Mechanistic studies have suggested that antioxidants have beneficial effects on age-related macular degeneration (AMD). This study aimed to investigate the association between the types and sources of dietary vitamin and carotenoid intakes and AMD risk in China. A matched case–control study of 260 AMD cases and 260 matched controls was performed. The participants were interviewed for dietary information and potential confounders, and comprehensive ophthalmic examinations were performed. Conditional logistic models were used to estimate the odds ratio (OR) and 95 % confidence interval (CI) of specific vitamins and carotenoids and their main sources. When comparing the extreme quartiles, the ORs (95 % CI) were 0·30 (0·10, 0·88) for lutein and 0·28 (0·11, 0·74) for β-cryptoxanthin. The associations for other dietary vitamin and carotenoid intakes were generally weaker and non-significant. Higher intakes of spinach and egg, which are important sources of lutein, were associated with a reduced odds of AMD. ORs (95% CIs) comparing extreme categories were 0·42 (0·20, 0·88) for spinach and 0·52 (95% CI: 0·27, 0·98) for egg. Participants who were in the highest category of both egg intake and spinach intake had a much greater reduced odds of having AMD (OR: 0·23; 95% CI: 0·08, 0·71) than those in the lowest category of egg intake and spinach intake. In conclusion, a higher intake of lutein and lutein-rich foods was associated with a significantly decreased odds of AMD. These findings provide further evidence of the benefits of lutein and lutein-rich foods in the prevention of AMD.

In this study, polyploidy level was determined by flow cytometry analysis. The effect of polyploidy by colchicine treatment was examined on the growth parameters, malondealdehyde (MDA), as well as activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in response to different levels of salinity in Dunaliella salina. The results of algal growth indicated that 3 M NaCl was the optimal concentration of salt, since the highest enhancement in fresh and dry weight, chlorophyll and carotenoids, soluble sugar, glycerol, protein and starch content was observed in comparison to other concentrations. The amount of these metabolites declined in the concentrations under optimum salinity. The least and highest amounts of MDA were observed at 1 and 4 M NaCl respectively. Polyploidy in optimum concentration of salt, caused further increment of the above growth parameters. In relation to this, in most cases, treatment of 0.1% colchicine was most effective. The beneficial effects of polyploidy in non-optimal conditions were also found in some parameters such as biomass, chlorophyll, carotenoids, proteins and starch. Furthermore, the activity of antioxidant enzymes CAT, SOD and POD showed a positive significant correlation with salt stress and these were maximized at 4 M NaCl. Polyploidy (especially colchicine 0.1%) affected activity of these antioxidant enzymes in some concentrations of salt. Overall, our results suggest that the microalgae has significantly different responses to salt stress based on ploidy levels.

Chlorophyll content of wheat (Triticum aestivum L. ‘Mericopa’) and corn (Zea mays L. ‘Merit’) treated with the herbicide fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)-phenyl]-4(1H)-pyridinone} and grown under high light intensity (10.8 klux), was markedly reduced. Corn and wheat germinated from seeds treated with 10 uM fluridone and grown for 6 days were almost completely bleached. Under low light intensity (108 lux) the influence of fluridone on chlorophyll production was greatly reduced. Under very low light intensity (21.5 lux) this influence was almost completely lost. The effect of light on the activity of fluridone suggests that the inhibition of carotenoid production may represent the mode of action of this herbicide. This study shows that the carotenoid content of wheat or corn drops dramatically when these plants are treated with fluridone.

Fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4 (1H)-pyridinone} and R-4-0244 [1-(m-trifluoromethylphenyl)-3-chloro-4-chloromethyl-2-pyrrolidone], herbicides that block carotenoid synthesis, increase the sensitivity of corn (Zea mays L. ‘Merit’) to exogenously-applied gibberellic acid (GA). Increase in shoot length due to the application of GA to imbibing corn seeds was considerably enhanced by simultaneously applying either fluridone or R-40244. Fluridone was more active in this respect than R-40244.

Hydrilla is one of the most serious aquatic weed problems in the United States, and fluridone is the United States Environment Protection Agency (USEPA)-approved herbicide that provides relatively long-term systemic control. Mature (6-wk-old) and young (freshly planted from 10-cm apical shoot apices) hydrilla were grown in 540 L fiberglass vaults under short- (natural 8 to 10 hr light/14 to 16 hr dark photoperiod) or long- (artificially extended 16 h light/8 h dark photoperiod) day greenhouse conditions. Fluridone treatments of 0, 1, 5, and 10 µg L−1 were applied after 2 wk and maintained within each population and photoperiodic regime throughout the study. Short days promoted subterranean turion formation, but this effect was reduced by long days and 5 and 10 µg L−1 fluridone. Fluridone caused a reduction in chlorophyll and carotenoid levels but the effect on anthocyanin content was variable. Short days caused elevated anthocyanin, and this effect was diminished by fluridone. Fluridone reduced the abscisic acid content of mature apical stems and was higher under short days in younger plants. These studies provide further evidence that fluridone can be used as a fall herbicide application to reduce turion production.

