title: Resveratrol affects CYP1A expression in rainbow trout hepatocytes.
abstract: Resveratrol (RVT), a polyphenolic phytoalexin found in a variety of food products, including grapes and peanuts, is a well-characterized aryl hydrocarbon receptor (AhR) antagonist in mammalian cell lines. The lack of a reliable tool to block AhR signaling in rainbow trout (Oncorhynchus mykiss) prompted this study to evaluate the utility of RVT as an AhR antagonist in a piscine system. Trout hepatocytes in primary culture were exposed to varying doses of RVT (10(-5)-10(-12) M) either in the presence or absence of a well-established AhR agonist, beta-naphthoflavone (BNF). Indeed, BNF significantly elevated CYP1A and AhR protein expression in trout hepatocytes, and this response was inhibited at high (10(-5)-10(-7) M), but not low (10(-8)-10(-10) M), RVT doses. However, RVT alone at low doses (10(-8)-10(-10) M) significantly elevated CYP1A protein expression compared to control hepatocytes. This higher protein response with RVT was completely abolished with actinomycin D and cycloheximide suggesting transcriptional and translational regulation of CYP1A induction. Also, RVT at low (10(-9) M), but not high (10(-5) M), dose significantly elevated CYP1A1 mRNA transcript levels in BNF-primed hepatocytes supporting transcriptional modulation. Taken together, RVT is an effective AhR antagonist, but induces CYP1A expression at lower doses (<10(-8) M) in trout hepatocytes.
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ont., Canada, N2L 3G1.
authors.forename: Neelakanteswar
authors.initials: N
authors.lastname: Aluru
authors.forename: Mathilakath M
authors.initials: MM
authors.lastname: Vijayan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis / Q000187:drug effects*; D017931:DNA Primers / Q000737:chemistry; D003609:Dactinomycin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology; D017686:Oncorhynchus mykiss / Q000502:physiology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D000077185:Resveratrol; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013267:Stilbenes / Q000494:pharmacology*; D019324:beta-Naphthoflavone / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D004791:Enzyme Inhibitors; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D013267:Stilbenes; D003609:Dactinomycin; D019324:beta-Naphthoflavone; D003513:Cycloheximide; D019363:Cytochrome P-450 CYP1A1; D000077185:Resveratrol