Glucose-lowering effects of a synbiotic combination containing Pediococcus acidilactici in C. elegans and mice.

AIMS/HYPOTHESIS: Modulation of gut microbiota has emerged as a promising strategy to treat or prevent the development of different metabolic diseases, including type 2 diabetes and obesity. Previous data from our group suggest that the strain Pediococcus acidilactici CECT9879 (pA1c) could be an effective probiotic for regulating glucose metabolism. Hence, the objectives of this study were to verify the effectiveness of pA1c on glycaemic regulation in diet-induced obese mice and to evaluate whether the combination of pA1c with other normoglycaemic ingredients, such as chromium picolinate (PC) and oat ß-glucans (BGC), could increase the efficacy of this probiotic on the regulation of glucose and lipid metabolism. METHODS: Caenorhabditis elegans was used as a screening model to describe the potential synbiotic activities, together with the underlying mechanisms of action. In addition, 4-week-old male C57BL/6J mice were fed with a high-fat/high-sucrose diet (HFS) for 6 weeks to induce hyperglycaemia and obesity. Mice were then divided into eight groups (n=12 mice/group) according to dietary supplementation: control-diet group; HFS group; pA1c group (1010 colony-forming units/day); PC; BGC; pA1c+PC+BGC; pA1c+PC; and pA1c+BGC. Supplementations were maintained for 10 weeks. Fasting blood glucose was determined and an IPGTT was performed prior to euthanasia. Fat depots, liver and other organs were weighed, and serum biochemical variables were analysed. Gene expression analyses were conducted by real-time quantitative PCR. Sequencing of the V3-V4 region of the 16S rRNA gene from faecal samples of each group was performed, and differential abundance for family, genera and species was analysed by ALDEx2R package. RESULTS: Supplementation with the synbiotic (pA1c+PC+BGC) counteracted the effect of the high glucose by modulating the insulin-IGF-1 signalling pathway in C. elegans, through the reversal of the glucose nuclear localisation of daf-16. In diet-induced obese mice, all groups supplemented with the probiotic significantly ameliorated glucose tolerance after an IPGTT, demonstrating the glycaemia-regulating effect of pA1c. Further, mice supplemented with pA1c+PC+BGC exhibited lower fasting blood glucose, a reduced proportion of visceral adiposity and a higher proportion of muscle tissue, together with an improvement in the brown adipose tissue in comparison with the HFS group. Besides, the effect of the HFS diet on steatosis and liver damage was normalised by the synbiotic. Gene expression analyses demonstrated that the synbiotic activity was mediated not only by modulation of the insulin-IGF-1 signalling pathway, through the overexpression of GLUT-1 and GLUT-4 mediators, but also by a decreased expression of proinflammatory cytokines such as monocyte chemotactic protein-1. 16S metagenomics demonstrated that the synbiotic combinations allowed an increase in the concentration of P. acidilactici, together with improvements in the intestinal microbiota such as a reduction in Prevotella and an increase in Akkermansia muciniphila. CONCLUSIONS/INTERPRETATION: Our data suggest that the combination of pA1c with PC and BGC could be a potential synbiotic for blood glucose regulation and may help to fight insulin resistance, diabetes and obesity.

Phenolic Compounds Inhibit 3T3-L1 Adipogenesis Depending on the Stage of Differentiation and Their Binding Affinity to PPARγ.

Phenolic compounds might modulate adiposity. Here, we report our observation that polyphenols and phenolic acids inhibit adipogenesis in 3T3-L1 with different intensity depending on the family and the stage of differentiation. While quercetin and resveratrol inhibited lipid accumulation along the whole process of differentiation, apigenin and myricetin were active during the early and latest stages, but not intermediate, contrary to hesperidin. The activity of phenolic acids was limited to the early stages of the differentiation process, except p-coumaric and ellagic acids. This anti-adipogenic effect was accompanied by down-regulation of Scd1 and Lpl. Molecular docking analysis revealed that the inhibitory activity of these phenolic compounds over the early stages of adipogenesis exhibits a significant correlation (r = 0.7034; p = 0.005) with their binding affinity to the ligand-binding domain of PPARγ. Results show that polyphenols and phenolic acids would interact with specific residues of the receptor, which could determine their potential anti-adipogenic activity during the early stages of the differentiation. Residues Phe264, His266, Ile281, Cys285 and Met348 are the most frequently involved in these interactions, which might suggest a crucial role for these amino acids modulating the activity of the receptor. These data contribute to elucidate the possible mechanisms of phenolic compounds in the control of adipogenesis.

