BHB, when used as a dietary supplement (i.e., an exogenous ketone), complements insulin therapy in providing cellular energy to neurons by serving as an alternative substrate for ATP production, especially under conditions of reduced glucose availability or impaired glucose utilization.
BHB crosses the blood-brain barrier and is metabolized in neuronal mitochondria to acetyl-CoA, entering the tricarboxylic acid (TCA) cycle and supporting oxidative phosphorylation, thereby sustaining neuronal ATP levels and complimenting insulin's role in supporting cellular energy.[11-16]
This complementary mechanism is particularly relevant in settings where neuronal energy is compromised, such as in glaucoma. BHB preserves mitochondrial bioenergetics, reduces oxidative stress, and prevents neuronal apoptosis during glucose deprivation, thereby maintaining neuronal viability and function.[12-13][15][17] Additionally, BHB modulates key signaling pathways (e.g., AMPK, SIRT2, p38 MAPK) that enhance mitochondrial quality control, autophagy, and resistance to energy stress, further supporting neuronal health in the context of compromised cellular energy.[18][17]
In summary, BHB supplementation provides a parallel energy source to glucose, ensuring continuous neuronal energy supply and neuroprotection, particularly in neurodegenerative conditions such as glaucoma.[11-17]
References:
Falkenhain K, Islam H, Little JP.
Experimental Physiology. 2023;108(2):177-187. doi:10.1113/EP090430.
Bharmal SH, Cho J, Alarcon Ramos GC, et al.
The Journal of Nutrition. 2021;151(4):921-929. doi:10.1093/jn/nxaa417.
Background: The potential of a ketone monoester (β-hydroxybutyrate; KEβHB) supplement to rapidly mimic a state of nutritional ketosis offers a new therapeutic possibility for diabetes prevention and management. While KEβHB supplementation has a glucose-lowering effect in adults with obesity, its impact on glucose control in other insulin-resistant states is unknown.
Objectives: The primary objective was to investigate the effect of KEβHB-supplemented drink on plasma glucose in adults with prediabetes. The secondary objective was to determine its impact on plasma glucoregulatory peptides.
Methods: This randomized controlled trial [called CETUS (Cross-over randomizEd Trial of β-hydroxybUtyrate in prediabeteS)] included 18 adults [67% men, mean age = 55 y, mean BMI (kg/m2) = 28.4] with prediabetes (glycated hemoglobin between 5.7% and 6.4% and/or fasting plasma glucose between 100 and 125 mg/dL). Participants were randomly assigned to receive KEβHB-supplemented and placebo drinks in a crossover sequence (washout period of 7-10 d between the drinks). Blood samples were collected from 0 to 150 min, at intervals of 30 min. Paired-samples t tests were used to investigate the change in the outcome variables [β-hydroxybutyrate (βHB), glucose, and glucoregulatory peptides] after both drinks. Repeated measures analyses were conducted to determine the change in concentrations of the prespecified outcomes over time.
Results: Blood βHB concentrations increased to 3.5 mmol/L within 30 minutes after KEβHB supplementation. Plasma glucose AUC was significantly lower after KEβHB supplementation than after the placebo [mean difference (95% CI): -59 (-85.3, -32.3) mmol/L × min]. Compared with the placebo, KEβHB supplementation led to significantly greater AUCs for plasma insulin [0.237 (0.044, 0.429) nmol/L × min], C-peptide [0.259 (0.114, 0.403) nmol/L × min], and glucose-dependent insulinotropic peptide [0.243 (0.085, 0.401) nmol/L × min], with no significant differences in the AUCs for amylin, glucagon, and glucagon-like peptide 1.
Conclusions: Ingestion of the KEβHB-supplemented drink acutely increased the blood βHB concentrations and lowered the plasma glucose concentrations in adults with prediabetes. Further research is needed to investigate the dynamics of repeated ingestions of a KEβHB supplement by individuals with prediabetes, with a view to preventing new-onset diabetes. This trial was registered at www.clinicaltrials.gov as NCT03889210.
