Phytochemical screening and larvicidal efficacy of methanolic extracts of folklore medicinal plants against Aedes aegypti (Diptera: Culicidae)Author(s): A.Chinmaya, S.J.Sudharshan, T.R.Prashith Kekuda, S.V.Praveen Kumar, N.C.Valleesha, Syed Murthuza
In this study, we investigated the larvicidal activity of the methanolic extracts from traditionally used medicinal plants namely Putranjiva roxburghii Wall., Coscinium fenestratum Colebr, and Nardostachys jatamansi DC against larvae of Aedes aegypti. The larvae were taken in beakers were exposed to methanolic extracts of the plants at concentrations of 1, 2.5 and 5mg/ml for 24hours followed by counting of dead larvae and percentage mortality was calculated. The LC50 was also determined for each extract.All extracts showed larval mortality. Larval mortality was 100%with the use of 2.5 and 5%concentration of extract of each plant. The LC50 for N. jatamansi, P. roxburghii and C.fenestratum was found to be 0.83mg/ml, 0.90mg/ml and 1.25mg/ml respectively suggestingN. jatamansi is more potent followed by P. roxburghii and C. fenestratum. Qualitative analysis of the extracts revealed the presence of tannin, alkaloid, steroid and flavonoid in all the extracts. Saponin was not detected in N. jatamansi, while terpenoid was not detected in all the extracts. The larvicidal activity could be mainly due to the presence of phytoconstituents in the methanol extract. It is suggested that all the three plants possess larvicidal properties and could be used as natural insecticides for mosquito control.