possible candidate for the effective management of obesity in future.
Diabesity is the combination of type 2 diabetes and obesity characterized by chronic low-grade inflammation. The Wnt signaling act as an evolutionary pathway playing crucial role in regulating cellular homeostasis and energy balance from hypothalamus to metabolic organs. Aberrant activity of certain appendages in the canonical and non-canonical Wnt system deregulates metabolism and leads to adipose tissue expansion, this key event initiates metabolic stress causing metaflammation and obesity. Metaflammation induced obesity initiates abnormal development of adipocytes mediating through the non-canonical Wnt signaling inhibition of canonical Wnt pathway to fan the flames of adipogenesis. Moreover, activation of toll like receptor (TLR)-4 signaling in metabolic stress invites immune cells to release pro-inflammatory cytokines for recruitment of macrophages in adipose tissues, further causes polarization of macrophages into M1(classically activated) and M2 (alternatively activated) subtypes. These events end with chronic low-grade inflammation which interferes with insulin signaling in metabolic tissues to develop type 2 diabetes. However, there is a dearth in understanding the exact mechanism of Wnt-TLR axis during diabesity. This review dissects the molecular facets of Wnt and TLRs that modulates cellular components during diabesity and provides current progress, challenges and alternative therapeutic strategies at preclinical and clinical level.
The increased prevalence of obesity and associated insulin resistance calls for effective therapeutic treatment of metabolic diseases. The current PPARγ-targeting antidiabetic drugs have undesirable side effects. The present study investigated the anti-diabetic and anti-obesity effects of withaferin A (WFA) in diet-induced obese (DIO) C57BL/6J mice and also the anti-adipogenic effect of WFA in differentiating 3T3- F442A cells. DIO mice were treated with WFA (6 mg/kg) or rosiglitazone (10 mg/kg) for 8 weeks. At the end of the treatment period, metabolic profile, liver function and inflammatory parameters were obtained. Expression of selective genes controlling insulin signaling, inflammation, adipogenesis, energy expenditure and PPARγ phosphorylation-regulated genes in epididymal fats were analyzed. Furthermore, the anti-adipogenic effect of WFA was evaluated in 3T3- F442A cell line. WFA treatment prevented weight gain without affecting food or caloric intake in DIO mice. WFA-treated group also exhibited lower epididymal and mesenteric fat pad mass, an improvement in lipid profile and hepatic steatosis and a reduction in serum inflammatory cytokines. Insulin resistance was reduced as shown by an improvement in glucose and insulin tolerance and serum adiponectin. WFA treatment upregulated selective insulin signaling (insr, irs1, slc2a4 and pi3k) and PPARγ phosphorylation-regulated (car3, selenbp1, aplp2, txnip, and adipoq) genes, downregulated inflammatory (tnf-α and il-6) genes and altered energy expenditure controlling (tph2 and adrb3) genes. In 3T3- F442A cell line, withaferin A inhibited adipogenesis as indicated by a decrease in lipid accumulation in differentiating adipocytes and protein expression of PPARγ and C/EBPα. The effect of rosiglitazone on physiological and lipid profiles, insulin resistance, some genes expression and differentiating adipocytes were markedly different. Our data suggest that WFA is a promising therapeutic agent for both diabetes and obesity.
Trigonelline is a natural alkaloid mainly found in Trigonella Foenum Graecum (fenugreek) Fabaceae and other edible plants with a variety of medicinal applications. Therefore, we investigated the molecular mechanism of trigonelline (TG) on the inhibition of adipocyte differentiation and lipid accumulation in 3T3-L1 cells. Trigonelline suppressed lipid droplet accumulation in a concentration (75 and 100 μM) dependent manner. Treatment of adipocyte with of TG down regulates the peroxisome proliferator-activated receptor (PPARγ) and CCAAT element binding protein (C/EBP-α) mRNA expression, which leads to further down regulation of other gene such as adiponectin, adipogenin, leptin, resistin and adipocyte fatty acid binding protein (aP2) as compared with respective control cells on 5th and 10th day of differentiation. Further, addition of triognelline along with troglitazone to the adipocyte attenuated the troglitazone effects on PPARγ mediated differentiation and lipid accumulation in 3T3-L1 cells. Trigonelline might compete against troglitazone for its binding to the PPARγ. In addition, adipocyte treated with trigonelline and isoproterenol separately. Isoproterenol, a lipolytic agent which inhibits the fatty acid synthase and GLUT-4 transporter expression via cAMP mediated pathway, we found that similar magnitude response of fatty acid synthase and GLUT-4 transporter expression in trigonelline treated adipocyte. These results suggest that the trigonelline inhibits the adipogenesis by its influences on the expression PPARγ, which leads to subsequent down regulation of PPAR-γ mediated pathway during adipogenesis. Our findings provide key approach to the mechanism underlying the anti-adipogenic activity of trigonelline.
