Background: In this study, the aqueous extract of Anethum graveolens (dill) leaves was studied for its effects on treating convulsions and epilepsy, by using a pentylenetetrazole (PTZ) kindling model. The evaluated plant has a traditional medical reputation for profound anticonvulsant activities, additionally, dill has been claimed to exhibit anti-inflammatory and analgesic properties. Methods: For the PTZ kindling induction, mice were given a dose of PTZ (37 mg/kg, intraperitoneally) every other day, and seizure stages were precisely recorded. During and after kindling, the effects of the non-toxic doses of the aqueous extracts (100, 250, and 400 mg/kg) on seizure latency in stage 2 (S2L), seizure latency in stage 4 (S4L), and seizure duration in stage 5 (S5D) were measured. Results: The aqueous extract of dill leaves had a noticeable anticonvulsant effect. The 400 mg/kg dose of the extract sample decreased with S5D (P < 0.05), and increased with S2L and S4L significantly (P < 0.05 and P < 0.01, respectively). Conclusion: The obtained data shows that the aqueous extract possesses anticonvulsant activity against seizure induced by PTZ. The presence of anticonvulsant compounds in this medicinal herb suggests further activity and guided fractionation studies in order to introduce this plant as a valuable source of anticonvulsant agents.
Anethum graveolens ; Anticonvulsants ; Pentylenetetrazole

PURPOSE: The expression of c-Fos protein has been shown to be a useful marker for elevated levels of neuronal activity generated in the brain following different stimuli, including seizures. This study was conducted to investigate distribution and numbers of neurons where dentate and cingulate gyrus become activated following pentylenetetrazol-induced seizures by means of expression patterns of c-Fos protein. METHODS: Rats were sacrificed at increasing times(1 hour, 2 hours, 8 hours, 1 day, 4 days and 7 days) after pentylenetetrazol-induced seizure. Rat brains were removed and sliced in rat brain matrix. Brain slices were coronal sectioned at interaural 5.70-6.70mm. Serial sections were immunohistochemically reacted with polyclonal c-Fos antibody. The distribution and numbers of c-Fos protein immunoreactive neurons in dentate gyrus and cingulate gyrus were examined and analyzed statistically with Mann-Whitney U test. RESULTS: The numbers of c-Fos protein immunoreactive neurons in dentate gyrus peaked at 1 hours and reached almost normal conditions at 7 days after seizure. Also, same patterns were occurred in cingulate gyrus. Concentration value that pentylenetetrazol can induce was different from each animals and c-Fos immunoreactive cells were various kinds of neurons. CONCLUSION: Higher numbers of c-Fos protein immunoreactive neurons were found in dentate and cingulate gyrus at the same times after seizure. These findings suggest that neurons of dentate and cingulate gyrus play a crucial role in seizure onset following pentylenetetrazol-induced seizure.
Animals ; Brain* ; Dentate Gyrus ; Gyrus Cinguli ; Neurons ; Pentylenetetrazole ; Rats* ; Seizures*

In the present study, the effects of tamoxifen on pentylenetetrazole (PTZ)-induced repeated seizures and hippocampal neuronal damage in ovariectomized rats were investigated. Thirty seven virgin female Wistar rats were divided to: (1) control, (2) sham-PTZ, (3) sham-PTZ-tamoxifen (sham-PTZ-T), (4) Ovariectomized -PTZ (OVX-PTZ) and (5) OVX-PTZ-tamoxifen (OVX-PTZ-T) groups. The animals of groups 3 and 5 were injected by tamoxifen (10 mg/kg) on 7 consecutive days. After 7 days of tamoxifen injection, they also were then injected by tamoxifen 30 min prior each PTZ injection. PTZ (40 mg/kg) was injected on 6 consecutive days and the animal behaviors were observed for 60 min. The histological methods were then used to determine dark neurons in hippocampus. A significant decrease in the seizure score was seen in OVX-PTZ group compared to Sham-PTZ. The animals of OVX-PTZ-T group had a significant higher seizure score compared to OVX-PTZ group. The dark neurons in DG of OVX group were lower than sham group (p<0.01). The numbers of dark neurons in CA1 area of OVX-PTZ-T group was higher than OVX-PTZ group (p<0.05) compared to control, the numbers of dark neurons in CA3 area showed a significant increase in Sham-PTZ and OVX-PTZ group (p<0.05 and p<0.01 respectively). Dark neurons in OVX-PTZ-T group were higher than OVX-PTZ group (p<0.05). It is concluded that pretreatment of the ovariectomized rats by tamoxifen increased PTZ-induced seizure score and dark neurons. It might be suggested that tamoxifen has agonistic effects for estrogen receptors to change the seizure severity.
Animals ; Behavior, Animal ; Female ; Hippocampus ; Humans ; Neurons ; Pentylenetetrazole ; Rats ; Rats, Wistar ; Receptors, Estrogen ; Salicylamides ; Seizures ; Tamoxifen

