Search Results (297)

Circadian rhythms are intrinsic 24 h cycles that regulate metabolic processes across multiple tissues, with skeletal muscle emerging as a central node in this temporal network. Muscle clocks govern gene expression, fuel utilisation, mitochondrial function, and insulin sensitivity, thereby maintaining systemic energy homeostasis. However, circadian misalignment, whether due to behavioural disruption, nutrient excess, or metabolic disease, impairs these rhythms and contributes to insulin resistance, and the development of obesity, and type 2 diabetes mellitus. Notably, the muscle clock remains responsive to non-photic cues, particularly exercise, which can reset and amplify circadian rhythms even in metabolically impaired states. This work synthesises multi-level evidence from rodent models, human trials, and in vitro studies to elucidate the role of skeletal muscle clocks in circadian metabolic health. It explores how exercise entrains the muscle clock via molecular pathways involving AMPK, SIRT1, and PGC-1α, and highlights the time-of-day dependency of these effects. Emerging data demonstrate that optimally timed exercise enhances glucose uptake, mitochondrial biogenesis, and circadian gene expression more effectively than time-agnostic training, especially in individuals with metabolic dysfunction. Finally, findings are integrated from multi-omic approaches that have uncovered dynamic, time-dependent molecular signatures that underpin circadian regulation and its disruption in obesity. These technologies are uncovering biomarkers and signalling nodes that may inform personalised, temporally targeted interventions. By combining mechanistic insights with translational implications, this review positions skeletal muscle clocks as both regulators and therapeutic targets in metabolic disease. It offers a conceptual framework for chrono-exercise strategies and highlights the promise of multi-omics in developing precision chrono-medicine approaches aimed at restoring circadian alignment and improving metabolic health outcomes. Full article

Insulin-regulated glucose uptake is a central mechanism in maintaining systemic glucose homeostasis, primarily occurring in skeletal muscle and adipose tissue. This process relies on the insulin-stimulated translocation of the glucose transporter, GLUT4, from specialized intracellular compartments, known as GLUT4 storage vesicles (GSVs), to the plasma membrane. Disruption of this pathway is a hallmark of insulin resistance and a key contributor to the pathogenesis of type 2 diabetes. Recent advances have provided critical insights into both the insulin signalling cascades and the complex biogenesis, as well as the trafficking and fusion dynamics of GSVs. This review synthesizes the current understanding of the molecular mechanisms governing GSV mobilization and membrane fusion, highlighting key regulatory nodes that may become dysfunctional in metabolic disease. By elucidating these pathways, we propose new therapeutic avenues targeting GSV trafficking to improve insulin sensitivity and combat type 2 diabetes. Full article

Type 2 diabetes (T2D) is a prevalent metabolic disorder characterized by persistent hyperglycemia, hyperinsulinemia, and long-term cardiovascular complications. Another hallmark of T2D is disrupted hormonal homeostasis—marked by elevated levels of insulin and leptin and reduced adiponectin—which plays a crucial role in modulating immune cell function. Individuals with T2D exhibit a skewed immune profile, with an elevated secretion of pro-inflammatory cytokines such as IFN-γ, TNF-α, IL17, and IL6, which are well-established drivers of vascular inflammation and dysfunction. Moreover, dysregulated metabolic hormones in T2D promote the acquisition of a pro-inflammatory phenotype in immune cells, suggesting that these hormones not only regulate energy balance but also serve as potent immune activators. Their dysregulation likely plays a significant—and perhaps underappreciated—role in the onset and progression of diabetic cardiovascular complications. Full article

Obesity remains a major global health challenge with limited therapeutic options. Bromelain, a proteolytic enzyme complex derived from pineapple, has been recognized for its natural anti-inflammatory, anti-edematous, and appetite-suppressing properties. This study aimed to investigate the effects of bromelain on hypothalamic neuropeptides and metabolic markers in a high-fat diet (HFD)-induced obesity model in rats. Thirty-six male Wistar albino rats were randomly divided into four groups: standard diet (SD), standard diet with bromelain (SDBro), high-fat diet (HFD), and high-fat diet with bromelain (HFDBro). Obesity was induced by a 3-month HFD regimen, followed by bromelain supplementation (200 mg/kg/day, orally) for one month. Hypothalamic tissues were analyzed via ELISA for neuropeptide Y (NPY), pro-opiomelanocortin (POMC), glucose transporter 2 (GLUT2), fibroblast growth factor 2 (FGF2), and insulin-like growth factor 1 receptor (IGF1R). While NPY levels showed no significant changes, POMC increased in the HFD and was normalized with bromelain. GLUT2 was downregulated in the HFD and significantly restored by bromelain. FGF2 levels remained unchanged. IGF1R was upregulated in the HFD but reduced by bromelain, with an unexpected increase in SDBro. Overall, bromelain partially reversed HFD-induced disruptions in hypothalamic energy-regulating pathways, particularly affecting GLUT2 and POMC. These findings highlight bromelain’s potential role in central metabolic regulation under dietary stress. Full article