Maresin 1 inhibits TNF-alpha-induced lipolysis and autophagy in 3T3-L1 adipocytes.

Obesity is associated with high levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), which promotes inflammation in adipose tissue. The omega-3 PUFAs, and their derived lipid mediators, such as Maresin 1 (MaR1) have anti-inflammatory effects on adipose tissue. This study aimed to analyze if MaR1 may counteract alterations induced by TNF-α on lipolysis and autophagy in mature 3T3-L1 adipocytes. Our data revealed that MaR1 (1-100 nM) inhibited the TNF-α-induced glycerol release after 48 hr, which may be related to MaR1 ability of preventing the decrease in lipid droplet-coating protein perilipin and G0/G1 Switch 2 protein expression. MaR1 also reversed the decrease in total hormone sensitive lipase (total HSL), and the ratio of phosphoHSL at Ser-565/total HSL, while preventing the increased ratio of phosphoHSL at Ser-660/total HSL and phosphorylation of extracellular signal-regulated kinase 1/2 induced by TNF-α. Moreover, MaR1 counteracted the cytokine-induced decrease of p62 protein, a key autophagy indicator, and also prevented the induction of LC3II/LC3I, an important autophagosome formation marker. Current data suggest that MaR1 may ameliorate TNF-α-induced alterations on lipolysis and autophagy in adipocytes. This may also contribute to the beneficial actions of MaR1 on adipose tissue and insulin sensitivity in obesity.

Role of cardiotrophin-1 in the regulation of metabolic circadian rhythms and adipose core clock genes in mice and characterization of 24-h circulating CT-1 profiles in normal-weight and overweight/obese subjects.

Cardiotrophin (CT)-1 is a regulator of glucose and lipid homeostasis. In the present study, we analyzed whether CT-1 also acts to peripherally regulate metabolic rhythms and adipose tissue core clock genes in mice. Moreover, the circadian pattern of plasma CT-1 levels was evaluated in normal-weight and overweight subjects. The circadian rhythmicity of oxygen consumption rate (Vo2) was disrupted in aged obese CT-1-deficient (CT-1-/-) mice (12 mo). Although circadian rhythms of Vo2 were conserved in young lean CT-1-/- mice (2 mo), CT-1 deficiency caused a phase shift of the acrophase. Most of the clock genes studied (Clock, Bmal1, and Per2) displayed a circadian rhythm in adipose tissue of both wild-type (WT) and CT-1-/- mice. However, the pattern was altered in CT-1-/- mice toward a lower percentage of the rhythm or lower amplitude, especially for Bmal1 and Clock. Moreover, CT-1 mRNA levels in adipose tissue showed significant circadian fluctuations in young WT mice. In humans, CT-1 plasma profile exhibited a 24-h circadian rhythm in normal-weight but not in overweight subjects. The 24-h pattern of CT-1 was characterized by a pronounced increase during the night (from 02:00 to 08:00). These observations suggest a potential role for CT-1 in the regulation of metabolic circadian rhythms.-López-Yoldi, M., Stanhope, K. L., Garaulet, M., Chen, X. G., Marcos-Gómez, B., Carrasco-Benso, M. P., Santa Maria, E. M., Escoté, X., Lee, V., Nunez, M. V., Medici, V., Martínez-Ansó, E., Sáinz, N., Huerta, A. E., Laiglesia, L. M., Prieto, J., Martínez, J. A., Bustos, M., Havel, P. J., Moreno-Aliaga, M. J. Role of cardiotrophin-1 in the regulation of metabolic circadian rhythms and adipose core clock genes in mice and characterization of 24-h circulating CT-1 profiles in normal-weight and overweight/obese subjects.

Effects of alpha-lipoic acid on chemerin secretion in 3T3-L1 and human adipocytes.

