Electroencephalographic profile of Salvia amarissima Ortega and amarisolide A in the absence and presence of PTZ-induced seizures in mice.

Salvia amarissima Ortega is a plant used in traditional medicine to treat CNS's affections. Despite its depressant properties in anxiety and fibromyalgia, there is no scientific evidence about its capability to control seizure activity. This study aimed to investigate the effects of the S. amarissima aqueous extract (SAAE) and its metabolite amarisolide A (AMA) on the electrocorticographic (ECoG) activity. The ECoG profiles were previously and concurrently analyzed to the pentylenetetrazole (85 mg/kg, i.p.)-induced seizure behavior after thirty min of the administration of several doses of the SAAE (1, 10, 30, and 100 mg/kg, i.p.) and two doses of AMA (0.5 and 1 mg/kg, i.p.). A dosage of AMA (1 mg/kg,i.p.) was selected to explore a possible mechanism of action by using antagonists of inhibitory receptors such as GABAA (picrotoxin, 1 mg/kg, i.p.) or 5-HT1A of serotonin (WAY100635, 1 mg/kg, i.p.). Significant changes in the frequency bands and the spectral power were observed after the treatment alone. Additionally, SAAE and AMA produced significant and dose-dependent anticonvulsant effects by reducing the incidence and severity of seizures and increasing latency or survival. Both antagonists prevented the effects of AMA in the severity score of seizures and survival during the tonic-clonic seizures. In conclusion, our preclinical data support that S. amarissima possesses anticonvulsant properties, in part due to the presence of amarisolide A, mediated by different inhibitory mechanisms of action. Our scientific evidence suggests that this Salvia species and amarisolide A are potential neuroprotective alternatives to control seizures in epilepsy therapy.

Terminalia arjuna bark extract attenuates picrotoxin-induced behavioral changes by activation of serotonergic, dopaminergic, GABAergic and antioxidant systems.

Stress and emotion are associated with several illnesses from headaches to heart diseases and immune deficiencies to central nervous system. Terminalia arjuna has been referred as traditional Indian medicine for several ailments. The present study aimed to elucidate the effect of T. arjuna bark extract (TA) against picrotoxin-induced anxiety. Forty two male Balb/c mice were randomly divided into six experimental groups (n = 7): control, diazepam (1.5 mg·kg-1), picrotoxin (1 mg·kg-1) and three TA treatemt groups (25, 50, and 100 mg/kg). Behavioral paradigms and PCR studies were performed to determine the effect of TA against picrotoxin-induced anxiety. The results showed that TA supplementation increased locomotion towards open arm (EPM) and illuminated area (light-dark box test), and increased rearing frequency (open field test) in a dose dependent manner, compared to picrotoxin (P < 0.05). Furthermore, TA increased number of licks and shocks in Vogel's conflict. PCR studies showed an up-regulation of several genes, such as BDNF, IP3, D2L, CREB, GABAA, SOD, GPx, and GR in TA administered groups. In conclusion, alcoholic extract of TA bark showed protective activity against picrotoxin in mice by modulation of genes related to synaptic plasticity, neurotransmitters, and antioxidant enzymes.

p-Coumaric acid activates the GABA-A receptor in vitro and is orally anxiolytic in vivo.

The increasing prevalence and social burden of subclinical anxiety in the western world represents a significant psychosocial and financial cost. Consumers are favouring a more natural and nonpharmacological approach for alleviating the effects of everyday stress and anxiety. The gamma-aminobutyric acid (GABA) receptor is the primary mediator of central inhibitory neurotransmission, and GABA-receptor agonists are well known to convey anxiolytic effects. Using an in vitro screening approach to identify naturally occurring phytochemical GABA agonists, we discovered the plant secondary metabolite p-coumaric acid to have significant GABAergic activity, an effect that could be blocked by co-administration of the specific GABA-receptor antagonist, picrotoxin. Oral administration of p-coumaric acid to rodents induced a significant anxiolytic effect in vivo as measured using the elevated plus paradigm, in line with the effects of oral diazepam. Given that p-coumaric acid is reasonably well absorbed following oral consumption in man and is relatively nontoxic, it may be suitable for the formulation of a safe and effective anxiolytic functional food.

