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 Feretia apodanthera on the course of kindling development, kindling-induced learning deficit, oxidative stress markers, and cholinesterase activity in pentylenetetrazole (PTZ)-kindled mice. Pentylenetetrazole, 30 mg/kg, induced kindling in mice after 30.00 +/- 1.67 days. The aqueous extract of Feretia apodanthera showed dose-dependent antiseizure effects. Feretia apodanthera (150-200 mg/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 Feretia apodanthera in a dose-dependent manner. The significant decrease in cholinesterase activity observed in the PTZ-kindled mice was reversed by pretreatment with the Feretia apodanthera extract. The results indicated that pretreatment with the aqueous extract of Feretia apodanthera antagonizes seizures, oxidative stress, and cognitive impairment in PTZ-kindled mice. The aqueous extract of Feretia 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 Feretia apodanthera as an adjuvant in epilepsy both to prevent seizures as well as to protect against seizure-induced oxidative stress and memory impairment. (C) 2014 Elsevier Inc. All rights reserved.