, Volume 221, Issue 4, pp 575–587 | Cite as

Characterizing the effects of Eugenol on neuronal ionic currents and hyperexcitability

  • Chin-Wei Huang
  • Julie Chi Chow
  • Jing-Jane Tsai
  • Sheng-Nan Wu
Original Investigation



Eugenol (EUG, 4-allyl-2-methoxyphenol), the main component of essential oil extracted from cloves, has various uses in medicine because of its potential to modulate neuronal excitability. However, its effects on the ionic mechanisms remains incompletely understood.


We aimed to investigate EUG’s effects on neuronal ionic currents and excitability, especially on voltage-gated ion currents, and to verify the effects on a hyperexcitability-temporal lobe seizure model.


With the aid of patch-clamp technology, we first investigated the effects of EUG on ionic currents in NG108-15 neuronal cells differentiated with cyclic AMP. We then used modified Pinsky–Rinzel simulation modeling to evaluate its effects on spontaneous action potentials (APs). Finally, we investigated its effects on pilocarpine-induced seizures in rats.


EUG depressed the transient and late components of I Na in the neurons. It not only increased the degree of I Na inactivation, but specifically suppressed the non-inactivating I Na (I Na(NI)). Its inhibition of I Na(NI) was reversed by tefluthrin. In addition, EUG diminished L-type Ca2+ current and delayed rectifier K+ current only at higher concentrations. EUG’s effects on APs frequency reduction was verified by the simulation modeling. In pilocarpine-induced seizures, the EUG-treated rats showed no shorter seizure latency but a lower seizure severity and mortality than the control rats. The EUG’s effect on seizure severity was occluded by the I Na(NI) antagonist riluzole.


The synergistic blocking effects of I Na and I Na(NI) contributes to the main mechanism through which EUG affects the firing of neuronal APs and modulate neuronal hyperexcitability such as pilocarpine-induced temporal lobe seizures.


Eugenol Na+ current Ca2+ current K+ current Action potential Neuron 



This research project was funded by the National Science Council (NSC-98-2320-B-006-027-MY3 and NSC-98-2314-B-006-042-MY2) and the Program for Promoting Academic Excellence and Developing World Class Research Centers, Ministry of Education, Taiwan. This work was also supported in part by a grant from Buddhist Dalin Tzu-Chi General Hospital (DTCRD98-08), Chiayi County, Taiwan. The authors are grateful to Dr. Dong Chun Wu (Department of Neurology, University of British Columbia, Canada) for his critical comments on the manuscript.

Conflicts of interest

None of the authors in this study have any potential conflict of interest or financial interests to disclose.


