Decanoic acid inhibits mTORC1 activity independent of glucose and insulin signaling

Microcin Y utilizes its stable structure and biological activity to regulate the metabolism of intestinal probiotics and effectively clear gut Salmonella

MccY is a novel, structurally stable microcin with antibacterial activity against Enterobacteriaceae. However, the bioavailability of orally administrated MccY is unknown. This study evaluated the effects of MccY as a antimicrobial on pre-digestion in vitro and its intake, digestion and gut metabolism in vivo. The result of pre-digestion results that MccY maintained its biological activity and was resistant to decomposition. The study established a safe threshold of 4.46-9.92 mg/kg for the MccY dosage-body weight relationship in BALB/c mice. Mice fed with MccY demonstrated improved body weight and intestinal barrier function, accompanied with increased IgM immunogenicity and decreased levels of TNF-α, IL-6, and IL-10 in the intestine. MccY significantly facilitates the growth and activity of probiotics including Lactobacillus, Prevotella, and Bacteroides, and leading to the production of SCFAs and MCFAs during bacterial interactions. Furthermore, MccY effectively protects against the inflammatory response caused by Salmonella Typhimurium infection and effectively clears the Salmonella bacteria from the gut. In conclusion, MccY is seen as a promising new therapeutic target drug for enhancing the intestinal microbe-barrier axis and preventing enteritis.

Inflammation and oxidative stress in epileptic children: from molecular mechanisms to clinical application of ketogenic diet

Childhood epilepsy affects up to 1 % of children. It has been shown that 30 % of patients are resistant to drug treatments, making further investigation of other potential treatment strategies necessary. One such approach is the ketogenic diet (KD) showing promising results and potential benefits beyond the use of current antiepileptic drugs. This study aims to investigate the effects of KD on inflammation and oxidative stress, as one of the main suggested mechanisms of neuroprotection, in children with epilepsy. This narrative review was conducted using the Medline and Google Scholar databases, and by searching epilepsy, drug-resistant epilepsy, child, children, ketogenic, ketogenic diet, diet, ketogenic, keto, ketone bodies (BHB), PUFA, gut microbiota, inflammation, inflammation mediators, neurogenic inflammation, neuroinflammation, inflammatory marker, adenosine modulation, mitochondrial function, MTOR pathway, Nrf2 pathway, mitochondrial dysfunction, PPARɣ, oxidative stress, ROS/RNS, and stress oxidative as keywords. Compelling evidence underscores inflammation and oxidative stress as pivotal factors in epilepsy, even in cases with genetic origins. The ketogenic diet effectively addresses these factors by reducing ROS and RNS, enhancing antioxidant defenses, improving mitochondrial function, and regulating inflammatory genes. Additionally, KD curbs pro-inflammatory cytokine and chemokine production by dampening NF-κB activation, inhibiting the NLRP3 inflammasome, increasing brain adenosine levels, mTOR pathway inhibition, upregulating PPARɣ expression, and promoting a healthy gut microbiota while emphasizing the consumption of healthy fats. KD could be considered a promising therapeutic intervention in patients with epilepsy particularly in drug-resistant epilepsy cases, due to its targeted approach addressing oxidative stress and inflammatory mechanisms.

Developing a Tanshinone IIA Memetic by Targeting MIOS to Regulate mTORC1 and Autophagy in Glioblastoma

Tanshinone IIA (T2A) is a bioactive compound that provides promise in the treatment of glioblastoma multiforme (GBM), with a range of molecular mechanisms including the inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) and the induction of autophagy. Recently, T2A has been demonstrated to function through sestrin 2 (SESN) to inhibit mTORC1 activity, but its possible impact on autophagy through this pathway has not been investigated. Here, the model system Dictyostelium discoideum and GBM cell lines were employed to investigate the cellular role of T2A in regulating SESN to inhibit mTORC1 and activate autophagy through a GATOR2 component MIOS. In D. discoideum, T2A treatment induced autophagy and inhibited mTORC1 activity, with both effects lost upon the ablation of SESN (sesn-) or MIOS (mios-). We further investigated the targeting of MIOS to reproduce this effect of T2A, where computational analysis identified 25 novel compounds predicted to strongly bind the human MIOS protein, with one compound (MIOS inhibitor 3; Mi3) reducing cell proliferation in two GBM cells. Furthermore, Mi3 specificity was demonstrated through the loss of potency in the D. discoideum mios- cells regarding cell proliferation and the induction of autophagy. In GBM cells, Mi3 treatment also reduced mTORC1 activity and induced autophagy. Thus, a potential T2A mimetic showing the inhibition of mTORC1 and induction of autophagy in GBM cells was identified.

Functional mechanism study of the allelochemical myrigalone A identifies a group of ultrapotent inhibitors of ethylene biosynthesis in plants

Allelochemicals represent a class of natural products released by plants as root, leaf, and fruit exudates that interfere with the growth and survival of neighboring plants. Understanding how allelochemicals function to regulate plant responses may provide valuable new approaches to better control plant function. One such allelochemical, Myrigalone A (MyA) produced by Myrica gale, inhibits seed germination and seedling growth through an unknown mechanism. Here, we investigate MyA using the tractable model Dictyostelium discoideum and reveal that its activity depends on the conserved homolog of the plant ethylene synthesis protein 1-aminocyclopropane-1-carboxylic acid oxidase (ACO). Furthermore, in silico modeling predicts the direct binding of MyA to ACO within the catalytic pocket. In D. discoideum, ablation of ACO mimics the MyA-dependent developmental delay, which is partially restored by exogenous ethylene, and MyA reduces ethylene production. In Arabidopsis thaliana, MyA treatment delays seed germination, and this effect is rescued by exogenous ethylene. It also mimics the effect of established ACO inhibitors on root and hypocotyl extension, blocks ethylene-dependent root hair production, and reduces ethylene production. Finally, in silico binding analyses identify a range of highly potent ethylene inhibitors that block ethylene-dependent response and reduce ethylene production in Arabidopsis. Thus, we demonstrate a molecular mechanism by which the allelochemical MyA reduces ethylene biosynthesis and identify a range of ultrapotent inhibitors of ethylene-regulated responses.

