6β-hydroxy Testosterone

CYP3A4 and CYP3A5 are cytochrome P450 enzymes whose expression is induced by glucocorticoids and certain xenobiotics, including many drugs and chemical carcinogens.1 They mediate the metabolism of xenobiotics as well as certain endobiotics, including steroid hormones.2

6β-hydroxy Testosterone is a major metabolite produced from testosterone by the actions of CYP3A4 and CYP3A5, accounting for 75-80% of all metabolites formed from testosterone.2,3 The biological effects of 6β-hydroxy testosterone have been poorly studied.

Reference:
1. Cooper, B.W., Cho, T.M., Thompson, P.M., et al. Phthalate induction of CYP3A4 is dependent on glucocorticoid regulation of PXR expression Toxicological Sciences 103(2), 268-277 (2008).
2. Draper, A.J., Madan, A., Smith, K., et al. Development of a non-high pressure liquid chromatography assay to determine testosterone hydroxylase (CYP3A) activity in human liver microsomes Drug Metabolism and Disposition 26(4), 299-304 (1998).
3. Capdevila, J.H., Karara, A., Waxman, D.J., et al. Cytochrome P-450 enzyme-specific control of the regio- and enantiofacial selectivity of the microsomal arachidonic acid epoxygenase The Journal of Biological Chemisty 265, 10865-10871 (1990).