Molluscicidal Potential of the Fruit Pericarp of Blighia unijugata Baker Against Biomphalaria pfeifferi

Blighia unijugata Baker (Sapindaceae) is a small to medium-sized tree up to 30m tall widespread in tropical Africa. The leaves are eaten as vegetable and various part of the tree are considered to have sedative and analgesic properties and are used in traditional medicine for the treatment of rheumatism, kidney pain and muscular stiffness.

The macerated twigs, leaves, flowers and fruit as a fish poison by the coastal people in Nigeria and there is a high correlation between plants employed as fish poison or soap substances and molluscicidal activity.

Powdered pericarp was macerated with 50% ethanol, filtered and the filtrate concentrated to dryness under vacuum to yield 10.30g of the dried extract and out of this 9.80g was dissolved in water and partitioned between ethyl acetate, butanol and water to give 2.77g of ethyl acetate, 2.81 of Butanol and 3.35 of water fractions respectively

Snails for the experiment were collected from streams that have not been subjected to either synthetic or plant molluscicides. They were allowed to acclimatize in the laboratory for two weeks before use.

The methods of Al-Zanbagi et al. (1) and Truiti et al. (2) were modified and used.

The crude ethanolic extract has LC₅₀ of 15ppm and for the fractions ethyl acetate was the most active with LC₅₀ of 7.6ppm while the butanol fraction had a LC₅₀ of 15 ppm and water fraction was the least active with LC₅₀ of 25ppm.

Efforts are being made to isolate the active compounds from each fraction.

Keywords: Blighia unijugata, fruit pericarp, crude extract, fractions, Biomphalaria pfeifferi

References: 1. Al-Zanbagii NA et al. (2000)J Ethnopharmacol 70:119–125

2. Truiti MCT et al. (2005) Braz J Med Biol Res 38: 1873–1878.