Despite many treatment options, cancer remains a growing problem and has become the second leading cause of death globally. Here, we present fluorescence molecular tomography (FMT) data regarding the reversion of third generation co-cultured U87+DBTRG and patient-derived GBM tumor model after treatment with novel IL17A inhibitor named FLVM and FLVZ (organic derivatives of caffeic acid). FMT was used to determine tumor angiogenesis volume (assessment of number of blood vessel; the expression of angiogenic factors CD34 and other angiogenic cancer bio-markers) in U87+DBTRG and patient-derived gliomas. Immunohistochemistry was used to determine microvessel density [CD34], and cell proliferation [Ki67]. Western blot was used to assess the interleukin 17A [IL17A], vascular endothelial growth factor [VEGF] and hypoxia-inducible factor-1α [HIF-1α]. Antibody array was used to assess the cancer bio-markers in co-cultured U87+DBTRG gliomas. Animal survival was found to be significantly increased (P<0.0001) after FLVM treatment compared with control-IL17A. After FMT detection, FLVM, administered orally, was found to decrease tumor growth (P<0.0001). FLVM and FLVZ administration resulted in significant decreases in tumor hypoxia [HIF-1α (P<0.05)], angiogenesis [CD34 (P<0.05)], VEGF, IL17A and cell proliferation [Ki67 (P<0.05)] and caused a significant increase of Bax, caspase and FasL (P<0.05), compared with untreated animals. Additionally, Leptin, LPL (P<0.01), FFA (P<0.05) and adipogenesis were downregulated and no additive toxicity was found in mice except calorie-restriction like effect. Use of FLVM can be considered as a novel inhibitor of IL17A for the treatment of human gliomas.
Thyroid associated ophthalmopathy is an autoimmune disorder affecting the orbital and periorbital tissues. Hyperthyroidism is commonly associated with thyroid associated ophthalmopathy, however in 5% to 10% of cases it is euthyroid. Genetic, environmental and endogenous factors play a role in the initiation of the thyroid ophthalmopathy. Smoking has been identified as the strongest risk factor for the development of the disorder. The pathogenesis involves activation of both humoral and cell mediated immunity with subsequent production of gycoaminoglycans, hyaluronic acid resulting in oedema formation, increase extraocular mass and adipogenesis in the orbit. The natural history of the disease progresses from active to inactive fibrotic stage over a period of years. Diagnosis is mainly clinical and almost all patients with ophthalmopathy exhibit some form of thyroid abnormality on further testing. Treatment is based on the clinical severity of the disease. Non-severe cases are managed by supportive measures to reduce the symptomatology and severe cases are treated by either medical or surgical decompression. Rehabilitative surgery is done for quiescent disease to reduce diplopia and improve cosmesis.
In this study, the insulin-like and insulin sensitising effects of the ellagitannins geraniin, corilagin, ellagic acid, gallic acid and Nephelium lappaceum rind extract in 3T3-L1 adipocytes was investigated. It was observed that non-toxic concentrations of geraniin and its metabolites (0.2-20 μM) and N. lappaceum extract (0.2-20 μg/mL) exhibited insulin-like properties in the absence of insulin and insulin-sensitising properties in the presence of insulin particularly with regards to glucose uptake in 3T3-L1 adipocytes. The compounds were further able to promote adipocyte differentiation and may be involved in the inhibition of lipolysis in 3T3-L1 adipocytes in the presence of insulin. However further study into the molecular mechanisms of action of these compounds need to be carried out to better understand the potential of these compounds/extracts to act as therapeutic agents for hyperglycaemia associated with diabetes mellitus and obesity.
One of the advantages of human adipose-derived stem cells (ASCs) in regenerative medicine is that they can be harvested in abundance. However, the stemness biomarkers, which marked the safety and efficacy of ASCs in accordance with the good manufacturing practice guidelines, is not yet well established. This study was designed to investigate the effect of long-term culture on the stemness properties of ASCs using quantitative real-time polymerase chain reaction and flow cytometry. Results showed the growth rate of ASCs was at its peak when they reached P10 (population doubling; PD = 26) but started to decrease when they were expanded to P15 (PD = 36) and P20 (PD = 46). The ASCs can be culture expanded with minimal alteration in the stemness genes and cluster of differentiation (CD) markers expression up to P10. Expression level of Sox2, Nestin, and Nanog3 was significantly decreased at later passage. CD31, CD45, CD117, and human leukocyte antigen DR, DQ, and DP were lowly expressed at P5 and P10 but their expressions increased significantly at P15 or P20. The differentiation ability of ASCs (adipogenesis, osteogenesis, and neurogenesis) also decreased in long-term culture. Our findings suggested that P10 (PD = 26) should be the "cutoff point" for clinical usage because ASCs at passage 15 onward showed significant changes in the stemness genes, CD markers expression, and differentiation capability.
Obesity is a major risk factor for diabetes, and these two metabolic conditions cause significant healthcare burden worldwide. Chronic inflammation and increased oxidative stress due to exposure of cells to excess nutrients in obesity may trigger insulin resistance and pancreatic β-cell dysfunction. Tocotrienol, as a functional food component with anti-inflammatory, antioxidant, and cell signaling-mediating effects, may be a potential agent to complement the current management of obesity and diabetes. The review aimed to summarize the current evidence on the anti-obesity and antidiabetic effects of tocotrienol. Previous studies showed that tocotrienol could suppress adipogenesis and, subsequently, reduce body weight and fat mass in animals. This was achieved by regulating pathways of lipid metabolism and fatty acid biosynthesis. It could also reduce the expression of transcription factors regulating adipogenesis and increase apoptosis of adipocytes. In diabetic models, tocotrienol was shown to improve glucose homeostasis. Activation of peroxisome proliferator-activated receptors was suggested to be responsible for these effects. Tocotrienol also prevented multiple systemic complications due to obesity and diabetes in animal models through suppression of inflammation and oxidative stress. Several clinical trials have been conducted to validate the antidiabetic of tocotrienol, but the results were heterogeneous. There is no evidence showing the anti-obesity effects of tocotrienol in humans. Considering the limitations of the current studies, tocotrienol has the potential to be a functional food component to aid in the management of patients with obesity and diabetes.
Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand activated transcription factor, plays many essential roles of biological function in higher organisms. The PPARgamma is mainly expressed in adipose tissue. It regulates the transcriptional activity of genes by binding with other transcription factor. The PPARgamma coding region has been found to be closest to that of monkey in ours and other research groups. Thus, monkey is a more suitable animal model for future PPARgamma studying, although mice and rat are frequently being used. The PPARgamma is involved in regulating alterations of adipose tissue masses result from changes in mature adipocyte size and/or number through a complex interplay process called adipogenesis. However, the role of PPARgamma in negatively regulating the process of adipogenesis remains unclear. This review may help we investigate the differential expression of key transcription factor in adipose tissue in response to visceral obesity-induced diet in vivo. The study may also provide valuable information to define a more appropriate physiological condition in adipogenesis which may help to prevent diseases cause by negative regulation of the transcription factors in adipose tissue.
Kaempferol is a dietary bioflavonoid ubiquitously found in various types of plant. It possesses a wide range of medicinal properties suggesting its potential clinical utility that requires further investigation. The present review intends to highlight the efficacy of kaempferol and its molecular mechanisms of action in regulating bone metabolism. Many reports have acknowledged the bone-protecting property of kaempferol and kaempferol-containing plants using in vitro and in vivo experimental models. Kaempferol supplementation showed bone-sparing effects in newborn rats, glucocorticoid-induced and ovariectomy-induced osteoporotic models as well as bone fracture models. It achieves the bone-protective effects by inhibiting adipogenesis, inflammation, oxidative stress, osteoclastic autophagy and osteoblastic apoptosis while activating osteoblastic autophagy. The anti-osteoporotic effects of kaempferol are mediated through regulation of estrogen receptor, bone morphogenetic protein-2 (BMP-2), nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways. In summary, kaempferol exhibits beneficial effects on skeleton, thus is potentially effective for the prophylaxis and treatment of osteoporosis.
The insulin-like and/or insulin-sensitising effects of Syzygium aqueum leaf extract and its six bioactive compounds; 4-hydroxybenzaldehyde, myricetin-3-O-rhamnoside, europetin-3-O-rhamnoside, phloretin, myrigalone-G and myrigalone-B were investigated in 3T3-L1 adipocytes. We observed that, S. aqueum leaf extract (0.04-5 μg/ml) and its six bioactive compounds (0.08-10 μM) at non-cytotoxic concentrations were effectively enhance adipogenesis, stimulate glucose uptake and increase adiponectin secretion in 3T3-L1 adipocytes. Clearly, the compounds myricetin-3-O-rhamnoside and europetin-3-O-rhamnoside showed insulin-like and insulin-sensitising effects on adipocytes from a concentration of 0.08 μM. These compounds were far better than rosiglitazone and the other isolated compounds in enhancing adipogenesis, stimulating 2-NBDG uptake and increasing adiponectin secretion at all the concentrations tested. These suggest the antidiabetic potential of S. aqueum leaf extract and its six bioactive compounds. However, further molecular interaction studies to explain the mechanisms of action are highly warranted.