Multiomics analysis revealed the mechanism of the anti-diabetic effect of Salecan

Salecan, a natural β-glucan compromising nine residues connected by β-(1 → 3)/α-(1 → 3) glycosidic bonds, is one of the newly approved food ingredients. Salecan has multiple health-improving effects, yet its mechanism against Type 2 diabetes mellitus (T2DM) remains poorly understood. In this study, the hypoglycemic effect and underlying mechanism of Salecan intervention on STZ-induced diabetic model mice were investigated. After 8 weeks of gavage, Salecan attenuated insulin resistance and repaired pancreatic β cells in a dose-dependent manner. In addition, Salecan supplement remodel the structure of the gut microbiota and altered the level of intestinal metabolites. Serum metabolites, especially unsaturated fatty acids, were also affected significantly. In addition, tight junction proteins in the colon and autophagy-related proteins in the pancreas were upregulated. Multiomics analysis indicated that Lactobacillus johnsonii, Muribaculaceae, and Lachnoclostridium were highly associated with fatty acid esters of hydroxy fatty acids (FAHFA) levels in the colon, accordingly enhancing arachidonic acid and linoleic acid in serum, and promoting GLP-1 release in the intestine and insulin secretion in the pancreas, thus relieving insulin resistance and exhibiting hypoglycemic effects. These findings provide a novel understanding of the anti-diabetic effect of Salecan in mice from a molecular perspective, paving the way for the wide use of Salecan.

Mutation Screening of Dictyostelium Restriction Enzyme-Mediated Integration (REMI) Libraries

Identifying the mechanisms of action of existing and novel drugs is essential for the development of new compounds for therapeutic and commercial use. Here we provide a technique to identify these mechanisms through isolating mutant cell lines that show resistance to drug-induced phenotypes using Dictyostelium discoideum REMI libraries. This approach provides a robust and rapid chemical-genetic screening technique that enables an unbiased approach to identify proteins and molecular pathways that control drug sensitivity. Mutations that result in drug resistance often occur in target proteins thus identifying the specific protein targets for drugs and bioactive natural products. Following the identification of a list of putative molecular targets user selected compound targets can be analyzed to confirm and validate direct inhibitory effects.

Ketogenic diet therapy for pediatric epilepsy is associated with alterations in the human gut microbiome that confer seizure resistance in mice

The gut microbiome modulates seizure susceptibility and the anti-seizure effects of the ketogenic diet (KD) in animal models, but whether these relationships translate to KD therapies for human epilepsy is unclear. We find that the clinical KD alters gut microbial function in children with refractory epilepsy. Colonizing mice with KD-associated microbes promotes seizure resistance relative to matched pre-treatment controls. Select metagenomic and metabolomic features, including those related to anaplerosis, fatty acid β-oxidation, and amino acid metabolism, are seen with human KD therapy and preserved upon microbiome transfer to mice. Mice colonized with KD-associated gut microbes exhibit altered hippocampal transcriptomes, including pathways related to ATP synthesis, glutathione metabolism, and oxidative phosphorylation, and are linked to susceptibility genes identified in human epilepsy. Our findings reveal key microbial functions that are altered by KD therapies for pediatric epilepsy and linked to microbiome-induced alterations in brain gene expression and seizure protection in mice.

The Evolving Landscape of Therapeutics for Epilepsy in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a rare multisystem genetic disorder characterized by benign tumor growth in multiple organs, including the brain, kidneys, heart, eyes, lungs, and skin. Pathogenesis stems from mutations in either the TSC1 or TSC2 gene, which encode the proteins hamartin and tuberin, respectively. These proteins form a complex that inhibits the mTOR pathway, a critical regulator of cell growth and proliferation. Disruption of the tuberin-hamartin complex leads to overactivation of mTOR signaling and uncontrolled cell growth, resulting in hamartoma formation. Neurological manifestations are common in TSC, with epilepsy developing in up to 90% of patients. Seizures tend to be refractory to medical treatment with anti-seizure medications. Infantile spasms and focal seizures are the predominant seizure types, often arising in early childhood. Drug-resistant epilepsy contributes significantly to morbidity and mortality. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, clinical manifestations, and treatment approaches for epilepsy and other neurological features of TSC. While narrative reviews on TSC exist, this review uniquely synthesizes key advancements across the areas of TSC neuropathology, conventional and emerging pharmacological therapies, and targeted treatments. The review is narrative in nature, without any date restrictions, and summarizes the most relevant literature on the neurological aspects and management of TSC. By consolidating the current understanding of TSC neurobiology and evidence-based treatment strategies, this review provides an invaluable reference that highlights progress made while also emphasizing areas requiring further research to optimize care and outcomes for TSC patients.

