Local anaesthetic activity of monoterpenes and phenylpropanes of essential oils.
The local anaesthetic activity of a number of compounds with different structures, contained in essential oils, was studied. Anaesthetic activity was evaluated in vivo in the rabbit conjunctival reflex test and in vitro in a rat phrenic nerve-hemidiaphragm technique. Among the substances tested terpineol and trans-anethole (10(-3) - 1 microg/ml) were able to drastically reduce the electrically evoked contractions of rat phrenic nerve-hemidiaphragm in a concentration-dependent manner, but not eugenol, (-)- and (+)-citronellal, (-)- and (+)-carvone, trans cinnamaldehyde and alpha-terpinene. In the rabbit conjunctival reflex test, the treatment with a solution of terpineol and trans-anethole (10 - 100 microg/ml) effected a concentration-dependent increase in the number of stimuli required to evoke the reflex, thus confirming in vivo the local anaesthetic activity observed in vitro. Eugenol, (-)- and (+)-citronellal, trans-cinnamaldehyde, (-)- and (+)-carvone and alpha-terpinene were as ineffective in the in vivo test as they were in the in vitro results.
Ghelardini
C
C
Galeotti
N
N
Mazzanti
G
G
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D003228:Conjunctiva / Q000187:drug effects; D003964:Diaphragm / Q000187:drug effects; D006168:Guinea Pigs; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D011407:Propane / Q000031:analogs & derivatives / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D013729:Terpenes / Q000494:pharmacology*
D000779:Anesthetics, Local; D009822:Oils, Volatile; D010938:Plant Oils; D013729:Terpenes; D011407:Propane