Walsh JJ, Caldwell HG, Neudorf H, Ainslie PN, Little JP.
The Journal of Physiology. 2021;599(21):4763-4778. doi:10.1113/JP281988.
Adults with obesity are at increased risk of neurocognitive impairments, partly as a result of reduced cerebral blood flow and brain-derived neurotrophic factor (BDNF). Ketone supplements containing β-hydroxybutyrate (β-OHB) are a purported therapeutic strategy for improving brain health in at-risk populations. We tested the hypothesis that short-term β-OHB supplementation will elevate cerebral blood flow and BDNF, as well as improve cognition in adults with obesity. In a placebo-controlled double-blind, cross-over design, 14 adults with obesity (10 females; aged 56 ± 12 years; body mass index = 33.8 ± 6.9 kg m ) consumed 30 mL (12 g) of β-OHB or placebo thrice-daily for 14 days. Blood flow (Q) and cerebrovascular conductance (CVC) were measured in the common carotid (CCA), internal carotid (ICA) and vertebral (VA) arteries by duplex ultrasound. BDNF was measured by an enzyme-linked immunosorbent assay. Cognition was assessed by the digit-symbol substitution (DSST), Stroop and task-switching tests. Following 14 days of ketone supplementation, we observed significant improvements in cerebrovascular outcomes including Q (+12%), Q (+11%), VA (+12%) and VA shear rate (+10%). DSST performance significantly improved following ketone supplementation (+2.7 correct responses) and improved DSST performance was positively associated improvements in cerebrovascular outcomes including Q , CCA , Q and VA . By contrast to one hypothesis, β-OHB did not impact fasting serum and plasma BDNF. β-OHB supplementation improved cognition in adults with obesity, which may be partly facilitated by improvements in cerebral blood flow. β-OHB supplementation was well-tolerated and appears to be safe for cerebrovascular health, suggesting potential therapeutic benefits of β-OHB in a population at risk of neurocognitive impairment.
Key Points: People with obesity are at increased risk of neurocognitive dysfunction, partly as a result of -induced reductions in cerebral blood flow (CBF) and brain-derived neurotrophic factor (BDNF). Ketone supplements containing β-hydroxybutyrate (β-OHB) reduce postprandial hyperglycaemia, which may increase CBF and BDNF, thereby protecting against obesity-related cognitive dysfunction. We show for the first time that 14 days of thrice-daily β-OHB supplementation improves aspects of cognition and increases cerebrovascular flow, conductance and shear rate in the extracranial arteries of adults with obesity. Our preliminary data indicate a significant positive relationship between elevated CBF and improved cognition following β-OHB supplementation. This trial provides a foundation for the potential non-pharmacological therapeutic application of β-OHB supplementation in patient groups at risk of hyperglycaemic cerebrovascular disease and cognitive dysfunction.
Soni S, Tabatabaei Dakhili SA, Ussher JR, Dyck JRB.
American Journal of Physiology. Cell Physiology. 2024;326(2):C551-C566. doi:10.1152/ajpcell.00501.2023.
New Research
β-Hydroxybutyrate (βHB) is the major ketone in the body, and it is recognized as a metabolic energy source and an important signaling molecule. While ketone oxidation is essential in the brain during prolonged fasting/starvation, other organs such as skeletal muscle and the heart also use ketones as metabolic substrates. Additionally, βHB-mediated molecular signaling events occur in heart and skeletal muscle cells, and via metabolism and/or signaling, ketones may contribute to optimal skeletal muscle health and cardiac function. Of importance, when the use of ketones for ATP production and/or as signaling molecules becomes disturbed in the presence of underlying obesity, type 2 diabetes, and/or cardiovascular diseases, these changes may contribute to cardiometabolic disease. As a result of these disturbances in cardiometabolic disease, multiple approaches have been used to elevate circulating ketones with the goal of optimizing either ketone metabolism or ketone-mediated signaling. These approaches have produced significant improvements in heart and skeletal muscle during cardiometabolic disease with a wide range of benefits that include improved metabolism, weight loss, better glycemic control, improved cardiac and vascular function, as well as reduced inflammation and oxidative stress. Herein, we present the evidence that indicates that ketone therapy could be used as an approach to help treat cardiometabolic diseases by targeting cardiac and skeletal muscles.
