D2 dopamine receptor-mediated mechanisms of dopaminergic system modulation in in vivo and in vitro experimental models of migraine.

The dopaminergic system is implicated in the pathophysiology of migraine. However, the underlying mechanisms remain unclear. We explored the effects and mechanisms of dopaminergic system modulation in the in vivo and in vitro rat models of migraine. Dopaminergic agonist apomorphine, D2 receptor antagonists metoclopramide and haloperidol and 5-HT3 receptor antagonist ondansetron alone and together were tested in nitroglycerin-induced migraine model, in vivo. Likewise, the combinations of drugs were also tested on basal calcitonin gene-related peptide (CGRP) release in vitro hemiskull preparations. Mechanical allodynia was tested by von Frey filaments. CGRP concentrations in trigeminovascular structures and in vitro superfusates and c-Fos levels in the brainstem were determined by enzyme-linked immunosorbent assay. Meningeal mast cells were evaluated with toluidine blue staining. Apomorphine further enhanced nitroglycerin-induced mechanical allodynia, brainstem c-fos expression, trigeminal ganglion and brainstem CGRP concentrations and meningeal mast cell degranulation, in vivo. Haloperidol completely antagonised all apomorphine-induced effects and also alleviated changes induced by nitroglycerin without apomorphine. Metoclopramide and ondansetron partially attenuated apomorphine- or nitroglycerin-induced effects. A combination of haloperidol and ondansetron decreased basal CGRP release, in vitro, whereas the other administrations were ineffective. Apomorphine-mediated dopaminergic activation exacerbated nitroglycerin-stimulated nociceptive reactions by further enhancing c-fos expression, CGRP release and mast cell degranulation in strategical structures associated with migraine pain. Metoclopramide partially attenuated the effects of apomorphine, most likely because it is also a 5-HT3 receptor antagonist. Haloperidol with pure D2 receptor antagonism feature appears to be more effective than metoclopramide in reducing migraine-related parameters in dopaminergic activation- and/or NTG-induced migraine-like conditions.

Plasma levels of neurogenic inflammation related neuropeptides in pediatric patients with community-acquired pneumonia and their potential diagnostic value in distinguishing viral and bacterial pneumonia.

Neurogenic inflammation is involved in the development and progression of respiratory inflammatory diseases. However, its role in community-acquired pneumonia (CAP) remains unclear. We therefore aimed to investigate plasma levels of neurogenic inflammation-related neuropeptides, calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY), and procalcitonin (PCT) in pediatric patients with CAP and to assess their diagnostic value in viral and bacterial/mixed pneumonia. A total of 124 pediatric patients with CAP (1 month-18 years old) and 56 healthy children of similar ages were prospectively enrolled. The patients were classified as viral (n = 99) and bacterial/mixed (n = 25) pneumonia. Plasma levels of the peptides were quantified by ELISA. ROC analysis was performed to evaluate possible diagnostic value of the peptides. While plasma levels of CGRP, VIP and PCT were significantly higher in patients with CAP than in the control group, respectively, NPY levels were significantly lower. Moreover, plasma levels of all neuropeptides and PCT were significantly higher in bacterial pneumonia patients compared to viral pneumonia patients. ROC analysis revealed that CGRP, SP and NPY had a diagnostic value in distinguishing viral and bacterial/mixed pneumonia. CONCLUSIONS: Our findings suggest that these neuropeptides may be implicated in pediatric CAP. CGRP, SP and NPY together may be a promising candidate in distinguishing viral and bacterial/mixed pneumonia, however, for this, further studies are needed. WHAT IS KNOWN: • Neurogenic inflammation contributes to the development and progression of respiratory inflammatory diseases such as chronic obstructive pulmonary disease and bronchial asthma. WHAT IS NEW: • Plasma levels of neurogenic inflammation related neuropeptides calcitonin gene-related peptide, substance P, vasoactive intestinal peptide and neuropeptide Y are changed in pediatric community-acquired pneumonia. Calcitonin gene-related peptide, substance P and neuropeptide Y are promising candidates in distinguishing viral and bacterial/mixed pneumonia.

Mitochondrial metabolism related markers GDF-15, FGF-21, and HIF-1α are elevated in pediatric migraine attacks.

