Some neurological effects of the ethanolic stem bark extract of Cussonia bancoensis Aubrev and Pellgr (Araliaceae)

Abstract

In this study, some neurological effects of the 70% ethanolic stem bark extract (CB) of Cussonia bancoensis, Aubrev and Pellgr, (Araliaceae) were investigated in mice using various models. The effect of CB on the central nervous system (CNS) was studied using changes in general behavioural profiles (Irwin’s test), tail flick test, potentiation of pentobarbitone induced sleep and effect on convulsion threshold in mice. Administration of doses between 100 and 3000 mg/kg body weight showed marked reduction in spontaneous activity, decreased response to touch and pain, moderate loss of balance, presence of ptosis and sedation. There was no mortality recorded after 24 and 48 h of administration of a maximum dose of 3000 mg/kg body weight. The study has shown that the stem bark extract at doses between 300 and 3000 mg/kg body weight has a dose -dependent sedative effect. This was observed as a reduction of locomotor activity and marked potentiation of pentobarbitone induced sleep onset and duration in mice. The ethanolic extract of C. bancoensis (CB) also significantly increased latency to tail withdrawal at 54 ±1 oC in a dose dependent manner. Effect of CB extract on the onset and duration of pentylenetetrazole (PTZ) induced seizures was however insignificant. Based on these results, the traditional use of C. bancoensis in the management of pain and its ability to induce dizziness and sedation are justified. This observation may be attributed to the presence of plant secondary metabolites such as saponins and tripterpenoids which tested positive in the preliminary phytochemical screening of the powdered stem bark.