Th17 cell-mediated immune response in a subpopulation of dogs with idiopathic epilepsy

Background Canine idiopathic epilepsy (IE) is a common neurological disease with severe impact on the owner´s and the dog’s quality of life. A subpopulation of dogs with IE does not respond to antiseizure drugs (non-responder). Th17 cells (T helper cells) and their proinflammatory Interleukin-17 (IL-17) are part of the immune system and previous studies showed their involvement in the pathogenesis of several autoimmune diseases. Non-responder might have an abnormal immune response against structures of the central nervous system. To discover a new aetiology of canine IE and thereby optimising the therapy of intractable IE, this prospective study aimed to investigate Th17 cells and IL-17 in dogs with IE. The underlying hypothesis was that in some dogs with IE a Th17 cell-mediated immune response could be detectable. Methods 57 dogs with IE and 10 healthy dogs (control group, C) were enrolled in the study. EDTA blood was taken to measure Th17 cells by flow cytometry. IL-17 was measured in 35 cerebrospinal fluid (CSF) and 33 serum samples using an enzyme-linked immunosorbent assay (ELISA). It was investigated whether there was a significant increase of stimulated Th17 cells in blood samples or of IL-17 in serum and CSF samples of dogs with IE in comparison to C. Correlations between the amount of Th17 cells/μL or IL-17 and different clinical parameters e.g. seizure frequency, seizure type, seizure severity or treatment response were evaluated. Additionally, Th17 cells/μL were randomly controlled of 17 dogs with IE and were examined for changes over time and in relation to treatment response. Results Ten dogs with IE had strongly elevated stimulated Th17 cells/μL within the blood (>100 Th17 cells/μL). A slight positive correlation between stimulated Th17 cells/μL and seizure severity (p = 0.046; rSpear = 0.27) was proven in these dogs. In addition, 4/10 dogs with elevated Th17 levels experienced cluster seizures and status epilepticus in comparison to 9% of the dogs with non-elevated Th17 levels (<100 Th17 cells/μL). Dogs with IE had significantly higher IL-17 values in CSF and serum samples compared to C (p<0.001; p<0.002; respectively). Conclusion In single dogs with IE, strongly increased amounts of Th17 cells were detectable and dogs with elevated Th17 cells seemed to have a greater risk for experiencing a combination of cluster seizures and status epilepticus. Therefore, an underlying Th17-cell mediated immune response was suspected and hence anti-inflammatory drugs could be indicated in these single cases with intractable epilepsy.

Evaluation of the Anticonvulsant Activities of Gastrodia Elata Bl.- Acorus Tatarinowii Decoction on Experimentally Induced Seizures in Mice

Epilepsy is a serious public health problem in the world. At present, the effect of drug treatment of epilepsy is are not satisfactory. Medicinal plants as pharmaceuticals and for healthcare treatments in the management of epilepsy in China for many centuries. Especially, Gastrodia elata Bl.-Acorus tatarinowii, as a classic and important herb pairs in folk medicine, has been used in folk medicine to control seizures. However, the animal experiment data of its anticonvulsant effect is limited in the literature. The objective of this study was to mainly analyze the anticonvulsant activity of Gastrodia elata-Acorus tatarinowii (GEAT) decoction in maximal electroshock (MES), pentylenetetrazole (PTZ) and trimercaptopropionic acid (3-MP) induced seizures in mice, providing scientific basis for the treatment of convulsive disorders in traditional medicine. In addition, the improvement effect were examined on seizure severity, anxiety, cognitive dysfunction, inflammation and oxidative stress in PTZ kindled mice. The results showed that GEAT decoction dose-dependently protected mice against MES, 3-MP and PTZ induced acute seizures. Meanwhile, GEAT decoction ameliorated seizure severity, decreased the accumulation of inflammatory mediators TNF-α, IL-1β, and IL-6, mitigated oxidative stress, as well as alleviated anxious-like behavior and cognitive deficits in PTZ-kindled mice. Our data evidenced that the anticonvulsant properties attributed to GEAT decoction as adjunctive therapy for epileptic patients in folk medicine.

Dual Targeting by Inhibition of Phosphoinositide-3-Kinase and Mammalian Target of Rapamycin Attenuates the Neuroinflammatory Responses in Murine Hippocampal Cells and Seizures in C57BL/6 Mice