Mesotrione, topramezone, and tembotrione inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD), an enzyme integral to carotenoid biosynthesis. Research was conducted to evaluate the response of hybrid bermudagrass following mesotrione (280, 350, and 420 g ai ha−1), topramezone (18, 25, and 38 g ai ha−1), and tembotrione (92, 184, and 276 g ai ha−1) applications. Measurements of visual bleaching (VB) and chlorophyll fluorescence yield (Fv/Fm) were evaluated 3, 5, 7, 14, 21, 28, and 35 d after application (DAA). Leaf tissues were sampled on the same dates and assayed for chlorophyll and carotenoid pigments using high-performance liquid chromatography (HPLC). Responses of plants treated with topramezone and tembotrione were similar; these herbicides caused more VB and greater reductions in Fv/Fm, total chlorophyll, lutein, and xanthophyll cycle pigment concentrations than mesotrione 5 to 21 DAA. Increasing mesotrione application rate did not increase VB or lead to greater reductions in total chlorophyll, lutein, or xanthophyll pigment concentrations. Alternatively, increasing topramezone and tembotrione application rates above 18 and 92 g ha−1, respectively, extended VB and pigment reductions. Of the three HPPD-inhibitors tested, topramezone was the most active, because the low (18 g ha−1) rate of topramezone reduced lutein and total xanthophyll pigment concentrations more than the low rate of tembotrione (92 g ha−1) during periods of maximum activity (14 to 21 DAA). No necrosis was observed with any of the treatments, suggesting tank mixtures of topramezone with other herbicides might be required to provide long-term control of hybrid bermudagrass.

The present study investigates the potential of algal oil (extracted from Nannochloropsis salina), cod liver oil, olive oil and yeast for live prey enrichments in A. percula larviculture. After hatching, larvae were divided into six experimental groups as follows. Larvae fed on non-enriched (control), cod liver oil enriched, olive oil enriched, algal oil enriched, yeast enriched live prey and wild collected mixed plankton. Growth (total length, standard length, body depth, head depth and weight), survival, carotenoid and PUFAs content were observed at higher levels in juveniles fed on wild plankton and algal oil enriched diets. Thyroid hormones (T3, T4 and TSH) levels were also higher in the juveniles fed on wild plankton followed by algal oil enriched diet. Based on the present study, it can be concluded that mixed zooplankton and algal oil enriched rotifers Brachionus plicatilis and Artemia nauplii may be considered suitable live prey for clownfish larviculture.

The reaction of free radicals with polyunsaturated fatty acids (PUFAs) initiates a chain-reaction process known as lipid peroxidation in living systems and oxidative rancidity in foods. PUFAs are more susceptible to oxidation, resulting in the formation of toxic products. As embryonic tissues are characterised by high concentration of PUFAs, the use of antioxidants in broiler breeder diets improves chick oxidative status. Eggs ‘in shell’ are considered resistant to oxidative rancidity, however studies showed that yolk lipids within table eggs oxidise during storage and this oxidation is influenced by time and temperature of storage and the degree of unsaturation of yolk fatty acids. Thus, experiments into supplementing laying hen diet with antioxidants have been conducted to preserve the table eggs nutritional value. The literature shows that vitamin E has antioxidant activity in the egg yolk, protecting embryonic tissues efficiently during incubation and in the first days of a chick's life. However, these studies have not considered the effect of this vitamin on incubation yield. Without this economic variable, the positive results observed in the embryo and for chick oxidative status have little value for application in the field, mainly because the concentrations recommended in studies are much higher than those used in practice. Other antioxidants, e.g. canthaxanthin, act in synergy with vitamin E, however, the high cost of these ingredients could prevent its use for broiler breeders. This review discusses the effect of vitamins (especially vitamin E) in broiler breeder's and laying hens nutrition on oxidative stability of embryonic tissues and table egg yolk lipids, respectively.

Dietary bioactive compounds (vitamin E, carotenoids, polyphenols, vitamin C, Se and Zn) have beneficial effects on skin health. The classical route of administration of active compounds is by topical application direct to the skin, and manufacturers have substantial experience of formulating ingredients in this field. However, the use of functional foods and oral supplements for improving skin condition is increasing. For oral consumption, some dietary components could have an indirect effect on the skin via, for example, secondary messengers. However, in the case of the dietary bioactive compounds considered here, we assume that they must pass down the gastrointestinal tract, cross the intestinal barrier, reach the blood circulation, and then be distributed to the different tissues of the body including the skin. The advantages of this route of administration are that the dietary bioactive compounds are metabolized and then presented to the entire tissue, potentially in an active form. Also, the blood continuously replenishes the skin with these bioactive compounds, which can then be distributed to all skin compartments (i.e. epidermis, dermis, subcutaneous fat and also to sebum). Where known, the distribution and mechanisms of transport of dietary bioactive compounds in skin are presented. Even for compounds that have been studied well in other organs, information on skin is relatively sparse. Gaps in knowledge are identified and suggestions made for future research.