OBJECTIVE: The purpose of this study was to investigate the serum levels of mitochondrial metabolism/reactive oxygen species (ROS)-related peptides (hypoxia inducible factor-1α [HIF-1α], fibroblast growth factor-21 [FGF-21], growth differentiation factor-15 [GDF-15]) and key migraine-related neuropeptides (calcitonin gene-related peptide [CGRP], pituitary adenylate cyclase-activating peptide-38 [PACAP-38], substance P [SP], and vasoactive intestinal peptide [VIP]) during migraine attacks and to evaluate their diagnostic value in pediatric migraine. BACKGROUND: There is increasing evidence for the important role of impairment in oxidative mitochondrial metabolism in the pathophysiology of migraine. Potential biomarkers that may reflect the relationship between migraine and mitochondrial dysfunction are unclear. METHODS: A total of 68 female pediatric migraine patients without aura and 20 female healthy controls aged 8-18 years, admitted to the hospital, were enrolled in this cross-sectional study. Serum concentrations of these molecules were determined by enzyme-linked immunosorbent assays, and clinical features and their possible diagnostic value were analyzed. RESULTS: Serum levels of HIF-1α (252.4 ± 51.9 [mean ± standard deviation]) pg/mL), GDF-15 (233.7 ± 24.7 pg/mL), FGF-21 (96.1 ± 13.1 pg/mL), CGRP (44.5 ± 11.3), and PACAP-38 (504.7 ± 128.9) were significantly higher in migraine patients compared to healthy controls (199.8 ± 26.8, 192.8 ± 20.7, 79.3 ± 4.1, 34.1 ± 3.5 and 361.2 ± 86.3 pg/mL, respectively). The serum levels of these peptides were also higher in patients with chronic migraine than in patients with episodic migraine, and higher in the ictal period than in the interictal period. A positive correlation was found between attack frequency and both HIF-1α and FGF-21 levels in migraine patients. Serum levels of VIP and SP were not different between the migraine patients and healthy controls. CONCLUSION: Migraine attacks are accompanied by elevated HIF-1α, FGF-21, GDF-15, CGRP, and PACAP-38 in medication-naive pediatric patients with migraine. Elevated circulating mitochondrial metabolism/ROS-related peptides suggest a mitochondrial stress in pediatric migraine attacks and may have potential diagnostic value in monitoring disease progression and treatment response in children. Novel approaches intervening with mitochondrial metabolism need to be investigated.

Meningeal mast cell-mediated mechanisms of cholinergic system modulation in neurogenic inflammation underlying the pathophysiology of migraine.

Growing evidence indicates that the parasympathetic system is implicated in migraine headache. However, the cholinergic mechanisms in the pathophysiology of migraine remain unclear. We investigated the effects and mechanisms of cholinergic modulation and a mast cell stabilizer cromolyn in the nitroglycerin-induced in vivo migraine model and in vitro hemiskull preparations in rats. Effects of cholinergic agents (acetylcholinesterase inhibitor neostigmine, or acetylcholine, and muscarinic antagonist atropine) and mast cell stabilizer cromolyn or their combinations were tested in the in vivo and in vitro experiments. The mechanical hyperalgesia was assessed by von Frey hairs. Calcitonin gene-related peptide (CGRP) and C-fos levels were measured by enzyme-linked immunosorbent assay. Degranulation and count of meningeal mast cells were determined by toluidine-blue staining. Neostigmine augmented the nitroglycerin-induced mechanical hyperalgesia, trigeminal ganglion CGRP levels, brainstem CGRP, and C-fos levels, as well as degranulation of mast cells in vivo. Atropine inhibited neostigmine-induced additional increases in CGRP levels in trigeminal ganglion and brainstem while it failed to do this in the mechanical hyperalgesia, C-fos levels, and the mast cell degranulation. However, all systemic effects of neostigmine were abolished by cromolyn. The cholinergic agents or cromolyn did not alter basal release of CGRP, in vitro, but cromolyn alleviated the CGRP-inducing effect of capsaicin while atropine failed to do it. These results ensure for a first time direct evidence that endogenous acetylcholine contributes to migraine pathology mainly by activating meningeal mast cells while muscarinic receptors are involved in CGRP release from trigeminal ganglion and brainstem, without excluding the possible role of nicotinic cholinergic receptors.

Therapeutic effects of carvacrol on beta-amyloid-induced impairments in in vitro and in vivo models of Alzheimer's disease.

