Background: Steroids are groups of biologically active molecules with a wide variety of physiological and pharmacological functions. Human cytochrome P450 (CYP) enzymes present in probably every tissue are found responsible for biosynthesis and catabolism of steroids, which could result in either active or inactive metabolites. In addition, exposure to endogenous and exogenous steroids that causes modulation of CYP activities may substantially affect the pharmacokinetic behavior of a given drug.
Objective: This article summarizes our current understanding of the ability of steroids to act as substrates, inhibitors or heteroactivators for human CYP enzymes, with a specific focus on their functional consequences.
Methods: In the current review, we compare the mechanisms and regulation of CYP-mediated biotransformation of steroids, and in particular examine the diverse tissue distributions and biological roles of individual CYPs.
Conclusion: Metabolic instability of steroids in the presence of CYPs not only affects the magnitude and duration of their actions but may also alter the profiles of their physiological, pathological, pharmacological and toxicological effects in relevant organs.