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PubMed2005

Carotenoid transport is decreased and expression of the lipid transporters SR-BI, NPC1L1, and ABCA1 is downregulated in Caco-2 cells treated with ezetimibe.

Data suggest that intestinal carotenoid absorption is a facilitated process. The present study was conducted to determine whether carotenoids and cholesterol share common pathways (transporters) for their intestinal absorption. Differentiated Caco-2 cells on membranes were incubated (16 h) with a carotenoid (1 micromol/L) with or without ezetimibe (EZ; Zetia, an inhibitor of cholesterol transport), and with or without antibodies against the receptors, cluster determinant 36 (CD36) and scavenger receptor class B, type I (SR-BI). Carotenoid transport in Caco-2 cells (cellular uptake + secretion) was decreased by EZ (10 mg/L) as follows: beta-carotene approximately alpha-carotene (50% inhibition) >> beta-cryptoxanthin approximately lycopene (20%) >> lutein:zeaxanthin (1:1) (7%). EZ reduced cholesterol transport by 31%, but not retinol transport. beta-Carotene transport was also inhibited by anti-SR-BI, but not by anti-CD36. The inhibitory effects of EZ and anti-SR-BI on beta-carotene transport were additive, indicating that they may have different targets. Finally, differentiated Caco-2 cells treated with EZ showed a significant decrease in mRNA expression for the surface receptors SR-BI, Niemann-Pick type C1 Like 1 protein (NPC1L1), and ATP-binding cassette transporter, subfamily A (ABCA1) and for the nuclear receptors retinoid acid receptor (RAR)gamma, sterol-regulatory element binding proteins (SREBP)-1 and -2, and liver X receptor (LXR)beta as assessed by real-time PCR analysis. The data indicate that 1) EZ is an inhibitor of carotenoid transport, an effect that decreases with increasing polarity of the carotenoid molecule, 2) SR-BI is involved in carotenoid transport, and 3) EZ may act, not only by interacting physically with cholesterol transporters as previously suggested, but also by downregulating expression of these proteins. The cellular uptake and efflux of carotenoids, like that of cholesterol, likely involve more than one transporter.

ATP Binding Cassette Transporter 1↗
PubMed2005

Hispanic and non-Hispanic white elders from Massachusetts have different patterns of carotenoid intake and plasma concentrations.

Carotenoids have been linked with protective roles against diseases associated with aging, including cancer, cardiovascular disease, cataracts, and age-related macular degeneration. With data from a semiquantitative, validated FFQ, we examined carotenoid intake of 340 Puerto Ricans, 98 Dominicans, and 146 non-Hispanic whites (>60 y old) in Massachusetts. Compared with non-Hispanic white men, Hispanic men reported a higher intake of lycopene and lower intakes of alpha-carotene, lutein + zeaxanthin, beta-carotene (from diet only), and total beta-carotene (diet and supplements) (P < 0.001). Hispanic women reported higher intakes of beta-cryptoxanthin and lycopene but lower intakes of lutein + zeaxanthin (P < 0.001) than non-Hispanic white women. The frequency of consumption of fruit and vegetables was higher among Hispanic women, relative to non-Hispanic white women (P < 0.05). Plasma concentrations of alpha-carotene and lycopene were higher in Hispanic than in non-Hispanic white men and women. For both ethnic groups, higher intakes of carotenoids were associated with higher plasma concentrations of the respective carotenoids, except for lycopene (Hispanics) and lutein + zeaxanthin (non-Hispanic whites). Food sources contributing most to total intakes differed among the groups. The major sources of alpha- and beta-carotene were carrots for non-Hispanic whites and winter squash for Hispanics. The major source of lycopene was cooked tomato products for Hispanics, and pasta dishes for non-Hispanic whites. Traditional foods such as beans and plantains were also important contributors of carotenoids for Hispanics. Because of the potential importance of carotenoids as protective factors against chronic diseases, more attention to food-related practices associated with carotenoid intake in differing population groups is warranted.

Aged↗
PubMed1995

Intake of carotenoids and retinol in relation to risk of prostate cancer.

