Antitumor Cell Proliferation and Antigenotoxic Effects of Sufu and Koji Granule, the Chinese Traditional Fermented Product of Soybeans

摘要

Sufu is traditional Chinese fermented product of soybean. In the present study, sufu was manufactured by ripening salted tofu cubes in Aspergillus oryzae-fermented rice-soybean koji mash at 37°C for a period of 16 days. The methanol extracts of the non-fermented tofu cubes, sufu, and koji granules collected at various ripening periods were examined for their antiproliferative effect against human colon cancer cells, Caco-2 and HT-29, as well as their suppression effect against the genotoxicity of 4-nitroquinoline-N-oxide (4-NQO) on Intestine-470 cells. It was generally found that the extracts of tofu cubes and koji granules exhibited an antiproliferative effect against the cancer cells in a dose-dependent manner. However, greater antiproliferative activity was noted with the extracts of the ripened sufu and koji granules. Moreover, the antiproliferative effect against cancer cells increased during the ripening period. The investigation of the suppression effect against genotoxicity revealed that the extracts of tofu cubes and koji granules before ripening showed no protective effect on Int-470 against the genotoxicity of 4-NQO, yet the extracts of the ripened sufu and koji granules did exhibit antigenotoxicity against 4-NQO. This antigenotoxicity increased during the ripening period.