Transcriptome analysis provides new insights into liver changes induced in the rat upon dietary administration of the food additives butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole.
Transcriptomics was performed to gain insight into mechanisms of food additives butylated hydroxytoluene (BHT), curcumin (CC), propyl gallate (PG), and thiabendazole (TB), additives for which interactions in the liver can not be excluded. Additives were administered in diets for 28 days to Sprague-Dawley rats and cDNA microarray experiments were performed on hepatic RNA. BHT induced changes in the expression of 10 genes, including phase I (CYP2B1/2; CYP3A9; CYP2C6) and phase II metabolism (GST mu2). The CYP2B1/2 and GST expression findings were confirmed by real time RT-PCR, western blotting, and increased GST activity towards DCNB. CC altered the expression of 12 genes. Three out of these were related to peroxisomes (phytanoyl-CoA dioxygenase, enoyl-CoA hydratase; CYP4A3). Increased cyanide insensitive palmitoyl-CoA oxidation was observed, suggesting that CC is a weak peroxisome proliferator. TB changed the expression of 12 genes, including CYP1A2. In line, CYP1A2 protein expression was increased. The expression level of five genes, associated with p53 was found to change upon TB treatment, including p53 itself, GADD45alpha, DN-7, protein kinase C beta and serum albumin. These array experiments led to the novel finding that TB is capable of inducing p53 at the protein level, at least at the highest dose levels employed above the current NOAEL. The expression of eight genes changed upon PG administration. This study shows the value of gene expression profiling in food toxicology in terms of generating novel hypotheses on the mechanisms of action of food additives in relation to pathology.
TNO Quality of Life, Business Unit Biosciences, P.O. Box 360, 3700 AJ Zeist, The Netherlands. rob.stierum@tno.nl
Rob
R
Stierum
Ana
A
Conesa
Wilbert
W
Heijne
Ben van
Bv
Ommen
Karin
K
Junker
Mary P
MP
Scott
Roger J
RJ
Price
Clive
C
Meredith
Brian G
BG
Lake
John
J
Groten
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002084:Butylated Hydroxytoluene / Q000633:toxicity; D003474:Curcumin / Q000633:toxicity; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism; D019362:Cytochrome P-450 CYP2B1 / Q000378:metabolism; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D003627:Data Interpretation, Statistical; D004032:Diet; D005503:Food Additives / Q000633:toxicity*; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000187:drug effects*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010084:Oxidation-Reduction; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D011435:Propyl Gallate / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013250:Steroid Hydroxylases / Q000378:metabolism; D013827:Thiabendazole / Q000633:toxicity
D018076:DNA, Complementary; D005503:Food Additives; D010171:Palmitoyl Coenzyme A; D002084:Butylated Hydroxytoluene; D011435:Propyl Gallate; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; D019388:Cytochrome P-450 CYP1A2; D019362:Cytochrome P-450 CYP2B1; C025619:steroid 16-beta-hydroxylase; D005982:Glutathione Transferase; D003474:Curcumin; D013827:Thiabendazole