Gastrodia elata modulated activator protein 1 via c-Jun N-terminal kinase signaling pathway in kainic acid-induced epilepsy in rats

J Ethnopharmacol. 2007 Jan 19;109(2):241-7. doi: 10.1016/j.jep.2006.07.024. Epub 2006 Jul 25.

Abstract

Gastrodia elata (Orchidaceae) is a Chinese herb. Our previous study showed that Gastrodia elata is able to reduce epileptic seizures, oxygen free radicals, microglia activation, and apoptosis in kainic acid (KA)-treated rats. Activator protein 1 (AP-1) is involved in modulating the neuronal plasticity and apoptosis. Therefore, the aim of this study was to investigate the role of AP-1 in antiepileptic effect of Gastrodia elata. Gastrodia elata (0.5, 1.0g/kg) or valproic acid (VA, 250mg/kg) was administered orally in Sprague-Dawley rats for 1 week before and 2 weeks after intraperitoneal injection of KA. Protein levels of AP-1 were determined by measuring c-Jun and c-Fos proteins, and the mitogen-activated protein (MAP) kinases activations were determined by measuring the phosphorylations of extracellular signal-regulated kinases, p38, and c-Jun N-terminal kinases (JNKs) in the frontal cortex and the hippocampus of rat brain using Western blotting. These results indicated that pre-treatment with Gastrodia elata or VA activated JNK signal pathway and c-Jun expression, while post-treatment with Gastrodia elata or VA suppressed both the JNK signaling pathway and the c-Jun expression induced by KA. These findings suggested that Gastrodia elata regulated the AP-1 expression via the JNK signaling pathway in KA-induced epilepsy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anticonvulsants / pharmacology*
  • Brain / drug effects
  • Brain / metabolism
  • Drugs, Chinese Herbal / pharmacology*
  • Epilepsy / chemically induced
  • Epilepsy / drug therapy*
  • Gastrodia*
  • JNK Mitogen-Activated Protein Kinases / drug effects*
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Kainic Acid / adverse effects
  • Male
  • Phosphorylation
  • Phytotherapy / methods
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction
  • Transcription Factor AP-1 / drug effects*
  • Transcription Factor AP-1 / metabolism

Substances

  • Anticonvulsants
  • Drugs, Chinese Herbal
  • Transcription Factor AP-1
  • JNK Mitogen-Activated Protein Kinases
  • Kainic Acid