Studies on the molluscicidal and larvicidal properties of Solanum nigrum L. leaves ethanol extract.

Toxicological studies on three ethanol extract preparations of Solanum nigrum L. leaves were made on Biomphalaria alexandrina. Extract (A), made by soaking leaves powder over night in cold 70% ethanol, has the highest activity, (LC50 3.37 mg/L within 24 hr). This extract also showed larvicidal activity against larvae of two mosquito species, Aedes caspius and Culex pipiens, (LC50 51.29 and 125.89 mg/L within 24 hr, and 21.38 and 38.11 mg/L within 48 hr, respectively). Sunlight, pH, and turbidity did not affect the activity of this extract, but the molluscicidal activity seems to be correlated with the increase of temperature. The concentrated extract (1000 mg/L) can be stored at room temperature for six months without any change in its activity, but diluted solutions of this extract lost their activity after four weeks.