OBJECTIVE: To study the regulatory mechanism of MS275, a histone deacetylase inhibitor, on the p38 MAPK signaling pathway in rats with convulsion in the developmental stage. METHODS: Thirty-two male rats were randomly divided into four groups: control, pentylenetetrazol (PTZ), PTZ+3 mg/kg MS275, and PTZ+6 mg/kg MS275 (n=8 each). A rat model of convulsion in the developmental stage was prepared by an intraperitoneal injection of PTZ. The rats in the control group were given an injection of normal saline alone. MS275 was given by an intraperitoneal injection at 2 hours before PTZ injection. At 24 hours after successful modeling, 6 rats were taken from each group. Western blot and qRT-PCR were used to measure the protein and mRNA expression of p38, MK2, cAMP response element-binding protein (CREB), and interleukin-6 (IL-6) in the hippocampus. Hematoxylin-eosin (HE) staining was used to observe brain pathological changes. Western blot was used to measure the expression of CD11b as a marker for the activation of microglial cells. RESULTS: Compared with the control group, the PTZ group had significant increases in the mRNA and protein expression of p38, MK2, CREB, and IL-6 (P<0.05). MS275 significantly inhibited the mRNA and protein expression of the above markers in the rats with convulsion in the developmental stage (P<0.05), and 6 mg/kg MS275 had a significantly better inhibitory effect on the mRNA and protein expression of IL-6 and CREB than 3 mg/kg MS275 (P<0.05). HE staining showed that the PTZ group had marked neuron apoptosis, cellular edema, and inflammatory cell infiltration, while MS275 intervention alleviated neuron apoptosis and cellular edema and reduced inflammatory cell infiltration in the rats with convulsion. The PTZ group had a significant increase in the activation of microglial cells, while MS275 significantly inhibited the activation of microglial cells in the rats with convulsion (P<0.05); 6 mg/kg MS275 had a significantly better inhibitory effect than 3 mg/kg MS275 (P<0.05). CONCLUSIONS In rats with convulsion in the developmental stage, the histone deacetylase inhibitor MS275 can inhibit the p38 MAPK signaling pathway, the apoptosis of hippocampal neurons, and the activation of microglial cells and thus reduce inflammatory response and convulsion-induced brain injury in a dose-dependent manner.
Animals ; Male ; Pentylenetetrazole ; Rats ; Rats, Sprague-Dawley ; Seizures ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases

To investigate the effects of neuronal histamine on spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and to explore its mechanisms.A subconvulsive dose of pentylenetetrazole (35 mg/kg) was intraperitoneally injected in rats every 48 h to induce chemical kindling until fully kindled. Morris water maze was used to measure the spatial memory acquisition of the rats one week after fully pentylenetetrazole-kindled, and the histamine contents in different brain areas were measured spectrofluorometrically. Different dosages of hitidine (the precursor of histamine), pyrilamine (H1 receptor antagonist), and zolantidine (H2 receptor antagonist) were intraperitoneally injected, and their effects on spatial memory acquisition of the rats were observed.Compared with control group, escape latencies were significantly prolonged on Morris water maze training day 2 and day 3 in pentylenetetrazole-kindling epilepsy rats (all<0.05); and the histamine contents in hippocampus, thalamus and hypothalamus were decreased significantly (all<0.05). Escape latencies were markedly shortened on day 3 by intraperitoneally injected with histidine 500 mg/kg, and on day 2 and day 3 by intraperitoneally injected with histidine 1000 mg/kg in pentylenetetrazole-kindling epilepsy rats (all<0.05). The protection of histidine was reversed by zolantidine (10 and 20 mg/kg), but not by pyrilamine.Neuronal histamine can improve the spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and the activation of H2 receptors is possibly involved in the protective effects of histamine.
Animals ; Benzothiazoles ; pharmacology ; Brain Chemistry ; drug effects ; Epilepsy ; chemically induced ; complications ; Hippocampus ; chemistry ; Histamine H1 Antagonists ; pharmacology ; Histamine H2 Antagonists ; pharmacology ; Histidine ; pharmacology ; Hypothalamus ; chemistry ; Kindling, Neurologic ; physiology ; Memory Disorders ; drug therapy ; etiology ; Pentylenetetrazole ; Phenoxypropanolamines ; pharmacology ; Piperidines ; pharmacology ; Pyrilamine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Histamine H2 ; drug effects ; physiology ; Spatial Memory ; drug effects ; Spectrometry, Fluorescence ; Thalamus ; chemistry