Decanoic Acid Rescues Differences in AMPA-Mediated Calcium Rises in Hippocampal CA1 Astrocytes and Neurons in the 5xFAD Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD), a devastating neurodegenerative disease characterized by cognitive dysfunctions, is associated with high levels of amyloid beta 42 (Aβ42), which is believed to play a role in cellular damage and signaling changes in AD. Decanoic acid has been shown to be therapeutic in AD. Glutamatergic signaling within neurons and astrocytes of the CA1 region of the hippocampus is critical in cognitive processes, and previous work has indicated deficiencies in this signaling in a mouse model of AD. In this study, we investigated glutamate-mediated signaling by evaluating AMPA-mediated calcium rises in female and male CA1 neurons and astrocytes in a mouse model of AD and examined the potential of decanoic acid to normalize this signaling. In brain slices from 5xFAD mice in which there are five mutations leading to increasing levels of Aβ42, AMPA-mediated calcium transients in CA1 neurons and astrocytes were significantly lower than that seen in wildtype controls in both females and males. Interestingly, incubation of 5xFAD slices in decanoic acid restored AMPA-mediated calcium levels in neurons and astrocytes in both females and males to levels indistinguishable from those seen in wildtype, whereas similar exposure to decanoic acid did not result in changes in AMPA-mediated transients in neurons or astrocytes in either sex in the wildtype. Our data indicate that one mechanism by which decanoic acid could improve cognitive functioning is through normalizing AMPA-mediated signaling in CA1 hippocampal cells.

Potential benefits of medium chain fatty acids in aging and neurodegenerative disease

Neurodegenerative diseases are a large class of neurological disorders characterized by progressive dysfunction and death of neurones. Examples include Alzheimer's disease, Parkinson's disease, frontotemporal dementia, and amyotrophic lateral sclerosis. Aging is the primary risk factor for neurodegeneration; individuals over 65 are more likely to suffer from a neurodegenerative disease, with prevalence increasing with age. As the population ages, the social and economic burden caused by these diseases will increase. Therefore, new therapies that address both aging and neurodegeneration are imperative. Ketogenic diets (KDs) are low carbohydrate, high-fat diets developed initially as an alternative treatment for epilepsy. The classic ketogenic diet provides energy via long-chain fatty acids (LCFAs); naturally occurring medium chain fatty acids (MCFAs), on the other hand, are the main components of the medium-chain triglyceride (MCT) ketogenic diet. MCT-based diets are more efficient at generating the ketone bodies that are used as a secondary energy source for neurones and astrocytes. However, ketone levels alone do not closely correlate with improved clinical symptoms. Recent findings suggest an alternative mode of action for the MCFAs, e.g., via improving mitochondrial biogenesis and glutamate receptor inhibition. MCFAs have been linked to the treatment of both aging and neurodegenerative disease via their effects on metabolism. Through action on multiple disease-related pathways, MCFAs are emerging as compounds with notable potential to promote healthy aging and ameliorate neurodegeneration. MCFAs have been shown to stimulate autophagy and restore mitochondrial function, which are found to be disrupted in aging and neurodegeneration. This review aims to provide insight into the metabolic benefits of MCFAs in neurodegenerative disease and healthy aging. We will discuss the use of MCFAs to combat dysregulation of autophagy and mitochondrial function in the context of "normal" aging, Parkinson's disease, amyotrophic lateral sclerosis and Alzheimer's disease.

Enhanced Sestrin expression through Tanshinone 2A treatment improves PI3K-dependent inhibition of glioma growth

Glioblastomas are a highly aggressive cancer type which respond poorly to current pharmaceutical treatments, thus novel therapeutic approaches need to be investigated. One such approach involves the use of the bioactive natural product Tanshinone IIA (T2A) derived from the Chinese herb Danshen, where mechanistic insight for this anti-cancer agent is needed to validate its use. Here, we employ a tractable model system, Dictyostelium discoideum, to provide this insight. T2A potently inhibits cellular proliferation of Dictyostelium, suggesting molecular targets in this model. We show that T2A rapidly reduces phosphoinositide 3 kinase (PI3K) and protein kinase B (PKB) activity, but surprisingly, the downstream complex mechanistic target of rapamycin complex 1 (mTORC1) is only inhibited following chronic treatment. Investigating regulators of mTORC1, including PKB, tuberous sclerosis complex (TSC), and AMP-activated protein kinase (AMPK), suggests these enzymes were not responsible for this effect, implicating an additional molecular mechanism of T2A. We identify this mechanism as the increased expression of sestrin, a negative regulator of mTORC1. We further show that combinatory treatment using a PI3K inhibitor and T2A gives rise to a synergistic inhibition of cell proliferation. We then translate our findings to human and mouse-derived glioblastoma cell lines, where both a PI3K inhibitor (Paxalisib) and T2A reduces glioblastoma proliferation in monolayer cultures and in spheroid expansion, with combinatory treatment significantly enhancing this effect. Thus, we propose a new approach for cancer treatment, including glioblastomas, through combinatory treatment with PI3K inhibitors and T2A.

Potential of Capric Acid in Neurological Disorders: An Overview

To solve the restrictions of a classical ketogenic diet, a modified medium-chain triglyceride diet was introduced which required only around 60% of dietary energy. Capric acid (CA), a small molecule, is one of the main components because its metabolic profile offers itself as an alternate source of energy to the brain in the form of ketone bodies. This is possible with the combined capability of CA to cross the blood-brain barrier and achieve a concentration of 50% concentration in the brain more than any other fatty acid in plasma. Natural sources of CA include vegetable oils such as palm oil and coconut oil, mammalian milk and some seeds. Several studies have shown that CA has varied action on targets that include AMPA receptors, PPAR-γ, inflammatory/oxidative stress pathways and gut dysbiosis. Based on these lines of evidence, CA has proved to be effective in the amelioration of neurological diseases such as epilepsy, affective disorders and Alzheimer's disease. But these studies still warrant more pre-clinical and clinical studies that would further prove its efficacy. Hence, to understand the potential of CA in brain disease and associated comorbid conditions, an advance and rigorous molecular mechanistic study, apart from the reported in-vitro/in-vivo studies, is urgently required for the development of this compound through clinical setups.

