Neuroprotective Effects Of Ketogenic Diet Research Articles

Ameliorating effect of ketogenic diet on acute status epilepticus: Insights into biochemical and histological changes in rat hippocampus.

This study aimed to evaluate the potential neuroprotective effects of ketogenic diet (KD) against the neuronal disruptions induced by SE in lithium-pilocarpine rat model of status epilepticus (SE). Four groups of female rats include; groups I and III received standard diet and groups II and IV received KD for 3 weeks. Groups I and II were left untreated, while groups III and IV were injected with LiCl (127 mg/kg, i.p.) followed by pilocarpine HCl (10mg/kg, i.p.) 18-24h later, repeatedly, till induction of SE. 72 h post-SE, KD effectively ameliorated the balance between excitatory (glutamate) and inhibitory (GABA) neurotransmitters and the oxidative stress indices, increased adenine nucleotides and decreased immunoreactivity of iNOS, TNFα, glial fibrillary acidic protein, and synaptophysin. Thiswas in association with improvement in inflammatory response and neuronal tissue characteristics in hippocampus of SE rats. Histological changes showed preservation of neuronal integrity. These findings highlight the protective effects of KD in the acute phase post-SE via ameliorating biochemical and histological changes involved. PRACTICAL APPLICATIONS: Epilepsy is the fourth most common neurological disorder that requires lifelong treatment. It stigmatizes patients and their families. The use of the ketogenic diet (KD) as a therapy for epilepsy developed from observations that fasting could reduce seizures. From 1920s, the KD was a common epilepsy treatment until it was gradually superseded by anticonvulsant drugs so that by the 1980s it was rarely used. However, there has been a resurgence of interest and usage of the KD for epilepsy since the turn of the century. Despite its long history, the mechanisms by which KD exhibits its anti-seizure action are not fully understood. Our study aims to identify the mechanism of KD which may help further studies to achieve the same benefits with a drug or supplement to overcome its unpalatability and gastrointestinal side effects.

Ketogenic diet as elective treatment in patients with drug-unresponsive hyperinsulinemic hypoglycemia caused by glucokinase mutations

BackgroundHyperinsulinemic hypoglycemia (HI) is the most frequent cause of recurrent hypoglycemia in children. Despite diagnostic and therapeutic advances, it remains an important cause of morbidity, leading to neurological complications, such as psychomotor retardation and epilepsy. Patients with diffuse drug-unresponsive HI manifest neurological impairment and neurobehavioral problems, even though surgically treated with a near-total pancreatectomy. Based on the analogies between HI and GLUT1 deficiency, both presenting with neuroglycopenia and lack of alternative cerebral energy sources, we administered a ketogenic diet (KD) in three drug-unresponsive GCK-HI patients with the aim of preserving neurodevelopment and avoiding the need of a near-total pancreatectomy. They presented recurrent symptomatic hypoglycemia, intellectual disability and refractory epilepsy. Patients were treated with classical KD for 79, 27 and 18 months, respectively.ResultsAll patients became asymptomatic in a few days and showed an important improvement of the alert state. Epilepsy disappeared and no appearance of novel hypoglycemic lesions was detected with a brain MRI. Cognitive and adaptive abilities rapidly improved and normalized. IQ rose significantly from 81 to 111 (p = 0.04) in patient 1, from 82 vs 95 (p = 0.04) in patient 2, from 60 to 90 (p = 0.04) in patient 3.ConclusionsWe demonstrated the safety and efficacy of KD in the treatment of drug-unresponsive GCK-HI at a short and long-term. The neuroprotective effects of KD determined the recovery from epilepsy and intellectual disabilities and averted the need of a near-total pancreatectomy. All patients and their families reported an improvement of physical and psychosocial well-being, with a substantial improvement of their quality of life. These results might change the course and the quality of life of these patients and their families, having a relevant impact on human lives. Therefore, KD might be considered the elective treatment in unresponsive forms of GCK-HI.

Cuprizone-Induced Demyelination in Mouse Hippocampus Is Alleviated by Ketogenic Diet.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Recently, ketogenic diet (KD) supplementation has attracted great interest. Therefore, we established the cuprizone (CPZ)-induced demyelination mouse model to investigate the possible neuroprotective effect of KD on the hippocampus of mice. We found that KD significantly elevated the level of serum β-hydroxybutyric acid, improved behavioral and motor abnormalities, and impaired the spatial learning and memory of CPZ-induced demyelination mice. Meanwhile, KD lessened the hippocampal demyelination by enhancing the expression of mature oligodendrocytes (OLs), which was revealed by the elevated expression of MBP and CNPase, as well as the luxol fast blue-staining intensity. Furthermore, KD inhibits the activation of microglia (especially M1-like microglia) and reactive astrocytes. Interestingly, KD attenuated the CPZ-induced oxidative stress by decreasing the malondialdehyde (MDA) content and restoring the glutathione (GSH) levels. In addition, the double immunofluorescence staining revealed that KD enhanced the expression of SIRT1 in astrocytes, microglia, and mature oligodendrocytes. Concomitantly, Western blot demonstrated that KD increased the expression of SIRT1, phosphorylated-AKT, mTOR, and PPAR-γ. In conclusion, KD exerted a neuroprotective effect on CPZ-induced demyelination mice, and this activity was associated with the modulation of the SIRT1/PPAR-γ and SIRT1/P-Akt/mTOR pathways.