BACKGROUND: Several human studies have observed a direct association between retinol (vitamin A) intake and risk of prostate cancer; other studies have found either an inverse association or no association of intake of beta-carotene (the major provitamin A) with risk of prostate cancer. Data regarding carotenoids other than beta-carotene in relation to prostate cancer risk are sparse. PURPOSE: We concluded a prospective cohort study to examine the relationship between the intake of various carotenoids, retinol, fruits, and vegetables and the risk of prostate cancer. METHODS: Using responses to a validated, semiquantitative food-frequency questionnaire mailed to participants in the Health Professionals Follow-up Study in 1986, we assessed dietary intake for a 1-year period for a cohort of 47,894 eligible subjects initially free of diagnosed cancer. Follow-up questionnaires were sent to the entire cohort in 1988, 1990, and 1992. We calculated the relative risk (RR) for each of the upper categories of intake of a specific food or nutrient by dividing the incidence rate of prostate cancer among men in each of these categories by the rate among men in the lowest intake level. All P values resulted from two-sided tests. RESULTS: Between 1986 and 1992, 812 new cases of prostate cancer, including 773 non-stage A1 cases, were documented. Intakes of the carotenoids beta-carotene, alpha-carotene, lutein, and beta-cryptoxanthin were not associated with risk of non-stage A1 prostate cancer; only lycopene intake was related to lower risk (age- and energy-adjusted RR = 0.79; 95% confidence interval [CI] = 0.64-0.99 for high versus low quintile of intake; P for trend = .04). Of 46 vegetables and fruits or related products, four were significantly associated with lower prostate cancer risk; of the four--tomato sauce (P for trend = .001), tomatoes (P for trend = .03), and pizza (P for trend = .05), but not strawberries--were primary sources of lycopene. Combined intake of tomatoes, tomato sauce, tomato juice, and pizza (which accounted for 82% of lycopene intake) was inversely associated with risk of prostate cancer (multivariate RR = 0.65; 95% CI = 0.44-0.95, for consumption frequency greater than 10 versus less than 1.5 servings per week; P for trend = .01) and advanced (stages C and D) prostate cancers (multivariate RR = 0.47; 95% CI = 0.22-1.00; P for trend = .03). No consistent association was observed for dietary retinol and risk of prostate cancer. CONCLUSIONS: These findings suggest that intake of lycopene or other compounds in tomatoes may reduce prostate cancer risk, but other measured carotenoids are unrelated to risk. IMPLICATIONS: Our findings support recommendations to increase vegetable and fruit consumption to reduce cancer incidence but suggest that tomato-based foods may be especially beneficial regarding prostate cancer risk.

Adult↗
PubMed1996

Premenopausal breast cancer risk and intake of vegetables, fruits, and related nutrients.

BACKGROUND: Given the international variations in breast cancer incidence rates and the changes in breast cancer incidence among migrant populations, it has been hypothesized that diet is a factor influencing risk of this disease. Many studies indicate that a diet high in vegetables and fruits may protect against breast cancer. PURPOSE: We conducted a case-control study of diet, including the intake of non-food supplements, and premenopausal breast cancer risk. We evaluated in detail usual intake of vegetables and fruits (each measured as the total reported grams consumed for all queried vegetables and fruit), vitamins C and E, folic acid, individual carotenoids, and dietary fiber with its components. METHODS: Case patients (n=297) were identified through pathology records from hospitals in Erie and Niagara counties in western New York. They consisted of premenopausal women 40 years of age or oder who were diagnosed with breast cancer from November 1986 through April 1991. Control subjects (n=311), frequency-matched to case patients on the basis of age and county of residence, were randomly selected from New York State Department of Motor Vehicles records. In-person interviews included detailed reports of usual diet in the period 2 years before the interview. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: There was a reduction in risk associated with high intake of several nutrients. With the lowest quartile of intake as the referent, adjusted ORs for the highest quartile of intake for specific nutrients were as follows: vitamin C (OR=0.53; 95% CI=0.33-0.86), alpha-tocopheral (OR=0.55; 95% CI=0.34-0.88), folic acid (OR=0.50; 95% CI=0.31-0.82), alpha-carotene (OR=0.67; 95% CI=0.42-1.08) and beta-carotene (OR=0.46; 95% CI=0.28-0.74), lutein + zeaxanthin (OR=0.47; 95% CI=0.28.0-77), and dietary fiber from vegetables and fruits (OR=0.48; 95% CI=0.30-0.78). No association with risk was found for beta-cryptoxanthin, lycopene, or grain fiber. Fruits were weakly associated with a reduction in risk (fourth quartile OR=0.67; 95% CI=0.42-1.09). No association was found between breast cancer risk and intake of vitamins C and E and folic acid taken as supplements. A strong inverse association between total vegetable intake and risk was observed (fourth quartile OR=0.46; 95% CI=0.28-0.74). This inverse association was found to be independent of vitamin C,alpha-tocopherol, folic acid, dietary fiber, and alpha-carotene. Adjusting for beta-carotene or lutein + zeaxanthin somewhat attenuated the inverse association with vegetable intake. CONCLUSIONS: In this population, intake of vegetables appears to decrease premenopausal breast cancer risk. This effect may be related, in part, to beta-carotene and lutein + zeaxanthin in vegetables. It appears, however, that, of the nutrients and food components examined, no single dietary factor explains the effect. Evaluated components found together in vegetables may have a synergistic effect on breast cancer risk; alternatively, other unmeasured factors in these foods may also influence risk.