Møller N.
The Journal of Clinical Endocrinology and Metabolism. 2020;105(9):dgaa370. doi:10.1210/clinem/dgaa370.
Ketone bodies -- beta-hydroxybutyrate (βHB), acetoacetate, and acetone -- are ancient, evolutionarily preserved, small fuel substrates, which uniquely can substitute and alternate with glucose under conditions of fuel and food deficiency. Once canonized as a noxious, toxic pathogen leading to ketoacidosis in patients with diabetes, it is now becoming increasingly clear that βHB possesses a large number of beneficial, life-preserving effects in the fields of clinical science and medicine. βHB, the most prominent ketone body, binds to specific hydroxyl-carboxylic acid receptors and inhibits histone deacetylase enzymes, free fatty acid receptors, and the NOD-like receptor protein 3 inflammasome, tentatively inhibiting lipolysis, inflammation, oxidative stress, cancer growth, angiogenesis, and atherosclerosis, and perhaps contributing to the increased longevity associated with exercise and caloric restriction. Clinically ketone bodies/ketogenic diets have for a long time been used to reduce the incidence of seizures in epilepsy and may have a role in the treatment of other neurological diseases such as dementia. βHB also acts to preserve muscle protein during systemic inflammation and is an important component of the metabolic defense against insulin-induced hypoglycemia. Most recently, a number of studies have reported that βHB dramatically increases myocardial blood flow and cardiac output in control subjects and patients with heart failure. At the moment, scientific interest in ketone bodies, in particular βHB, is in a hectic transit and, hopefully, future, much needed, controlled clinical studies will reveal and determine to which extent the diverse biological manifestations of βHB should be introduced medically.
He Y, Cheng X, Zhou T, et al.
Heliyon. 2023;9(11):e21098. doi:10.1016/j.heliyon.2023.e21098.
Previous studies have found that β-Hydroxybutyrate (BHB), the main component of ketone bodies, is of physiological importance as a backup energy source during starvation or induces diabetic ketoacidosis when insulin deficiency occurs. Ketogenic diets (KD) have been used as metabolic therapy for over a hundred years, it is well known that ketone bodies and BHB not only serve as ancillary fuel substituting for glucose but also induce anti-oxidative, anti-inflammatory, and cardioprotective features via binding to several target proteins, including histone deacetylase (HDAC), or G protein-coupled receptors (GPCRs). Recent advances in epigenetics, especially novel histone post-translational modifications (HPTMs), have continuously updated our understanding of BHB, which also acts as a signal transduction molecule and modification substrate to regulate a series of epigenetic phenomena, such as histone acetylation, histone β-hydroxybutyrylation, histone methylation, DNA methylation, and microRNAs. These epigenetic events alter the activity of genes without changing the DNA structure and further participate in the pathogenesis of related diseases. This review focuses on the metabolic process of BHB and BHB-mediated epigenetics in cardiovascular diseases, diabetes and complications of diabetes, neuropsychiatric diseases, cancers, osteoporosis, liver and kidney injury, embryonic and fetal development, and intestinal homeostasis, and discusses potential molecular mechanisms, drug targets, and application prospects.
Soto-Mota A, Norwitz NG, Clarke K.
Biochemical Society Transactions. 2020;48(1):51-59. doi:10.1042/BST20190240.