Lipopolysaccharide (LPS), the defining outer membrane component of Gram-negative bacteria, is a potent immunostimulant recognized by Toll-like receptor 4 (TLR4). While extensively studied for its roles in immune activation and barrier disruption, the potential function of LPS as a developmental cue remains largely unexplored. By leveraging Caenorhabditis elegans and its genetic and gnotobiotic advantages, we screened a panel of Escherichia coli LPS biosynthesis mutants. This screen revealed that the loss of outer core glycosylation in the ∆rfaG mutant causes significant developmental delay independent of bacterial metabolism. Animals exhibited developmental delay that was rescued by exogenous LPS or amino acid supplementation, implicating that LPS triggers nutrient-sensing signaling. Mechanistically, this developmental arrest was mediated by the host FOXO transcription factor DAF-16, which is the key effector of insulin/IGF-1 signaling (IIS). Our findings uncover an unprecedented role for microbial LPS as a critical regulator of host development, mediated through conserved host IIS pathways, fundamentally expanding our understanding of host–microbe crosstalk. Full article

Cinnamic acid, an organic acid naturally occurring in plants of the Cinnamomum genus, has been highly valued for its medicinal properties in numerous ancient Chinese texts. This article reviews the chemical composition, pharmacological effects, and various applications of cinnamic acid and its derivatives reported in publications from 2016 to 2025, and anticipates their potential in medical and industrial fields. This review evaluates studies in major scientific databases, including Web of Science, PubMed, and ScienceDirect, to ensure a comprehensive analysis of the therapeutic potential of cinnamic acid. Through systematic integration of existing knowledge, it has been revealed that cinnamic acid has a wide range of pharmacological activities, including anti-tumor, antibacterial, anti-inflammatory, antidepressant and hypoglycemic effects. Additionally, it has been shown to be effective against a variety of pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, and foodborne Pseudomonas. Cinnamic acid acts by disrupting cell membranes, inhibiting ATPase activity, and preventing biofilm formation, thereby demonstrating its ability to act as a natural antimicrobial agent. Its anti-inflammatory properties are demonstrated by improving oxidative stress and reducing inflammatory cell infiltration. Furthermore, cinnamic acid enhances metabolic health by improving glucose uptake and insulin sensitivity, showing promising results in improving metabolic health in patients with diabetes and its complications. This systematic approach highlights the need for further investigation of the mechanisms and safety of cinnamic acid to substantiate its use as a basis for new drug development. Particularly in the context of increasing antibiotic resistance and the search for sustainable, effective medical treatments, the study of cinnamic acid is notably significant and innovative. Full article

Modern life, characterized by constant exposure to artificial light from electronic devices, such as light-emitting diodes (LEDs), disrupts the natural circadian rhythm and induces important metabolic changes. The impact of blue light exposure on male and female rat’s onset of puberty, hormonal and biochemical parameters was assessed by comparison between the four study groups: the control group (CTRL) maintained under normal light conditions, the group exposed to blue light from a mobile phone (MP), the group subjected to blue light from a computer screen (PC), and the group exposed to blue light from an LED lamp (LED). Both female and male rats exposed to PC and LED failed to thrive, with a significantly lower body weight intake than the CTRL group. All three distinct sources of blue light interfered with the cyclicity of the estrous cycle in female rats. A marked decrease in the number of complete estrous cycles and the highest incidence of incomplete cycles were noticed in the LED group. Elevated ALT, AST, glucose, and insulin levels were influenced in a gender-specific manner, and depending on the source of emitted light. Prolonged blue light exposure induces significant metabolic disruptions and possesses important future research potential in identifying explicit pathways regarding this environmental stressor. Full article

