Effect of green tea catechins on oxidative DNA damage of hamster
pancreas and liver induced by N-Nitrosobis(2-oxopropyl)amine
and/or oxidized soybean oil
Issue title: The Proceedings of the 3rd International
Conference on Food Factors (ICoFF 03)
Affiliations: Junior College, University of Shizuoka, 2-2-1 Oshika,
Shizuoka, Shizuoka Pref 422-8021, Japan | Redox Regulation Research Group, Tokyo Metropolitan
Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015,
Japan
Abstract: It has been indicated that high fat diet is a risk factor of the
pancreatic cancer by epidemiological studies. We examined whether the oxidized
soybean oil (ox-oil) express the synergistic effect on the formation of
8-oxo-2'-deoxyguanosine (8-oxodG) in nuclear DNA of hamster
pancreas induced by N-Nitrosobis(2-oxopropyl)amine (BOP) and
whether the green tea catechins (GTC) suppressed it. Ox-oil was prepared by air
oxidation, and the content of lipid hydroperoxide was 6.22 mg/ml. Hamsters were
administered 0.3~ml of ox-oil/day orally for 4 weeks before BOP treatment. GTC
was given ad libitum as a 0.1% aqueous solution. Four hours after
subcutaneous administration of BOP, hamsters were sacrificed, and the contents
of 8-oxodG were measured in nuclear DNA of pancreas and liver. The 8-oxodG
content in the pancreas was increased by BOP and/or ox-oil administration.
However, it was not suppressed by an intake of GTC. In the liver, though the
content of 8-oxodG was increased by ox-oil, it tended to suppress the rise of
8-oxodG by a GTC intake. These results suggested that the long term intake of
ox-oil might have the possibility to induce carcinogenesis in hamster pancreas
and liver, and an intake of GTC might have the beneficial effect on liver.
Keywords: oxidative DNA damage, oxidized soybean oil, 8-oxo-2'-deoxyguanosine (8-oxodG), green tea catechins
Journal: BioFactors, vol. 21, no. 1-4, pp. 335-337, 2004
