Background: Phenethyl isothiocyanate (PEITC), the most comprehensively studied aromatic isothiocyanate,has been shown to act as an anti-cancer agent mainly through modulation of biotransformation enzymesresponsible for metabolizing carcinogens in the human body. Humans are often exposed to carcinogenic factors,some of which through the diet, such as polycyclic aromatic hydrocarbon benzo[a]pyrene via the consumptionof over-cooked meats. Inhibition of the enzymes responsible for the bioactivation of this carcinogen, for exampleCYP1A1, the major enzyme required for polycyclic aromatic hydrocarbons (PAHs) bioactivation, is recognizedas a chemoprevention strategy.
Objective: To evaluate the inhibitory effects of PEITC against benzo[a]pyreneinducedrise in rat liver CYP1A1 mRNA and apoprotein levels. Materials and
Methods: Precision cut rat liverslices were treated with benzo[a]pyrene at 1 and 5 μM in the presence of PEITC (1-25 μM) for 24 hours, followedby determination of CYP1A1 mRNA and apoprotein levels using quantitative polymerase chain reaction andimmunoblotting.
Results: Findings revealed that PEITC inhibited benzo[a]pyrene-induced rise in rat liverCYP1A1 mRNA in a dose-dependent manner as well as the apoprotein levels of CYP1A.
Conclusions: It wasdemonstrated that PEITC can directly inhibit the bioactivation of benzo[a]pyrene, indicating chemopreventivepotential.