Antioxidant and prooxidant roles for beta-carotene, alpha-tocopherol and ascorbic acid in human lung cells

Different effects of dietary β-hydroxy-β-methylbutyrate on composition of fatty acid and free amino acid, and fatty metabolism in the different muscles of broilers

In the study, 336 broiler chickens were selected to explore dietary effects of different β-hydroxy-β-methylbutyrate (HMB) levels (0 (control), 0.05, 0.10, and 0.15%) on the compositions of fatty acids and free amino acids, and lipid metabolism in the different muscles of broilers. In the breast muscle, dietary HMB supplementation hardly affected the free amino acid composition (P > 0.05). Compared to the control group, dietary 0.10 and 0.15% HMB supplementation decreased the content of C18:1n9c and thus the monounsaturated fatty acid (MUFA), and dietary 0.15% HMB supplementation increased the sum of saturated fatty acids (SFA) (P < 0.05). Moreover, compared to the control group, dietary 0.05 and 0.10% HMB increased the mRNA expression of proliferator activated receptor-γ and the activity of fatty acid synthase (FAS), and dietary 0.10% HMB increased the acetyl-CoA carboxylase activity (P < 0.05). In the leg muscle, dietary 0.10 and 0.15% HMB increased the MUFA content and decreased the polyunsaturated fatty acid (PUFA) content, the PUFA to SFA ratio, the mRNA expression of sterol regulatory element binding proteins-1c, and the activities of acyl-CoA oxidase 1 and acetyl-CoA synthetase (P < 0.05). Moreover, dietary 0.10% HMB decreased the activities of hydroxy-3-methylglutaryl-CoA synthase 1 and FAS in comparison to the control group (P < 0.05). Dietary 0.05% HMB decreased the contents of essential amino acids and nonessential amino acids (NEAA), and dietary 0.15% HMB decreased the NEAA content (P < 0.05). In summary, dietary 0.10% HMB supplementation had superior efficiency on lipogenesis in the breast muscle of broilers. However, dietary HMB supplementation, especially at the level of 0.05 and 0.15%, decreased meat nutritional values and the lipogenesis in leg muscles.

Ascorbic Acid (Vitamin C) as a Cosmeceutical to Increase Dermal Collagen for Skin Antiaging Purposes: Emerging Combination Therapies

Ascorbic acid (AA) is an essential nutrient and has great potential as a cosmeceutical that protects the health and beauty of the skin. AA is expected to attenuate photoaging and the natural aging of the skin by reducing oxidative stress caused by external and internal factors and by promoting collagen gene expression and maturation. In this review, the biochemical basis of AA associated with collagen metabolism and clinical evidence of AA in increasing dermal collagen and inhibiting skin aging were discussed. In addition, we reviewed emerging strategies that have been developed to overcome the shortcomings of AA as a cosmeceutical and achieve maximum efficacy. Because extracellular matrix proteins, such as collagen, have unique amino acid compositions, their production in cells is influenced by the availability of specific amino acids. For example, glycine residues occupy 1/3 of amino acid residues in collagen protein, and the supply of glycine can be a limiting factor for collagen synthesis. Experiments showed that glycinamide was the most effective among the various amino acids and amidated amino acids in stimulating collagen production in human dermal fibroblasts. Thus, it is possible to synergistically improve collagen synthesis by combining AA analogs and amino acid analogs that act at different stages of the collagen production process. This combination therapy would be useful for skin antiaging that requires enhanced collagen production.

Redox biomarkers in dietary interventions and nutritional observation studies - From new insights to old problems

Purpose

The purpose of this review is to give an overview on recently published articles investigating the associations of diet and dietary interventions with biomarkers of oxidative stress with special emphasis on different categories of redox biomarkers.

Findings

Intervention and observational studies both in healthy participants and patients that investigated associations of dietary habits, foodstuffs or isolated nutrients with biomarkers of oxidative stress were included in this review. Recently published observation studies confirm the inverse association between fruit and vegetable intake and oxidative stress markers. Studies investigating the effect of vitamin D and vitamin E, magnesium, zinc, chromium, selenium, probiotic supplementation and several phytochemicals reported consistent changes in redox biomarkers. Of 88 articles included in this review, only seven studies measured biomarkers from the three categories: oxidative damage, endogenous antioxidants, and exogenous antioxidants. Many studies rely on controversial assays for total antioxidant capacity, thus there is potential in many studies to improve biomarker repertoire to cover all three categories of biomarkers and to turn away from such assays.

