Cruciferous vegetables contain sulforaphane, and sulforaphane triggers the activation of cellular pathways that defend against oxidative stress.
Mechanism
Synthesis from 4 studies
Sulforaphane from cruciferous vegetables turns on a cellular switch that activates genes making protective enzymes. These enzymes clean up harmful chemicals and repair damaged molecules, preventing cells from growing abnormally.
Most probable mechanism
Sulforaphane enters cells and binds to a protein that normally blocks a master regulator of defense genes. This binding frees the regulator, allowing it to move into the cell's control center and turn on genes that make enzymes to neutralize harmful chemicals and repair damaged molecules.
Sulforaphane is absorbed from the digestive tract and distributed to target tissues including bronchial epithelium and hepatocytes
Sulforaphane modifies specific cysteine residues on the Keap1 protein, disrupting its binding to Nrf2
Nrf2 escapes degradation and translocates into the nucleus
Nrf2 binds to antioxidant response elements in the DNA, initiating transcription of cytoprotective genes including NQO1 and HO-1
Increased expression of phase II detoxification and antioxidant enzymes reduces oxidative stress and DNA damage
Reduced oxidative DNA damage suppresses abnormal cell proliferation in epithelial tissues
Less supported by current evidence, but not ruled out
Sulforaphane binds to a nuclear receptor that controls the production of enzymes that break down toxins, preventing the receptor from activating those enzymes and reducing the breakdown of harmful substances.
Sulforaphane binds directly to the ligand-binding domain of SXR/PXR
Binding prevents recruitment of coactivator proteins required for transcriptional activation
Transcription of the CYP3A4 gene is suppressed
CYP3A4 enzyme levels decrease, reducing the metabolic clearance of xenobiotic substrates
Evidence from Studies
Supporting (4)
Community contributions welcome
Optimal dietary patterns for healthy aging
The Dietary Isothiocyanate Sulforaphane Is an Antagonist of the Human Steroid and Xenobiotic Nuclear Receptor
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
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