BACKGROUND: Tissue injury by surgical manipulation or trauma may cause pain hypersensitivity secondary to central sensitization. The aim of this study was to evaluate the postoperative effect of gabapentin on incisional pain in rat pretreated with pentylenetetrazole. METHODS: Thirty rats were divided into 5 groups, a control group (n = 10), PTZ 10 group (n = 5), PTZ 20 group (n = 5), PTZ 30 group (n = 5), and a PG 30 group (n = 5). To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal thresholds were measured by calibrated von Frey filaments at 2 hr, 1 day, 2 days, 3 days, 4 days, and 5 days after the incision. RESULTS: The PTZ 10, 20, and 30 groups showed no significant difference in withdrawal thresholds when compared with the control group during 5 days postoperatively. There were no significant differences in withdrawal thresholds among the PTZ 10, 20, and 30 groups. However, the PG 30 group showed a significantly lower withdrawal threshold compared with the control group at postoperative days 3, 4 (p < 0.05), and 5 (p < 0.01). CONCLUSIONS: Intraperitoneal pentylenetetrazole administered before an incision had no effect on postoperative pain in the incisional pain model. However, gabapentin injection after an incision in rats pretreated with pentylenetetrazole caused hyperalgesia during 5 days postoperatively.
Animals ; Central Nervous System Sensitization ; Foot ; Hyperalgesia ; Hypersensitivity ; Pain, Postoperative ; Pentylenetetrazole* ; Rats*

The development of pentylenetetrazol (PTZ) kindling has been controversial, authors confirmed the development of kindling phenomenon in experimental rats following every second or third day intraperitoneal administration of PTZ(20-25mg/kg) to experimental rats and same amount of saline to control rats. The developmental stage of motor seizure could be categorized into five stages (stage I; clonic seizure of face and neck, stage II; clonic seizure of face, neck and forelimbs, stage III; clonic seizure of forelimbs and body with brief rearing, stage IV; falling and generalized clonic seizure, stage V; falling and generalized tonic-clonic seizure with tonic extension of hindlimbs). Linear regression analysis showed that the stages of motor seizure were increased with the number of PTZ injections (Y=0.1361X + 0.1943, p < 0.05). The persistence of kindling state was also observed after a 5-months pause of PTZ injection. This study suggested that PTZ kindling model in rats could be a good animal model of generalized epilepsy.
Animals ; Epilepsy, Generalized ; Forelimb ; Linear Models ; Models, Animal ; Neck ; Pentylenetetrazole* ; Rats* ; Seizures

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*

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

The present study was performed in order to test the effects of diphenylhydantoin (DPH) and two central nervous system (CNS) stimulants, intermittent light stimulation(ILS) and pentylenetetrazol (Metrazol) on body temperature (Tb) during cold exposure in the bat DHP delayed the onset of entry into hibernation in both the oriental discoloured bats and the little brown bats and formed long and prominent plateaus that were not found in the normal and the controls. The responses of body temperature to the ILS were sensitive and the body temperature fell dramatically in the big brown bats. Metrazol effects on body temperature were obvious but; seemed dose-dependent. The experimental results further support the hypothesis that hibernation is an epileptic fit as suggested by serveral researchers.
Animal ; Body Temperature/drug effects ; Body Temperature Regulation ; Chiroptera/physiology* ; Female ; Hibernation* ; Light ; Male ; Pentylenetetrazole/pharmacology ; Phenytoin/pharmacology

PURPOSE: In order to determine the effect of neuronal nitric oxide synthase(nNOS) in seizure-related neuronal vulnerability of the hippocampus, the expression patterns of nNOS were examined in pentylenetetrazole(PTZ)-induced seizure groups and in PTZ seizure groups which were pretreated with nNOS inhibitors. METHODS: Male Sprague-Dawley rats weighing 200-300 g were used in PTZ(40 mg/kg)-induced seizure experiments. A specific inhibitor, 50 mg/kg 7-nitroindazole(7-NI), and a non-specific inhibitor, 50 mg/kg nitro-L-arginine(L-NA) were treated 30 min before the administration of PTZ to block nNOS. nNOS expression was evaluated by using immunohistochemical staining in the hippocampus of each group. RESULTS: The onset time of the first myoclonic jerk was markedly delayed in the 7-NI and the L- NA pretreated groups in comparison to the PTZ group. In addition, 7-NI markedly suppressed the severity of PTZ-induced seizures. The expression of nNOS in the hippocampal CA3 area was higher than that in CA1 area in the PTZ treated groups. In the L-NA pretreated groups, the expression levels in the CA3 and CA1 areas were lower than those of the PTZ treated groups. Interestingly, in the 7-NI pretreated groups, the nNOS expression levels in CA1 and CA3 areas were makedly lower than those of PTZ and L-NA pretreated groups. There was no expression in CA2 area of all groups. CONCLUSION: These results suggest that the hippocampal neurons expressing nNOS may be vulnerable to PTZ-induced seizures and that nNOS may play an important role in seizure-related neuronal vulnerability.
Animals ; Hippocampus* ; Humans ; Immunohistochemistry ; Male ; Myoclonus ; Neurons* ; Nitric Oxide ; Nitric Oxide Synthase Type I* ; Pentylenetetrazole ; Rats* ; Rats, Sprague-Dawley ; Seizures*