Behavioral and antiepileptic effects of acute administration of the extract of the plant Cestrum nocturnum Lin (lady of the night).

Cestrum nocturnum is a garden shrub from the family Solanaceae and is used as a remedy for different health disorders. The aim of the present work was to investigate the potential neuropharmacological action profile of decoctions obtained from dry leaves of the plant. Decoctions were tested in different neuropharmacological models-Irwin test, exploratory behavior, tests for analgesia, isoniazid- and picrotoxin-induced convulsions, and maximal electroshock seizures-in mice, as well as in amphetamine-induced stereotypies and penicillin epileptic foci in rats. Decoctions of 1 and 5% (D1 and D5) induced restlessness, and the 30% decoction (D30) induced passivity. D5 and D30 reduced significantly exploratory behavior and amphetamine-induced stereotypies within a 3-hour observation period. The latter effect was apparent during the second 60 minutes. Decoctions reduced the amount of writhes induced by acetic acid in a dose-dependent manner, but were not effective in the hot plate model. The decoctions were not effective against pharmacologically induced convulsions. However, repeated administration of five doses of D5, at 1-hour intervals, reduced the amplitude of penicillin-induced epileptic spikes in both primary and secondary foci, in curarized rats. Taken together, the results suggest that C. nocturnum possesses active substances with analgesic activity provided through a peripheral action mechanism, in parallel with some psychoactive activity that does not fit well the neuropharmacological action profile of known reference neurotropic drugs.

Anticonvulsant effect of Persea americana Mill (Lauraceae) (Avocado) leaf aqueous extract in mice.

Various morphological parts of Persea americana Mill (Lauraceae) (avocado) are widely used in African traditional medicines for the treatment, management and/or control of a variety of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant effect of the plant's leaf aqueous extract (PAE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, Persea americana leaf aqueous extract (PAE, 100-800 mg/kg i.p.) significantly (p < 0.05-0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. The plant's leaf extract (PAE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only weakly antagonized bicuculline (BCL)-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that 'avocado' leaf aqueous extract (PAE) produces its anticonvulsant effect by enhancing GABAergic neurotransmission and/or action in the brain. The findings of this study indicate that Persea americana leaf aqueous extract possesses an anticonvulsant property, and thus lends pharmacological credence to the suggested ethnomedical uses of the plant in the management of childhood convulsions and epilepsy.

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.

Suppression of absence seizures by electrical and pharmacological activation of the caudal superior colliculus in a genetic model of absence epilepsy in the rat.

Activation of the superior colliculus has been shown to reproduce the antiepileptic effect of the inhibition of the substantia nigra reticulata. A circuit involving neurons of the caudal deep layers of the superior colliculus has been suggested to control brain stem convulsive seizures. The present study was designed to examine whether a similar circuit is also involved in the control of absence seizures. For this, activation of either the rostral or caudal parts of the deep and intermediate layers of the superior colliculus was applied in a genetic model of absence seizures in the rat (GAERS). Single-shock (5 s) electrical stimulation of the rostral and caudal superior colliculus interrupted ongoing spike-and-wave discharges at an intensity (antiepileptic threshold) significantly lower than the intensity inducing behavioral effects. At this intensity, no interruption of licking behavior was observed in water-deprived rats. Repeated stimulations (5 s on/5 s off) at the antiepileptic threshold reduced absence seizures only during the first 10 min. Bilateral microinjection of a GABA antagonist (picrotoxin, 33 pmol/side) significantly suppressed spike-and-wave discharges when applied in the caudal aspect of the superior colliculus. This antiepileptic effect appears dissociated from an anxiogenic effect, as tested in an elevated plus maze test. Finally, bilateral injection of picrotoxin (33 pmol/side) appeared more effective in the superficial and intermediate layers of the caudal superior colliculus, whereas such injections had only weak effects on absence seizures when applied in the deep layers. These results suggest that a specific population of neurons located in the intermediate and superficial layers of the caudal superior colliculus is involved in the inhibitory control of absence seizures. It may constitute an important relay for the control of absence seizures by the basal ganglia via the substantia nigra reticulata.