  1. Ardjmand A, Fathollahi Y, Sayyah M, Kamalinejad M, Omrani A (2006) Eugenol depresses synaptic transmission but does not prevent the induction of long-term potentiation in the CA1 region of rat hippocampal slices. Phytomedicine 13:146–151PubMedCrossRefGoogle Scholar
  2. Benarroch EE (2010) Neuronal voltage-gated calcium channels: brief overview of their function and clinical implications in neurology. Neurology 74:1310–1315PubMedCrossRefGoogle Scholar
  3. Bender IB (2000) Pupal pain diagnosis—a review. J Endod 26:175–179PubMedCrossRefGoogle Scholar
  4. Black JA, Liu S, Tanaka M, Cummins TR, Waxman SG (2004) Changes in the expression of tetrodotoxin-sensitive sodium channels within dorsal root ganglia neurons in inflammatory pain. Pain 108:237–247PubMedCrossRefGoogle Scholar
  5. Chen SJ, Huang YC, Wu BN, Chen IJ (1997) Eugenolol: an eugenol-derived β-adrenoceptor blocker with partial β2-agonist and calcium mobilization inhibition associated vasorelaxant activities. Drug Dev Res 40:239–250CrossRefGoogle Scholar
  6. Chen BS, Peng H, Wu SN (2009) Dexmedetomidine, an α2-adrenergic agonist, inhibits neuronal delayed-rectifier potassium current and sodium current. Br J Anaesth 103:244–254PubMedCrossRefGoogle Scholar
  7. Chen S, Su H, Yue C, Remy S, Royeck M, Sochivco D, Opitz T, Beck H, Yaari Y (2011) An increase in persistent sodium current contributes to intrinsic neuronal bursting after status epilepticus. J Neurophysiol 105:117–129PubMedCrossRefGoogle Scholar
  8. Cho JS, Kin TH, Lim JM, Song JH (2008) Effects of eugenol on Na+ currents in rat dorsal root ganglion neurons. Brain Res 1243:53–62PubMedCrossRefGoogle Scholar
  9. Chung G, Rhee JN, Jung SJ, Kim JS, Oh SB (2008) Modulation of CaV2.3 calcium channel currents by eugenol. J Dent Res 87:137–141PubMedCrossRefGoogle Scholar
  10. Cifelli P, Grace AA (2011) Pilocarpine-induced temporal lobe epilepsy in the rat is associated with increased dopamine neuron activity. Int J Neuropsychopharmacol 12:1–8CrossRefGoogle Scholar
  11. Coetzee WA, Amarillo Y, Chiu J, Chow A, Lau D, McCormack T, Moreno H, Nadal MS, Ozaita A, Pountney D, Saganich M, Vega-Saenz de Miera E, Rudy B (1999) Molecular diversity of K+ channels. Ann N Y Acad Sci 868:233–285PubMedCrossRefGoogle Scholar
  12. Dallmeier K, Carlini EA (1981) Anesthetic, hypothermic, myorelaxant and anticonvulsant effects of synthetic eugenol derivatives and natural analogues. Pharmacology 22:113–127PubMedCrossRefGoogle Scholar
  13. Dallmeier K, Zelger JL, Carlini EA (1983) New anticonvulsants derived from 4-allyl-2-methoxyphenol (Eugenol): comparison with common antiepileptics in mice. Pharmacology 27:40–49CrossRefGoogle Scholar
  14. Damiani CE, Rossoni LV, Vassallo DV (2003) Vasorelaxant effects of eugenol on rat thoracic aorta. Vascul Pharmacol 40:59–66PubMedCrossRefGoogle Scholar
  15. Damiani CE, Moreira CM, Zhang HT, Creazzo TL, Vassallo DV (2004) Effects of eugenol, an essential oil, on the mechanical and electrical activities of cardiac muscle. J Cardiovasc Pharmacol 44:688–695PubMedCrossRefGoogle Scholar
  16. Djouhri L, Newton R, Levinson SR, Berry CM, Carruthers B, Lawson SN (2003) Sensory and electrophysiological properties of guinea-pig sensory neurones expressing NaV1.7 (PN1) Na+ channel a subunit protein. J Physiol 546:565–576PubMedCrossRefGoogle Scholar
