title: Ginkgo biloba protects against intermittent hypoxia-induced memory deficits and hippocampal DNA damage in rats.
abstract: The aim of the present study was to explore the potential protective effect of Ginkgo biloba extract (EGb 761) on intermittent hypoxia (IH)-induced memory deficits and oxidative stress in rats.
  
  
  METHODS
  The passive avoidance reflex (PAR) test was employed to assess the effect of concurrent EGb 761 treatment in different dose levels on the memory deficits that were induced by concurrent long-term exposure to IH (21 days). The levels of hippocampal malondialdehyde (MDA), nitric oxide (NO), and intracellular glutathione (GSH) and the activity of glutathione peroxidase (GSH-Px) were estimated. In addition, serum and hippocampal 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were assessed to study the effect of EGb 761 on hippocampal oxidative DNA damage induced by IH.
  
  
  RESULTS
  Exposure to long-term IH in rats induced marked memory impairment that was indicated by a significant decrease in the retention latency in the PAR test. This effect was accompanied by a significant increase in hippocampal oxidative stress and DNA damage. EGb 761 that was administered in either 50- or 100-mg/kg doses per day reversed IH-induced memory deficits, an effect that was accompanied by a significant decrease in hippocampal MDA and NO levels. The antioxidant defence (GSH and GSH-Px) that was depressed by IH was significantly reactivated by EGb 761. Furthermore, serum and hippocampal levels of 8-OHdG that were elevated by IH were significantly reduced.
  
  
  CONCLUSIONS
  EGb 761 can protect against IH-induced memory impairment, oxidative stress and neuronal DNA damage, possibly through multiple mechanisms involving its potential anti-oxidative effect.
authors.affiliation: Department of Pharmacology, College of Medicine, Assiut University, Assiut, Egypt. basel post@msn.com
authors.forename: Basel A
authors.initials: BA
authors.lastname: Abdel-Wahab
authors.forename: Samy M
authors.initials: SM
authors.lastname: Abd El-Aziz
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism; D001362:Avoidance Learning / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D020441:Ginkgo biloba / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D000860:Hypoxia / Q000150:complications; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008569:Memory Disorders / Q000188:drug therapy* / Q000209:etiology; D018384:Oxidative Stress; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D020011:Protective Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D000096983:Ginkgo Extract
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants; D003849:Deoxyguanosine; D005978:Glutathione; D010936:Plant Extracts; D020011:Protective Agents; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract