RT Journal Article SR Electronic T1 Soy Extract Is More Potent than Genistein on Tumor Growth Inhibition JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 2837 OP 2841 VO 28 IS 5A A1 HYEON-A KIM A1 KYU-SHIK JEONG A1 YOO KYEONG KIM YR 2008 UL http://ar.iiarjournals.org/content/28/5A/2837.abstract AB Soybean and soy products have received much attention for their potential heath benefits. Recently it has been reported that the bioactivity of soy products is influenced by the degree of soy processing. This study was conducted to evaluate and compare the influence of diets containing genistein and soy extract on the growth of the estrogen-independent human breast cancer cells, MDA-MB-231, implanted into female Balb/c mice. Four-week-old female athymic nude mice (Balb/c) were acclimatized to an AIN-93G control diet for one week prior to initiating the experimental diets. The animals were placed into three treatment groups, each of which was provided with containing DMSO, genistein (750 μg/g AIN-93G diet) or 0.6% soy extract (containing genistein at 750 μg/g AIN-93G diet) for three weeks from one week prior to the injection of MDA-MB-231 cells (1×106/site) and subsequently fed on the AIN-93G control diet until sacrifice. The tumor volumes increased steeply in the control group and the genistein-treated group. However, tumor growth was significantly reduced in the soy extract-treated group compared to the control and genistein-treated groups. Immunohistochemistry of proliferating cell nuclear antigen (PCNA) also revealed that the soy extract treatment effectively reduced cell proliferation of the implanted tumors. In conclusion, soy extract is more potent than genistein in the inhibition of tumor growth, presumably resulting from the synergistic effect of the various bioactive components in the soy extract.