Peripheral Infection after Traumatic Brain Injury Augments Excitability in the Perilesional Cortex and Dentate Gyrus

Peripheral infections occur in up to 28% of patients with traumatic brain injury (TBI), which is a major etiology for structural epilepsies. We hypothesized that infection occurring after TBI acts as a “second hit” and facilitates post-traumatic epileptogenesis. Adult male Sprague–Dawley rats were subjected to lateral fluid-percussion injury or sham-operation. At 8 weeks post-injury, rats were treated with lipopolysaccharide (LPS, 5 mg/kg) to mimic Gram-negative peripheral infection. T2-weighted magnetic resonance imaging was used to detect the cortical lesion type (small focal inflammatory [TBIFI] vs. large cavity-forming [TBICF]). Spontaneous seizures were detected with video-electroencephalography, and seizure susceptibility was determined by the pentylenetetrazole (PTZ) test. Post-PTZ neuronal activation was assessed using c-Fos immunohistochemistry. LPS treatment increased the percentage of rats with PTZ-induced seizures among animals with TBIFI lesions (p < 0.05). It also increased the cumulative duration of PTZ-induced seizures (p < 0.01), particularly in the TBIFI group (p < 0.05). The number of c-Fos immunopositive cells was higher in the perilesional cortex of injured animals compared with sham-operated animals (p < 0.05), particularly in the TBI-LPS group (p < 0.05). LPS treatment increased the percentage of injured rats with bilateral c-Fos staining in the dentate gyrus (p < 0.05), particularly in the TBIFI group (p < 0.05). Our findings demonstrate that peripheral infection after TBI increases PTZ-induced seizure susceptibility and neuronal activation in the perilesional cortex and bilaterally in the dentate gyrus, particularly in animals with prolonged perilesional T2 enhancement. Our data suggest that treatment of infections and reduction of post-injury neuro-inflammation are important components of the treatment regimen aiming at preventing epileptogenesis after TBI.

Synthesis and pharmacological evaluation of novel naphthoquinone derivatives containing 1,2,4-triazine and 1,2,4-triazole moieties of methylene blue on the surface of a "core–shell" type catalyst for the Fenton system

Novel naphthoquinone derivatives bearing 1,2,4-triazine- (4a–b) and 1,2,4-triazole (5a–e) pharmacophores have been synthesized; their structure was confirmed by electrospray ionization mass spectrometry, 1H NMR, 13C NMR, IR spectroscopies and elemental analysis. The obtained heterocyclic compounds were estimated for their anticonvulsant activity on models of chemical- and electrical-induced seizures in pentylenetetrazole (PTZ) and maximal electroshock (MES) tests, respectively. Forced swimming test was used to evaluate the antidepressant effect of the naphthoquinone derivatives under study. Compounds 4a–b and 5a–e (100 mg kg–1) demonstrated anticonvulsant action comparable with valproic acid in PTZ-test and prevented the death of 100% of mice in MES model at 3 h and 24 h after oral administration. Moreover, these derivatives showed prolonged antidepressant-like properties, significantly reducing the duration of immobility time in comparison with the reference drug amitriptyline.

Anticonvulsant Activity, Molecular Modeling and Synthesis of Spirooxindole-4H-Pyran Derivatives using a Novel Reusable Organocatalyst

Fifteen derivatives of spirooxindole-4H-pyran (A1-A15) were subjected to evaluate through intravenous infusion of pentylenetetrazole (PTZ) induced epilepsy mouse models. Four doses of the compounds (20, 40, 60, 80 mg/kg) were tested in comparison to diazepam as positive control. The resulted revealed that compounds A3 and A12 were the most active compounds and indicated significant anticonvulsant activity in the PTZ test. The tested compounds were prepared via a multicomponent reaction using graphene oxide (GO) based on the 1-(2-aminoethyl) piperazine as a novel heterogeneous organocatalyst. The prepared catalyst (GO-A.P.) was characterized using some diverse microscopic and spectroscopic procedures as well. The results showed high catalytic activity of the catalyst in the synthesis of spirooxindole-4H-pyran derivatives. The GO-A.P. catalyst was reusable at least for 5 times with no significant decrease in its catalytic action. In silico assessment of physico chemical activity of all compounds also were done which represented appropriate properties. Finally, molecular docking study was performed to achieve their binding affinities as γ-aminobutyric acid-A (GABA‐A) receptor agonists as a plausible mechanism of their anticonvulsant action. Binding free energy values of the compounds represented strongly matched with biological activity.

