title: Protective effects of ginsenoside Rd against okadaic acid-induced neurotoxicity in vivo and in vitro.
abstract: BACKGROUND
  Panax ginseng, a traditional Chinese herbal medicine, has been widely used to restore the disease and enhance the healthy body in Asia for about 5000 years. The present study aimed to investigate the possible neuroprotective effects of ginsenoside Rd against OA-induced toxicity.
  
  
  METHODS
  Ginsenoside Rd was used in tauopahy models of Alzheimer's disease (AD). To mimic the in vivo or in vitro tau hyperphosphorylation, okadaic acid (OA), a protein phosphatase inhibitor, was bilaterally micro-infused into the cerebral ventricle of adult male Sprague-Dawley (SD) rats, or added in media of cultured cortical neurons. The phosphorylation levels of tau and the activities of protein phosphatase 2A (PP-2A) were measured and compared with ginsenoside Rd pretreated groups.
  
  
  RESULTS
  Pretreatment with ginsenoside Rd in SD rats (10mg/kg for 7 days) or in cultured cortical neurons (2.5 or 5μmol/L for 12h) reduced OA-induced neurotoxicity and tau hyperphosphorylation by enhancing the activities of PP-2A.
  
  
  CONCLUSIONS
  The result of the present work implied that ginsenoside Rd protected SD rats and cultured cortical neurons against OA-induced toxicity. The possible neuroprotective mechanism may be that ginsenoside Rd decreases OA-induced the hyperphosphorylation of tau by the increase in activities of PP-2A. Thus, this study promises that ginsenoside Rd might be a potential preventive drug candidate for AD and other tau pathology-related neuronal degenerative diseases.
authors.affiliation: Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Juanfang
authors.initials: J
authors.lastname: Liu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yan
authors.forename: Kefeng
authors.initials: K
authors.lastname: Qin
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.forename: Tian
authors.initials: T
authors.lastname: Lin
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhu
authors.forename: Tao
authors.initials: T
authors.lastname: Kang
authors.forename: Gang
authors.initials: G
authors.lastname: Zhao
mesh_terms: D000544:Alzheimer Disease / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D004195:Disease Models, Animal; D036145:Ginsenosides / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D019319:Okadaic Acid; D005894:Panax / Q000737:chemistry*; D010766:Phosphorylation; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016875:tau Proteins / Q000378:metabolism
chemical_list: D036145:Ginsenosides; D018696:Neuroprotective Agents; D010936:Plant Extracts; D016875:tau Proteins; D019319:Okadaic Acid; D054648:Protein Phosphatase 2; C049863:ginsenoside Rd