title: [The pharmacological mechanism of gastrodin on calcitonin gene-related peptide of cultured rat trigeminal ganglion].
abstract: The Chinese herbal medicine Tianma (Gastrodia elata) has been used for treating and preventing primary headache over thousands of years, but the exact pharmacological mechanism of the main bioactive ingredient gastrodin remains unclear. In present study, the effects of gastrodin on calcitonin gene-related peptide (CGRP) and phosphorylated extracellular signal-regulated kinase1/2 (pERK1/2) expression were observed in rat trigeminal ganglion (TG) after in vitro organ culture to explore the underlying intracellular mechanism of gastrodin on primary vascular-associated headache. CGRP-immunoreactivity (CGRP-ir) positive neurons count, positive area, mean optical density and integrated optical density by means of immunohistochemistry stain were compared at different concentrations of gastrodin, which was separately co-incubated with DMEM in SD rat TG for 24 hours. Only at 5 or 10 mmol L(-1) concentration, gastrodin demonstrated significantly concentration-dependent reduction of CGRP-ir (+) expression and its action closed to 1.2 mmol L(-1) sumatriptan succinate. While at 2.5, 20, and 40 mmol L(-1) concentration, gastrodin did not show remarkable effects on CGRP-ir (+) expression. The optimal concentration of gastrodin (5 and 10 mmol L(-1)) similarly inhibited CGRP-mRNA expression level separately compared with 1.2 mmol L(-1) sumatriptan succinate and 10 micromol L(-1) flunarizine hydrochloride, which was quantitatively analyzed by real-time PCR (RT-PCR). pERK1/2 level was examined by Western blotting after co-cultured with optimal concentration of gastrodin and effective specific ERK1/2 pathway inhibitors PD98059, U0126. The result indicated that gastrodin significantly reduced pERK1/2 protein actions similarly to ERK1/2 pathway specific blockade. It suggests ERK1/2 signaling transduction pathway may be involved in gastrodin intracellular mechanism. This study indicates gastrodin (5 and 10 mmol L(-1)) can remarkably reduce CGRP-ir (+) neuron, CGRP-mRNA and pERK1/2 expression level in cultured rat TG, with its actions similar to the effective concentration of sumatriptan succinate, flunarizine hydrochloride and specific ERK1/2 pathway blocker. The intracellular signaling transduction ERK1/2 pathway may be involved in the gastrodin reducing CGRP up-regulation in rat TG after organ culture.
authors.affiliation: Department of Neurology, First Affiliated Hospital, Key Laboratory of Environment and Genes Related Disease, Ministry of Education, Medical School of Xi'an Jiaotong University, Xi'an 710061, China.
authors.forename: Guo-Gang
authors.initials: GG
authors.lastname: Luo
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Fan
authors.forename: Xing-Yun
authors.initials: XY
authors.lastname: Yuan
authors.forename: Bo-Bo
authors.initials: BB
authors.lastname: Yuan
authors.forename: She-Min
authors.initials: SM
authors.lastname: Lü
authors.forename: Yong-Xiao
authors.initials: YX
authors.lastname: Cao
authors.forename: Cang-Bao
authors.initials: CB
authors.lastname: Xu
mesh_terms: D000818:Animals; D001592:Benzyl Alcohols / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D002070:Butadienes / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology; D005444:Flunarizine / Q000494:pharmacology; D031668:Gastrodia / Q000737:chemistry; D005960:Glucosides / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D009924:Organ Culture Techniques; D010946:Plants, Medicinal / Q000737:chemistry; D012333:RNA, Messenger; D051381:Rats; D017207:Rats, Sprague-Dawley; D018170:Sumatriptan / Q000494:pharmacology; D012668:Trigeminal Ganglion / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001592:Benzyl Alcohols; D002070:Butadienes; D005419:Flavonoids; D005960:Glucosides; D009570:Nitriles; D012333:RNA, Messenger; C113580:U 0126; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C045345:gastrodin; D018170:Sumatriptan; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D015740:Calcitonin Gene-Related Peptide; D005444:Flunarizine; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one