Efectos agudos del extracto de Ambrosia paniculata (Willd.) O.E. Schulz (artemisa) sobre diversos modelos de epilepsia experimental / Acute effects of the extract of Ambrosia paniculata (Willd.) O.E. Schulz (artemisa) on diverse models of experimental epilepsy

Se realizó una evaluación de la posible acción antiepiléptica de decocciones de hojas secas de Ambrosia paniculata mediante la administración aguda intraperitoneal en modelos de epilepsia experimental inducidos por isoniacida, picrotoxina, electrochoque (en ratones) y en el foco epiléptico inducido por la administración tópica cortical de penicilina, en ratas curarizadas. El extracto al 5 (por ciento) prolongó significativamente la latencia de aparición de las crisis y la muerte provocadas por isoniacida y picrotoxina, pero no las inducidas por electrochoque. El extracto al 5 (por ciento) redujo significativamente la amplitud de espigas del foco penicilínico. Estos resultados apoyaron o justificaron el empleo tradicional de esta planta en los trastornos convulsivos(AU)

Efectos agudos del extracto del Cestrum nocturnum (galán de noche) sobre diferentes modelos de epilepsia experimental / Acute effects of the extract from Cestrum nocturnum (night jessamine) on different models of experimental epilepsy

Se investiga la posible acción antiepiléptica de decocciones de hojas secas de C. nocturnum mediante la administración aguda intraperitoneal en modelos de epilepsia experimental inducidos por isoniacida, picrotoxina, electrochoque (en ratones) y en el foco epiléptico inducido por la administración tópica cortical de penicilina, en ratas curarizadas. El extracto al 30 (por ciento) prolongó significativamente la latencia de aparición de las crisis y la muerte provocadas por isoniacida, pero no las inducidas por electrochoque o picrotoxina. El extracto al 5 (por ciento) redujo significativamente la amplitud de espigas del foco penicilínico. Estos resultados apoyan o justifican el empleo tradicional de esta planta en los trastornos convulsivos(AU)

Frontal cortex leads other brain structures in generalised spike-and-wave spindles and seizure spikes induced by picrotoxin.

Generaliszed spike-and-wave (SW) spindles (5-7 Hz) associated with myoclonic jerks precede the occurrence of regular spikes (2-3 Hz) associated with convulsive seizure induced by picrotoxin. SW spindles occur spontaneously in rodent and cat under some experimental conditions and are considered to be models of human generalised epilepsy. These spindles have been proposed as being led by a thalamic pacemaker. To examine this possibility in picrotoxin-induced SW spindles and seizure spikes, we recorded EEG using chronically implant unipolar electrodes during intravenous picrotoxin infusion in freely behaving rat. The 6 EEG signals were digitally sampled at 1000 Hz. Linear correlation, spectral, coherence and phase analyses were undertaken to determine time differences (TDs) between EEG channels and the brain structure leading seizure activity. One frontal cortex led all other structures during SW spindles. TD between SW spindles in the leading frontal cortex (Fr1) and the contralateral Fr1 was 3.6 + / - 0.5 msec. All ipsilateral structures (hippocampus, thalamus, amygdala, caudate nucleus and occipital cortex) were delayed by more than 3 msec from Fr1 (intralaminar thalamic nuclei - by 6.3 + / - 0.9 msec). TDs of SW spindles between subcortical regions were less than 1.5 msec. Similar relationships with slightly smaller TDs were found with spikes during convulsive seizure except TDs between frontal cortices did not significantly differ from zero. We suggest that seizure activity induced by picrotoxin is led by one Fr1 during SW spindles and by both frontal cortices working as one system during convulsive seizure.