Iron Chelating Activity of Nepeta Crispa Willd., an Endemic Plant in the West of Iran

Background: Nepeta crispa Willd., a member of Lamiaceae family, is an annual plant native to western Iran, especially Hamedan, with many traditional uses. The plant effects have not been investigated yet. Iron chelating activity is a suitable test for measuring antioxidant activity. Objectives: The present study aimed to evaluate Iron-chelating activity of extract, fractions, and essential oil of the N. crispa, in vitro. Methods: The methanolic extract of N. crispa was prepared adopting maceration method. Then, the total methanolic extract was fractionated using hexane, chloroform, ethyl acetate, and water. The essential oil was isolated by hydrodistillation using a Clevenger-type apparatus. Chelating activity of total extract, each fraction and essential oil of N. crispa on Fe^2+ ions was determined using Iron-chelating assay. EDTA was employed as positive control. Results: EDTA as positive control had the best activity with IC50 = 0.02 ± 0.001 mg/mL, and ascorbic acid came second in this regard (IC50 = 0.386 ± 0.021 mg/mL). The hexane fraction was the most active fraction among the different fractions of N. crispa (IC50 = 0.435 ± 0.032 mg/mL). Chelating activity of hexane fraction was followed by aqueous, ethyl acetate, chloroform fractions, and methanolic extract with ICs50 of 1.433 ± 0.098, 2.158 ± 0.074 mg/mL, 3.624 ± 0.112, and 3.051 ± 0.174, respectively. The essential oil showed extremely poor activity in the tested concentrations. Conclusion: It was concluded that the n-hexane fraction had promising Iron chelating activity, and was likely capable of reducing Fe^2+ ions concentration and preventing oxidative damage.