Xanthophylls

叶黄素
  • 文章类型: Journal Article
    这项调查评估了膳食类胡萝卜素摄入量与超重/肥胖几率之间的关联。以及炎症/氧化应激生物标志物,851名超重/肥胖(BMI≥25kgm-2)参与者和754名正常体重对照者。采用124项食物频率问卷(FFQ)和食物成分数据库来估计类胡萝卜素的摄入量。二元逻辑回归评估类胡萝卜素摄入量与超重/肥胖几率的关联,调整几个潜在的混杂因素。多元线性回归模型揭示了类胡萝卜素摄入量与生物标志物之间的关联(人体测量学,血脂,炎症,抗氧化剂状态)。针对各种混杂因素和水果和蔬菜进行调整的Logistic回归模型显示出维生素A类胡萝卜素的保护性关联(即,β-胡萝卜素+α-胡萝卜素+β-隐黄质;比值比(OR):0.655,p=0.041)和虾青素(OR:0.859,p=0.017)。类似地调整的多重线性回归揭示了几种类胡萝卜素与较低水平的白细胞介素(IL)-6,IL-1β之间的显着关联。和TNF-α,并增加IL-10和总抗氧化能力。进一步分析显示,在针对各种混杂因素和蔬菜进行调整的模型中,番茄红素与超重/肥胖的几率增加显着相关(OR:1.595,p=0.032)(即,未经调整的水果)。发现维生素A类胡萝卜素和虾青素饮食摄入量的总和与超重/肥胖的几率之间存在保护性关联。发现番茄红素以外的类胡萝卜素与超重/肥胖的几率无关或呈负相关,这可能表明不同类胡萝卜素的作用或它们与不同食物组的关联。富含维生素A的食物,包括水果和蔬菜,似乎是减少炎症和超重/肥胖几率的谨慎策略。
    This investigation assessed associations between dietary carotenoid intake and the odds of overweight/obesity, as well as inflammatory/oxidative stress biomarkers, in 851 participants with overweight/obesity (BMI ≥25 kg m-2) and 754 normal-weight controls. A 124-item food-frequency-questionnaire (FFQ) and food composition databases were employed to estimate carotenoid intake. Binary logistic regressions assessed the association of carotenoid intake with the odds of overweight/obesity, adjusting for several potential confounders. Multiple linear regression models revealed associations between carotenoid intake and biomarkers (anthropometrics, blood lipids, inflammation, antioxidant status). Logistic regression models adjusted for various confounders and fruits and vegetables showed protective associations for provitamin A carotenoids (i.e., β-carotene + α-carotene + β-cryptoxanthin; odds ratio (OR): 0.655, p = 0.041) and astaxanthin (OR: 0.859, p = 0.017). Similarly adjusted multiple linear regressions revealed significant associations between several carotenoids and lower levels of interleukin (IL)-6, IL-1β, and TNF-α and increased IL-10 and total antioxidant capacity. Further analysis revealed that lycopene was significantly associated with increased odds of overweight/obesity (OR: 1.595, p = 0.032) in a model adjusted for various confounders and vegetables (i.e., unadjusted for fruits). A protective association between the sum of provitamin A carotenoid and astaxanthin dietary intake and the odds of having overweight/obesity was found. The findings that carotenoids other than lycopene were not or inversely associated with the odds of overweight/obesity may point toward differentiating effects of various carotenoids or their associations with different food groups. Provitamin A rich food items including fruits and vegetables appear to be a prudent strategy to reduce inflammation and the odds of having overweight/obesity.
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  • 文章类型: Journal Article
    小分子经常被用作染料,标记和标记,以可视化和探测细胞内的生物物理过程。然而,通常很少知道这种系统在细胞中时的光驱动激发态反应性。这里是一种实验方法,用于研究基准分子标记的ps时间分辨激发态动力学,虾青素,在活的人类细胞中引入。
    Small molecules are frequently used as dyes, labels and markers to visualize and probe biophysical processes within cells. However, very little is generally known about the light-driven excited-state reactivity of such systems when placed in cells. Here an experimental approach to study ps time-resolved excited state dynamics of a benchmark molecular marker, astaxanthin, in live human cells is introduced.
