Modulation of hepatic and intestinal glutathione S-transferases and other antioxidant enzymes by dietary lipids in streptozotocin diabetic rats.

Antioxidant enzymes in liver and small intestine were investigated using control and streptozotocin diabetic rats fed diets with 5% olive, sunflower or fish oil for five weeks. In liver, Glutathione Peroxidase and Superoxide Dismutase decreased and in intestine Glutathione-S-transferase (GST) increased by diabetes. In isolated jejunum and ileum, this increase in GST activity was due to an increase in GST-alpha and -mu isoenzymes in jejunum and GST-alpha, mu and -pi in ileum. Since GST plays an important role in protecting tissues from oxidative damage, our results highlight the role of the intestine against free radicals in physiological or pathological situations.