Background: The most common female endocrinopathy is polycystic ovary syndrome (PCOS), affecting 10–20% of women of reproductive age. It is associated with a wide range of hormonal and biochemical abnormalities and long-term metabolic and cardiovascular risks. It is characterized by infertility due to chronic anovulation, hyperandrogenism, polycystic ovarian morphology, and is often associated with insulin resistance (IR) and obesity. Hyperinsulinemia further increases androgen production and reduces sex hormone-binding globulin (SHBG) levels, thereby aggravating symptoms. In addition, vitamin D deficiency is often present in PCOS patients, and increasing evidence suggests that it may also be associated with insulin resistance and hyperandrogenism. Objective: This study aimed to evaluate the relationships between insulin resistance, vitamin D deficiency, body mass index (BMI), and androgen levels in women with PCOS. Method: A cross-sectional study was conducted in which data from 195 women diagnosed with PCOS and not yet receiving therapy at a gynecologic endocrinology unit of a university-based tertiary clinical center, between 2019 and 2024, were analyzed. The parameters recorded were age, body mass index (BMI), 25(OH) vitamin D levels, androgen hormone levels (testosterone, androstenedione), glucose-insulin responses during a 3-point oral glucose tolerance test (OGTT). Statistical analyses, including linear regression, Pearson, and Spearman correlation tests were used to assess associations between variables. Results: The mean age of the patients was 24.8 years (18–42), and the mean BMI was 30.6 kg/m² (17–51). Vitamin D deficiency was observed in 84.1% of patients, hyperandrogenism in 45.8%, and insulin resistance in 44.5%. A significant inverse correlation was found between BMI and vitamin D levels (r = −0.31, p =< 0.01) indicating that higher BMI is associated with lower vitamin D status. Similarly, BMI also showed a significant negative correlation with SHBG levels (r = –0.45, p < 0.01), suggesting that increasing body weight is linked to reduced SHBG concentrations. In addition, BMI was significantly positively correlated with 2 h insulin levels (r = 0.43, p =< 0.01) and with testosterone levels (r = 0.21, p = 0.01). These findings suggest that increased adiposity intensifies insulin resistance and is linked to both vitamin D deficiency and elevated androgen levels. Moreover, the combination of hyperinsulinemia and low vitamin D further disrupts hormonal balance by promoting ovarian androgen production and decreasing SHBG levels, thereby increasing the bioavailability of testosterone. A significant inverse correlation was found between vitamin D levels and 2 h insulin levels (r = −0.28, p =< 0.01), indicating that lower vitamin D status is associated with increased insulin resistance. Furthermore, 2 h insulin levels showed a significant positive correlation with testosterone levels (r = 0.32, p =< 0.01), suggesting that greater insulin resistance is linked to higher androgen production. Additionally, vitamin D levels were inversely correlated with testosterone (r = −0.18, p = 0.02), demonstrating that a lower vitamin D status may further contribute to the hyperandrogenic environment. Vitamin D levels also showed a significant positive correlation with SHBG concentrations (r = 0.29, p < 0.01), indicating that a higher vitamin D status may be associated with increased SHBG levels. In contrast, 2 h insulin levels were inversely correlated with SHBG (r = −0.43, p < 0.01), reflecting the suppressive effect of hyperinsulinemia on SHBG production. Conclusions: Insulin resistance, BMI, and vitamin D deficiency are closely related to each other and to the severity of PCOS, which is confirmed by the correlations with androgen levels. The revealed relationships draw attention to the special importance of vitamin D supplementation and the correction of carbohydrate metabolism in alleviating the symptoms of the disease and reducing long-term health risks. Full article

Lipedema is a chronic, estrogen-sensitive adipose tissue disorder characterized by disproportionate subcutaneous fat accumulation, fibrosis, inflammation, and resistance to fat mobilization. Despite its high prevalence, lipedema remains poorly understood and frequently misdiagnosed. This narrative review proposes a novel pathophysiological model in which menopause acts as a critical turning point in the progression of lipedema, driven by estrogen receptor imbalance (ERβ predominance over ERα), intracrine estrogen excess, and adipose tissue dysfunction. We demonstrate how menopause amplifies adipose tissue dysfunction by suppressing ERα signaling; enhancing ERβ activity; and disrupting mitochondrial function, insulin sensitivity, and lipid oxidation. Concurrently, the upregulation of aromatase and 17β-HSD1, combined with the suppression of 17β-HSD2, sustains localized estradiol excess, perpetuating inflammation, fibrosis, and immune dysregulation. The molecular signature observed in lipedema closely mirrors that of other estrogen-driven gynecological disorders, such as endometriosis, adenomyosis, and uterine fibroids. Understanding these molecular mechanisms highlights the pivotal role of menopause as a catalyst for disease progression and provides a rationale for targeted therapeutic strategies, including hormonal modulation and metabolic interventions. This review reframes lipedema as an estrogen receptor-driven gynecological disorder, offering a new perspective to improve clinical recognition, diagnosis, and management of this neglected condition. Full article

