Dietary dry bean effects on hepatic expression of stress and toxicity-related genes in rats.
Dry bean (Phaseolus vulgaris L.) consumption is associated with reduced risk for a number of chronic diseases. In westernised societies, dry bean consumption is particularly low (approximately 2-4 kg/capita per year) and little information is available about the safety of increasing dietary intake in humans to achieve levels that prevent and control chronic diseases. In anticipation of a human intervention study to address the safety and efficacy of increasing bean consumption, a dose-response study with dietary beans was conducted to establish whether increased bean consumption in rats exhibits changes indicative of hepatic stress or toxicity. Transcript levels from a panel of stress and toxicity-related genes were analysed in female Sprague-Dawley rats fed a dose range of dietary beans that bracketed amounts relevant to human consumption globally. Cooked red bean was incorporated into a purified diet formulation at 0, 7·5, 15, 30 or 60 % w/w for the assessment of adaptive patterns of gene expression using quantitative PCR array. Of the eighty-four genes evaluated, the expressions of Cyp3a11, Cyp7a1, Fmo1, Gstm1, Mif and Ugt1a6 were elevated, whereas the expression of Hspa8 was down-regulated. Liver gene expression was not modulated in a manner indicative of an adverse response. Only the expression of the cholesterol 7α hydoxylase and UDP-glucuronosyltransferase genes increased in a dose-dependent manner at nutritionally relevant dietary bean concentrations. These candidate genes may contribute to the health benefits attributed to increased bean consumption.
Cancer Prevention Laboratory, Colorado State University, 1173 Campus Delivery, Fort Collins, CO              80523, USA.
Erica L
EL
Daniell
Elizabeth P
EP
Ryan
Mark A
MA
Brick
Henry J
HJ
Thompson
D000818:Animals; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics; D004032:Diet / Q000009:adverse effects*; D005260:Female; D057141:Food, Preserved; D015870:Gene Expression; D014453:Glucuronosyltransferase / Q000235:genetics; D006293:Health Promotion; D008099:Liver / Q000378:metabolism*; D027805:Phaseolus / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley; D012639:Seeds / Q000633:toxicity*
C532838:CYP7A1 protein, rat; D002790:Cholesterol 7-alpha-Hydroxylase; D014453:Glucuronosyltransferase; C107611:UDP-glucuronosyltransferase, UGT1A7