Composition and immunotoxicity activity of essential oils from leaves of Zingiber officinale Roscoe against Aedes aegypti L.

The leaves of Zingiber officinale Roscoe were extracted and the major essential oil composition and immunotoxicity effects were studied. The analyses were conducted by gas chromatography and mass spectroscopy (GC-MS) revealed that the essential oils of Z. officinale leaves. The Z. officinale essential oil yield was 0.26%, and GC/MS analysis revealed that its major constituents were Camphene (5.26%), Phellandrene (6.58%), Zingiberene (36.48%), Geranial (4.32%), β-gurjunene (2.74%), and Citronellol β-sesguiphellandrene (12.31%). The essential oil had a significant toxic effect against early fourth-stage larvae of Aedes aegypti L with an LC(50) value of 46.38 ppm and an LC(90) value of 84.32 ppm. Also, Camphene (≥95.0%), Phellandrene (≥95.0%), Zingiberene (≥95.0%), Geranial (≥95.0%), β-gurjunene (≥97.0%), and Citronellol (≥95.0%) were tested against the F21 laboratory strain of A. aegypti. Zingiberene (≥95.0%) and Citronellol (≥95.0%) have medium activity with an LC(50) value of 99.55 ppm and 141.45 ppm. This indicates that other major compounds may play a more important role in the toxicity of essential oil.