Pigmented egg yolks are more attractive. Popular culture treats annatto as a powerful anticholesterolemic agent, besides being widely used in the form of industry pigment. This work evaluated the effects of the addition of annatto (Bixa orellana L.) in the feed of hens, verifying a possible alteration of cholesterol in the yolks, content of carotenes, and iron and available iron, over time. One hundred and twenty-five hens divided in control (0% - T1) and four annatto-added treatments (0.5% - T2; 1.0% - T3; 1.5% - T4, and 2.0% - T5) were used. Eggs were collected at 23, 25, 27, 29 and 30 weeks. The animals were randomly separated into five groups of five animals each. The cholesterol was measured by the colorimetric method, vitamin A (β and α carotene) by spectrophotometry, total iron by atomic absorption spectrophotometry, and dialysable iron by dialysis. Tukey's test was used at the 5% level for comparison of the averages. Regarding cholesterol, treatments T2 and T3 did not differ significantly. However, other treatments differed ( P ≤ 0.05) from the control, decreasing the cholesterol level as the percentage of annatto in the feed increased. In time, there was a significant increase ( P ≤ 0.05). For β and α carotene, T5 presented statistically higher values than the others ( P ≤ 0.05). With regard to total iron, T5 had higher values than the others. Dialysable iron was also higher, probably due to the increase in carotenes. Thus, we can conclude that the use of annatto in the feed of layer hens is useful, as it provokes the reduction of cholesterol and promotes an increase in the content of iron and carotenes in eggs.

Naturally occurring antioxidants such as carotenoids are extensively studied for their potential in reducing the risk for cancer and other chronic diseases. In the present study, the radical-scavenger activity of the food additive norbixin, a water-soluble carotenoid extracted from Bixa orellana seeds and commercialized as annatto, was evaluated under conditions of DNA damage induced by reactive oxygen species, particularly by hydroxyl radicals. The cell-free scavenger activity of norbixin was evaluated using plasmid DNA as target molecule and Sn2+ or Fe2+ as oxidant. The addition of H2O2 enhanced DNA breakage induced by metal ions, particularly Fe2+. Under these conditions, norbixin started to protect plasmid DNA against single- and double-strand breakage at a metal:norbixin ratio of 1:1 (Sn2+) and 1:10 (Fe2+). However, at lower ratios to Sn2+, norbixin enhanced Sn2+-induced DNA breakage (P<0.05). The ability of norbixin to protect genomic DNA against oxidative damage was assessed in murine fibroblasts submitted to H2O2-induced oxidative stress and the results were evaluated by the comet assay. Under low serum conditions (2 % fetal bovine serum (FBS)), a protective effect of norbixin against H2O2-induced DNA breakage was inversely related to its concentration, a protection ranging from 41 % (10 μM) TO 21 % (50 μm). At higher concentrations of norbixin, however, oxidative DNA breakage was still enhanced, even in the presence of a high serum concentration (10 % FBS). Under normal conditions, norbixin per se has no detectable genotoxic or cytotoxic effects on murine fibroblasts. The antimutagenic potential of norbixin against oxidative mutagens was also evaluated by the Salmonella typhimurium assay, with a maximum inhibition of 87 % against the mutagenicity induced by H2O2. Although plasmid DNA and Ames data indicated that norbixin can protect DNA against oxidative damage, it seems to be a risky guardian of genomic DNA as it can also increase the extent of oxidative damage.