Effects of cruciferous allyl nitrile on phase 2 antioxidant and detoxification enzymes

High intake of cruciferous vegetables has been associated with lower risk of various cancers, and the cancer preventive effect of the vegetables has been associated with their high levels of glucosinolates. The hydrolysis of glucosinolates results in the generation of bioactive compounds, including allyl nitrile which we previously found to be an active inducer of some phase 2 enzymes. In this study, we further explored the inductive ability of this nitrile in light of increasing evidence that antioxidants delay or prevent the development of cancer.

Groups of 6 mice were administered subtoxic doses of allyl nitrile (5, 50, 100 or 200 micromol/kg) or vehicle-distilled water daily for 5 days by gastric intubation. On the sixth day, the animals were sacrificed for examination of enzyme activities in their tissues. Enzymes tested were thioredoxin reductase (TR), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase.

Allyl nitrile increased the activity of TR in the liver, kidneys and rectum at doses of 100-200 micromol/kg/day, and GPx in the kidneys and small intestine at 50 to 200 micromol/kg/day, while in the colon, alone, it decreased the activities of GR and catalase at doses of 200 and 100-200 micromol/kg/day, respectively not.

The present results suggest an involvement of allyl nitrile in antioxidant defense in the body, except for the colon.