Larvicidal activity and GC-MS analysis of Piper longum L. leaf extract fraction against human vector mosquitoes (Diptera: Culicidae)

Abstract

Mosquitoes are the vectors for transmitting major public health diseases like dengue, filariasis, and malaria. Among the various mosquito larval control agents, plant extracts and isolated phytocompounds are good alternatives to control vector mosquitoes. The objective of this study is to test the efficacy of leaf extract fraction prepared from the locally available plant, Piper longum L in decimating the larvae of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. Piper longum leaf extract fraction was isolated through column chromatographic separation and phytochemical analysis was carried out by standard procedures. The larvicidal assay was carried out following WHO methods, and the P. longum fraction was tested at various concentrations (10-80µg/dl) on the third instar larvae of Ae. aegypti, An. stephensi, and Cx. quinquefasciatus. The 24h LC50, LC90 values were as determined using probit analysis. GC-MS analysis was done for the identification of bio-active compounds present in the specific P. longum leaf fraction. The fraction of P. longum leaf extract contains secondary metabolites such as alkaloids, glycosides, saponins, phytosterols, diterpenes, triterpenes, phenols, tannins, steroids, and terpenoids. The LC50 and LC90 values were 38.96 and 41.53; 45.06, and 71.16; 72.02 and 76.80 µg/dl against Ae. Aegypti, An. stephensi, and, Cx. quinquefasciatus respectively. Twenty-nine phytocompounds were identified by GC-MS. The present results suggested that the fraction of P. longum leaf extract checked for mosquito larvicidal activity had an excellent potential for controlling selected human vector mosquitoes.