Isothiocyanates and Xenobiotic Detoxification.
Level 5 - mechanism / opinion, no new human data
Narrative review of preclinical mechanisms and selected human biomarker data
PubMed 29288567 · doi:10.1002/mnfr.201700916
What was done
This narrative review synthesizes in vivo animal experiments, in vitro assays in rat and human primary hepatocytes and precision-cut tissue slices, and human observational/biomarker data examining how isothiocyanates (such as phenethyl isothiocyanate, sulforaphane, and erucin) and glucosinolates modulate carcinogen bioactivation and xenobiotic detoxification pathways.
What was found
The abstract reports no numerical values or statistical effect sizes. It describes that isothiocyanates act as mechanism-based inactivators of cytochrome P450 enzymes (notably the CYP1 family), with aromatic phenethyl isothiocyanate showing higher potency than aliphatic forms (sulforaphane, erucin), which require higher doses. Isothiocyanates universally induce phase II detoxification systems, including quinone reductase, glutathione S-transferase, epoxide hydrolase, and UDP-glucuronosyl transferase. In human smokers, phenethyl isothiocyanate increases urinary excretion of inactive mercapturate metabolites of tobacco toxicants.
Why it matters
The review clarifies the dual biochemical mechanisms—inhibition of procarcinogen activation and upregulation of clearance enzymes—underlying the potential chemopreventive properties of cruciferous vegetable compounds.
Limits
The abstract provides no quantitative metrics or formal study inclusion criteria. Much of the underlying evidence derives from in vitro and rodent models at concentrations that may exceed normal dietary exposure. The relative clinical contribution of intact glucosinolate precursors in humans remains unquantified.
Cited by
- supports Consuming leafy greens supports endogenous glutathione production and bodily detoxification.