Does ghrelin level change after epileptic seizure in rats?

Evaluation of the Effect of Parenting Style and Parental Mealtime Actions on the Eating Behavior of Children with Epilepsy

BACKGROUND

Research on the interaction of parenting style, parents' mealtime behaviors, and children's eating behavior in the presence of chronic disease is limited. This study aimed to investigate the impact of parenting style and parental mealtime actions on the eating behavior of children with epilepsy.

METHODS

Thirty-one children with epilepsy, thirty-one healthy children (aged 4-9 years), and their parents were included. The Multidimensional Assessment of Parenting Scale (MAPS), Parent Mealtime Action Scale, Children's Eating Behavior Questionnaire, and Healthy Eating Index (HEI)-2015 were applied. The MAPS, HEI-2015 scores, and body mass index for age Z scores were similar in both groups (p > 0.05). In the epilepsy group, the food approach behavior score was higher, and positive correlations were noted between broadband negative parenting and food approach behavior, and the HEI-2015 score and broadband positive parenting (p < 0.05). Regression analysis showed that broadband negative parenting and snack modeling increased the food approach behavior in the epilepsy group. Owing to the chronic disease, the effects of parent-child interaction on the child's eating behavior in the epilepsy group differed from those of healthy children reported in the literature.

Evaluation of repeated ghrelin administration on seizures, oxidative stress and neurochemical parameters in pentyleneterazole induced kindling in rats

Introduction: Epileptic seizures are thought to be caused by the impaired balance between excitatory (glutamate) and inhibitor [gamma amino butyric acid (GABA)] neurotransmitters in the brain. Neuropeptides have potent modulator properties on these neurotransmitters.Objective: Ghrelin exerts anticonvulsant effects in an acute pentylenetetrazole (PTZ) model. However, the effect of repeated ghrelin injections in chronic pentylenetetrazole kindling model is not known. In this study, the effects of repeated ghrelin administration on seizure scores, working memory, locomotor activity, oxidative biomarkers, and neurochemical parameters in PTZ kindling in rats was examined.Methods: For this purpose, 35 mg/kg of PTZ was administered intraperitoneally to the experimental groups. The rats also received physiological saline/diazepam or ghrelin before each PTZ injection. After behavioural analysis (Y-maze, rotarod, and locomotor activity tests), biochemical and neurochemical analyses were conducted using ELISA.Results: PTZ administration induced progression in the seizure scores and all of the rats in the PS + PTZ group were kindled with the 20th injection. Ghrelin treatment significantly reduced the seizure scores. The difference among the groups in terms of the Y-maze, locomotor activity, and rotarod tests was nonsignificant. PTZ administration significantly decreased the brain GABA, CAT, and AChE levels, and increased the MDA, NO, and protein carbonyl levels. Repeated ghrelin treatment ameliorated the GABA, AChE, CAT, MDA, NO, and protein carbonyl levels.Conclusion: Taken together, the results indicated that repeated ghrelin treatment had antioxidant, and anticonvulsant activity on PTZ kindling in rats.

Down regulation of the hippocampal ghrelin receptor type-1a during electrical kindling-induced epileptogenesis

Numerous studies have shown that the ghrelin hormone is involved in epileptic conditions. However, the profile of ghrelin or its functional receptor mRNAs in seizure-susceptible brain areas was not assessed during epileptogenesis. Here, we measured the expression levels of the hippocampal ghrelin or its receptor mRNAs during electrical kindling-induced epileptogenesis. The study was conducted on twenty adult male Wistar rats. One tri-polar and two uni-polar electrodes were stereotaxically implanted in the baso-lateral amygdala or skull surface, respectively. Animals were divided into four groups, consisting of two sham groups (sham1 and sham2), and two other groups, which were partially or fully kindled. After the establishment of partial or full kindling, the hippocampi of the animals and that of the corresponding sham groups were removed. A quantitative real-time PCR technique was used to measure the expression levels of ghrelin or its functional receptor mRNAs. The results indicated that the expression levels of ghrelin did not alter in either of the partially or fully kindled rats compared to the corresponding sham groups. Ghrelin receptor (ghrelinR) down regulated, significantly in the fully-kindled rats, compared to sham2 group. Meanwhile, the mRNA expression levels of ghrelinR did not change in partially-kindled rats compared to sham1 group. The outcomes of the current study highlight the crucial, unknown impact of the hippocampal ghrelinR through the development of electrical kindling epileptogenesis, and points out the importance of ghrelinR as a goal to adjust epileptogenic progression.