Adult↗
PubMed2006

The role of carotenoid cleavage dioxygenases in the regulation of carotenoid profiles during maturation in citrus fruit.

To investigate the relationship between a carotenoid profile and gene expression for carotenoid cleavage dioxygenases, three citrus varieties that exhibit different 9-cis-violaxanthin levels in their juice sacs, Satsuma mandarin (Citrus unshiu Marc.; a variety accumulating a low level of 9-cis-violaxanthin), Valencia orange (Citrus sinensis Osbeck; variety accumulating a high level of 9-cis-violaxanthin), and Lisbon lemon (Citrus limon Burm.f.; a variety accumulating an undetectable level of 9-cis-violaxanthin) were used. Three cDNAs (CitCCD1, CitNCED2, and CitNCED3) were cloned. The recombinant CitCCD1 protein cleaved beta-cryptoxanthin, zeaxanthin, and all-trans-violaxanthin at the 9-10 and 9'-10' positions and 9-cis-violaxanthin at the 9'-10' position. The recombinant CitNCED2 and CitNCED3 proteins cleaved 9-cis-violaxanthin at the 11-12 position to form xanthoxin, a precursor of abscisic acid (ABA). The gene expression of CitCCD1 increased in the flavedos and juice sacs of the three varieties during maturation. In Satsuma mandarin, the gene expression of CitNCED2 and CitNCED3 increased noticeably, accompanying a massive accumulation of ABA in the flavedo and juice sacs. In Valencia orange, the gene expression of CitNCED3 increased with a slight elevation of the ABA level in the flavedo, whereas neither the gene expression of CitNCED2 nor the ABA level increased noticeably in the juice sacs. In Lisbon lemon, the gene expression of CitNCED2 increased remarkably, accompanying increases in the ABA level in the flavedo and juice sacs. These results suggest that, in the juice sacs, the efficient cleavage reaction for ABA synthesis reduces the 9-cis-violaxanthin level in Satsuma mandarin and Lisbon lemon, whereas the low cleavage reaction maintains the predominant 9-cis-violaxanthin accumulation in Valencia orange.

Abscisic Acid↗
PubMed1991

A case-control study of nutrient status and invasive cervical cancer. II. Serologic indicators.

A study of 387 cases and 670 controls from four Latin American countries evaluated the hypothesis that lower serum levels of eight micronutrients were associated with a higher risk of invasive cervical cancer. The serologic analyses were restricted to a sample of subjects with stage I and II disease to minimize effects of the disease on the serologic markers. Ninety-four percent of eligible subjects donated blood samples, which were analyzed for carotenoids, retinol, and tocopherols by high-pressure liquid chromatography. Cases did not differ significantly from controls in mean serum levels of retinol, cryptoxanthin, lycopene, alpha-carotene, lutein, or alpha-tocopherol. The mean level of beta-carotene was lower and the mean level of gamma-tocopherol was higher among cases as compared with controls. After adjustment for age, study site, sexual and reproductive behavior, socioeconomic status, screening practices, detection of human papillomavirus types 16/18, cholesterol, and triglycerides, a trend of decreasing risk was associated with higher levels of beta-carotene (p for trend = 0.05), with the adjusted odds ratio decreasing to 0.72 for the highest versus the lowest quartile. beta-Carotene results were similar by stage of disease, which argues against an effect of disease progression on nutrient values. Unexpectedly, increasing risks were observed as the level of gamma-tocopherol increased (odds ratio = 2.09; p for trend = 0.03); however, levels were higher among stage II cases as compared with stage I cases, suggesting a metabolic alteration resulting from the disease process. The concordance in the strength and direction of the blood and dietary results, presented in the accompanying report (Herrero R, Potischman N, Brinton LA, et al., American Journal of Epidemiology 1991;134:1335-46), supports a role for beta-carotene or foods rich in beta-carotene in the etiology of cervical cancer. This study also indicates that simultaneous analysis using serologic and dietary nutrient indicators allows better discrimination of the association.

