Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice / Efectos anticonvulsivos de Paeonia daurica subsp. macrophylla extractos de raíz en modelos de convulsiones inducidas por pentilentetrazol en ratones

Introduction: In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice. Methods: HE and its fractions as well as AE, in concentrations of (100, 200 and 400 mg/kg), valproate (Val) (100 and 200 mg/kg), and saline (negative control) (10 mg/kg) were injected intraperitoneally (i.p.) 30 min before PTZ (80 mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5 mg/kg, i.p.) before AE (100, 200, and 400 mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey–Krammer multiple comparison tests. Results: All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures. Conclusions: It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.(AU)

Introducción: Epilepsia es el término usado para un grupo de trastornos caracterizado por las convulsiones espontáneas recurrentes. Un estudio enfocado en los productos naturales de los recursos tradicionales ofrece ventajas significativas que se están utilizando de manera más amplia en modelos animales de epilepsia y candidatos a mayor desarrollo clínico y sus fracciones (F-CHCl3, F-EtOAc, F-MeOH) de Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) raíz examinada utilizando un modelo inducido por pentilentetrazol (PTZ) en ratones. Métodos: La maceración dinámica utilizada para extraer HE de la planta y técnica de cromatografía en columna de sílice utilizada para obtener F-CHCl3, F-EtOAc, así como fracciones de F-MeOH. La extracción de raíces secas se utilizó con agua destilada y se provocó AE. Las muestras de plantas (100, 200 y 400 mg/kg), valproato (Val) (100 y 200 mg/kg) y suero (control negativo) se inyectaron por vía intraperitoneal (ip) 30 min antes de PTZ (80 mg/kg, ip). El tiempo transcurrido antes del comienzo de convulsiones mioclónicas (MC), duración de las MC, tiempo transcurrido antes del comienzo de convulsiones tónico-clónicas generalizadas (GTCS), la duración de GTCS, así como el porcentaje de GTCS y protección contra la mortalidad registrada. Los mecanismos anticonvulsivos de planta fueron evaluados mediante el uso de flumazenil (5 mg/kg, ip) antes de AE (100, 200 y 400 mg/kg, ip) inyección. Se utilizaba el software GraphPad Prism® comparando las diferencias entre varios grupos de tratamiento con un análisis unilateral de variación (ANOVA) seguido por las pruebas de comparación múltiple de Tukey's Krammer. Resultados: Todas las muestras de plantas, excepto F-EtOAc, retrasaron de manera considerable el inicio, y disminuyeron la duración de PTZ inducidos por MCS y GTCS, y redujo significativamente el GTCS, así como la tasa de mortalidad...(AU)

Effect of converting from propofol to remimazolam with flumazenil reversal on recovery from anesthesia in outpatients with mental disabilities: a randomized controlled trial.

BACKGROUND: General anesthesia is often necessary for dental treatment of outpatients with mental disabilities. Rapid recovery and effective management of postoperative nausea and vomiting (PONV) are critical for outpatients. This study aimed to investigate the effect of transitioning from propofol to remimazolam with flumazenil reversal administered toward the end of surgery during propofol-based total intravenous anesthesia (TIVA) on recovery. METHODS: Adults with mental disabilities scheduled to undergo dental treatment were randomly assigned to receive either propofol-based TIVA (Group P) or propofol-remimazolam-based TIVA with flumazenil reversal (Group PR). Propofol was replaced with remimazolam 1 h before the end of surgery in Group PR; moreover, 0.5 mg of flumazenil was administered after the neuromuscular blockade reversal agent. The primary outcome was the duration of stay in the post-anesthesia care unit (PACU). The secondary outcomes included time to eye-opening, time to extubation, occurrence of PONV, and quality of recovery. RESULTS: Fifty-four patients were included in this study. The duration of stay in the PACU in Group PR was significantly shorter than that in Group P (mean difference, 8.7 min; confidence interval [95% CI], 3.3-14.2; P = 0.002). Group PR exhibited a shorter time to eye opening (mean difference, 5.4 min; 95% CI, 3.3-8.1; P < 0.001) and time to extubation (mean difference, 5.5 min; 95% CI, 3.6-7.9; P < 0.001) than Group P. Neither group required the administration of rescue analgesics, and the incidence of PONV was not reported. CONCLUSIONS: Transitioning from propofol to remimazolam 1 h before the end of surgery followed by flumazenil reversal reduced the duration of stay in the PACU and the time to eye opening and extubation without affecting the incidence of PONV and quality of recovery. TRIAL REGISTRATION NUMBER: Clinical Research Information Service (KCT0007794), Clinical trial first registration date: 12/10/2022.