Ketogenic diet attenuates neuronal injury via autophagy and mitochondrial pathways in pentylenetetrazol-kindled seizures

Autophagy alterations have been observed in a variety of neurological disorders, however, very few studies have focused on autophagy alterations in epilepsy. The ketogenic diet (KD) likely ameliorates neuronal loss in several seizure models. However, whether this neuroprotective function occurs via starvation-induced autophagy and its prevalence in chronic kindled seizures remains unknown. The aim of this study was to determine the role of autophagy following seizure under KD, and the potential mechanism involved. Pentylenetetrazol (PTZ)-kindled rats, which were fed a Normal diet (ND) or KD, were pretreated with intraventricular infusions of saline, autophagy inducer rapamycin (RAP), or inhibitor 3-methyladenine (3-MA). KD alleviated seizure severity, decreased the number of Fluoro-jade B (FJB)-positive cells in the hippocampus of kindled rats. These effects were abolished by 3-MA pretreatment. RAP pretreatment did not affect seizure severity, but decreased the number of FJB-positive cells in ND group. KD decreased the percentage of damaged mitochondria in kindled group. Hippocampal Beclin-1 was increased by KD in vehicle group. The autophagy proteins Atg5, Beclin-1 and the ratio of microtubule-associated protein 1 light chain 3 (LC3) II to LC3-I in kindled KD-fed rats were higher, and the autophagy substrate P62 was lower than those in the kindled ND-fed rats, indicating an increase in autophagy following KD. Pretreatment with RAP increased the level of LC3-II/LC3-I, and pretreatment with 3-MA increased the level of P62 in KD-fed rats. To further clarify the mechanism of autophagy protection, the levels of key mitochondria related molecules were examed. The results showed that mitochondrial cytochrome c was up-regulated, cytosolic cytochrome c and the downstream cleaved caspase-3 was down-regulated in KD-fed rats, indicating a decrease in mitochondrial apoptosis. Taken together, our results indicated that KD activates autophagic pathways and reduces brain injury during PTZ-kindled seizures. The neuroprotective effect of KD is likely exerted via a reduction of mitochondrial cytochrome c release.

Effects of ketogenic diet on neurobehavioral damages and expression of ZIP7 in cerebral cortex of rat following recurrent neonatal seizures

Objective To explore the intervention effect of ketogenic diet (KD) on neurobehavioral damages after flurothyl-induced neonatal recurrent seizures in rats and on the expression of ZIP7. Methods Postnatal day 8 SD rats (n=24) were divided into four groups randomly: normal group (NS+ ND group), non-seizure and ketogenic diet group (NS+ KD group), seizure and normal diet group (RS+ ND group), seizure and ketogenic diet group (RS+ KD group), n=6 in each group. At postnatal day 31, the grip-strength test and open field test were monitored. At postnatal day 32, rats were sacrificed and the expression of ZIP7 protein level in cerebral cortex was detected with Western blot. Results (1) The grip-strength test: compared with NS+ ND group ((32.67±2.42) s), the time needed to hold on glass bar in RS+ ND group ((19.17±2.48) s) was shorter significantly (P<0.05). Compared with RS+ ND group, the time needed to hold on glass bar in RS+ KD group ((26.25±2.87) s) was significantly longer (P<0.05). (2) Open field test: compared with NS+ ND group ((2.00±0.63) times), the times of grooming in RS+ ND group ((4.00±0.63) times) were more (P<0.05). Compared with RS+ ND group, the times of grooming in the RS+ KD group ((2.17±0.75) times) were fewer (P<0.05). (3)Western blot: compared with NS+ ND group, the level of ZIP7 of the RS+ ND group in cerebral cortex were lower (P<0.05). Compared with RS+ ND group, the level of ZIP7 of the RS+ KD group in cerebral cortex were higher (P<0.05). Conclusion Neonatal recurrent seizures may damage neurobehavior, and the neuroprotective effects of ketogenic diet may be associated with the increasing of ZIP7 in cerebral cortex. Key words: Ketogenic diet; Neonatal seizure; Neurobehavior; ZIP7