Much of the world's prominent and burdensome chronic diseases, such as diabetes, Alzheimer's, and heart disease, are caused by impaired metabolism. By acting as both an efficient fuel and a powerful signalling molecule, the natural ketone body, d-β-hydroxybutyrate (βHB), may help circumvent the metabolic malfunctions that aggravate some diseases. Historically, dietary interventions that elevate βHB production by the liver, such as high-fat diets and partial starvation, have been used to treat chronic disease with varying degrees of success, owing to the potential downsides of such diets. The recent development of an ingestible βHB monoester provides a new tool to quickly and accurately raise blood ketone concentration, opening a myriad of potential health applications. The βHB monoester is a salt-free βHB precursor that yields only the biologically active d-isoform of the metabolite, the pharmacokinetics of which have been studied, as has safety for human consumption in athletes and healthy volunteers. This review describes fundamental concepts of endogenous and exogenous ketone body metabolism, the differences between the βHB monoester and other exogenous ketones and summarises the disease-specific biochemical and physiological rationales behind its clinical use in diabetes, neurodegenerative diseases, heart failure, sepsis related muscle atrophy, migraine, and epilepsy. We also address the limitations of using the βHB monoester as an adjunctive nutritional therapy and areas of uncertainty that could guide future research.
Robberechts R, Poffé C.
American Journal of Physiology. Cell Physiology. 2024;326(1):C143-C160. doi:10.1152/ajpcell.00485.2023.
Over the last decade, there has been a growing interest in the use of ketone supplements to improve athletic performance. These ketone supplements transiently elevate the concentrations of the ketone bodies acetoacetate (AcAc) and d-β-hydroxybutyrate (βHB) in the circulation. Early studies showed that ketone bodies can improve energetic efficiency in striated muscle compared with glucose oxidation and induce a glycogen-sparing effect during exercise. As such, most research has focused on the potential of ketone supplementation to improve athletic performance via ingestion of ketones immediately before or during exercise. However, subsequent studies generally observed no performance improvement, and particularly not under conditions that are relevant for most athletes. However, more and more studies are reporting beneficial effects when ketones are ingested after exercise. As such, the real potential of ketone supplementation may rather be in their ability to enhance postexercise recovery and training adaptations. For instance, recent studies observed that postexercise ketone supplementation (PEKS) blunts the development of overtraining symptoms, and improves sleep, muscle anabolic signaling, circulating erythropoietin levels, and skeletal muscle angiogenesis. In this review, we provide an overview of the current state-of-the-art about the impact of PEKS on aspects of exercise recovery and training adaptation, which is not only relevant for athletes but also in multiple clinical conditions. In addition, we highlight the underlying mechanisms by which PEKS may improve exercise recovery and training adaptation. This includes epigenetic effects, signaling via receptors, modulation of neurotransmitters, energy metabolism, and oxidative and anti-inflammatory pathways.
Shahtaghi NR, Soni B, Bakrey H, Bigdelitabar S, Jain SK.
Current Drug Targets. 2024;25(14):919-933. doi:10.2174/0113894501312168240821082224.
New Research
β-hydroxybutyrate (BHB) is a ketone body that serves as an alternative energy source for various tissues, including the brain, heart, and skeletal muscle. As a metabolic intermediate and signaling molecule, BHB plays a crucial role in modulating cellular and physiological processes. Notably, BHB supplementation offers a novel and promising strategy to induce nutritional ketosis without the need for strict dietary adherence or causing nutritional deficiencies. This review article provides an overview of BHB metabolism and explores its applications in age-related diseases. This review conducted a comprehensive search of PubMed, ScienceDirect, and other relevant English-language articles. The main findings were synthesized, and discussed the challenges, limitations, and future directions of BHB supplementation. BHB supplementation holds potential benefits for various diseases and conditions, including neurodegenerative disorders, cardiovascular diseases, cancers, and inflammation. BHB acts through multiple mechanisms, including interactions with cell surface receptors, intracellular enzymes, transcription factors, signaling molecules, and epigenetic modifications. Despite its promise, BHB supplementation faces several challenges, such as determining the optimal dosage, ensuring long-term safety, identifying the most effective type and formulation, establishing biomarkers of response, and conducting cost-effectiveness analyses. BHB supplementation opens exciting avenues for research, including investigating molecular mechanisms, refining optimization strategies, exploring innovation opportunities, and assessing healthspan and lifespan benefits. BHB supplementation represents a new frontier in health research, offering a potential pathway to enhance well-being and extend lifespan.