  17. Duarte FS, Gavioli EC, Duzzioni M, Hoeller AA, Canteras NS, De Lima TC (2010) Short- and long-term anxiogenic effects induced by a single injection of subconvulsant doses of pilocarpine in rats: investigation of the putative role of hippocampal pathways. Psychopharmacology (Berl) 212:653–661CrossRefGoogle Scholar
  18. Earl DE, Tietz EI (2011) Inhibition of recombinant L-type voltage-gated calcium channels by positive allosteric modulators of GABAA receptors. J Pharmacol Exp Ther 337:301–311PubMedCrossRefGoogle Scholar
  19. Freire CM, Marques MO, Costa M (2006) Effects of seasonal variation on the central nervous system activity of Ocimum gratissimum L. essential oil. J Ethnopharmacol 105:161–166PubMedCrossRefGoogle Scholar
  20. He YL, Zhan XQ, Yang G, Sun J, Mei YA (2010) Amoxapine inhibits the delayed rectifier outward K + current in mouse cortical neurons via cAMP/protein kinase A pathways. J Pharmacol Exp Ther 332:437–445PubMedCrossRefGoogle Scholar
  21. Huang YC, Wu BN, Lin YT, Chen SJ, Chiu CC, Cheng CJ, Chen IJ (1999) Eugenodilol: a third-generation β-adrenoceptor blocker, derived from eugenol, with α-adrenoceptor blocking and β2-adrenoceptor agonist-associated vasorelaxant activities. J Cardiovasc Pharmacol 34:10–20PubMedCrossRefGoogle Scholar
  22. Huang CW, Huang CC, Lin MW, Tsai JJ, Wu SN (2008) The synergistic inhibitory actions of oxcarbazepine on voltage-gated sodium and potassium currents in differentiated NG108-15 neuronal cells and model neurons. Int J Neuropsychopharmacol 11:597–610PubMedCrossRefGoogle Scholar
  23. Huang CW, Cheng JT, Tsai JJ, Wu SN, Huang CC (2009) Diabetic hyperglycemia aggravates seizures and status epilepticus-induced hippocampal damage. Neurotox Res 15:71–81PubMedCrossRefGoogle Scholar
  24. Huang CW, Wu SN, Cheng JT, Tsai JJ, Huang CC (2010) Diazoxide reduces status epilepticus neuron damage in diabetes. Neurotox Res 17:305–316PubMedCrossRefGoogle Scholar
  25. Huang CW, Wu YJ, Wu SN (2011) Modification of activation kinetics of delayed rectifier K + currents and neuronal excitability by methyl-β-cyclodextrin. Neuroscience 176:431–441PubMedCrossRefGoogle Scholar
  26. Irie Y, Keung WM (2003) Rhizoma acori graminei and its active principles protect PC-12 cells from the toxic effect of amyloid-β peptide. Brain Res 963:282–289PubMedCrossRefGoogle Scholar
  27. Kawaguchi A, Asano H, Matsushima K, Wada T, Yoshida S, Ichida S (2007) Enhancement of sodium current in NG108-15 cells during neural differentiation is mainly due to an increase in NaV1.7 expression. Neurochem Res 32:1469–1475PubMedCrossRefGoogle Scholar
  28. Köseoğlu BG, Tanrikulu S, Sübay RK, Sencer S (2006) Anesthesia following overfilling of a root canal sealer into the mandibular canal: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 101:803–806PubMedCrossRefGoogle Scholar
  29. Lin MW, Yang SR, Huang MH, Wu SN (2004) Stimulatory actions of caffeic acid phenethyl ester, a known inhibitor of NF-kappaB activation, on Ca2+-activated K+ current in pituitary GH3 cells. J Biol Chem 279:26885–26892PubMedCrossRefGoogle Scholar
  30. Lin MW, Wang YJ, Liu SI, Lin AA, Lo YC, Wu SN (2008) Characterization of aconitine-induced block of delayed rectifier K+ current in differentiated NG108-15 neuronal cells. Neuropharmacology 54:912–923PubMedCrossRefGoogle Scholar
  31. Lionnet L, Beaudry F, Vachon P (2010) Intrathecal eugenol administration alleviates neuropathic pain in male Sprague–Dawley rats. Phytother Res 24:1645–1653PubMedCrossRefGoogle Scholar