Unhealthy eating habits and lack of physical activities are among the contributing factors for obesity and diabetes. It has been reported that consumption of naturally occurring phenolics could exert beneficial effects toward these diseases. Therefore, this study aims to evaluate the ability of phenolic-rich soy husk powder extract (SHPE) in modifying the physical and biochemical parameters for obesity and diabetes. Forty-nine Sprague Dawley rats were divided into seven groups, including three supplementary/treatment groups. Rats in supplementary/treatment groups were provided with either 4 mg/kg BW Rosiglitazone Maleate, 250 mg SHPE/kg BW, or 500 mg SHPE/kg BW. The effectiveness of SHPE in alleviating obesity-diabetes was evaluated by measuring body weight (physical parameter), blood glucose metabolisms (biochemical parameters), and PPARγ expression. Findings in the present study revealed that short-term SHPE and Rosiglitazone Maleate administration improved the physical and biochemical parameters of obese-diabetic rats. In addition, SHPE was also demonstrated to upregulate PPARγ expression in adipocytes. These findings suggest that soy husk could emerge as a potential hypoglycemic and anti-adipogenic nutraceutical in future. PRACTICAL APPLICATIONS: This was the first study to evaluate the potential effects of soy husk against the parameters of obese-diabetes in rats. In addition, promising effects derived from this study might explore the possibility of soy husk to be utilized as an antidiabetes nutraceutical.
Adipocytes are major tissues involved in glucose uptake second to skeletal muscle and act as the main adipocytokines mediator that regulates glucose uptake mechanism and cellular differentiation. The objective of this study were to examine the effect of the SDF7, which is a fraction consists of four flavonoid compounds (quercetin: p-coumaric acid: luteolin: apigenin=8: 26: 1: 3) from Scoparia dulcis Linn., on stimulating the downstream components of insulin signalling and the adipocytokines expression on different cellular fractions of 3T3-F442a adipocytes.
Hyaluronan (HA), an extra-cellular matrix glycosaminoglycan, may play a role in mesenchymal stem cell differentiation to fat but results using murine models and cell lines are conflicting. Our previous data, illustrating decreased HA production during human adipogenesis, suggested an inhibitory role. We have investigated the role of HA in adipogenesis and fat accumulation using human primary subcutaneous preadipocyte/fibroblasts (PFs, n = 12) and subjects of varying body mass index (BMI). The impact of HA on peroxisome proliferator-activated receptor gamma (PPARγ) expression was analysed following siRNA knockdown or HA synthase (HAS)1 and HAS2 overexpression. PFs were cultured in complete or adipogenic medium (ADM) with/without 4-methylumbelliferone (4-MU = HA synthesis inhibitor). Adipogenesis was evaluated using oil red O (ORO), counting adipogenic foci, and measurement of a terminal differentiation marker. Modulating HA production by HAS2 knockdown or overexpression increased (16%, p < 0.04) or decreased (30%, p = 0.01) PPARγ transcripts respectively. The inhibition of HA by 4-MU significantly enhanced ADM-induced adipogenesis with 1.52 ± 0.18- (ORO), 4.09 ± 0.63- (foci) and 2.6 ± 0.21-(marker)-fold increases compared with the controls, also increased PPARγ protein expression (40%, (p < 0.04)). In human subjects, circulating HA correlated negatively with BMI and triglycerides (r = -0.396 (p = 0.002), r = -0.269 (p = 0.038), respectively), confirming an inhibitory role of HA in human adipogenesis. Thus, enhancing HA action may provide a therapeutic target in obesity.
