[Antioxidant properties of a leaf extract from Aronia (Aronia melanocarba) containing proanthocyanidins]

Antioxidant capacity of a procyanidin-containing extract from Aronia melanocarpa leaves has been studied in vitro and in vivo. Using the chemiluminescence technique, the effective content of antioxidants and its reactivity towards peroxyl radicals have been measured in a model reaction of initiated oxidation of hydrocarbon for the whole extract and two of its chromatographic fractions separated by HPLC. The results indicate that the extract contains a combination of antioxidants with different radical scavenging activities. The value of the rate constant of the reaction with peroxyl radicals (constant k7) for the extract strong inhibitors is of the same order of that for alpha-tocopherol and its synthetic analog chroman C. A decrease in antiradical activity directly related to the high concentrations of this extract in reactive mixture has been observed. This extract significantly reduced in dose-dependent fashion the CCl4-induced hepatic lipid peroxidation. The extract also inhibited flaxseed oil peroxidation. The present study indicates significant antioxidant capacity of the extract from Aronia melanocarpa leaves.