Molluscicidal Activity of Camellia Sinensis (Green Tea) and Camellia sinensis var. Assamica (Purple Tea) Extracts Against Biomphalaria pfeifferi, the Major Vector Snail of Human Schistosomiasis in Sub-Saharan Africa.

Freshwater pulmonate snails are prevalent across Kenya and act as intermediate hosts for trematode parasites, some of which are snail vectors for human schistosomiasis. Chemical molluscicides have rarely been used routinely in Kenya to control snails due to high costs of manufacture and the subsequent environmental concerns associated with their use. This study tested extracts from green tea and purple tea plants, Camellia sinensis, which are widely grown in Kenyan highland areas, against Biomphalaria pfeifferi, the obligate intermediate host for Schistosoma mansoni. Snails were exposed to five different concentrations of tea extracts (10, 20, 50, 100, and 150 ppm). All quantitative data analyses were done in R Version 4.4.0. Analysis by LCMS showed that the compounds present in the extracts were epicatechin, epigallocatechin, caffeine (the highest concentration of the compounds), theobromine, and assamsaponin C. The compounds identified by GCMS were hexadecanoic acid, caffeine, octadecenoic acid-methyl, and octadec-1-ene. The crude extracts from the Kenyan tea plant Camellia sinensis (both green and purple tea) induced mortality of the Biomphalaria pfeifferi. Therefore, they can be explored as alternative plant-based molluscicides against the vector snails of Schistosoma mansoni.