  32. Lossin C, Wang DW, Rhodes TH, Vanoye CG, George AL (2002) Molecular basis of an inherited epilepsy. Neuron 34:877–884PubMedCrossRefGoogle Scholar
  33. Mathew SJ, Murrough JW, aan het Rot M, Collins KA, Reich DL, Charney DS (2010) Riluzole for relapse prevention following intravenous ketamine in treatment-resistant depression: a pilot randomized, placebo-controlled continuation trial. Int J Neuropsychopharmacol 13:71–82PubMedCrossRefGoogle Scholar
  34. Meves H, Schwarz JR, Wulfsen I (1999) Separation of M-like current and ERG current in NG108-15 cells. Br J Pharmacol 127:1213–1223PubMedCrossRefGoogle Scholar
  35. Müller M, Pape HC, Speckmann EJ, Gorji A (2006) Effect of eugenol on spreading depression and epileptiform discharges in rat neocortical and hippocampal tissues. Neuroscience 140:743–751PubMedCrossRefGoogle Scholar
  36. Ni Y, Zhao X, Bao G, Zou L, Teng L, Wang Z, Song M, Xiong J, Bai Y, Pei G (2006) Activation of β2-adrenergic receptor stimulates γ-secretase activity and accelerates amyloid plaque formation. Nat Med 12:1390–1396PubMedCrossRefGoogle Scholar
  37. Ohkubo T, Kitamura K (1997) Eugenol activates Ca2+-permeable currents in rat dorsal root ganglion cells. J Dent Res 76:1737–1744PubMedCrossRefGoogle Scholar
  38. Park CK, Kim K, Jung SJ, Kim MJ, Ahn DK, Hong SD, Kim JS, Oh SB (2009) Molecular mechanism for local anesthetic action of eugenol in the rat trigeminal system. Pain 144:84–94PubMedCrossRefGoogle Scholar
  39. Peña F, Tapia R (2000) Seizures and neurodegeneration induced by 4-aminopyridine in rat hippocampus in vivo: role of glutamate- and GABA-mediated neurotransmission and of ion channels. Neuroscience 101:547–561PubMedCrossRefGoogle Scholar
  40. Pinsky PF, Rinzel J (1994) Intrinsic and network rhythmogenesis in a reduced Traub model for CA3 neurons. J Comput Neurosci 1:39–60PubMedCrossRefGoogle Scholar
  41. Pitkanen A, Schwartzkroin PA, Moshe SL (2006) Models of seizures and epilepsy. Elsevier Academic Press, BurlingtonGoogle Scholar
  42. Pourgholami MH, Kamalinejad M, Javadi M, Majzoob S, Sayyah M (1999) Evaluation of the anticonvulsant activity of the essential oil of Eugenia caryophyllata in male mice. J Ethnopharmacol 64:167–171PubMedCrossRefGoogle Scholar
  43. Racine RJ, Burnham WM, Gartner JG, Levitan D (1973) Rates of motor seizure development in rats subjected to electrical brain stimulation: strain and inter-stimulation interval effects. Electroencephalogr Clin Neurophysiol 35:553–556PubMedCrossRefGoogle Scholar
  44. Sayyah M, Valizadeh J, Kamalinejad M (2002) Anticonvulsant activity of the leaf essential oil of Laurus nobilis against pentylenetetrazole- and maximal electroshock-induced seizures. Phytomedicine 9:212–216PubMedCrossRefGoogle Scholar
  45. Segal MM (2002) Sodium channels and epilepsy electrophysiology. Novartis Found Symp 241:173–180PubMedCrossRefGoogle Scholar
  46. Segal MM, Douglas AF (1997) Late sodium channel openings underlying epileptiform activity are preferentially diminished by the anticonvulsant phenytoin. J Neurophysiol 77:3021–3034PubMedGoogle Scholar
  47. Sensch O, Vierling W, Brandt W, Reiter M (2000) Effects of inhibition of calcium and potassium currents in guinea-pig cardiac contraction: comparison of β-caryophyllene oxide, eugenol, and nifedpine. Br J Pharmacol 131:1089–1096PubMedCrossRefGoogle Scholar
  48. Stafstrom CE (2007) Persistent sodium current and its role in epilepsy. Epilepsy Curr 7:15–22PubMedCrossRefGoogle Scholar
