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Planta Med 2010; 76(1): 34-40
DOI: 10.1055/s-0029-1185941
Pharmacology
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

Osthol is a Use-Dependent Blocker of Voltage-Gated Na+ Channels in Mouse Neuroblastoma N2A Cells

Yuk-Man Leung1 [*] , Yueh-Hsiung Kuo2 [*] , Chia-Chia Chao1 , Yi-Huan Tsou3 , Chun-Hsiao Chou1 , Chia-Huei Lin1 , Kar-Lok Wong4 , 5
  • 1Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
  • 2Tsuzuki Institute for Traditional Medicine, China Medical University, Taichung, Taiwan
  • 3School of Pharmacy, China Medical University, Taichung, Taiwan
  • 4Department of Anesthesia, China Medical University, Taichung, Taiwan
  • 5Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
Further Information

Publication History

received Dec. 16, 2008 revised June 4, 2009

accepted June 10, 2009

Publication Date:
28 July 2009 (online)

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Abstract

Osthol, a Chinese herbal compound, has been shown to possess vasorelaxant and neuroprotective properties. Not much is known about the effects of osthol on ionic channels, activities of which are implicated in vasorelaxation and neuroprotection. In this work we report that osthol could inhibit voltage-gated Na+ currents with state-dependence in mouse neuroblastoma N2A cells (IC50 = 12.3 µM and 31.5 µM at holding potentials of − 70 mV and − 100 mV, respectively). Current blockade was equally effective in both extracellular and intracellular application of osthol. Osthol (18 µM) did not significantly affect the kinetics and voltage-dependence of Na+ channel activation, but left-shifted the steady-state inactivation curve (V1/2 = − 60.5 mV and − 78.7 mV in the absence and presence of osthol, respectively). Osthol also mildly but significantly retarded channel recovery from inactivation (recovery time constant = 19.9 ms and 35.6 ms in the absence and presence of osthol, respectively). In addition, osthol blocked Na+ currents in a frequency-dependent fashion: blockades of 17 %, 34 % and 49 % when currents were triggered at 0.33 Hz, 1 Hz and 3.33 Hz, respectively. Taken together, our results therefore suggest that osthol blocked voltage-gated Na+ channels intracellularly with state- and frequency-dependence.

Key words

osthol - voltage‐gated Na+ channels - blockade - use‐dependence - state‐dependence - N2A cells

