title: Effect of annatto on micronuclei induction by direct and indirect mutagens in HepG2 cells.
abstract: Annatto (AN), a natural food colorant rich in carotenoids, has been reported as being an effective antioxidant, but little is known about its potential chemopreventive properties. In this study, we evaluated the ability of AN to protect human hepatoma cells (HepG2) from micronucleus (MN) induction against three different mutagens: benzo(a)pyrene (B(a)P), doxorubicin (DXR), and methyl methanesulfonate (MMS). In an attempt to clarify the possible mechanism of antimutagenicity of AN, three protocols of treatment were applied (pretreatment; simultaneous treatment, and post-treatment with AN following treatment with the mutagens). Also, cells exposed only to AN were assayed for cytotoxicity and mutagenicity. A dosage up to 10 microg/ml of AN was devoid of mutagenic activity. Protective effects were seen on micronuclei induced by B(a)P and DXR using pre and simultaneous treatment, but AN had no significant effect on MN induction by MMS in any of the protocols. Our results also show that exposure of cells to concentrations of AN higher than 10 microg/ml decreased cell viability. Taken together, our findings indicate that AN presents antimutagenic activity in vitro, but its protective effect is dependent on the mutagen and on type of treatment suggesting its potential use as a chemopreventive agent.
authors.affiliation: Departamento de Análises Clínicas, Bromatológicas e Toxicológicas de Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo Av. do Café, s/n., Campus Universitário da USP, Ribeirão Preto, SP, 14040-903, Ribeirão Preto, São Paulo, Brasil. barcelos@fcfrp.usp.br
authors.forename: Gustavo Rafael Mazzaron
authors.initials: GR
authors.lastname: Barcelos
authors.forename: José Pedro Friedmann
authors.initials: JP
authors.lastname: Angeli
authors.forename: Juliana Mara
authors.initials: JM
authors.lastname: Serpeloni
authors.forename: Bruno Alves
authors.initials: BA
authors.lastname: Rocha
authors.forename: Mário Sérgio
authors.initials: MS
authors.lastname: Mantovani
authors.forename: Lusânia Maria Greggi
authors.initials: LM
authors.lastname: Antunes
mesh_terms: D001564:Benzo(a)pyrene / Q000633:toxicity; D031212:Bixaceae / Q000633:toxicity*; D002338:Carotenoids / Q000633:toxicity*; D002460:Cell Line; D004317:Doxorubicin / Q000633:toxicity; D006801:Humans; D008741:Methyl Methanesulfonate / Q000633:toxicity; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D010936:Plant Extracts / Q000633:toxicity*
chemical_list: D009153:Mutagens; D010936:Plant Extracts; D001564:Benzo(a)pyrene; D002338:Carotenoids; C054041:annatto; D004317:Doxorubicin; D008741:Methyl Methanesulfonate