The combination of genistin and ipriflavone prevents mammary tumorigenesis and modulates lipid profile.

Recent reports have indicated that soy isoflavones may be protective against breast cancer. However, the effects of the synthetic isoflavone, ipriflavone, on mammary tumorigenisis, alone or in combination with genistin, a soy isoflavone, have not been investigated. Eighty-eight 36-day-old female Sprague-Dawley rats were divided as follows: Gen (20 mg genistin/kg body weight), Ipr (200 mg ipriflavone/kg body weight), Gen+Ipr (20/200 mg per kg body weight, respectively), and control (solvent vehicle). A week later, animals were injected with a single dose of methylnitrosourea. The isoflavones and solvent vehicle were administered daily via gastric gavage for 84 days post methylnitrosurea injection. The Gen+Ipr group had the lowest number of palpable tumors and adenocarcinomas per group, the least palpable tumors per rat, and the highest serum total and non-HDL cholesterol levels. No changes in circulating levels of indicators of oxidative stress were detected due to treatment. The findings of this study imply that the combination of genistin and ipriflavone is effective in suppressing mammary methylnitrosurea-induced tumorigenesis and also the lipid environment of the tumor cells that impact tumor growth or proliferation. Further studies are needed to establish the optimal dose of genistin and ipriflavone, individually or in combination, for the prevention of mammary tumorigenesis.