Korean J Nutr.  2007 Mar;40(2):138-146.

Oxidative Stress of Mouse Fed with gamma -Irradiated Soybean Diet

• Park SY
• Seo DY
• Suh KS
• Ly SY

Abstract

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades. Harmful contaminants naturally occurred from foods which contain high levels of unsaturated fatty acids that are easily oxidized can affect the human anti-oxidation system through the generation of free radicals. Moreover, previous studies proved that gamma-irradiation may cause production of free radicals in food. We investigated the effect of gamma-irradiated soybeans in relation to oxidative stress in mice. Oxidative index of mice was evaluated by TBARS, DNA fragmentation in various organs such as blood lymphocytes, liver and kidney. Forty male ICR mice were equally divided into 4 groups and fed control diet or gamma-irradiated diet containing 50% soybeans (5, 10, and 20 kGy, respectively )for 8 weeks. Pero-xide values of the irradiated diets were higher than that of the non-irradiated one and increased according to the storage period. There was no significant difference in weight gain as well as in TBARS value in plasma and kidney of all groups. Liver TBARS value of the group fed with irradiated diet at 20 kGy increased significantly compared with the control group (p <0.05 ). DNA oxidative damage as measured by alkaline comet assay showed that % tail DNA in the blood lymphocytes of 5 kGy and 10 kGy groups increased significantly over the control group (p <0.05 ). Also, tail moments of 5 kGy and 10 kGy groups were higher than that of the control group. Ultrastructural examination shows myeline figures and swollen mitochondria in parietal and intestinal epithelial cells of the group fed with irradiated diet. Therefore, considering unsaturated fatty acid content, consumption of soybeans gamma-irradiated with over 20 kGy or repe-atedly may decrease the body's antioxidant mechanism.

Keyword

gamma irradiation; DNA damage; alkaline comet assay; cell damage

MeSH Terms

Animals
Comet Assay
Diet*
DNA
DNA Damage
DNA Fragmentation
Epithelial Cells
Fatty Acids, Unsaturated
Food Irradiation
Free Radicals
Humans
Kidney
Liver
Lymphocytes
Male
Mice*
Mice, Inbred ICR
Mitochondria
Myelin Sheath
Oxidative Stress*
Plasma
Rabeprazole
Soybeans*
Thiobarbituric Acid Reactive Substances
Weight Gain
DNA
Fatty Acids, Unsaturated
Free Radicals
Thiobarbituric Acid Reactive Substances