Search Results (33)

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening vascular disease lacking therapies that target underlying cell death pathways. Ferroptosis, an iron-dependent form of lipid peroxidation-driven cell death, has emerged as a key mechanism in vascular remodeling. We investigated whether exogenous ketosis induced by ketone ester (KE) supplementation can suppress ferroptosis and prevent TAAD. TAAD was induced in C57BL/6 mice using β-aminopropionitrile (BAPN). A subset of these mice received KE [(R)-3-hydroxybutyl (R)-3-hydroxybutyrate, 20 g/L] in their drinking water starting on day 15 of the BAPN treatment. Human aortic smooth muscle cells (HASMCs) were treated with the GPX4 inhibitor Ras-Selective Lethal 3 (RSL3) and β-hydroxybutyrate (β-OHB) to investigate ferroptotic markers, lipid peroxidation, and labile iron levels. KE supplementation significantly reduced TAAD incidence (69% → 43%) and improved survival rate (52% → 73%), while preserving aortic structure and reducing elastic fiber fragmentation. Transcriptomic analyses of human TAAD datasets (GSE153434 and GSE52093) and single-cell RNA sequencing data (GSE155468) revealed ferroptosis signatures characterized by decreased GPX4 and increased expression of iron metabolism genes. Mechanistically, KE suppressed BAPN-induced iron accumulation and lipid peroxidation in vivo. In HASMCs, β-OHB inhibited ferroptosis induced by GPX4 inhibition, decreasing lipid peroxidation and labile iron levels. KE restored GPX4 and SLC7A11 expression while suppressing HO-1 in vivo, with effects dependent on Nrf2 signaling in vitro. In summary, ketone ester supplementation protects against TAAD by inhibiting VSMC ferroptosis via GPX4 induction and HO-1 suppression, highlighting a potential therapeutic strategy for aortic disease. Full article

Background/Objectives: The ketogenic diet (KD) has been shown to exert beneficial effects on human immunity by enhancing cytotoxic T lymphocyte function through metabolic reprogramming. However, strict dietary restrictions limit adherence and complicate its use in clinical practice. Exogenous ketone supplements have therefore been promoted as a more feasible alternative to elevate ketone body levels without the need for dietary changes. The objective of this study was to assess whether ketone salt or ketone ester supplementation can reproduce KD-mediated immunometabolic effects on CD8⁺ T cells in healthy individuals. Methods: In a prospective interventional study, healthy volunteers received either ketone salts (KS) or ketone esters (KE) for three weeks. Plasma β-hydroxybutyrate (BHB) concentrations were determined, and CD8⁺ T-cell cytokine secretion, functional responses, and mitochondrial energy metabolism were analyzed. In a subgroup, KS supplementation was combined with a carbohydrate-restricted, non-ketogenic diet. Results: While KS supplementation resulted in a short-lived increase in plasma BHB concentrations followed by increased BHB uptake in immune cells, KE supplementation led to more sustained plasma BHB levels, however, without detectable intracellular BHB accumulation. Neither intervention affected CD8⁺ T-cell cytokine production, functional capacity, or mitochondrial energy metabolism, and KS intake combined with a carbohydrate-restricted, non-ketogenic diet likewise did not alter CD8⁺ T-cell immunometabolic parameters. Conclusions: Transient elevation of circulating ketone body levels through supplementation seems insufficient to reproduce the immunometabolic effects of a KD, which likely require broader metabolic adaptations. Thus, the impact of exogenous ketones on adaptive immunity in healthy individuals appears limited. Full article

Multiple sclerosis (MS) is characterized by progressive mitochondrial dysfunction affecting complexes I, III, and IV of the electron transport chain, contributing to axonal energy failure and neurodegeneration. This review examines the potential of combining β-hydroxybutyrate (βHB), epigallocatechin-3-gallate (EGCG), and ellagic acid (EA) as a multi-target therapeutic strategy to restore mitochondrial function in patients with MS. Experimental and clinical studies demonstrate that each compound exerts complementary mechanisms. Ketone bodies provide an alternative energy substrate and restore complex I activity via sirtuin-dependent pathways. EGCG acts predominantly at the peripheral level by reducing systemic inflammation and oxidative stress. EA-derived urolithins effectively cross the blood–brain barrier to directly enhance mitochondrial biogenesis and respiratory chain function in the central nervous system. Clinical trials have reported improvements in fatigue, cognition, mood, and muscle function following supplementation with these compounds. The convergence of their actions on energy restoration, reactive oxygen species reduction, and epigenetic modulation of protective pathways suggests their synergistic potential. Optimized delivery strategies, including exogenous ketone salts, liposomal EGCG, and microencapsulated EA, may overcome bioavailability limitations and interindividual variability in the gut microbiota metabolism. Full article