Evaluation of Anticonvulsant Properties of Methanol Aerial Extract of Bryophyllum Pinnatum (Lam.) Oken (Crassulaceae) In Mice and Chicks

Background: Bryophyllum pinnatum is an environmental weed from the Crassulaceae family that is often used to treat convulsion, hypertension, diarrhea, insect bites, asthma and other ailments.Objectives: To evaluate the anticonvulsant potential of methanol aerial extract of Bryophyllum pinnatum plant in mice and chicks.Materials and Methods: The anticonvulsant potential was studied using Maximal electroshock Test (MEST) and pentylenetetrazol (PTZ) test in one day old chicks and mice at 250, 500 and 1000 mg/kg body weight of the extract i.p respectively. Positive control drugs used were sodium valproate (200 mg/kg) and phenytoin (20 mg/kg) in PTZ and MEST respectively while distilled water (10 ml/kg) i.p was used as negative control in all experiments.Results: The intraperitoneal LD50 of the extract was found to be greater than 5000 mg/kg body weight with an indication that the extract is relatively safe. Significant (p ≤ 0.05) prolongation of the mean onset of seizures was recorded with the extract at 1000 mg/kg body weight compared with normal saline treated group in PTZ induced seizures. Bryopyllum pinnatum methanol aerial extract also significantly reduced the mean recovery time of seizures at doses 500 and 1000 mg/kg induced by MEST when compared with normal saline treated group. Conversely, a significant (p ≤ 0.05) delay in the mean onset of seizures was recorded with standard drugs, sodium valproate (200 mg/kg) and phenytoin (20 mg/kg) in PTZ and MEST respectively.Conclusion: Methanol extract of the aerial part of Bryophyllum pinnatum possesses anticonvulsant activities.

In vitro and In vivo Anticonvulsant Effect of Hydroalcoholic Extracts of Clutia abyssinica in Mice Model

Background: Epilepsy is a chronic disorder of the brain that affects people of all ages worldwide. In the search of safe and effective antiepileptics traditional treatment practices are one area of research to obtain novel molecules. Research is also needed to validate and standardize the traditional claim. Clutia abyssinica leaves were one of the medicinal plants claimed for use against epilepsy and evil eye and other diseases in different parts of Ethiopia. But there was no scientific research evidence for the claimed use of the plant. Therefore this work was designed to evaluate the anticonvulsant effect of hydroalcoholic extract of Clutia abyssinica leaves. Methods: The dry residue of the plant extract was used for the test. In vitro 0Mg2+ mice model at dose 0.7 mg/kg of extract, diazepam (3μM) and untreated brain slice groups were used to compare the presence of seizure like event (SLE). In vivo pentylenetetrazol (PTZ) model with 85 mg/kg subcutaneously was used to compare the seizure onset time with two extract doses and diazepam 5 mg/kg. The data was presented with mean± standard error. In maximum electric shock (MES) model 54 mA was passed for 0.2 second transauricularly in mice. The mean time of hind limb extension was recorded for doses 400 mg/kg and 800mg/kg of the extract and 10 mg/kg phenytoin. The means were compared for statistical significance using one way ANOVA post hoc LSD whereas proportions were compared using Fishers exact test with P-value < .05. Results: In vitro anticonvulsant tests C. abyssinica extract effect was not statistically significant compared to negative control (P>0.05).A positive control using the known anticonvulsant diazepam (3μM), showed significant anticonvulsant activity (P<0.05). The in vivo PTZ test showed no statistically significant effect in plant extract at all dose levels (P>0.05). In the in vivo MES test the extract of Clutia abyssinica both low and higher dose didn't show statistically significant effect (P>0.05) compared with the negative control. But the extract improved survival (p<0.05). The qualitative secondary metabolite test evidenced the presence of alkaloids, cardiac glycosides, flavanoids, phenols, saponins, sterols and terpeoids in Clutia abyssinica extract. Conclusion: The hydroalcoholic crude extract result of the C. abyssinica as anticonvulsant is weak based on the models used in this study. For most of the local preparation are mixes of different plants it may have synergistic action with other plants. Or it may have action with other models of chronic epilepsy.

Intranasal Allopregnanolone Confers Rapid Seizure Protection: Evidence for Direct Nose-to-Brain Delivery