Lipid hormone imbalances involving glucocorticoids, thyroid hormones (THs), and sex hormones have widespread metabolic consequences, contributing to the global increase in obesity and insulin resistance. This review examines the complex role of disrupted lipid hormone pathways in the development of metabolic disorders, particularly metabolic dysfunction-associated steatotic liver disease (MASLD). Endocrine disorders such as hypercortisolism, hypothyroidism, and polycystic ovary syndrome (PCOS) are closely linked to MASLD through shared metabolic pathways. Mechanisms include glucocorticoid-induced gluconeogenesis and lipolysis, impaired lipid clearance in hypothyroidism, and the hyperandrogenism-induced downregulation of hepatic low-density lipoprotein (LDL) receptors. PCOS-related factors—such as central obesity, adipocyte hypertrophy, low adiponectin levels, and genetic predisposition—further promote hepatic steatosis. Thyroid dysfunction may also impair the hepatic deiodination of T4, contributing to lipid accumulation and inflammation. Given the overlapping pathophysiology among endocrine, hepatic, and reproductive disorders, multidisciplinary collaboration is essential to optimize diagnosis, treatment, and long-term cardiometabolic outcomes. Full article

This study evaluated the effects of dietary supplementation with omega-3 polyunsaturated fatty acids from extruded linseed, alone and combined with Padina pavonica algae extract, on growth performance and metabolic status in fattening rabbits. Sixty New Zealand White rabbits were assigned to three groups, as follows: control (CNT), L (5% linseed), and LPP (3.5% linseed + 0.2% algae extract) from weaning (37 days) to slaughter (85 days). Productive performance was assessed through body weight (BW), average daily gain (ADG), feed conversion ratio (FCR), and feed intake (FI). Blood was sampled at weaning, 60 days, and slaughter and analyzed for insulin, leptin, cortisol, thyroid hormones (T3, T4), glucose, and non-esterified fatty acids (NEFAs). The L group showed significantly higher ADG (41.0 ± 1 g/d) and improved FCR (4.1 ± 0.2) compared to LPP (ADG: 37 ± 1 g/d, FCR: 4.6 ± 0.2; p = 0.001). No differences were observed in final BW or FI among groups (p < 0.001). Insulin peaked at 60 days across all groups (p < 0.001), with the LPP group showing the lowest levels (9.8 ± 0.9 µUI/mL; p = 0.043). T3 and T4 increased significantly with age (p < 0.001), and the T3/T4 ratio varied by diet and time (p = 0.005). Cortisol rose only at slaughter (p < 0.001) and negatively correlated with insulin and thyroid hormones. The results suggest that omega-3-rich nutraceuticals can enhance growth performance without disrupting metabolic balance and may modulate specific hormonal responses due to their bioactive compounds. Full article

In placental mammals, the co-option of vertebrate orthologous ATP1B4 genes has profoundly altered the properties of the encoded BetaM proteins, which function as bona fide β-subunits of Na,K-ATPases in lower vertebrates. Eutherian BetaM acquired an extended Glu-rich N-terminal domain resulting in the complete loss of its ancestral function and became a skeletal and cardiac muscle-specific component of the inner nuclear membrane. BetaM is expressed at the highest level during perinatal development and is implicated in gene regulation. Here we report the long-term consequences of Atp1b4 ablation on metabolic parameters in adult mice. Male BetaM-deficient (Atp1b4−/Y) mice have remarkably lower body weight and adiposity than their wild-type littermates, despite higher food intake. Indirect calorimetry shows higher energy expenditure (heat production and oxygen consumption) with a greater spontaneous locomotor activity in Atp1b4−/Y males. Their lower respiratory exchange ratio suggests a greater reliance on fat metabolism compared to their wild-type counterparts. Consistently, Atp1b4−/Y KO mice exhibit enhanced β-oxidation in skeletal muscle, along with improved glucose and insulin tolerance. These robust metabolic changes induced by Atp1b4 disruption demonstrate that eutherian BetaM plays an important role in regulating adult mouse metabolism. This demonstrates that bypassing the co-option of Atp1b4 potentially reduces susceptibility to obesity. Thus, Atp1b4 ablation leading to the loss of evolutionarily acquired BetaM functions serves as a model for a potential alternative pathway in mammalian evolution. Full article

