title: Evaluation of the sesquiterpene (-)-alpha-bisabolol as a novel peripheral nervous blocker.
abstract: Essential oils are natural, complex and multi-component systems composed mainly of terpenes in addition to some other non-terpenes compounds that are widely used to prevent and treat human diseases. (-)-alpha-Bisabolol is an unsaturated monocyclic sesquiterpene alcohol found as the major constituent of many essential oils, like the German chamomile (Chamomilla recutita (L.) Rauschert), a plant reported to reduce the perception of acute pain and used for centuries for their medicinal properties. Recently, our group demonstrated the antinociceptive-like effect promoted by other terpenes could be associated with the decreased peripheral nerve excitability. Therefore, this study investigated the pharmacological activities of (-)-alpha-bisabolol on mice peripheral nervous system observing the changes on the compound action potential (CAP) characteristics. Using modified single sucrose-gap method in mice sciatic nerves, we acquired CAP recordings in the absence and presence of (-)-alpha-bisabolol (0.5, 1, 5 and 10mM). We observed that this sesquiterpene was able to reduce the neuronal excitability in a concentration-dependent manner, although, such effects were not reversed when the nerve was submitted to wash out. Assessing CAP parameters of depolarization and repolarization, we noticed similarities between (-)-alpha-bisabolol and lidocaine but not with 4-aminopyridine that are considered good blockers for sodium and potassium voltage-gated channels, respectively. Additionally, we also characterized the non-use-dependent profile of (-)-alpha-bisabolol action, in contrast to lidocaine. Thus, we suggested that decreased nervous excitability elicited by (-)-alpha-bisabolol might be caused by an irreversible blockade of voltage-dependent sodium channels.
authors.affiliation: Laboratório de Tecnologia Farmacêutica, Universidade Federal da Paraíba, João Pessoa, PB, Brazil.
authors.forename: Aron de Miranda H
authors.initials: Ade M
authors.lastname: Alves
authors.forename: Juan Carlos R
authors.initials: JC
authors.lastname: Gonçalves
authors.forename: Jader Santos
authors.initials: JS
authors.lastname: Cruz
authors.forename: Demetrius Antônio M
authors.initials: DA
authors.lastname: Araújo
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D051379:Mice; D000081222:Monocyclic Sesquiterpenes; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors; D012584:Sciatic Nerve / Q000187:drug effects* / Q000502:physiology; D012717:Sesquiterpenes / Q000494:pharmacology*; D026941:Sodium Channel Blockers / Q000494:pharmacology*
chemical_list: D000700:Analgesics; D000081222:Monocyclic Sesquiterpenes; D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated; D012717:Sesquiterpenes; D026941:Sodium Channel Blockers; C004497:bisabolol; D008012:Lidocaine; D015761:4-Aminopyridine