Repellent effect of the leaf extracts of Euphorbia Balsamifera (AIT) against Anopheles gambiae
The ethanol extract of the leaves of Euphorbia balsamifera (commonly known as Gwadayi in Hausa) was sequentially extracted with petroleum ether, chloroform, ethyl acetate and methanol. The resulting extracts were designated EB1, EB2, EB3, and EB4 respectively. The ethanol extract designated EB. These extracts were tested for repellence against Anopheles gambiae using the human-bait technique under laboratory conditions, where five volunteers participated in the tests, one each for the extracts. The chloroform extract labelled EB1-02 was found to be the most active with 100% repellence at 25% (w/v) concentration, and 97.2% at 12.5% (w/v) concentration, while the ethyl acetate extract (EB1-03) recorded the least repellence activity of 32.4% at 25% (w/v) concentration, and 21.6% at 12.5% (w/v) concentration. It can thus be concluded that the phytochemicals present in the chloroform extract were responsible for repellent activity of E. balsamifera, and there is a need for further studies in order to ascertain the active compound in the plant.
Keywords: Repellence, Anopheles gambiae, human-bait technique, Euphorbia balsamifera extracts.