title: Effects of 1,8-cineole on Na(+) currents of dissociated superior cervical ganglia neurons.
abstract: 1,8-Cineole is a terpenoid present in many essential oil of plants with several pharmacological and biological effects, including antinociceptive, smooth muscle relaxant and ion channel activation. Also, 1,8-cineole blocked action potentials, reducing excitability of peripheral neurons. The objective of this work was to investigate effects of 1,8-cineole on Na(+) currents (INa(+)) in dissociated superior cervical ganglion neurons (SCG). Wistar rats of both sexes were used (10-12 weeks old, 200-300g). SCG's were dissected and neurons were enzymatically treated. To study 1,8-cineole effect on INa(+), the patch-clamp technique in whole-cell mode was employed. 1,8-Cineole (6.0mM) partially blocked INa(+) in SCG neurons. The effect stabilized within ∼150s and there was a partial recovery of INa(+) after washout. Current density was reduced from -105.8 to -83.7pA/pF, corresponding to a decrease to ∼20% of control. 1,8-Cineole also reduced the time-to-peak of INa(+) activation and the amplitude and decay time constants of INa(+) inactivation. Current-voltage plots revealed that 1,8-cineole left-shifted the V1/2 of both activation and inactivation curves by ∼10 and ∼20mV, respectively. In conclusion, we demonstrate that 1,8-cineole directly affects Na(+) channels of the SCG by modifying several gating parameters that are likely to be the major cause of excitability blockade.
authors: Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
authors: Francisco Walber
authors: FW
authors: Ferreira-da-Silva
authors: Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
authors: Kerly Shamyra
authors: KS
authors: da Silva-Alves
authors: Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
authors: Thaís Antônia
authors: TA
authors: Alves-Fernandes
authors: Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
authors: Andrelina Noronha
authors: AN
authors: Coelho-de-Souza
authors: Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil. Electronic address: lealcard@gmail.com.
authors: José Henrique
authors: JH
authors: Leal-Cardoso
mesh_terms: D000818:Animals; D003511:Cyclohexanols / Q000494:pharmacology*; D000077591:Eucalyptol; D005260:Female; D015640:Ion Channel Gating / Q000187:drug effects; D008297:Male; D039821:Monoterpenes / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D017208:Rats, Wistar; D026941:Sodium Channel Blockers / Q000494:pharmacology*; D015222:Sodium Channels / Q000502:physiology*; D017783:Superior Cervical Ganglion / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D003511:Cyclohexanols; D039821:Monoterpenes; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D000077591:Eucalyptol
keywords: 1,8-Cineole; Na(+) current; Patch clamp; Superior cervical ganglia