Planta Medica Letters 2015; 2(1): e6-e9
DOI: 10.1055/s-0034-1396320
Letter
Georg Thieme Verlag KG Stuttgart · New York

Local Anaesthetic Properties vs. Neurotoxicity for (+)- and (−)-Carvone: An Ex Vivo Electrophysiological Study

Leonidas Faliagkas
1  Department of Zoology, School of Biology, Aristotle University, Thessaloniki, Greece
,
Despoina Vokou
2  Department of Ecology, School of Biology, Aristotle University, Thessaloniki, Greece
,
George Theophilidis
1  Department of Zoology, School of Biology, Aristotle University, Thessaloniki, Greece
› Author Affiliations
Further Information

Publication History

received 26 September 2014
revised 12 November 2014

accepted 01 December 2014

Publication Date:
03 March 2015 (online)

Abstract

The two carvone enantiomers were tested for local anaesthetic activity at concentrations of 10 and 20 mM using a nerve preparation based on the isolated sciatic nerve of the frog and were found to induce similar responses. They eliminated the evoked compound action potential within 6–7 min, while there was an instant 83 to 87 % recovery when they were washed out from the nerve preparation and replaced with normal saline. Both carvones have the same pattern of action as 10 mM lidocaine, the standard local anaesthetic, but they are 3–4 times less active with respect to the time of response. When the nerves were exposed to the carvones for a period of time longer than 6–7 min, for example 1 h, there was no recovery at all of the evoked compound action potential, indicating a neurotoxic action. In contrast, when nerves were exposed under the same conditions to lidocaine and another natural compound with local anaesthetic properties, 2-heptanone, there was an 80–100 % recovery. This unusual neurotoxic effect of (+)- and (−)-carvone can be a disadvantage for their use in clinical practice.