• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.278-284
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• 2006

The beneficial effects of digested onion extracts have been assessed by antimutagenic and anticancer activities by Ames test and SRB test. The total phenolic acids and flavonoids in onion extracts were determined. Red and yellow onions contain more phenolic acids and flavonoids than those in the white onion. Digested, extracts showed antimutagenic activity and anticancer activity, and it appears that the antimutagenic activity of digested extracts of onion against mutagens and anticancer activities were related to their phenols and flavonoids contents. Moreover, the extracts inhibited the proliferation of four human tumorigenic cell lines such as HT-29 (colon), MCF-7 (breast), DU-145 (prostate) and HepG2 (liver), in a dose-dependent manner. Phenolic acids and flavonoids caused oxidative damage to the cancer cell lines and induced apoptosis. Generally, red onion extracts showed effective antimutagenic and anticancer activity, and the digested red onion extracts elicited stronger antimutagenic activity than those of the onion extracts without digestion.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.925-930
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• 2004

Antioxidant activity and antimutagenic activities with and without simulated gastric digestion of hot water extracts from white and yellow onions were investigated as compared to BHT and ascorbic acid as control Contents of total phenol and flavonoid in hot water extract of yellow onion were higher than those of white one. The scavenging activity of hydrogen peroxide of both extracts were increased in direct proportion to added their concentration. Antioxidant activity and reducing power of the hot water extract were elevated through analysis of $\beta-carotene-linoleate$ system and were lower than those of BHT and ascorbic acid. Antimutagenic activity after simulated gastric digestion of hot water extract of white and yellow onions was observed against mutagen IG and MNNG on Salmonella typhimurium TA80 and TA100. Extract of yellow onion was higher in antimutagenic activity than that of white one. In conclusion, these results suggested that phenol and flavonoid in hot water extract from yellow and white onions may play an important role in the antioxidant and antimutagenic activities.