Planta Med 2013; 79 - PJ22
DOI: 10.1055/s-0033-1352226

Total polyphenol content and assessment of antioxidant activity of selected medicinal plants

R Kacem 1, Y Hemissi 1, S Talbi 1, S Bouguatosha 1
  • 1Ferhat Abbas University, Faculty of Natural Sciences and Life, Department of Biology and Physiology, Setif 19000, Algeria

The present work aims to assess the total polyphenols content and In vitro antioxidant activity of aqueous and methanol extracts of three selected medicinal plants used in traditional medicine; Eucalyptus globules, Peganum harmala and Nigella sativa. The antioxidant capacity was evaluated by applying two methods; ß-carotene bleaching assay and the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging assay. The MeOH extracts presented high levels of polyphenolic compounds (up to 333 ± 0.77 µg gallic acid equivalents (GAE)/mg plant extract. The antioxidant activity of the three selected medicinal plants was found to be dose dependent with polyphenols concentration. The alcoholic extracts displayed stronger antioxidant capacity than did aqueous extracts. Using the DPPH free-radical scavenging assay, the MeOH extract of E. globulus showed the highest antioxidant activity (IC50= 14.8 ± 0.61 µg/ml). The test of β-carotene bleaching indicates that the MeOH extract of E. globulus showed the highest percentage of the antioxidant activity (69.9%). Results of this study demonstrate that leafs extracts of E. globulus possess strong antioxidant properties and therefore could be used in pharmaceutical industries.