Brown rice and retrograded brown rice alleviate inflammatory response in dextran sulfate sodium (DSS)-induced colitis mice

• Published in: Food & function Vol. 8; no. 12; pp. 4630 - 4643
• Main Authors: Praengam, Kemika, Sahasakul, Yuraporn, Kupradinun, Piengchai, Sakarin, Siriwan, Sanitchua, Wanwisa, Rungsipipat, Anudep, Rattanapinyopituk, Kasem, Angkasekwinai, Pornpimon, Changsri, Khaimuk, Mhuantong, Wuttichai, Tangphatsornruang, Sithichoke, Tuntipopipat, Siriporn
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.01.2017
• Subjects: Animals; Bacteria; Bioactive compounds; Cecum; Cecum - immunology; Cecum - metabolism; Chromans - analysis; Chromans - metabolism; Colitis; Colitis - chemically induced; Colitis - diet therapy; Colitis - immunology; Colitis - metabolism; Colon; Coumaric acid; Cyclooxygenase 2 - genetics; Cyclooxygenase 2 - immunology; Cyclooxygenase-2; Dextran; Dextran sulfate; Dextran Sulfate - adverse effects; Diet; Dietary fiber; Female; Ferulic acid; Humans; Immunoregulation; Inflammation; Inflammatory bowel disease; Inflammatory response; Interferon-gamma - genetics; Interferon-gamma - immunology; Interleukin 6; Interleukin-6 - genetics; Interleukin-6 - immunology; Intestinal microflora; Lymphocytes; Lymphocytes T; Mice; Mice, Inbred C57BL; Microbiota; Nitric-oxide synthase; Oryza - chemistry; Oryza - metabolism; p-Coumaric acid; Phenylpropionates - analysis; Phenylpropionates - metabolism; Powder; Rice; Rodents; Sodium; Starch; Sulfates; Vitamin E - analogs & derivatives; Vitamin E - analysis; Vitamin E - metabolism; γ-Aminobutyric acid
• ISSN: 2042-6496; 2042-650X
• DOI: 10.1039/c7fo00305f

The present study was aimed to investigate the impacts of brown rice (BR) and retrograded brown rice (R-BR) consumption on colonic health and gut microbiota in dextran sulfate sodium (DSS) induced colitis mice. Thirty two female C57Bl/6Mlac mice were fed with modified AIN 93G diets by replacing cornstarch in the original composition with white rice (WR), BR and R-BR powder. The mice were divided into 4 groups and fed with the following experimental diets for 4 weeks: (1) negative control (WR: diet with WR), (2) positive control (DSS_WR: DSS and diet with WR), (3) DSS_BR: DSS and diet with BR, and (4) DSS_R-BR: DSS and diet with R-BR. BR and R-BR had a greater content of fat, dietary fiber, GABA, γ-oryzanol, γ-tocotrienol, ferulic acid and p-coumaric acid than WR (p < 0.05). No significant difference in the level of these bioactive compounds was noted between BR and R-BR. Nevertheless, R-BR had a 1.8 fold resistant starch (RS) content of BR (p < 0.05). The DSS_BR and DSS_R-BR groups showed a lower ratio of colonic weight to length, and a lower content of iNOS, COX-2, MPO, IL-6 and INF-γ in colonic homogenates than the DSS_WR group. However, the DSS treated mice fed with the R-BR diet had significantly milder histopathological inflammatory injury and lower colonic iNOS expression than the DSS_BR and DSS_WR groups. The percentage of mesenteric regulatory T cells significantly increased in the DSS_R-BR group compared to that in the DSS_WR group. The DSS treated mice fed with the R-BR diet showed a significant increase in cecal bacterial diversity and abundance of genera Prevotella, Ruminococcus, Dorea, Coprococcus and Dehalobacterium but a significant decrease in pathogenic bacteria including Bacteroides and Enterococcus compared to the DSS_WR group. Thus, the present data indicate that BR and R-BR ameliorate colonic inflammation in experimental colitis induced by DSS in mice by suppressing inflammatory mediators and modulating regulatory T cell responses as well as bacterial diversity in the cecum.