Evaluation of antibacterial, antioxidant, and anti-inflammatory properties of GC/MS characterized methanol leaf extract of Terminalia superba (Combretaceae, Engl. & Diels)

Background

Terminalia superba is a well-known medicinal plant used in folk medicine for the management of various diseases and swelling. Validation of its efficacy in standardized scientific models is lacking. This gap needs to be filled as a way of enhancing modern drug discovery. The aim is to evaluate the antibacterial, antioxidant, and anti-inflammatory properties of T. superba in known and established models. Also, to establish and possibly correlate the established activity with the phytochemicals identified using GC/MS and qualitative methods.

Results

The result showed a dose-dependent percentage inhibition of DPPH, HO•, and Fe3+ reducing activity. The antibacterial activity showed dose-dependent significant (p < 0.05) inhibition against all the organisms used. The anti-inflammatory activity of METS was confirmed in the carrageenan model with significant (p < 0.05) inhibition of paw volume when compared to control while significantly decreasing (p < 0.05) weight of xylene-induced ear. For instance, after 6 h, there was  a reduction of 42%, 33%, and 22% for diclofenac, 200 mg, and 100 mg, respectively, as against 4% in control. The significant (p < 0.05) increase in MDA was attenuated by the treatment with METS dose dependently. Phytochemical assay and GC/MS characterization showed that alkaloids, saponins, phenols, quinone, tannins, coumarins, proteins, flavonoids, and amino acids were dominant with fatty acids accounting for 53%. Others are esters (23%), organic compounds (12%), alkanes (9%), and carboxylic acids (3%).

Conclusions

T. superba possesses antioxidant, antibacterial, and anti-inflammatory properties which are believed to arise from the secondary metabolites observed in the GC–MS characterization.

Graphical Abstract

A pre-column derivatization high-performance liquid chromatography method for simultaneous determination of short-chain and medium-chain fatty acids in a fecal sample

Short-chain and medium-chain fatty acids have plentiful biological functions, which play a crucial role in the diagnosis and therapy of many diseases. Herein, a new method for simultaneous quantifying 17 short-chain and medium-chain fatty acids with high-performance liquid chromatography coupled with an ultraviolet detector was developed and the pre-column derivatization by indole-3-acetic acid hydrazide was performed to improve the separation and detection. The conditions of the derivatization reaction were systematically investigated. Subsequently, the method was validated and the results showed a satisfactory linearity (linear regression coefficients > 0.9969), the limit of detection (4.0×10^-3 -1.9×10^-2 μmol/L), precision (0.9%-7.3% for intra-day and 2.0%-9.8% for inter-day), recovery (90.0%-109.1% with relative standard deviation <7.7%) and stability (0.1%-3.3% for standard solution and 0.2%-3.9% for fecal sample). Finally, the established method was successfully applied to quantify short-chain and medium-chain fatty acids in the feces of healthy control and diabetic rats. Eleven kinds of short-chain and medium-chain fatty acids were detected and six of them showed a significant difference between the control group and the model group.

The role of nutrition in canine idiopathic epilepsy management: Fact or fiction?

In the last decade, nutrition has gained interest in the management of canine idiopathic epilepsy (IE) based on growing scientific evidence. Diets can serve their functions through many pathways. One potential pathway includes the microbiota-gut-brain axis, which highlights the relationship between the brain and the intestines. Changing the brain's energy source and a number of dietary sourced anti-inflammatory and neuroprotective factors appears to be the basis for improved outcomes in IE. Selecting a diet with anti-seizure effects and avoiding risks of proconvulsant mediators as well as interference with anti-seizure drugs should all be considered in canine IE. This literature review provides information about preclinical and clinical evidence, including a systematic evaluation of the level of evidence, suggested mechanism of action and interaction with anti-seizure drugs as well as pros and cons of each potential dietary adaptation in canine IE.

Insights into the Cellular Interactions and Molecular Mechanisms of Ketogenic Diet for Comprehensive Management of Epilepsy

A high-fat diet with appropriate protein and low carbohydrate content, widely known as the ketogenic diet (KD), is considered as an effective non-pharmacotherapeutic treatment option for certain types of epilepsies. Several preclinical and clinical studies have been carried out to elucidate its mechanism of antiepileptic action. Ketone bodies produced after KD's breakdown interact with cellular excito-inhibitory processes and inhibit abnormal neuronal firing. The generated ketone bodies decrease glutamate release by inhibiting the vesicular glutamate transporter 1 and alter the transmembrane potential by hyperpolarization. Apart from their effect on the well-known pathogenic mechanisms of epilepsy, some recent studies have shown the interaction of KD metabolites with novel neuronal targets, particularly adenosine receptors, adenosine triphosphate-sensitive potassium channel, mammalian target of rapamycin, histone deacetylase, hydroxycarboxylic acid receptors, and the NLR family pyrin domain containing 3 inflammasomes to suppress seizures. The role of KD in augmenting gut microbiota as a potential mechanism for epileptic seizure suppression has been established. Furthermore, some recent findings also support the beneficial effect of KD against epilepsy- associated comorbidities. Despite several advantages of the KD in epilepsy management, its use is also associated with a wide range of side effects. Hypoglycemia, excessive ketosis, acidosis, renal stones, cardiomyopathies, and other metabolic disturbances are the primary adverse effects observed with the use of KD. However, in some recent studies, modified KD has been tested with lesser side effects and better tolerability. The present review discusses the molecular mechanism of KD and its role in managing epilepsy and its associated comorbidities.