Milk is a rich source of miRNA packaged in exosomes. Evidence for the systemic uptake and tissue distribution of milk exosomes was reported in newborn and adult humans and animals. Breastfeeding in infants was associated with a reduced risk of obesity. Numerous adipogenesis-related miRNAs have been detected in human milk exosomes. It has been demonstrated that ingested exosomal milk miRNAs may alter gene expression in offspring to regulate their metabolism and growth. In humans, consumption of other species' milk, such as cows and goats, is continued through adulthood. Since miRNAs are conserved, the concern of cross-species transfer of adipogenic miRNA has been raised in recent years, and the increase in obesity worldwide was attributed partially to dairy milk consumption by humans. However, evidence is still weak. Research emphasizes the need for an adequate number of exosomal milk's miRNAs to reach the target cell for biological action to be achieved. It was reported that obese women's milk had less miRNA-148a and miRNA-30b, which may affect the fat acquisition of their babies. Some exosomal milk miRNAs, such as miRNA-29, miRNA-148, miRNA-30b and miRNA-125b, may have epigenetic effects on milk recipients. Moreover, the ability of milk exosomes to cross the gastrointestinal barrier makes them a promising oral drug delivery tool. Yet, exosomes may also be tagged with specific ligands which target certain tissues. Thus, milk exosomes can be engineered and loaded with certain miRNAs responsible for adipocyte differentiation, conversion, or browning. Modifications in the miRNA cargo of exosomes can benefit human health and be an alternative to traditional drugs.
This study was to assess the impact of different colors of coffee fruit (green, yellow and red) on adipogenesis and/or lipolysis using 3T3-L1 adipocytes. Characterization of chemical constituents in different colors of coffee fruit extracts was determined by ESI-Q-TOF-MS. The cytotoxicity of the extracts in 3T3-L1 preadipocytes were evaluated by MTT assay. Oil-red O staining and amount of glycerol released in 3T3-L1 adipocytes were measured for lipid accumulation and lipolysis activity. All coffee fruit extracts displayed similar chromatographic profiles by chlorogenic acid > caffeoylquinic acid > caffeic acid. Different colors of raw coffee fruit possessed inhibitory adipogenesis activity in 3T3-L1 adipocytes, especially CRD decreased lipid accumulation approximately 47%. Furthermore, all extracts except CYF and their major compounds (malic, quinic, and chlorogenic acid) increased glycerol release. Our data suggest that different colors of coffee fruit extract have possessed anti-adipogenic and lipolytic properties and may contribute to the anti-obesity effects.
Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research.
Cryopreservation represents an effective technique to maintain the functional properties of human adipose-derived stem cells (ASCs) and allows pooling of cells via long-term storage for clinical applications, e.g., cell-based therapies. It is crucial to reduce freezing injury during the cryopreservation process by loading the ASCs with the optimum concentration of suitable cryoprotective agents (CPAs). In this study, human ASCs were preserved for 3 months in different combinations of CPAs, including 1) 0.25 M trehalose; 2) 5% dimethylsulfoxide (DMSO); 3) 10% DMSO; 4) 5% DMSO + 20% fetal bovine serum (FBS); 5) 10% DMSO + 20% FBS; 6) 10% DMSO + 90% FBS. Interestingly, even with a reduction of DMSO to 5% and without FBS, cryopreserved ASCs maintained high cell viability comparable with standard cryomedium (10% DMSO + 90% FBS), with normal cell phenotype and proliferation rate. Cryopreserved ASCs also maintained their differentiation capability (e.g., to adipocytes, osteocytes and chondrocytes) and showed an enhanced expression level of stemness markers (e.g., NANOG, OCT-4, SOX-2 and REX-1). Our findings suggest that 5% DMSO without FBS may be an ideal CPA for an efficient long-term cryopreservation of human ASCs. These results aid in establishing standardized xeno-free long-term cryopreservation of human ASCs for clinical applications.
Critical time windows exert profound influences on foetal physiological and metabolic profiles, which predispose an individual to later diseases via a 'programming' effect. Obesity has been suggested to be 'programmed' during early life. Foetuses and infants who experience adverse growth are subjected to a higher risk of obesity. However, the key factors that link adverse foetal growth and obesity risk remain obscure. To date, there is considerable evidence showing that the overall balance between free radical damage and the anti.oxidative process being challenged occurs throughout gestation. With the view that pregnancy is a pro-inflammatory state confronted with enhanced oxidative stress, which possesses similar characteristics to obesity (a chronic inflammatory state with increased oxidative stress), oxidative stress is thus biologically plausibly be proposed as the underlying mechanism between this causal-disease relationship. Oxidative stress could act as a programming cue for the development of obesity by inducing complex functional and metabolic deregulations as well as inducing the alteration of the adipogenesis process. Thereby, oxidative stress promotes adipose tissue deposition from early life onwards. The enhancement of fat accumulation further exaggerates oxidative derangement and perpetuates the cycle of adiposity. This review focuses on the oxidative stress pathways in prenatal and early postnatal stages, from the aspects of various endogenous and exogenous oxidative insults. Because oxidative stress is a modifiable pathway, this modifiability suggests a potential therapeutic target to fight the obesity epidemic by understanding the causal factors of oxidant induction.