Cytotoxicity of coffee in human intestinal cells in vitro and its inhibition by peroxidase.
The cytotoxic effects of dried preparations of nine different beverages, including alcoholic drinks, on human embryonic intestinal cells in vitro and the cytoprotective effects of several enzymes were examined. Instant coffee and green tea were the most cytotoxic beverages (ID(50) value 0.016 ml equivalents/ml). Peroxidase (0.015 units/ml) completely nullified the cytotoxic effects of instant coffee, green tea and black tea; catalase had a less protective effect. In contrast, superoxide dismutase, which increased the amount of hydrogen peroxide in coffee solution, enhanced the cytotoxicity of coffee. The cytoprotective effects of peroxidase and catalase seem, therefore, to be due, at least in part, to their decomposition of hydroperoxides such as hydrogen peroxide in beverages.
Itagaki
S K
SK
Health Science Laboratory, Institute for Biomedical Research Suntory Ltd, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618, Japan.
Kobayashi
T
T
Kitagawa
Y
Y
Iwata
S
S
Suwa
Y
Y
Nukaya
H
H
Tsuji
K
K