Antioxidant and pro-oxidant properties of acylated pelargonidin derivatives extracted from red radish (Raphanus sativus var. niger, Brassicaceae)

The antioxidant and pro-oxidant potential of an extract from red radish, in which the major compounds were acylated pelargonidin derivatives, were assessed with a variety of assays in vitro. The extract appeared to form a complex with Fe3+ or Cu2+. It displayed a concentration-dependant reducing power (1.16 OD700 nm at a concentration of 4 mM) and scavenging effect against 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radicals (with IC50 = 1.74 ± 0.03 mM). It could promote the cleavage of plasmid DNA with Cu(II)/H2O2 or Cu(II) alone. This DNA damage could be inhibited by horseradish peroxidase, catalase, and EDTA, respectively. The extract also showed growth inhibition of Bel-7402 cells at lower concentration. The results suggested that the formation of reactive oxygen species might be involved in the mechanism of DNA damage. The acylated pelargonidin derivatives extracted from red radish could act as antioxidant and pro-oxidant and their antioxidant and pro-oxidant properties were relative to the reaction conditions. It might provide novel antioxidant and anticarcinogenic agents.