Carcinoma, Squamous Cell↗
PubMed2005

Myxol and 4-ketomyxol 2'-fucosides, not rhamnosides, from Anabaena sp. PCC 7120 and Nostoc punctiforme PCC 73102, and proposal for the biosynthetic pathway of carotenoids.

We identified the molecular structures of carotenoids in some Anabaena and Nostoc species. The myxoxanthophyll and ketomyxoxanthophyll in Anabaena (also known as Nostoc) sp. PCC 7120, Anabaena variabilis IAM M-3, Nostoc punctiforme PCC 73102 and Nostoc sp. HK-01 were (3R,2'S)-myxol 2'-fucoside and (3S,2'S)-4-ketomyxol 2'-fucoside, respectively. The glycoside moiety of the pigments was fucose, not rhamnose. The major carotenoids were beta-carotene and echinenone, and the minor ones were beta-cryptoxanthin, zeaxanthin, canthaxanthin and 3'-hydroxyechinenone. Based on the identification of the carotenoids and the completion of the entire nucleotide sequence of the genome in Anabaena sp. PCC 7120 and N. punctiforme PCC 73102, we proposed a biosynthetic pathway for the carotenoids and the corresponding genes and enzymes. Since only zeta-carotene desaturase (CrtQ) from Anabaena sp. PCC 7120 and beta-carotene ketolase (CrtW) from N. punctiforme PCC 73102 have been functionally identified, the other genes were searched by sequence homology only from the functionally confirmed genes. Finally, we investigated the phylogenetic relationships among some Anabaena and Nostoc species, including some newly isolated species.

Anabaena↗
PubMed1996

Liarozole amplifies retinoid-induced apoptosis in human prostate cancer cells.

Beta-carotene, canthaxanthin and retinoic acid (RA) inhibited growth of human DU145 prostate cancer cells by 45, 56 and 18%, respectively. Lycopene was also found to inhibit cell growth. Other carotenoids including xanthophyll (lutein), cryptoxanthin and zeaxanthin were less effective. Liarozole (a novel imidazole-derived inhibitor of intracellular RA catabolism) had a modest effect upon cell growth, this drug significantly amplified the pro-apoptotic actions of beta-carotene and RA. RA-induced expression of thymosin beta-10, an apoptotic accelerant, was associated with increased nuclear DNA nicking as measured using TUNEL. Liarozole enhanced the proapoptotic actions of RA upon DNA fragmentation in a dose-dependent manner. These actions were accompanied by inhibition of the cell survival factor bcl-2. Liarozole may thus prove useful as a novel chemotherapeutic/chemopreventive agent by boosting retinoid-induced apoptosis in the prostate.

Antineoplastic Agents↗
PubMedDate not supplied

Carotenoids and antioxidant vitamins in patients after burn injury.

Oxidative stress may contribute to secondary tissue damage and impaired immune function in patients after burn injury. The purpose of our study was to describe plasma antioxidant micronutrient concentrations in 26 adult patients admitted with extensive burn injuries (> 20 % total burn surface area) to a level-1 trauma burn center during a 21-day period after admission. The effect of administering beta-carotene was also examined with use of a prospective randomized subjects design: patients received either placebo or 30 mg/day in an enteral feeding. Plasma concentrations of alpha- and gamma-tocopherol, carotenoids (alpha and beta-carotene, lycopene, beta-cryptoxanthin, lutein), and retinol were measured with high- performance liquid chromatography, and vitamin C was quantified with spectrophotometry, at baseline and twice per week. Vitamin C, tocopherol, and retinol concentrations were low at baseline, but levels increased significantly over the study period in both groups (p < 0.05). Plasma beta-carotene concentration increased when this carotenoid was provided in the oral feeding. Otherwise, plasma carotenoid concentrations were low at baseline and remained low throughout the study period despite normalization of associated lipids.

