Antioxidant and antihemolytic activities of acetone extracts of Hyssopus angustifolius flowers, leaf and stems were investigated employing different in vitro and ex vivo assay systems. IC50 for 1,1-diphenyl-2- picryl hydrazyl (DPPHΣ) radical-scavenging activity were 239.4 ± 8.4 μg/mL for flowers, 357.8 ± 11.1 μg/mL for stems and 182.5 ± 7.5 μg/mL for leaf. All extracts showed moderate nitric oxide scavenging activity. The leaf extract exhibited better hydrogen peroxide scavenging and Fe2+ chelating activity than the others (IC50 were 261.0 ± 6.2 μg/mLfor hydrogen peroxide and 534.0 ± 9.9 μg/mLfor Fe2+ chelating activity). The extracts exhibited good antioxidant activity in linoleic acid peroxidation system and weak reducing power ability. The leaf extract showed better antihemolytic activity than the flower and stem (IC50= 65.7 ± 1.8 μg/mL).