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  • 文章类型: Journal Article
    Winter evergreens living in mountainous areas have to withstand a harsh combination of high light levels and low temperatures in wintertime. In response, evergreens can activate a photoprotective process that consists of the downregulation of photosynthetic efficiency, referred to as winter photoinhibition (WPI). WPI has been studied mainly in woody evergreens and crops even when, in many instances, other functional groups such as lichens or bryophytes dominate in alpine and boreal habitats. Thus, we aimed to (1) assess the occurrence of WPI within overwintering evergreens comprising woody species, herbs, mosses and lichens, (2) compare the recovery kinetics among those groups and (3) clarify the role of thylakoid proteins and pigments in both processes: WPI and recovery. With this aim, WPI was analyzed in 50 species in the field and recovery kineticcs were studied in one model species from each functional group. Results showed that high levels of WPI are much more frequent among woody plants than in any other group, but are also present in some herbs, lichens and mosses. Winter conditions almost always led to the de-epoxidation of the xanthophyll cycle. Nevertheless, changes in the de-epoxidation level were not associated with the activation/deactivation of WPI in the field and did not match changes in photochemical efficiency during recovery treatments. Seasonal changes in thylakoid proteins [mainly D1 (photosystem II core complex protein) and PsbS (essential protein for thermal dissipation)] were dependent on the functional group. The results highlight the diversity of physiological solutions and suggest a physical-mechanical reason for the more conservative strategy of woody species compared with other groups.
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  • 文章类型: Journal Article
    耐脱水的植物能够承受脱水并在再水化后恢复正常的代谢功能。这些植物可以脱水,直到它们的细胞质进入“玻璃态”,其中分子迁移率严重降低。在耐干燥的种子中,寿命可以通过干燥和降低储存温度来提高。在这些条件下,它们仍然缓慢恶化,但不知道恶化过程是否包括酶活性。光合生物的储存稳定性研究较少,没有关于光合组织玻璃态的报道。这里,耐干燥苔藓在75%或<5%相对湿度下脱水,导致缓慢(SD)或快速干燥(RD),分别,和不同的干燥组织的残余水含量。通过动态机械热分析评估了干苔藓中的分子迁移率,表明在室温下只有快速干燥的样品进入玻璃态,而缓慢干燥的样品处于“橡胶状”状态。紫黄质循环活动,质体的积累,在SD上观察到类囊体的重组,但不是RD。紫黄质循环活性关键取决于紫黄质去环氧酶(VDE)的活性。因此,提出酶活性发生在橡胶态(SD后),并且在玻璃态(RD后)没有VDE活性是可能的。此外,有证据表明,玉米黄质在恢复中具有一定的作用,显然与其在叶绿素荧光的非光化学猝灭中的作用无关。
    Desiccation-tolerant plants are able to withstand dehydration and resume normal metabolic functions upon rehydration. These plants can be dehydrated until their cytoplasm enters a \'glassy state\' in which molecular mobility is severely reduced. In desiccation-tolerant seeds, longevity can be enhanced by drying and lowering storage temperature. In these conditions, they still deteriorate slowly, but it is not known if deteriorative processes include enzyme activity. The storage stability of photosynthetic organisms is less studied, and no reports are available on the glassy state in photosynthetic tissues. Here, the desiccation-tolerant moss Syntrichia ruralis was dehydrated at either 75% or <5% relative humidity, resulting in slow (SD) or rapid desiccation (RD), respectively, and different residual water content of the desiccated tissues. The molecular mobility within dry mosses was assessed through dynamic mechanical thermal analysis, showing that at room temperature only rapidly desiccated samples entered the glassy state, whereas slowly desiccated samples were in a \'rubbery\' state. Violaxanthin cycle activity, accumulation of plastoglobules, and reorganization of thylakoids were observed upon SD, but not upon RD. Violaxanthin cycle activity critically depends on the activity of violaxanthin de-epoxidase (VDE). Hence, it is proposed that enzymatic activity occurred in the rubbery state (after SD), and that in the glassy state (after RD) no VDE activity was possible. Furthermore, evidence is provided that zeaxanthin has some role in recovery apparently independent of its role in non-photochemical quenching of chlorophyll fluorescence.
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  • 文章类型: Journal Article
    This work reports on the composition and bionutritional value of organic virgin olive oil from the Nocellara del Belice variety, one cultivated in the olive areas of the Sicily region, Italy. Destoned oils obtained by processing olives with a destoning-based procedure were compared with conventional oils. This innovative technique, consisting in removing the stone from fruits prior to processing, strongly enhanced the already high-quality level of the conventional product. An in-depth analytical investigation from 2008 to 2010 showed how this innovative olive extraction process led to an excellent peculiar final product, mainly attributable to the improved biophenol and volatile composition, as well as higher concentrations of the lipophilic and vitamin antioxidants (tocopherols and tocotrienols). It had higher levels of oleocanthal (p-HPEA-EDA), a nutraceutical compound exerting actions against COX1 and COX2 (cycloxygenases). Its head-space aroma displayed new volatile phytomolecules and also had higher levels of green volatiles from the lipoxygenase (LOX)-pathway (one having as precursors the polyunsaturated fatty acids containing a cis-cis-1,4-pentadiene system). Among the other bioactives, we highlight its significant levels of trans-β-carotene and xanthophylls (lutein, violaxanthin, neoxanthin and other carotenoids). Its enhanced nutritional value was also attributable to the increased intensity of valuable tasting notes.