Due to the complex nature of Alzheimer's disease (AD), it is important to investigate agents with multiple effects in the treatment of AD. Carvacrol possesses anti-acetylcholinesterase, anti-oxidant, and neuroprotective properties. We therefore investigated therapeutic effects of carvacrol on cell viability, oxidative stress, and cognitive impairment in Aß1-42-induced in vitro and in vivo models of AD. SH-SY5Y cells differentiated into neurons by retinoic acid were pretreated with carvacrol or galantamine before Aß1-42 administration. For in vivo experiments, a rat model of AD was established by bilateral intrahippocampal injection of Aß1-42. The groups received 1% DMSO, carvacrol, or galantamine intraperitoneally twice a day (morning and afternoon) for 6 days. Cell viability was determined using MTT and LDH tests. Learning and memory functions were assessed using a passive-avoidance test. Oxidant-antioxidant parameters (MDA, H2 O2 , SOD, and CAT) and Tau, Aß1-40, and Aß1-42 peptide levels in in vitro supernatant or in vivo serum and hippocampal samples were measured using ELISA. Carvacrol increased cell viability and exhibited a protective effect against oxidative stress by preventing Aß1-42-induced cytotoxicity, LDH release, and increments in MDA and H2 O2 levels in vitro. Additionally, it improved memory impairment by reversing Aß1-42-induced changes on passive-avoidance test. Carvacrol ameliorated Aß1-42-induced increments in MDA and H2 O2 levels in in vitro supernatant and in vivo hippocampal samples. However, none of the treatments changed in vitro SOD and Tau-peptide levels, or in vivo serum levels of MDA, H2 O2 , SOD, CAT, Tau peptide, Aß1-40, or Aß1-42. Our results suggest that multi-target pharmacological agent carvacrol may be promising in treatment of AD by preventing beta-amyloid-induced neurotoxicity, oxidative stress, and memory deficits.

Mast cell activation ameliorates pentylenetetrazole-induced seizures in rats: The potential role for serotonin.

Neuroinflammation plays a key role in the pathogenesis of epilepsy, but the underlying mechanisms are not well understood. Mast cells are multifunctional immune cells that are also activated by stress. The effects of activated mast cells on epileptogenesis are not yet known. This study investigated the effects and mechanisms of compound 48/80-stimulated mast cell activation on pentylenetetrazole-induced epileptic seizures in rats. Male Wistar rats were separated into seven groups (n = 12). Group-1(NS+PTZ) received intraperitoneal saline solution, while groups 2(C-48/80+PTZ-1), 3(C-48/80+PTZ-2), and 4(C-48/80+PTZ-3) received compound-48/80 at doses of 0.5, 1, and 2 mg/kg, respectively, 30 min before 45 mg/kg pentylenetetrazole administration. Similarly, Group-5(Cr+C-48/80+PTZ) received 10 mg/kg cromolyn plus 2 mg/kg compound-48/80 before pentylenetetrazole, and Group-6(MC Dep+C-48/80+PTZ) was exposed to a mast cell-depletion process, and then received 2 mg/kg compound-48/80. Group-7(5-HT+PTZ) received 10 mg/kg serotonin. Seizure stages were evaluated using Racine's scale. Compound-48/80 at 2 mg/kg induced anticonvulsive effects against pentylenetetrazole-induced seizures by extending onset-times of both myoclonic-jerk and generalized tonic-clonic seizures (p = 0.0001), and by shortening the duration of generalized tonic-clonic seizure (p = 0.008). These effects were reversed by cromolyn (p = 0.0001). These effects were not observed in mast cell-depleted rats. Similarly to compound 48/80, serotonin also exhibited anticonvulsive effects against seizures (p < 0.05). Compound 48/80 acts as an anticonvulsant by activating mast cells in a dose-dependent manner. The anticonvulsive effects of mast cell activation may be mediated by serotonin. Mast cell activation may therefore provide protective activity against seizures under appropriate circumstances.

Receptor mechanisms mediating the anti-neuroinflammatory effects of endocannabinoid system modulation in a rat model of migraine.

