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PubMed2005

Quantitative trait loci governing carotenoid concentration and weight in seeds of chickpea (Cicer arietinum L.).

Chickpea is a staple protein source in many Asian and Middle Eastern countries. The seeds contain carotenoids such as beta-carotene, cryptoxanthin, lutein and zeaxanthin in amounts above the engineered beta-carotene-containing "golden rice" level. Thus, breeding for high carotenoid concentration in seeds is of nutritional, socio-economic, and economic importance. To study the genetics governing seed carotenoids in chickpea, we studied the relationship between seed weight and concentrations of beta-carotene and lutein by means of high-performance liquid chromatography in segregating progeny from a cross between an Israeli cultivar and wild Cicer reticulatum Ladiz. Seeds of the cross progeny varied with respect to their carotenoid concentration (heritability estimates ranged from 0.5 to 0.9), and a negative genetic correlation was found between mean seed weight and carotenoid concentration in the F(3). To determine the loci responsible for the genetic variation observed, the population was genotyped using 91 sequence tagged microsatellite site markers and two CytP450 markers to generate a genetic map consisting of nine linkage groups and a total length of 344.6 cM. Using quantitative data collected for beta-carotene and lutein concentration and seed weight of the seeds of the F(2) population, we were able to identify quantitative trait loci (QTLs) by interval mapping. At a LOD score of 2, four QTLs for beta-carotene concentration, a single QTL for lutein concentration and three QTLs for seed weight were detected. The results of this investigation may assist in improving the nutritional quality of chickpea.

Carotenoids↗
PubMedDate not supplied

Carotenoids of an Antarctic psychrotolerant bacterium, Sphingobacterium antarcticus, and a mesophilic bacterium, Sphingobacterium multivorum.

The major carotenoid pigments of an Antarctic psychrotolerant bacterium, Sphingobacterium antarcticus, and a mesophilic bacterium, Sphingobacterium multivorum, were identified as zeaxanthin, beta-cryptoxanthin, and beta-carotene. Analysis was based on ultraviolet-visible spectroscopy, mass spectroscopy, and reversed-phase HPLC. Photoacoustic spectroscopy of intact bacterial cells revealed that the bulk of the pigments in S. antarcticus and S. multivorum was associated with the cell membrane. In vitro studies with synthetic membranes of phosphatidylcholine demonstrated that the major pigment was bound to the membranes and decreased their fluidity. The relative amounts of polar pigments were higher in cells grown at 5 degrees C than in cells grown at 25 degrees C. In the mesophilic strain, the synthesis of polar carotenoids was quantitatively less than that of the psychrotolerant strain.

Antarctic Regions↗
PubMed1996

Certification of fat-soluble vitamins, carotenoids, and cholesterol in human serum: Standard Reference Material 968b.

In Standard Reference Material 968b, fat-soluble vitamins and cholesterol in human serum, certified values are provided for cholesterol, retinol, retinyl palmitate, alpha-tocopherol, trans-beta-carotene, total beta-carotene ( trans plus cis isomers), total alpha-carotene, and lutein. Non-certified values are also reported for gamma-tocopherol (includes beta-tocopherol), delta-tocopherol, zeaxanthin, beta-cryptoxanthin, trans-lycopene, trans-lycopene, trans-alpha-carotene, total lycopene, 9- cis-betacarotene, 13- plus 15- cis-beta-carotene, and 15- cis-beta-carotene. Both certified and non-certified values are based on the agreement among results from three different liquid chromatographic analytical procedures developed at NIST and from an interlaboratory comparison exercise among institutions that participate in a NIST-managed Micronutrients Measurement Quality Assurance Program. Cholesterol is certified in this material using the NIST isotope dilution/mass spectrometric definitive method.

Journal Article↗
PubMed2005

Microbial xanthophylls.

