Analysis of antioxidant activity, total phenol content, and flavonoid content of Abelmoschus manihot flower extracts

Abstract

In this study, we analyzed the antioxidant activity, total phenol, and flavonoid content of Abelmoschus manihot flowers by extracting, concentrating, and freezing the flower site with water and a 70% ethanol solution. The hydrothermal extract (AMW) and the 70% ethanol extract (AME) showed activities of ≥ 77% and ≥ 95% at 100 μg/mL, respectively, in ABTS+ radical scavenging assay. Electron donating availability experiments showed activities of AMW and AME of > 86% and ≥ 91% at 1,000 μg/mL, respectively. In the ferric reducing antioxidant power (FRAP) assay, AME had a reduction force of approximately twice that of AMW at 1,000 μg/mL; moreover AME exhibited reduction force higher than that of AMW. In the SOD-like availability asset, both AMW and AME showed low activities. Total phenol and flavonoid contents were higher in AME than in AMW, although both have similar contents. As a result, AME exhibited higher antioxidant activity than AMW, while their phenol and flavonoid contents were similar. Therefore, A.manihot flower extracts can be considered good natural biological resources for use as raw materials for food and cosmetics.