Molluscicidal Activity of Aqueous Methanol and Hexane Fractions of Tetrapleura tetraptera Stem Bark against Biomphalaria pfeifferi

Snail infections and parasitic diseases associated with snails such as schistosomiasis remain a problem in some endemic communities in Nigeria. Consequently, effective molluscicides are needed to control these parasites. However, frequent use of commercially available molluscicides may cause unnecessary environmental pollution. This necessitates the advocacy for natural alternatives to commercially available synthetic molluscicides. This study aimed to investigate the molluscicidal activity of aqueous methanol and hexane fractions of Tetrapleura tetraptera stembark against Biomphalaria pfeifferi snails. A total of two hundred and eighty (280) mature snails from Giri River, Gwagwalada Area Council of the Federal Capital Territory (FCT), Abuja, Nigeria, were subjected to immersion bioassay with methanol and hexane fractions of Tetrapleura tetraptera stembark. Dechlorinated water was used as negative control while CuSO4.5H2O (aq) was employed as positive control. Treatment concentration ranged from 0.39 mg/L to 12.5 mg/L and snail death was measured at 24, 48, and 72 hours post-exposure. The results revealed that the aqueous methanol fraction of Tetrapleura tetraptera stembark have high molluscicidal activity with LC90 of 2.184 ± 0.61 mg/L and LC50 of 0.647± 0.61 mg/: after 24 hours exposure time; while the hexane extract showed no significant toxicity towards the test organism. This observation may be attributed to the presence of tannins glycosides or carbohydrates prominent in the aqueous methanol fraction and were not present in the hexane fraction. Findings from this study provide considerable basis for further exploiting the aqueous methanol fraction of Tetrapleura tetraptera stembark and local indigenous plants for as potential molluscicidal agents.