Chemerin is a novel adipokine associated with obesity and insulin resistance. α-Lipoic acid (α-LA) has shown beneficial properties on diabetes and obesity. The aim of this study was to examine the effects of α-LA on chemerin production in adipocytes in absence or presence of TNF-α, insulin and AICAR. The potential signaling pathways involved in α-LA effects on chemerin were also analyzed. α-LA actions on chemerin were tested in differentiated 3T3-L1 adipocytes and in some cases in human subcutaneous and omental adipocytes. Chemerin mRNA levels were measured by RT-PCR and the amount of chemerin secreted to culture media was determined by ELISA. α-LA induced a concentration-dependent inhibition on both chemerin secretion and mRNA levels in 3T3-L1 adipocytes. The AMPK activator AICAR and the PI3K inhibitor LY294002 dramatically abrogated both chemerin secretion and gene expression, and further potentiated the inhibitory effect of α-LA on chemerin secretion. Insulin was able to partially reverse the inhibitory action of α-LA on chemerin secretion. α-LA also reduced basal chemerin secretion in both subcutaneous and omental adipocytes from overweight/obese subjects. Moreover, α-LA was able to abolish the stimulatory effects of the pro-inflammatory cytokine TNF-α on chemerin secretion. Our data demonstrated the ability of α-LA to inhibit chemerin production, an adipokine associated to obesity and metabolic syndrome, suggesting that the reduction of chemerin could contribute to the antiobesity/antidiabetic properties described for α-LA.

Cardiotrophin-1 Regulates Adipokine Production in 3T3-L1 Adipocytes and Adipose Tissue From Obese Mice.

Cardiotrophin-1 (CT-1) belongs to the IL-6 family of cytokines. Previous studies of our group revealed that CT-1 is a key regulator of glucose and lipid metabolism. The aim of the present study was to analyze the in vitro and in vivo effects of CT-1 on the production of several adipokines involved in body weight regulation, nutrient metabolism, and inflammation. For this purpose, 3T3-L1 adipocytes were incubated with recombinant protein CT-1 (rCT-1) (1-40 ng/ml) for 1 and 18 h. Moreover, the acute effects of rCT-1 administration (0.2 mg/kg, i.v.) for 30 min and 3 h on adipokines levels were also evaluated in high-fat fed obese mice. In 3T3-L1 adipocytes, rCT-1 treatment downregulated the expression and secretion of leptin, resistin, and visfatin. However, rCT-1 significantly stimulated apelin mRNA and secretion. rCT-1 (18 h) also promoted the activation by phosphorylation of AKT, ERK 1/2, and STAT3. Interestingly, pre-treatment with the PI3K inhibitor LY294002 reversed the stimulatory effects of rCT-1 on apelin expression, suggesting that this pathway could be mediating the effects of rCT-1 on apelin production. In contrast, acute administration of rCT-1 (30 min and 3 h) to diet-induced obese mice downregulated leptin and resistin, without significantly modifying apelin or visfatin mRNA in adipose tissue. Furthermore, CT-1 null mice exhibited altered expression of adipokines in adipose tissue. The present study demonstrates that rCT-1 modulates the production of adipokines in vitro and in vivo, suggesting that the regulation of the secretory function of adipocytes could be involved in the metabolic actions of this cytokine. J. Cell. Physiol. 232: 2469-2477, 2017. © 2016 Wiley Periodicals, Inc.

Role of Omentin, Vaspin, Cardiotrophin-1, TWEAK and NOV/CCN3 in Obesity and Diabetes Development.

Adipose tissue releases bioactive mediators called adipokines. This review focuses on the effects of omentin, vaspin, cardiotrophin-1, Tumor necrosis factor-like Weak Inducer of Apoptosis (TWEAK) and nephroblastoma overexpressed (NOV/CCN3) on obesity and diabetes. Omentin is produced by the stromal-vascular fraction of visceral adipose tissue. Obesity reduces omentin serum concentrations and adipose tissue secretion in adults and adolescents. This adipokine regulates insulin sensitivity, but its clinical relevance has to be confirmed. Vaspin is produced by visceral and subcutaneous adipose tissues. Vaspin levels are higher in obese subjects, as well as in subjects showing insulin resistance or type 2 diabetes. Cardiotrophin-1 is an adipokine with a similar structure as cytokines from interleukin-6 family. There is some controversy regarding the regulation of cardiotrophin-1 levels in obese -subjects, but gene expression levels of cardiotrophin-1 are down-regulated in white adipose tissue from diet-induced obese mice. It also shows anti-obesity and hypoglycemic properties. TWEAK is a potential regulator of the low-grade chronic inflammation characteristic of obesity. TWEAK levels seem not to be directly related to adiposity, and metabolic factors play a critical role in its regulation. Finally, a strong correlation has been found between plasma NOV/CCN3 concentration and fat mass. This adipokine improves insulin actions.