A novel AMPK activator shows therapeutic potential in hepatocellular carcinoma by suppressing HIF1α-mediated aerobic glycolysis

Hepatocellular carcinoma (HCC) is characterized by rapid growth, early vascular invasion, and high metastasis. Currently available US Food and Drug Administration (FDA)-approved drugs show low therapeutic efficacy, limiting HCC treatment to chemotherapy. We designed and synthesized a novel small molecule, SCT-1015, that allosterically activated adenosine monophosphate-activated protein kinase (AMPK) to suppress the aerobic glycolysis in HCC. SCT-1015 was shown to bind the AMPK α and β-subunit interface, thereby exposing the kinase α domain to the upstream kinases, resulting in the increased AMPK activity. SCT-1015 dramatically reduced HCC cell growth in vitro and tumor growth in vivo. We further found that AMPK formed protein complexes with hypoxia-inducible factor 1-alpha (HIF1α) and that SCT-1015-activated AMPK promoted hydroxylation of HIF1α (402P and 564P), resulting in HIF1α degradation by the ubiquitin-proteasome system. With declined HIF1α abundance, many glycolysis-related enzymes were downregulated, suppressing aerobic glycolysis, and promoting oxidative phosphorylation. These results indicated that SCT-1015 channeled HCC cells into an unfavorable metabolic status. Overall, we reported SCT-1015 as a direct activator of AMPK signaling that held therapeutic potential in HCC.

Phytochemical Studies, Antioxidant Potential, and Identification of Bioactive Compounds Using GC-MS of the Ethanolic Extract of Luffa cylindrica (L.) Fruit

Luffa cylindrica (L.) is a medicinal plant associated with Cucurbitaceae family which is also known as loofah/sponge gourd, comprising a series of phytochemicals such as chlorophylls, carotenoids, oleanolic acid, saponin, and triterpenoids. The study was carried out to investigate and characterize the bioactive components of ethanolic extract of L. cylindrica. Whole fruit of L. cylindrica was collected, shade dried, pulverized, and extracted successively with ethanol by Soxhlet percolation technique. The crude extracts were later exposed to gas chromatography-mass spectrometry analysis. The profile of the extracts was analyzed for a wide range of secondary metabolites and characterized spectroscopically. A total of 18 components were identified in the ethanolic extract respectively. Prevailing pharmacologically active compounds benzaldehyde, 2-hydroxy-4-methyl-, 4-acetoxy-2-azetidinone, N-decanoic acid, oxirane,2-butyl-3-methyl-, cis, and 3,4-furandiol, tetrahydro-, cis- were present. The extracted compounds were articulated by comparing their retention time and peak area besides the interpretation of mass spectra. Thus, the current study reveals the presence of promising, bioactive components which in turn provides a strength to explore biological activity. In silico molecular docking could be performed for Alzheimer receptors and studied for its activity. Nevertheless, additional studies are required to carry out its bioactivity exploration and toxicity profile.

The metabolic basis of epilepsy

The brain is a highly energy-demanding organ and requires bioenergetic adaptability to balance normal activity with pathophysiological fuelling of spontaneous recurrent seizures, the hallmark feature of the epilepsies. Recurrent or prolonged seizures have long been known to permanently alter neuronal circuitry and to cause excitotoxic injury and aberrant inflammation. Furthermore, pathological changes in bioenergetics and metabolism are considered downstream consequences of epileptic seizures that begin at the synaptic level. However, as we highlight in this Review, evidence is also emerging that primary derangements in cellular or mitochondrial metabolism can result in seizure genesis and lead to spontaneous recurrent seizures. Basic and translational research indicates that the relationships between brain metabolism and epileptic seizures are complex and bidirectional, producing a vicious cycle that compounds the deleterious consequences of seizures. Metabolism-based treatments such as the high-fat, antiseizure ketogenic diet have become mainstream, and metabolic substrates and enzymes have become attractive molecular targets for seizure prevention and recovery. Moreover, given that metabolism is crucial for epigenetic as well as inflammatory changes, the idea that epileptogenesis can be both negatively and positively influenced by metabolic changes is rapidly gaining ground. Here, we review evidence that supports both pathophysiological and therapeutic roles for brain metabolism in epilepsy.

Medium chain triglycerides (MCT): State-of-the-art on chemistry, synthesis, health benefits and applications in food industry

Medium chain triglycerides (MCT) are esters of fatty acids with 6 to 12 carbon atom chains. Naturally, they occur in various sources; their composition and bioactivity are source and extraction process-linked. The molecular size of MCT oil permits unique metabolic pathways and energy production rates, making MCT oil a high-value functional food. This review details the common sources of MCT oil, presenting critical information on the various approaches for MCT oil extraction or synthesis. Apart from conventional techniques, non-thermal processing methods that show promising prospects are analyzed. The biological effects of MCT oil are summarized, and the range of need-driven modification approaches are elaborated. A section is devoted to highlighting the recent trends in the application of MCT oil for food, nutraceuticals, and allied applications. While much is debated about the role of MCT oil in human health and wellness, there is limited information on daily requirements, impact on specific population groups, and effects of long-term consumption. Nonetheless, several studies have been conducted and continue to identify the most effective methods for MCT oil extraction, processing, handling, and storage. A knowledge gap exists and future research must focus on technology packages for scalability and sustainability.

Dictyostelium discoideum: A Model System for Neurological Disorders

Background: The incidence of neurological disorders is increasing due to population growth and extended life expectancy. Despite advances in the understanding of these disorders, curative strategies for treatment have not yet eventuated. In part, this is due to the complexities of the disorders and a lack of identification of their specific underlying pathologies. Dictyostelium discoideum has provided a useful, simple model to aid in unraveling the complex pathological characteristics of neurological disorders including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, neuronal ceroid lipofuscinoses and lissencephaly. In addition, D. discoideum has proven to be an innovative model for pharmaceutical research in the neurological field. Scope of review: This review describes the contributions of D. discoideum in the field of neurological research. The continued exploration of proteins implicated in neurological disorders in D. discoideum may elucidate their pathological roles and fast-track curative therapeutics.

Ketogenic Diet Therapy for Drug-Resistant Epilepsy and Cognitive Impairment in Children With Tuberous Sclerosis Complex

OBJECTIVE

Tuberous sclerosis complex (TSC) is a rare disease with a high risk of epilepsy and cognitive impairment in children. Ketogenic diet (KD) therapy has been consistently reported to be beneficial to TSC patients. In this study, we aimed to investigate the efficacy and safety of KD in the treatment of drug-resistant epilepsy and cognitive impairment in children with TSC.

