Radical scavenging activity and antimutagenicity of proanthocyanidins from barley bran

The purpose of this investigation was to clarify the properties of antioxidative activity and antimutagenicity in vitro of proanthocyanidins (dimer and trimer) from barley bran in comparison with catechins. Radical scavenging activities to superoxide and DPPPI radical of the prodelphinidins were found to be higher than those of the procyanidins, and almost the same as those of (-) -epigallocatechin ((-)-EGC) and (-)-epigallocatechin gallate ((-)-EGCG). The prodelphinidins from barley bran showed more effective antimutagenicity to MNNG and Trp-p-1 than that of the procyanidins, and showed the same or less effectiveness than those of (-)-EGCG and (-)-EGC. These results suggested that the B-rings with three hydroxyl groups (pyrogallol-type) such as prodelphinidins, (-)-EGC, and (-)-EGCG were more effective to antioxidative activity and antimutagenicity than the B-rings with two hydroxyl groups (catechol-type) such as procyanidins, (+)-catechin, (-)-epicatechin, and (-)-epicatechin gallate.