In vitro antioxidant and antihemolytic effects of the essential oil and methanolic extract of Allium rotundum L.

Objective: A plethora of scientific evidence showed that several plant species from the genus Allium (Alliaceae) possess multiple therapeutic effects. Present paper aimed to examine the antioxidant and antihemolytic activities of the essential oil and methanol extract Allium rotundum L. through different in vitro assays.
Materials and Methods: 1,1-diphenyl-2-picryl hydroxyl radical (DPPH), nitric oxide as well as hydrogen peroxide scavenging, Fe2+ chelating, reducing power and also hemoglobin-induced linoleic acid peroxidation assay systems have been utilized to examine antioxidant effects of these samples. Total amounts of phenolic and flavonoid contents were calculated. The antihemolytic effect was investigated against hemolysis induced by hydrogen peroxide in rat erythrocytes. Also, mineral contents of plant were evaluated by atomic absorption spectroscopy.
Results: IC50 for DPPH radical-scavenging activity were 284 ± 11.64 for methanol extract and 1264 ± 45.60 µg ml-1 for essential oil, respectively. The extract has shown better reducing effects versus essential oil. The extract also demonstrated better activity in nitric oxide-scavenging activity. IC50 were 464 ± 19.68 for extract and 1093 ± 38.25 µg ml-1 for essential oil. The extract shows better activity than essential oil in Fe2+ chelating system. IC50 were 100 ± 3.75 for extract and 1223 ± 36.25 µg ml-1 for essential oil. The A. rotundum extract and essential oil showed significant H2O2 scavenging effects at dose-dependent manners. IC50 was 786 ± 29.08 mg ml-1 for essential oil. The amounts of eight elements were determined. The concentrations of elements were in the order: Mn> Fe> Zn> Cu> Ni> Cd.
Conclusions: The extract showed a higher antioxidant effect in all tested models including DPPH, nitric oxide, reducing power as well as iron chelating and antihemolytic activities than essential oil. The latter showed more potent antioxidant activity in scavenging H2O2 and lipid peroxidation model. Antioxidant activities of extract may be attributed at least in part, due to its phenolic and flavonoid contents.