Free Radical Scavenging and Antioxidant Activities of Dorema aitchisonii

The aim of this study was to investigate the antioxidant properties of the aerial parts of Dorema aitchisonii by employing various in vitro assay systems including 1,1-diphenyl-2-picryl hydrazyl radical, nitric oxide and hydrogen peroxide-scavenging activities, Fe2+ chelating ability, reducing power and hemoglobin-induced linoleic acid peroxidation. Antihemolytic activity was investigated against H2O2 induced hemolysis in rat erythrocytes. Gallic acid, rutin, quercetin and cumarin contents of the preparation were determined by HPLC with diode array detector (HPLC/DAD). The IC50 for DPPH radical-scavenging activity was 488 +/- 18 mu g/mL. The extract showed weak NO scavenging activity in the range of 0.4 and 3.2 ing/mL, as well as Fe2+ chelating ability (IC50 = 778 +/- 22 mu g/mL). The extract was effective in inhibiting hemoglobin-induced linoleic acid peroxidation, but its activity was less than Vitamin C (p < 0.01). The extract was capable of scavenging H2O2 in a concentration-dependent manner with an IC50 211 +/- 11 mu g/mL. The extract exhibited good antihemolytic activity with an IC50 385 +/- 15 mu g/mL (the corresponding value for Vitamin C being 235 +/- 9 mu g/mL). The total content of phenolic compounds was 41.2 +/- 1.9 mg gallic acid equivalents/g and the total flavonoid content was 13.8 +/- 0.8 mg quercetin equivalents/g. The extract contained 7.27 mu g rutin and 0.011 mu g gallic acid/mg extract, but cumarin and quercetin were present in trace amounts. In spite of presence of phenolic and flavonoid content, especially rutin, D. aitchisonii show weak antioxidant activity, but its antihemolytic activity was good.