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Oxidative stress can be assessed by specific biomarker categories.

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Three biomarker categories: oxidative damage, endogenous, exogenous antioxidants.

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Only seven studies performed measurements of all three biomarker categories.

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TAC, TRAP, FRAP, ORAC should not be used as stand-alone redox marker.

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Several interventions reported improvements in markers of oxidative stress.

Interactions between free and bound antioxidants under different conditions in food systems

This review aimed to give comprehensive information about the interactions between free and bound antioxidants naturally found in different food matrices. In this context, firstly, the free and bound antioxidant terms are defined; their place in the daily diet, the path they follow in the body and their characteristics are explained. Factors affecting the interactions have been revealed as a result of the compilation of studies conducted until today, related to bound and free antioxidant interactions. Accordingly, it was observed that many factors such as reaction environment, concentration, pH, chemical structure, source and antioxidant/prooxidant nature of the compounds were effective on interactions. It has been emphasized that the interactions between free and bound antioxidants have a dynamic balance that can easily change under the influence of various factors, which in turn needs the interactions to be handled specifically for each case.

The biology of ergothioneine, an antioxidant nutraceutical

Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.

Quantification of Carotenoids, α-Tocopherol, and Ascorbic Acid in Amber, Mulligan, and Laird's Large Cultivars of New Zealand Tamarillos (Solanum betaceum Cav.)

Amber (yellow), Laird's Large (red) and Mulligan (purple-red) cultivars of New Zealand tamarillo fruit were separated into pulp (endo- and mesocarp) and peel (exocarp), and analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) for carotenoids, α-tocopherol and ascorbic acid contents. Fresh Mulligan pulp had the highest content of β-carotene (0.9 mg/100 g), α-tocopherol (1.9 mg/100 g), and ascorbic acid (28 mg/100 g). Higher concentrations of β-carotene and ascorbic acid, and lower concentrations of α-tocopherol were detected in pulps compared with peels. Compared with standard serves of other fruit, tamarillo had the highest β-carotene (9-20% RDI (recommended dietary intake)/serve), high ascorbic acid (67-75% RDI/serve), and α-tocopherol (16-23% adequate intake/serve). All cultivars had diverse carotenoid profiles dominated by provitamin A carotenoids (β-carotene and β-cryptoxanthin) and xanthophyll carotenoids (lutein; zeaxanthin and antheraxanthin). Favorable growth conditions (high light intensity and low temperature) may explain the higher antioxidant vitamin content in New Zealand tamarillos compared to those from other countries. Tamarillo peels may be used as natural food coloring agent to reduce waste and deliver sustainable production.

Cytotoxic Activity of Christia vespertilionis Root and Leaf Extracts and Fractions against Breast Cancer Cell Lines

Christia vespertilionis, commonly known as 'Daun Rerama', has recently garnered attention from numerous sources in Malaysia as an alternative treatment. Its herbal decoction was believed to show anti-inflammatory and anti-cancer effects. The present study investigated the cytotoxicity of the extract of root and leaf of C. vespertilionis. The plant parts were successively extracted using the solvent maceration method. The most active extract was further fractionated to afford F1-F8. The cytotoxic effects were determined using MTT assay against human breast carcinoma cell lines (MCF-7 and MDA-MB-231). The total phenolic content (TPC) of the extracts were determined. The antioxidant properties of the extract were also studied using DPPH and β-carotene bleaching assays. The ethyl acetate root extract demonstrated selective cytotoxicity especially against MDA-MB-231 with the highest TPC and antioxidant properties compared to others (p < 0.05). The TPC and antioxidant results suggest the contribution of phenolic compounds toward its antioxidant strength leading to significant cytotoxicity. F3 showed potent cytotoxic effects while F4 showed better antioxidative strength compared to others (p < 0.05). Qualitative phytochemical screening of the most active fraction, F3, suggested the presence of flavonoids, coumarins and quinones to be responsible toward the cytotoxicity. The study showed the root extracts of C. vespertilionis to possess notable anti-breast cancer effects.

