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Abstract : |
Dried ground leaves and barks of Entada africana were extracted by maceration in methanol and fractioned with chloroform, ethyle acetate and water. The total phenolic content of each fraction was determined spectrophotometrically according to Folin-Ciocalteu`s method and calculated as Tannic Acid Equivalent (TAE). Tannins and flavonoids were also determined. The total phenolic content was quite high, especially in the aqueous fraction (up to 39.7% TAE in the barks and 39.9% in the leaves). The antioxidant activity of lyophilized extracts was determined at room temperature by the means of the 2,2-diphenyl-1-picrylhydrazyl (DPPH!) colorimetric method with a detection scheme at 517 nm and expressed as EC50. The radical scavenging activity was evaluated as the difference in absorbance between a test sample and the control (methanol). Bark extracts had the best EC50, similar to those of rutoside and ascorbic acid for the aqueous and methanol fraction (5.7 and 5.3 أƒإ½أ‚آ¼g mLG1, respectively). All the other extracts were moderately active (EC50 ranging from 6.9 to 20.0 أƒإ½أ‚آ¼g mLG1), except the chloroform extracts (EC50 > 69 أƒإ½أ‚آ¼g mLG1). Except for the crude and aqueous bark extracts, no extract was cytotoxic on KB or Vero cells., |