Exogenous Ketone Supplements in Athletic Contexts: Past, Present, and Future. Evans M, McClure TS, Koutnik AP, Egan B. Sports Medicine (Auckland, N.Z.). 2022;52(Suppl 1):25-67. doi:10.1007/s40279-022-01756-2. (Leading Journal)
Jang J, Kim SR, Lee JE, et al.
International Journal of Molecular Sciences. 2023;25(1):124. doi:10.3390/ijms25010124.
Ketone bodies (KBs), such as acetoacetate and β-hydroxybutyrate, serve as crucial alternative energy sources during glucose deficiency. KBs, generated through ketogenesis in the liver, are metabolized into acetyl-CoA in extrahepatic tissues, entering the tricarboxylic acid cycle and electron transport chain for ATP production. Reduced glucose metabolism and mitochondrial dysfunction correlate with increased neuronal death and brain damage during cerebral ischemia and neurodegeneration. Both KBs and the ketogenic diet (KD) demonstrate neuroprotective effects by orchestrating various cellular processes through metabolic and signaling functions. They enhance mitochondrial function, mitigate oxidative stress and apoptosis, and regulate epigenetic and post-translational modifications of histones and non-histone proteins. Additionally, KBs and KD contribute to reducing neuroinflammation and modulating autophagy, neurotransmission systems, and gut microbiome. This review aims to explore the current understanding of the molecular mechanisms underpinning the neuroprotective effects of KBs and KD against brain damage in cerebral ischemia and neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease.
Julio-Amilpas A, Montiel T, Soto-Tinoco E, Gerónimo-Olvera C, Massieu L.
Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism. 2015;35(5):851-60. doi:10.1038/jcbfm.2015.1.
Glucose is the main energy substrate in brain but in certain circumstances such as prolonged fasting and the suckling period alternative substrates can be used such as the ketone bodies (KB), beta-hydroxybutyrate (BHB), and acetoacetate. It has been shown that KB prevent neuronal death induced during energy limiting conditions and excitotoxicity. The protective effect of KB has been mainly attributed to the improvement of mitochondrial function. In the present study, we have investigated the protective effect of D-BHB against neuronal death induced by severe noncoma hypoglycemia in the rat in vivo and by glucose deprivation (GD) in cortical cultures. Results show that systemic administration of D-BHB reduces reactive oxygen species (ROS) production in distinct cortical areas and subregions of the hippocampus and efficiently prevents neuronal death in the cortex of hypoglycemic animals. In vitro results show that D-BHB stimulates ATP production and reduces ROS levels, while the nonphysiologic isomer of BHB, L-BHB, has no effect on energy production but reduces ROS levels. Data suggest that protection by BHB, not only results from its metabolic action but is also related to its capability to reduce ROS, rendering this KB as a suitable candidate for the treatment of ischemic and traumatic injury.
Gómora-García JC, Montiel T, Hüttenrauch M, et al.
Cells. 2023;12(3):486. doi:10.3390/cells12030486.
