Abstract
In this work we studied the local anaesthetic activity of the essential
oil obtained from Lavandula angustifolia Mill., a
medicinal plant traditionally used as an antispasmodic. We compared its activity
to the essential oils obtained from two citrus fruits,
Citrus reticulata Blanco and Citrus limon (L.)
Burm. f., which have no medical uses. Biological tests were also performed
on the major pure components of L. angustifolia Mill. essential oil: linalol and linalyl acetate as determined by GC
and confirmed by GC-MS. Anaesthetic activity was evaluated
in vivo in the rabbit conjunctival reflex test, and
in vitro in a rat phrenic nerve-hemidiaphragm preparation. The essential
oil of L. angustifolia, linalyl acetate and
linalol (0.01 - 10 μg/ml) but not the oils
of Citrus reticulata and Citrus
limon were able to drastically reduce, in a dose-dependent manner, the
electrically evoked contractions of rat phrenic-hemidiaphragm. In the rabbit
conjunctival reflex test treatment with a solution of essential oil of L. angustifolia, as well as linalyl acetate and
linalol (30 - 2500 μg/ml administered in the
conjunctival sac) allow a dose-dependent increase in the number of stimuli
necessary to provoke the reflex, thus confirming in vivo the local anaesthetic activity observed in vitro .
Key words
Lavandula angustifolia
- Lamiaceae - essential oil - linalol - linalyl acetate - local anaesthetic activity
