Background
We performed a randomized controlled chemoprevention trial of oral leukoplakia by administrating a low dose of beta‐carotene and vitamin C supplements. 17% of subjects in the experimental ...arm (4/23) demonstrated clinical remission (complete or partial response) at completion of the trial. The objective of this study was to determine whether baseline expression of p53 and ki67 demonstrated any differences between those responding or not responding to our intervention. A secondary objective was to elucidate any relationship between dietary factors and clinical responses.
Methods
For this biomarker study, we included all subjects in the experimental group (n = 23) who were non‐smokers. Among 16 who completed the trial for 1 year of supplementation, there were four responders and 12 non‐responders at 1‐year follow‐up. Following immuno‐staining for p53 and ki67, the percentage of positive cell nuclei were analyzed as labeling index (LI).
Results
Expression of p53 was greater in basal layers than in para‐basal layers. Mean para‐basal LI of p53 was higher in non‐responding (26.0) than in responding subjects (11.2) (P = 0.028). ki67 LIs were not significantly different in the two groups.
Conclusions
Expression of p53 was inversely related to clinical response to the supplements. Other biomarkers that may recognize subject's responsiveness to chemoprevention require further study.
•Antioxidant and DNA damage protection potential studied.•Rosmarinic acid showed the best antioxidant activity.•Protective activity of ferulic acid was excellent on DNA.
In this study, ten different ...phenolic acids (caffeic, chlorogenic, cinnamic, ferulic, gallic, p-hydroxybenzoic, protocatechuic, rosmarinic, syringic, and vanillic acids) were evaluated for their antioxidant and DNA damage protection potentials. Antioxidant activity was evaluated by using four different test systems named as β-carotene bleaching, DPPH free radical scavenging, reducing power and chelating effect. In all test systems, rosmarinic acid showed the maximum activity potential, while protocatechuic acid was determined as the weakest antioxidant in β-carotene bleaching, DPPH free radical scavenging, and chelating effect assays. Phenolic acids were also screened for their protective effects on pBR322 plasmid DNA against the mutagenic and toxic effects of UV and H2O2. Ferulic acid was found as the most active phytochemical among the others. Even at the lowest concentration value (0.002 mg/ml), ferulic acid protected all of the bands in the presence of H2O2 and UV. It is followed by caffeic, rosmarinic, and vanillic acids. On the other hand, cinnamic acid (at 0.002 mg/ml), gallic acid (at 0.002 mg/ml), p-hydroxybenzoic acid (at 0.002 and 0.004 mg/ml), and protocatechuic acid (at 0.002 and 0.004 mg/ml) could not protect plasmid DNA.
UVA exposure induces DNA damage that could result in skin carcinogenesis. Antioxidants are usually employed as protective agents to avoid this problem: in particular, both β-carotene and α-tocopherol ...can protect the skin against UVA-induced damage. It is well known that the photochemical instability of these compounds has been a limiting factor for their applications to protect skin. In this study, stearyl ferulate-based solid lipid nanoparticles (SF-SLNs), as vehicles for β-carotene and α-tocopherol, were formulated to improve the stability of these compounds. The SF-SLNs were characterized for entrapment efficiency, size and shape together with their cytotoxicity and capability to inhibit lipid peroxidation. After treatment with a pro-oxidant and/or exposition to sunlight the antioxidants entrapped in SF-SLNs were extremely stable. The results highlighted how SF-SLNs represent a suitable vehicle for β-carotene and α-tocopherol stabilizing and protecting them from degradation. A dermatological formulation in order to prevent skin damages is, therefore, suggested.
This paper presents innovative packaging materials made of environmentally friendly biodegradable polymers (polylactide and polyhydroxybutyrate) with the addition of natural colorants commonly used ...in the food industry. Colorants fulfilled the role of indicator, changing colour under the influence of external factors, and gave the materials the characteristics of intelligent packaging, where colour changes indicated the life time of the materials. The paper gives the mechanical and thermal properties of the materials obtained, and describes changes in the colour of the samples under the influence of thermooxidation, UV and weathering, as well as the biodegradability of the materials. The packaging materials presented are in line with current trends in the packaging market and legal requirements. The samples, in addition to the basic functions of packaging materials, are pro-ecological and fully biodegradable new generation materials.
•Natural food colorants are indicator substances in biodegradable packaging.•Colorants change colour under the influence of external factors.•Change in the colour of the biodegradable packaging indicates its lifetime.
