[Influence of selenium-enriched malt on the elevated cGMP concentrations induced by carcinogen]

Rats were fed with selenium-enriched malt containing 1 ppm selenium. As a parameter, cyclic guanosine-3'5'-monophosphate (cGMP) was measured by RIA in the rats following treatment with AFB1. The results demonstrated that the diet containing high selenium inhibited the elevation of cGMP levels in the liver induced by multiple exposures to AFB1 (250 micrograms/kg, 10 times/2 wks), (P < 0.05). Administration of a large single dose of AFB1 (1 mg/kg i.p.) reduced the liver cGMP contents which might be due to injury to the liver. Selenium-enriched diet could prevent this from happening. In high cancer risk areas: the cGMP level in urine of population with higher selenium concentration were lower than that of population with low selenium concentration. A supplementation of 300 micrograms selenium in the form of selenium-enriched malt cakes daily to the subjects with low selenium concentration in blood for one year, the urinary cGMP excretion was significantly decreased from 0.62 mumol/g to 0.49 mumol/g creatinine (P < 0.05). These findings suggest that diet containing high selenium has a protective effect and may play a potential role in cancer chemoprevention.