Search for Novel Therapies for Essential Tremor Based on Positive Modulation of α6-Containing GABAA Receptors.

Background: Prior work using GABAA receptor subunit knockouts and the harmaline model has indicated that low-dose alcohol, gaboxadol, and ganaxolone suppress tremor via α6ßδ GABAA receptors. This suggests that drugs specifically enhancing the action of α6ßδ or α6ßγ2 GABAA receptors, both predominantly expressed on cerebellar granule cells, would be effective against tremor. We thus examined three drugs described by in vitro studies as selective α6ßδ (ketamine) or α6ßγ2 (Compound 6, flumazenil) receptor modulators. Methods: In the first step of evaluation, the maximal dose was sought at which 6/6 mice pass straight wire testing, a sensitive test for psychomotor impairment. Only non-impairing doses were used to evaluate for anti-tremor efficacy in the harmaline model, which was assessed in wildtype and α6 subunit knockout littermates. Results: Ketamine, in maximally tolerated doses of 2.0 and 3.5 mg/kg had minimal effect on harmaline tremor in both genotypes. Compound 6, at well-tolerated doses of 1-10 mg/kg, effectively suppressed tremor in both genotypes. Flumazenil suppressed tremor in wildtype mice at doses (0.015-0.05 mg/kg) far lower than those causing straight wire impairment, and did not suppress tremor in α6 knockout mice. Discussion: Modulators of α6ßδ and α6ßγ2 GABAA receptors warrant attention for novel therapies as they are anticipated to be effective and well-tolerated. Ketamine likely failed to attain α6ßδ-active levels. Compound 6 is an attractive candidate, but further study is needed to clarify its mechanism of action. The flumazenil results provide proof of principle that targeting α6ßγ2 receptors represents a worthy strategy for developing essential tremor therapies. Highlights: We tested for harmaline tremor suppression drugs previously described as in vitro α6ßδ or α6ßγ2 GABAA receptor-selective modulators. Well-tolerated flumazenil doses suppressed tremor in α6-wildtype but not α6-knockout mice. Compound 6 and ketamine failed to display this profile, likely from off-target effects. Selective α6 modulators hold promise as tremor therapy.

Flumazenil Treatment for Diazepam-Associated Neurological Signs in a Cat With a Portosystemic Shunt.

A 7-month-old female spayed domestic short hair cat was presented for evaluation of inadequate clinical response to medical management for hepatic encephalopathy (HE). An abdominal computed tomography (CT) was to be performed but the cat developed 2 grand mal seizures shortly after presentation. Minimal handling and no drugs had been administered before the seizures. A single dose of diazepam (0.3 mg/kg, IV) was administered after each seizure. Another seizure occurred 24 hours after hospitalization and diazepam (0.5 mg/kg, IV) was once again administered. Seizures ceased but neurological signs worsened and included head pressing, loss of menace response, and a stuporous mentation. Due to unresponsiveness to treatment that included administration of intravenous fluids, levetiracetam, ampicillin/sulbactam, and retention enemas (water with lactulose), a dose of flumazenil (0.01 mg/kg) was administered IV and resulted in immediate but transient improvement of clinical signs. The stuporous state returned after 60 min post-treatment and an additional dose of IV flumazenil (0.01 mg/kg) was administered with the same outcome. Based on this positive clinical response, IV infusion of flumazenil was initiated at 0.01 mg/kg/h following a loading dose of 0.005 mg/kg. Due to minimal improvement in neurological signs, flumazenil IV infusion was increased gradually until reaching the effective dose of 0.1 mg/kg/h. Flumazenil IV infusion was continued for 24 hours with improvements in neurological signs, which did not return upon gradual decrease of the flumazenil dose. This is the first report describing the use of a flumazenil IV infusion to improve neurological signs in a cat with a PSS and HE treated with diazepam.