PURPOSE: Nonsteroidal anti-inflammatory drugs inhibit the synthesis of prostaglandin(PG) through inhibition of the enzyme, cyclooxygenase. Some of the arachidonic acid metabolites may influence the spread of electrocortical activity, and delay the pentylenetetrazol(PTZ)-induced seizures. The purpose of the present study was to evaluate systematically the effect of pretreatment with PG synthetase inhibitors on PTZ-induced seizures. METHODS: To evaluate the effects of pretreatment with PG synthetase inhibitors on seizures produced by 30mg/kg, 60mg/kg PTZ, free-moving Sprague-Dawley rats weighing 250-300gm with chronically-implanted supracortical electrodes were used. Electrocorticogram was recorded for 1hr prior to pretreatment administration of either saline (control) or PG synthetase inhibitor and 1hr after administration of PTZ. RESULTS: 1) A 30mg/kg dose of PTZ produced bursts of high voltage activity after a latency of 616+/-72sec. Although the animals showed spontaneous movements throughout the test period, they were motionless or myoclonus. The number of high voltage bursts during the first hr of the test period was 368+/-31.2) A 30mg/kg of PTZ produced high voltage bursts after a latency of 1118+/-35sec which was significantly greater for the ibuprofen-pretreated groups receiving 90mg/kg when compared to the saline-pretreated group. In addition, the number of high voltage bursts(173+/-17) which occurred during the first hr of the test period was significantly smaller than that recorded from the saline-pretreated group. 3) After pretreatment with a 450mg/kg dose of paracetamol, a 30mg/kg of PTZ produced bursts of electrocortical activity with onset latencies of 665+/-112sec which were not significantly different than those recorded from the saline-pretreated group. The number of high voltage bursts during the first hr of the test period was 141+/-30 which was significantly smaller than that recorded from the saline-pretreated group. 4) A 50mg/kg dose of mefenamic acid pretreatment caused 30mg/kg PTZ-induced high voltage bursts after latency of 227+/-47sec which was significantly shorter than that recorded from the saline-pretreated group. The number of high voltage bursts during the first hr of the test period was 522+/-42 which was significantly greater than that recorded from the saline-pretreated group.5) A 60mg/kg dose of PTZ produced bursts of high voltage activity after a latency of 79+/-14sec. An electrocortical seizure with concurrent convulsions appeared subsequently by 129+/-30sec. 6) A 60mg/kg of PTZ produced high voltage bursts after a latency of 217+/-38sec which was significantly greater for the ibuprofen-pretreated groups receiving 90mg/kg when compared to the saline-pretreated group. An electrocortical seizure with concurrent convulsions appeared subsequently by 287+/-30sec.7) After pretreatment with paracetamol(450mg/kg), a 60mg/kg of PTZ produced bursts of electrocortical activity with onset latencies of 143+/-36sec which were significantly different than those recorded from the saline-pretreated group. There was no convulsive or no electrocortical seizure.8) A 50mg/kg mefenamic acid pretreatment caused 60mg/kg PTZ-induced high voltage bursts after latency of 35+/-5sec which was significantly shorter than that recorded from the saline-pretreated group. An electrocortical seizure appeared subsequently by 58+/-10sec which was significantly different than that recorded from the saline-pretreated group. CONCLUSION: It is possible that the delay and/or block of convulsions induced by the higher doses of PTZ was the result of PG synthesis inhibition. However, the PG synthetase inhibitors had a more differential effect on general PTZ-induced excitation of the CNS evidenced by changes in electrocortical activity. The mechanism underlying this action could be either through inhibition of the activity of cyclooxygenase in tissues which play a role in the manifestation of seizure activity or through an action not related to their common action on cyclooxygenase.
Acetaminophen ; Animals ; Arachidonic Acid ; Electrodes ; Ibuprofen ; Ligases ; Mefenamic Acid ; Myoclonus ; Pentylenetetrazole ; Prostaglandin-Endoperoxide Synthases* ; Rats, Sprague-Dawley ; Seizures*