Xanthophylls are oxygenated carotenoids abundant in the human food supply. Lutein, zeaxanthin, and cryptoxanthin are major xanthophyll carotenoids in human plasma. The consumption of these xanthophylls is directly associated with reduction in the risk of cancers, cardiovascular disease, age-related macular degeneration, and cataract formation. Canthaxanthin and astaxanthin also have considerable importance in aquaculture for salmonid and crustacean pigmentation, and are of commercial interest for the pharmaceutical and food industries. Chemical synthesis is a major source for the heavy demand of xanthophylls in the consumer market; however, microbial producers also have potential as commercial sources. In this review, we discuss the biosynthesis, commercial utility, and major microbial sources of xanthophylls. We also present a critical review of current research and technologies involved in promoting microbes as potential commercial sources for mass production.

Bacteria↗
PubMed2002

Plasma concentration response to drinks containing beta-carotene as carrot juice or formulated as a water dispersible powder.

BACKGROUND: Bioavailability of beta-carotene is highly variable and depends on the source, the formulation and other nutritional factors. OBJECTIVE: It was the aim of the study to compare beta-carotene plasma response to b-carotene dosing with two commercially available drinks, containing beta-carotene from carrot juice or as water dispersible beta-carotene powder. Design In a randomized, parallel group study design, 4 volunteers per group received daily beta-carotene doses of 6-7 or 18-22 mg of either drink over 6 weeks. Blood samples for determination of carotenoid and vitamin A plasma concentrations were collected before supplementation and over the dosing period. RESULTS: Apparent steady-state beta-carotene concentrations were attained after 40 days of supplementation. Consumption of the beverage containing beta-carotene as a water dispersible powder resulted in a higher response of beta-carotene plasma concentrations with increments of 3.84 +/- 0.60 micromol/L (p < 0.05, dose: 7.2 mg/d) and 5.04 +/- 0.72 micromol/L (p < 0.05, dose: 21.6 mg/d), respectively, in comparison to the carrot juice-based drink with increments of 0.42 +/- 0.33 micromol/L (dose: 6 mg/d) and 1.71 +/- 0.55 micromol/L (dose: 18 mg/d), respectively. beta-carotene was cleared from the plasma with an apparent half-life of 6-11 days. Plasma concentrations of alpha-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene remained almost unchanged, whereas retinol plasma concentrations increased slightly. By contrast, with the exception of elevated 13-cis-retinoic acid in one group (21.6 mg/d, water dispersible powder), the concentrations of all-trans-retinoic acid, and the oxo-derivatives or retinoic acid were not significantly affected by b-carotene supplementation. CONCLUSIONS: The results confirm that the relative bioavailability of beta-carotene depends largely on the source of b-carotene and demonstrate the superior bioavailability of beta-carotene powder in comparison to that in carrot juice.

Adult↗
PubMed2004

Effect of the stage of lactation in humans on carotenoid levels in milk, blood plasma and plasma lipoprotein fractions.

In mammals the composition of milk changes during early lactation, with a rapid decline of fat-soluble vitamins and a continuous increase in total lipids. The mechanisms underlying this phenomenon are not well understood, but might involve selective mechanisms related to mammary uptake or secretion into the milk. Since carotenoids are specifically distributed among the lipoprotein fractions in plasma, the simultaneous determination of carotenoids in plasma, lipoprotein fractions and milk might offer an opportunity to gain insight into this phenomenon. In 21 healthy mothers carotenoids in plasma and lipoprotein fractions were investigated at day 2 and 19 and milk on day 4 and 19 after delivery. Plasma levels of alpha-tocopherol and cholesterol as well as lutein, zeaxanthin and cryptoxanthin were significantly lower later in lactation (day 19) than shortly after birth (P < 0.01). The stage of lactation had no effect on the distribution of carotenoids and alpha-tocopherol among the plasma lipoprotein fractions. In milk, triacylglycerol increased (P < 0.01). In contrast, levels of carotenoids, alpha-tocopherol and vitamin A were highest in colostrum and declined (P < 0.01). Because the magnitude of decrease was not the same in all carotenoids, the carotenoid pattern changed substantially. In colostrum the carotenoid pattern resembled those of plasma and the low-density lipoprotein fraction. In mature milk it was similar to the pattern found in the high density lipoprotein fraction. Based on these observations a selective mechanism might be responsible for the transfer of these components in milk involving different lipoprotein fractions at specific times of lactation.

