title: Preliminary phytochemical screening and in vitro antioxidant activities of the aqueous extract of Helichrysum longifolium DC.
abstract: BACKGROUND
  Many oxidative stress related diseases are as a result of accumulation of free radicals in the body. A lot of researches are going on worldwide directed towards finding natural antioxidants of plants origins. The aims of this study were to evaluate in vitro antioxidant activities and to screen for phytochemical constituents of Helichrysum longifolium DC. [Family Asteraceae] aqueous crude extract.
  
  
  METHODS
  We assessed the antioxidant potential and phytochemical constituents of crude aqueous extract of Helichrysum longifolium using tests involving inhibition of superoxide anions, DPPH, H2O2, NO and ABTS. The flavonoid, proanthocyanidin and phenolic contents of the extract were also determined using standard phytochemical reaction methods.
  
  
  RESULTS
  Phytochemical analyses revealed the presence of tannins, flavonoids, steroids and saponins. The total phenolic content of the aqueous leaf extract was 0.499 mg gallic acid equivalent/g of extract powder. The total flavonoid and proanthocyanidin contents of the plant were 0.705 and 0.005 mg gallic acid equivalent/g of extract powder respectively. The percentage inhibition of lipid peroxide at the initial stage of oxidation showed antioxidant activity of 87% compared to those of BHT (84.6%) and gallic acid (96%). Also, the percentage inhibition of malondialdehyde by the extract showed percentage inhibition of 78% comparable to those of BHT (72.24%) and Gallic (94.82%).
  
  
  CONCLUSIONS
  Our findings provide evidence that the crude aqueous extract of H. longifolium is a potential source of natural antioxidants, and this justified its uses in folkloric medicines.
authors.affiliation: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
authors.forename: Olayinka A
authors.initials: OA
authors.lastname: Aiyegoro
authors.forename: Anthony I
authors.initials: AI
authors.lastname: Okoh
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D002084:Butylated Hydroxytoluene; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology*; D005707:Gallic Acid; D036562:Helichrysum / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008315:Malondialdehyde / Q000378:metabolism; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D010840:Phytosterols / Q000032:analysis / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves; D059808:Polyphenols; D044945:Proanthocyanidins / Q000032:analysis / Q000494:pharmacology; D012016:Reference Values; D012503:Saponins / Q000032:analysis / Q000494:pharmacology*; D013634:Tannins / Q000032:analysis / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010840:Phytosterols; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins; D012503:Saponins; D013634:Tannins; D002084:Butylated Hydroxytoluene; D008315:Malondialdehyde; D005707:Gallic Acid
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