References

  • 1 Ko F N, Wu T S, Liou M J, Huang T F, Teng C M. Vasorelaxation of rat thoracic aorta caused by osthole isolated from Angelica pubescens.  Eur J Pharmacol. 1992;  219 29-34
    CrossrefPubMedSearch in Google Scholar
  • 2 Ogawa H, Sasai N, Kamisako T, Baba K. Effects of osthol on blood pressure and lipid metabolism in stroke-prone spontaneously hypertensive rats.  J Ethnopharmacol. 2007;  112 26-31
    CrossrefPubMedSearch in Google Scholar
  • 3 Teng C M, Lin C H, Ko F N, Wu T S, Huang T F. The relaxant action of osthole isolated from Angelica pubescens in guinea-pig trachea.  Naunyn Schmiedebergs Arch Pharmacol. 1994;  349 202-208
    PubMedSearch in Google Scholar
  • 4 Chen J, Chiou W F, Chen C C, Chen C F. Effect of the plant-extract osthole on the relaxation of rabbit corpus cavernosum tissue in vitro.  J Urol. 2000;  163 1975-1980
    CrossrefPubMedSearch in Google Scholar
  • 5 Matsuda H, Tomohiro N, Ido Y, Kubo M. Anti-allergic effects of cnidii monnieri fructus (dried fruits of Cnidium monnieri) and its major component, osthol.  Biol Pharm Bull. 2002;  25 809-812
    CrossrefPubMedSearch in Google Scholar
  • 6 Okamoto T, Kobayashi T, Yoshida S. Synthetic derivatives of osthole for the prevention of hepatitis.  Med Chem. 2007;  3 35-44
    CrossrefPubMedSearch in Google Scholar
  • 7 Shen L X, Jin L Q, Zhang D S, Xue G P. Effect of osthol on memory impairment of mice in AlCl3-induced acute senile model.  Yao Xue Xue Bao. 2002;  37 178-180
    PubMedSearch in Google Scholar
  • 8 Levi M S, Brimble M A. A review of neuroprotective agents.  Curr Med Chem. 2004;  11 2383-2397
    CrossrefPubMedSearch in Google Scholar
  • 9 Yu S P. Regulation and critical role of potassium homeostasis in apoptosis.  Prog Neurobiol. 2003;  70 363-386
    CrossrefPubMedSearch in Google Scholar
  • 10 Hu C L, Liu Z, Zeng X M, Liu Z Q, Chen X H, Zhang Z H, Mei Y A. 4-Aminopyridine, a Kv channel antagonist, prevents apoptosis of rat cerebellar granule neurons.  Neuropharmacology. 2006;  51 737-746
    CrossrefPubMedSearch in Google Scholar
  • 11 Kobayashi T, Mori Y. Ca2+ channel antagonists and neuroprotection from cerebral ischemia.  Eur J Pharmacol. 1998;  363 1-15
    CrossrefPubMedSearch in Google Scholar
  • 12 Kim S, Nah S Y, Rhim H. Neuroprotective effects of ginseng saponins against L-type Ca2+ channel-mediated cell death in rat cortical neurons.  Biochem Biophys Res Commun. 2008;  365 399-405
    CrossrefPubMedSearch in Google Scholar
  • 13 Obrenovitch T P. Neuroprotective strategies: voltage-gated Na+-channel down-modulation versus presynaptic glutamate release inhibition.  Rev Neurosci. 1998;  9 203-211
    PubMedSearch in Google Scholar
  • 14 Hewitt K E, Stys P K, Lesiuk H J. The use-dependent sodium channel blocker mexiletine is neuroprotective against global ischemic injury.  Brain Res. 2001;  898 281-287
    CrossrefPubMedSearch in Google Scholar
  • 15 Hemmings Jr H C. Neuroprotection by Na+ channel blockade.  J Neurosurg Anesthesiol. 2004;  16 100-101
    CrossrefPubMedSearch in Google Scholar
  • 16 Wu S N, Lo Y K, Chen C C, Li H F, Chiang H T. Inhibitory effect of the plant-extract osthole on L-type calcium current in NG108–15 neuronal cells.  Biochem Pharmacol. 2002;  63 199-206
    CrossrefPubMedSearch in Google Scholar
  • 17 Chao C C, Shieh J, Kuo S C, Wu B T, Hour M J, Leung Y M. HMJ-53A accelerates slow inactivation gating of voltage-gated K+ channels in mouse neuroblastoma N2A cells.  Neuropharmacology. 2008;  54 1128-1135
    CrossrefPubMedSearch in Google Scholar
  • 18 Leung Y M, Ahmed I, Sheu L, Tsushima R G, Diamant N E, Hara M, Gaisano H Y. Electrophysiological characterization of pancreatic islet cells in the mouse insulin promoter-green fluorescent protein mouse.  Endocrinology. 2005;  146 4766-4775
    CrossrefPubMedSearch in Google Scholar
  • 19 Guh J H, Yu S M, Ko F N, Wu T S, Teng C M. Antiproliferative effect in rat vascular smooth muscle cells by osthole, isolated from Angelica pubescens.  Eur J Pharmacol. 1996;  298 191-197
    CrossrefPubMedSearch in Google Scholar
  • 20 Catterall W A. From ionic currents to molecular mechanisms: the structure and function of voltage-gated sodium channels.  Neuron. 2000;  26 13-25
    CrossrefPubMedSearch in Google Scholar
  • 21 Hille B. Ion channels of excitable membranes, 3rd edition. Sunderland; Sinauer Press 2001: 131-143
    Search in Google Scholar
  • 22 Ragsdale D S, McPhee J C, Scheuer T, Catterall W A. Molecular determinants of state-dependent block of Na+ channels by local anesthetics.  Science. 1994;  265 1724-1728
    CrossrefPubMedSearch in Google Scholar
  • 23 Hwang D F, Noguchi T. Tetrodotoxin poisoning.  Adv Food Nutr Res. 2007;  52 141-236
    PubMedSearch in Google Scholar
  • 24 Wang S J, Lin T Y, Lu C W, Huang W J. Osthole and imperatorin, the active constituents of Cnidium monnieri (L.) Cusson, facilitate glutamate release from rat hippocampal nerve terminals.  Neurochem Int. 2008;  53 416-423
    CrossrefPubMedSearch in Google Scholar

1 These authors contributed equally to this work.

Dr. Yuk-Man Leung

Graduate Institute of Neural and Cognitive Sciences
China Medical University

Taichung 40402

Taiwan

R. O. C.

Phone: + 88 64 22 05 33 66 ext. 2185

Fax: + 88 64 22 07 68 53

Email: ymleung@mail.cmu.edu.tw

Dr. Kar-Lok Wong

Department of Anesthesia
China Medical University and Hospital

Taichung 40402

Taiwan

R. O. C.

Phone: + 88 64 22 05 21 21 ext. 3550

Fax: + 88 64 22 05 21 21 ext. 3598

Email: klwong@mail.cmuh.org.tw