Extracts of Feretia apodanthera Del. demonstrated anticonvulsant activities against seizures induced by chemicals and maximal electroshock.

Extracts of Feretia apodanthera Del. (Rubiaceae) have been extensively used in traditional Cameroonian medicine to treat a variety of diseases, including some neurological disorders. The present study was aimed to tests the anticonvulsant properties of the aqueous extract and the alkaloid fraction of the stem barks of Feretia apodanthera. The anticonvulsant investigation was carried out against bicuculline-, picrotoxin-, pentylenetetrazol-, Methyl-ß-carboline-3-carboxylate-, N-Methyl-D-aspartate-, 4-aminopyridine-, and maximal electroshock-induced seizures or turning behavior in mice. The aqueous extract protected mice against bicuculline-, picrotoxin-, pentylenetetrazol-, Methyl-ß-carboline-3-carboxylate-, N-methyl-D-aspartate -, 4-aminopyridine- and maximal electroshock-induced seizures or turning behavior. Also, N-Methyl-D-aspartate-, 4-aminopyridine- and maximal electroshock- induced seizures or turning behavior, were significantly antagonized by the alkaloid fraction (80mg/kg) from Feretia apodanthera. The total protection of mice provided by the aqueous extract against convulsions induced by pentylenetetrazol or picrotoxin was anagonized by flumazenil, a specific antagonist of the benzodiazepine site in the GABAA receptor complex. The aqueous extract of Feretia apodanthera (but not the alkaloid fraction) increased the brain GABA content and inhibited the GABA transaminase activity. In conclusion, Feretia apodanthera was revealed possessing anticonvulsant effects in mice, likely via the GABAergic neurotransmission.

Effects of a lyophilized aqueous extract of Feretia apodanthera Del. (Rubiaceae) on pentylenetetrazole-induced kindling, oxidative stress, and cognitive impairment in mice.

Feretia apodanthera Del. (Rubiaceae) is extensively used in ethnomedicine in Cameroon and Nigeria for epilepsy, febrile convulsions, and rheumatic pains and for enhancing cognitive performance. The aim of the present study was to examine the effects of a lyophilized aqueous extract of F. apodanthera on the course of kindling development, kindling-induced learning deficit, oxidative stress markers, and cholinesterase activity in pentylenetetrazole (PTZ)-kindled mice. Pentylenetetrazole, 30mg/kg, induced kindling in mice after 30.00±1.67days. The aqueous extract of F. apodanthera showed dose-dependent antiseizure effects. Feretia apodanthera (150-200mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures, and generalized tonic-clonic seizures. The extract also improved the seizure score and decreased the number of myoclonic jerks. Pentylenetetrazole kindling induced significant oxidative stress and cognitive impairment which were reversed by pretreatment with F. apodanthera in a dose-dependent manner. The significant decrease in cholinesterase activity observed in the PTZ-kindled mice was reversed by pretreatment with the F. apodanthera extract. The results indicated that pretreatment with the aqueous extract of F. apodanthera antagonizes seizures, oxidative stress, and cognitive impairment in PTZ-kindled mice. The aqueous extract of F. apodanthera also showed anxiolytic activities, but the inhibition of memory impairment was not attributed to the anxiolytic activities of the plant. These results thus suggest the potential of F. apodanthera as an adjuvant in epilepsy both to prevent seizures as well as to protect against seizure-induced oxidative stress and memory impairment.

The anticonvulsant and sedative effects of Gladiolus dalenii extracts in mice.

Gladiolus dalenii Van Geel is a medicinal plant commonly used in traditional medicine in Africa to treat epilepsy and many other diseases. Two in vivo mouse models (maximal electroshock and pentylenetetrazol-induced convulsions) were used to evaluate the anticonvulsant activities of the plant extracts. Diazepam-induced sleep was used for the evaluation of the sedative properties. The macerated extract of G. dalenii protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The aqueous extract of G. dalenii protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The lyophilized extract of G. dalenii also protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The coadministration of G. dalenii with diazepam resulted in an additive effect, while the coadministration of G. dalenii with flumazenil or FG7142 resulted in antagonistic effects. The macerate of G. dalenii also exerted sedative activity by reducing the latency time to sleep and increasing the total duration of sleep induced by diazepam. The sleeping time increased from 16±3min in the control group to 118±11min at a dose of 150mg/kg of G. dalenii. The effects of G. dalenii suggested the presence of anticonvulsant and sedative activities that might show efficacy against secondarily generalized tonic-clonic seizures and primary generalized seizures and insomnia in humans.

Decoctions of Bridelia micrantha and Croton macrostachyus may have anticonvulsant and sedative effects.