Calcitonin gene-related peptide (CGRP), substance P and dural mast cells are main contributors in neurogenic inflammation underlying migraine pathophysiology. Modulation of endocannabinoid system attenuates migraine pain, but its mechanisms of action remain unclear. We investigated receptor mechanisms mediating anti-neuroinflammatory effects of endocannabinoid system modulation in in vivo migraine model and ex vivo hemiskull preparations in rats. To induce acute model of migraine, a single dose of nitroglycerin was intraperitoneally administered to male rats. Moreover, isolated ex vivo rat hemiskulls were prepared to study CGRP and substance P release from meningeal trigeminal afferents. We used methanandamide (cannabinoid agonist), rimonabant (cannabinoid receptor-1 CB1 antagonist), SR144528 (CB2 antagonist) and capsazepine (transient receptor potential vanilloid-1 TRPV1 antagonist) to explore effects of endocannabinoid system modulation on the neurogenic inflammation, and possible involvement of CB1, CB2 and TRPV1 receptors during endocannabinoid effects. Methanandamide attenuated nitroglycerin-induced CGRP increments in in vivo plasma, trigeminal ganglia and brainstem and also in ex vivo hemiskull preparations. Methanandamide also alleviated enhanced number and degranulation of dural mast cells induced by nitroglycerin. Rimonabant, but not capsazepine or SR144528, reversed the attenuating effects of methanandamide on CGRP release in both in vivo and ex vivo experiments. Additionally, SR144528, but not rimonabant or capsazepine, reversed the attenuating effects of methanandamide on dural mast cells. However, neither nitroglycerin nor methanandamide changed substance P levels in both in vivo and ex vivo experiments. Methanandamide modulates CGRP release in migraine-related structures via CB1 receptors and inhibits the degranulation of dural mast cells through CB2 receptors. Selective ligands targeting CB1 and CB2 receptors may provide novel and effective treatment strategies against migraine.

The effects of certain TRP channels and voltage-gated KCNQ/Kv7 channel opener retigabine on calcitonin gene-related peptide release in the trigeminovascular system.

BACKGROUND: Calcitonin gene-related peptide release in trigeminovascular system is a pivotal component of neurogenic inflammation underlying migraine pathophysiology. Transient receptor potential channels and voltage-gated KCNQ/Kv7 potassium channels expressed throughout trigeminovascular system are important targets for modulation of calcitonin gene-related peptide release. We investigated the effects of certain transient receptor potential (TRP) channels the vanilloid 1 and 4 (TRPV1 and TRPV4), the ankyrin 1 (TRPA1), and metastatin type 8 (TRPM8), and voltage-gated potassium channel (Kv7) opener retigabine on calcitonin gene-related peptide release from peripheral (dura mater and trigeminal ganglion) and central (trigeminal nucleus caudalis) trigeminal components of rats. METHODS: The experiments were carried out using well-established in-vitro preparations (hemiskull, trigeminal ganglion and trigeminal nucleus caudalis) from male Wistar rats. Agonists and antagonists of TRPV1, TRPV4, TRPA1 and TRPM8 channels, and also retigabine were tested on the in-vitro release of calcitonin gene-related peptide. Calcitonin gene-related peptide concentrations were measured using enzyme-linked immunosorbent assay. RESULTS: Agonists of these transient receptor potential channels induced calcitonin gene-related peptide release from hemiskull, trigeminal ganglion and trigeminal nucleus caudalis, respectively. The transient receptor potential channels-induced calcitonin gene-related peptide releases were blocked by their specific antagonists and reduced by retigabine. Retigabine also decreased basal calcitonin gene-related peptide releases in all preparations. CONCLUSION: Our findings suggest that favorable antagonists of these transient receptor potential channels, or Kv7 channel opener retigabine may be effective in migraine therapy by inhibiting neurogenic inflammation that requires calcitonin gene-related peptide release.

Plasma levels of vasoactive neuropeptides in pediatric patients with migraine during attack and attack-free periods.

BACKGROUND: Increasing evidence suggests that vasoactive neuropeptides such as pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38), substance P, calcitonin gene-related peptide, and vasoactive intestinal peptide are involved in the pathophysiology of migraine in adults, but their role in pediatric migraineurs remains unclear. We prospectively investigated plasma levels of these vasoactive neuropeptides in pediatric migraine patients without aura and compared the results with those of age-matched healthy controls. METHODS: Thirty-eight children aged 6-18 years with migraine without aura and 20 age-matched control subjects were included in the study. Neuropeptides in plasma samples from the controls, and in either the ictal or interictal periods in pediatric migraine without aura, were measured using ELISA. RESULTS: PACAP-38 and vasoactive intestinal peptide levels in both ictal and interictal plasma were higher in the patients with pediatric migraine without aura than in the controls (p < 0.001), although calcitonin gene-related peptide and substance P levels remained unchanged. Otherwise, no significant difference was determined between ictal and interictal periods in terms of all neuropeptide levels. CONCLUSIONS: This study demonstrates increased plasma PACAP-38 and vasoactive intestinal peptide levels, but not calcitonin gene-related peptide and substance P levels, in pediatric patients with migraine during both attack and attack-free periods. The study findings suggest that PACAP-38 and vasoactive intestinal peptide may be implicated in the pathophysiology of migraine, particularly in pediatric migraineurs.

Effects of estrogen and progesterone on the neurogenic inflammatory neuropeptides: implications for gender differences in migraine.