Background: Neonatal hypoxic–ischemic encephalopathy remains a leading cause of neonatal mortality and long-term neurodevelopmental disability worldwide. Despite the widespread adoption of therapeutic hypothermia, a substantial proportion of affected infants experience death or significant neurological impairment. Given their metabolic vulnerability, ketogenic diet strategies and ketone bodies have emerged as potential adjunctive neuroprotective interventions. This scoping review aims to critically evaluate the mechanistic rationale, preclinical evidence, and clinical feasibility of ketogenic approaches. Methods: A scoping review of the literature was conducted, including experimental and clinical studies investigating ketogenic diets, endogenous ketosis, and exogenous ketone supplementation in neonatal hypoxia–ischemia. Evidence was synthesized across mechanistic, preclinical, nutritional, and clinical domains, with particular attention to developmental context, timing of intervention, safety considerations, and translational relevance in the contest of therapeutic hypothermia. Results: Preclinical studies consistently demonstrate that ketone bodies enhance cerebral energy metabolism, support mitochondrial function, reduce excitotoxic signaling, and attenuate oxidative stress and neuroinflammation in the immature brain. Neonatal models show preferential utilization of β-hydroxybutyrate over glucose during hypoxic–ischemic stress, suggesting intrinsic metabolic advantages. Emerging evidence also supports potential long-term effects on epigenetic regulation and white matter development, although direct causal validation in neonatal HIE remains limited. Nutritional studies indicate that carefully monitored enteral and parenteral feeding is feasible in critically ill neonates, identifying a potential window for metabolic interventions. Conclusions: Ketogenic strategies represent a plausible, multimodal approach to targeting the metabolic and inflammatory sequelae of neonatal HIE. While current evidence is insufficient to support clinical implementation, this scoping review provides a hypothesis-generating framework to guide future translational research and the design of carefully controlled clinical trials in neonatal neurocritical care. Full article

Ketone metabolism is currently being spotlighted for its health benefits. Strict dietary carbohydrate restriction is required to increase plasma ketone levels, which can be achieved with D-β-hydroxybutyric acid (D-BHB) supplementation as well. Although 2.9 g/day of D-BHB may reduce body fat without dieting or exercise interventions, the lower effective intake limit of exogenous D-BHB remains unknown. In this randomized, double-blind, placebo-controlled study (UMIN000054231), we aimed to assess the safety and fat-reduction effects of a 12-week intake of D-BHB in healthy Japanese adults (low-dose [1.5 g/day, n = 33], normal-dose [2.9 g/day, n = 33], and placebo [n = 34] groups). Blood samples were collected pre- and post-intervention. Participants’ blood chemistry, anthropometric, and body composition parameters were investigated. The low-dose group had a lower visceral fat area and body mass index (BMI) and higher plasma ketone levels than the placebo group. The normal-dose group had a significantly lower visceral fat area than the placebo group. Significant between-group (normal-dose vs. placebo) differences were observed in body weight, BMI, body fat percentage, fat mass, and plasma ketone levels. Participants reported no D-BHB-related adverse effects or discomfort. In conclusion, 1.5 or 2.9 g/day of D-BHB may reduce body fat without dieting or exercise interventions. Full article

Background/Objectives: Exogenous ketone supplements elevate circulating ketones without carbohydrate restriction, but their long-term hepatic safety remains unclear. This study evaluated the formulation-dependent impact of chronic ketone supplementation on liver histopathology, inflammatory signaling, and systemic biomarkers in rats. Methods: Male Sprague-Dawley rats were orally administered 1,3-butanediol (BD), medium-chain triglycerides (MCTs), ketone ester (KE), ketone electrolytes/salts (KSs), or a ketone salt–MCT combination (KSMCT) for 4 weeks. In a separate arm, animals received standard diet (SD), or SD supplemented with low-dose KE (LKE) or high-dose KE (HKE), for 83 days. Liver structure was assessed by hematoxylin and eosin staining with quantification of red blood cell density and lipid accumulation. Inflammatory and metabolic responses were evaluated by TNF-α and arginase immunohistochemistry. Serum biochemistry included glucose, proteins, electrolytes, and liver and kidney function markers. Results: BD and KE induced macrovesicular steatosis, vascular congestion, and elevated TNF-α and arginase expression, consistent with hepatic stress. MCT caused moderate hepatocellular ballooning and lipid deposition, whereas KS preserved near-normal hepatic morphology. KSMCT produced intermediate effects, reducing lipid accumulation and TNF-α compared with MCT or KE alone. KE supplementation caused dose-dependent reductions in globulin and elevations in creatinine, while HKE reduced sodium and glucose levels. Conclusions: Chronic hepatic responses to exogenous ketones are highly formulation dependent. KS demonstrated the most favorable safety profile under the tested conditions, maintaining normal hepatic structure, while BD and KE elicited adverse changes. Formulation choice is critical for the safe long-term use of exogenous ketones. Full article

Neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis, are characterized by progressive neuronal loss and share key pathological features such as oxidative stress, mitochondrial dysfunction, and chronic neuroinflammation. Recent research has highlighted the potential of ketogenic metabolism, particularly the use of ketone bodies like β-hydroxybutyrate, as a therapeutic approach targeting these shared mechanisms. This review provides a comprehensive synthesis of current knowledge on the neuroprotective effects of ketogenic interventions, including both dietary strategies and exogenous ketone supplementation. We discuss how ketone bodies improve mitochondrial function, reduce reactive oxygen species, modulate inflammatory pathways, and influence neurotransmission and synaptic plasticity. Additionally, we examine experimental and clinical evidence supporting the application of ketogenic therapies in neurodegenerative diseases, highlighting disease-specific findings, benefits, and limitations. While preclinical data are robust and suggest meaningful therapeutic potential, clinical studies remain limited and heterogeneous, with challenges related to adherence, safety, and patient selection. The review also addresses the translational relevance of ketogenic strategies, considering their feasibility, combination with other therapies, and the need for personalized approaches based on genetic and metabolic profiles. By critically evaluating existing data, this article aims to clarify the mechanisms through which ketogenic metabolism may exert neuroprotective effects and to outline future directions for research and clinical application in the context of neurodegenerative disorders. Full article

Ketone bodies (KBs), particularly β-hydroxybutyrate, are crucial metabolites that provide clean and efficient energy, especially during periods of low glucose availability. Ketogenesis is a promising therapeutic avenue for conditions such as obesity, metabolic syndrome, and diabetes. This review aims to summarize the current evidence on ketogenesis across different health conditions and therapeutic modalities, highlighting the potential to mitigate metabolic disorders and diabetes-related complications. By reducing inflammation and oxidative stress, increased KB production provides cardiovascular and neuroprotective benefits. Ketogenesis is enhanced under physiological conditions like pregnancy and fasting, as well as in pathophysiological states such as diabetes and heart failure. Various interventions, including the promotion of endogenous ketogenesis through diet and exercise, drug-induced ketogenesis via sodium-glucose cotransporter 2 inhibitors, and exogenous ketone supplementation, have demonstrated favorable effects on metabolic health. However, challenges remain, including risks such as pathological ketoacidosis and dyslipidemia. In specific populations, such as lean mass hyper-responders, laboratory lipid profiles might reflect the metabolic privilege. This review will assist in the future clarification of individual differences and optimized therapeutic approaches leveraging ketogenesis for the personalized management of metabolic disorders. Full article

Background: It has been demonstrated that levetiracetam can decrease absence epileptic activity in both human patients and different types of animal models of absence epilepsy, such as the genetically absence epileptic Wistar Albino Glaxo/Rijswijk (WAG/Rij) rat. It was also suggested previously that exogenous ketone supplements (EKSs)-evoked ketosis not only decreases the number of spike-wave discharges (SWDs) but also enhances the anti-absence epileptic effect of pyrimidine nucleoside uridine in WAG/Rij rats. These findings suggest that EKSs may enhance the efficacy of clinically used anti-epileptic drugs, such as levetiracetam. Methods: We investigated the effect of not only levetiracetam (intraperitoneal/i.p. 200 mg/kg) alone and KEKS supplemented food (containing 10% ketone ester/KE and 10% ketone salt/KS in a normal rat chow) alone, but also the combination of levetiracetam and KEKS supplemented food on SWD number and SWD time for 5 days in WAG/Rij rats. For evaluation of SWDs, electroencephalographic (EEG) recordings were performed every day. Moreover, for the measurement of blood glucose and R-beta-hydroxybutyrate (R-βHB) levels, the blood was taken from the tail vein of rats after EEG registration. Results: It was demonstrated that the administration of both levetiracetam alone and KEKS food alone decreased the SWD number and time spent in SWD, compared to control. Moreover, after combined administration of levetiracetam with KEKS food, enhanced anti-absence epileptic effect was observed, compared to levetiracetam alone. Blood R-βHB level significantly increased after administration of both KEKS food alone and KEKS food in combination with levetiracetam. Nevertheless, these treatments did not significantly change the blood glucose levels. Conclusions: We can conclude that EKSs may be able to enhance the anti-epileptic effect of different drugs, and this combined treatment method may represent a promising new approach and effective therapy against epileptic seizures, especially in treatment-resistant patients. Full article