Remimazolam Compared to Propofol for Total Intravenous Anesthesia with Remifentanil on the Recovery of Psychomotor Function: A Randomized Controlled Trial.

INTRODUCTION: This study aimed to compare remimazolam to propofol in psychomotor recovery after total intravenous anesthesia (TIVA) using the Trieger dot test. METHODS: Sixty-six patients who were scheduled to undergo endoscopic sinus surgery with American Society of Anesthesiologists (ASA) physical status I or II were randomly allocated to the remimazolam (group R) or propofol group (group P). In group R, all patients received flumazenil postoperatively. After discontinuation of anesthetic agents, the time to eye opening, response to verbal commands, extubation, and discharge from the operation room were measured. Psychomotor recovery was assessed using the Trieger dot test before induction and at 0, 30, 60, 90, 120, 150, and 180 min after anesthesia. RESULTS: The time to eye opening, response to verbal commands, extubation, and discharge from the operation room were significantly longer in group P compared to group R (group P: 9.8 ± 3.2 min, 11.5 ± 3.4 min, 12.7 ± 3.4 min, 18.1 ± 4.2 min; group R: 6.5 ± 2 min, 7.3 ± 2.6 min, 8.4 ± 2.9 min, 13.2 ± 3.2 min; respectively, p < 0.05). In the Trieger dot test, the number of dots missed was significantly increased in group R compared to group P at 30, 60, 90, and 120 min after discharge from the operation room (group R: 20.5 ± 9.3, 16 ± 8.8, 14.9 ± 11.1, 14.3 ± 10.8; group P: 14.6 ± 7.8, 10 ± 7.1, 8.7 ± 7.3, 7.3 ± 5.7; respectively, p < 0.05). The maximum distance of dots missed was significantly increased in group R compared to group P at 30 min after discharge from the operation room (group R: 3.9 ± 2.8; group P: 2.7 ± 1.6; p < 0.05). CONCLUSION: Our results suggest that remimazolam with flumazenil leads to rapid recovery following anesthesia; however, it may cause delayed psychomotor decline. CLINICAL TRIAL REGISTRATION: This trial is registered with the University Hospital Medical Information Network (registration number UMIN000044900).

Coma, Severe Hypotension, and Pinpoint Pupils After Olanzapine Intoxication in the Intensive Care Unit with Symptom Reversal After Administration of Flumazenil.

BACKGROUND Olanzapine is an antipsychotic drug and is used in critical care to treat delirium. There is no known antidote to olanzapine intoxication. Overdosing olanzapine can cause, tremor, bradykinesia, hypotension somnolence, coma, and miosis. CASE REPORT We present the case of a previously healthy 69-year-old man who after routine mitral valve surgery developed pneumonia and severe sepsis requiring several weeks on a ventilator in the Intensive Care Unit. He developed delirium and paranoia and was prescribed olanzapine. After 4 doses, he became hypotensive and nonresponsive and developed pinpoint pupils. The symptoms were reversed minutes after administration of flumazenil. The clinical picture in this case corresponds well with an olanzapine intoxication. No other drugs, such as benzodiazepines or opioids, had been administered that could explain the reaction. Olanzapine intoxication is known to present with hypotension, coma, and miosis. The doses given were normal starting doses for olanzapine in the outpatient setting but much higher than recommended doses in the intensive care setting. CONCLUSIONS This case illustrates a risk for severe adverse effects, even within normal prescription range, when olanzapine is used in the intensive care setting. Finally, it is intriguing that the symptoms were reversed after administration of flumazenil, a selective competitive antagonist of the GABA receptor. Olanzapine mainly effects dopamine, serotonin, a1-adrenergic, histamine, and muscarinic receptors, but a low affinity to GABA and benzodiazepine sites can perhaps explain the observed effect.

Effects of Hyssopus Officinalis Hydroalcoholic Extract on Pentylenetetrazol-Induced Convulsive Seizures in Rat.