Cardiotrophin-1 stimulates lipolysis through the regulation of main adipose tissue lipases.

Cardiotrophin-1 (CT-1) is a cytokine with antiobesity properties and with a role in lipid metabolism regulation and adipose tissue function. The aim of this study was to analyze the molecular mechanisms involved in the lipolytic actions of CT-1 in adipocytes. Recombinant CT-1 (rCT-1) effects on the main proteins and signaling pathways involved in the regulation of lipolysis were evaluated in 3T3-L1 adipocytes and in mice. rCT-1 treatment stimulated basal glycerol release in a concentration- and time-dependent manner in 3T3-L1 adipocytes. rCT-1 (20 ng/ml for 24 h) raised cAMP levels, and in parallel increased protein kinase (PK)A-mediated phosphorylation of perilipin and hormone sensitive lipase (HSL) at Ser660. siRNA knock-down of HSL or PKA, as well as pretreatment with the PKA inhibitor H89, blunted the CT-1-induced lipolysis, suggesting that the lipolytic action of CT-1 in adipocytes is mainly mediated by activation of HSL through the PKA pathway. In ob/ob mice, acute rCT-1 treatment also promoted PKA-mediated phosphorylation of perilipin and HSL at Ser660 and Ser563, and increased adipose triglyceride lipase (desnutrin) content in adipose tissue. These results showed that the ability of CT-1 to regulate the activity of the main lipases underlies the lipolytic action of this cytokine in vitro and in vivo, and could contribute to CT-1 antiobesity effects.

Pediococcus acidilactici (pA1c®) alleviates obesity-related dyslipidemia and inflammation in Wistar rats by activating beta-oxidation and modulating the gut microbiota.

Due to the importance of the gut microbiota in the regulation of energy homeostasis, probiotics have emerged as an alternative therapy to ameliorate obesity-related disturbances, including cholesterol metabolism dysregulation, dyslipidemia and inflammation. Therefore, the objectives of this study were to evaluate the effect of the probiotic strain Pediococcus acidilactici (pA1c®) on the regulation of adiposity, cholesterol and lipid metabolism, inflammatory markers and gut microbiota composition in diet-induced obese rats. Twenty-nine four-week-old male Wistar rats were divided into three groups: rats fed a control diet (CNT group, n = 8), rats fed a high fat/high sucrose diet (HFS group, n = 11), and rats fed a HFS diet supplemented with pA1c® (pA1c®group, n = 10). Organs and fat depots were weighed, and different biochemical parameters were analysed in serum. Gene expression analyses in the adipose tissue were conducted using real-time quantitative-PCR. Faecal microbiota composition was evaluated using 16S metagenomics. Animals supplemented with pA1c® exhibited a lower proportion of visceral adiposity, a higher proportion of muscle, an improvement in the total-cholesterol/HDL-cholesterol ratio and a decrease in the total cholesterol, triglyceride and aspartate aminotransaminase (AST) serum levels, together with a decrease in several inflammation-related molecules. The expression of key genes related to adipose (Adipoq, Cebpa and Pparg) and glucose (Slc2a1 and Slc2a4) metabolism in the adipose tissue was normalized by pA1c®. Moreover, it was demonstrated that pA1c® supplementation activated fatty acid ß-oxidation in the adipose tissue and the liver. Metagenomics demonstrated the presence of pA1c® in the faecal samples, an increase in alpha diversity, an increase in the abundance of beneficial bacteria, and a decrease in the abundance of harmful micro-organisms, including the Streptococcus genus. Thus, our data suggest the potential of pA1c® in the prevention of obesity-related disturbances including hypercholesterolemia, hypertriglyceridemia, inflammation and gut microbiota dysbiosis.

Association of the Gut Microbiota with the Host's Health through an Analysis of Biochemical Markers, Dietary Estimation, and Microbial Composition.

