Evaluation of Physiological Activity of Traditional Welsh Onion (Allium fistulosum L.)

Purpose: This study was conducted to evaluate physiological activities, such as antioxidant activity and enzyme activity, of hot water extract of the four parts (flower, leaf and pseudostem, stem, and root) of traditional Welsh onion (Allium fistulosum L.) and then to provide basic data on traditional Welsh onion to support future research.Methods: Four parts of traditional Welsh onion plant were extracted with water heated at 80℃. Antioxidative and enzymatic activities, such as total polyphenol content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis-3-ethylbenzothiazoline–6-sulfonic acid (ABTS) radical scavenging activity, and the inhibitory activity on α-glucosidase, tyrosinase, and elastase enzymes, were measured.Results: Out of the hot water extract of the different parts, Allium fistulosum flower (AFF) extract had the highest content of antioxidants. In the Allium fistulosum leaf and pseudostem (AFLP), Allium fistulosum stem (AFS), and Allium fistulosum root (AFR) extracts, the total polyphenol content and DPPH radical scavenging activity of the root were high, and AFS had high total flavonoid content and ABTS radical scavenging activity. Regarding enzyme activity, α-glucosidase and elastase inhibitory activities were the highest in AFR, and tyrosinase inhibitory activity was the highest in AFS.Conclusion: We confirmed the physiological activity of the hot water extract of four parts of traditional Welsh onion. Our findings provide basic data for research into traditional Welsh onion, and can facilitate its future development as a functional material.