Antioxidant properties of various solvent extracts from lychee (Litchi chinenesis Sonn.) flowers

The antioxidant capacities of the acetone, methanol and water extracts of hot-air dried lychee (Litchi chinenesis Sonn.) flowers were estimated with Trolox equivalent antioxidant capacity (TEAC) assay, reducing power and 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical-scavenging assay. The contents of antioxidant components in these extracts were also determined. Results showed that the highest and lowest contents of these components including phenols, flavonoids and condensed tannins were found in acetone and water extracts, respectively. The antioxidant activities of the lychee flower extracts for all assays were in the order: acetone extract > methanol extract > water extract. The contents of antioxidant components in these extracts were correlated with antioxidant activities.