Avian eggs differ so much in their colour and patterning from species to species that any attempt to account for this diversity might initially seem doomed to failure. Here I present a critical review of the literature which, when combined with the results of some comparative analyses, suggests that just a few selective agents can explain much of the variation in egg appearance. Ancestrally, bird eggs were probably white and immaculate. Ancient diversification in nest location, and hence in the clutch's vulnerability to attack by predators, can explain basic differences between bird families in egg appearance. The ancestral white egg has been retained by species whose nests are safe from attack by predators, while those that have moved to a more vulnerable nest site are now more likely to lay brown eggs, covered in speckles, just as Wallace hypothesized more than a century ago. Even blue eggs might be cryptic in a subset of nests built in vegetation. It is possible that some species have subsequently turned these ancient adaptations to new functions, for example to signal female quality, to protect eggs from damaging solar radiation, or to add structural strength to shells when calcium is in short supply. The threat of predation, together with the use of varying nest sites, appears to have increased the diversity of egg colouring seen among species within families, and among clutches within species. Brood parasites and their hosts have probably secondarily influenced the diversity of egg appearance. Each drives the evolution of the other's egg colour and patterning, as hosts attempt to avoid exploitation by rejecting odd-looking eggs from their nests, and parasites attempt to outwit their hosts by laying eggs that will escape detection. This co-evolutionary arms race has increased variation in egg appearance both within and between species, in parasites and in hosts, sometimes resulting in the evolution of egg colour polymorphisms. It has also reduced variation in egg appearance within host clutches, although the benefit thus gained by hosts is not clear.

Colour patches are complex traits, the components of which may evolve independently through a variety of mechanisms. Although usually treated as simple, two-dimensional characters and classified as either structural or pigmentary, in reality colour patches are complicated, three-dimensional structures that often contain multiple pigment types and structural features. The basic dermal chromatophore unit of fishes, reptiles and amphibians consists of three contiguous cell layers. Xanthophores and erythrophores in the outermost layer contain carotenoid and pteridine pigments that absorb short-wave light; iridophores in the middle layer contain crystalline platelets that reflect light back through the xanthophores; and melanophores in the basal layer contain melanins that absorb light across the spectrum. Changes in any one component of a chromatophore unit can drastically alter the reflectance spectrum produced, and for any given adaptive outcome (e.g. an increase in visibility), there may be multiple biochemical or cellular routes that evolution could take, allowing for divergent responses by different populations or species to similar selection regimes. All of the mechanisms of signal evolution that previously have been applied to single ornaments (including whole colour patches) could potentially be applied to the individual components of colour patches. To reach a complete understanding of colour patch evolution, however, it may be necessary to take an explicitly multi-trait approach. Here, we review multiple trait evolution theory and the basic mechanisms of colour production in fishes, reptiles and amphibians, and use a combination of computer simulations and empirical examples to show how multiple trait evolution theory can be applied to the components of single colour patches. This integrative perspective on animal colouration opens up a host of new questions and hypotheses. We offer specific, testable functional hypotheses for the most common pigmentary (carotenoid, pteridine and melanin) and structural components of vertebrate colour patches.

Carotenoid contents of terrestrial cyanobacteria sampled from rock surfaces with different exposure to sunlight were studied in the Guyana-shield region of Venezuela. At the collecting locations of two table mountains Roraima-tepui (2700 m), Auyan-tepui (2000 m) and an inselberg near Puerto Ayacucho (80 m), the most frequent species were Stigonema ocellatum, Stigonema hormoides and Scytonema crassum, respectively. Usually, these species were associated with the unicellular cyanobacterium Gloeocapsa sanguinea. Their carotenoid and chlorophyll a contents were determined by high-performance liquid chromatography. In general, carotenoids consisted almost equally of myxolglycosides and of β-carotene derivatives, such as β-carotene, echinenone and canthaxanthin. On a chlorophyll a basis, myxolglycoside content increased in full exposure to solar irradiation. The relative proportions of the different β-carotene derivatives appeared to be even more strongly influenced by irradiance. Whereas their total amount was increased at full exposure, the content of β-carotene decreased and that of canthaxanthin increased. Maximal ratios of canthaxanthin/β-carotene of around 5 were observed in the most sun-exposed samples. We conclude that acclimation of the carotenoid content to irradiance, especially the adjustment of the ratio canthaxanthin/β-carotene, is a response found in many different terrestrial cyanobacterial species. However, when a natural population was artificially shaded for 6 days, short-term acclimation in pigment content was not detected. The results support a photoprotective function of canthaxanthin in terrestrial cyanobacteria under natural environmental conditions.

The dynamics of astaxanthin and canthaxanthin were studied through an 11-month feeding experiment by following carotenoid deposition in male and female rainbow trout muscle, during and after spawning. Carotenoids were analysed by chromatography (HPLC), muscle colour was measured by a colourimeter and visual rank evaluation. In both sexes, a decrease in the muscle carotenoid content was observed at spawning time. The recovery of the muscle pigmentation differed between females and males, but seemed not to be influenced by the type of carotenoid additives in feed. The carotenoid content of the female muscle increased rapidly after spawing, while in the male this increase was slower. Eighteen weeks after spawing, carotenoid concentrations in the muscle of females corresponded to those before spawning, while in males they reached only one third of that amount. Significant correlations were found between chemical analysis, colourimetric measurements and visual rank evaluation.