Mosquito repellent activity of the leaf extracts of Lawsonia inermis (l)
The ethanolic extract of the leaves of Lawsonia inermis (commonly known as lalle in Hausa) was sequentially extracted with petroleum ether, chloroform, ethyl acetate and methanol. The extracts were respectively labeled LI1, LI2, LI3, and LI4, with the ethanolic extract labeled LI, and 12.5% and 25% of the test extracts were tested for repellency against Anopheles gambiae, and the repellent activity was assessed using the human-bait technique. Five volunteers participated in the laboratory tests, one each for the extracts. The chloroform extract labeled LI1-02 was found to be the most active, (100% repellency), while the extract labeled LI1-03 (25%) recorded the least activity (15.4%). It can be concluded that the chloroform extract labeled LI1-02 is responsible for repellent activity of Lawsonia inermis.
Keywords: Repellency, Anopheles gambiae, human-bait technique, Lawsonia inermis extracts.