This study aims to analyze the relationship between gut microbiota composition and health parameters through specific biochemical markers and food consumption patterns in the Spanish population. This research includes 60 Spanish adults aged 47.3 ± 11.2 years old. Biochemical and anthropometric measurements, and a self-referred dietary survey (food frequency questionnaire), were analyzed and compared with the participant´s gut microbiota composition analyzed by 16s rDNA sequencing. Several bacterial strains differed significantly with the biochemical markers analyzed, suggesting an involvement in the participant´s metabolic health. Lower levels of Lactobacillaceae and Oscillospiraceae and an increase in Pasteurellaceae, Phascolarctobacterium, and Haemophilus were observed in individuals with higher AST levels. Higher levels of the Christensenellaceae and a decrease in Peptococcaceae were associated with higher levels of HDL-c. High levels of Phascolarctobacterium and Peptococcus and low levels of Butyricicoccus were found in individuals with higher insulin levels. This study also identified associations between bacteria and specific food groups, such as an increase in lactic acid bacteria with the consumption of fermented dairy products or an increase in Verrucomicrobiaceae with the consumption of olive oil. In conclusion, this study reinforces the idea that specific food groups can favorably modulate gut microbiota composition and have an impact on host´s health.

Phenolic Compounds Reduce the Fat Content in Caenorhabditis elegans by Affecting Lipogenesis, Lipolysis, and Different Stress Responses.

Supplementation with bioactive compounds capable of regulating energy homeostasis is a promising strategy to manage obesity. Here, we have screened the ability of different phenolic compounds (myricetin, kaempferol, naringin, hesperidin, apigenin, luteolin, resveratrol, curcumin, and epicatechin) and phenolic acids (p-coumaric, ellagic, ferulic, gallic, and vanillic acids) regulating C. elegans fat accumulation. Resveratrol exhibited the strongest lipid-reducing activity, which was accompanied by the improvement of lifespan, oxidative stress, and aging, without affecting worm development. Whole-genome expression microarrays demonstrated that resveratrol affected fat mobilization, fatty acid metabolism, and unfolded protein response of the endoplasmic reticulum (UPRER), mimicking the response to calorie restriction. Apigenin induced the oxidative stress response and lipid mobilization, while vanillic acid affected the unfolded-protein response in ER. In summary, our data demonstrates that phenolic compounds exert a lipid-reducing activity in C. elegans through different biological processes and signaling pathways, including those related with lipid mobilization and fatty acid metabolism, oxidative stress, aging, and UPR-ER response. These findings open the door to the possibility of combining them in order to achieve complementary activity against obesity-related disorders.

A combination of borage seed oil and quercetin reduces fat accumulation and improves insulin sensitivity in obese rats.

The metabolic properties of omega-6 fatty acid consumption are being increasingly accepted. We had previously observed that supplementation with a borage seed oil (BSO), as a source of linoleic (18:2n-6; LA) and gamma-linolenic (18:3n-6; GLA) acids, reduces body weight and visceral adiposity and improves insulin sensitivity in a diet-induced obesity model of Wistar rats. Here, it was investigated whether the anti-obesogenic properties of BSO could be maintained in a pre-obese model of rats, and if these effects are enhanced by a combination with low doses of quercetin, together with its potential role in the regulation of the adipocyte biology. The combination of BSO and quercetin during 8 weeks was able to ameliorate glucose intolerance and insulin resistance, and to improve liver steatosis. Although no effects were observed on body weight, animals supplemented with this combination exhibited a lower proportion of visceral adiposity. In addition, in vitro differentiation of epididymal adipose-precursor cells of the BSO-treated animals exhibited a down-regulation of Fasn, Glut4, Pparg and Srebp1 genes, in comparison with the control group. Finally, in vitro evaluation of the components of BSO demonstrated that the anti-adipogenic activity of quercetin was significantly potentiated by the combination with both LA and GLA through the down-regulation of different adipogenesis-key genes in 3T3-L1 cells. All these data suggest that omega-6 fatty acids LA and GLA, and their natural sources such as BSO, could be combined with quercetin to potentiate their effects in the prevention of the excess of adiposity and the insulin resistance.

Low doses of cocoa extract supplementation ameliorate diet-induced obesity and insulin resistance in rats.