Fucoxanthin for Topical Administration, a Phototoxic vs. Photoprotective Potential in a Tiered Strategy Assessed by In Vitro Methods

Fucoxanthin possesses a well-described antioxidant activity that might be useful for human skin photoprotection. However, there is a lack of scientific information regarding its properties when applied onto human skin. Thus, the objective of the present study was to assess the photoprotective and phototoxicity potential of fucoxanthin based on its ultraviolet (UVB 280-320 nm; UVA 320-400 nm) and visible (VIS 400-700 nm) absorption, photostability, phototoxicity in 3T3 mouse fibroblast culture vs. full-thickness reconstructed human skin (RHS), and its ability to inhibit reactive oxygen species formation that is induced by UVA on HaCaT keratinocytes. Later, we evaluated the antioxidant properties of the sunscreen formulation plus 0.5% fucoxanthin onto RHS to confirm its bioavailability and antioxidant potential through the skin layers. The compound was isolated from the alga Desmarestia anceps. Fucoxanthin, despite presenting chemical photo-instability (dose 6 J/cm2: 35% UVA and 21% VIS absorbance reduction), showed acceptable photodegradation (dose 27.5 J/cm2: 5.8% UVB and 12.5% UVA absorbance reduction) when it was added to a sunscreen at 0.5% (w/v). In addition, it increased by 72% of the total sunscreen UV absorption spectra, presenting UV-booster properties. Fucoxanthin presented phototoxic potential in 3T3 fibroblasts (mean photo effect 0.917), but it was non-phototoxic in the RHS model due to barrier function that was provided by the stratum corneum. In addition, it showed a significant inhibition of ROS formation at 0.01% (p < 0.001), in HaCat, and in a sunscreen at 0.5% (w/v) (p < 0.001), in RHS. In conclusion, in vitro results showed fucoxanthin protective potential to the skin that might contribute to improving the photoprotective potential of sunscreens in vivo.

Radioprotective effects of vitamin A against gamma radiation in mouse bone marrow cells

Radioprotectors by neutralizing the effects of free radicals, reduce the destructive effects of radiation. In this protocol article, the radioprotectory effect of vitamin A on micronuclei induced by gamma radiation was evaluated using micronucleus test. Vitamin A was injected intraperitoneally at 100 and 400 mg/kg two hours before 2 Gray (Gy) of gamma radiation. Animals were sacrificed after 24 h, and then specimens of the bone marrow were smeared and stained. The number of micronuclei were counted in polychromatic cells. Both dosage of vitamin A reduced the micronucleus in bone marrow polychromatic erythrocytes (MnPCE) level, which is statistically significant. The appropriate amount of vitamin A for protection in mice is 100 mg/kg, which protect the bone marrow of mice against clastogenic effects of radiation. The results of the study showed that vitamin A, possibly with an antioxidant mechanism, eliminates the effects of free radicals from ionizing radiation on bone marrow cells and reduces genetic damage. •The data of radioprotective effects of vitamin A showed that administration of 100 mg/kg vitamin A to mice prior to 2 Gy of gamma radiation has reduced the micronucleus levels in PCE cells by a factor of 2.62.•Administration of 100 mg/kg vitamin A, which is much smaller than LD50 of vitamin A (LD50 for intraperitoneal injection = 1510 ± 240 mg/kg) can protect mice.•Vitamin A reduces the harmful effects of ionizing radiation on DNA, due to the antioxidant activity and the trapping of free radicals produced by radiation, and diminish the genetic damage caused by radiation.•Vitamin A has no effect on the proliferation and differentiation rate of bone marrow cells.

Significant metabolic improvement by a water extract of olives: animal and human evidence

PURPOSE

Dyslipidemia and impaired glucose metabolism are the main health issues of growing prevalence and significant high healthcare cost, requiring novel prevention and/or therapeutic approaches. Epidemiological and animal studies revealed that olive oil is an important dietary constituent, inducing normolipidemia. However, no studies have specifically investigated the polyphenol-rich water extract of olives (OLWPE), generated during olive oil production.

METHODS

In the present work, we initially examined the effect of OLPWE on animals' metabolic parameters. Rats fed with a high-fat diet were treated with three different doses of OLPWE for 4 months. Additionally, bioavailability was explored. Afterwards, OLWPE's metabolic effect was explored in humans. Healthy volunteers consumed microencapsulated OLWPE for 4 weeks, in a food matrix [one portion (30 g) of a meat product].

RESULTS

High-fat-fed rats developed a metabolic dysfunction, with increased LDL and insulin levels and decreased HDL; this syndrome was significantly impaired when treated with OLWPE. Treated rats had increased total plasma antioxidant capacity, while several phenolic compounds were detected in their blood. These findings were also verified in humans that consumed OLWPE, daily, for 4 weeks. Interestingly, in individuals with elements of cardio-metabolic risk, OLWPE consumption resulted in reduced glucose, insulin, total cholesterol, LDL and oxLDL levels.