Adolescent↗
PubMed2000

Micronutrient antioxidants in gastric mucosa and serum in patients with gastritis and gastric ulcer: does Helicobacter pylori infection affect the mucosal levels?

Free radicals (FRs) play an important role in the pathogenesis of gastroduodenal mucosal inflammation, peptic ulcer disease, and probably even gastric cancer. Various micronutrients protect the gastric mucosa by scavenging FRs. Only limited data is available regarding the concentration of micronutrients in the gastric mucosa in patients with gastritis and peptic ulcer disease. Our aim was to analyze micronutrient antioxidant concentrations in the antral mucosa in patients with gastritis and gastric ulcer and to determine the influence of Helicobacter pylori infection on gastric mucosal antioxidants in patients with gastritis and gastric ulcer. Patients who underwent upper endoscopy for evaluation of dyspepsia were included in the study. Ascorbic acid, alpha-tocopherol, alpha-carotene, beta-carotene, total carotenoids, lutein, cryptoxanthin, and lycopene levels were measured in the sera and antral mucosal biopsies in these patients. The diagnosis of H. pylori was confirmed by histology, urease test (CLO) and serology. Patients with negative endoscopic findings and normal histology and no H. pylori infection served as controls. In patients with gastritis, alpha-tocopherol levels were reduced in serum and mucosa irrespective of H. pylori status, whereas carotenoids and ascorbic acid levels were similar to controls. However, in patients with gastric ulcer, serum and mucosal levels of all micronutrient antioxidants were markedly decreased compared with both controls and patients with gastritis. The degree of depletion of antioxidants was similar in patients with either H. pylori-induced or nonsteroidal antiinflammatory drug (NSAID)-induced ulcers. Patients with gastric ulcer have very low gastric antioxidant concentrations compared to patients with gastritis and normal mucosa. This depletion in antioxidants seems to be a nonspecific response and was not related to H. pylori infection.

Antioxidants↗
PubMed1997

Childhood vitamin A status and the risk of otitis media.

BACKGROUND: It has been suggested that vitamin A deficiency may predispose to otitis media. METHODS: We conducted a prospective, observational study of 200 children, ages 3 to 5 years, on the island of Saipan in the Commonwealth of the Northern Mariana Islands. Baseline measurements of serum retinol concentrations were obtained from the children, and incidence of otitis media was determined during the following year by review of medical records. The sera were also tested for concentration of other carotenoids (beta-carotene, alpha-carotene, lutein and zeaxanthin, beta-cryptoxanthin, lycopene), and alpha-tocopherol and baseline concentrations of these compounds were also examined for relationship to incidence of otitis media. RESULTS: Serum retinol concentrations of the children ranged from 13 to 58 microg/dl. Episodes of otitis media occurred in 22% of children during the follow-up period. Children with low serum retinol concentrations did not have an excess of episodes of otitis media (chi square for trend, 0.438; P = 0.508 for children grouped by serum retinol concentration; mean serum retinol concentrations were 29.1 and 28.6 microg/dl, respectively, for children who had and did not have a subsequent episode of otitis media). Controlling for potential confounding variables (duration of breast feeding, smoking in the household, illness or live virus vaccination in the 2 weeks before serum collection, day-care attendance) did not substantially alter this finding. Baseline serum concentrations of the other carotenoids and alpha-tocopherol also demonstrated no relation to incidence of otitis media. CONCLUSION: In the range of serum vitamin concentrations found in this population, the status of vitamin A and related compounds in children appeared to have no effect on the incidence of otitis media.

Child, Preschool↗
PubMed1996

Dietary profiles and anti-oxidants in a rural population of central Italy with a low frequency of cancer.

This descriptive, cross-sectional study reports the anti-oxidant activities of a population sample of 736 individuals, randomly selected from residents of two small towns of the Latina province of Italy (an area at low frequency of cancer). The circulating levels of vitamins A, C and E, ceruloplasmin, carotenoids (lutein + zeaxanthin, lycopene, alpha- and beta-carotene, cryptoxanthin), cholesterol, high-density lipoprotein cholesterol and triglycerides, as well as anthropometric measurements (skin-folds, height, weight) were evaluated. A dietary interview was also performed by means of a semi-quantitative questionnaire. All the anti-oxidants were above the cut-off points for normality, whereas body mass index, % fat and serum lipids were not clearly suggestive of a protected population. The data obtained could be useful to estimate the baseline values of protective microelements and to assess dietary profiles in populations following a Mediterranean diet.