Hyssopus officinalis L. is one of the most important medicinal plants in traditional medicine used to treat seizures. In this study, we assessed the effects of H. officinalis hydroalcoholic extract against pentylenetetrazol (PTZ)-induced seizures in rat. The anti-seizure activity of the extract was assessed in three doses of 25, 50, and 100 mg/kg. Kindling was induced by intraperitoneal injection of PTZ (35 mg/kg) every 48 h, and H. officinalis extract was administered daily and behavioral tests performed. The possible involvement of GABA receptors in the extract activity was investigated using flumazenil. Tonic seizure threshold and mortality rate were measured following intraperitoneal injection of 60 mg/kg PTZ on the 14th day, following 14 days administration of H. officinalis hydroalcoholic extract. Blood and hippocampus samples were prepared to measure brain and serum antioxidant capacity, malondialdehyde (MDA), and nitric oxide (NO). Finally, the expression of GABA receptor gene in brain tissue was investigated. H. officinalis extract increased tonic seizure threshold and decreased mortality due to PTZ. Flumazenil, as a GABA receptor antagonist, reduced the tonic seizure threshold. Extract treatment significantly improved memory and learning, increased brain antioxidant capacity, decreased brain MDA and NO in kindled rats. It also increased GABA receptor gene expression in pre-treated groups compared to the negative control group. H. officinalis extract probably exerts potential antiepileptic effects through the GABAergic system. Also, H. officinalis extract has a supportive effect against hippocampal neuronal damage and improves memory and learning in kindled rats.

Evaluation of maximum dose intravenous midazolam used in dental intravenous sedation: a West of Scotland regional audit.

Background Intravenous (IV) midazolam sedation is commonly used in the delivery of dentistry for phobic patients. There is currently no guidance on a maximum dose for use specifically in dentistry. Dentists practise with the British National Formulary recommended maximum dose of 7.5 mg; however, anecdotally, this is often exceeded. We aim to evaluate prescribing and propose recommendations for a maximum dose for dentists.Method Data was collected from ten dentists across four Scottish health boards regarding their last 20 IV sedation patients, giving a total of 200. Data obtained from standard Dental Sedation Teachers Group IV logbooks included: dose of midazolam administered; justification for doses over 7.5 mg; flumazenil or supplemental oxygen usage; significant medical/social factors; and the Ramsay Sedation Score.Results Mean midazolam dose was 6.1 mg with a range of 14 mg. The recommended maximum dose of 7.5 mg was exceeded in 28% of cases. The mean sedation score was 2.7 and there were no reported adverse events or use of flumazenil.Conclusion IV midazolam is an effective way to achieve conscious sedation in dentistry. Acknowledgement of current off-label prescribing is important; however, 7.5 mg as a recommended maximum dose is too conservative as it is regularly exceeded without adverse events. Further investigation and expert opinion is required to set a maximum dose specifically for dentistry.

Outcomes of patients treated with low-dose flumazenil for benzodiazepine detoxification: A description of 26 participants.

INTRODUCTION: Benzodiazepines are commonly prescribed for a variety of indications and can be employed in the short- and long-term. While they are efficacious, issues arise from long-term use with the emergence of dependence and tolerance to doses within the therapeutic range and beyond. Discontinuation from benzodiazepines can be problematic for patients and may result in a withdrawal syndrome, which can be protracted and last months to years. METHODS: 26 participants received low-dose subcutaneous flumazenil infusions (4 mg/24 h for approximately eight days) as part of a randomised control crossover trial. Return to benzodiazepine use was assessed monthly for three months based on the benzodiazepine use in the previous week. Where data was not available, the treating psychiatrist examined patient files and clinical documents to determine benzodiazepine use. Withdrawal and craving scores were also measured. RESULTS: Abstinence rates from benzodiazepines at one-, two-, and three-month follow ups were 65.4 %, 50.0 %, and 46.2 % respectively. When considering patient files and clinical documents for those lost to follow-up, abstinence rates were higher at 73.1 %, 65.4 % and 61.5 % at the one-, two-, and three-month follow ups respectively. Withdrawal and craving scores were higher in those that had returned to any benzodiazepine use. CONCLUSION: Self-reported rates of abstinence from benzodiazepines at three months was between 46.2 % and 61.5 %. Flumazenil may yield greater success than benzodiazepine tapering from high dose benzodiazepine use (≥30 mg diazepam equivalent). Further research should compare abstinence rates after treatment with flumazenil compared to benzodiazepine tapering in high dose benzodiazepine users.