CONCLUSIONS

Our data clearly show that OLWPE can improve glucose and lipid profile, indicating its possible use in the design of functional food and/or therapeutic interventions.

Mechanisms enhancing the protective functions of macular xanthophylls in the retina during oxidative stress

Macular xanthophylls (MXs) are distinguished from other dietary carotenoids by their high membrane solubility and preferential transmembrane orientation. Additionally, these properties enhance the chemical and physical stability of MXs in the eye retina, and maximize their protective activities. The effectiveness of MXs' protection is also enhanced by their selective accumulation in the most vulnerable domains of retinal membranes. The retina is protected by MXs mainly through blue-light filtration, quenching of the excited triplet states of potent photosensitizers, and physical quenching of singlet oxygen. To perform these physical, photo-related actions, the structure of MXs should remain intact. However, the conjugated double-bond structure of MXs makes them highly chemically reactive and susceptible to oxidation. Chemical quenching of singlet oxygen and scavenging of free radicals destroy their intact structure and consume MXs. Consequently, their physical actions, which are critical to the protection of retina, are diminished. Thus, it is timely and important to identify mechanisms whereby the chemical destruction (bleaching) of MXs in retinal membranes can be reduced. It was shown that nitroxide free radicals (spin labels) located in membranes protect MXs against destruction, and their effect is especially pronounced during the light-induced formation of singlet oxygen. That should extend and enhance their positive action in the retina through physical processes. In this review, we will discuss possible applications of this new strategy during ophthalmological procedures, which can cause acute bleaching of MXs and damage the retina through oxidative processes.

Role of Zucchini and Its Distinctive Components in the Modulation of Degenerative Processes: Genotoxicity, Anti-Genotoxicity, Cytotoxicity and Apoptotic Effects

Zucchini (Cucurbita pepo subsp. pepo) is a seasonal vegetable with high nutritional and medical values. Many useful properties of this fruit are attributed to bioactive compounds. Zucchini fruits ("Yellow" and "Light Green" varieties) and four distinctive components (lutein, β-carotene, zeaxanthin and dehydroascorbic acid) were selected. Firstly, the lutein, β-carotene, zeaxanthin and dehydroascorbic acid contents were determined in these fruits. Then, in order to evaluate the safety and suitability of their use, different assays were carried out: (i) genotoxicity and anti-genotoxicity tests to determine the safety and DNA-protection against hydrogen peroxide; (ii) cytotoxicity; and (iii) DNA fragmentation and Annexin V/PI (Propidium Iodide) assays to evaluate the pro-apoptotic effect. Results showed that: (i) all the substances were non-genotoxic; (ii) all the substances were anti-genotoxic except the highest concentration of lutein; (iii) "Yellow" zucchini epicarp and mesocarp exhibited the highest cytotoxic activity (IC50 > 0.1 mg/mL and 0.2 mg/mL, respectively); and (iv) "Light Green" zucchini skin induced internucleosomal DNA fragmentation, β-carotene being the possible molecule responsible for its pro-apoptotic activity. To sum up, zucchini fruit could play a positive role in human health and nutrition due to this fruit and its components were safe, able to inhibit significantly the H₂O₂-induced damage and exhibit anti-proliferative and pro-apoptotic activities toward HL60 (human promyelocytic leukemia cells) tumor cells. The information generated from this research should be considered when selecting potential accessions for breeding program purposes.

The relationship between macro- and micro-nutrients intake and risk of preterm premature rupture of membranes in pregnant women of Isfahan

BACKGROUND

Since preterm premature rupture of membranes (PPROM) is one of the most important complications of pregnancy and its relationship with nutrition status have not been surveyed comprehensively, we decided to study the relationship of maternal received nutrients (36 macro- and micro-nutrients) in three trimesters and PPROM which could be considered as a unique study.

MATERIALS AND METHODS

In this prospective cohort study, data was collected by filling a questionnaire through interviews with 620 pregnant women who had no parameters to affect pregnancy outcome. 48-hr dietary recalls were completed for eligible women at 11th-15th, 26th, 34th-37th weeks of gestation. Physical activity was also assessed using a standard questionnaire. Also pregnant mother's reproductive and demographic characteristic and supplementation are considered.

RESULTS

The mean value of received saturated fatty acids, polyunsaturated fatty acids and energy, in the first trimester (P < 0.001, P = 0.007, and P < 0.001 respectively), the mean values of calcium, sodium intake in the second trimester (P = 0.045, P = 0.006, and P = 0.004 respectively), Vitamins C, A (mg), β-carotene, cartenoids intake in the second trimester (P = 0.03, P = 0.001, P = 0.007, and P = 0.01 respectively), and higher Vitamin C intake during the first trimester (P = 0.02) was significantly greater among subjects with PPROM compared to the others.

