ABSTRACT
Extracts of 4 medicinal and aromatic plants were investigated for their antioxidant potency employing six various established in vitro system: H. officinalis L. var. angustifolius aerial parts, C. speciosum flowers, V. odorata and B. hyrcana leaves.With regard to IC5o values [micro g/ m], the order in DPPH radical-scavenging were CS [585.6] > HO [311] > VO [245.1] > and BH [113.1]. Effectiveness in reducing powers were high and in a descending order of HO > CS > BH > VO [at the concentrations of 25-800 micro g/ ml]. IC[50] for Fe[2+] chelating ability were 188, 750 and 980 micro g/ ml for VO, CS and HO, respectively. BH extract has shown only 38% inhibition at 800 micro g/ ml. The extracts showed weak nitric oxide-scavenging activity. All extracts exhibited very low and moderate concentration-dependent antioxidant activity in FTC methods. IC[50] for scavenging of H[2]O[2] were 169 for BH, 175 for CS, 640 for VO and 663 microg/ ml for HO. The content of total phenolic compounds and flavonoids were measured in plant extracts. The data obtained in the in vitro models clearly establish the antioxidant potency of all extracts