Anti-tumor Effects of Soybeans and Fermented Soybean Paste

Oral cancer is the sixth most common cancer globally. The effects of several extracts from soybeans and Korean soybean paste (doen-jang) on the growth of human oral carcinoma cells in vitro were assessed. We prepared petroleum ether extract, ethyl acetate extract, chloroform extract, methanol extract, and water extract from soybeans and soybean paste. We used KB cell, which is an oral epidermoid carcinoma cell, and investigated proliferation of the tumor cells using MTT method. Each extract of soybean paste suppressed the KB cell proliferation. A dose-response relationship was observed between the level of ethyl acetate extract of soybean paste and its suppression of the cell proliferation. The effects of soybean extracts were lower than those of soybean paste extracts. The effects might be enhanced by the fermentation of soybeans. The results of this work indicate that extracts from soybeans and Korean soybean paste could have potential as anti-tumor substances.