METHODS

In this multicenter study, 53 children (33 males and 20 females) with drug-resistant epilepsy or cognitive impairment caused by TSC were retrospectively recruited from 10 hospitals from January 1, 2010, to December 31, 2020. Intention-to-treat analysis was used to evaluate seizure reduction and cognition improvement as outcomes after KD therapy.

RESULTS

Of the 53 TSC patients included, 51 failed to be seizure-free with an average of 5.0 (range, 4-6) different anti-seizure medications (ASMs), before KD therapy. Although the other two patients achieved seizure freedom before KD, they still showed psychomotor development delay and electroencephalogram (EEG) abnormalities. At 1, 3, 6, and 12 months after the KD therapy, 51 (100%), 46 (90.2%), 35 (68.6%), and 16 patients (31.4%) remained on the diet therapy, respectively. At these time points, there were 26 (51.0%), 24 (47.1%), 22 (43.1%) and 13 patients (25.5%) having ≥50% reductions in seizure, including 11 (21.6%), 12 (23.5%), 9 (17.6%) and 3 patients (5.9%) achieving seizure freedom. In addition, of 51 patients with psychomotor retardation, 36 (36 of 51, 70.6%) showed cognitive and behavioral improvements. During the KD therapy, no serious side effects occurred in any patient. The most common side effects were gastrointestinal disturbance (20 of 53, 37.7%) and hyperlipidemia (6 of 53, 11.3%). The side effects were gradually relieved after adjustment of the ketogenic ratio and symptomatic treatment.

CONCLUSION

KD is an effective and safe treatment for TSC-related drug-resistant epilepsy and cognitive impairment in children. KD can reduce seizure frequency and may potentially improve cognition and behavior.

The Ketogenic Effect of Medium-Chain Triacylglycerides

Medium-chain triacylglycerides (MCTs) are dietary supplements that can induce ketosis without the need for a traditional ketogenic diet or prolonged fasting. They have the potential to marginally delay the progression of neurodegenerative diseases, such as Alzheimer's disease. However, there have been inconsistencies in reports of the MCT dose–response relationship, which may be due to differences in MCT composition, participant characteristics, and other factors that can influence ketone generation. To resolve these discrepancies, we reviewed studies that investigated the ketogenic effect of MCTs in healthy adults. Aside from the treatment dose, other factors that can influence the ketogenic response, such as accompanying meals, fasting duration, and caffeine intake, were assessed. Based on the available literature, four practical recommendations are made to optimize the ketogenic effect of MCTs and reduce unwanted side effects (primarily gastrointestinal discomfort and diarrhea). First, the starting dose should be either 5 g of octanoic acid [caprylic acid (C8); a component of MCTs] or 5 g of a combination of C8 and decanoic or capric acid (C10; another component of MCTs), and the dose should be progressively increased to 15–20 g of C8. Second, MCTs should be consumed after an overnight fast, without an accompanying meal if tolerable, or with a low-carbohydrate meal. Third, the addition of caffeine may slightly increase the ketogenic response. Fourth, emulsifying the MCTs might increase their ketogenic effect and alleviate side effects.

Possible Involvement of the Nutrient and Energy Sensors mTORC1 and AMPK in Cell Fate Diversification in a Non-Metazoan Organism

mTORC1 and AMPK are mutually antagonistic sensors of nutrient and energy status that have been implicated in many human diseases including cancer, Alzheimer’s disease, obesity and type 2 diabetes. Starved cells of the social amoeba Dictyostelium discoideum aggregate and eventually form fruiting bodies consisting of stalk cells and spores. We focus on how this bifurcation of cell fate is achieved. During growth mTORC1 is highly active and AMPK relatively inactive. Upon starvation, AMPK is activated and mTORC1 inhibited; cell division is arrested and autophagy induced. After aggregation, a minority of the cells (prestalk cells) continue to express much the same set of developmental genes as during aggregation, but the majority (prespore cells) switch to the prespore program. We describe evidence suggesting that overexpressing AMPK increases the proportion of prestalk cells, as does inhibiting mTORC1. Furthermore, stimulating the acidification of intracellular acidic compartments likewise increases the proportion of prestalk cells, while inhibiting acidification favors the spore pathway. We conclude that the choice between the prestalk and the prespore pathways of cell differentiation may depend on the relative strength of the activities of AMPK and mTORC1, and that these may be controlled by the acidity of intracellular acidic compartments/lysosomes (pHv), cells with low pHv compartments having high AMPK activity/low mTORC1 activity, and those with high pHv compartments having high mTORC1/low AMPK activity. Increased insight into the regulation and downstream consequences of this switch should increase our understanding of its potential role in human diseases, and indicate possible therapeutic interventions.

Moving the Research Forward: The Best of British Biology Using the Tractable Model System Dictyostelium discoideum

The social amoeba Dictyostelium discoideum provides an excellent model for research across a broad range of disciplines within biology. The organism diverged from the plant, yeast, fungi and animal kingdoms around 1 billion years ago but retains common aspects found in these kingdoms. Dictyostelium has a low level of genetic complexity and provides a range of molecular, cellular, biochemical and developmental biology experimental techniques, enabling multidisciplinary studies to be carried out in a wide range of areas, leading to research breakthroughs. Numerous laboratories within the United Kingdom employ Dictyostelium as their core research model. This review introduces Dictyostelium and then highlights research from several leading British research laboratories, covering their distinct areas of research, the benefits of using the model, and the breakthroughs that have arisen due to the use of Dictyostelium as a tractable model system.

