Phenolic Constituents of Anethum graveolens Seed Extracts: Chemical Profile and Antioxidant Effect Studies

Abstract

The Aim of the Research: Anethum graveolens (dill) is a common herb used in traditional Romanian cuisine, as well as in phytotherapy. Dill seeds have been reported to be rich in antioxidants. As interest in food additives of natural origin has increased in recent years, the purpose of this paper was to study the composition and antioxidant potential of Romanian dill seeds. Methodology: In this study, the total phenolics contents, the phenolic profile, and the antioxidant properties of the methanolic and hydromethanolic extracts of Romanian dill seeds were investigated. Folin-Ciocalteu assay, DPPH spectrophotometrically method and reverse-phase high-performance liquid chromatography RP-HPLC, respectively were applied. Results: The highest content of total phenolics was found in acidified methanol samples (46.5 - 46.8 mg GAE/g dry seeds). RP-HPLC analysis highlights important content of quercetin, kaempferol, caffeic acid, sinapic acid, gallic acid, vanillic acid, (±) - catechin and umbelliferone. Antioxidant activity, measured via DPPH free radical scavenging ability, showed very high values (93.5 - 95.6% for the crude extracts and 67.5 - 93.2% for extracts at a concentration of 0.25 mg/mL). Methanolic extract exhibited the best IC50 value (88.7 ± 0.01 μg/mL). Conclusion: All experiments proved the antioxidant activity of dill seed extracts.