Sulforaphane decreases the levels and function of the liver enzyme cytochrome P450 3A4 by blocking the receptor that activates this enzyme when the body encounters foreign substances.
Mechanism
Synthesis from 1 study
Sulforaphane locks a liver switch that normally turns on a drug-breaking enzyme. When the switch is locked off, the enzyme isn't made, so the liver can't break down drugs as quickly.
Most probable mechanism
Sulforaphane binds to a liver receptor that normally turns on a drug-processing enzyme, preventing the receptor from activating the gene for that enzyme. Without activation, the enzyme is not made in large amounts, so the liver breaks down fewer drugs.
Sulforaphane binds directly to the ligand-binding domain of the steroid and xenobiotic receptor (SXR/hPXR)
Binding of sulforaphane prevents recruitment of coactivator proteins required for transcriptional activation
Inhibition of SXR/hPXR transcriptional activity reduces expression of the CYP3A4 gene
Reduced CYP3A4 gene expression leads to lower levels of CYP3A4 enzyme protein
Lower CYP3A4 enzyme levels decrease the catalytic clearance of its substrate molecules
Evidence from Studies
Supporting (1)
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The Dietary Isothiocyanate Sulforaphane Is an Antagonist of the Human Steroid and Xenobiotic Nuclear Receptor
Contradicting (0)
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Gold Standard Evidence Needed
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