Adult↗
PubMed1999

Intestinal absorption of lycopene from different matrices and interactions to other carotenoids, the lipid status, and the antioxidant capacity of human plasma.

BACKGROUND: The bioavailability of carotenoids has been investigated in animal studies as well as in human studies, so far mostly for beta-carotene. Only few results exist for lycopene. In recent studies, lycopene was significantly better available from processed tomatoes compared to raw tomatoes, when using daily intakes between 16.5 mg and 75 mg lycopene. AIM OF THE STUDY: In a comparative study the availability of a low oral lycopene dosage of 5 mg/d from different food matrices versus soft gel capsules containing tomato oleoresin was assessed. In addition to the plasma carotenoid content, the effect of lycopene ingestion on other plasma carotenoids, the lipid status parameters, and the antioxidant activity was estimated. METHODS: Twenty-two female adults (20-27 y) were randomized in three groups and were advised to minimize their carotenoid intake for two weeks. After this initial period, two groups received a portion of tomatoes or tomato juice adjusted to a lycopene dose of 5 mg/d, the third group ingested the same dose comprised in soft gel capsules containing tomato oleoresin. During the test period of 6 weeks, the participants continued reducing the intake of carotenoids from food. Fasting blood samples were withdrawn prior to the study, before supplementation started, and then weekly while supplemented. Seven-day dietary records were prepared before the study started and after one week of supplementation. Carotenoids were analyzed by reversed phase HPLC with diode array detection. Dietary records were evaluated using the computer software EBIS 2.1. The plasma total cholesterol, HDL cholesterol, and triglycerides were determined enzymatically. In addition, the antioxidant activity of plasma was estimated by using the TEAC and the TRAP assays. RESULTS: The basal levels of lycopene in plasma were comparable for all groups (0.2-0.3 mumol/l) and decreased significantly during the two weeks of depletion to approximately 50% of the basal values. Other plasma carotenoids such as beta-carotene and beta-cryptoxanthin decreased significantly, too, whereas lutein and zeaxanthin remained unchanged. After supplementation with tomato oleoresin capsules or tomato juice, the plasma lycopene increased significantly, while it remained unchanged during intake of tomatoes. Normal dietary habits were practised of all volunteers before and during the study except vitamin C whose intake was significantly lower during the study period, because the probands were recommended to reduce the intake of fruits and vegetables. Lycopene supplementation did not affect the lipid status parameters of the three groups. After ingestion of lycopene the antioxidant activity of the plasma was not altered. Mean TEAC values were estimated to 0.33 +/- 0.05 mmol/l and TRAP values to 1.0 +/- 0.1 mmol/l and showed no significant differences in all groups during the whole study period. CONCLUSIONS: The bioavailability of lycopene varied significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. The daily intake of 5 mg lycopene, an intake comparable to the usual daily carotenoid intake, did not affect cholesterol and triglycerides in plasma or its antioxidant capacity.

Adult↗
PubMed2001

Relationship between dietary intake, antioxidant status and smoking habits in female Austrian smokers.

