The molluscicidal effects of extracts of <em>Capsicum annuum</em> (Sweet pepper), <em>Ocimum Basilicum</em> (Scent leaf) and <em>Piper nigrum</em> (Black pepper) on fresh water snails

Abstract

Extracts of sweet pepper (Capsicum annum), black pepper (Piper nigrum) and scent leaves (Ocimum basilicum) were introduced to fresh water snail samples, the intermediate hosts of schistosomiasis, to test their molluscicidal effects. The materials were extracted using soxhlet extraction. Black pepper (Piper nigrum) was found to be most toxic of the three on the species of the fresh water snails. A mixture of sweet pepper (Capsicum annum) and black pepper (Piper nigrum) extracts was highly toxic on the snails (Onchomelina spp. and Bulinus spp.), and killed the snails instantly on contact. This shows that the combinations of sweet pepper and black pepper extracts were synergistic in their toxicity when compared with the other extracts on the snail species (Onchomelina spp. and Bulinus spp.). The extracts and their combinations are therefore recommended for use as molluscicides in controlling the intermediate hosts (Onchomelina and Bulinus spp.) of schistosomiasis as against the use of chemicals that are poisonous to humans, aquatic animals and the entire ecosystem.