Mitochondrial activity and quality control are essential for neuronal homeostasis as neurons rely on glucose oxidative metabolism. The ketone body, D-β-hydroxybutyrate (D-BHB), is metabolized to acetyl-CoA in brain mitochondria and used as an energy fuel alternative to glucose. We have previously reported that D-BHB sustains ATP production and stimulates the autophagic flux under glucose deprivation in neurons; however, the effects of D-BHB on mitochondrial turnover under physiological conditions are still unknown. Sirtuins (SIRTs) are NAD-activated protein deacetylases involved in the regulation of mitochondrial biogenesis and mitophagy through the activation of transcription factors FOXO1, FOXO3a, TFEB and PGC1α coactivator. Here, we aimed to investigate the effect of D-BHB on mitochondrial turnover in cultured neurons and the mechanisms involved. Results show that D-BHB increased mitochondrial membrane potential and regulated the NAD/NADH ratio. D-BHB enhanced FOXO1, FOXO3a and PGC1α nuclear levels in an SIRT2-dependent manner and stimulated autophagy, mitophagy and mitochondrial biogenesis. These effects increased neuronal resistance to energy stress. D-BHB also stimulated the autophagic-lysosomal pathway through AMPK activation and TFEB-mediated lysosomal biogenesis. Upregulation of SIRT2, FOXOs, PGC1α and TFEB was confirmed in the brain of ketogenic diet (KD)-treated mice. Altogether, the results identify SIRT2, for the first time, as a target of D-BHB in neurons, which is involved in the regulation of autophagy/mitophagy and mitochondrial quality control.
Jensen NJ, Wodschow HZ, Nilsson M, Rungby J.
International Journal of Molecular Sciences. 2020;21(22):E8767. doi:10.3390/ijms21228767.
Under normal physiological conditions the brain primarily utilizes glucose for ATP generation. However, in situations where glucose is sparse, e.g., during prolonged fasting, ketone bodies become an important energy source for the brain. The brain's utilization of ketones seems to depend mainly on the concentration in the blood, thus many dietary approaches such as ketogenic diets, ingestion of ketogenic medium-chain fatty acids or exogenous ketones, facilitate significant changes in the brain's metabolism. Therefore, these approaches may ameliorate the energy crisis in neurodegenerative diseases, which are characterized by a deterioration of the brain's glucose metabolism, providing a therapeutic advantage in these diseases. Most clinical studies examining the neuroprotective role of ketone bodies have been conducted in patients with Alzheimer's disease, where brain imaging studies support the notion of enhancing brain energy metabolism with ketones. Likewise, a few studies show modest functional improvements in patients with Parkinson's disease and cognitive benefits in patients with-or at risk of-Alzheimer's disease after ketogenic interventions. Here, we summarize current knowledge on how ketogenic interventions support brain metabolism and discuss the therapeutic role of ketones in neurodegenerative disease, emphasizing clinical data.
Llorente-Folch I, Düssmann H, Watters O, Connolly NMC, Prehn JHM.
Scientific Reports. 2023;13(1):19664. doi:10.1038/s41598-023-46776-8.
The ketogenic diet is an emerging therapeutic approach for refractory epilepsy, as well as certain rare and neurodegenerative disorders. The main ketone body, β-hydroxybutyrate (BHB), is the primary energy substrate endogenously produced in a ketogenic diet, however, mechanisms of its therapeutic actions remain unknown. Here, we studied the effects of BHB on mitochondrial energetics, both in non-stimulated conditions and during glutamate-mediated hyperexcitation. We found that glutamate-induced hyperexcitation stimulated mitochondrial respiration in cultured cortical neurons, and that this response was greater in cultures supplemented with BHB than with glucose. BHB enabled a stronger and more sustained maximal uncoupled respiration, indicating that BHB enables neurons to respond more efficiently to increased energy demands such as induced during hyperexcitation. We found that cytosolic Ca was required for BHB-mediated enhancement of mitochondrial function, and that this enhancement was independent of the mitochondrial glutamate-aspartate carrier, Aralar/AGC1. Our results suggest that BHB exerts its protective effects against hyperexcitation by enhancing mitochondrial function through a Ca-dependent, but Aralar/AGC1-independent stimulation of mitochondrial respiration.
