Polyphenolic content and antioxidant activity of an extractive fraction from Abies alba bark.

UNLABELLED The wood of mature Abies alba Mill. (silver fir) trees is used in construction and furniture industries, the bark being the main waste product. AIM This study aimed to investigate possible therapeutic applications of Abies alba bark waste. MATERIAL AND METHODS A raw extract and four extractive fractions were obtained from silver fir bark. They were also studied regarding their polyphenolic content (Folin-Ciocalteu assay). The ethyl acetate extractive fraction was further studied regarding its ability to scavenge free radicals (DPPH, superoxide anion and hydroxyl radicals) and to chelate ferrous ions. RESULTS AND DISCUSSION The ethyl acetate fraction contained the highest amount of polyphenols (47.72 +/- 0.38 g gallic acid equivalents/100 g). Its DPPH scavenging and ferrous ions chelating abilities (EC50 = 7.9 +/- 0.1 and 1.56 +/- 0.05 microg/ml) were comparable to those of the positive controls, catechin (EC50 = 7.10 +/- 0.05 microg/ml) and EDTA-Na2 (EC50 = 1.27 +/- 0.01 microg/ml), respectively. It also scavenged superoxide anion and hydroxyl radicals with EC50 values of 53.30 +/- 5.91 and 63.12 +/- 1.78 microg/ml, respectively. CONCLUSIONS The ability of the ethyl acetate fraction to scavenge free radicals and chelate ferrous ions justifies further studies on the possible therapeutic applications of its antioxidant potential.