Revealing the most effective anticonvulsant part of Malvaviscus arboreus Dill. Ex Cav. and its acute and sub-acute toxicity.

ETHNOPHARMACOLOGY RELEVANCE: Different parts of Malvaviscus arboreus Dill. Ex Cav. (M. arboreus) are traditionally used in the West Region of Cameroon to treat many diseases, including epilepsy. AIM OF THE STUDY: To determine which part of M. arboreus offers the best anticonvulsant effect, and to assess the acute and sub-acute toxicity of the part of interest. MATERIALS AND METHODS: the anticonvulsant effect of the aqueous lyophilisate of the decoction of flowers, leaves, stems and roots of M. arboreus at various doses was evaluated and compared on the model of acute epileptic seizures induced by pentylenetetrazole (PTZ) (70 mg/kg), injected 1 h after oral administration of the various extracts. Out of these plant parts, the leaves were then selected to prepare the hydroethanolic extract and its anticonvulsant effect against PTZ at the doses of 122.5, 245 and 490 mg/kg, as well as its acute toxicity were compared with those of the aqueous lyophilisate of the leaves. The anticonvulsant effect of the aqueous lyophilisate of M. arboreus leaves was further evaluated on models of acute epileptic seizures induced by picrotoxin (PIC) (7.5 mg/kg), strychnine (STR) (2.5 mg/kg) and pilocarpine (350 mg/kg). The 28 days sub-acute toxicity, as well as the quantitative phytochemistry and the in vitro antioxidant potential (FRAP, DPPH, ABTS+) of the aqueous lyophilisate of the leaves of M. arboreus were also evaluated. RESULTS: M. arboreus leaves showed the best anticonvulsant effect and the aqueous lyophilisate was the best extract. The latter significantly protected the animals against convulsions induced by PTZ (71.43%) (p < 0.01), PIC (57.14%) (p < 0.05) and STR (42%) and had no effect on pilocarpine-induced seizures. Furthermore, it showed no acute or sub-acute toxicity, and revealed a high content of flavonoids, saponins, tannins and alkaloids, and antioxidant activity in vitro. CONCLUSION: The aqueous lyophilisate of the leaves of M. arboreus offers the best anticonvulsant effect on the extraction solvent used, and it would act mainly via a potentiation of the inhibitory systems of the brain (GABA, Glycine). In addition, its richness in bioactive compounds gives it an antioxidant potential, and it is not toxic in acute and sub-acute toxicity. All this justifies at least in part its empirical uses, and makes M. arboreus a candidate for the alternative treatment of epilepsy.

Pharmacological and toxicological effects of Ruta chalepensis L. on experimentally induced seizures and electroencephalographic spectral power in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ruta chalepensis L. (Rutaceae) is used in traditional medicine to treat a wide variety of disorders such as rheumatism, fever, mental disorders, dropsy, neuralgia, menstrual problems, anxiety, and epilepsy. AIM OF THE STUDY: To evaluate and compare the anticonvulsant properties of an aqueous extract and ethyl acetate (AcOEt) fraction of R. chalepensis on pentylenetetrazole (PTZ)-induced seizures and maximal electroshock (MES) test in mice, by analyzing behavior and electroencephalogram (EEG), as well as GABAA receptors involvement. METHODS: The effect of an acute administration of different dosage of the aqueous extract (300 or 500 mg/kg) or AcOEt fraction (100, 300, 500 or 1000 mg/kg) of R. chalepensis was explored on two different models of acute seizure induction in mice, the PTZ and maximal electroshock (MES) tests. Behavioral and electrographic effects were quantified. Additionally, the possible involvement of the GABAA receptors was explored in the presence of picrotoxin (a non-competitive antagonist of the GABAA receptor). RESULTS: AcOEt fraction of R. chalepensis was more efficient than aqueous extract to reduce the incidence of tonic-clonic seizures and mortality in a significant and dose-dependent manner in both the PTZ and MES tests. This anticonvulsant effect was not abolished in the presence of picrotoxin. The EEG spectral power analysis revealed that aqueous extract decreased alpha and beta power, while AcOEt fraction decreased alpha and gamma power confirming previous findings of its depressant effect in the central nervous system. It is important to mention that the highest dosage of the AcOEt (1000 mg/kg) produced a severe suppression or isoelectric EEG activity (EEG flattening), recognized as a comatose state, suggesting a neurotoxic effect at this dosage. CONCLUSION: Our data reinforce that depressant and anticonvulsant effects of R. chalepensis depend in part on the presence of constituents from medium polarity. We also found that anticonvulsant effect is not mediated by GABAA receptors. In addition, cautious is emphasized when high doses of this natural product are used in traditional medicine since it might produce neurotoxic effects.

