title: Efficacy of aqueous extract of Hippophae rhamnoides and its bio-active flavonoids against hypoxia-induced cell death.
abstract: OBJECTIVE
  To investigate the protective efficacy of aqueous extract of Hippophae rhamnoides against chronic hypoxic injury using primary rat hepatocytes.
  
  
  METHODS
  The extract was prepared using maceration method and characterized by its phenolic and flavonoid content and chemical antioxidant capacity using ferric reducing antioxidant power assay. Hepatocytes were maintained in hypoxia chamber (3% and 1% oxygen) for 72 h. The cells kept under normoxic condition served as control. The cells were treated with the extract and flavonoids; isorhamentin, kaempferol or qurecetin-3-galactoside. After the end of exposure period; cell survival, reactive oxygen species (ROS), leakage of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), reduced glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels were measured.
  
  
  RESULTS
  The extract showed presence of high phenolic and flavonoid content with significant antioxidant activity in chemical assay. The cell exposed to hypoxia showed concentration dependent cell death and harbored higher reactive oxygen species. In addition, these cells showed significant leakage of intracellular LDH, ALT, and AST accompanied by the diminished levels/activities of GSH, GPx, and SOD. The treatment of cells with aqueous extract of H. rhamnoides reduced hypoxia-induced cell death and prevented increase in ROS levels and leakage of intracellular LDH, ALT, and AST from cells. Moreover, these cells maintained better levels/activities of GSH, GPx, and SOD in comparison to the respective controls. The major flavonoids present in aqueous extract of H. rhamnoides; quercetin-3-galactoside, kaempferol, and isorhamentin also prevented hypoxia induced cell injury individually or in combination, however, the protection offered by these compounds taken together could not match to that of the extract.
  
  
  CONCLUSIONS
  Overall the findings reveal significance of aqueous extract of H. rhamnoides in controlling ROS-meditated hypoxic injury in cells and can be useful in many hepatic complications.
authors.affiliation: Department of Biochemical Sciences, Defence Institute of Physiology and Allied Science, Lucknow Road, Timarpur, Delhi, India.
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Tulsawani
authors.forename: Rashmi
authors.initials: R
authors.lastname: Gupta
authors.forename: Kshipra
authors.initials: K
authors.lastname: Misra
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D005419:Flavonoids / Q000302:isolation & purification; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D031281:Hippophae; D000860:Hypoxia / Q000378:metabolism; D008297:Male; D010636:Phenols / Q000302:isolation & purification; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D005978:Glutathione
keywords: Hepatocytes; Hippophae rhamnoides; Hypoxia; chronic