Phytochemical Screening and Evaluation of the Larvicidal Activities of Three Organic Extracts Derived from the Leaves of Cassia sieberiana to Control Anopheles gambiae, the Vector of Malaria

Abstract

Senegal is one of the African countries where malaria remains a major public health problem. In the fight against mosquitoes, the vector of this disease, the significant accumulation of active ingredients in ecosystems treated with synthetic insecticides poses an increased environmental problem linked to the very high persistence time. The aim of this study is to propose an alternative method of vector control using natural products of plant origin. Three organic extracts (cyclohexanic, chloroformic and methanolic) from the leaves of Cassia sieberiana were tested by contact on mosquito larvae of the genus Anopheles gambiae. Four doses of each extract were prepared and monitored over 48 hours. The families of chemical compounds in the various organic extracts are identified using coloring and precipitation tests. The results obtained show a variable sensitivity of the larvae, reflected in low to very high mortality rates when moving from one extract to another. The chloroform extract was the most effective, with a mortality rate of just under 90% after 48 hours' exposure. Phytochemical screening reveals that this plant is rich in secondary metabolites such as polyphenols and alkaloids, which could explain its larvicidal activity.