Schinus terebinthifolius essential oil and fractions in the control of Aedes aegypti

Abstract

Several technologies have been developed to control Aedes aegypti, mainly studies on isolated plant molecules. The Schinus terebinthifolius (Raddi) (Anacardiaceae), popularly known as pink pepper is a plant widely used in reforestation of degraded areas and its fruits are used as condiments. The objective of this work was to investigate the potential of essential oils (EOs) and fractions (FRs) obtained from fresh fruits and leaves of S. terebinthifolius. The EOs were obtained by hydrodistillation (2 hours), fractionated on a chromatographic column using as the stationary phase silica gel 60 (0.063-0.2mm), mobile phases: n-hexane, dichloromethane, ethyl acetate and methanol and chemically evaluated by gas chromatography coupled to mass spectrometer (GC/MS). EOs and FRs were tested against larvae of the third stage and pupae of  Ae. aegypti by Immersion Test at concentrations ranging from 500.00 to 0.003 mg mL^-1 (v/v). The hexane FRs obtained from fruits and leaves were the ones that showed the greatest activity on the larvae (LC_99.9= 0.60 mg mL^-1 and LC_99.9 0.64 mg mL^-1, respectively) and pupae (LC_99,9 = 2.51 mg mL^-1 and 2.61 mg mL^-1, respectively). These results were confirmed by the anticholinesterase activity where the hexane (fruit and leaf) FRs presented the highest inhibitory potential on the acetylcholinesterase enzyme (0.156 mg mL^-1 and 0.312 mg mL^-1, respectively), suggesting the likely mechanism of action. The larvicidal potential can be explained by the presence of the major compounds bicyclogermacrene and germacrene D in the hexane FRs, indicating in this way that they may replace or even act in synergisms with conventional chemical larvicides. In this way the present study opens the field for new researches, aiming the development of products with the compounds bicyclogermacrene and germacrene D, as an alternative in the control of this culicide.