Inhibition by Long-term Fermented Miso of Induction of Pulmonary Adenocarcinoma by Diisopropanolnitrosamine in Wistar Rats

The present study was designed to investigate the effects of fermented miso in the diet on the development of lung tumors initiated by diisopropanolnitrosamine (BHP) in male Slc:Wistar rats. A total of 63 animals, 6 weeks of age, were divided into 4 groups and given BHP (2000 ppm) in their drinking water for 10 weeks. After the carcinogen treatment the rats were fed a normal control MF solid diet, or the same diet containing 100ng-term or short-term fermented miso for 12 weeks. The long-term fermented miso significantly reduced the number of lung tumors, adenocarcinomas and PCNA strongly positive tumors as compared with the short-term fermented miso. The present results thus indicate that dietary supplementation with long-term fermented miso could exert chemopreventive effects on lung carcinogenesis.