The Interactions of Red Clover with Tamoxifen

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Results:

Our results suggest that MCF-7 cells are indeed ERa+, and grow in response to estrogenic signaling (see fig. 1). Because over 70% of breast cancers behave in this way, and are ERa+, MCF-7 cell lines were particularly relevant to our project. Our findings indicate that red clover likely contains phytoestrogens, that have a very similar effect as Estradiol (E2) on MCF-7 cells, by increasing the rate of cell proliferation when applied to the cell line (see fig. 2). This appears to validate the potency of a little studied CAM, which is easily purchased without doctor recommendation or prescription.

The MCF-7 cells were resistant to cell killing by Tamoxifen (Tx) used within our first dose range (as can be observed in fig. 3). It was necessary to increase our doses of Tx, and a greater cell killing effect was achieved (see fig. 4). It was determined that increasing increments of Tx kill increasingly larger amounts of MCF-7 breast cancer cells. Smaller doses of Tx (for example 0.1 – 1.0 mm) showed a small cytostatic effect on MCF-7 cells, while almost all of the MCF-7 cells were killed when treated with 5.0 mm or 10.0 mm of Tx. Cells were also treated with varying increments of Tx as well as 1 nm of E2, which replicated the body of a pre-menopausal woman, and demonstrated the interactions of an estrogen with a SERM. We saw a decrease in the overall MCF-7 cell death when E2 was present, showing that E2 inhibited the effect of Tx. Tx acts as a competitive binding drug, competing with estrogens to attach and disable the ERs. It appears that the presence of E2 decreased the likelihood of Tx binding to the receptors, therefore decreasing the rate at which cells ceased proliferating and dying.

 

Red clover was found to, once again, have an estrogenic effect, and inhibit Tx when applied to MCF-7 cells jointly with Tx. This was the crux of our project, and proved our hypothesis to be true. Red clover decreased the killing effect of Tx when applied with and without E2 (see figs. 5 and 6). The cells with red clover proliferated at a higher rate when treated with Tx, than the cells with only Tx. Between day 10 and 12 a large increase in the total cell number occurred. This could point towards the delayed potency of red clover ( shown in figs. 7 and 8 with error bars).