A double-blind randomised crossover trial of low-dose flumazenil for benzodiazepine withdrawal: A proof of concept.

INTRODUCTION: Benzodiazepines (BZD) are a class of anxiolytics with varying uses, which primarily act on the GABAA receptor resulting in hyperpolarisation. BZDs are often a difficult drug class to cease once neuroadaptation has occurred; recommendations usually involve gradual dose reductions at variable rates. A growing body of evidence has suggested that low-dose flumazenil, a GABAA receptor antagonist, may be a useful agent to allow for rapid detoxification. AIM: To collect pilot data on the safety and efficacy of low-dose subcutaneous flumazenil to reduce BZD use, withdrawal symptoms, and craving in participants taking above and below the therapeutic maximum diazepam equivalent of 30 mg to inform on sample size for future trials. METHOD: In a randomised double-blinded crossover study design, participants received low-dose flumazenil first (4 mg/24 h for approximately eight days) or placebo first. Groups were divided into those taking < 30 mg diazepam equivalent and ≥ 30 mg diazepam equivalent at baseline. Main outcome measures were percentage reduction in daily diazepam use, withdrawal symptoms, and craving scores from baseline, difference in diazepam use across the placebo first group, and flumazenil related adverse events. RESULTS: Twenty-eight participants were recruited and randomised to flumazenil first (n = 14) and placebo first (n = 14). In participants taking ≥ 30 mg diazepam equivalent at baseline (n = 15), flumazenil significantly reduced diazepam use by 30.5% (p = 0.024) compared to placebo. CONCLUSION: Low-dose flumazenil may aid in BZD detoxification in participants taking daily diazepam equivalent doses greater than or equal to the therapeutic maximum (≥30 mg) by reducing the need for diazepam.

Midazolam-Induced Hiccups Reversed by Flumazenil: A Case Report.

Hiccups are a common phenomenon experienced by many people and are usually short-lived with spontaneous resolution of symptoms. Certain anesthetic medications have been associated with the development of hiccups, though the underlying pathophysiology and reflex arcs remain poorly understood. We describe a patient who developed hiccups lasting 9 days following an orthopedic surgery and again developed hiccups during a subsequent surgery after only having received midazolam; flumazenil administration led to sustained cessation of his hiccup symptoms immediately.

The Anticonvulsant Effect of Hydroethanolic Leaf Extract of Calotropis procera (Ait) R. Br. (Apocynaceae).

A number of currently used drugs have been obtained from medicinal plants which are a major source of drugs. These drugs are either used in their pure form or modified to a semisynthetic drug. Drug discovery through natural product research has been fruitful over the years. Traditionally, Calotropis procera is used extensively in the management of epilepsy. This study is conducted to explore the anticonvulsant effect of a hydroethanolic leaf extract of Calotropis procera (CPE) in murine models. This effect was evaluated using picrotoxin-induced convulsions, strychnine-induced convulsions, and isoniazid- and pilocarpine-induced status epilepticus in mice of both sexes. The results showed that CPE (100-300 mg/kg) exhibited an anticonvulsant effect against strychnine-induced clonic seizures by significantly reducing the duration (p = 0.0068) and frequency (p = 0.0016) of convulsions. The extract (100-300 mg/kg) caused a profound dose-dependent delay in the onset of clonic convulsions induced by picrotoxin (p < 0.0001) and tonic convulsions (p < 0.0001) in mice. The duration of convulsions was reduced significantly also for both clonic and tonic (p < 0.0001) seizures as well. CPE (100-300 mg/kg), showed a profound anticonvulsant effect and reduced mortality in the pilocarpine-induced convulsions. ED50 (~0.1007) determined demonstrated that the extract was less potent than diazepam in reducing the duration and onset of convulsions but had comparable efficacies. Flumazenil-a GABAA receptor antagonist-did not reverse the onset or duration of convulsions produced by the extract in the picrotoxin-induced seizure model. In isoniazid-induced seizure, CPE (300 mg kg1, p.o.) significantly (p < 0.001) delayed the onset of seizure in mice and prolonged latency to death in animals. Overall, the hydroethanolic leaf extract of Calotropis procera possesses anticonvulsant properties.