CONCLUSIONS

The mean value of mentioned received nutrients in subjects who experienced PPROM later in pregnancy was higher than the others, which is independent of demographic and reproductive characteristic, estimated physical activity, and supplementation. Therefore, these findings could be considered in the nutritional programming for pregnant women to manage the risk of PPROM.

The rise, the fall and the renaissance of vitamin E

This review deals with the expectations of vitamin E ability of preventing or curing, as a potent antioxidant, alleged oxidative stress based ailments including cardiovascular disease, cancer, neurodegenerative diseases, cataracts, macular degeneration and more. The results obtained with clinical intervention studies have highly restricted the range of effectiveness of this vitamin. At the same time, new non-antioxidant mechanisms have been proposed. The new functions of vitamin E have been shown to affect cell signal transduction and gene expression, both in vitro and in vivo. Phosphorylation of vitamin E, which takes place in vivo, results in a molecule provided with functions that are in part stronger and in part different from those of the non-phosphorylate compound. The in vivo documented functions of vitamin E preventing the vitamin E deficiency ataxia (AVED), slowing down the progression of non-alcoholic steato-hepatitis (NASH), decreasing inflammation and potentiating the immune response are apparently based on these new molecular mechanisms. It should be stressed however that vitamin E, when present at higher concentrations in the body, should exert antioxidant properties to the extent that its chromanol ring is unprotected or un-esterified.

Protective effects of rosmarinic acid against radiation-induced damage to the hematopoietic system in mice

Rosmarinic acid (RA) is an ester of caffeic acid and 3, 4-dihydroxyphenyl lactic acid. It is a potent antioxidant that functions by scavenging free radicals. Here, we used a 30-day survival assay to investigate the radioprotective effects of RA. Mice were treated with RA once per day for 10 consecutive days starting at 3 days before gamma irradiation at 7.5 Gy until 7 days post irradiation. Mice treated with 100 and 200 mg/kg body weight (bw) of RA had 30-day survival rates of 89% and 72%, respectively, compared with 32% in the control group, and the differences were statistically significant (P = 0.0008 and 0.0421, respectively). Spleen colony-forming units (CFU-S), the number of nucleated cells in the bone marrow (BMNC), bone marrow DNA content, and hematological parameters of the peripheral blood were measured to investigate the radioprotective effect of RA on the hematopoietic system. The treatment groups that received RA at 50, 100 and 150 mg/kg bw and whole-body exposure to 5.5 Gy of (137)Cs γ- radiation had significantly higher CFU-S, BMNC and DNA content than the irradiation-only group. Assessment of hematological parameters in the peripheral blood showed that the treatment groups receiving RA at doses of 50, 100 and 150 mg/kg bw had higher white blood cell counts, hemoglobin and platelets than the radiation-only group. These results suggested that the administration of RA promoted the recovery of peripheral blood cells in irradiated mice.

Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies

Observational studies evaluating the relation between dietary or circulating level of beta-carotene and risk of total mortality yielded inconsistent results. We conducted a comprehensive search on publications of PubMed and EMBASE up to 31 March 2016. Random effect models were used to combine the results. Potential publication bias was assessed using Egger’s and Begg’s test. Seven studies that evaluated dietary beta-carotene intake in relation to overall mortality, indicated that a higher intake of beta-carotene was related to a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.83, 95%CI: 0.78–0.88) with no evidence of heterogeneity between studies (I² = 1.0%, P = 0.416). A random-effect analysis comprising seven studies showed high beta-carotene level in serum or plasma was associated with a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.69, 95%CI: 0.59–0.80) with low heterogeneity (I² = 37.1%, P = 0.145). No evidence of publication bias was detected by Begg’s and Egger’s regression tests. In conclusion, dietary or circulating beta-carotene was inversely associated with risk of all-cause mortality. More studies should be conducted to clarify the dose-response relationship between beta-carotene and all-cause mortality.

