Methanol leaf extract of Paullinia pinnata exerts sleep-enhancing and anticonvulsant effects via a mechanism involving the GABAergic pathway.

PURPOSE: Leaf extracts of Paullinia pinnata L. (Sapindaceae) are used in ethnomedicine for the treatment of central nervous system-related diseases such as insomnia and epilepsy. We determined the bioactive constituents, sleep-enhancing and anti-convulsant potentials, and possible mechanisms of action of P. pinnata methanol leaf extract (PPME). METHODS: Gas Chromatography-Mass spectrometry (GC-MS) was used to identify the bioactive compounds in PPME. Adult Swiss albino mice were used. Oral LD50 was estimated before administering PPME at oral doses of 100, 200, and 400 mg/kg to test for sleep-enhancing and anticonvulsant properties. To evaluate the possible mechanisms involved, mice were pretreated for five days with isoniazid (NIH) a GABA synthesis inhibitor before re-evaluation of sleep-enhancing property. The activities of glutamic acid decarboxylase (GAD), superoxide dismutase (SOD), catalase (CAT), and the level of malondialdehyde (MAD) in the brain of mice were also evaluated after a 7-day treatment with the extract. RESULTS: Twenty-five phytochemical compounds were identified from GC-MS analysis with fatty acid esters of lauric and fumaric acids being the most abundant. The oral LD50 of PPME was estimated to be greater than 5000 mg/kg. Doses of PPME significantly (p < 0.001) reduced sleep latency and increased the duration of sleep of phenobarbital-treated mice. Except for 100 mg/kg, the doses also significantly protected mice against maximum electroshock (p < 0.001) and pentylenetetrazole (p < 0.05) but not strychnine-induced convulsions. Pretreatment with isoniazid (INH) almost completely reversed the sleep-enhancing effects of PPME. The activities of GAD, SOD, and CAT, and level of MDA in brains of the mice were significantly (p < 0.001) increased by doses of PPME administered for five days. CONCLUSION: The extract possesses sleep-enhancing and anticonvulsant properties which depend on increased level of GABA in the brain. Its antioxidant action may be neuroprotective against free radicals-induced damage.

Creatine attenuates seizure severity, anxiety and depressive-like behaviors in pentylenetetrazole kindled mice.

Epilepsy has been associated with several behavioral changes such as depression and anxiety while some antiepileptic drugs can precipitate psychiatric conditions in patients. This study evaluated the ameliorative effect of creatine on seizure severity and behavioral changes in pentylenetetrazole (PTZ) kindled mice. Mice were kindled by administering sub-convulsive doses of PTZ (35 mg/kg i.p.) at interval of 48 h. The naïve group (n = 7) constituted group 1, while successfully kindled mice were randomly assigned to five groups (n = 7). Group II served as vehicle treated group; groups III-V were treated with creatine 75, 150, and 300 mg/kg/day, p.o; Group V was given 25 mg/kg/day of phenytoin p.o. The treatment was for 15 consecutive days. The intensity of convulsion was scored according to a seven-point scale ranging from stage 0-7. Tail suspension test (TST) and Elevated plus maze (EPM) were utilized to assess depression and anxiety-like behavior respectively. After behavioral evaluation on day 15th, their brain was isolated and assayed for catalase, superoxide dismutase, reduced glutathione, and malondialdehyde. There was a significant (p < 0.05) reduction in the seizure scores, anxiety and depression-like behaviors in mice from the 5th day of treatment. The antioxidant assays revealed significant (p < 0.05) increase in catalase and reduced glutathione, and significant (p < 0.05) reduction in lipid peroxidation in treated mice. This study provides evidence for the seizure reducing property of creatine and its ameliorating potential on anxiety and depressive-like behaviors that follows seizure episodes.

Evaluation of some neuropharmacological effects of Caladium bicolor aiton (araceae) leaf extracts in mice.

Caladium bicolor Aiton (Araceae) is used in ethnomedicine for the treatment of boils, wound ulcers and convulsion. This study investigated the effects of the leaf extracts on some neuropharmacological parameters. The leaves were collected, dried, powdered and then extracted by maceration in methanol to yield the whole extract (WE). Extraction was also done using n-hexane, ethyl acetate and methanol in a Soxhlet apparatus to obtain n-hexane (HE), ethyl acetate (EA) and methanol (ME) extracts. Preliminary phytochemical screening was done using the whole extract. Some neuropharmacological evaluations were carried out using standard methods. Phytochemical screening revealed the presence of carbohydrates, proteins, alkaloids and flavonoids. WE showed varying levels of protection against strychnine-induced convulsion. Each of HE, EA and ME increased latency (P < 0.01) to pentylenetetrazole-induced convulsion and offered varying levels of protection against maximal electroshock-induced seizure. Each of WE, HE and ME significantly increased the duration of stay on the open arm of the elevated plus maze. Both EA and ME at doses of 100 and 200 mg/kg, and HE at a dose of 400 mg/kg significantly reduced the duration of immobility in forced swim test. It is concluded that the leaf extracts possess anticonvulsant, anxiolytic and antidepressant properties.