Emerging evidence suggests the association of seizures and inflammation; however, underlying cell signaling mechanisms are still not fully understood. Overactivation of phosphoinositide-3-kinases is associated with both neuroinflammation and seizures. Herein, we speculate the PI3K/Akt/mTOR pathway as a promising therapeutic target for neuroinflammation-mediated seizures and associated neurodegeneration. Firstly, we cultured HT22 cells for detection of the downstream cell signaling events activated in a lipopolysaccharide (LPS)-primed pilocarpine (PILO) model. We then evaluated the effects of 7-day treatment of buparlisib (PI3K inhibitor, 25 mg/kg p.o.), dactolisib (PI3K/mTOR inhibitor, 25 mg/kg p.o.), and rapamycin (mTORC1 inhibitor, 10 mg/kg p.o.) in an LPS-primed PILO model of seizures in C57BL/6 mice. LPS priming resulted in enhanced seizure severity and reduced latency. Buparlisib and dactolisib, but not rapamycin, prolonged latency to seizures and reduced neuronal loss, while all drugs attenuated seizure severity. Buparlisib and dactolisib further reduced cellular redox, mitochondrial membrane potential, cleaved caspase-3 and p53, nuclear integrity, and attenuated NF-κB, IL-1β, IL-6, TNF-α, and TGF-β1 and TGF-β2 signaling both in vitro and in vivo post-PILO and LPS+PILO inductions; however, rapamycin mitigated the same only in the PILO model. Both drugs protected against neuronal cell death demonstrating the contribution of this pathway in the seizure-induced neuronal pyknosis; however, rapamycin showed resistance in a combination model. Furthermore, LPS and PILO exposure enhanced pAkt/Akt and phospho-p70S6/total-p70S6 kinase activity, while buparlisib and dactolisib, but not rapamycin, could reduce it in a combination model. Partial rapamycin resistance was observed possibly due to the reactivation of the pathway by a functionally different complex of mTOR, i.e., mTORC2. Our study substantiated the plausible involvement of PI3K-mediated apoptotic and inflammatory pathways in LPS-primed PILO-induced seizures and provides evidence that its modulation constitutes an anti-inflammatory mechanism by which seizure inhibitory effects are observed. We showed dual inhibition by dactolisib as a promising approach. Targeting this pathway at two nodes at a time may provide new avenues for antiseizure therapies.

The severity of seizures and epileptiform activity index in the assessment of antiepileptic treatment efficacy in patients with generalized tonic-clonic awakening seizures

Objective: to evaluate the role of seizure severity and epileptiform activity index (IEA) assessment in newly-diagnosed idiopathic generalized epilepsy with generalized tonic-clonic awakening seizures (GTCS).Material and methods. The study included 31 patients with newly-diagnosed generalized epilepsy with GTCS aged 14–52 years (mean age 25.06±9.3 years), which were divided into two groups depending on seizure severity: Group 1 (n=9, 29%) with <18 points, and Group 2 (n=22, 71%) with ≥18 points. Seizure severity was analysed by using National Hospital Seizure Severity Scale (NHS3). All patients underwent video-electroencephalography monitoring (8–24 hours) with IEA assessment at baseline and at 1, 3, 6 and 12 months after the beginning of treatment. Therapeutic efficacy was assessed using the criteria of seizure absence (medically induced remission), seizure rate decrease by >50% (responders), seizure rate decrease by <50% (insufficient efficacy), seizure rate increase and retention in treatment.Results. Total EAI at baseline was significantly higher in patients from Group 2 (p=0.019). Despite markedly reduced EAI level in both groups, in Group 1 (less than 18 points by NHS3) EAI was significantly lower compared to Group 2 (≥18 points) at all subsequent visits: visit 2 (p=0.038), visit 3 (p=0.035), visit 4 (p=0.047), and visit 5 (p=0.022).Conclusions. Assessing seizure severity may become an additional objective criterion while evaluating treatment efficacy.

New Insights Into the Anticonvulsant Effects of Essential Oil From Melissa officinalis L. (Lemon Balm)

Melissa officinalis L. is used in traditional European and Iranian folk medicines to treat a plethora of neurological diseases including epilepsy. We utilized the in vitro and in vivo models of epilepsy to probe the anticonvulsant potentials of essential oil from M. officinalis (MO) to gain insight into the scientific basis for its applications in traditional medicine for the management of convulsive disorders. MO was evaluated for effects on maximal electroshock (MES) and pentylenetetrazole (PTZ) -induced seizures in mice, on 4–aminopyridine (4-AP)-brain slice model of epilepsy and sustained repetitive firing of current clamped neurons; and its ameliorative effects were examined on seizure severity, anxiety, depression, cognitive dysfunction, oxidative stress and neuronal cell loss in PTZ-kindled rats. MO reversibly blocked spontaneous ictal-like discharges in the 4-AP-brain slice model of epilepsy and secondary spikes from sustained repetitive firing, suggesting anticonvulsant effects and voltage-gated sodium channel blockade. MO protected mice from PTZ– and MES–induced seizures and mortality, and ameliorated seizure severity, fear-avoidance, depressive-like behavior, cognitive deficits, oxidative stress and neuronal cell loss in PTZ–kindled rats. The findings warrant further study for the potential use of MO and/or its constituent(s) as adjunctive therapy for epileptic patients.