Chemical composition and larvicidal effects of essential oil of Blumea martiniana against Anopheles anthropophagus.

OBJECTIVE

To determine chemical composition of the hydrodistilled essential oil of Blumea martiniana, and to evaluate its larvicidal activity against Anopheles anthropophagus, the natural vector of malaria.

METHODS

Chemical composition of essential oils extracted by steam distillation was investigated by gas chromatography and mass spectroscopy (GC-MS). Larvicidal activity of essential oil and its four main compounds was carried out by WHO method. Twenty larvae of early fourth-instar stage were used in the larvicidal assay and five replicates were maintained for each concentration. The 24 h LC(50) and LC(90) values were determined following probit analysis.

RESULTS

Totally 68 compounds corresponding to 98.55% of the total oil were identified and the major constituents of essential oil were: linalool(10.36%), germacrene D(9.09%), borneol(6.24%), γ-terpinene(5.38%). The oil and linalool, germacrene D, borneol, γ-terpinene exerted significant larvicidal activity with LC(50) values of 46.86, 35.87, 44.61, 35.89, and 29.21 mg/L, respectively. It also showed a dose dependent effect on mortality.

CONCLUSIONS

The essential oil of Blumea martiniana and its four major compounds may have potential for use in control of Anopheles anthropophagus larvae and could be useful in search of newer, safer and more effective natural compounds as larvicides.