Obesity-driven inflammation disrupts gut barrier integrity and promotes inflammatory bowel disease (IBD). Emerging evidence highlights gut hormones—including glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2), glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), cholecystokinin (CCK), and apolipoprotein A4 (APOA4)—as key regulators of metabolism and mucosal immunity. This review outlines known mechanisms and explores therapeutic prospects in IBD. GLP-1 improves glycemic control, induces weight loss, and preserves intestinal barrier function, while GLP-2 enhances epithelial repair and reduces pro-inflammatory cytokine expression in animal models of colitis. GIP facilitates lipid clearance, enhances insulin sensitivity, and limits systemic inflammation. PYY and CCK slow gastric emptying, suppress appetite, and attenuate colonic inflammation via neural pathways. APOA4 regulates lipid transport, increases energy expenditure, and exerts antioxidant and anti-inflammatory effects that alleviate experimental colitis. Synergistic interactions—such as GLP-1/PYY co-administration, PYY-stimulated APOA4 production, and APOA4-enhanced CCK activity—suggest that multi-hormone combinations may offer amplified therapeutic benefits. While preclinical data are promising, clinical evidence supporting gut hormone therapies in IBD remains limited. Dual GIP/GLP-1 receptor agonists improve metabolic and inflammatory parameters, but in clinical use, they are associated with gastrointestinal side effects that warrant further investigation. Future research should evaluate combination therapies in preclinical IBD models, elucidate shared neural and receptor-mediated pathways, and define optimal strategies for applying gut hormone synergy in human IBD. These efforts may uncover safer, metabolically tailored treatments for IBD, particularly in patients with coexisting obesity or metabolic dysfunction. Full article

The gut microbiome is vital in maintaining metabolic health, and dietary habits can significantly impact its composition. A high-fat diet (HFD) can disrupt gut microbial balance, contributing to obesity, insulin resistance, and fatty liver disease. This study explores the potential benefits of heat-killed Enterococcus faecalis EF-2001 (EF-2001) in restoring gut balance and improving metabolic health in HFD-fed mice (HFD-mice). HFD mice administered EF-2001 had 18% less body fat, 22% lower triglyceride levels, and significantly reduced liver enzyme markers, including aspartate aminotransferase (AST) by 28% and alanine aminotransferase (ALT) by 31%. Additionally, EF-2001 improved glucose metabolism, increasing glucose tolerance by 20% and insulin sensitivity by 15%, while reducing fat buildup in the liver by 24%, indicating protection against fatty liver disease. These changes correlated with better metabolic health and reduced inflammation. Our results show that EF-2001 supplementation helped counteract HFD-induced gut imbalances by increasing microbial diversity and supporting beneficial bacteria, such as Akkermansia and Ligilactobacillus spp. Our findings highlight the potential of heat-killed EF-2001 as a promising strategy to restore gut balance and mitigate diet-related metabolic issues. Furthermore, analysis of antibiotic resistance genes (ARGs) revealed that HFD mice exhibited an increased abundance of multidrug resistance genes, particularly those associated with antibiotic efflux mechanisms, such as bcrA, cdeA, and msbA. Notably, EF-2001 supplementation mitigated this increase, reducing the relative abundance of the above ARGs and suggesting a protective role in limiting the spread of antibiotic resistance linked to dysbiosis. EF-2001 offers a compelling approach to managing obesity and metabolic disorders, paving the way for microbiome-based health interventions. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental condition frequently associated with gastrointestinal symptoms, gut dysbiosis, and metabolic dysfunctions such as insulin resistance (IR). Recent evidence suggests that the gut microbiota may influence both metabolic and neurological processes through the gut–brain–metabolic axis. This review explores the molecular mechanisms linking dysbiosis, IR, and ASD, focusing on pathways such as TLR/NF-κB activation, PI3K/Akt/mTOR disruption, and the action of microbial metabolites, like short-chain fatty acids (SCFAs), lipopolysaccharide (LPS), and γ-aminobutyric acid (GABA). We discuss how dysbiosis may contribute to increased intestinal permeability, systemic inflammation, and neuroimmune activation, ultimately affecting brain development and behavior. Common microbial alterations in ASD and IR—including increased Clostridium, Desulfovibrio, and Alistipes, and reduced Bifidobacterium and butyrate-producing genera—suggest a shared pathophysiology. We also highlight potential therapeutic strategies, such as microbiota modulation, insulin-like growth factor 1 (IGF-1) treatment, and dietary interventions. Understanding these interconnected mechanisms may support the development of microbiota-targeted approaches for individuals with ASD metabolic comorbidities. Full article