Natural iron chelators: Protective role in A549 cells of flavonoids-rich extracts of Citrus juices in Fe(3+)-induced oxidative stress

Exogenous iron in particulate matter and imbalanced iron homeostasis cause deleterious effects on health. Natural and synthetic iron chelators may be of therapeutic benefit, therefore we evaluated the protective effect of Citrus flavonoids-rich extracts from bergamot and orange juices in iron overloaded human lung epithelial cells. Cytofluorimetric, biochemical and genotoxic analyses were performed in Fe2(SO4)3 exposed A549, pretreated with each extract whose chemical composition was previously detected. Chelating activity was assessed in cells by a calcein ester. Both extracts reduced the generation of reactive oxygen species and membrane lipid peroxidation, improved mitochondrial functionality, and prevented DNA-oxidative damage in iron-exposed cells. Antioxidant effects were attributed to the chelating property, blocking upstream the redox activity of iron. Flavonoid-rich extracts also induced antioxidant catalase. The bergamot and orange juice extracts had a broad-spectrum protective effect. Their use prevents iron oxidative injury and these natural iron chelators could be used as therapeutic agents.

Can Xanthophyll-Membrane Interactions Explain Their Selective Presence in the Retina and Brain?

Epidemiological studies demonstrate that a high dietary intake of carotenoids may offer protection against age-related macular degeneration, cancer and cardiovascular and neurodegenerative diseases. Humans cannot synthesize carotenoids and depend on their dietary intake. Major carotenoids that have been found in human plasma can be divided into two groups, carotenes (nonpolar molecules, such as β-carotene, α-carotene or lycopene) and xanthophylls (polar carotenoids that include an oxygen atom in their structure, such as lutein, zeaxanthin and β-cryptoxanthin). Only two dietary carotenoids, namely lutein and zeaxanthin (macular xanthophylls), are selectively accumulated in the human retina. A third carotenoid, meso-zeaxanthin, is formed directly in the human retina from lutein. Additionally, xanthophylls account for about 70% of total carotenoids in all brain regions. Some specific properties of these polar carotenoids must explain why they, among other available carotenoids, were selected during evolution to protect the retina and brain. It is also likely that the selective uptake and deposition of macular xanthophylls in the retina and brain are enhanced by specific xanthophyll-binding proteins. We hypothesize that the high membrane solubility and preferential transmembrane orientation of macular xanthophylls distinguish them from other dietary carotenoids, enhance their chemical and physical stability in retina and brain membranes and maximize their protective action in these organs. Most importantly, xanthophylls are selectively concentrated in the most vulnerable regions of lipid bilayer membranes enriched in polyunsaturated lipids. This localization is ideal if macular xanthophylls are to act as lipid-soluble antioxidants, which is the most accepted mechanism through which lutein and zeaxanthin protect neural tissue against degenerative diseases.

Carotenoids as a Source of Antioxidants in the Diet

Carotenoids, widely distributed fat-soluble pigments, are responsible for the attractive colorations of several fruits and vegetables commonly present in our daily diet. They are particularly abundant in yellow-orange fruits (carrots, tomatoes, pumpkins, peppers, among others) and, although masked by chlorophylls, in dark green leafy vegetables. Several health benefits have been attributed to carotenoids or to foods rich in these pigments, by means of different mechanisms-of-action, including the role as provitamin A of almost 50 different carotenoids and the antioxidant activity that protects cells and tissues from damage of free radicals and singlet oxygen, providing enhancement of the immune function, protection from sunburn reactions and delaying the onset of certain types of cancer. Common food sources and the efficiency of the absorption of carotenoids, analytical approaches used for measurement of their antioxidant effect and an overview of some epidemiological studies that have been performed to assess the beneficial impact of carotenoids in human health are outlined in this chapter.

Reversible effects of vitamins C and E combination on oxidative stress-induced apoptosis in melamine-treated PC12 cells

Due to its high nitrogen content, melamine was deliberately added to raw milk for increasing the apparent protein content. Previous studies showed that melamine-induced apoptosis and oxidative damage on PC12 cells and rats' hippocampus. Several evidences suggested that vitamin antioxidant reduced oxidative stress and improved organic function. Whether treatments with antioxidant vitamins C or E, otherwise combination of them can attenuate oxidative stress after melamine administration remains to be elucidated. In this study, the reversible effects of vitamin antioxidants was investigated on melamine-induced neurotoxicity in cultured PC12 cells, an in vitro model of neuronal cells. When comparing vitamin C and E, the combination of both statistically increased PC12 cells viability. The results further showed that vitamin complex has effectively reduced the formation of reaction oxygen species, decreased the level of malondialdehyde, and elevated the activities of antioxidative enzymes. Hoechst 33342 staining and flow cytometric analysis of apoptosis showed that vitamin combination treatment effectively prevented PC12 cells from this melamine-induced apoptosis. It revealed the apoptotic nuclear features of the melamine-induced cell death. Additionally, a combination treatment of vitamins effectively inhibited apoptosis via blocking the increased activation of caspase-3. In summary, the vitamin E and C combination treatment could rescue PC12 cells from the injury induced by melamine through the downregulation of oxidative stress and prevention of melamine-induced apoptosis.