Key message
IbOr-R96H resulted in carotenoid overaccumulation and enhanced abiotic stress tolerance in transgenic sweetpotato calli.
The Orange (Or) protein is involved in the regulation of ...carotenoid accumulation and tolerance to various environmental stresses. Sweetpotato IbOr, with strong holdase chaperone activity, protects a key enzyme, phytoene synthase (PSY), in the carotenoid biosynthetic pathway and stabilizes a photosynthetic component, oxygen-evolving enhancer protein 2-1 (PsbP), under heat and oxidative stresses in plants. Previous studies of various plant species demonstrated that a single-nucleotide polymorphism (SNP) from Arg to His in Or protein promote a high level of carotenoid accumulation. Here, we showed that the substitution of a single amino acid at position 96 (Arg to His) of wild-type IbOr (referred to as IbOr-R96H) dramatically increases carotenoid accumulation. Sweetpotato calli overexpressing
IbOr
-
WT
or
IbOr
-
Ins
exhibited 1.8- or 4.3-fold higher carotenoid contents than those of the white-fleshed sweetpotato Yulmi (Ym) calli, and
IbOr
-
R96H
overexpression substantially increased carotenoid accumulation by up to 23-fold in sweetpotato calli. In particular, IbOr-R96H transgenic calli contained 88.4-fold higher levels of β-carotene than those in Ym calli. Expression levels of carotenogenesis-related genes were significantly increased in IbOr-R96H transgenic calli. Interestingly, transgenic calli overexpressing
IbOr
-
R96H
showed increased tolerance to salt and heat stresses, with similar levels of malondialdehyde to those in calli expressing
IbOr
-
WT
or
IbOr
-
Ins
. These results suggested that IbOr-R96H is a useful target for the generation of efficient industrial plants, including sweetpotato, to cope with growing food demand and climate change by enabling sustainable agriculture on marginal lands.
Model-based compartmental analysis of data on plasma retinol kinetics after administration of labeled retinol provides unique information about whole-body vitamin A metabolism. If labeled β-carotene ...is coadministered, its bioefficacy relative to the retinol reference dose can also be estimated.
The objectives were to model plasma retinol kinetics after administration of labeled preformed vitamin A and provitamin A β-carotene and to determine relative β-carotene bioefficacy.
We used the Simulation, Analysis and Modeling software (WinSAAM version 3.0.8; http://www.WinSAAM.org) to analyze previously collected data on plasma
C
- and
C
retinol kinetics for 14 d after oral administration of 1 mg
C
retinyl acetate and 2 mg
C
β-carotene in oil to 30 healthy young adults of European ancestry 13 men, 17 women; mean ± SD age: 24.5 ± 4.2 y; mean ± SD body weight: 65.2 ± 10 kg; mean ± SD body mass index (in kg/m
): 22.5 ± 1.9 with moderate vitamin A intakes.
A 6-component model provided the best fit to the data, including compartments for initial metabolism of vitamin A, plasma retinol, and extravascular vitamin A storage. The disposal rate was 6.7 ± 3.1 μmol/d, fractional catabolic rate was 6.0% ± 2.3%/d, and vitamin A stores were 123 ± 71 μmol. Relative β-carotene bioefficacy, based on the ratio of the areas under the fraction of dose curves calculated by WinSAAM, averaged 13.5% ± 6.02% (retinol activity equivalents = 7.7:1.0 μg). Interindividual variation in relative β-carotene bioefficacy was high (CV: 44%).
Vitamin A kinetics in these young adults were best described by essentially the same model that had been previously developed by using data for older adults with higher vitamin A stores; differences in parameter values reflected differences in vitamin A status. Estimated β-carotene bioefficacy was relatively low but similar to previously reported estimates obtained by graphical methods. This trial was registered at the UK Clinical Research Network as UKCRN 7413.