Contribution of GABAA, Glycine, and Opioid Receptors to Sacral Neuromodulation of Bladder Overactivity in Cats.

In α-chloralose-anesthetized cats, we examined the role of GABAA, glycine, and opioid receptors in sacral neuromodulation-induced inhibition of bladder overactivity elicited by intravesical infusion of 0.5% acetic acid (AA). AA irritation significantly (P < 0.01) reduced bladder capacity to 59.5 ± 4.8% of saline control. S1 or S2 dorsal root stimulation at threshold intensity for inducing reflex twitching of the anal sphincter or toe significantly (P < 0.01) increased bladder capacity to 105.3 ± 9.0% and 134.8 ± 8.9% of saline control, respectively. Picrotoxin, a GABAA receptor antagonist administered i.v., blocked S1 inhibition at 0.3 mg/kg and blocked S2 inhibition at 1.0 mg/kg. Picrotoxin (0.4 mg, i.t.) did not alter the inhibition induced during S1 or S2 stimulation, but unmasked a significant (P < 0.05) poststimulation inhibition that persisted after termination of stimulation. Naloxone, an opioid receptor antagonist (0.3 mg, i.t.), significantly (P < 0.05) reduced prestimulation bladder capacity and removed the poststimulation inhibition. Strychnine, a glycine receptor antagonist (0.03-0.3 mg/kg, i.v.), significantly (P < 0.05) increased prestimulation bladder capacity but did not reduce sacral S1 or S2 inhibition. After strychnine (0.3 mg/kg, i.v.), picrotoxin (0.3 mg/kg, i.v.) further (P < 0.05) increased prestimulation bladder capacity and completely blocked both S1 and S2 inhibition. These results indicate that supraspinal GABAA receptors play an important role in sacral neuromodulation of bladder overactivity, whereas glycine receptors only play a minor role to facilitate the GABAA inhibitory mechanism. The poststimulation inhibition unmasked by blocking spinal GABAA receptors was mediated by an opioid mechanism.

Synthesis and Anticonvulsant Activity of N-(Substituted)-1-methyl-2,4-dioxo-1,2-dihydroquinazoline-3(4H)-carboxamides.

A series of new N-(substituted)-1-methyl-2,4-dioxo-1,2-dihydroquinazoline-3(4H)-carboxamides were designed, synthesized, and evaluated for their anticonvulsant activity. Most of the synthesized compounds exhibited potent anticonvulsant activities in the maximal electroshock (MES) and pentylenetetrazol (PTZ) test. The most promising compound 4c showed significant anticonvulsant activity with a protective index value of 3.58. The compounds 4a-c were also found to have encouraging anticonvulsant activity in the MES and PTZ screen when compared with the standard drugs, valproate and methaqualone. The same compounds were found to exhibit advanced anticonvulsant activity as well as lower neurotoxicity than the reference drugs.

GABAA receptor antagonism ameliorates behavioral and synaptic impairments associated with MeCP2 overexpression.

Methyl-CpG-binding protein 2 (MeCP2) is a ubiquitously expressed transcriptional regulator with functional importance in the central nervous system. Loss-of-function mutations in MECP2 results in the neurodevelopmental disorder, Rett syndrome, whereas increased expression levels are associated with the neurological disorder, MECP2 duplication syndrome. Previous characterization of a mouse line overexpressing Mecp2 demonstrated that this model recapitulated key behavioral features of MECP2 duplication syndrome with specific deficits in synaptic plasticity and neurotransmission. Alterations in excitation/inhibition balance have been suggested to underlie neurodevelopmental disorders with recent data suggesting that picrotoxin (PTX), a GABAA receptor antagonist, rescues certain behavioral and synaptic phenotypes in a mouse model of Down syndrome. We therefore examined whether a similar treatment regimen would impact the behavioral and synaptic phenotypes in a mouse model of MECP2 duplication syndrome. We report that chronic treatment with low doses of PTX ameliorates specific behavioral phenotypes, including motor coordination, episodic memory impairments, and synaptic plasticity deficits. These findings suggest that GABAA receptor antagonists may offer a possible therapeutic target for the treatment of MECP2 duplication syndrome.

Anticonvulsant activity of DNS II fraction in the acute seizure models.

AIM OF THE STUDY: Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice. MATERIALS AND METHODS: Different doses (60, 65 and 70mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90mg/kg, s.c. and picrotoxin 3.15mg/kg, s.c.) were used. The mice were observed 45-90min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100mg/kg, i.p.) were tested in the MES test. RESULTS: The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5mg/kg, i.p. and phenytoin 20mg/kg, i.p.). CONCLUSIONS: These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile.

