hypericum and Seizures

In this work, previously published and unpublished results on biological activity of Hypericum caprifoliatum, a native species to South Brazil, are presented. Lipophilic extracts obtained from this species showed an antidepressant-like activity in mice and rat forced swimming test. Results from in vivo experiments suggest an effect on the dopaminergic transmission. Besides that, in vitro experiments demonstrated that the extract and its main component (a phloroglucinol derivative) inhibit monoamine uptake in a concentration-dependent manner, more potently to dopamine, but this effect is not related to direct binding at the uptake sites. It was also observed that a 3-day treatment with lipophilic extract prevents stress-induced corticosterone rise in mice frontal cortex but not in plasma. The lipophilic and methanolic H. caprifoliatum extracts also demonstrated antinociceptive effect, which seems to be indirectly mediated by the opioid system. These results indicate that H. caprifoliatum presents a promising antidepressant-like effect in rodents which seems to be related to a mechanism different from that of other classes of antidepressants.

Topics: Animals; Antidepressive Agents; Anxiety; Brazil; Depression; Hypericum; Pain; Plant Extracts; Rodentia; Seizures

Hypericum (H.) spp. has been used in traditional medicine for their anticonvulsant effect for many years. In spite of many works on this genus, little is known about H. scabrum. In this work, anticonvulsant activity of H. scabrum was investigated.. Anticonvulsant activity of aqueous extract was evaluated by pentylenetetrazole (PTZ) induced convulsion and picrotoxin induced convulsion. Also, nitric oxide radical scavenging was investigated as a possible mechanism involved.. Extract (125-500 mg kg-1, i.p.) significantly delayed the onset of PTZ induced convulsion. At 500 mg kg-1, 100% protection against mortality was observed. At this dose, it significantly prolonged the onset of picrotoxin induced convulsion in mice, too. It showed significant nitric oxide radical scavenging activity.. Mechanism of anticonvulsant activity may be through GABA and/or nitric oxide pathway.

Topics: Animals; Anticonvulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Free Radical Scavengers; gamma-Aminobutyric Acid; Hypericum; Male; Medicine, Traditional; Mice; Nitric Oxide; Pentylenetetrazole; Picrotoxin; Plant Extracts; Seizures; Time Factors

The present study was undertaken to investigate the putative activity of a methanol extract of Hypericum montbretti (Guttiferae) on the central nervous system. Rutin (1519 ppm) and quercitrin (784 ppm) were identified as the major phenolic compounds in the extract. When administered at 25, 50 and 100 mg/kg doses, the extract decreased the total number of head-dipping behaviours performed by mice during a hole-board test. Administration of both the extract and diazepam (2 mg/kg) reduced spontaneous locomotory activity, potentiated hexobarbital (60 mg/kg)-induced sleeping parameters and prevented pentylenetetrazole (80 mg/kg)-induced seizures relative to the controls. These findings are the first to indicate the sedative and anticonvulsant activities of H. montbretti extract. Atropine (2 mg/kg) and naloxone (5 mg/kg) pre-treatment did not reverse the sedative effect, indicating that muscarinic and opioidergic mechanisms did not contribute to the pharmacological action. However, pre-treatment with flumazenil (a benzodiazepine receptor antagonist) reversed both the sedative and anticonvulsant effects induced by a 100 mg/kg dose of the extract, indicating the involvement of the GABA(A)-benzodiazepine receptor complex. In conclusion, H. montbretti extract is a novel candidate as a sedative and anticonvulsant drug for the treatment of sleep disorders and for the prevention of epileptic seizures.

Topics: Animals; Anticonvulsants; Behavior, Animal; Central Nervous System; Diazepam; Exploratory Behavior; Hexobarbital; Hypericum; Hypnotics and Sedatives; Male; Mice; Motor Activity; Pentylenetetrazole; Plant Extracts; Receptors, GABA-A; Seizures; Sleep

Therapeutic effect of Hypericum perforatum L. has been well known. The aim of this study is to investigate the anticonvulsant effects of Hypericum methanolic extract against seizure induced by picrotoxin in mice. The study were performed on four groups of animals. They received percolated extract of Hypericum perforatum at the doses of 25, 50, 100 & 200 mg/kg intra peritoneally. After 20 minutes animals received picrotoxin 10 mg/kg for induction of seizure. Latency of seizure, duration of seizure, death latency and percent of mortality were determined. The results indicated that latency of seizure increased in pretreated group with the dose of 50 mg/kg (p<0.01). The higher dose of extract 200 mg/kg significantly decrease duration of seizure and death latency. It maybe due to unknown ingredients in this plant or producing concentrations higher than the therapeutic level. The results showed that Hypericum perforatum L. at the dose of 50 mg/kg maybe have some beneficial effect in seizure induced by picrotoxin and this plant is suitable for continuing search in this field.

Topics: Animals; Hypericum; Male; Mice; Phytotherapy; Picrotoxin; Plant Extracts; Seizures

The purpose of this study was to investigate the effects of treatment with water, n-butanol and ether extracts of Hypercom perforatum L. on epileptogenesis in rabbits. Animals from the control group received solvent-ethanol, and the kindling model of epilepsy was used. Epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus. The following parameters were determined: the minimum current strength necessary to induce after-discharge (AD) - discharges appearing after cessation of stimulation; AD duration; the number of stimulations necessary to induce spontaneous kindling; and the latency time for the development of full kindling. The results obtained indicate that epileptogenesis is influenced by Hypericum perforatum L. extract treatment. Animals treated with an ether extract of Hypericum perforatum L. required significantly weaker minimum current strengths for the development of epileptogenic focus, and displayed longer AD times, while the number of electro-stimulations necessary for full kindling was less. In contrast, animals treated with water and n-butanol extracts required increased electro-stimulations for the development of epileptic discharge, and displayed shortened AD durations versus controls.

Topics: Animals; Anticonvulsants; Deep Brain Stimulation; Female; Hypericum; Kindling, Neurologic; Male; Plant Extracts; Rabbits; Seizures

Topics: Adolescent; Depression; Drug Overdose; Electroencephalography; Female; Humans; Hypericum; Phytotherapy; Plant Preparations; Seizures

Hypericum perforatum L. is used in traditional medicine for its anticonvulsant property. We studied the anticonvulsant activity of the aqueous and ethanolic extracts of Hypericum perforatum aerial parts in mice in order to evaluate the traditional use of this plant. The pentylenetetrazole (PTZ) and the maximal electroshock seizure (MES) tests were used for assessing the anticonvulsive effects of this plant. In the PTZ test, the extracts (0.1-1g/kg, i.p.) delayed the onset of tonic convulsions and protected mice against mortality. In the MES test, both extracts did not showed an antiseizure activity. L-NAME (1-10 mg/kg, i.p.), a nitric oxide (NO) synthase inhibitor, reduced the anticonvulsant activity of the extracts. The results of this study indicate that the extracts of Hypericum perforatum aerial parts could contribute to the control of petit mal seizure and this effect may be partially mediated by nitric oxide pathway.

Topics: Animals; Anticonvulsants; Cyclic GMP; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Electroshock; Ethanol; Hypericum; Injections, Intraperitoneal; Lethal Dose 50; Medicine, Traditional; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Pentylenetetrazole; Plant Components, Aerial; Plant Extracts; Receptors, N-Methyl-D-Aspartate; Seizures; Water