The clinical trial is a phase 1 multiple dose, safety, pharmacokinetic, and drug interaction study of di-indolyl methane. Since the safety and tolerability of single doses have been determined, the investigators shall administer one of two doses of BR-DIM (based on findings of the first part of the study) to two groups of men and women (each group getting one of the doses). In addition to studying the safety, tolerability and pharmacokinetics of single and multiple doses of BR-DIM, the investigators shall evaluate the effects of BR-DIM on the disposition of a 5-drug probe cocktail. The probe cocktail consists of caffeine (to study CYP1A2), dextromethorphan (CYP2D6), losartan (CYP2C9), buspirone (and endogenous cortisol) for CYP3A4 and fexofenadine, a non-metabolized drug transported by P-glycoprotein. The investigators shall administer these five drugs at three clinic visits: during a placebo run-in, with the first dose of BR-DIM, and again with the last dose after 4 weeks of twice daily BR-DIM. With this design we expect to find out the effects of acute and chronic dosing with BR-DIM on the activities of enzymes involved in metabolism or transport of 95% of clinically used drugs. The investigators shall also examine DIM effects on the phase 2 enzyme, glutathione-S-transferase, and on urinary estrogen metabolites.
