title: Effects of ginkgo biloba extract on cultured human retinal pigment epithelial cells under chemical hypoxia.
abstract: OBJECTIVE
  To investigate the effects of Ginkgo biloba extract (GBE) on expression of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) in retinal pigment epithelial (RPE) cells under chemical hypoxia.
  
  
  METHODS
  RPE cells (ARPE-19) were cultured in either untreated media (control group), media treated with 200 μM cobalt chloride (hypoxia group) or media treated with both 200 μM cobalt chloride and 100 μg/ml GBE (hypoxia + GBE group) for various amounts of time. HIF-1α and VEGF expression were compared between groups. HIF-1α and VEGF messenger RNA (mRNA) were quantified using real-time polymerase chain reaction (PCR). HIF-1α of extracted nuclei and VEGF of the media were quantified using enzyme-linked immunosorbent assay (ELISA). The expression of HIF-1α was also assessed with Western blot and immunocytochemistry.
  
  
  RESULTS
  HIF-1α mRNA, VEGF mRNA, HIF-1α and VEGF levels were higher in the hypoxia group compared with the control group; however, real-time PCR revealed decreased expression of HIF-1α mRNA and VEGF mRNA in the hypoxia + GBE group compared with the hypoxia group. In the ELISA, the HIF-1α and VEGF protein concentrations also decreased with GBE treatment. Western blot and immunostaining showed that the intensity of HIF-1α signals in the hypoxia + GBE group was lower than that of the hypoxia group.
  
  
  CONCLUSIONS
  GBE reduced HIF-1α and VEGF expression in RPE cells cultured under chemical hypoxia in vitro.
authors.affiliation: Department of Ophthalmology, Dongguk University Ilsan Hospital , Goyang , South Korea and.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Oh
authors.forename: Jaeryung
authors.initials: J
authors.lastname: Oh
authors.forename: Ariunaa
authors.initials: A
authors.lastname: Togloom
authors.forename: Seong-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Kuhl
authors.initials: K
authors.lastname: Huh
mesh_terms: D016587:Antimutagenic Agents / Q000494:pharmacology; D015687:Cell Hypoxia / Q000187:drug effects; D002478:Cells, Cultured; D003035:Cobalt / Q000494:pharmacology; D020441:Ginkgo biloba / Q000737:chemistry*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D008268:Macular Degeneration / Q000188:drug therapy* / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D016587:Antimutagenic Agents; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D010936:Plant Extracts; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D003035:Cobalt; C018021:cobaltous chloride