The essential oil of Lippia alba and its components affect Drosophila behavior and synaptic physiology

Abstract

is a flowering shrub in the verbena family and its essential oil (EO) is known for its sedative, antidepressant and analgesic properties. In the Amazon region of Brazil, it is used in aquaculture to anesthetize fish during transport. Many of the specialized metabolites found in EOs presumably evolved to protect plants from herbivores, especially insects. We used to test the behavioral and physiological actions of this EO and its components. We found that a 150 min exposure to the EO vapors resulted in immobilization of adult flies. Gas chromatography-mass spectrometry identified the major components of the EO as the monoterpenes citral (59%), carvone (7%) and limonene (7%). Fly immobilization by the EO was due to citral and carvone, with citral producing more rapid effects than carvone. We tested whether the EO affected synaptic physiology by applying it to the larval neuromuscular junction. The EO delivered at 0.012% (v/v) produced over a 50% reduction in excitatory postsynaptic potential (EPSP) amplitude within 3-4 min. When the EO components were applied at 0.4 mmol l, citral and carvone produced a significant reduction in EPSP amplitude, with citral producing the largest effect. Measurement of miniature EPSP amplitudes demonstrated that citral produced over a 50% reduction in transmitter release. Calcium imaging experiments showed that citral produced about 30% reduction in presynaptic Ca influx, which likely resulted in the decrease in transmitter release. Thus, the EO blocks synaptic transmission, largely due to citral, and this likely contributes to its behavioral effects.

The essential oil of Lippia alba Mill (Lamiales:Verbenaceae) as mosquitocidal and repellent agent against Culex quinquefasciatus Say (Diptera: Culicidae) and Aedes aegypti Linn (Diptera: Culicidae)

“…The result of GC-MS analysis revealed the presence of 2, 7 octadione-1butoxy, 2-isopropenyl-5-methyl hex-4-enol, aromadendrene oxide and caryophyllene oxide as major compounds (Table 5). But the previous reports of GC-MS analysis had implied the presence of citral, carvone, limonene as the major compounds in the essential oil of L. alba (da Silva et al 2018). This variation in the composition might be depended on topographical as well as climatic condition Ngassapa et al (2003) of the place where the plant grows.…”

Identification of Bioactive Compounds against Aedes aegypti (Diptera: Culicidae) by Bioassays and in Silico Assays

“…The GC/MS analysis of all essential oils resulted in the detection of 57 constituents. Thirty‐one of these compounds were found in the essential oil of L. alba , the main constituents being α‐citral (32.32 %) and β‐citral (23.19 %), being the same compounds reported as majorities in another study involving L. alba [14] . In L. thymoides essential oil 31 compounds were detected mainly composed by eucalyptol (14.41 %) and borneol (11.63 %).…”

The evaluation of citral effects on experimental unilateral testicular ischemia/reperfusion injury

“…Increased intracellular Ca 2+ level stimulates the actuation of inflammatory pathways and cell death, particularly over mitochondria insufficiency (Ganjiani et al, 2021). At this point, da Silva et al (2018) reported that citral has a preventative effect on the influx Ca 2+ release in cells by blocking the voltage‐gated Ca 2+ channels (da Silva et al, 2018).…”