Preventive Effects of Fermented Brown Rice and Rice Bran on Spontaneous Lymphomagenesis in AKR/NSlc Female Mice

Abstract

Fermented brown rice and rice bran with Aspergillus oryzae (FBRA) is known to possess potentials to prevent<br />chemical carcinogenesis in multiple organs of rodents. In the present study, possible chemopreventive effect of FBRA<br />against spontaneous occurrence of lymphomas was examined using female AKR/NSlc mice. Four-week-old female AKR/<br />NSlc mice were divided into three groups, and fed diets containing FBRA for 26 weeks at a dose level 0% (Group 1), 5%<br />(Group 2) or 10% (Group 3). At the termination of experiment, the incidence of thymic malignant lymphoma of Group<br />3 was significantly lower than of Group 1 (p < 0.05). The average number of apoptotic cells of the thymic lymphoma of<br />Group 3 was significantly larger than that of Group 1 (p < 0.05). In addition, the incidences of malignant lymphoma<br />arising from body surface and abdominal lymph nodes, and the frequencies of lymphoma cell invasion to liver, kidney,<br />spleen, and ovary of Group 3 were relatively lower than those of Group 1. These results indicate that FBRA inhibits<br />spontaneous development of the lymphoma in female AKR/NSc mice and the inhibition of lymphomagenesis may<br />relate to the induction of apoptosis by exposure of FBRA, suggesting that FBRA could be a protective agent against<br />development of human lymphoma.