Search results for "beta carotene"

Immune activation rapidly mirrored in a secondary sexual trait.

2003

A crucial assumption underlying most models of sexual selection is that sexual advertisements honestly reflect the phenotypic and/or genetic quality of their bearers ([1][1]). Here we show that experimental activation of the immune system is rapidly mirrored in the expression of a carotenoid-based

?-Carotene Supplements Cannot Meet All Vitamin A Requirements of Vitamin A-Deficient Rats

1993

Effect of a two-year supplementation with low doses of antioxidant vitamins and/or minerals in elderly subjects on levels of nutrients and antioxidan…

1997

Eighty-one elderly hospitalized subjects (65 years) were recruited for a double-blind placebo-controlled study to examine low dose supplementation of antioxidant vitamins and minerals on biological and functional parameters of free radical metabolism. Subjects were randomly assigned to one of the four treatment groups, daily receiving for 2 years: placebo group; mineral group: 20 mg zinc, 100 micrograms selenium; vitamin group: 120 mg vitamin C (Vit C), 6 mg beta-carotene (beta CA), 15 mg vitamin E (Vit E); mineral and vitamin group: Zn 20 mg, Se 100 micrograms, Vit C 120 mg, beta CA 6 mg, Vit E 15 mg.Fifty-seven subjects completed the study. A large frequency of Vit C, Zn and Se deficienci…

Effects of β-Carotene, Retinal, Riboflavin, α-Tocopherol and Vitamins C and K1 on Sister-chromatid Exchanges Induced by 3-Amino-1-methyl-5H-pyrido[4,…

1998

The vitamins and related compounds cited in the title were investigated for their abilities to modulate sister-chromatid exchanges (SCEs) induced by Trp-P-2 or cyclophosphamide (CP) in human peripheral lymphocyte cultures in the presence of an exogenous metabolizing system from rat liver. When inducer and test substances were given simultaneously, beta-carotene, retinal and alpha-tocopherol caused a dose-dependent decrease of SCE frequencies induced by Trp-P-2 and CP. Vitamin K1, however, brought about an identical effect with Trp-P-2 only, while with CP an initial decrease of SCEs was followed by a statistically significant re-increase at higher concentrations. Vitamin C was ineffective ag…

Inverse association of vitamin C with cataract in older people in India.

2011

OBJECTIVE: To examine the association between vitamin C and cataract in the Indian setting. DESIGN: Population-based cross-sectional analytic study. PARTICIPANTS: A total of 5638 people aged ≥60 years. METHODS: Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants wer…

Is obesity associated with oxidative stress in children?

2009

We evaluated the presence of oxidative stress in obese children without co-morbidities.The study population included 68 children (30 girls, 38 boys), between 6 and 14 years of age. The levels of markers of oxidative damage (malondialdehyde [MDA], and plasma carbonyl groups [CG]) and measures of antioxidant defense, such as the enzyme glutathione peroxidase (GPx) and low molecular scavengers (erythrocyte-reduced glutathione [GSH], alpha-tocopherol and beta-carotene) were determined. Children were categorized in groups by the standard deviation score of body mass index (SDS-BMI). Twenty children were non-obese (SDS-BMIor =1.33), and the 48 obese children (SDS-BMIor =2) were further divided in…

Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus.

2009

Codoner-Franch P, Pons-Morales S, Boix-Garcia L, Valls-Belles V. Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus. Background: Type 1 diabetes (T1D) mellitus and obesity are recognized risk factors for cardiovascular disease (CVD). A common mechanism underlying an increased risk for endothelial dysfunction in these two metabolic diseases is oxidative stress. Objective: To evaluate and compare the oxidant/antioxidant defense systems in children affected with T1D or obesity in order to determine the importance of oxidative stress before the emergence of complications. Subjects: Children with T1D (n = 20) or obesity (n = 22), without com…

A lycopene β-cyclase/lycopene ε-cyclase/light-harvesting complex-fusion protein from the green algaOstreococcus lucimarinuscan be modified to produce…

2015

Summary Biosynthesis of asymmetric carotenoids such as α-carotene and lutein in plants and green algae involves the two enzymes lycopene β-cyclase (LCYB) and lycopene e-cyclase (LCYE). The two cyclases are closely related and probably resulted from an ancient gene duplication. While in most plants investigated so far the two cyclases are encoded by separate genes, prasinophyte algae of the order Mamiellales contain a single gene encoding a fusion protein comprised of LCYB, LCYE and a C-terminal light-harvesting complex (LHC) domain. Here we show that the lycopene cyclase fusion protein from Ostreococcus lucimarinus catalyzed the simultaneous formation of α-carotene and β-carotene when heter…

Strong coupling between surface plasmon polaritons and β-carotene in nanolayered system.

2013

In this article we experimentally demonstrate the strong coupling between surface plasmon polaritons (SPP) and the S(2) state of β-carotene. The SPPs are excited by prism coupling technique on a thin silver film with β-carotene embedded in a polymer layer on top of that. Rabi splittings with energies 80 and 130 meV are observed in the recorded dispersion relations. Both coupled oscillator model and transfer matrix method are used to fit the experimental results. The scattered radiation of the propagating strongly coupled SPP-S(2) hybrids is collected and an increase of the low energy splitting to 120 meV is observed compared to the reflectivity data. In addition, we performed molecule excit…

Studies on the antioxidant activity of the essential oil and extract of Tunisian Tetraclinis articulata (Vahl) Mast. (Cupressaceae).

2013

This study analyses the chemical composition and in vitro antioxidant activity of both the essential oil and the 80% aqueous acetone extract of Tetraclinis articulata leaves. The GC-MS analysis of the essential oil identified 66 components that comprise 93.5% of the oil. The major constituents of the oil are: bornyl acetate (31.4%), α-pinène (24.5%) and camphor (20.3%). Antioxidant activities of the samples were determined using four different test systems, namely DPPH, β-carotene/linoleic acid, reducing power and metal chelating activity assay. Test results from the DPPH system showed the strongest radical scavenging activity was exhibited by the 80% aqueous acetone extract (IC(50) = 5.5 µ…