Bumetanide prevents diazepam-modified anxiety-like behavior in lipopolysaccharide-treated mice.

Benzodiazepine receptor agonists are widely prescribed therapeutic agents that alter gamma-aminobutyric acid (GABA)A receptor activity and have anxiolytic effects. Post-operative use of benzodiazepines is a risk factor of delirium. Inflammatory conditions alter the anxiolytic effects of benzodiazepine. We investigated the effect of diazepam, a typical benzodiazepine anxiolytic, on changes in the emotional behavior of mice in a hole-board test after lipopolysaccharide (LPS) treatment. Diazepam dose-dependently increased the number of head-dips at doses that did not alter locomotor activity; however, diazepam dose-dependently significantly decreased the number of head-dips at doses that did not alter locomotor activity in LPS-treated mice. Flumazenil, a benzodiazepine receptor antagonist, normalized the decrease in head-dipping behavior caused by diazepam treatment in normal and LPS-treated mice. The decrease of the head-dipping effect caused by diazepam was attenuated by minocycline in LPS-treated mice. We further found that the decrease in head-dipping behavior caused by diazepam was blocked by bumetanide, a Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) antagonist, in LPS-treated mice. These findings suggest that diazepam induces the anxiety-like behavior under inflammation conditions, and may cause the GABAA receptor dysfunction associated with the chloride plasticity mediated by NKCC1, which contributes to benzodiazepine-induced delirium after surgery.

Flumazenil therapy for a gabapentin-induced coma: a case report.

BACKGROUND: Spasticity and neuropathic pain are common in patients after spinal cord injury and negatively affect patients' quality of life. Gabapentin and baclofen are frequently used to treat these conditions. We present a flumazenil-reversed gabapentin-induced coma case, which, to our knowledge, is the second one described in scientific literature. CASE PRESENTATION: A 70-year-old Caucasian man was admitted to our neurorehabilitation ward following a fall with cervical trauma that resulted in immediate tetraplegia. During his stay, he suffered from lower limb pain, both neuropathic and due to severe spasticity. Gradual baclofen and gabapentin administration was prescribed, with reduction in both pain and spasticity. One morning, the patient was found unresponsive, with a Glasgow Coma Score of 3. Head computerized tomography, electrocardiogram, electroencephalogram, vital signs, blood tests, breathing, and blood oxygenation were normal. Renal and liver failure were ruled out. Intravenous 0.25 mg of flumazenil (Anexate) was administered, resulting in complete neurocognitive recovery with a Glasgow Coma Score of 15. DISCUSSION AND CONCLUSIONS: This case report highlights the importance of the individual response to certain pharmacological agents and suggests that further studies need to be conducted both on flumazenil and gabapentin pharmacodynamics to better understand their molecular-receptor activity, and on possible multiple flumazenil mechanisms of action, beyond its classical strict benzodiazepine antagonist action.

Cymbopogon citratus (DC.) Stapf, citral and geraniol exhibit anticonvulsant and neuroprotective effects in pentylenetetrazole-induced seizures in zebrafish.