Bridelia micrantha and Croton macrostachyus are medicinal plants used empirically in traditional medicine to treat epilepsy. In vivo mice model (maximal electroshock, strychnine, pentylenetetrazol, picrotoxin, isonicotinic hydrazide acid)-induced convulsions were used to evaluate the anticonvulsant activities of those plants. Diazepam-induced sleep was used for the evaluation of the sedative properties. B. micrantha protected 100, 80, 80, and 80% of mice against PIC, STR, PTZ and MES-induced seizures, respectively. C. macrostachyus at the doses 34 and 67 mg/kg protected 80, 80, 80 and 60% of mice from PIC, STR, PTZ and MES-induced seizures, respectively. B. micrantha and C. macrostachyus also delayed the onset to seizures in INH test. B. micrantha was more potent than C. macrostachyus in protecting mice against convulsions. The co-administration of the sub effective dose of the decoction of B. micrantha or C. macrostachyus with the sub effective dose of diazepam or clonazepam resulted in a synergistic effect. The decoctions of B. micrantha and C. macrostachyus also exerted sedative activity by increasing the total duration of sleep induced by diazepam and by reducing the latency time to sleep. The effect of the decoctions of B. micrantha and C. macrostachyus suggests the presence of anticonvulsant activities that might show efficacy against secondarily generalized tonic-clonic seizures and primary generalized seizures in humans.

Anticonvulsant, anxiolytic, and sedative properties of the roots of Nauclea latifolia Smith in mice.

Root bark of Nauclea latifolia Smith (Rubiaceae) was evaluated for its anticonvulsant, anxiolytic, and sedative activity in mice. Animal models (maximal electroshock-, pentylenetetrazol-, and strychnine-induced convulsions; N-methyl-D-aspartate-induced turning behavior; elevated plus maze; stress-induced hyperthermia; open field; and diazepam-induced sleep) were used. The decoction from the bark of the roots of N. latifolia strongly increased the total sleep time induced by diazepam. It also protected mice against maximal electroshock-, pentylenetetrazol-, and strychnine-induced seizures. In addition, turning behavior induced by N-methyl-D-aspartate was inhibited. N. latifolia antagonized, in a dose-dependent manner, stress-induced hyperthermia and reduced body temperature. In the elevated plus maze, N. latifolia increased the number of entries into, percentage of entries into, and percentage of time in open arms, and reduced rearing, head dipping, and percentage of time in closed arms. In the open field test, N. latifolia increased crossing and reduced rearing and defecation. It could be concluded that the decoction of N. latifolia, used in traditional medicine in Cameroon in the treatment of fever, malaria, insomnia, anxiety and epilepsy seemed to possess, sedative, anticonvulsant, anxiolytic and antipyretic properties in mice.

The anticonvulsant and sedative properties of stems of Cissus quadrangularis in mice

Cissus quadrangularis Linn grows in Savannah areas in Africa (Cameroon; Mali; Mauritania; Senegal; etc). In traditional medicine; the plant is used to treat anorexia; asthma; sickle cells; colds; pains; malaria; asthma and as an analgesic. In vivo animal models of epilepsy (maximal electroshock; n-methyl -d-aspartate; pentylenetetrazol; isonicotinic hydrazid acid and strychnine -induced convulsions or turning behavior) and insomnia (diazepam -induced sleep) were used. The aqueous extract of the stems of C. quadrangularis strongly increased the total sleep time induced by diazepam (50 mg/kg i.p.). It also protected mice against maximal electroshock; pentylenetetrazol; strychnine and n-methyl-d-aspartate-induced seizures or turning behavior and delayed the onset time of seizures induced by isonicotinic hydrazid acid. The results lead to the conclusion that the extract of C. quadrangularis possesses anticonvulsant and sedative properties in mice and could explain its use in traditional medicine in Africa; in the treatment of insomnia and epilepsy

Anticonvulsant activity of Mimosa pudica decoction.

The decoction of Mimosa pudica leaves given intraperitoneally at dose of 1000-4000 mg/kg protected mice against pentylentetrazol and strychnine-induced seizures. M. pudica had no effect against picrotoxin-induced seizures It also antagonized N-methyl-D-aspartate- induced turning behavior. These properties could explain its use in African traditional medicine.

Effects of Cyperus articulatus compared to effects of anticonvulsant compounds on the cortical wedge.

Cyperus articulatus L. (Cyperaceae) is a plant commonly used in traditional medicine in Africa and Latin America to treat many diseases. The water extract from rhizomes of Cyperus articulatus concentration-dependently reduced spontaneous epileptiform discharges and NMDA-induced depolarisations in the rat cortical wedge preparation at concentrations at which AMPA-induced depolarisations are not affected. The two antiepileptic compounds, valproate and ethosuximide, possessed effect neither on epileptiform discharges nor on AMPA- and NMDA-induced depolarisations. Phenobarbital, pentobarbital and phenythoin inhibited both AMPA- and NMDA-induced depolarisations and spontaneous epileptiform discharges. The effects of Cyperus articulatus were very close to the effect of D-CPPene. D-CPPene also inhibited spontaneous epileptiform discharges and antagonised NMDA- but not AMPA-induced depolarisations. The extract of Cyperus articulatus could contain components acting as NMDA antagonists.