Antagonism of the ghrelin receptor type 1a in the rat brain induces status epilepticus in an electrical kindling model of epilepsy

Studies have shown the anti-seizure properties of the ghrelin hormone in different models of epilepsy. Nevertheless, the role of the endogenous ghrelin is unknown in the electrical kindling model of epilepsy. In this study, we evaluated the effect of the antagonism of the ghrelin receptors in the brain of fully kindled rats. Adult male Wistar rats weighing 300 g were used. Animals were stereotaxically implanted with two uni-polar electrodes in the skull surface and a tri-polar electrode in the basolateral amygdala, and a guide cannula in the left lateral ventricle. Animals underwent a rapid kindling protocol. After showing three consecutive stages of five seizures, the animals were considered fully kindled. D-Lys-3-GHRP-6 (1, 50, and 100 μg/rat) was injected intracerebroventricularly (i.c.v.) in the kindled animals. Each rat was considered as its control and received a single dose of D-Lys-3-GHRP-6. Seizure parameters including after discharge duration (ADD), seizure stage (SS), stage four latency (S4L), and stage five duration (S5D) were recorded. The paired t test indicated a significant increase in seizure induction. D-Lys-3-GHRP-6 (1 μg/rat; i.c.v.) prolonged ADD in the kindled rats, significantly. D-Lys-3-GHRP-6 (50 and 100 μg/rat; i.c.v.) induced spontaneous seizures, which led to status epilepticus in the kindled rats. The results indicate that the antagonism of the ghrelin functional receptors prolongs seizures and induces status epilepticus in the kindling model of epilepsy, and propose that the endogenous ghrelin signaling has crucial antiepileptic properties.

Targeting the Ghrelin Receptor as a Novel Therapeutic Option for Epilepsy

Epilepsy is a neurological disease affecting more than 50 million individuals worldwide. Notwithstanding the availability of a broad array of antiseizure drugs (ASDs), 30% of patients suffer from pharmacoresistant epilepsy. This highlights the urgent need for novel therapeutic options, preferably with an emphasis on new targets, since “me too” drugs have been shown to be of no avail. One of the appealing novel targets for ASDs is the ghrelin receptor (ghrelin-R). In epilepsy patients, alterations in the plasma levels of its endogenous ligand, ghrelin, have been described, and various ghrelin-R ligands are anticonvulsant in preclinical seizure and epilepsy models. Up until now, the exact mechanism-of-action of ghrelin-R-mediated anticonvulsant effects has remained poorly understood and is further complicated by multiple downstream signaling pathways and the heteromerization properties of the receptor. This review compiles current knowledge, and discusses the potential mechanisms-of-action of the anticonvulsant effects mediated by the ghrelin-R.

Serum and urine ghrelin in adult epileptic patients

Background

Several neuropeptides have concerned with epilepsy pathogenesis; ghrelin showed an anticonvulsant effect. There is a potential relation between its level and antiepileptic drug (AEDs) response.

Objective

To evaluate ghrelin effect in adult epileptic patients and in response to AEDs.

Materials and methods

This case control study included 40 adult epileptic patients and 40 healthy controls. Participants were subjected to history taking of seizure semiology, full general and neurological examination, electroencephalography, and cranial imaging. Fasting serum acylated ghrelin (AG), unacylated ghrelin (UAG), and urine AG levels were estimated to all participants by enzyme-linked immunosorbent assay (ELIZA).

Results

Serum AG, UAG, and urine AG levels were statistically higher in epileptic patients than controls (p = 0.005, 0.003, and 0.018 respectively). A significant higher level of serum AG was found among generalized epileptic patients (p = 0.038). There was higher statistically significant levels of all measured parameters among poly therapy patients (p = 0.003, 0.013, and 0.001 respectively). Also, a higher statistical significant level of serum AG and UAG in AEDs-responsive patients was found (p < 0.001). Our results demonstrated significant positive correlation between all measured parameters (serum AG, UAG, and urine AG) and epilepsy duration (p = 0.001, 0.002, and 0.009 respectively). High serum AG and UAG levels were independently associated with longer epilepsy duration (p = 0.00 and 0.008) and better response to AEDs (p < 0.001).

Conclusion

These results indicated that serum AG and UAG levels were significantly high in epileptic patients especially with prolonged epilepsy duration and good AEDs response.

Trial registration

ClinicalTrials.gov NCT03926273 (22-04-2019) “retrospectively registered.”

