Antioxidant properties of various solvent extracts from wild ginseng leaves

Water, methanol and ethanol extracts of freeze-dried leaves of wild ginseng were examined for their antioxidant properties. All leaf extracts were capable of free radicals scavenging activity. Among solvent extracts of wild ginseng leaves, ethanol extract showed the highest DPPH, hydroxyl radical scavenging and ferrous ion chelating activity. Otherwise, the highest superoxide radical scavenging activity was found in water extract followed by ethanol and methanol extracts of wild ginseng leaves. Ethanol extracts contained more phenolics (2333.2 mg/100 g) and flavonoids (1199.1 mg/100 g) than other extracts. These differences in concentrations of key antioxidants among various solvent extracts seemed to be responsible for their differences in antioxidant activities. When various solvent extracts were hydrolysed by acid, two aglycons of flavonoid, quercetin and kaempferol, were detected. According to the results obtained from this study, wild ginseng leaves showed marked antioxidant activities due to their abundant antioxidants. (C) 2005 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.