The molluscicidal effect of the bark of “Bitza” tree (albizia coriaria): A local discovery towards the control of schistosomiasis in the Abay River Valley of Western Ethiopia

Abstract

Abstract: The extract of the bark of a tree locally known as "Bitza" (Albizia coriaria) is traditionally used for fishing by the indigenous population of the western part of the Abay (Blue Nile) River Valley of Ethiopia. The same bark was found to have molluscicdal effect. Laboratory tests showed that 100% of Biomphalaria snails die at 50ppm and above when exposed to the water, ethanol or methanol extract of the bark for six hours. Chemical analysis of the extract showed the active ingredients to be tannins which are known to have less active molluscicidal properties than saponins. Although Albizia coriaria is not recommended for a largescale use as a molluscicide because of its low potency compared to Endod (Phytolacca dodecandra), the discovery demonstrates how local traditional wisdom may form a starting point in the scientific search for other plant molluscicides. [Ethiop. J. Health Dev. 1997;11(1):89-92]