Epilepsy is a brain disorder that affects millions of people worldwide. It is characterized by recurrent and unpredictable seizures that are usually controlled with antiepileptic/anticonvulsive drugs. However, most antiepileptic drugs produce various side effects such as tolerance and sedation. Thus, there is a growing interest for alternative anticonvulsive drugs, preferably from natural or herbal sources. In this study, we evaluated the anticonvulsive effects of Rehmannia glutinosa (RG). The anticonvulsive effect of RG extract was evaluated using electroshock- and chemical-induced seizure tests in mice. To identify its probable mechanism of action, the effects of RG extract on Cl− influx was measured in vitro. We found that RG extract has anticonvulsive effects against electroshock-induced seizures, as indicated by an increased seizure threshold in mice. The RG extract also decreased the percentage of seizure responses induced by the GABAergic antagonist, pentylenetetrazole. These results suggest that the anticonvulsive effects of RG extract are mediated through a GABAergic mechanism. In support of this mechanism, our in vitro test showed that RG extract increases intracellular Cl− influx. Furthermore, RG extract did not show sedative and/or muscle relaxant effects in the open-field and rota-rod tests. Altogether, these results confirm that RG extract could be a herbal anticonvulsant and a potential alternative for clinical use.
Animals ; Anticonvulsants ; Brain Diseases ; Epilepsy ; gamma-Aminobutyric Acid* ; In Vitro Techniques ; Mice ; Pentylenetetrazole ; Rehmannia* ; Seizures* ; Water*

Animals ; Anticonvulsants ; pharmacology ; Drug Evaluation, Preclinical ; methods ; GABA-A Receptor Antagonists ; pharmacology ; Motor Activity ; drug effects ; Pentylenetetrazole ; pharmacology ; Valproic Acid ; pharmacology ; Zebrafish

The present study is to explore the change process and distribution of phosphorylated DARPP-32 (p-DARPP-32) in rat brain including cortex, hippocampus and striatum and to further deduce whether p-DARPP-32 was possibly involved in epilepsy induced by repetitive low doses of pentylenetetrazol (PTZ). PTZ-induced epilepsy model in rat was established with 30 male SD rats randomly divided into 6 groups, control group and five trial groups [PTZ 1 h, PTZ 6 h, PTZ 24 h, PTZ 48 h and PTZ 72 h respectively, after onset of status epilepticus (SE)]. Immunohistochemistry and immunofluorescence double-labeling were used to detect the temporal time change and distribution of p-DARPP-32 expression and to analyze the coexpression of DARPP-32 and p-DARPP-32 in rat brain after the onset of PTZ-induced generalized SE. The results showed that there was a temporal time change of p-DARPP-32 expression in rat brain after the onset of SE. The number of p-DARPP-32-positive cells increased significantly and reached the peaks at the ends of 1 hour and 6 hours after the onset of SE, but decreased at the end of 24 hours. The moderate to strong p-DARPP-32-immunopositive neurons were observed in cortex, hippocampus and striatum, and located in cell cytoplasm and cell nucleus. Further immunofluorescence double-labeling revealed that denser colocalization of p-DARPP-32 and DARPP-32 in the neurons existed in the area mentioned above. Therefore, PTZ-induced SE may cause phosphorylation of DARPP-32 in rat brain. The temporal time change and distribution of p-DARPP-32 suggest that phosphorylation of DARPP-32 may be involved in PTZ-induced epilepsy in rat brain including cortex, hippocampus and striatum, and p-DARPP-32 may play a central role in the onset of SE.
Animals ; Cerebral Cortex ; metabolism ; Corpus Striatum ; metabolism ; Dopamine and cAMP-Regulated Phosphoprotein 32 ; metabolism ; Hippocampus ; metabolism ; Male ; Neurons ; metabolism ; Pentylenetetrazole ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; chemically induced ; metabolism

