In vitro antioxidant activity of the water and ethanol extracts of Forsythia koreana flowers.

The antioxidant activities of the water and ethanol extracts of F. koreana flowers were evaluated using DPPH, superoxide anion (•O(-2)), and nitric oxide (•NO) radical scavenging activity assays. The SC(50) values of the water extract of F. koreana on DPPH, •O(-2) and •NO were 48.39, 24.36 and 100.21 µg mL(-1), respectively. The SC(50) values of the ethanol extract of F. koreana on the aforesaid free radicals were 57.50, 49.00 and 146.08 µg mL(-1), respectively. Further, the total phenolic contents of both extracts were determined and expressed as milligram gallic acid equivalent (GAE) per gram of extract. The water extract exhibited a higher phenolic content (113.78 mg GAE g(-1)), while the ethanol extract showed 94.53 mg GAE g(-1). Our findings demonstrate that the water and ethanol extracts of F. koreana flowers might be potential natural sources of antioxidative additives for use in the food and other allied industries.