Adolescent↗
PubMed1975

Comparative Study of the Carotenoid Composition of the Seeds of Ripening Momordica charantia and Tomatoes.

The total carotenoid concentration of the seeds of Momordica charantia rose about 100-fold from the immature to the ripe stage. The massive increase was almost exclusively attributable to lycopene, which accounted for 96% of the carotenoids of the ripe seeds. The carotenoid pattern of the seed was found to be drastically different from that of the pericarp. The seed, which contained fewer carotenoids, had a total concentration 12 times greater than that in the pericarp at the ripe stage. The acyclic lycopene selectively accumulated in the seed, whereas the cyclic carotenoids, cryptoxanthin, zeaxanthin and beta-carotene, were the principal pigments of the ripe pericarp. The seed of ripe tomatoes reflected the qualitative pattern of the whole fruit. The total carotenoid concentration was, however, much lower and the lycopene content was particularly low. beta-Carotene, having a comparatively high concentration, emerged as the major pigment of the seed.

Journal Article↗
PubMed1990

Growth under Red Light Enhances Photosystem II Relative to Photosystem I and Phycobilisomes in the Red Alga Porphyridium cruentum.

Acclimation of the photosynthetic apparatus to light absorbed primarily by photosystem I (PSI) or by photosystem II (PSII) was studied in the unicellular red alga Porphyridium cruentum (ATCC 50161). Cultures grown under green light of 15 microeinsteins per square meter per second (PSII light; absorbed predominantly by the phycobilisomes) exhibited a PSII/PSI ratio of 0.26 +/- 0.05. Under red light (PSI light; absorbed primarily by chlorophyll) of comparable quantum flux, cells contained nearly five times as many PSII per PSI (1.21 +/- 0.10), and three times as many PSII per cell. About 12% of the chlorophyll was attributed to PSII in green light, 22% in white light, and 39% in red light-grown cultures. Chlorophyll antenna sizes appeared to remain constant at about 75 chlorophyll per PSII and 140 per PSI. Spectral quality had little effect on cell content or composition of the phycobilisomes, thus the number of PSII per phycobilisome was substantially greater in red light-grown cultures (4.2 +/- 0.6) than in those grown under green (1.6 +/- 0.3) or white light (2.9 +/- 0.1). Total photosystems (PSI + PSII) per phycobilisome remained at about eight in each case. Carotenoid content and composition was little affected by the spectral composition of the growth light. Zeaxanthin comprised more than 50% (mole/mole), beta-carotene about 40%, and cryptoxanthin about 4% of the carotenoid pigment. Despite marked changes in the light-harvesting apparatus, red and green light-grown cultures have generation times equal to that of cultures grown under white light of only one-third the quantum flux.

Journal Article↗
PubMed2004

Inhibition of cell proliferation by nobiletin, a dietary phytochemical, associated with apoptosis and characteristic gene expression, but lack of effect on early rat hepatocarcinogenesis in vivo.

Dietary phytochemicals can inhibit the development of certain types of tumors. We here investigated the effects of nobiletin (Nob), garcinol (Gar), auraptene (Aur), beta-cryptoxanthin- and hesperidine-rich pulp (CHRP) and 1,1'-acetoxychavicol acetate (ACA) on hepatocarcinogenesis in a rat medium-term liver bioassay, and also examined their influence on cell proliferation, cell cycle kinetics, apoptosis and cell invasion of rat and human hepatocellular carcinoma (HCC) cells, MH1C1 and HepG2, respectively. While there were no obvious suppressive effects on the development of putative preneoplastic liver lesions, inhibition of hepatocarcinoma cell proliferation was evident in the Nob group. Nob also caused G2/M cell cycle arrest and apoptosis. Microarray analysis identified a set of genes specifically regulated by Nob, and these are likely to be involved in the observed growth suppression of HCC cells. These results suggest that phytochemicals might have chemopreventive potential in late stages of hepatocarcinogenesis.

Animals↗
PubMed2004

Factorial analysis of tricarboxylic acid cycle intermediates for optimization of zeaxanthin production from Flavobacterium multivorum.