Allopregnanolone, a positive modulator of GABAA receptors with antiseizure activity, has potential in the treatment of seizure emergencies. Instillation of allopregnanolone in 40% sulfobutylether-β-cyclodextrin into the nose in mice rapidly elevated the seizure threshold in the timed intravenous pentylenetetrazol (ED50, 5.6 mg/kg), picrotoxin (ED50, 5.9 mg/kg), and bicuculline seizure tests. The effect peaked at 15 min, decayed over 1 h, and was still evident in some experiments at 6 h. Intranasal allopregnanolone also delayed the onset of seizures in the maximal PTZ test. At an allopregnanolone dose (16 mg/kg) that conferred comparable effects on seizure threshold as the benzodiazepines midazolam and diazepam (both at doses of 1 mg/kg), allopregnanolone caused minimal sedation or motor toxicity in the horizontal screen test whereas both benzodiazepines produced marked behavioral impairment. In addition, intranasal allopregnanolone failed to cause loss-of-righting reflex in most animals, but when the same dose was administered intramuscularly, all animals became impaired. Intranasal allopregnanolone (10 mg/kg) caused a rapid increase in brain allopregnanolone with a Tmax of ~5 min after initiation of the intranasal delivery. High levels of allopregnanolone were recovered in the olfactory bulb (Cmax, 16,000 ng/mg) whereas much lower levels (Cmax, 670 ng/mg) were present in the remainder of the brain. We conclude that the unique ability of intranasal allopregnanolone to protect against seizures without inducing behavioral adverse effects is due in part to direct nose-to-brain delivery, with preferential transport to brain regions relevant to seizures. Benzodiazepines are commonly administered intranasally for acute seizure therapy, including for the treatment of acute repetitive seizures, but are not transported from nose-to-brain. Intranasal allopregnanolone acts with greater speed, has less propensity for adverse effects, and has the ability to overcome benzodiazepine refractoriness. This is the first study demonstrating rapid functional central nervous system activity of a nose-to-brain-delivered steroid. Intranasal delivery circumvents the poor oral bioavailability of allopregnanolone providing a route of administration permitting its evaluation as a treatment for diverse neuropsychiatric indications.

Anticonvulsant Effect of Antiaris toxicaria (Pers.) Lesch. (Moraceae) Aqueous Extract in Rodents

Antiaris toxicaria (Moraceae) was evaluated for anticonvulsant activity in rodents. Animal models used include maximal electroshock test (MEST); pentylenetetrazole-induced (PTZ) convulsions; picrotoxin-induced (PCT) convulsions; strychnine- (STR-) and 4-aminopyridine-induced convulsions. Increase in latency to seizures as well as reduction in duration and frequency of seizures indicated anticonvulsant activity. The extract was more effective in all models used except the maximal electroshock test and strychnine-induced convulsions. Antiaris toxicaria aqueous extract (200, 400, and 800 mg kg−1) significantly () shortened the duration of convulsions in PTZ- and PCT-induced seizures. Delay in the onset of convulsions in the two tests was significant (). Reduction in the frequency of seizures was also significant () in both tests. Antiaris further delayed the onset of seizures in 4-aminopyridine model while producing 75% protection against death in mice. Diazepam (0.1, 0.3, and 1 mg kg−1), carbamazepine (3, 10, and 30 mg kg−1), and sodium valproate (100–400 mg kg−1) were used as reference anticonvulsant drugs for various models. Flumazenil blocked the effect of the extract in the PTZ test significantly suggesting that Antiaris toxicaria may be acting by enhancing the effects of the GABAergic system. Antiaris toxicaria aqueous extract therefore possesses anticonvulsant activity.

Aislamiento y determinación de estructura química de principios activos presentes en Eugenia uniflora, centrado en los compuestos solubles en metanol

La epilepsia es un grupo heterogéneo de desordenes neurológicos que afecta al 3% de la población mundial. El 30% de los pacientes epilépticos no consigue controlar sus convulsiones con las drogas antiepilépticas (AEDs) disponibles. Existe por lo tanto la necesidad de buscar nuevas AEDs que sean más eficaces y posean menor toxicidad, siendo los productos naturales una alternativa válida como fuente de nuevas estructuras. Eugenia uniflora L (Mirtaceae) es un arbusto ramificado y globoso, utilizado en la medicina tradicional en Brasil, Paraguay y NO de Argentina, sus nombres más comunes son “pitanga” y “ñangapirí” Las hojas desecadas de Eugenia uniflora fueron secadas y molidas. 250 g del polvo fue extraído sucesivamente con hexano y metanol por maceración en frío y se preparó una infusión y un cocimiento (según FNA VI Ed.) del polvo del material vegetal al 5 % y 10% P/V, respectivamente. Los extractos hexánico, metanólico, la infusión y el cocimiento fueron evaluados de acuerdo al Anticonvulsant Drug Development (ADD). Los extractos fueron evaluados en su actividad anticonvulsiva, frente al MES test y PTZ test. El extracto metanólico fue fraccionado por distintas técnicas cromatográficas y las fracciones fueron analizadas por cromatografía líquida de alta resolución (HPLC-DAD) y cromatografía gaseosa acoplada a espectrometría de masas (CG- MS). El extracto metanólico demostró una actividad anticonvulsiva importante, como así también la fracción obtenida por precipitación que presentó una actividad anticonvulsiva 50% efectiva, dando hasta los 30 minutos 75 % efectividad, aumentando el umbral de las convulsiones clónicas inducidas por la administración de PTZsc. Se lograron identificar cuatro compuestos en la fracción activa de Eugenia uniflora.