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  • 文章类型: Journal Article
    BACKGROUND: The xanthophyll carotenoids lutein (L) and zeaxanthin (Z) are found in and around the macula of the primate retina, where they are termed macular pigment (MP). Dietary L and Z are absorbed with fat in the gut and transported on lipoproteins to the retina. Both MP and serum lipoproteins have been related to risk for neurodegenerative diseases such as age-related macular degeneration (AMD). L and Z are carried on both HDL (related to reduced risk of AMD) and LDL (related to increased risk). The purpose of this set of studies was to analyze the relation between L and Z in the serum and retina with the circulating lipid profile.
    METHODS: In all experiments, lipoproteins were measured enzymatically from plasma, and MP optical density (MPOD) was measured using customized heterochromatic flicker photometry. Experiment 1: Relations between serum L and Z, MPOD and lipoprotein levels. 108 young, healthy subjects (M = 23.2, SD = 4.12 years) participated. Lipoprotein levels and MPOD were measured. In a subset of 66 participants, serum L and Z levels were also measured using high-performance liquid chromatography. Experiment 2: Relations between lipoprotein levels and MPOD in statin users. 20 subjects (M = 58.05, SD = 11.08 years) taking statin medication and 20 subjects (M = 57.95, SD = 11.03 years) not taking satin were recruited for participation. MPOD and lipoprotein levels were measured. Experiment 3: lowering lipoprotein levels to impact MPOD. One individual (aged 41 years) with high MP density adhered first to an atorvastatin regimen, then, after a wash-out period, to a rosuvastatin regimen.
    RESULTS: Experiment 1: HDL were significantly (p < 0.05) related to MPOD (r = 0.33), to serum L (r = 0.36) and to serum Z (r = 0.26). MPOD was also significantly related to total cholesterol (r = 0.19). Experiment 2: MPOD was not lower in statin users when compared to matched non-statin users, but MPOD decreased significantly with increased duration of statin use (r = -0.63). Experiment 3: Administration of a statin regimen reduced MPOD with atorvastatin (p < 0.05) but not with rosuvastatin.
    CONCLUSIONS: Serum xanthophylls, retinal xanthophylls and lipoprotein concentrations are significantly related, and changing lipoprotein levels may impact levels of retinal xanthophylls.
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  • 文章类型: Journal Article
    背景:在紫黄质(V)循环中,当强光或与其他应激源结合的光导致光系统的过度激发时,V被去环氧化为玉米黄质(Z)。然而,植物在黑暗中也会遭受压力,最近的报道表明,脱水会在没有光的情况下引发V-去环氧化。在这项研究中,我们使用高度耐受胁迫的褐藻Pelvetiacanaliculata作为模型生物,由于它缺乏叶黄素和它的非光化学猝灭独立于跨囊体-ΔpH,研究由非生物应激源诱导的黑暗中V循环的触发。
    结果:我们已经表明,除了干燥,其他因素,如浸泡,缺氧和高温也会在黑暗中引起V-de环氧化。一旦治疗停止,这个过程是可逆的(除了加热,造成致命损害)。不考虑施加的压力,产生的去环氧化叶黄素与Fv/Fm的降低相关,表明在光合效率的下调中具有共同的功能。还研究了塑性醌池的氧化还原态和V循环酶对黑暗中V-去环氧化的差异活性的含义。目前的结果表明,即使在黑暗中,紫黄质去环氧酶(VDE)和玉米黄质-环氧酶(ZE)也具有基本的组成活性,在压力下被ZE抑制。这种抑制导致Z积累。
    结论:这项研究表明,即使在绝对没有光的情况下,V周期活动也是由几种非生物应激源触发的。导致Fv/Fm降低。这一发现为了解V循环的调节机制及其生态生理作用提供了新的见解。
    BACKGROUND: In the violaxanthin (V) cycle, V is de-epoxidized to zeaxanthin (Z) when strong light or light combined with other stressors lead to an overexcitation of photosystems. However, plants can also suffer stress in darkness and recent reports have shown that dehydration triggers V-de-epoxidation in the absence of light. In this study, we used the highly stress-tolerant brown alga Pelvetia canaliculata as a model organism, due to its lack of lutein and its non-photochemical quenching independent of the transthylakoidal-ΔpH, to study the triggering of the V-cycle in darkness induced by abiotic stressors.
