Anticonvulsant activity of the aqueous extract of Allium cepa L. (Amaryllidaceae) in rats and mice

Abstract

The aqueous extract of Allium cepa (ACE) has been reported to be  effective in the treatment of convulsion. We therefore investigated its effect on seizures induced by maximal electroshock stimulation (MES) and
pentylenetetrazole (PTZ) in rats and mice. The preliminary phytochemical constituents were also elucidated. The extract contained tannins,  flavonoids, cardiac glycosides, reducing sugars, saponins and alkaloids. Anthraquinones, steroids and terpenes were absent. In the electrically-induced seizure, ACE significantly (p< 0.01) prolonged the onset of tonic convulsion at all doses. It also reduced the duration of the tonic convulsion at all doses but it is only significant at 50mg/kg (p< 0.02), 200mg/kg (p< 0.03) and 400mg/kg (p< 0.004). It was reduced from 3.295 ± 0.448s (control) to 1.172 ± 0.837s (50mg/kg); 1.62 ± 0.670s (200mg/kg) and 0.832 ± 0.376s (400mg/kg). In the PTZinduced seizure ACE prolonged the onset of tonic convulsion at 50mg/kg and 200mg/kg dose but it was
insignificant. It was increased from 3.469 ± 1.335 min (control) to 3. 999 ± 1.658 min (50mg/kg) and 4.261 ± 0.740 min (200mg/kg). It also delayed the time it took for the mice to die at 50mg/kg and 200mg/kg, although not significantly. It is concluded that Allium cepa extract has an  anticonvulsant effect especially in MES-induced seizure and could serve as a good alternative for the treatment of convulsion. This observation  explains, at least in part, the basis for its use by herbalists for the treatment of convulsion.

Keywords: Maximal electroshock stimulation; Pentylenetetrazole;  Anticonvulsant; Allium cepa