Obestatin improves oxidative brain damage and memory dysfunction in rats induced with an epileptic seizure

Obestatin was shown to alleviate renal, gastrointestinal and haemorrhage-induced brain injury in rats. In order to investigate the neuroprotective effects of obestatin on seizure-induced oxidative brain injury, an epileptic seizure was induced with a single intraperitoneal (i.p.) dose of pentylenetetrazole (PTZ, 45mg/kg) in male Wistar rats. Thirty minutes before the PTZ injection, rats were treated with either saline or obestatin (1μg/kg, i.p.). Seizure was video-taped and then evaluated by using Racine's scoring (0-5). For the assessment of memory function, passive-avoidance test was performed before seizure induction, which was repeated on the 3rd day of seizure. The rats were decapitated at the 24th or 72nd hour of seizures and brain tissues were obtained for histopathological examination and for measuring levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen radicals and myeloperoxidase (MPO) activity. Obestatin treatment reduced the average seizure score, decreased the occurrence and duration of generalized tonic-clonic seizures, presenting with a shorter latency to their onset. Increased lipid peroxidation and enhanced generation of oxygen-derived radicals detected at the post-seizure 72nd h were suppressed by the consecutive treatments of obestatin, but no changes were observed by the single obestatin treatment in the 24-h seizure group. Neuronal damage and increased GFAP immunoreactivity, observed in the hippocampal areas and cortex of PTZ-induced rats were alleviated in 3-day obestatin-treated PTZ group. PTZ-induced memory dysfunction was significantly improved in obestatin-treated PTZ group as compared to saline-treated rats. The present data indicate that obestatin ameliorated the severity of PTZ-induced seizures, improved memory dysfunction and reduced neuronal damage by limiting oxidative damage.

Interictal ghrelin levels in adult patients with epilepsy

PURPOSE

In vitro or in animal models of epilepsy, ghrelin showed a clear anticonvulsant action, whose mechanisms are somewhat obscure. In humans however, a controversial relation exists between ghrelin and epilepsy. Yet most studies investigated just total ghrelin levels, without a proper distinction between acylated (AG) or unacylated ghrelin (UAG). We thus evaluated separately AG and UAG interictal levels in adult patients with epilepsy, and their relation to clinical features.

METHOD

Cross-sectional study in a tertiary referral centre. Fifty-six patients were recruited: 19 with idiopathic generalized epilepsy, 18 with cryptogenic focal epilepsy and 19 with symptomatic focal epilepsy. Twenty-six healthy subjects of similar age, sex and body mass index (BMI) acted as controls. AG and UAG levels were measured following an overnight fasting and contrasted to the clinical and biometric features.

RESULTS

AG and UAG levels were similar between patients and controls. The AG/UAG ratio was higher in patients, also when weighted for covariates (age, BMI, gender, and drugs). Splitting patients according to their epileptic syndrome, drug-resistance or antiepileptic drug number/type resulted in no significant difference in AG, UAG or their ratio. Yet, AG and UAG levels were positively predicted by disease duration, independently by confounders.

CONCLUSION

In adult patients with epilepsy, interictal ghrelin levels did not differ from controls, though the AG/UAG ratio was imbalanced. Interpretation of the latter phenomenon is uncertain. Further, levels of AG and UAG were in direct proportion to disease duration, which may represent a long-term compensatory mechanism, antagonistic to the epileptic process.

Neuroactive peptides as putative mediators of antiepileptic ketogenic diets

Various ketogenic diet (KD) therapies, including classic KD, medium chain triglyceride administration, low glycemic index treatment, and a modified Atkins diet, have been suggested as useful in patients affected by pharmacoresistant epilepsy. A common goal of these approaches is to achieve an adequate decrease in the plasma glucose level combined with ketogenesis, in order to mimic the metabolic state of fasting. Although several metabolic hypotheses have been advanced to explain the anticonvulsant effect of KDs, including changes in the plasma levels of ketone bodies, polyunsaturated fatty acids, and brain pH, direct modulation of neurotransmitter release, especially purinergic (i.e., adenosine) and γ-aminobutyric acidergic neurotransmission, was also postulated. Neuropeptides and peptide hormones are potent modulators of synaptic activity, and their levels are regulated by metabolic states. This is the case for neuroactive peptides such as neuropeptide Y, galanin, cholecystokinin, and peptide hormones such as leptin, adiponectin, and growth hormone-releasing peptides (GHRPs). In particular, the GHRP ghrelin and its related peptide des-acyl ghrelin are well-known controllers of energy homeostasis, food intake, and lipid metabolism. Notably, ghrelin has also been shown to regulate the neuronal excitability and epileptic activation of neuronal networks. Several lines of evidence suggest that GHRPs are upregulated in response to starvation and, particularly, in patients affected by anorexia and cachexia, all conditions in which also ketone bodies are upregulated. Moreover, starvation and anorexia nervosa are accompanied by changes in other peptide hormones such as adiponectin, which has received less attention. Adipocytokines such as adiponectin have also been involved in modulating epileptic activity. Thus, neuroactive peptides whose plasma levels and activity change in the presence of ketogenesis might be potential candidates for elucidating the neurohormonal mechanisms involved in the beneficial effects of KDs. In this review, we summarize the current evidence for altered regulation of the synthesis of neuropeptides and peripheral hormones in response to KDs, and we try to define a possible role for specific neuroactive peptides in mediating the antiepileptic properties of diet-induced ketogenesis.