Shrimp lipids: a source of cancer chemopreventive compounds

Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp.

Resveratrol protects the brain of obese mice from oxidative damage

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a polyphenolic phytoalexin that exerts cardioprotective, neuroprotective, and antioxidant effects. Recently it has been shown that obesity is associated with an increase in cerebral oxidative stress levels, which may enhance neurodegeneration. The present study evaluates the neuroprotective action of resveratrol in brain of obese (ob/ob) mice. Resveratrol was administered orally at the dose of 25 mg kg⁻¹ body weight daily for three weeks to lean and obese mice. Resveratrol had no effect on body weight or blood glucose levels in obese mice. Lipid peroxides were significantly increased in brain of obese mice. The enzymatic antioxidants superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and nonenzymatic antioxidants tocopherol, ascorbic acid, and glutathione were decreased in obese mice brain. Administration of resveratrol decreased lipid peroxide levels and upregulated the antioxidant activities in obese mice brain. Our findings indicate a neuroprotective effect of resveratrol by preventing oxidative damage in brain tissue of obese mice.

Extension of lifespan and protection against oxidative stress by an antioxidant herb mixture complex (KPG-7) in Caenorhabditis elegans

Excessive generation of reactive oxygen species within cells results in oxidative stress. Furthermore, accumulation of reactive oxygen species has been shown to reduce cell longevity. Many dietary supplements are believed to have anti-aging effects. The herb mixture KPG-7 contains several components with antioxidant activity. We aim to clarify the mechanisms responsible for the antioxidant activity of KPG-7 and to establish whether KPG-7 has an anti-aging effect. We examined whether dietary supplementation with KPG-7 could provide protection against oxidative stress, extend lifespan, and delay aging in Caenorhabditis elegans (C. elegans). We found that KPG-7 extended lifespan and delayed aging in adult C. elegans. The expression of oxidation resistance 1 protein was induced by juglone and this effect was significantly suppressed in KPG-7-treated. In addition, the amount of oxidized protein was significantly lower in KPG-7-treated worms than untreated worms. Furthermore, locomotive activity was increased in C. elegans at 3 days of age following the treatment with KPG-7. On the other hand, the level of cellular ATP was lower at 3 days of age in worms treated with KPG-7 than in untreated worms. KPG-7 increases lifespan and delays aging in C. elegans, well corresponding to its activity to protect against oxidative stress.

Protection of astaxanthin in astaxanthin nanodispersions using additional antioxidants

The protective effects of α-tocopherol and ascorbic acid on astaxanthin in astaxanthin nanodispersions produced via a solvent-diffusion technique and stabilized by a three-component stabilizer system, were studied either individually or in combination by using response surface methodology. Generally, both α-tocopherol and ascorbic acid could retard the astaxanthin degradation in astaxanthin nanodispersions. The results showed that the using α-tocopherol and ascorbic acid can be more efficient in increasing the chemical stability of nanodispersions in comparison to using them individually. Using a response surface methodology (RSM) response optimizer, it was seen that addition of ascorbic acid (ascorbic acid/astaxanthin w/w) and α-tocopherol (α-tocopherol/astaxanthin w/w) in proportions of 0.4 and 0.6, respectively, would give the maximum chemical stability to the studied astaxanthin nanodispersions.

Relevance of the Mention of Antioxidant Properties in Yogurt Labels: In Vitro Evaluation and Chromatographic Analysis

The purpose of the inclusion of fruit (natural additives) in yogurt aims to increase its antioxidant activity and functionality. Herein, a comparative study of the antioxidant potential of yogurts with pieces of various fruits was performed, including yogurts with mention of antioxidant properties in the label. Free radicals scavenging activity, reducing power and inhibition of lipid peroxidation were evaluated by in vitro assays, as were the contents in antioxidants such as phenolics, flavonoids, sugars and tocopherols. After analyzing thirteen yogurts containing fruit pieces and a natural one (control), the most interesting were yogurts with pieces of berries (for phenolics, flavonoids and 2,2-dipheny-1-picrylhydrazyl (DPPH) scavenging activity), pineapple (for reducing power), blackberry (for β-carotene bleaching inhibition), blackberry “antioxidant” (for tocopherols) and cherry (for sugars). The mention of “antioxidant” in the label was relevant for tocopherols, sugars, DPPH scavenging activity and reducing power. No synergisms were observed in yogurts prepared with pieces of different fruits. Nevertheless, the addition of fruit pieces to yogurt was favorable for antioxidant content, increasing the protection of the consumer against diseases related to oxidative stress.

