Standardization and evaluation of anticonvulsant activities of leaf extract and fractions of Waltheria indica (Baudilio) (Malvaceae)

Abstract

This study evaluated the anticonvulsant property of Waltheria indica leaf extract and fractions. Waltheria indica leaves were harvested, identified with herbarium specimen deposited, air-dried and pulverized. The pulverized leaves were soxhlet extracted using aqueous methanol. The crude extract was dried in vacuo. Phytochemical, pharmacognostic standards and toxicity evaluations were carried out. The crude extract was screened for anticonvulsant activity at concentrations of 250mgkg-1 and 500mgkg-1 ; and subsequently subjected to liquid- liquid partitioning with n-hexane, chloroform, n-butanol, methanol and water, to obtain the respective fractions. These fractions were screened for anticonvulsant activity. The most active fraction was subjected to vacuum liquid chromatography (VLC) and the VLC fractions screened using analytical HPLC. The leaf contains saponins (7.2%), alkaloids (10.2%) and flavonoids (6.8%); while proximate analysis showed moisture content of (15.83%), total ash (6%) and acid insoluble ash (5%). The LD50 was > 5000mgkg-1. Anticonvulsant evaluations showed that at 250mgkg-1 chloroform showed protection of (80%), crude extract (40%), methanol fraction (40%), n-hexane (20%)
and n-butanol (20%). At 500mgkg-1 chloroform fraction showed protection of (100%), crude extract (60%), methanol (60%), n-butanol fractions (60%) and n-hexane (40%). The HPLC screening identified phyto-compounds
with reported anticonvulsant activity (Astragalin, p-Hydroxybenzoic acid, (z)-Oct-2-ene-1, 3, 8-tricarboxylic acid, (z)-2-(7-hydroxyoctyl) pent-2-enedioic acid and Septicine). Waltheria indica leaf extract is non-toxic and
significantly delayed the onset of convulsion and onset of death due to convulsion and reduced the number of convulsion per minutes. The protections given were dose dependent. This study established anticonvulsant property of Waltheria indica leaf, thus supports its ethnomedicinal use.
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