title: [Study on antioxidative activities of Psidium guajava Linn leaves extracts].
abstract: OBJECTIVE
  To study the antioxidative activities of the extracts from Psidium guajava Linn leaves (PGL).
  
  
  METHODS
  The PGL was submersed with distilled water, 65% ethanol and 95% ethanol respectively. The 3 extracts were obtained after the solutions were filtered, concentrated and dried. The scavenging rate to hydroxyl radicals and inhibiting rate to lipid peroxidation were analyzed for the 3 extracts. Their contents of total flavonoids were determined by ultraviolet spectrophotometry, and the components of total flavonoids were primarily identified by high performance liquid chromatography (HPLC) and ultraviolet-visible absorption spectrometry (UV).
  
  
  RESULTS
  The extracts from distilled water, 65% ethanol and 95% ethanol respectively showed effects on scavenging hydroxyl radicals and inhibiting lipid peroxidation in the dose-dependent manner, had 50% effective concentration (EC50) on scavenging hydroxyl radicals of 0.63, 0.47 and 0.58g/L, had EC50 on inhibiting lipid peroxidation of 0.20, 0.035, 0.18g/L and had total flavonoids contents of 3.28, 30.71 and 55.98g/kg respectively.
  
  
  CONCLUSIONS
  The aquatic and the ethanol extracts from PGL possess the potential antioxidative activities in the study. The flavonoids may be one of their antioxidative components.
authors: West China School of Public Health, Sichuan University, Chengdu 610041, China.
authors: Bo
authors: B
authors: Wang
authors: Shirong
authors: S
authors: Jiao
authors: Hengchuan
authors: H
authors: Liu
authors: Junrong
authors: J
authors: Hong
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D031647:Psidium / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008054:Lipid Peroxides; D010936:Plant Extracts