Epilepsy and cognitive impairments in Alzheimer disease.

Alzheimer disease (AD) is associated with cognitive decline and increased incidence of seizures. Seizure activity in AD has been widely interpreted as a secondary process resulting from advanced stages of neurodegeneration, perhaps in combination with other age-related factors. However, recent findings in animal models of AD have challenged this notion, raising the possibility that aberrant excitatory neuronal activity represents a primary upstream mechanism that may contribute to cognitive deficits in these models. The following observations suggest that such activity may play a similar role in humans with AD: (1) patients with sporadic AD have an increased incidence of seizures that appears to be independent of disease stage and highest in cases with early onset; (2) seizures are part of the natural history of many pedigrees with autosomal dominant early-onset AD, including those with mutations in presenilin-1, presenilin-2, or the amyloid precursor protein, or with duplications of wild-type amyloid precursor protein; (3) inheritance of the major known genetic risk factor for AD, apolipoprotein E4, is associated with subclinical epileptiform activity in carriers without dementia; and (4) some cases of episodic amnestic wandering and disorientation in AD are associated with epileptiform activity and can be prevented with antiepileptic drugs. Here we review recent experimental data demonstrating that high levels of beta-amyloid in the brain can cause epileptiform activity and cognitive deficits in transgenic mouse models of AD. We conclude that beta-amyloid peptides may contribute to cognitive decline in AD by eliciting similar aberrant neuronal activity in humans and discuss potential clinical and therapeutic implications of this hypothesis.

GABA(A) receptor-mediated acceleration of aging-associated memory decline in APP/PS1 mice and its pharmacological treatment by picrotoxin.

Advanced age and mutations in the genes encoding amyloid precursor protein (APP) and presenilin (PS1) are two serious risk factors for Alzheimer's disease (AD). Finding common pathogenic changes originating from these risks may lead to a new therapeutic strategy. We observed a decline in memory performance and reduction in hippocampal long-term potentiation (LTP) in both mature adult (9-15 months) transgenic APP/PS1 mice and old (19-25 months) non-transgenic (nonTg) mice. By contrast, in the presence of bicuculline, a GABA(A) receptor antagonist, LTP in adult APP/PS1 mice and old nonTg mice was larger than that in adult nonTg mice. The increased LTP levels in bicuculline-treated slices suggested that GABA(A) receptor-mediated inhibition in adult APP/PS1 and old nonTg mice was upregulated. Assuming that enhanced inhibition of LTP mediates memory decline in APP/PS1 mice, we rescued memory deficits in adult APP/PS1 mice by treating them with another GABA(A) receptor antagonist, picrotoxin (PTX), at a non-epileptic dose for 10 days. Among the saline vehicle-treated groups, substantially higher levels of synaptic proteins such as GABA(A) receptor alpha1 subunit, PSD95, and NR2B were observed in APP/PS1 mice than in nonTg control mice. This difference was insignificant among PTX-treated groups, suggesting that memory decline in APP/PS1 mice may result from changes in synaptic protein levels through homeostatic mechanisms. Several independent studies reported previously in aged rodents both an increased level of GABA(A) receptor alpha1 subunit and improvement of cognitive functions by long term GABA(A) receptor antagonist treatment. Therefore, reduced LTP linked to enhanced GABA(A) receptor-mediated inhibition may be triggered by aging and may be accelerated by familial AD-linked gene products like Abeta and mutant PS1, leading to cognitive decline that is pharmacologically treatable at least at this stage of disease progression in mice.

[Picrotoxin in the treatment of Menière's disease]. / Picrotoxin in der Therapie des Morbus Menière.

OBJECTIVE: In medical long-term treatment of Menière's disease picrotoxin suppositories are an uncommon method of prophylaxis. In spite of its empirical benefit in clinical use and its lack of side effects, there are few clinical studies about the therapeutical effect of picrotoxin. In this study we evaluate the effectiveness of picrotoxin compared to the therapy with betahistine in Menière's disease. MATERIAL AND METHODS: In a prospective clinical trial we examined 41 patients, 18 of them were treated with betahistine 3x12 mg, 23 had a therapy with picrotoxin-suppositories at 0.001 g three times a week. Frequency and intensity of the vertigo attacks were evaluated before and under treatment. Mean follow up time was 12 months. RESULTS: In both groups a reduction of the attacks' frequency and intensity could be noticed, which was statistically significant for all the two groups. Thus, in the course of the treatment we observed a significant stronger effectiveness of picrotoxin, regarding the frequency and intensity of vertigo attacks. Discussing our own results we review the state of the art in medical long-term treatment in Menière's disease. CONCLUSION: Because of its clinical benefit and the lack of side effects Picrotoxin is a reasonable alternative in medical long- term treatment of Menière's disease, which should have an important role in the treatment cascade.

