title: Antioxidant activity and phytochemical screening of the methanol extracts of Euphorbia hirta L.
abstract: OBJECTIVE
  To assess antioxidant activities of different parts of Euphorbia hirta (E. hirta), and to search for new sources of safe and inexpensive antioxidants.
  
  
  METHODS
  Samples of leaves, stems, flowers and roots from E. hirta were tested for total phenolic content, and flavonoids content and in vitro antioxidant activity by diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power was measured using cyanoferrate method.
  
  
  RESULTS
  The leaves extract exhibited a maximum DPPH scavenging activity of (72.96±0.78)% followed by the flowers, roots and stems whose scavenging activities were (52.45±0.66)%, (48.59±0.97)%, and (44.42±0.94)%, respectively. The standard butylated hydroxytoluene (BHT) was (75.13±0.75)%. The IC(50) for leaves, flowers, roots, stems and BHT were 0.803, 0.972, 0.989, 1.358 and 0.794 mg/mL, respectively. The reducing power of the leaves extract was comparable with that of ascorbic acid and found to be dose dependent. Leaves extract had the highest total phenolic content [(206.17±1.95) mg GAE/g], followed by flowers, roots and stems extracts which were (117.08±3.10) mg GAE/g, (83.15±1.19) mg GAE/g, and (65.70±1.72) mg GAE/g, respectively. On the other hand, total flavonoids content also from leave had the highest value [(37.970±0.003) mg CEQ/g], followed by flowers, roots and stems extracts which were (35.200±0.002) mg CEQ/g, (24.350±0.006) mg CEQ/g, and (24.120±0.004) mg CEQ/g, respectively. HPTLC bioautography analysis of phenolic and antioxidant substance revealed phenolic compounds. Phytochemical screening of E. hirta leaf extract revealed the presence of reducing sugars, terpenoids, alkaloids, steroids, tannins, flavanoids and phenolic compounds.
  
  
  CONCLUSIONS
  These results suggeste that E. hirta have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidant agents, which can be used to treat various oxidative stress-related diseases.
authors.affiliation: Biology Division, School of Distance Education, Universiti Sains Malaysia, USM 11800, Pulau Pinang, Malaysia.
authors.forename: Abu Arra
authors.initials: AA
authors.lastname: Basma
authors.forename: Zuraini
authors.initials: Z
authors.lastname: Zakaria
authors.forename: Lacimanan Yoga
authors.initials: LY
authors.lastname: Latha
authors.forename: Sreenivasan
authors.initials: S
authors.lastname: Sasidharan
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D028481:Euphorbia / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D010636:Phenols / Q000032:analysis; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl