title: Antigenotoxic and antimutagenic potential of an annatto pigment (norbixin) against oxidative stress.
abstract: Carotenoids are 40-carbon molecules with conjugated double bonds, making them particularly effective for quenching free radicals. They have always been believed to possess anticancer properties, which could be due to their antioxidant potential. Norbixin is an unusual dicarboxylic water-soluble carotenoid present as a component in the pericarp of the seeds of Bixa orellana L. (from the Bixaceae family), a tropical shrub commonly found in Brazil. The main carotenoids present in these seeds, bixin and norbixin, form a coloring material, known as annatto, which is mainly used in the food industry. As annatto is only used as a coloring material, most studies of annatto pigments have focused on the determination of annatto levels in food. However, little attention has been given to the biological properties of bixin and norbixin. We evaluated the effect of norbixin on the response of Escherichia coli cells to DNA damage induced by UV radiation, hydrogen peroxide (H2O2) and superoxide anions (O2*-)) and found that norbixin protects the cells against these agents. Norbixin enhanced survival at least 10 times. The SOS induction by UVC was inhibited 2.3 times more when cells were grown in the presence of norbixin. We also found that norbixin has antimutagenic properties, with a maximum inhibition of H2O2-induced mutagenic activity of 87%, based on the Salmonella mutagenicity test.
authors.affiliation: Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro 87, fundos, 4o. andar, 20551-030 Rio de Janeiro, RJ, Brazil.
authors.forename: Antonio C T S
authors.initials: AC
authors.lastname: Júnior
authors.forename: Lídia M B O
authors.initials: LM
authors.lastname: Asad
authors.forename: Eduardo B de
authors.initials: EB
authors.lastname: Oliveira
authors.forename: Karla
authors.initials: K
authors.lastname: Kovary
authors.forename: Nasser R
authors.initials: NR
authors.lastname: Asad
authors.forename: Israel
authors.initials: I
authors.lastname: Felzenszwalb
mesh_terms: D016587:Antimutagenic Agents / Q000494:pharmacology*; D031212:Bixaceae / Q000737:chemistry; D002338:Carotenoids / Q000494:pharmacology*; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects; D004269:DNA, Bacterial / Q000187:drug effects / Q000528:radiation effects; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000633:toxicity; D009152:Mutagenicity Tests / Q000379:methods; D018384:Oxidative Stress / Q000187:drug effects*; D013014:SOS Response, Genetics; D013481:Superoxides / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D016587:Antimutagenic Agents; D004269:DNA, Bacterial; D013481:Superoxides; D002338:Carotenoids; D006861:Hydrogen Peroxide; C099823:norbixin