Anticonvulsant activity of Hedranthera barteri

Hedranthera barteri (Hook.f.) Pichon (Apocynaceae) is used traditionally in the treatment of convulsion in Southern Nigeria.

The anticonvulsant activity of the methanol extract of H. barteri leaves was investigated.

The anticonvulsant activity of the extract (50,100 and 200 mg/kg, p.o.) was investigated in seizures induced by picrotoxin and strychnine in mice. The total phenol and flavonoid contents were determined using a modified colorimetric method and the aluminium chloride method, respectively. The mineral composition of the plant was analyzed using atomic absorption spectrophotometry.

The extract significantly prolonged the onset and reduced the duration of the seizures induced by picrotoxin (5 mg/kg, i.p.) and strychnine (1 mg/kg, i.p.). The response was, however, not dose-dependent. Phenobarbitone (2 mg/kg) completely protected the animals from seizures while diazepam (1 mg/kg) only prolonged the onset and reduced the duration of the seizures. The total phenol and flavonoid contents were 236.81 ± 0.05 mg gallic acid equivalent/g dry weight and 51.45 ± 0.01 mg quercetin equivalent/g dry weight, respectively. The elemental analysis revealed the presence of calcium 102.87 mg/g, magnesium 63.29 mg/mg, iron 54.16 mg/g, potassium 54 mg/g, sodium 48.95 mg/g, zinc 46.70 mg/g, manganese 41.72 mg/g, and copper 18.29 mg/g.

The results suggest that the methanol extract of H. barteri has anticonvulsant activity and may be exerting its effect by affecting the gabaergic and glycinergic mechanisms. The observed activity may be due to its flavonoid content and the appreciable amount of calcium present in the plant.