The effects of natural products from a medicinal plant (Cinnamosma fragrans) on contractions of a visceral muscle in the Zika vector Aedes aegypti

Abstract

Mosquito‐borne diseases such as malaria, dengue fever, and Zika, are a constantly evolving problem with newly emerging and reemerging pathogens threatening the health of millions of individuals worldwide. Prevention of these diseases relies on the effective control of mosquito populations with insecticides. Our group is developing new insecticides derived from natural products of the Madagascan medicinal plant Cinnamosma fragrans by understanding the interactions of these compounds with mosquitoes on a molecular and physiological level and how they exert their toxic effects. The goal of this study is to determine the effects of natural drimane sesquiterpene compounds isolated from the medicinal plant C. fragrans on the visceral muscle contractions of the ventral diverticulum (crop) in adult female yellow fever mosquitoes (Aedes aegypti), an important vector of Zika virus. Using an established bioassay, we evaluated the acute effects of several drimane sesquiterpenes on contraction rates of isolated crops in Ringer solution. Our results demonstrate that at least two insecticidal drimane sesquiterpenes significantly inhibit the spontaneous and serotonin‐stimulated contractions of the crop. The potency of their inhibition correlates with their potency as insecticides, suggesting that visceral muscle inhibition may be responsible for the toxic effects of the compounds on mosquitoes. Moreover, parallel experiments in the crop with a calcium ionophore (A23187) duplicate the effects of the natural compounds, suggesting that they may elicit muscle inhibition by modulating calcium permeability of the crop muscle cells. Future research will investigate the presence and roles of calcium channels within the crop, attempting to better understand their interaction with C. fragrans natural compounds.Support or Funding InformationSupported by NIH grant R21AI129951.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.