Aedes aegypti larvicide from the ethanolic extract of Piper nigrum black peppercorns

Abstract

Due to unavailability of a vaccine and a specific cure to dengue, the focus nowadays is to develop an effective vector control method against the female Aedes aegypti mosquito. This study aims to determine the larvicidal fractions from Piper nigrum ethanolic extracts (PnPcmE) and to elucidate the identity of the bioactive compounds that comprise these larvicidal fractions. Larvicidal assay was performed by subjecting 3rd to 4th A. aegypti instar larvae to PnPcmE of P. nigrum. The PnPcmE exhibited potential larvicidal activity having an LC₅₀ of 7.1246 ± 0.1304 ppm (mean ± Std error). Normal phase vacuum liquid chromatography of the PnPcmE was employed which resulted in five fractions, two of which showed larvicidal activity. The most active of the PnPcmE fractions is PnPcmE-1A, with an LC₅₀ and LC₉₀ of 1.7101 ± 0.0491 ppm and 3.7078 ppm, respectively. Subsequent purification of PnPcmE-1A allowed the identification of the larvicidal compound as oleic acid.

Keywords::

• Aedes aegypti
• Piper nigrum
• larvicidal
• dengue

Acknowledgements

The authors wish to thank the Center for Biopharmaceutical Research and the Department of Parasitology & Microbiology at the De La Salle Health Sciences Institute for the larvicidal bioassay and UP Diliman NMR Facility for the spectral data.

Additional information

Funding

This work was supported by the Philippine Council for Health Research and Development – Department of Science and Technology (PCHRD-DOST) [grant number FP 110004].