Various antiepileptic drugs (AEDs) especially enzyme-inducing AEDs might be associated with increased vascular risk, through impairment of the endogenous antioxidative ability which may trigger oxygen-dependent tissue injury. Lamotrigine (LTG) a non-enzyme-inducing AED has scarce information regarding its effects on oxidative stress. The present study aimed to study the possible modulation of vascular risk factors of epileptogenesis by LTG, in a rat model of kindling seizure induced by pentylenetetrazole (PTZ). Four groups of male Wister rats were used; vehicle control group, PTZ group (alternate day PTZ, 30 mg/kg, i.p), LTG/PTZ group (LTG 20 mg/kg/day p.o and alternate day PTZ) and LTG group. The study period was 5 weeks. Lipoproteins and total homocysteine (tHcy), malondialdehyde (MDA) and reduced glutathione (GSH) were measured. Aortic endothelial function study and histopathological examination of the rats' brains, aortas and coronaries were conducted. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), tHcy, MDA, GSH levels were significantly higher in epileptic rats than normal controls rats. A decrease in HDL-cholesterol with high atherosclerotic index was also demonstrated. The administration of LTG improved the PTZ-kindled seizures. It produced a significant decrease in TC, TG and LDL-cholesterol, MDA, aortic GSH and increase in HDL-cholesterol with no significant effect on serum GSH and tHcy levels. LTG improved endothelium-dependent relaxation, decreased hippocampal neurodegenerative changes and atherosclerotic changes of aortas and coronaries. LTG decreased seizures severity, hippocampal damage and improved vascular risk markers in this rat model of kindling seizures.
Animals ; Anticonvulsants ; Aorta ; Brain ; Cholesterol ; Epilepsy ; Glutathione ; Homocysteine ; Humans ; Lipoproteins ; Male ; Malondialdehyde ; Models, Animal* ; Oxidative Stress ; Pentylenetetrazole* ; Rats ; Relaxation ; Risk Factors ; Seizures* ; Triglycerides

OBJECTIVETo investigate and compare the effects of Compound Chaihu Shugan Decoction (CHSGD, "treatment from Gan") and Dingxian Pill (DXP, "treatment from the sputum") on the metabolism path of glutamate in the pentylenetetrazol-kindled seizure rats' hippocampus, thus exploring the molecular mechanism of "heterotherapy for homopathy".

METHODSA chronic kindling seizures rat model was established by intraperitoneal injecting pentylenetetrazol (PTZ). Totally 24 fully kindled seizure rats were randomized into four groups, i.e., the model control group, the Sodium Valproate (VPA) group, the DXP group, and the CHSGD group. They were respectively treated with normal saline, VPA, CHSGD, and DXP, respectively. Rats in the control group were treated with normal saline by peritoneal injection and by gastrogavage. After intragastric administration for 4 successive weeks, the glutamate (Glu) levels in the hippocampus were detected by high performance liquid chromatography (HPLC). The expressions of glutamate transporter-1 (GLT-1) proteins were detected by Western blot. The activity of glutamine synthetase (GS) was detected by using GS detection kit.

RESULTSCompared with the control group, the content of Glu in the model group significantly increased, and the expression of GLT-1 and the activity of GS significantly decreased (P < 0.01). Compared with the model group, the content of Glu in each medication group significantly decreased, and the protein expression of GLT-1 as well as the activity of GS significantly increased (P < 0.01). But when compared between the CHSGD group and the DXP group, the content of Glu was lower and the activity of GS was higher in the CHSGD group than in the DXP group (P < 0.01), while there was no statistical difference in the expression of GLT-1 between the two groups (P > 0.05).

CONCLUSIONSCHSGD ("treatment from Gan") and DXP ("treatment from the sputum") could both decrease the level of Glu and raise the expression of GLT-1 and the activity of GS, indicating that CHSGD and DXP both could regulate the metabolism path of Glu to affect the level of the Glu in the brain. But the effects of CHSGD were superior to those of DXP in decreasing the content of Glu and up-regulating the activity of GS, suggesting that there were some different effects targets between the two compounds on the metabolism path of Glu, which may be one of possible molecular mechanisms for treating epilepsy by heterotherapy for homopathy.