Neuropeptides as targets for the development of anticonvulsant drugs

Epilepsy is a common neurological disorder characterized by recurrent seizures. These seizures are due to abnormal excessive and synchronous neuronal activity in the brain caused by a disruption of the delicate balance between excitation and inhibition. Neuropeptides can contribute to such misbalance by modulating the effect of classical excitatory and inhibitory neurotransmitters. In this review, we discuss 21 different neuropeptides that have been linked to seizure disorders. These neuropeptides show an aberrant expression and/or release in animal seizure models and/or epilepsy patients. Many of these endogenous peptides, like adrenocorticotropic hormone, angiotensin, cholecystokinin, cortistatin, dynorphin, galanin, ghrelin, neuropeptide Y, neurotensin, somatostatin, and thyrotropin-releasing hormone, are able to suppress seizures in the brain. Other neuropeptides, such as arginine-vasopressine peptide, corticotropin-releasing hormone, enkephalin, β-endorphin, pituitary adenylate cyclase-activating polypeptide, and tachykinins have proconvulsive properties. For oxytocin and melanin-concentrating hormone both pro- and anticonvulsive effects have been reported, and this seems to be dose or time dependent. All these neuropeptides and their receptors are interesting targets for the development of new antiepileptic drugs. Other neuropeptides such as nesfatin-1 and vasoactive intestinal peptide have been less studied in this field; however, as nesfatin-1 levels change over the course of epilepsy, this can be considered as an interesting marker to diagnose patients who have suffered a recent epileptic seizure.

NPY Receptors Blockade Prevents Anticonvulsant Action of Ghrelin in the Hippocampus of Rat

PURPOSE

Ghrelin has been shown to have antiepileptic function. However, the underlying mechanisms by which, ghrelin exerts its antiepileptic effects are still unclear. In the present study, we investigated whether neuropeptide Y (NPY) mediates ghrelin anticonvulsant effect in the brain through its Y1, Y2 or Y5 receptors.

METHODS

Male Wistar rats were bilaterally microinjected with ghrelin 0.3 nmol/μl/side and NPY antagonists; GR231118 (Y1 receptor antagonist), BIIE0246 (Y2 receptor antagonist), CGP71683 (Y5 receptor antagonist) or solvents (Saline, DMSO) into the dorsal hippocampus 20 minutes before ghrelin administration. Thirty minutes after ghrelin microinjection, a single convulsive dose of pentylenetetrazole (PTZ) (50 mg/kg) was injected intraperitoneally (ip). Afterwards, duration of seizure and total seizure score (TSS) were assessed for 30 minutes in all animals.

RESULTS

Intrahippocampal injection of 0.3 nmol/μl/side ghrelin decreased duration of seizure and TSS induced by PTZ. The suppression of both duration (p<0.001) and TSS (p<0.001) induced by ghrelin in hippocampus were significantly blocked by GR231118 (10 μg/μl/side), BIIE0246 (400 pmol/μl/side) and CGP 71683A (5 nmol/μl/side).

CONCLUSION

Our findings suggest that NPY Y1, Y2 and Y5 receptors in the hippocampus may somehow mediate the anticonvulsive action of ghrelin. Therefore, it is possible to speculate that ghrelin acts in the hippocampus to modulate seizures via NPY.

Time-dependent changes in the serum levels of prolactin, nesfatin-1 and ghrelin as a marker of epileptic attacks young male patients

A relationship between hormones and seizures has been reported in animals and humans. Therefore, the purpose of this study was to investigate the association between serum levels of prolactin, nesfatin-1 and ghrelin measured different times after a seizure or non-epileptic event and compared with controls. The study included a total of 70 subjects, and of whom 18 patients had secondary generalized epilepsy (SGE), 16 patients had primary generalized epilepsy (PGE), 16 patients exhibited paroxysmal event (psychogenic) and 20 healthy males were control subjects. The first sample was taken within 5min of a seizure, with further samples taken after 1, 24, and 48h so long as the patient did not exhibit further clinically observable seizures; blood samples were taken once from control subjects. Prolactin was measured immediately using TOSOH Bioscience hormone assays. Nesfatin-1 and ghrelin peptides were measured using a commercial immunoassay kit. Patients suffering from focal epilepsy with secondary generalization and primary generalized epilepsy presented with significantly higher levels of serum prolactin and nesfatin-1 and lower ghrelin levels 5min, 1 and 24h after a seizure than patients presenting with paroxysmal events (psychogenic) and control subjects; the data were similar but not statistically significant after 48h. The present study suggests that increased serum prolactin and nesfatin-1 concentrations, decreased ghrelin concentrations could be used as markers to identify patients that have suffered a recent epileptic seizure or other paroxysmal event (psychogenic).