Selenium‐enriched Japanese Radish Sprouts Influence Glutathione Peroxidase and Glutathione S‐Transferase in an Organ‐specific Manner in Rats

Abstract

Selenium-enriched Japanese radish sprouts (Se-enriched JRS), in which Se-methylselenocysteine accounted for 80% of Se compounds, inhibited mammary tumorigenesis induced by 7,12-dimethylbenz[a]anthracene in rats. The effects of Se-enriched JRS on the oxidative stress-scavenging enzymes were investigated in rats. F344 female rats were fed test diets, in which Se-enriched JRS was added at 0, 2.4, 5.0, 8.8 or 12.5 ppm Se to commercial rodent chow for 3 wk. Glutathione peroxidase (GPx) and glutathione S-transferase (GST) in rat livers, kidneys and lungs were measured. Tissue Se concentrations at the highest Se dose (12.5 ppm) were high in order as follows: kidney > liver > lung. The diet at 12.5 ppm Se reduced the increase in body weight and, conversely, increased the liver weight. The Se test diets decreased hepatic and renal GPx activity at more than 2.4 ppm and 5.0 ppm, respectively. In contrast, the test diets increased pulmonary GPx activity at more than 2.4 ppm Se. The diets increased hepatic GST activity at more than 2.4 ppm Se dose dependently, whereas they reduced pulmonary GST activity at more than 2.4 ppm. The diet of 12.5 ppm Se induced GST Yp in all 3 organs and GST Yb1 in the liver. Thus, Se-enriched JRS influenced GPx and GST activity in a symmetrical manner in the livers and lungs of rats, with hepatic GST possibly affected, in part, by the induction of GST Yb1.