Animals ; Excitatory Amino Acid Transporter 2 ; metabolism ; Glutamic Acid ; metabolism ; Hippocampus ; metabolism ; Kindling, Neurologic ; Male ; Medicine, Chinese Traditional ; methods ; Pentylenetetrazole ; adverse effects ; Rats ; Rats, Wistar ; Seizures ; metabolism ; therapy

BACKGROUNDHistamine H(3) receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed to investigate the effects of thioperamide, a selective and potent histamine H(3) receptor antagonist, on the seizure development and memory impairment induced by pentylenetetrazole (PTZ)-kindling epilepsy in rats.

METHODSChemical kindling was elicited by repeated intraperitoneal (ip) injections of a subconvulsant dose of PTZ (35 mg/kg) once every 48 hours for 12 times, and seizure activity of kindling was recorded for 30 minutes. Control rats were ip injected with saline instead of PTZ. Morris water maze was used to evaluate the spatial memory. Phosphorylated cyclic adenosine monophosphate response element binding protein (p-CREB) was tested by Western blotting in hippocampus.

RESULTSIntracerebroventricular (icv) injections with thioperamide (10 µg, 20 µg) 30 minutes before every PTZ injections, significantly prolonged the onset of PTZ-kindling and inhibited the seizure stages. PTZ-kindling seizures led to the impairment of spatial memory in rats, and thioperamide ameliorated the impairment of spatial learning and memory. Compared to non-kindling rats, there was a significant decrease in p-CREB level in hippocampus of the PTZ-kindling rats, which was reversed by thioperamide.

CONCLUSIONSThioperamide plays a protective role in seizure development and cognitive impairment of PTZ-induced kindling in rats. The protection of thioperamide in cognitive impairment is possibly associated with the enhancement of CREB-dependent transcription.

Animals ; Anticonvulsants ; pharmacology ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Histamine H3 Antagonists ; pharmacology ; Kindling, Neurologic ; drug effects ; Male ; Memory Disorders ; prevention & control ; Neuroprotective Agents ; pharmacology ; Pentylenetetrazole ; Piperidines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Seizures ; prevention & control ; Synaptic Transmission

Animals ; Kindling, Neurologic ; drug effects ; Male ; Pentylenetetrazole ; toxicity ; Rats ; Rats, Wistar ; Skin ; innervation ; Sympathetic Nervous System ; physiology

OBJECTIVETo compare seizure induced by different epileptic drugs in ICR mice.

METHODSMale adult ICR mice were injected with pilocarpine (Pilo), kainic acid (KA) and pentylenetetrazole (PTZ) to induce status epilepticus (SE). After 2 h of SE, seizures were terminated by injection of diazepam. Mice were sacrificed and sectioned for assessment of neuronal cell death by Fluro-Jade B staining after 7 d and mossy fiber sprouting by Timm staining after 28 d, respectively. Spontaneous seizures were detected by video for 28 d.

RESULTSPilo and KA induced typical SE in ICR mice, which was identical to those observed in rats and C57/BL6 mice. Timm staining showed evident mossy fiber sprouting in both Pilo and KA treated mice. The incidences of spontaneous seizure were 57.1% and 35.7% in Pilo and KA treated mice, respectively. Mice treated with PTZ represented kindling model. No mossy fiber sprouting and spontaneous seizures were observed. No cell death was detected in all three groups.

CONCLUSIONSimilar seizure pattern is observed in ICR mice as in rats and C57/BL6 mice. Both Pilo and KA model are the ideal models for chronic temporal lobe epilepsy. ICR mice can be widely used as a cheaper substitute in epilepsy research.

Animals ; Disease Models, Animal ; Epilepsy ; chemically induced ; Kainic Acid ; toxicity ; Male ; Mice ; Mice, Inbred ICR ; Pentylenetetrazole ; toxicity ; Pilocarpine ; toxicity