Gabapentin attenuates acute hypoxic stress-induced behavioral alterations and oxidative damage in mice: possible involvement of GABAergic mechanism.

The effect of gabapentin has been investigated on acute hypoxic stress-induced behavioral alterations and oxidative damage in mice. Mice were subjected to hypoxia for 2 hr. Treatment with gabapentin (50 and 100 mg/kg) significantly increased ambulatory movements, exerted anti-anxiety like effect and reduced oxidative damage in mice subjected to acute hypoxic stress. Treatment with picrotoxin (1.0 mg/kg) per se had no significant effect on behavioral and biochemical parameters of stressed mice. Treatment with muscimol (0.05 mg/kg) per se significantly increased the locomotor activity of stressed mice, exerted significant anti anxiety effect and significantly reduced the oxidative damage. Further, pretreatment with picrotoxin (1.0 mg/kg) significantly blocked whereas pretreatment with muscimol (0.05 mg/kg) significantly potentiated the neuroprotective effect of gabapentin. These results suggest that gabapentin produces its neuroprotective effect in mice subjected to acute hypoxic stress through GABA(A) receptor mechanism.

Pharmacotherapy for cognitive impairment in a mouse model of Down syndrome.

Ts65Dn mice, a model for Down syndrome, have excessive inhibition in the dentate gyrus, a condition that could compromise synaptic plasticity and mnemonic processing. We show that chronic systemic treatment of these mice with GABAA antagonists at non-epileptic doses causes a persistent post-drug recovery of cognition and long-term potentiation. These results suggest that over-inhibition contributes to intellectual disabilities associated with Down syndrome and that GABAA antagonists may be useful therapeutic agents for this disorder.

'Complementary ENT': a systematic review of commonly used supplements.

OBJECTIVE: To assess the evidence surrounding the use of certain complementary supplements in otolaryngology. We specifically focussed on four commonly used supplements: spirulina, Ginkgo biloba, Vertigoheel and nutritional supplements (cod liver oil, multivitamins and pineapple enzyme). MATERIALS AND METHODS: A systematic review of the English and foreign language literature. INCLUSION CRITERIA: in vivo human studies. EXCLUSION CRITERIA: animal trials, in vitro studies and case reports. We also excluded other forms of 'alternative medicine' such as reflexology, acupuncture and other homeopathic remedies. RESULTS: Lack of common outcome measures prevented a formal meta-analysis. Three studies on the effects of spirulina in allergy, rhinitis and immunomodulation were found. One was a double-blind, placebo, randomised, controlled trial (RCT) of patients with allergic rhinitis, demonstrating positive effects in patients fed spirulina for 12 weeks. The other two studies, although non-randomised, also reported a positive role for spirulina in mucosal immunity. Regarding the use of Ginkgo biloba in tinnitus, a Cochrane review published in 2004 showed no evidence for this. The one double-blind, placebo-controlled trial that followed confirmed this finding. Regarding the use of Vertigoheel in vertigo, two double-blind RCTs and a meta-analysis were identified. The first RCT suggested that Vertigoheel was equally effective in reducing the severity, duration and frequency of vertigo compared with betahistine. The second RCT suggested that Vertigoheel was a suitable alternative to G. biloba in the treatment of atherosclerosis-related vertigo. A meta-analysis of only four clinical trials confirms that Vertigoheel was equally effective compared with betahistine, G. biloba and dimenhydrinate. Regarding multivitamins and sinusitis, two small paediatric pilot studies reported a positive response for chronic sinusitis and otitis media following a course of multivitamins and cod liver oil. Regarding bromelain (pineapple enzyme) and sinusitis, one randomised, multicentre trial including 116 children compared bromelain monotherapy to bromelain with standard therapy and standard therapy alone, for the treatment of acute sinusitis. The bromelain monotherapy group showed a faster recovery compared with the other groups. CONCLUSION: The positive effects of spirulina in allergic rhinitis and of Vertigoheel in vertigo are based on good levels of evidence, but larger trials are required. There is overwhelming evidence that G. biloba may play no role in tinnitus. There is limited evidence for the use of multivitamins in sinus symptoms, and larger randomised trials are required.

Microcirculatory effects of a homeopathic preparation in patients with mild vertigo: an intravital microscopic study.