Cocoa polyphenols exhibit high antioxidant activity and have been proposed as a potential adjuvant for the treatment of metabolic disturbances. Here, we demonstrate that supplementation with low doses (14 and 140 mg per kg per rat) of a complete cocoa extract induces metabolic benefits in a diet-induced obesity (DIO) model of Wistar rats. After 10 weeks, cocoa extract-supplemented animals exhibited significantly lower body weight gain and food efficiency, with no differences in energy intake. Cocoa significantly reduced visceral (epididymal and retroperitoneal) and subcutaneous fat accumulation accompanied by a significant reduction in the adipocyte size, which was mediated by downregulation of the adipocyte-specific genes Cebpa, Fasn and Adipoq. Additionally, cocoa extract supplementation reduced the triacylglycerol/high density lipoprotein (TAG/HDL) ratio, decreased hepatic triglyceride accumulation, improved insulin sensitivity by reducing HOMA-IR, and significantly ameliorated glucose tolerance after an intraperitoneal glucose tolerance test. Finally, no adverse effect was observed in an in vivo toxicity evaluation of our cocoa extract at doses up to 500 mg kg-1 day-1. Our data demonstrate that low doses of cocoa extract supplementation (14 and 140 mg kg-1 day-1) are safe and sufficient to counteract obesity and type-2 diabetes in rats and provide new insights into the potential application of cocoa supplements in the management of the metabolic syndrome.

Borago officinalis seed oil (BSO), a natural source of omega-6 fatty acids, attenuates fat accumulation by activating peroxisomal beta-oxidation both in C. elegans and in diet-induced obese rats.

Obesity is a medical condition with increasing prevalence, characterized by an accumulation of excess fat that could be improved using some bioactive compounds. However, many of these compounds with in vitro activity fail to respond in vivo, probably due to the sophistication of the physiological energy regulatory networks. In this context, C. elegans has emerged as a plausible model for the identification and characterization of the effect of such compounds on fat storage in a complete organism. However, the results obtained in such a simple model are not easily extrapolated to more complex organisms such as mammals, which hinders its application in the short term. Therefore, it is necessary to obtain new experimental data about the evolutionary conservation of the mechanisms of fat loss between worms and mammals. Previously, we found that some omega-6 fatty acids promote fat loss in C. elegans by up-regulation of peroxisomal fatty acid ß-oxidation in an omega-3 independent manner. In this work, we prove that the omega-6 fatty acids' effects on worms are also seen when they are supplemented with a natural omega-6 source (borage seed oil, BSO). Additionally, we explore the anti-obesity effects of two doses of BSO in a diet-induced obesity rat model, validating the up-regulation of peroxisomal fatty acid ß-oxidation. The supplementation with BSO significantly reduces body weight gain and energy efficiency and prevents white adipose tissue accumulation without affecting food intake. Moreover, BSO also increases serum HDL-cholesterol levels, improves insulin resistance and promotes the down-regulation of Cebpa, an adipogenesis-related gene. Therefore, we conclude that the effects of omega-6 fatty acids are highly conserved between worms and obesity-induced mammals, so these compounds could be considered to treat or prevent obesity-related disorders.

Cardiotrophin-1: A multifaceted cytokine.

Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines that have pleiotropic functions on different tissues and cell types. Although many effects of CT-1 have been described on the heart, there is an extensive research showing important protective effects in other organs such as liver, kidney or nervous system. Recently, several studies have pointed out that CT-1 might also play a key role in the regulation of body weight and intermediate metabolism. This paper will review many aspects of CT-1 physiological role in several organs and discuss data for consideration in therapeutic approaches.

α-lipoic acid reduces fatty acid esterification and lipogenesis in adipocytes from overweight/obese subjects.

OBJECTIVE: α-Lipoic acid (α-LA) is a natural occurring antioxidant with beneficial effects on obesity. The aim of this study was to investigate the putative effects of α-LA on triglyceride accumulation and lipogenesis in subcutaneous adipocytes from overweight/obese subjects and to determine the potential mechanisms involved. METHODS: Fully differentiated human subcutaneous adipocytes were treated with α-LA (100 and 250 µM) during 24 h for studying triglyceride content, de novo lipogenesis, and levels of key lipogenic enzymes. The involvement of AMP-activated protein kinase (AMPK) activation was also evaluated. RESULTS: α-LA down-regulated triglyceride content by inhibiting fatty acid esterification and de novo lipogenesis. These effects were mediated by reduction in fatty acid synthase (FAS), stearoyl-coenzyme A desaturase 1, and diacylglycerol O-acyltransferase 1 protein levels. Interestingly, α-LA increased AMPK and acetyl CoA carboxylase phosphorylation, while the presence of the AMPK inhibitor Compound C reversed the inhibition observed on FAS protein levels. CONCLUSIONS: α-LA down-regulates key lipogenic enzymes, inhibiting lipogenesis and reducing triglyceride accumulation through the activation of AMPK signaling pathway in human subcutaneous adipocytes from overweight/obese subjects.