Neurogenic inflammation including calcitonin gene-related peptide (CGRP) and substance-P (SP) release plays a pivotal role in migraine pathogenesis. Prevalence of migraine is ~ 3 folds higher in women than in men, but its underlying mechanisms remained unclear. We investigated the effects of female sex hormones estrogen and progesterone on CGRP and SP in in-vivo and ex-vivo in rats of both sexes. For in-vivo experiments, male, female and ovariectomized rats were separated into four groups (n = 7) as control, estrogen, progesterone and estrogen + progesterone, respectively. Groups received daily intraperitoneal vehicle, 17ß-estradiol, progesterone and 17ß-estradiol + progesterone for 5 days, respectively. For ex-vivo experiments in both sexes, isolated trigeminal ganglia and hemiskull preparations were divided into four groups (n = 6 or 8), respectively, as in-vivo groups, and administered the same test substances. CGRP and SP contents in plasma and superfusates were determined using ELISA. In in-vivo experiments, 17ß-estradiol decreased CGRP levels in males and SP levels in ovariectomized rats. Progesterone increased both CGRP and SP levels in females. Their combination decreased both CGRP and SP levels in males, and only SP levels in ovariectomized rats. In ex-vivo experiments, 17ß-estradiol reduced CGRP release in males and SP release in females in trigeminal ganglia. While progesterone increased CGRP release in trigeminal ganglia, it reduced SP release from hemiskulls in both sexes. Their combination restored progesterone-mediated changes in neuropeptides releases in both trigeminal ganglia and hemiskulls in both sexes. Estrogen alleviates neurogenic inflammation through modulation of CGRP and SP release. Progesterone has dual effects on these neuropeptides in different sites associated with migraine pain.

Salmon calcitonin ameliorates migraine pain through modulation of CGRP release and dural mast cell degranulation in rats.

The exact mechanism of migraine pathophysiology still remains unclear due to the complex nature of migraine pain. Salmon calcitonin (SC) exhibits antinociceptive effects in the treatment of various pain conditions. In this study, we explored the mechanisms underlying the analgesic effect of salmon calcitonin on migrane pain using glyceryltrinitrate (GTN)-induced model of migraine and ex vivo meningeal preparations in rats. Rats were intraperitoneally administered saline, GTN (10 mg/kg), vehicle, saline + GTN, SC (50 µg/kg) + GTN, and SC alone. Also, ex vivo meningeal preparations were applied topically 100 µmol/L GTN, 50 µmol/L SC, and SC + GTN. Calcitonin gene-related peptide (CGRP) contents of plasma, trigeminal neurons and superfusates were measured using enzyme-immunoassays. Dural mast cells were stained with toluidine blue. c-fos neuronal activity in trigeminal nucleus caudalis (TNC) sections were determined by immunohistochemical staining. The results showed that GTN triggered the increase in CGRP levels in plasma, trigeminal ganglion neurons and ex vivo meningeal preparations. Likewise, GTN-induced c-fos expression in TNC. In in vivo experiments, GTN caused dural mast cell degranulation, but similar effects were not seen in ex vivo experiments. Salmon calcitonin administration ameliorated GTN-induced migraine pain by reversing the increases induced by GTN. Our findings suggested that salmon calcitonin could alleviate the migraine-like pain by modulating CGRP release at different levels including the generation and conduction sites of migraine pain and mast cell behaviour in the dura mater. Therefore salmon calcitonin may be a new therapeutic choice in migraine pain relief.

Nucleotide homeostasis and purinergic nociceptive signaling in rat meninges in migraine-like conditions.

Extracellular ATP is suspected to contribute to migraine pain but regulatory mechanisms controlling pro-nociceptive purinergic mechanisms in the meninges remain unknown. We studied the peculiarities of metabolic and signaling pathways of ATP and its downstream metabolites in rat meninges and in cultured trigeminal cells exposed to the migraine mediator calcitonin gene-related peptide (CGRP). Under resting conditions, meningeal ATP and ADP remained at low nanomolar levels, whereas extracellular AMP and adenosine concentrations were one-two orders higher. CGRP increased ATP and ADP levels in meninges and trigeminal cultures and reduced adenosine concentration in trigeminal cells. Degradation rates for exogenous nucleotides remained similar in control and CGRP-treated meninges, indicating that CGRP triggers nucleotide release without affecting nucleotide-inactivating pathways. Lead nitrate-based enzyme histochemistry of whole mount meninges revealed the presence of high ATPase, ADPase, and AMPase activities, primarily localized in the medial meningeal artery. ATP and ADP induced large intracellular Ca(2+) transients both in neurons and in glial cells whereas AMP and adenosine were ineffective. In trigeminal glia, ATP partially operated via P2X7 receptors. ATP, but not other nucleotides, activated nociceptive spikes in meningeal trigeminal nerve fibers providing a rationale for high degradation rate of pro-nociceptive ATP. Pro-nociceptive effect of ATP in meningeal nerves was reproduced by α,ß-meATP operating via P2X3 receptors. Collectively, extracellular ATP, which level is controlled by CGRP, can persistently activate trigeminal nerves in meninges which considered as the origin site of migraine headache. These data are consistent with the purinergic hypothesis of migraine pain and suggest new targets against trigeminal pain.

