Phenolic Content and Antioxidant Activity of Hydroethanolic and Aqueous Extracts of the Inflorescences of Allium sphaerocephalon L.

Abstract

The objective of this effort is to quantify the amounts of phenolics and the in vitro antioxidant capacities of Allium sphaerocephalon L. flowers’ hydroethanolic (EOH) and aqueous (AQE) extracts. The two extracts' total phenolic (TPC) and flavonoid content (TFC) were determined spectrophotometrically. Results showed the extraction yield obtained by EOH and AQE were 18.30% and 11.80%, respectively. The EOH gave higher amounts of TPC (12.73±0.91µg GAE/mg DW) and TFC (7.67±0.24µg QE/mg DW) than AQE (TPC = 9.71±0.53µg GAE/mg DW and TFC= 5.68±0.90µg QE/ mg DW). Five techniques were used to train antioxidant activity. The EOH extract had high activity in DPPH radical scavenging capacities and β-carotene bleaching assay, while the AQE extract had high activity in metal chelating ions and reducing power assay. However, both extracts had no different significance in cupric-reducing capacity. A moderate quantity of flavonoids and polyphenols, as well as a satisfactory level of antioxidant activity, were observed in both preparations derived from the flowers of A. sphaerocephalon L., where this activity is not all fully related to the amount of phenolic compounds.