Evaluation of the anticonvulsant, hypnotic and anxiolytic-like effects of methanol seed extract of Dennettia tripetala in mice

Abstract

Background: Epilepsy is a chronic neurological disease characterized by recurrent seizure together with sleep disorder and anxiety. Current drugs used in the management of this disease conditionare associated with serious side effects, relapse and ineffectiveness in wide population necessitating the search for alternative therapy. The fruit of Dennettia tripetala (DT) is widely used for its various health-promoting effects including relief of seizures, insomnia and anxiety in ethno-medicine. Hence, this study investigated the effects of methanol seed extract of DT on convulsion, hypnosis and anxiety in mice.

Methods: Convulsion was induced with intraperitoneal injection of pentylenetetrazole (PTZ) (80 mg/kg) 60min after oral pretreatment of mice with DT (61.25, 122.5 and 245 mg/kg), diazepam (2 mg/kg) or distilled water (10 mL/kg). The animals were then observed for 30min for the occurrence of seizure. Interaction study with flumazenil on the anticonvulsant effect of DT was assessed. The effects of DT (61.25, 122.5 and 245 mg/kg, p.o.) on hypnosis and anxiety were also evaluated using pentobarbital-induced hypnosis and elevated-plus maze tests in naïve mice.

Results: DT (61.25, 122.5 and 245 mg/kg) significantly prevented PTZ-induced convulsion relative to control; however, flumazenil reduced the anticonvulsant effect of DT. Pretreatment with DT produced anxiolytic-like effect in naïve mice, reduced sleep-latency and enhanced total-sleeping time in pentobarbitone-treated mice.

Conclusions: The results of this study suggest that the seed extract of Dennettia tripetala possesses anticonvulsant, hypnotic and anxiolytic-like properties. The positive effects of DT may be related to central enhancement of GABAergic activity.

Keywords: Dennettia tripetala; Seizure;Chemocovulsants; Anxiety-related disorders;Hypnosis; GABA; Antiepileptics; Anxiolytics