Vasoactive Intestinal peptide modulates c-Fos activity in the trigeminal nucleus and dura mater mast cells in sympathectomized rats.

Neurogenic inflammation in the dura mater caused by trigeminal nociceptive activation has been implicated in the pathophysiology of migraine. Vasoactive intestinal polypeptide (VIP) is a powerful neuroprotective neuropeptide that can modulate mast cell behavior. Migraine is also associated with sympathetic insufficiency. This study investigates the effects of VIP on the number of mast cells in the dura mater and on c-Fos expression in the trigeminal nucleus of sympathectomized rats. Experiments were carried out with 32 Sprague-Dawley male rats with body weights of 200-250 g. In the sympathectomized group, the left superior cervical sympathetic ganglion was removed. In the sympathectomized + VIP group, postoperative VIP 25 ng/kg/day (0.2 ml) was administered for 5 days. In the sham group, the ganglion and nerves were exposed but not dissected. Dura maters were stained with toluidine blue, and brainstems were labeled by indirect immunohistochemistry for c-Fos. Sympathectomy significantly increased the number of mast cells in both the ipsilateral and the contralateral dura mater (P < 0.001). VIP decreased the number of mast cells in both sides of the dura mater in sympathectomized rats. VIP also decreased c-Fos expression in the ipsilateral trigeminal nucleus of sympathectomized rats (P < 0.001). In the context of an experimental superior cervical ganglionectomy model of migraine, VIP is an efficient modulator of neurogenic inflammation of the dura.

Esculetin alleviates pentylenetetrazole-induced seizures, cognitive impairment and pro-inflammatory cytokines and suppresses penicillin-induced epileptiform activity in rats.

AIMS: To investigate the effects of different doses of esculetin on epileptiform activity, behavioral seizures, memory impairment, and cortical and hippocampal NF-κB, as a mediator of pro-inflammatory gene induction, and pro-inflammatory cytokines in penicillin- and pentylenetetrazole(PTZ)-induced seizure models in rats. MAIN METHODS: Different doses of esculetin (5, 10, and 20 mg/kg), and diazepam (5 mg/kg) as a positive control, were tested in penicillin- and pentylenetetrazole(PTZ)-induced seizure models. In the PTZ model, cognitive function, behavioral seizures, and cortical and hippocampal pro-inflammatory biomarkers and survival factor was evaluated. In the penicillin model, the frequency and amplitude of electrophysiological epileptiform activity were assessed. KEY FINDINGS: In the PTZ model, the 10 mg/kg esculetin displayed anticonvulsant effects by extending onset-times of myoclonic-jerk and generalized tonic-clonic seizure, and by diminishing seizure severity and duration of generalized tonic-clonic seizure. It also ameliorated PTZ-induced cognitive impairment, and cortical and hippocampal activin-A, IL-1ß, IL-6 and NF-κB levels. In the penicillin model, the 10 mg/kg esculetin decreased the frequency of spikes without changing the amplitude of spikes. As a positive-control, diazepam reversed all changes induced by both PTZ and penicillin. SIGNIFICANCE: Esculetin exhibits anticonvulsant and memory-improving effects by alleviating the behavioral and electrophysiological characteristics of epileptic seizures. Additionally, esculetin exerts anti-neuroinflammatory actions in the PTZ-induced seizures model. Thus, esculetin may be a multi-targeted promising agent with anticonvulsant and anti-neuroinflammatory effects in the treatment of epilepsy.

Capsaicin attenuates excitotoxic-induced neonatal brain injury and brain mast cell-mediated neuroinflammation in newborn rats.