Decanoic Acid Stimulates Autophagy in D. discoideum

Ketogenic diets, used in epilepsy treatment, are considered to work through reduced glucose and ketone generation to regulate a range of cellular process including autophagy induction. Recent studies into the medium-chain triglyceride (MCT) ketogenic diet have suggested that medium-chain fatty acids (MCFAs) provided in the diet, decanoic acid and octanoic acid, cause specific therapeutic effects independent of glucose reduction, although a role in autophagy has not been investigated. Both autophagy and MCFAs have been widely studied in Dictyostelium, with findings providing important advances in the study of autophagy-related pathologies such as neurodegenerative diseases. Here, we utilize this model to analyze a role for MCFAs in regulating autophagy. We show that treatment with decanoic acid but not octanoic acid induces autophagosome formation and modulates autophagic flux in high glucose conditions. To investigate this effect, decanoic acid, but not octanoic acid, was found to induce the expression of autophagy-inducing proteins (Atg1 and Atg8), providing a mechanism for this effect. Finally, we demonstrate a range of related fatty acid derivatives with seizure control activity, 4BCCA, 4EOA, and Epilim (valproic acid), also function to induce autophagosome formation in this model. Thus, our data suggest that decanoic acid and related compounds may provide a less-restrictive therapeutic approach to activate autophagy.

Disentangling Mitochondria in Alzheimer's Disease

Alzheimer's disease (AD) is a major cause of dementia in older adults and is fast becoming a major societal and economic burden due to an increase in life expectancy. Age seems to be the major factor driving AD, and currently, only symptomatic treatments are available. AD has a complex etiology, although mitochondrial dysfunction, oxidative stress, inflammation, and metabolic abnormalities have been widely and deeply investigated as plausible mechanisms for its neuropathology. Aβ plaques and hyperphosphorylated tau aggregates, along with cognitive deficits and behavioral problems, are the hallmarks of the disease. Restoration of mitochondrial bioenergetics, prevention of oxidative stress, and diet and exercise seem to be effective in reducing Aβ and in ameliorating learning and memory problems. Many mitochondria-targeted antioxidants have been tested in AD and are currently in development. However, larger streamlined clinical studies are needed to provide hard evidence of benefits in AD. This review discusses the causative factors, as well as potential therapeutics employed in the treatment of AD.

The WIPI Gene Family and Neurodegenerative Diseases: Insights From Yeast and Dictyostelium Models

WIPIs are a conserved family of proteins with a characteristic 7-bladed β-propeller structure. They play a prominent role in autophagy, but also in other membrane trafficking processes. Mutations in human WIPI4 cause several neurodegenerative diseases. One of them is BPAN, a rare disease characterized by developmental delay, motor disorders, and seizures. Autophagy dysfunction is thought to play an important role in this disease but the precise pathological consequences of the mutations are not well established. The use of simple models such as the yeast Saccharomyces cerevisiae and the social amoeba Dictyostelium discoideum provides valuable information on the molecular and cellular function of these proteins, but also sheds light on possible pathways that may be relevant in the search for potential therapies. Here, we review the function of WIPIs as well as disease-causing mutations with a special focus on the information provided by these simple models.

Using Dictyostelium to Advance Our Understanding of the Role of Medium Chain Fatty Acids in Health and Disease

Ketogenic diets have been utilized for many years to improve health, and as a dietary approach for the treatment of a range of diseases, where the mechanism of these low carbohydrate and high fat diets is widely considered to be through the production of metabolic products of fat breakdown, called ketones. One of these diets, the medium chain triglyceride ketogenic diet, involves high fat dietary intake in the form of medium chain fatty acids (MCFAs), decanoic and octanoic acid, and is commonly used in endurance and high intensity exercises but has also demonstrated beneficial effects in the treatment of numerous pathologies including drug resistant epilepsy, cancer, and diabetes. Recent advances, using Dictyostelium discoideum as a model, have controversially proposed several direct molecular mechanisms for decanoic acid in this diet, independent of ketone generation. Studies in this model have identified that decanoic acid reduces phosphoinositide turnover, diacylglycerol kinase (DGK) activity, and also inhibits the mechanistic target of rapamycin complex 1 (mTORC1). These discoveries could potentially impact the treatment of a range of disorders including epilepsy, cancer and bipolar disorder. In this review, we summarize the newly proposed mechanisms for decanoic acid, identified using D. discoideum, and highlight potential roles in health and disease treatment.

Astrocyte metabolism of the medium-chain fatty acids octanoic acid and decanoic acid promotes GABA synthesis in neurons via elevated glutamine supply

The medium-chain fatty acids octanoic acid (C8) and decanoic acid (C10) are gaining attention as beneficial brain fuels in several neurological disorders. The protective effects of C8 and C10 have been proposed to be driven by hepatic production of ketone bodies. However, plasma ketone levels correlates poorly with the cerebral effects of C8 and C10, suggesting that additional mechanism are in place. Here we investigated cellular C8 and C10 metabolism in the brain and explored how the protective effects of C8 and C10 may be linked to cellular metabolism. Using dynamic isotope labeling, with [U-¹³C]C8 and [U-¹³C]C10 as metabolic substrates, we show that both C8 and C10 are oxidatively metabolized in mouse brain slices. The ¹³C enrichment from metabolism of [U-¹³C]C8 and [U-¹³C]C10 was particularly prominent in glutamine, suggesting that C8 and C10 metabolism primarily occurs in astrocytes. This finding was corroborated in cultured astrocytes in which C8 increased the respiration linked to ATP production, whereas C10 elevated the mitochondrial proton leak. When C8 and C10 were provided together as metabolic substrates in brain slices, metabolism of C10 was predominant over that of C8. Furthermore, metabolism of both [U-¹³C]C8 and [U-¹³C]C10 was unaffected by etomoxir indicating that it is independent of carnitine palmitoyltransferase I (CPT-1). Finally, we show that inhibition of glutamine synthesis selectively reduced ¹³C accumulation in GABA from [U-¹³C]C8 and [U-¹³C]C10 metabolism in brain slices, demonstrating that the glutamine generated from astrocyte C8 and C10 metabolism is utilized for neuronal GABA synthesis. Collectively, the results show that cerebral C8 and C10 metabolism is linked to the metabolic coupling of neurons and astrocytes, which may serve as a protective metabolic mechanism of C8 and C10 supplementation in neurological disorders.

