Comparative Study on the Phenolic Content, Antioxidant Properties and HPLC Fingerprinting of Three Varieties of C elosia Species

In this study, the phenolic content, characterization and antioxidant properties of aqueous extracts of three varieties of Celosia species were assessed. Celosia laxa had significantly (P < 0.05) higher total phenol and flavonoid contents than Celosia argentea (red variant) and Celosia argentea (green variant). Gallic acid, caffeic acid, quercetin and rutin were found in the three species of Celosia investigated. Rosmarinic acid and phenol glycoside were the two major compounds identified by high-performance liquid chromatography–diode-array detector in C. laxa, rutin and epigallocatechin were the prominent phenolics present in C. argentea (green variant) while C. argentea (red variant) had epigallocatechin as the most abundant phenolic compound. The extracts showed strong antioxidant actions as revealed by their 2,2-diphenyl-1-picrylhydrazyl radical, 2,2′-azinobis-3-ethylbenzo-thiazoline-6-sulfonate, nitric oxide radical-scavenging abilities and reducing power. These findings indicate that the aqueous extracts from Celosia species are potential sources of natural antioxidants. Practical Application Celosia laxa and Celosia argentea (green and red variants) are green leafy vegetables commonly consumed as food and serve as important ingredients in traditional medicine in Africa and Asia. The assessment of the antioxidant properties, phenolic content and composition of the three Celosia species may give insight into their applications in functional foods and nutraceuticals development.