Excitotoxicity and neuroinflammation are key contributors to perinatal brain injuries. Capsaicin, an active ingredient of chili peppers, is a potent exogenous agonist for transient receptor potential vanilloid 1 receptors. Although the neuroprotective and anti-inflammatory effects of capsaicin are well-documented, its effects on excitotoxic-induced neonatal brain injury and neuroinflammation have not previously been investigated. The aim of this study was to investigate the effects of capsaicin on brain damage, brain mast cells, and inflammatory mediators in a model of ibotenate-induced excitotoxic brain injury in neonatal rats. P5 rat-pups were intraperitoneally injected with vehicle, 0.2-, 1-, and 5-mg/kg doses of capsaicin, or the NMDA (N-methyl-d-aspartate) receptor antagonist MK-801 (dizocilpine), 30 min before intracerebral injection of 10 µg ibotenate. The naive-control group received no substance administration. The rat pups were sacrificed one or five days after ibotenate injection. Levels of activin A and interleukin (IL)-1ß, IL-6, and IL-10 in brain tissue were measured using the enzyme-linked immunosorbent assay method. Cortex and white matter thicknesses, white matter lesion size, and mast cells were evaluated in brain sections stained with cresyl-violet or toluidine-blue. Capsaicin improved ibotenate-induced white matter lesions and cerebral white and gray matter thicknesses in a dose-dependent manner. In addition, it suppressed the degranulation and increased number of brain mast cells induced by ibotenate. Capsaicin also reduced the excitotoxic-induced production of neuronal survival factor activin A and of the pro-inflammatory cytokines IL-1ß, and IL-6 in brain tissue. However, IL-10 levels were not altered by the treatments. MK-801, as a positive control, reversed all these ibotenate-induced changes, further confirming the success of the model. Our findings provide, for the first time, evidence for the therapeutic effects of capsaicin against excitotoxic-induced neonatal brain injury and brain mast cell-mediated neuroinflammation. Capsaicin may therefore be a promising candidate in the prevention and/or reduction of neonatal brain damage.

Endogenous and exogenous serotonin, but not sumatriptan, ameliorate seizures and neuroinflammation in the pentylenetetrazole-induced seizure model in rats.

BACKGROUND: Epilepsy has neuropsychiatric comorbidities such as depression, bipolar disorder, and anxiety. Drugs that target epilepsy may also be useful for its neuropsychiatric comorbidities. OBJECTIVE: To investigate the effects of serotonergic modulation on pro-inflammatory cytokines and the seizures in pentylenetetrazole (PTZ)-induced seizure model in rats. METHODS: Male Wistar rats were injected intraperitoneally with serotonin, selective serotonin reuptake inhibitor fluoxetine, 5-HT1B/D receptor agonist sumatriptan, or saline 30 min prior to PTZ treatment. Behavioral seizures were assessed by the Racine's scale. Concentrations of IL-1ß, IL-6, and TNF-α in serum and brain tissue were determined by ELISA. RESULTS: Serotonin and fluoxetine, but not sumatriptan, alleviated PTZ-induced seizures by prolonging onset times of myoclonic-jerk and generalized tonic-clonic seizures. The anti-seizure effect of fluoxetine was greater than that of serotonin. Likewise, serotonin and fluoxetine, but not sumatriptan, reduced PTZ-induced increases in the levels of IL-1ß and IL-6 in both serum and brain tissue. None of the administered drugs including PTZ affected TNF-α concentrations. CONCLUSIONS: Our findings suggest that endogenous and exogenous serotonin exhibits anticonvulsant effects by suppressing the neuroinflammation. It seems that 5-HT1B/D receptors do not mediate anticonvulsant and anti-neuroinflammatory effects of serotonin.

Activation of TRESK background potassium channels by cloxyquin exerts protective effects against excitotoxic-induced brain injury and neuroinflammation in neonatal rats.

We investigated effects of activation of TRESK channels by selective activator cloxyquin on excitotoxic-induced brain injury and neuroinflammation involving brain mast cells and inflammatory cytokines in neonatal rats. Three different doses of cloxyquin (0.2, 1 and 5 mg/kg) were studied in ibotenate-induced perinatal brain injury (PBI) in P5 rat-pups. Cerebral lesions and mast cells in coronal brain sections were evaluated. Concentrations of activin A, IL-1ß, IL-6 and IL-10 in brain homogenates were measured using ELISA. Cloxyquin dose-dependently exerted protective effects against excitotoxic-induced neonatal brain injury and neuroinflammation. TRESK channels may be a promising new target for the treatment of PBIs.

Global evaluation of coronavirus disease 2019 cases and clustering of similar countries.

