Abstract: The contents of total polyphenols and flavonoids in the seed coats and cotyledons of 10 varieties of broad beans were measured by Folin-Ciocalteu method and sodium nitrite-aluminum chloride method, respectively. Besides, the polyphenolic extracts from seed coats and cotyledons were evaluated for their protective effect on DNA damage induced by peroxy radicals (ROO·). The results showed that the physical parameters of different broad bean varieties such as shape, 100-grain mass, color and density were different. The contents of total polyphenols and flavonoids in the seed coats and cotyledons were in the range of 1.30–2.67 and 0.08–0.23 mg/g, and 2.99–6.56 and 0.26–1.07 mg/g, being higher in the former than in the latter and showing significant differences among the different varieties. The percentage of supercoiled form for DNA treated with the polyphenolic extracts from seed coats and cotyledons ranged from 86.38% to 93.91% and 39.13% to 71.90%, respectively, indicating that the former exhibited higher protective activity against ROO· radical-induced DNA strand breakage than didthe latter.

Key words: broad bean; polyphenols; peroxy radicals; DNA damage; protective activity