title: Effect of bixin and norbixin on the expression of cytochrome P450 in HepG2 cell line.
abstract: Bixin and norbixin are the main components of annatto, which is extracted from Bixa orellana and largely used as natural colorant in the food and pharmaceutical industries. Annatto can enhance CYP1A and CYP2B activity in rats; however, the inducer effect has not been investigated in human cell lines. In this study, the ability of bixin and norbixin to induce the cytochrome P450 (CYP) enzymes was assessed in HepG2 human hepatoma cell line. HepG2 cells were treated with bixin and norbixin, and the expression of the CYP genes quantified by real-time reverse transcription polymerase chain reaction (RT-PCR). Expression of CYP1A1 and CYP1A2 was significantly increased by bixin treatment, while CYP2B6, 2C9, 2E1 and 3A4 were unaffected. Cells were treated with norbixin showed no inducer effect. The results suggest that the inducer potential of annatto is attributed to bixin, but not to norbixin, despite their similarities in molecular structure.
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Pharmacy, University of São Paulo, Av. Prof. Lineu Prestes, 580-Bloco 13 A, São Paulo, 05508-900, SP, Brazil. miriamcs@usp.br
authors.forename: Míriam Cristina Sakuragui
authors.initials: MC
authors.lastname: Matuo
authors.forename: Rafael Teruiti
authors.initials: RT
authors.lastname: de Oliveira Takamoto
authors.forename: Irene Satiko
authors.initials: IS
authors.lastname: Kikuchi
authors.forename: Terezinha
authors.initials: T
authors.lastname: de Jesus Andreoli Pinto
mesh_terms: D002338:Carotenoids / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects*; D056945:Hep G2 Cells; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002338:Carotenoids; D003577:Cytochrome P-450 Enzyme System; C004588:bixin; C099823:norbixin
keywords: HepG2; bixin; cytochrome P450 induction; gene expression; norbixin