BACKGROUND: Previous studies have shown that cigarette smoke contains many oxidants and free radicals, which can increase lipid peroxidation. AIM OF THE STUDY: The association between smoking, food pattern, especially vitamin intake and plasma concentrations of important antioxidants, as well as lipid peroxidation products was assessed in this cross-sectional study. SUBJECTS AND METHODS: Sixty Austrian women aged 18-40 y were enrolled in the study. Twenty-nine women were allocated to the smoking group; thirty-one women served as nonsmoking controls. Plasma concentrations of alpha- and gamma-tocopherol, alpha- and beta-carotene, lycopene, cryptoxanthin, retinol, ascorbate and malondialdehyde were determined by HPLC; dietary intake and food pattern had been assessed by four 24-h dietary intake recalls and one food frequency questionnaire. RESULTS: Generally, food intake patterns were not different between smoking and nonsmoking women. But, a significantly higher intake of alcohol was observed in the smoking group (P < 0.05). Plasma ascorbic acid concentration of the smoking group did not differ from the nonsmoking women. Despite the increased utilization because of the oxidative stress in smokers, this result might be explained by the high dietary intake of vitamin C in our smoking group. Significantly lower plasma concentrations of alpha-,beta-carotene and lycopene have been partly ascribed to the enhanced metabolic turnover resulting from smoking-induced oxidative stress. Our results confirm that smoking had no effects on plasma tocopherol and plasma retinol concentrations. CONCLUSIONS: The poor supply with the carotenoids alpha-, beta-carotene and lycopene may result from the increased metabolism of antioxidants caused by oxidative stress and may be responsible for significantly higher levels of lipid peroxidation products in smokers compared to nonsmokers (P < 0.05).

Adolescent↗
PubMed2006

Characterization of a beta-carotene hydroxylase of Adonis aestivalis and its expression in Arabidopsis thaliana.

Carotenoids are plant secondary metabolites that comprise two main groups: carotenes and xanthophylls. The latter group includes zeaxanthin which is synthesized by beta-carotene hydroxylase catalyzing the hydroxylation of the beta-rings of beta-carotene molecules. To develop tools to alter carotenoid biosynthesis in plants, we isolated a cDNA clone encoding a candidate beta-carotene hydroxylase, CrtH1, from the flower petals of Adonis aestivalis. CrtH1 protein has homology to beta-carotene hydroxylases from other organisms, and possesses the four histidine motifs conserved in this family of enzymes. Sequence analysis predicted the presence of a putative plastid transit peptide at the amino terminus and four transmembrane helical regions. Southern-blot analysis showed CrtH1 to be encoded by a multicopy gene family with at least three members in A. aestivalis. Analysis of CrtH1 transcript abundance by Northern blotting indicates it is highly expressed in flower petals, roots and stems, with relatively low expression in leaves and developing seeds. CrtH1 was able to catalyze the formation of zeaxanthin and its intermediate precursor beta-cryptoxanthin from beta-carotene in functional assays conducted in E. coli. Expression of CrtH1 in Arabidopsis thaliana wild type and a mutant deficient for endogenous beta-carotene hydroxylases enhanced the biosynthesis of violaxanthin in the seeds.

Adonis↗
PubMed2004

Beta-carotene production by Flavobacterium multivorum in the presence of inorganic salts and urea.

Flavobacterium multivorum, a non-fermenting Gram-negative bacteria, normally produces zeaxanthin (3R, 3' R-beta, beta-carotene-3, 3' diol) as its main carotenoid. The effect of supplementation of various inorganic salts and urea on the growth, total carotenoid production, and proportion of beta-carotene (beta, beta-carotene), beta-cryptoxanthin (beta, beta-caroten-3-ol), and zeaxanthin produced by F. multivorum was investigated. Urea and several salts, such as calcium chloride, ammonium chloride, lithium chloride, and sodium carbonate, improved total carotenoid production by 1.5- to 2.0-fold. Urea and sodium carbonate had an unexpectedly strong positive effect on beta-carotene production at the expense of zeaxanthin formation. The effect was found to be independent of incubation time, and beta-carotene represented 70% (w/w) of the total carotenoid content. The cumulative effect of urea and sodium carbonate was further studied using response surface methodology. An optimum medium was found to contain 4,000 and 4,070 mg l(-1) urea and sodium carbonate, respectively. The maximum beta-carotene level was 7.85 microg ml(-1) culture broth, which represented 80% (w/w) of the total carotenoid produced. Optimization resulted in 77- and 88-fold improvements in the volumetric and specific beta-carotene levels, respectively, accompanied by a simultaneous decrease in the zeaxanthin level as compared to the control medium. The carotenoid production profile in the optimized medium indicated that beta-carotene was produced maximally during the late exponential phase at 0.41 microg ml(-1) h(-1). It is possible that this organism could be an excellent commercial source of either beta-carotene or zeaxanthin, depending on initial culture conditions.

