Evaluation of the sesquiterpene (−)-α-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.

Essential oils components as a new path to understand ion channel molecular pharmacology

“…These molecules freely cross cellular membranes and may serve various signaling roles inside the cell. In addition, there are some reports indicating that essential oil plant components are active towards ion channels and receptors (Gonçalves et al, 2008;de Almeida et al, 2008;Alves et al, 2010). Apart from rational drug design and novel synthetic efforts, natural products are still been investigated for novel chemical structures that may interact with known and unknown pharmacological targets.…”

Anti-nociceptive and anti-inflammatory activities of (−)-α-bisabolol in rodents

“…Some activities have been associated with (−)-α-bisabolol such as anti-mutagenic capability (Gomes-Careneiro et al), pro-apoptotic capability in models of primary human acute leukaemia cells (Cavaliere et al) and the capacity to decrease nervous excitability supposedly associated with an irreversible blockade of voltage-dependent sodium channels (Alves et al 2010).…”

Attenuation of visceral pain in mice by the essential oil from Vanillosmopsis arborea bark

“…Visceral afferents express a wide range of membrane receptors (including vanilloid receptors, TRPV1) to chemical stimuli, which are involved in sensory signaling from the gut to the central nervous system 11 . This antinociceptive effect may be related to the high bisabolol content in EOVA, since that Alves et al 12 have just reported that bisabolol is able to reduce the neuronal excitability in a concentration--dependent manner.…”