Ketone bodies (KBs) serve as an alternative energy source for healthy and failing hearts and have important effects on myocardial blood perfusion in both physiological and pathological states. Early animal studies suggest that KBs may provide protective benefits in ischemic heart disease and heart failure. Under normal circumstances, coronary blood flow regulation is an intricate system with contributions from metabolic, autonomic, compressive, and endothelial factors, with the metabolic regulatory pathway being the most significant contributor. We conducted a non-systematic review of studies published between 1987 and 2024. In this review, we explored the physiological autoregulation of normal coronary blood flow, the role of ketone bodies in myocardial perfusion in health and disease, and the potential role of exogenous ketone body supplementation in producing salutary effects on myocardial blood flow (MBF) and metabolism in exercise and cardiac disease states including ischemia, heart failure, and the aging heart. Overall, our findings demonstrated that KBs improve MBF and ejection fraction in healthy human subjects and have beneficial effects on cardiac output and left heart filling pressures in patients with decompensated heart failure. Although resting myocardial blood flow decreases with age, further studies are required to assess the impact of KBs on MBF in aging populations. Additionally, more research is needed to investigate the effects of KBs during exercise and in instances of myocardial ischemia. Full article

Background/Objectives: Ketone salt (KS) containing a racemic beta-hydroxybutyrate mixture is commonly used as an alternative fuel source as it may lead to improved health and/or performance. We postulate that KS will raise acetoacetate levels and represent the effectiveness of exogenous KS as an energy source. We conducted a pilot study to quantify changes in the circulating acetoacetate following KS and to determine if any changes in acetoacetate were associated with the changes in circulating beta-hydroxybutyrate. Methods: Thirteen adults (21.6 ± 4.3 years old; seven males/six females) completed this randomized, triple-blinded, placebo-controlled, cross-over design study. Participants consumed either KS or flavor-matched placebo with a one-week washout period between supplements. Blood samples were taken before and 30 min after consuming each supplement, and plasma acetoacetate and beta-hydroxybutyrate levels were measured by gas chromatography/mass spectrometry. Results: The consumption of KS resulted in a significant increase in acetoacetate from baseline. The increase in acetoacetate after the KS supplement was significantly greater than that following the consumption of a placebo (↑ 0.57 ± 0.44 mM vs. ↑ 0.07 ± 0.23 mM, p = 0.009, d = 0.86), and significantly and strongly related to the change in blood beta-hydroxybutyrate (r = 0.757, p < 0.001). Conclusions: Our findings indicate that KS markedly increases plasma ketone body interconversion, presumably to supply peripheral tissues for ATP generation. Full article

Ketone bodies are molecules produced from fatty acids in the liver that act as energy carriers to peripheral tissues when glucose levels are low. Carbohydrate- and calorie-restricted diets, known to increase the levels of circulating ketone bodies, have attracted significant attention in recent years due to their potential health benefits in several diseases. Specifically, increasing ketones through dietary modulation has been reported to be beneficial for cardiovascular health and to improve glucose homeostasis and insulin resistance. Interestingly, although excessive production of ketones may lead to life-threatening ketoacidosis in diabetic patients, mounting evidence suggests that modest levels of ketones play adaptive and beneficial roles in pancreatic beta cells, although the exact mechanisms are still unknown. Of note, Sodium-Glucose Transporter 2 (SGLT2) inhibitors have been shown to increase the levels of beta-hydroxybutyrate (BHB), the most abundant ketone circulating in the human body, which may play a pivotal role in mediating some of their protective effects in cardiovascular health and diabetes. This systematic review provides a comprehensive overview of the scientific literature and presents an analysis of the effects of ketone bodies on cardiovascular pathophysiology and pancreatic beta cell function. The evidence from both preclinical and clinical studies indicates that exogenous ketones may have significant beneficial effects on both cardiomyocytes and pancreatic beta cells, making them intriguing candidates for potential cardioprotective therapies and to preserve beta cell function in patients with diabetes. Full article