Culture Media↗
PubMed2002

Plant sterol esters lower plasma lipids and most carotenoids in mildly hypercholesterolemic adults.

The ability of plant sterol esters (PSE) in salad dressing to modify plasma lipids and carotenoids was determined in 26 men and 27 women fed controlled, weight-maintaining, isocaloric diets. Diets contained typical American foods that provided 32% of energy from fat. Dressings contained 8 g (ranch) or 4 g (Italian) of fat per serving. PSE (3.6 g/d) were provided in two servings/d of one of the dressings. Diets with ranch or Italian dressing without and with PSE were fed for 3 wk/diet and crossed over randomly within dressings. Diets were adjusted to similar fat and fatty acid concentrations. Type of salad dressing did not affect plasma lipids, lipoproteins, carotenoids, or fat-soluble vitamins (P > 0.05). Switching from a self-selected baseline diet to the control diet resulted in reduction in low density lipoprotein (LDL) cholesterol of 7.9%, a decrease in high density lipoprotein (HDL) cholesterol of 3.1%, and a decrease in triglycerides (TG) of 9.3%. Consumption of 3.6 g of PSE resulted in further decreases in LDL cholesterol (9.7%) and TG (7.3%) but no additional change in HDL cholesterol. Total plasma carotenoids decreased 9.6% with PSE. An automated stepwise procedure was developed to produce candidate mixed models relating plasma carotenoid response to PSE. These models adjusted for preintervention plasma carotenoid levels and effects of diets on blood lipids. There were significant decreases in beta-carotene, alpha-carotene, and beta-cryptoxanthin (females only) not associated with changes in plasma lipids. Plasma carotenoids on all diets remained within normal ranges. We conclude that low-fat foods, such as salad dressings, are effective carriers for PSE.

Adult↗
PubMed1991

Carotenoid composition in the cyanobacterium Phormidium laminosum. Effect of nitrogen starvation.

When pigments of the non-N2-fixing cyanobacterium Phormidium laminosum were carefully extracted and analyzed in a completely O2-free atmosphere, by either high performance liquid chromatography (HPLC) or thin layer chromatography (TLC), the presence of only two carotenoids (namely, beta-carotene and nostoxanthin) was detected. However, exposure of pigments to an air atmosphere during their manipulation led to the rapid appearance in the organic extracts of at least three additional carotenoids (identified as caloxanthin, zeaxanthin and beta-cryptoxanthin). This fact could explain the presence in cyanobacteria of such hydroxylated derivatives of beta-carotene widely reported in the literature. Nitrogen starvation also resulted in an important decrease on the relative beta-carotene/nostoxanthin content of cells, suggesting that this nutritional condition affects thylakoid membranes more drastically than cytoplasmic membranes.

Carotenoids↗
PubMed1995

The influence of smoking and diet on the hypoxanthine phosphoribosyltransferase (hprt) mutant frequency in circulating T lymphocytes from a normal human population.

The influence of the dietary antioxidants vitamin C, alpha- and beta-carotene, lycopene, lutein/zeaxanthin, phytofluene, beta-cryptoxanthin, retinol and alpha- and gamma-tocopherol on the hypoxanthine phosphoribosyltransferase (hprt) mutant frequency in human peripheral T lymphocytes was investigated. Twenty-five male non-smokers and 27 male smokers in the age range 50-59 years were recruited. Smokers showed a significantly higher mutant frequency compared with non-smokers (X1.5, P < 0.01). In addition, there was a significant positive relationship between hprt mutant frequency and the number of cigarettes that individuals reported smoking daily (P < 0.01). Smokers showed significantly lower levels of plasma vitamin C and the carotenoid alpha-carotene than non-smokers (P < 0.01 and P < 0.05 respectively). Both hprt mutant frequency and lymphocyte plating efficiency were weakly inversely associated with plasma vitamin C levels (P < 0.07 and P < 0.06 respectively) suggesting that vitamin C may be protective against mutation at the hprt locus. This relationship was markedly stronger in smokers (P < 0.01).