    RESULTS: We have shown that besides desiccation, other factors such as immersion, anoxia and high temperature also induced V-de-epoxidation in darkness. This process was reversible once the treatments had ceased (with the exception of heat, which caused lethal damage). Irrespective of the stressor applied, the resulting de-epoxidised xanthophylls correlated with a decrease in Fv/Fm, suggesting a common function in the down-regulation of photosynthetical efficiency. The implication of the redox-state of the plastoquinone-pool and of the differential activity of V-cycle enzymes on V-de-epoxidation in darkness was also examined. Current results suggest that both violaxanthin de-epoxidase (VDE) and zeaxanthin-epoxidase (ZE) have a basal constitutive activity even in darkness, being ZE inhibited under stress. This inhibition leads to Z accumulation.
    CONCLUSIONS: This study demonstrates that V-cycle activity is triggered by several abiotic stressors even when they occur in an absolute absence of light, leading to a decrease in Fv/Fm. This finding provides new insights into an understanding of the regulation mechanism of the V-cycle and of its ecophysiological roles.
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  • 文章类型: Journal Article
    Desiccation-tolerance ability in photosynthetic organisms is largely based on a battery of photoprotective mechanisms. Xanthophyll cycle operation induced by desiccation in the absence of light has been previously proven in the desiccation-tolerant fern Ceterach officinarum. To understand the physiological function of xanthophyll cycle induction in darkness and its implication in the desiccation tolerance in more detail, we studied its triggering factors and its photochemical effects in the lichen Lobaria pulmonaria. We found that both the drying rate and the degree of desiccation play a crucial role in the violaxanthin de-epoxidase activation. De-epoxidation of violaxanthin to zeaxanthin (Z) occurs when the tissue has lost most of its water and only after slow dehydration, suggesting that a minimum period of time is required for the enzyme activity induction. Fluorescence analysis showed that Z, synthesised during tissue dehydration in the absence of light, prevents photoinhibition when rewatered tissues are illuminated. This is probably due to Z implication in both non-photochemical quenching and/or antioxidative responses.
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  • 文章类型: Journal Article
    Carotenoids possess antioxidant properties and thus may protect against prostate cancer. Epidemiological studies of dietary carotenoids and this malignancy were inconsistent, partially due to dietary assessment error. In this study, we aimed to investigate the relation between plasma concentrations of carotenoids and the risk of prostate cancer in a population-based case-control study in Arkansas. Cases (n = 193) were men with prostate cancer diagnosed in 3 major hospitals, and controls (n = 197) were matched to cases by age, race, and county of residence. After adjustment for confounders, plasma levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin were inversely associated with prostate cancer risk. Subjects in the highest quartile of plasma lycopene (513.7 microg/l) had a 55% lower risk of prostate cancer than those in the lowest quartile (140.5 microg/l; P trend = 0.042). No apparent association was observed for plasma alpha-carotene and beta-carotene. Further adjustment for the other 4 carotenoids did not materially alter the risk estimates for plasma lycopene, lutein/zeaxanthin, and beta-cryptoxanthin but appeared to result in an elevated risk with high levels of plasma alpha-carotene and beta-carotene. The results of all analyses did not vary substantially by age, race, and smoking status. This study added to the emerging evidence that high circulating levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin are associated with a low risk of prostate cancer.
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  • 文章类型: Journal Article
    OBJECTIVE: To evaluate the relationship of dietary carotenoids, vitamin A, alpha-tocopherol, and vitamin C with prevalent age-related macular degeneration (AMD) in the Age-Related Eye Disease Study (AREDS).
    METHODS: Demographic, lifestyle, and medical characteristics were ascertained on 4519 AREDS participants aged 60 to 80 years at enrollment. Stereoscopic color fundus photographs were used to categorize participants into 4 AMD severity groups and a control group (participants with < 15 small drusen). Nutrient intake was estimated from a self-administered semiquantitative food frequency questionnaire at enrollment. Intake values were energy adjusted and classified by quintiles. The relationship between diet and AMD status was assessed using logistic regression analyses.
    RESULTS: Dietary lutein/zeaxanthin intake was inversely associated with neovascular AMD (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.45-0.93), geographic atrophy (OR, 0.45; 95% CI, 0.24-0.86), and large or extensive intermediate drusen (OR, 0.73; 95% CI, 0.56-0.96), comparing the highest vs lowest quintiles of intake, after adjustment for total energy intake and nonnutrient-based covariates. Other nutrients were not independently related to AMD.
    CONCLUSIONS: Higher dietary intake of lutein/zeaxanthin was independently associated with decreased likelihood of having neovascular AMD, geographic atrophy, and large or extensive intermediate drusen.
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