AIMS: To study the effect of intermediates of the tricarboxylic acid (TCA) cycle on the production of zeaxanthin from Flavobacterium multivorum in order to optimize production of this xanthophyll carotenoid. METHODS AND RESULTS: The concentration of selected TCA cycle intermediates (malic acid, isocitric acid and alpha-ketoglutarate) was optimized in shake flask culture, using a statistical two-level, three-variable factorial approach. The carotenoid production profile was also studied in the optimized medium at various growth phases. Optimized medium resulted in a sixfold increase in volumetric production of zeaxanthin (10.65 +/- 0.63 microg ml-1) using malic acid (6.02 mm), isocitric acid (6.20 mm) and alpha-ketoglutarate (0.02 mm). The majority of zeaxanthin was produced in the late logarithmic growth phase whereas a substantial amount of beta-cryptoxanthin and beta-carotene were observed in the early logarithmic phase. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates improvement of zeaxanthin production from F. multivorum which might aid in the commercialization of zeaxanthin production from this microbe.

Bioreactors↗
PubMed1998

Plasma antioxidants and cognitive performance in middle-aged and older adults: results of the Austrian Stroke Prevention Study.

OBJECTIVES: To study the association between cognitive status and plasma concentrations of various antioxidants in middle-aged and older individuals without neuropsychiatric disease. DESIGN: Evaluation of cross-sectional data from a cohort study. SETTING: The Austrian Stroke Prevention Study. PARTICIPANTS: A total of 1769 subjects aged 50 to 75 years, with no history or signs of neuropsychiatric disease, selected randomly from the community register. MEASUREMENTS: The score on the Mattis Dementia Rating Scale (MDRS) was dichotomized according to age-and education-specific lowest quartile cut-off points. Reversed-phase high performance liquid chromatography measurements of the plasma concentrations of lutein/zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, alpha-carotene, beta-carotene, retinol, gamma-tocopherol, alpha-tocopherol, and ascorbate were measured. RESULTS: Individuals with MDRS results below the lowest quartile cut-off point had lower levels of beta-carotene and alpha-tocopherol than their counterparts with test performance above this limit (0.44+/-.33 micromol/L vs 0.51+/-.48 micromol/L, P < .001; and 29.50+/-7.98 micromol/L vs 30.93+/-11.10 micromol/L, P < .001, respectively). Only alphatocopherol remained significantly associated with cognitive functioning when logistic regression analysis was used to adjust for possible confounders including age, sex, month of blood sampling, years of education, smoking, lipid status, and major risk factors for stroke (P = .019). CONCLUSION: These observations are compatible with the view that some dietary antioxidants may protect against cognitive impairment in older people.

Age Factors↗
PubMed2001

Serum and colon mucosa micronutrient antioxidants: differences between adenomatous polyp patients and controls.

OBJECTIVES: Micronutrient antioxidants, by virtue of their free radical scavenging properties, are potential chemopreventive agents against colon cancer. Yet, little is known about the actual concentration of these antioxidants in colonic mucosa. It is also not known whether a relationship exists between serum and mucosal tissue antioxidant levels. Previous studies evaluating the occurrence of polyps after supplementation with vitamin E and beta-carotene have yielded mixed results. The aim of this study was to determine the concentrations of seven micronutrient antioxidants (alpha- and gamma-tocopherol, lutein, beta-cryptoxanthin, lycopene, and alpha- and beta-carotene) in colonic mucosa and to determine whether serum levels of each antioxidant could predict levels of that antioxidant in the right and left colon of patients with normal mucosa or in those with adenomatous polyps. METHODS: Mucosal tissue concentrations and serum levels of antioxidants were determined in 10 patients with adenomatous polyps and 15 control subjects (GI patients with normal colonic mucosa). Mucosal tissue samples were obtained from both the right and left colon in all patients. RESULTS: Patients with polyps similar serum antioxidant status similar to that of control. However, polyp patients had significantly lower concentrations of all seven antioxidants in both the right (p < 0.0070) and left colon (p < 0.0026) than did controls. Finally, serum antioxidant levels predict right and left colon antioxidant levels in controls but not in patients with polyps. CONCLUSIONS: Patients with adenomatous polyps have low levels of micronutrient antioxidants in their colon mucosa. Because the serum levels of these antioxidants were similar in controls and polyp patients, our findings suggest an increased level of free radical activity in patients with polyps compared to normal subjects.

Adenomatous Polyps↗