Chemical Composition of Citronella (Cymbopogon winterianus) Leaves Essential Oil and Gastric Toxicity of Its Major Components to Drosophila melanogaster Larvae

Abstract

Cymbopogon winterianus is an aromatic plant of Poaceae that has many biological activities, including insecticidal, bacteriostatic, and anti-inflammatory activities. It is widely used in the food, medicine, and cosmetics industries. The aim of this study was to investigate the gastric toxicity of citronella essential oil and its main component, geraniol, to Drosophila melanogaster larvae. C. winterianus was produced in Dongxing City (Guangxi Province, China), and its essential oil was obtained by steam distillation. The chemical composition of citronella essential oil was analyzed using gas chromatography-mass spectrometry (GC-MS). The gastric toxicity of citronella essential oil and its main components against the second-instar larvae of D. melanogaster was studied. The GC-MS analysis identified 63 volatile components, of which 19 chemical constituents had a relative content of more than 0.50% each in the citronella essential oil, accounting for 92.89% of the total essential oil. The constituents mainly include geraniol (18.88%), citronellal (16.95%), elemenol (14.08%), and citronellol (12.57%). These results are different from the reported results in terms of species and content. The underlying reasons for the differences could be attributed to the variety, production area, and harvest time. The results of gastric toxicity showed that the LC50 values of citronella essential oil and geraniol were 40.06-48.51 and 7.82-10.42 μL/mL, respectively, in treated D. melanogaster larvae. The geraniol showed good gastric toxicity, and the corrected mortality was 100% at 20.00 μL/mL when D. melanogaster larvae were treated for 24 h. Both citronella oil and geraniol showed gastric toxicity to D. melanogaster larvae, but the gastric toxicity of geraniol was significantly higher than that of citronella oil. Thus, geraniol, from citronella (C. winterianus) essential oil, may have value for control of D. melanogaster and may be developed into a plant-derived insecticide.