Preventive effect of fermented brown rice and rice bran on N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis in rats

Abstract

A number of possible preventive agents for cancers in different organs have been reported, however, little information is available regarding the effective agents for the development of gastric cancers. The rice components are known to be effective for the prevention of the development of cancers. Our group has demonstrated that fermented brown rice by Aspergillus Orzae (FBRA) has chemopreventive potentials in several organs. In this study, we investigated the modifying effects of FBRA exposed during the initiation or post-initiation phase of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in rats. Five-weekold male ACI rats were divided into 7 groups. Groups 1-5 were given oral administration of MNNG (100 mg/l in distilled water) for 24 weeks starting at 6 weeks of age. Groups 2 and 3 were fed a diet containing 5 and 10% FBRA during the initiation phase, respectively, whereas groups 4 and 5 were fed these diets during the post-initiation phase. Group 6 was given a diet containing 10% FBRA throughout the experiment. Group 7 was kept on the basal diet alone and served as an untreated control. Rats were sacrificed at 52 weeks after the start, and the epithelium of the stomach was investigated in detail. Incidence and multiplicity of gastric proliferative lesions of group 1 (MNNG alone) were 61% and 1.67±1.57/ rat, respectively. Those of group 5 (25%, 0.35±0.67) which were given FBRA at a dose of 10% during the post-initiation phase were significantly less than those of group 1. Furthermore, the same group expressed a significantly decreased Ki67-labeling index in the non-lesional gastric epithelium when compared to that of group 1. These results indicate that FBRA inhibits MNNG-induced development of gastric tumors by administration during the post-initiation phase in rats. FBRA is regarded as a promising dietary agent for the prevention of human gastric cancer.

Chemopreventive effect of fermented brown rice and rice bran (FBRA) on the inflammation-related colorectal carcinogenesis in ApcMin/+ mice

“…A number of studies have shown the chemopreventive effect of fermented brown rice and rice bran (FBRA) on several types of cancer, including colon cancer (12)(13)(14)(15). In contrast to previous findings that FBRA significantly suppressed azoxymethane-induced colorectal carcinogenesis in rats, in the present study, FBRA has no effect on the tumor development of the colon in Apc Min/+ genetic background.…”

“…Fermented brown rice and rice bran (FBRA) is a processed food prepared by fermented the brown rice and rice bran with Aspergillus oryzae. In our previous studies, FBRA showed chemopreventive effect against various types of chemically-induced cancer, including colon (12), stomach (13), bladder (14) and esophagus (15) …”

Preventive Effect of Actinidia Valvata Dunn Extract on N-methyl-N'-nitro-N-nitrosoguanidine-induced Gastrointestinal Cancer in Rats

“…Groups II and III: treated with 0.1g/L of MNNG with distilled water prepared thrice per week for 24 weeks according to the protocol described in previous reports (Hu et al, 2004;Okazaki et al, 2006;Tomita et al, 2008). The MNNG solution was protected from light and given ad libitum to rats through drinking water.…”

Liposoluble Antioxidative Components in Japanese Traditional Fermented Food "Amazake" Made from Brown Rice

“…BRA has attracted attention as a macrobiotic functional food with possible physiological activity. BRA is an effective chemo preventive agent against inflammation-related gastric [13] and colorectal [14] carcinogenesis, and reduces expression of inflammation-related genes, such as TNF-α, Mac-1, CCL 3, and CXCL 2 [15]. Changes in nutrition during food processing can directly affect the food function, though this has not been sufficiently examined.…”