Hepatic cytochrome P450 and UDP-glucuronosyl transferase are affected by five sources of dietary fiber in germ-free rats.
The influence of dietary fiber on xenobiotic-metabolizing enzymes (XME) was assessed using germ-free rats fed inulin and other sources of fiber (wheat bran, carrot, cocoa and oat). The consumption of cocoa fiber greatly modified the hepatic cytochrome P450 isoenzymatic profile, causing a strong enhancement of 1A2 and 2B1/B2 forms, concomitant with a significant decrease of the constitutive form 2C11, compared with all of the other types of fiber. Moreover, rats fed the cocoa fiber diet had a higher specific activity of hepatic UDP-glucuronosyl transferase than their carrot fiber- and wheat bran-fed counterparts. Intestinal UDP-glucuronosyl transferase was unaffected by the type of ingested fiber. Diet composition also did not alter the specific activity of glutathione-S-transferase in the liver, small intestine, or colon. Using earlier results obtained in heteroxenic rats, we show that intestinal microflora plays a key role in some of the effects of fiber on XME, although this is not a necessary prerequisite for all of the liver alterations.
Nugon-Baudon
L
L
INRA, Unité d'Ecologie et Physiologie du Système Digestif, Jouy-en-Josas, France.
Roland
N
N
Flinois
J P
JP
Beaune
P
P
D000704:Analysis of Variance; D000818:Animals; D018554:Avena / Q000737:chemistry; D002099:Cacao / Q000737:chemistry; D003106:Colon / Q000187:drug effects / Q000201:enzymology; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis* / Q000378:metabolism; D018552:Daucus carota / Q000737:chemistry; D004043:Dietary Fiber / Q000032:analysis / Q000494:pharmacology*; D005856:Germ-Free Life; D014453:Glucuronosyltransferase / Q000032:analysis* / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000201:enzymology; D007444:Inulin / Q000494:pharmacology; D007527:Isoenzymes; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D014908:Triticum / Q000737:chemistry
D004043:Dietary Fiber; D007527:Isoenzymes; D007444:Inulin; D003577:Cytochrome P-450 Enzyme System; D014453:Glucuronosyltransferase