ANTIEPILEPTOGENIC AND MEMORY ENHANCING POTENTIALS OF METHANOL LEAF EXTRACT OF PARQUETINA NIGRESCENS (AFZEL) BULLOCK IN PENTYLENETETRAZOLE-KINDLED MICE

Abstract

Parquetina nigrescens is an important ethnomedicinal plant in Nigeria, use in the treatment of epilepsy and
enhancement of memory. The aim of the study is to evaluate the antiepileptogenic and memory enhancing potential
of methanol leaf extract of P. nigrescens. Antiepileptogenic and memory enhancing potentials were investigated in
mice following pentylenetetrazole (PTZ)-induced-kindling 48 hourly (35 mg/kg, i.p) and daily oral treatment with
the extract at doses of 250, 500 and 1000 mg/kg for a period of 22 days. Seizure behaviour was observed using the
Racine’s scale for 30 minutes after PTZ administration. On the 22nd day, 1 h after 11th PTZ injection; animals were
assessed for cognitive performance in Y-maze and elevated plus maze (EPM) and as well in EPM on day 23. The
extract at all doses and sodium valproate significantly (p<0.05) decreased seizure scores across treatment days. In
the EPM, the extract non-significantly decreased transfer latency on day 22 at all doses tested and significantly
(p<0.05) decreased transfer latency at 1000 mg/kg dose on day 23. Sodium valproate only significantly (p<0.05)
decreased transfer latency on day 22. In the Y-maze test, the extract only at 1000 mg/kg and sodium valproate
significantly (p<0.05) increased % spontaneous alternation and no significant increase in the number of arm entry
was observed with the extract. The methanol leaf extract of P. nigrescens possesses antiepileptogenic property and
improved learning and memory hence, may potentially improve epilepsy-related learning and memory impairment.