Sciatic nerve regeneration in rats subjected to ketogenic diet

Objectives: Ketogenic diet (KD) is a high-fat-content diet with insufficiency of carbohydrates that induces ketogenesis. Besides its anticonvulsant properties, many studies have shown its neuroprotective effect in central nervous system, but its influence on peripheral nervous system has not been studied yet. We examined the influence of KD on regeneration of peripheral nerves in adult rats.Methods: Fifty one rats were divided into three experimental (n = 15) and one control (n = 6) groups. Right sciatic nerve was crushed and animals were kept on standard (ST group) or ketogenic diet, the latter was introduced 3 weeks before (KDB group) or on the day of surgery (KDA group). Functional (CatWalk) tests were performed once a week, and morphometric (fiber density, axon diameter, and myelin thickness) analysis of the nerves was made after 6 weeks. Body weight and blood ketone bodies level were estimated at the beginning and the end of experiment.Results: Functional analysis showed no differences between groups. Morphometric evaluation showed most similarities to the healthy (uncrushed) nerves in KDB group. Nerves in ST group differed mostly from all other groups. Ketone bodies were elevated in both KD groups, while post-surgery animals’ body weight was lower as compared to ST group.Discussion: Regeneration of sciatic nerves was improved in KD – preconditioned rats. These results suggest a neuroprotective effect of KD on peripheral nerves.

Effect and mechanism of ketogenic diet on neurobehavioral demages induced by recurrent neonatal seizures

Objective To investigate the intervention effect of ketogenic diet (KD) on neurobehavioral demages after flurothyl-induced recurrent neonatal seizures in rats and on the expression of ApoE. Methods Postnatal day 8 (P8) SD rats (quantity: 48) were randomly divided into two groups: the non-seizure group (NS group, n=24) and the recurrent-seizure group (RS group, n=24). From P9, rats in RS group were subjected to recurrent seizures induced by volatile flurothyl 30 min each day for consecutive 8 days. While rats in NS group were placed into the container for an equal amount of time to their counterpart without exposuring to flurothyl. At P28, each group was divided into two groups again: non-seizure and normal diet group(NS+ ND group, n=12), non-seizure and ketogenic diet group(NS+ KD group, n=12), recurrent-seizure and normal diet group(RS+ ND group, n=12), recurrent-seizure and ketogenic diet group(RS+ KD group, n=12). At P42, neurodevelopmental indicators were monitored. ApoE protein levels in cerebral cortex were determined by western blot at P58. Results Neurodevelopmental indicators were analyzed at P42: in the plane righting experiment, the rats of group NS+ ND (1.0±0.14) about the time of plane righting was significant different comparing with group RS+ ND ((0.75±0.32)s)(P 0.05). In the negative geotaxis reaction experiment, the rats of groups NS+ KD and RS+ ND((3.17±0.58)s, (6.75±0.75)s) about the time of negative geotaxis reaction were significant different comparing with group NS+ ND ((1.58±0.52)s)(P<0.05). Compared with group RS+ ND, the group RS+ KD in the time of negative geotaxis reaction was obviously shortened(P<0.05). In the cliff avoidance test, there were significant differences between group NS+ ND、RS+ KD ((5.75±2.90)s, (9.50±4.36)s)and group RS+ ND((14.00±4.79)s) about the time of cliff avoidance(P<0.05). In western blot, the expression of ApoE in cerebral cortex in the RS+ ND group (1.26±0.30) was obviously increased compared with group NS+ ND (0.78±0.12) (P<0.05), and there had also significant difference between group RS+ KD (0.89±0.10) and group RS+ ND(P<0.05). Conclusion The neuroprotective effects of ketogenic diet on recurrent neonatal seizure-induced neurobehavioral demages may be associated with the reduction of ApoE in cerebral cortex. Key words: Neonatal seizure; Ketogenic diet; Neurobehavior; ApoE

Intracisternal administration of glibenclamide or 5-hydroxydecanoate does not reverse the neuroprotective effect of ketogenic diet against ischemic brain injury-induced neurodegeneration

Primary objective: To investigate the role of ATP-sensitive potassium (KATP) channels in the neuroprotective effects of a ketogenic diet against cardiac arrest-induced cerebral ischemic brain injury-induced neurodegeneration.Research design: Male Sprague Dawley rats were randomly divided into three groups and were fed with a ketogenic diet for 25 days before being subjected to a cardiac arrest-induced cerebral ischemia for 8 minutes 30 seconds. Four hours before cardiac arrest-induced cerebral ischemia, one group was intracisternally injected with glibenclamide, a plasma membrane KATP channel blocker. The second group was injected with 5-hydroxydecanoate, a mitochondrial KATP channel blocker. The third group was without the pre-treatment with KATP channel antagonist. Nine days after the cardiac arrest, rats were sacrificed. Fluoro-jade (FJ) staining was used to evaluate cerebral ischemic neurodegeneration in the rat brain sections.Main outcomes and results: The number of FJ-positive degenerating neurons in the CA1 area of the hippocampus, the cerebellum and the thalamic reticular nucleus of the ketogenic diet-fed rats with or without glibenclamide or 5-hydroxydecanoate pre-treatment before cardiac arrest-induced cerebral ischemia is zero.Conclusions: The results suggest that KATP channels do not play a significant role in the neuroprotective effects of the ketogenic diet against cardiac arrest-induced cerebral ischemic injury-induced neurodegeneration.