  49. Tsai TY, Tsai YC, Wu SN, Liu YC (2006) Tramadol-induced blockade of delayed rectifier potassium current in NG108-15 neuronal cells. Eur J Pain 10:597–601PubMedCrossRefGoogle Scholar
  50. Urbani A, Belluzzi O (2000) Riluzole inhibits the persistent sodium current in mammalian CNS neurons. Eur J Neurosci 12:3567–3574PubMedCrossRefGoogle Scholar
  51. Warren CA, Mok L, Gondon S, Fouad AF, Gold MS (2008) Quantification of neural protein in extirpated tooth pulp. J Endod 34:7–10PubMedCrossRefGoogle Scholar
  52. Wie MB, Won MH, Lee KH, Shin JH, Lee JC, Suh HW, Song DK, Kim YH (1997) Eugenol protects neuronal cells from excitotoxic and oxidative injury in primary cortical cultures. Neurosci Lett 225:93–96PubMedCrossRefGoogle Scholar
  53. Won MH, Lee JC, Kim YH, Song DK, Suh HW, Oh YS, Kim JH, Shin TK, Lee YJ, Wie MB (1998) Postischemic hypothermia induced by eugenol protects hippocampal neurons from global ischemia gerbils. Neurosci Lett 254:101–104PubMedCrossRefGoogle Scholar
  54. Wu SN, Li HF, Jan CR (1998) Regulation of Ca2+-activated nonselective cationic currents in rat pituitary GH3 cells: involvement in L-type Ca2+ current. Brain Res 812:133–141PubMedCrossRefGoogle Scholar
  55. Wu BN, Shen KP, Lin RJ, Huang YC, Chiang LC, Lo YC, Lin CY, Chen IJ (2000) Lipid solubility of vasodilatory vanilloid-type β-blockers on the functional and binding activities of β-adrenoceptor subtypes. Gen Pharmacol 34:321–328PubMedCrossRefGoogle Scholar
  56. Wu SN, Lo YK, Chen H, Li HF, Chiang HT (2001) Rutaecarpine-induced block of delayed rectifier K+ current in NG108-15 neuronal cells. Neuropharmacology 41:834–843PubMedCrossRefGoogle Scholar
  57. Wu SN, Chen BS, Hsu TI, Peng H, Wu YH, Lo YC (2009a) Analytical studies of rapidly inactivating and noninactivating sodium currents in differentiated NG108-15 neuronal cells. J Theor Biol 259:828–836PubMedCrossRefGoogle Scholar
  58. Wu SN, Chen BS, Wu YH, Peng H, Chen LT (2009b) The mechanism of the actions of oxaliplatin on ion currents and action potentials in differentiated NG108-15 neuronal cells. Neurotoxicology 30:677–685PubMedCrossRefGoogle Scholar
  59. Wu SN, Wu YH, Chen BS, Lo YC, Liu YC (2009c) Underlying mechanism of actions of tefluthrin, a pyrethroid insecticide, on voltage-gated ion currents and on action currents in pituitary tumor (GH3) cells and GnRH-secreting (GT1-7) neurons. Toxicology 258:70–77PubMedCrossRefGoogle Scholar
  60. Yang BH, Piao ZG, Kim YB, Lee CH, Lee JK, Park K, Kim JS, Oh SB (2003) Activation of vanilloid receptor 1 (VR1) by eugenol. J Dent Res 82:781–785PubMedCrossRefGoogle Scholar
  61. Zgrajka W, Nieoczym D, Czuczwar M, Kiś J, Brzana W, Wlaź P, Turski WA (2010) Evidences for pharmacokinetic interaction of riluzole and topiramate with pilocarpine in pilocarpine-induced seizures in rats. Epilepsy Res 88:269–274PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Chin-Wei Huang
    • 1
  • Julie Chi Chow
    • 2
  • Jing-Jane Tsai
    • 1
  • Sheng-Nan Wu
    • 3
    • 4
  1. 1.Department of NeurologyNational Cheng Kung University HospitalTainanTaiwan
  2. 2.Department of Pediatric NeurologyChi-Mei Foundation Medical CenterTainanTaiwan
  3. 3.Department of PhysiologyNational Cheng Kung University Medical CollegeTainanTaiwan
  4. 4.Institute of Basic Medical SciencesNational Cheng Kung University Medical CollegeTainanTaiwan

Personalised recommendations