Dietary medium chain triglycerides for management of epilepsy: New data from human, dog, and rodent studies

Many studies show that glucose metabolism in epileptic brain areas can be impaired. Energy is crucial to maintain normal brain function, including ion and neurotransmitter balances. Energy deficits can lead to disruption of ion gradients, which can trigger neuronal depolarization and generation of seizures. Thus, perturbed metabolic processing of glucose in epileptogenic brain areas indicates a specific nutritional need for people and animals with epilepsy, as they are likely to benefit from auxiliary brain fuels other than glucose. Ketogenic diets provide the ketone bodies acetoacetate and β-hydroxybutyrate, which can be used as auxiliary fuel by the brain. In approximately 50% children and adults with certain types of epilepsy, who can tolerate and maintain these dietary regimens, seizure frequency can be effectively reduced. More recent data demonstrate that addition of medium chain triglycerides (MCTs), which provide the medium chain fatty acids octanoic and decanoic acid, as well as ketone bodies as auxiliary brain energy, can be beneficial in rodent seizure models, and dogs and humans with epilepsy. Here, this evidence is reviewed, including tolerance in 65% of humans, efficacy studies in dogs, possible anticonvulsant mechanisms of actions of MCTs, and specifically decanoic acid as well as metabolic and antioxidant mechanisms. In conclusion, MCTs are a promising adjunct to standard pharmacological treatment for both humans and dogs with epilepsy, as they lack central nervous system side effects found with current antiepileptic drugs. There is now a need for larger clinical trials in children, adults, and dogs to find the ideal composition and doses of MCTs and the types of epilepsy that respond best.

Review of the treatment options for epilepsy in tuberous sclerosis complex: towards precision medicine

Tuberous sclerosis complex (TSC) is a rare genetic disorder caused by mutations in the TSC1 or TSC2 genes, which encode proteins that antagonise the mammalian isoform of the target of rapamycin complex 1 (mTORC1) - a key mediator of cell growth and metabolism. TSC is characterised by the development of benign tumours in multiple organs, together with neurological manifestations including epilepsy and TSC-associated neuropsychiatric disorders (TAND). Epilepsy occurs frequently and is associated with significant morbidity and mortality; however, the management is challenging due to the intractable nature of the seizures. Preventative epilepsy treatment is a key aim, especially as patients with epilepsy may be at a higher risk of developing severe cognitive and behavioural impairment. Vigabatrin given preventatively reduces the risk and severity of epilepsy although the benefits for TAND are inconclusive. These promising results could pave the way for evaluating other treatments in a preventative capacity, especially those that may address the underlying pathophysiology of TSC, including everolimus, cannabidiol and the ketogenic diet (KD). Everolimus is an mTOR inhibitor approved for the adjunctive treatment of refractory TSC-associated seizures that has demonstrated significant reductions in seizure frequency compared with placebo, improvements that were sustained after 2 years of treatment. Highly purified cannabidiol, recently approved in the US as Epidiolex® for TSC-associated seizures in patients ⩾1 years of age, and the KD, may also participate in the regulation of the mTOR pathway. This review focusses on the pivotal clinical evidence surrounding these potential targeted therapies that may form the foundation of precision medicine for TSC-associated epilepsy, as well as other current treatments including anti-seizure drugs, vagus nerve stimulation and surgery. New future therapies are also discussed, together with the potential for preventative treatment with targeted therapies. Due to advances in understanding the molecular genetics and pathophysiology, TSC represents a prototypic clinical syndrome for studying epileptogenesis and the impact of precision medicine.

Phytocannabinoid-dependent mTORC1 regulation is dependent upon inositol polyphosphate multikinase activity

BACKGROUND AND PURPOSE

Cannabidiol (CBD) has been shown to differentially regulate the mechanistic target of rapamycin complex 1 (mTORC1) in preclinical models of disease, where it reduces activity in models of epilepsies and cancer and increases it in models of multiple sclerosis (MS) and psychosis. Here, we investigate the effects of phytocannabinoids on mTORC1 and define a molecular mechanism.

EXPERIMENTAL APPROACH

A novel mechanism for phytocannabinoids was identified using the tractable model system, Dictyostelium discoideum. Using mouse embryonic fibroblasts, we further validate this new mechanism of action. We demonstrate clinical relevance using cells derived from healthy individuals and from people with MS (pwMS).

KEY RESULTS

Both CBD and the more abundant cannabigerol (CBG) enhance mTORC1 activity in D. discoideum. We identify a mechanism for this effect involving inositol polyphosphate multikinase (IPMK), where elevated IPMK expression reverses the response to phytocannabinoids, decreasing mTORC1 activity upon treatment, providing new insight on phytocannabinoids' actions. We further validated this mechanism using mouse embryonic fibroblasts. Clinical relevance of this effect was shown in primary human peripheral blood mononuclear cells, where CBD and CBG treatment increased mTORC1 activity in cells derived from healthy individuals and decreased mTORC1 activity in cells derived from pwMS.

CONCLUSION AND IMPLICATIONS

Our findings suggest that both CBD and the abundant CBG differentially regulate mTORC1 signalling through a mechanism dependent on the activity of the upstream IPMK signalling pathway, with potential relevance to the treatment of mTOR-related disorders, including MS.