OBJECTIVE: It was aimed to be obtained descriptive values with respect to the outbreak time course, demographic structure, and symptom distribution by the help of case-based data, and to be compared countries by being grouped according to their similarities of outbreak indicators. METHODS: The data were obtained from open-access database. Univariate tests and cluster analysis were used to analyze the data. RESULTS: After the symptoms onset, the prolonged admission to the hospital significantly increases the risk of death. The average age and percentage of the male gender of the deceased cases were found to be significantly higher. In addition, the symptoms including fever, throat complaints, and dyspnea were determined in 70%. Countries were divided into four clusters according to their similarities in terms of three outbreak indicators. The differences among the clusters with regard to mean age, urban rate, and average of the outbreak indicators were found significant. CONCLUSION: Delaying treatment from the moment the symptoms appear will increase the risk of death and the average time to recovery or death was 2.5 weeks. It can be stated that the most important measure is to focus on methods that can detect the cases before symptoms. The indicators that have a very important role in defining the pandemic are also related to each other. Therefore, multivariate methods, which take these relationships into account, are able to produce more accurate information in determining the similarities of countries.

Protective effects of long-term probiotic mixture supplementation against pentylenetetrazole-induced seizures, inflammation and oxidative stress in rats.

Emerging evidence indicates that dysbiosis of gut microbiota plays an important role in epilepsy, although the underlying mechanisms remain unclear due to the complex nature of both microbial composition and pathophysiology of epilepsy. We investigated effects of long-term probiotics supplementation on epileptic seizures, and inflammatory and oxidant/antioxidant biomarkers in a pentylenetetrazole(PTZ)-induced seizure model in rats. Male Wistar weaner-rats were divided into four groups. The first two groups received 1 ml/day saline solution, while the other groups received 0.05 mg/1ml/day vehicle or 109cfu/1ml/day probiotic-mixture, respectively, for 60 days by gavage. Seizure was induced by a single convulsive dose of PTZ. Seizures were evaluated using Racine's scale. Concentrations of pro-inflammatory cytokines in plasma and brain tissue were determined using ELISA, while oxidant/antioxidant biomarkers were measured using an automated-colorimetric method. Probiotics supplementation exhibited anticonvulsant effects against PTZ-induced seizures by retarding onset-times of both myoclonic-jerk and generalized tonic-clonic seizure, and by shortening duration of generalized tonic-clonic seizure. Additionally, it alleviated PTZ-induced increases in levels of pro-inflammatory cytokines IL-1ß, IL-6, and IL-17A, but not of IFNγ, in plasma and brain tissue. Moreover, it restored PTZinduced fluctuations in levels of oxidants TOS and disulfide, and of antioxidants native thiol and total thiol. Our findings suggest that long-term probiotics supplementation exhibits protective effects against epileptic seizures, and alleviates (neuro)inflammation and oxidative stress related to pathophysiology of epilepsy. A probiotic-rich diet provided from childhood may provide prophylaxis against epileptic seizures, especially in susceptible individuals, as the neonate diet represents a fundamental extrinsic factor in establishing gut microbiota.

Thymoquinone Inhibits Neurogenic Inflammation Underlying Migraine Through Modulation of Calcitonin Gene-Related Peptide Release and Stabilization of Meningeal Mast Cells in Glyceryltrinitrate-Induced Migraine Model in Rats.

Two main contributors of sterile neurogenic inflammation underlying migraine pain, calcitonin gene-related peptide (CGRP), and meningeal mast cells (MMCs) play a key role in the activation of the inflammatory cascade resulting in the sensitization of trigeminal nociceptors. It is well established that phytochemical agent thymoquinone exhibits multiple anti-inflammatory effects in different in vitro and in vivo models of neuroinflammation. But its effects on the CGRP release and meningeal mast cells are unknown. In the present study, we investigated the effects of thymoquinone on the CGRP release in migraine-related strategic structures which are crucial targets for anti-migraine drugs, and on the MMCs in glyceryl trinitrate (GTN)-induced in vivo migraine model as well as in the ex vivo meningeal preparations in rats. Anti-inflammatory thymoquinone ameliorated GTN-stimulated CGRP levels in plasma, and migraine-related structures including trigeminal ganglion and brainstem; moreover, thymoquinone inhibited degranulation of MMCs and prevented the increase in the number of MMCs in GTN-induced in vivo migraine model. However, in the ex vivo meningeal preparations, thymoquinone did not inhibit the GTN-induced CGRP release from trigeminal meningeal afferents. Our findings suggest that thymoquinone mediates modulation of CGRP release in trigeminal ganglion neurons and brainstem, and stabilization of MMCs. Thus, thymoquinone may be a promising candidate to prevent the meningeal neurogenic inflammation and consequently migraine.