Breast Chemoprotection - DIM exert a variety of biochemical effects including the induction of phase I and phase II enzymes that detoxify carcinogenic estrogens.  Administration of either I3C or DIM results in increased 2-hydroxylation of estrogens.

The endogenous estrogen 17beta-estradiol can be metabolized to 16alpha-hydroxyestrone (16alpha OHE1) or 2-hydroxyestrone (2OHE1). In contrast to 2OHE1, 16alpha OHE1 is highly estrogenic and has been found to enhance the proliferation of estrogen-sensitive breast cancer cells in culture. It has been hypothesized that shifting the metabolism of 17beta-estradiol toward 2OHE1 and away from 16alphaOHE1 could decrease the risk of estrogen-sensitive cancers, such as breast cancer. In a small clinical trial, increasing cruciferous vegetable intake of healthy postmenopausal women for four weeks increased urinary 2OHE1:16alpha OHE1ratios, suggesting that high intakes of cruciferous vegetables can shift estrogen metabolism.

DIM inhibited endogenous PSA transcription and reduced DHT-induced intracellular and secreted PSA protein levels in LNCaP human androgen-dependent prostate cancer cells.