A Comparative Study on the Larvicidal Effects of Piper sarmentosum (Kaduk) Leaves Extracts against Aedes aegypti

Abstract

Excessive use of synthetic larvicide has led to resistant strains of mosquito vectors and adverse ecological concerns globally. Hence, bioactive compounds from the plant have become a promising alternative to synthetic larvicide. Collectively, there is adequate evidence on the larvicidal effect of Piper sarmentosum (Kaduk). However, its leaves extract’s larvicidal effects in different solvent systems are still recondite against Aedes aegypti. The present study aims to investigate the larvicidal activity of the leaves extracts of P. sarmentosum in methanol (ME), ethyl acetate (EE), dichloromethane (DE) and hexane (HE), towards the larvae of A. aegypti, following the laboratory guidelines provided by the World Health Organization (WHO). HE shows a significantly highest larvicidal activity followed by DE, EE and ME, with LC50 and LC90 values of 39.04 and 87.84, 62.78 and 134.73, 114.70 and 169.20, 156.10 and 182.10 μg/mL, respectively. The HE was also found to contain the highest total phenolic and total flavonoid content (TPC and TFC), with various bioactive compounds at a higher percentage that exerts synergistic effects on the significantly improved larvicidal effect of HE compared to other solvent extracts. The morphological observation of A. aegypti larvae upon exposure to HE revealed a significant shrinkage of the internal structure of abdominal and siphon segments that indicates the acute toxicity effect of HE. The present study provides scientific-based evidence on the strongest larvicidal effect of HE from P. sarmentosum leaves extract towards A. aegypti for further development as a potential alternative for synthetic larvicide.