The effects of the homeopathic preparation Vertigoheel on variables related to microcirculation were investigated using vital microscopy techniques in patients with vestibular vertigo. In a non-randomized, open study, 16 patients given Vertigoheel were compared with 16 untreated patients. Measurements were carried out in two areas (defined by selecting 60 blood-cell perfused nodal points of arterioles, venules, and capillaries with a mean diameter > or = 40 microm): the cuticulum/subcuticulum of the inside left lower arm and an area 5 mm behind the left earlobe. After 12 weeks of treatment, patients receiving the homeopathic preparation exhibited an increased number of nodal points, increased flow rates of erythrocytes in both arterioles and venules, increased vasomotion, and a slight reduction in hematocrit vs. baseline. None of these changes were observed in the control group and the differences between treatment groups were statistically significant. Partial oxygen pressure increased significantly in the Vertigoheel group compared with the control group. In addition, in Vertigoheel patients, significantly increased numbers of cell-wall adhering leucocytes were observed, accompanied by increased local concentrations of the adhesion molecules ICAM-1. The microcirculatory changes were associated with a reduction in the severity of vertigo in the actively treated patients, both as assessed by the treating physician and by the patients themselves. The data support a pharmacological effect on microcirculation from the treatment.

The homeopathic preparation Vertigoheel versus Ginkgo biloba in the treatment of vertigo in an elderly population: a double-blinded, randomized, controlled clinical trial.

OBJECTIVE: Alternative medical practices are common in the treatment of vertigo. This study compared the effects of Ginkgo biloba treatment with the homeopathic remedy Vertigoheel (Biologische Heilmittel Heel GmbH, Baden-Baden, Germany). DESIGN: Randomized, double-blinded, parallel group study. SUBJECTS: One hundred and seventy (170) patients, ages 60-80 years, with atherosclerosis-related vertigo. INTERVENTIONS: Patients were randomly allocated to receive treatment with either Vertigoheel (n = 87) or G. biloba (n = 83). OUTCOME MEASURES: The results were analyzed for the non-inferiority of Vertigoheel to G. biloba on the combined endpoint of changes from baseline to week 6 in dizziness score (assessed by questionnaire), frequency, duration, and intensity of vertigo episodes (recorded in patient diaries). RESULTS: Both treatments improved vertigo status. From a baseline mean value of 26.1 +/- 5.2 (on a 50-point scale) in the Vertigoheel group, the dizziness questionnaire score improved by -10.6 +/- 10.0, and by -10.7 +/- 9.0 from 25.8 - 4.7 in the G. biloba group. Statistical analysis of this endpoint showed that Vertigoheel was not inferior to G. biloba. The 95% confidence interval for the difference between treatment did not reach the inferiority threshold of 0.36 at any of the time points tested. The results were supported by the results of a line walking test, Unterberger's stepping test, and patient and physician global assessments of therapeutic effect. Both treatments were well tolerated. CONCLUSIONS: Vertigoheel is an appealing alternative to established G. biloba therapy for atherosclerosis-related vertigo.

Treatment of vertigo with a homeopathic complex remedy compared with usual treatments: a meta-analysis of clinical trials.

The increasing interest in alternative medical practices has led to a number of controlled studies on herbal and homeopathic agents. This paper presents the results of a meta-analysis of four recent clinical trials evaluating the homeopathic preparation Vertigoheel (VH) compared with usual therapies (betahistine, Ginkgo biloba extract, dimenhydrinate) for vertigo in a total of 1388 patients. Two trials were observational studies and the other two were randomised double-blind controlled trials. The duration of treatment (6-8 weeks) and dosage were comparable in all studies. Treatments were evaluated for the variables "number of vertigo episodes", "intensity of episodes" and "duration of episodes". As the studies differed in the age of patients and in the baseline values of vertigo, the individual reductions of number, intensity and duration of episodes were adjusted on equal age and baseline values (total means). An analysis of variance (with studies as random effects) showed no relevant influence of studies on the adjusted reductions and no relevant interaction between studies and treatment effects. The meta-analysis of all four trials showed equivalent reductions with VH and with control treatment: mean reduction of the number of daily episodes 4.0 for VH and 3.9 for control (standard error 0.11 for both groups); mean reduction of the duration (on a scale 0-4) for VH 1.1 and for the control 1.0 (standard error 0.03 for both groups); mean reduction of the intensity (on a scale 0-4) for VH 1.18 and for the control 1.8 (standard error 0.03 for both groups). In the non-inferiority analysis from all trials, VH was non-inferior in all variables. The results show the applicability of meta-analyses on the data from studies with homeopathicdrugs and support the results from the individual studies indicating good efficacy and tolerability of VH in patients with vertigo.