Adult↗
PubMed1995

Carotenoids and tocopherols in various hepatobiliary conditions.

BACKGROUND: Previous studies revealed hepatic interactions of beta-carotene with alcohol in non-human primates, but bile carotenoids and alpha-tocopherol have not previously been explored in man. METHODS: To compare the plasma and biliary concentrations of carotenoids, retinoids and tocopherols among controls and patients with biliary and pancreatic diseases, these compounds were measured by high performance liquid chromatography in bile collected during 41 endoscopic retrograde cholangiopancreatographies. RESULTS: In 14 subjects with normal endoscopic retrograde cholangiopancreatography (controls), bile contained beta-carotene, alpha-carotene, lycopene, cryptoxanthin, lutein+zeaxanthin (23.9 +/- 6.6, 3.9 +/- 1.1, 39.9 +/- 21.6, 22.5 +/- 4.6, 217.1 +/- 27.8 nmol/l, respectively) with corresponding plasma values of 399.7 +/- 72.6, 88.5 +/- 18.8, 588.2 +/- 75.0, 145.1 +/- 25.9, 319.3 +/- 33.7 nmol/l. In 13 patients in whom bile duct stones impaired biliary excretion (as reflected by raised serum bilirubin), beta-carotene was significantly decreased in both plasma (199.6 +/- 35.5 nmol/l) and bile (9.4 +/- 2.0 nmol/l), with a similar trend for other carotenoids. The beta-carotene plasma/bile ratio was maintained, as well as a correlation between the two (r = 0.56; p = 0.048). Furthermore, in three subjects with complete biliary obstruction, plasma beta-carotene (35.8 +/- 20.2 nmol/l) decreased even more, probably reflecting malabsorption. In 11 patients with pancreatic diseases, plasma and bile beta-carotene were 107.9 +/- 17.8 and 6.6 +/- 2.0 nmol/l respectively, while a correlation between the two (r = 0.70; p = 0.018) again persisted, confirming the role of plasma beta-carotene in determining bile concentrations. Indeed, for the entire group (n = 41), the correlation between plasma and bile or red blood cell beta-carotene was highly significant, whereas plasma/red blood cell ratios remained unchanged. Similar findings were observed for alpha-tocopherol, with 8.4 +/- 0.9 mumol/l in control bile (vs. 23.2 +/- 1.7 mumol/l in plasma), and no significant change in the various groups. CONCLUSIONS: 1) Carotenoids and tocopherols undergo biliary excretion in man. 2) Biliary concentrations reflect plasma levels in both normal and pathologic states. 3) Decreased biliary excretion of carotenoids does not increase plasma concentrations.

Adult↗
PubMed1987

Occurrence of carotenoids and sporopollenin in Nanochlorum eucaryotum, a novel marine alga with unusual characteristics.

Pigment analysis of Nanochlorum eucaryotum on two strains grown under different gaseous conditions was performed. Air-gassed control cultures did not differ qualitatively with respect to the content of chlorophylls a and b, carotenes alpha and beta, lutein, violaxanthin, neoxanthin and cryptoxanthin in comparison with cultures grown under natural gas. The absolute pigment content per cell increased in cultures grown with natural gas. Growth of N. eucaryotum depends on CO2 which is present in concentrations up to 2.0 vol% in natural gas. N. eucaryotum cannot utilize methane and is therefore not methylotrophic. In cultures of N. eucaryotum grown with natural gas and in air-gassed cultures under nitrogen deficient conditions the secondary carotenoids canthaxanthin and astaxanthin could be detected. In air-gassed cultures of strain N. eucaryotum Colona the same secondary carotenoids have been found, while secondary carotenoids were never found in strain N. eucaryotum Mainz. Cell walls of N. eucaryotum always contain sporopollenin as confirmed by isolation, elemental analysis, infrared absorption spectrophotometry, acetolysis-resistance and electron microscopy.

