Screening and Larvicidal Activity of the Ethanol Root and Leaf Exract of Combretum molle Against Anopheles gambiae

Abstract

Mosquitoes are of public health importance as they constitute serious biting nuisance and transmit most deadly and life-threatening diseases. Plants have become the focus of intensestudy in terms of conservation and their pharmacological use. This study aimed at evaluating the larvicidal activity of stem extract of Combretum molle on Anopheles gambiae mosquito. The phytochemical analysis of the ethanol extract of the stem revealed the presence of biological active compounds including alkaloid, saponin, tannin, steroid and  flavonoid. The effect of theethanol extracts of the stem of Combretum molle (Bush willow) against the larvae of anopheles gambiae  mosquito was further investigated in accordance to the World Health Organization’sguidelines for laboratory and field testing of  mosquito larvicides (2005). Early second andthirdinstars larvae of anopheles gambiae mosquitoes were exposed for up to 48 Hours  to a concentration of 1, 25, 50 and 75ppm extracts of the roots and leaf. All tested extracts showed larval mortality, however, larval  mortality was greatest with the ethanol leaf extract at anincreasing concentration. This is supported by the abundance of flavonoid and  tannin compoundon the stem tissue. The study concluded that these parts of the Combretum molle contain larvicidal properties and could  be implore as a natural larvicidal agent.