Background: Ketone body supplementation has emerged as a potential ergogenic aid in cycling. Exogenous ketones, primarily in the form of beta-hydroxybutyrate, offer an alternative fuel source, bypassing the need for strict ketogenic diets. However, the science surrounding their efficacy remains complex, with mixed field findings and unexplored mechanisms. Methods: A narrative review of the current literature was conducted, synthesizing studies on the metabolic and cognitive effects of ketone bodies in cycling. The review included an examination of human and mechanistic studies, along with emerging hypotheses on ketone bodies and their role in modulating red blood cell production and recovery processes. Results: Ketone body supplementation can theoretically spare glycogen, reduce muscle protein breakdown, enhance fat oxidation, and improve recovery by mitigating oxidative stress and inflammation. Additionally, ketone bodies may support cognitive function, reducing perceived mental fatigue. Preliminary evidence also suggests a potential role in modulating erythropoietin levels through histone acetylation, though further research is needed to establish its impact on oxygen delivery. Despite the theoretical potential, the practical assessment of field studies shows disappointing effects on performance from ketone body supplementation. Conclusions: While ketone bodies offer several potential benefits for cyclists, the variability in individual responses, lack of long-term data, and inconsistent findings in performance studies highlight the need for further research. Optimizing dosage, timing, and understanding the broader implications of ketone body supplementation will be crucial for their practical application in cycling. Full article

Background/Objectives: Elevating ketone levels with therapeutic nutritional ketosis can help to metabolically manage disease processes associated with epilepsy, diabetes, obesity, cancer, and neurodegenerative disease. Nutritional ketosis can be achieved with various dieting strategies such as the classical ketogenic diet, the modified Atkins diet, caloric restriction, periodic fasting, or the consumption of exogenous ketogenic supplements such as medium-chain triglycerides (MCTs). However, these various strategies can be unpleasant and difficult to follow, so that achieving and sustaining nutritional ketosis can be a major challenge. Thus, investigators continue to explore the science and applications of exogenous ketone supplementation as a means to further augment the therapeutic efficacy of this metabolic therapy. Methods: Here, we describe a structurally new synthetic triglyceride, glycerol tri-acetoacetate (Gly-3AcAc), that we prepared from glycerol and an acetoacetate precursor that produces hyperketonemia in the therapeutic range (2–3 mM) when administered to mice under both fasting and non-fasting conditions. Animal studies were undertaken to evaluate the potential effects of eliciting a ketogenic response systemically. Acute effects (24 h or less) were determined in male VM/Dk mice in both fasted and unfasted dietary states. Results: Concentration levels of β-hydroxybutyrate in blood were elevated (βHB; 2–3 mM) under both conditions. Levels of glucose were reduced only in the fasted state. No detrimental side effects were observed. Conclusions: Pending further study, this novel compound could potentially add to the repertoire of methods for inducing therapeutic nutritional ketosis. Full article

Background/Objectives: Ketone esters (KEs) exhibit promise as anti-cancer agents but their impact on spontaneous metastases remains poorly understood. Although consumption of a ketogenic diet (KD) that is low in carbohydrates and high in fats can lead to KE production in vivo, the restrictive composition of KDs may diminish adherence in cancer patients. Methods: We investigated the effects of an exogenous ketone ester-supplemented (eKET), carbohydrate-replete diet on tumor growth, metastasis, and underlying mechanisms in orthotopic models of metastatic breast (4T1-Luc) and renal (Renca-Luc) carcinomas. Mice were randomized to diet after tumor challenge. Results: Administration of KEs did not alter tumor cell growth in vitro. However, in mice, our eKET diet increased circulating β-hydroxybutyrate and inhibited primary tumor growth and lung metastasis in both models. Body composition analysis illustrated the overall safety of eKET diet use, although it was associated with a loss of fat mass in mice with renal tumors. Immunogenetic profiling revealed divergent intratumoral eKET-related changes by tumor type. In mammary tumors, Wnt and TGFβ pathways were downregulated, whereas in renal tumors, genes related to hypoxia and DNA damage repair were downregulated. Conclusions: Thus, our eKET diet exerts potent antitumor and antimetastatic effects in both breast and renal cancer models, albeit with different modes of action and physiologic effects. Its potential as an adjuvant dietary approach for patients with diverse cancer types should be explored further. Full article