Biopolymers↗
PubMed1990

Identification of carotenoids in Erwinia herbicola and in a transformed Escherichia coli strain.

The yellow pigments of Erwinia herbicola Eho 10 and of a transformed Escherichia coli LE392 pPL376 have been identified as carotenoids. HPLC separation, spectra and in some cases mass spectroscopy demonstrated the presence of phytoene (15-cis isomer), beta-carotene (all-trans, 9-cis and 15-cis), beta-cryptoxanthin ( = 3-hydroxy beta-carotene), zeaxanthin (3,3'-dihydroxy beta-carotene) and corresponding carotene glycosides. In addition, lycopene and gamma-carotene accumulated in the presence of the inhibitor 2-(4-chlorophenylthio)-triethylamine.HCl. Carotenoid content in the transformed E. coli was two-fold higher than in E. herbicola. The pattern of the carotenoids was similar in the two organisms. Inactivation of the katF gene in E. coli resulted in an 85% lowering of carotenoid formation, as did the addition of 0.5% glucose to the medium. Suppression of carotenoid formation by inactivation of the katF gene lowered, but did not abolish, the protection offered by carotenoids against inactivation by alpha-terthienyl plus near-ultraviolet light (320-400 nm).

Carotenoids↗
PubMed1988

Carotenoids, retinoids and alpha-tocopherol in human serum: Identification and determination by reversed-phase HPLC.

A rapid, simple and specific high performance liquid chromatographic procedure for assaying alpha- and beta-carotene is described. The method also enables the simultaneous determination of retinol and dl-alpha-tocopherol in human serum. The same chromatographic procedure can be used to assay the major carotenoids in human serum, provided analyses are replicated and the effluent is monitored at 450 nm. The conditions described also enable determination of licopene, cryptoxanthine and lutein with zeaxanthine. An aliquot of 0.5 ml serum is deproteinized with ethanol (0.5 ml) and extracted with petroleum ether (0.75 ml). The petroleum ether extract is evaporated until dry and then redissolved immediately with 0.5 ml of an eluent mixture consisting of methanol-hexane (85:15, v/v). Aliquots of 50 microl are then injected onto a 250 x 4.6 mm column packed with Spherisorb ODS-2. Owing to its good reproducibility, the procedure can be used for assays with external standards. Clinical applications are described for cases of hypercarotinemia associated with endocrine dysfunctions such as hypothyroidism and diabetes.

Journal Article↗
PubMed2004

Carotenoid pigments and the selectivity of psittacofulvin-based coloration systems in parrots.

Carotenoid pigments are commonly used as colorants of feathers and bare parts by birds. However, parrots (Aves: Psittaciformes) use a novel class of plumage pigments (called psittacofulvins) that, like carotenoids, are lipid-soluble and red, orange, or yellow in color. To begin to understand how and why parrots use these pigments and not carotenoids in their feathers, we must first describe the distribution of these two types of pigments in the diet, tissues, and fluids of these birds. Here, we studied the carotenoid content of blood in five species of parrots with red in their plumage to see if they show the physiological ability to accumulate carotenoids in the body. Although Scarlet (Ara macao) and Greenwing Macaws (Ara chloroptera) and Eclectus (Eclectus roratus), African Gray (Psittacus erithacus) and Blue-fronted Amazon (Amazona aestiva) Parrots all use psittacofulvins to color their feathers red, we found that they also circulated high concentrations of both dietary (lutein, zeaxanthin, beta-cryptoxanthin) and metabolically derived (anhydrolutein, dehydrolutein) carotenoids through blood at the time of feather growth, at levels comparable to those found in many other carotenoid-colored birds. These results suggest that parrots have the potential to use carotenoids for plumage pigmentation, but preferentially avoid depositing them in feathers, which is likely under the control of the maturing feather follicle. As there is no evidence of psittacofulvins in parrot blood at the tune of feather growth, we presume that these pigments are locally synthesized by growing feathers within the follicular tissue.

Animals↗