Background: The protective effects of antioxidant vitamins on hearing loss are well established in animal studies but in few human studies. Recent animal studies suggest that magnesium intake along ...with antioxidants may act in synergy to prevent hearing loss.Objective: We examined associations between intake of antioxidant vitamins (daily β-carotene and vitamins C and E) and magnesium and hearing thresholds and explored their joint effects in US adults.Design: We analyzed cross-sectional data from 2592 participants aged 20–69 y from NHANES 2001–2004. Hearing thresholds as pure tone averages (PTAs) at speech (0.5, 1, 2, and 4 kHz) and high frequencies (3, 4, and 6 kHz) were computed.Results: When examined individually, modeled as quartiles, and after adjustment for potential confounders, higher intakes of β-carotene, vitamin C, and magnesium were associated with lower (better) PTAs at both speech and high frequencies. High intakes of β-carotene or vitamin C combined with high magnesium compared with low intakes of both nutrients were significantly associated with lower (better) PTAs at high frequencies (−14.82%; 95% CI: −20.50% to −8.74% for β-carotene + magnesium and −10.72%; 95% CI: −16.57% to −4.45% for vitamin C + magnesium). The estimated joint effects were borderline significantly larger than the sums of the individual effects high β-carotene/low magnesium (−4.98%) and low β-carotene/high magnesium (−0.80%), P-interaction = 0.08; high vitamin C/low magnesium (−1.33%) and low vitamin C/high magnesium (2.13%), P-interaction = 0.09.Conclusion: Dietary intakes of antioxidants and magnesium are associated with lower risks of hearing loss.
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•The β-carotene was successfully encapsulated in CA and CAS microgels.•The introduction of SPI greatly improved encapsulation efficiency of CA microgels.•The effect of SPI during ...digestion was analyzed in detail by cryo-SEM.•The presence of SPI retarded the release of β-carotene in gastric.
In this study, the effects of soy protein isolate (SPI) on the morphology, encapsulation efficiency, storage stability, swelling behavior, and in vitro digestion behavior of calcium alginate (CA) microgels were investigated. CA and calcium alginate-SPI (CAS) microgels with encapsulated β-carotene were prepared by extruding a mixture of alginate and SPI using a co-extrusion technique, followed by cross-linking with Ca2+. All microgels exhibited homogeneous sizes and spherical shapes, and CAS microgels showed high levels of protein loading efficiency. The encapsulation efficiency and storage stability of β-carotene within CAS microgels were higher than those within CA microgels. The introduction of SPI into CAS microgels resulted in a higher degree of gel size shrinkage in gastric fluid and a lower degree of swelling in intestinal fluid compared to CA microgels. In vitro digestion was conducted to investigate the effects of the addition of SPI on the release behavior of CA and CAS microgels. Results obtained showed that CAS microgels were more resistant to simulated gastric fluid than CA microgels. Cryo-scanning electron microscopy (cryo-SEM) and confocal laser scanning microscopy (CLSM) observations indicated that the release behavior was dependent on the porosity of the CA and CAS microgels, and the porosity was influenced by the concentration of SPI. This study showed that the introduction of SPI to CA microgels can lead to the development of an effective controlled release delivery system.
•Purification of the human vitamin A forming enzyme BCMO1 in highly active monomeric form.•Characterization of the enzymatic properties of purified BCMO1.•Comparative analysis of membrane association ...properties of mammalian carotenoid cleavage oxygenase family members.•Characterization of BCMO1 as a soluble protein in cells and tissue.
The formal first step in in vitamin A metabolism is the conversion of its natural precursor β,β-carotene (C40) to retinaldehyde (C20). This reaction is catalyzed by the enzyme β,β-carotene-15,15′-monooxygenase (BCMO1). BCMO1 has been cloned from several vertebrate species, including humans. However, knowledge about this protein’s enzymatic and structural properties is scant. Here we expressed human BCMO1 in Spodoptera frugiperda 9 insect cells. Recombinant BCMO1 is a soluble protein that displayed Michaelis–Menten kinetics with a KM of 14μM for β,β-carotene. Though addition of detergents failed to increase BCMO1 enzymatic activity, short chain aliphatic detergents such as C8E4 and C8E6 decreased enzymatic activity probably by interacting with the substrate binding site. Thus we purified BCMO1 in the absence of detergent. Purified BCMO1 was a monomeric enzymatically active soluble protein that did not require cofactors and displayed a turnover rate of about 8 molecules of β,β-carotene per second. The aqueous solubility of BCMO1 was confirmed in mouse liver and mammalian cells. Establishment of a protocol that yields highly active homogenous BCMO1 is an important step towards clarifying the lipophilic substrate interaction, reaction mechanism and structure of this vitamin A forming enzyme.
Raman mapping is becoming a very useful tool in investigating cells and cellular components, as well as bioactive molecules intracellularly. In this study, we have encapsulated beta-carotene using a ...layer-by-layer technique, as a way to enhance its stability and bioavailability. Further, we have used Raman mapping to characterize the as-obtained capsules and monitor their uptake by the human retinal epithelial D407 cells. We were able to successfully map the beta-carotene distribution inside the capsules, to localize the capsules intracellularly, and distinguish between capsules and other cellular components.
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