Taking 120 micromoles of sulforaphane daily for one year reduced the Ki-67 proliferation index by 24% in bronchial tissue of former smokers with a 30 pack-year smoking history.
Mechanism
Synthesis from 1 study
Sulforaphane turns on a cellular cleanup system in the airways that removes harmful chemicals from smoking. This reduces DNA damage, which stops cells from dividing too fast, lowering the number of rapidly dividing cells in the lining of the airways.
Most probable mechanism
Sulforaphane enters cells in the airways and turns on a natural defense system that cleans up harmful chemicals from smoking. This reduces damage to DNA, which stops cells from dividing too quickly.
Sulforaphane is absorbed from the gut and reaches bronchial epithelial cells in sufficient concentration to interact with cellular targets
Sulforaphane modifies specific cysteine residues on the Keap1 protein, causing it to release the Nrf2 transcription factor
Nrf2 moves into the cell nucleus and binds to antioxidant response elements, activating genes that produce detoxifying and antioxidant enzymes
Increased expression of detoxification enzymes reduces levels of reactive oxygen species and DNA adducts caused by tobacco carcinogens
Reduced DNA damage decreases activation of proliferation signaling pathways, leading to lower expression of the Ki-67 protein in bronchial epithelial cells
Evidence from Studies
Supporting (1)
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