In vitro and in vivo antioxidant activities of a flavonoid isolated from celery (Apium graveolens L. var. dulce).

In the present article, a flavonoid was separated and purified from celery leaf through ethanol extraction, column chromatography and crystallization. The product was identified as apiin by LC/ESI-MS, and its antioxidant activities were evaluated in vitro, including by 1,1-diphenl-2-picrylhyrazyl free radical (DPPH˙), superoxide radical (O2(-)˙) and hydroxyl radical (OH˙) scavenging assays. IC50 values were 68.0 μg ml(-1) in the DPPH assay, 0.39 mg ml(-1) in the O2(-)˙ assay and 48.0 μg ml(-1) in the OH˙ assay. The antioxidant activities were investigated in vivo with the use of mice models. All data were measured including the contents of maleic dialdehyde (MDA) and lipofuscin (LPF), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and the total antioxidant capacity (TAOC), in the serum, brain, heart, liver and kidney. Results showed that apiin had a remarkable scavenging activity on MDA and LPF, promoted TAOC and significantly enhanced the activities of SOD, GSH-Px and CAT.