Molloy JW, Barry D.
Journal of Neuroscience Research. 2024;102(5):e25342. doi:10.1002/jnr.25342.
Glucose is the primary energy source for neural stem cells (NSCs), supporting their proliferation, differentiation, and quiescence. However, the high demand for glucose during brain development often exceeds its supply, leading to the utilization of alternative energy sources including ketone bodies. Ketone bodies, including β-hydroxybutyrate, are short-chain fatty acids produced through hepatic ketogenesis and play a crucial role in providing energy and the biosynthetic components for NSCs when required. The interplay between glucose and ketone metabolism influences NSC behavior and fate decisions, and disruptions in these metabolic pathways have been linked to neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Additionally, ketone bodies exert neuroprotective effects on NSCs and modulate cellular responses to oxidative stress, energy maintenance, deacetylation, and inflammation. As such, understanding the interdependence of glucose and ketone metabolism in NSCs is crucial to understanding their roles in NSC function and their implications for neurological conditions. This article reviews the mechanisms of glucose and ketone utilization in NSCs, their impact on NSC function, and the therapeutic potential of targeting these metabolic pathways in neurological disorders.
Li C, Chai X, Pan J, et al.
Journal of Molecular Neuroscience : MN. 2022;72(5):923-938. doi:10.1007/s12031-022-01974-3.
Hypoglycemia has emerged as a prominent complication in anti-diabetic drug therapy or negative energy balance of animals, which causes brain damage, cognitive impairment, and even death. Brain injury induced by hypoglycemia is closely related to oxidative stress and the production of reactive oxygen species (ROS). The intracellular accumulation of ROS leads to neuronal damage, even death. Ketone body β-hydroxybutyrate (BHBA) not only serves as alternative energy source for glucose in extrahepatic tissues, but is also involved in cellular signaling transduction. Previous studies showed that BHBA reduces apoptosis by inhibiting the excessive production of ROS and activation of caspase-3. However, the effects of BHBA on apoptosis induced by glucose deprivation and its related molecular mechanisms have been seldom reported. In the present study, PC12 cells and primary cortical neurons were used to establish a low glucose injury model. The effects of BHBA on the survival and apoptosis in a glucose deficient condition and related molecular mechanisms were investigated by using flow cytometry, immunofluorescence, and western blotting. PC12 cells were incubated with 1 mM glucose for 24 h as a low glucose cell model, in which ROS accumulation and cell mortality were significantly increased. After 24 h and 48 h treatment with different concentrations of BHBA (0 mM, 0.05 mM, 0.5 mM, 1 mM, 2 mM), ROS production was significantly inhibited. Moreover, cell apoptosis rate was decreased and survival rate was significantly increased in 1 mM and 2 mM BHBA groups. In primary cortical neurons, at 24 h after treatment with 2 mM BHBA, the injured length and branch of neurites were significantly improved. Meanwhile, the intracellular ROS level, the proportion of c-Fos cells, apoptosis rate, and nuclear translocation of NF-κB protein after treatment with BHBA were significantly decreased when compared with that in low glucose cells. Importantly, the expression of p38, p-p38, NF-κB, and caspase-3 were significantly decreased, while the expression of p-ERK was significantly increased in both PC12 cells and primary cortical neurons. Our results demonstrate that BHBA decreased the accumulation of intracellular ROS, and further inhibited cell apoptosis by mediating the p38 MAPK signaling pathway and caspase-3 apoptosis cascade during glucose deprivation. In addition, BHBA inhibited apoptosis by activating ERK phosphorylation and alleviated the damage of low glucose to PC12 cells and primary cortical neurons. These results provide new insight into the anti-apoptotic effect of BHBA in a glucose deficient condition and the related signaling cascade.
Ehtiati S, Hatami B, Khatami SH, et al.
Journal of Cellular Biochemistry. 2025;126(6):e70050. doi:10.1002/jcb.70050.
New Research