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon citratus (DC.) Stapf (C. citratus) is consumed as an infusion in folk medicine due to its pharmacological properties and action in the central nervous system. Epilepsy is a neurological disorder that affects millions of people. Since the currently available antiepileptic drugs often cause undesirable side effects, new alternative therapeutic strategies based on medicinal plants have been proposed. AIM OF THE STUDY: This study aimed to investigate the anticonvulsant and neuroprotective effects of C. citratus essential oil (EO) and hydroalcoholic extract (E1) from its leaves, as well as of its related compounds citral (CIT) and geraniol (GER) against the effects of pentylenetetrazole (PTZ) induced seizures in zebrafish (Danio rerio). MATERIALS AND METHODS: To evaluate the anticonvulsant properties of the samples, adult animals were pre-treated (by immersion) and subsequently exposed to PTZ solution. The involvement of GABAA receptors in the antiepileptic effects was investigated by the coadministration of flumazenil (FMZ), a known GABAA receptor antagonist. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and nitric oxide (NO) were assessed in zebrafish brain homogenates after PTZ exposure. RESULTS: All samples increased the latency time for the first seizure, which was reduced when animals were pretreated with FMZ, suggesting the involvement of GABAA receptors in the observed properties. The association between CIT and GER at the lowest concentration studied showed a synergistic effect on the anticonvulsant activity. Decreases in MDA and NO levels and increases in GSH and CAT levels in the brain of treated animals suggested the neuroprotective effect of the compounds investigated. CONCLUSIONS: Our results proved that C. citratus EO, E1, CIT and GER have anticonvulsant effects in zebrafish and could be used as a promising adjuvant therapeutic strategy for epilepsy treatment. Furthermore, zebrafish demonstrated to be an alternative animal model of epilepsy to evaluate the anticonvulsant and neuroprotective effects of C. citratus.

[123I]Iomazenil SPECT Detects a Reversible Lesion of the Left Medial Temporal Lobe in a Case of Global Autobiographical Amnesia.

Global autobiographical amnesia is a rare disorder that is characterized by a sudden loss of autobiographical memories covering many years of an individual's life. Generally, routine neuroimaging studies such as CT and MRI yield negative findings in individuals with global autobiographical amnesia. However, in recent case reports, functional analyses such as SPECT and fMRI have revealed changes in activity in various areas of the brain when compared with controls. Studies using iomazenil (IMZ) SPECT with individuals with global autobiographical amnesia have not been reported. We report the case of a 62-year-old Japanese woman with global autobiographical amnesia who had disappeared for ∼4 weeks. [123I]-IMZ SPECT showed reduced IMZ uptake in her left medial temporal lobe and no significant reduction on N-isopropyl-[123I] p-iodoamphetamine (IMP) SPECT in the identical region. Because IMZ binds to the central benzodiazepine receptor, this dissociation between IMZ and IMP SPECT was thought to reflect the breakdown of inhibitory neurotransmission in the left medial temporal lobe. Moreover, when the woman recovered most of her memory 32 months after fugue onset, the IMZ SPECT-positive lesion had decreased in size. Because the woman had long suffered verbal abuse from her former husband's sister and brother, which can also cause global autobiographical amnesia, it is difficult to conclude whether the IMZ SPECT-positive lesion in the left medial temporal lobe was the cause or the result of her global autobiographical amnesia. Although only one case, these observations suggest that IMZ SPECT may be useful in uncovering the mechanisms underlying global autobiographical amnesia.

High-dose benzodiazepine dependence among health-care professionals: A neglected phenomenon.

Chronic use of benzodiazepines (BDZs) is a widespread phenomenon which can lead to side effects such as tolerance, dependence and cognitive impairment, as well as resulting in accidents at work. High-dose BDZ dependence (HD-BDZ) is little studied, and it is mainly attributed to major psychiatric disorders and polydrug abuse. To date, few studies have investigated HD-BDZ among active workers, with none among health-care professionals (HPs). Tapering from high doses of BDZs can cause severe withdrawal symptoms, including seizures. The Addiction Unit of the University Hospital in Verona uses a protocol based on flumazenil slow infusion (FLU-SI), the safest and most effective treatment for HD-BDZ. Since 2003, 1281 patients have been detoxified from long-term use of high doses of BDZ using FLU-SI. The sample includes 139 (10.8%) HPs. Mean daily doses were 336 mg diazepam equivalent among HPs and 365 mg diazepam equivalent among non-HPs (no statistically significant difference). HPs are at higher risk of sleep disorders and work-related stress. Most of these HPs experience difficulties at work due to cognitive impairment, but they are often afraid of the potential legal implications and too ashamed to ask for help. It is important to study the prevalence of HD-BDZ among HPs and to investigate the impact on their working skills and working eligibility.