Does pharmacodynamic interaction of nonenzymatic antioxidants modify response to antioxidant therapy in the process of atherosclerosis?

A discrepancy exists between clinical trials and epidemiological studies on the effect of antioxidants on cardiovascular disease. This discrepancy could be attributed to the lack of knowledge on the effect of interaction of exogenous antioxidant supplementation with one another or on the effect of interaction of exogenously administered antioxidant vitamins with endogenous ones. This study attempts a systematic review of available data on possible synergistic, additive, or antagonistic action of nonenzymatic antioxidants in atherosclerosis. Electronic databases were searched with the available search terms up to and including February 2010. Eligibility criteria were full publications, clinical trials, epidemiological studies, or in vitro or in vivo studies that investigated the effect of pharmacodynamic interaction of 2 or more antioxidants in the process of atherosclerosis and /or the mechanism of interaction. Eligible clinical trials should have at least 4 arms, 1 arm for the study of each antioxidant alone, 1 for the effect of both antioxidants, and 1 arm for the effect of placebo. In vitro data as well as the limited number of identified randomized clinical trials suggested that coadministration of antioxidants results in synergistic or additive interaction in the process of atherosclerosis. No study demonstrated antagonistic interaction between antioxidants.

Determination of the antioxidative capacity of the skin in vivo using resonance Raman and electron paramagnetic resonance spectroscopy

BACKGROUND

Non-invasive measurements are of major interest for investigating the effects of stress, nutrition, diseases or pharmaceuticals on the antioxidative capacity of the human skin. However, only a few non-invasive methods are available.

MATERIAL AND METHODS

The resonance Raman spectroscopy is well established to monitor carotenoids in the skin, but correlations with other antioxidants have not yet been described. Electron paramagnetic resonance spectroscopy used for measurements of free radicals has already been used elsewhere to investigate the reduction of applied long-living nitroxide radicals, caused by skin antioxidants and UV irradiation, but only a single or up to four volunteers were included in these studies. Therefore, in this study, the two methods were applied in parallel on 17 volunteers, and the rate constant of the nitroxide decrease was correlated with the cutaneous carotenoid concentration.

RESULTS AND DISCUSSION

A correlation with R = 0.65 was found, supporting the thesis that different antioxidants protect each other and build an antioxidative network in the skin. The results also give first indications that the carotenoids serve as marker substances for the antioxidative capacity, if the nutrition is well balanced.

beta-Carotene exhibits antioxidant and anti-apoptotic properties to prevent ethanol-induced cytotoxicity in isolated rat hepatocytes

The study was designed to evaluate the effects of 1 microM beta-carotene on antioxidant status in ethanol-treated rat hepatocytes and investigate possible anti-apoptotic mechanisms of beta-carotene in protecting ethanol-induced cytotoxicity. The isolated rat hepatocytes were incubated for 48 h in a medium with or without alcohol (100 mM) and mu-carotene (1 microM) using the following groups: the control (C), beta-carotene (CB), ethanol (E), and ethanol + beta-carotene (EB) groups. The cell viability, antioxidative status, cytochrome P450 2E1 (CYP2E1) and caspase expressions in hepatocytes were measured. The E group demonstrated lower cell viability, glutathione (GSH) levels, and lipid peroxide accumulation in rat hepatocytes; meanwhile, CYP2E1, caspase-3, and caspase-9 expressions increased. In contrast, cell viability, GSH levels, and glutathione reductase (GRD) activity significantly increased while lipid peroxides and expressions of CYP2E1, casapse-3, and caspase-9 decreased in the EB group. The results suggest that ethanol treatment decreases cell viability in rat hepatocytes via induced oxidative stress. 1 muM beta-carotene decreased oxidative stress and prevented ethanol-induced cell death by inhibiting caspase-9 and caspase-3 expression.

Potential therapeutic effects of vitamin e and C on placental oxidative stress induced by nicotine: an in vitro evidence

There have been a few studies that examined the oxidative stress effects of nicotine during pregnancy and lactation. The adverse effect of prenatal smoking exposure on human fetal development and growth has been a major public health issue. Active or passive smoking during pregnancy can result in a wide variety of adverse outcomes, including intrauterine growth retardation (IUGR), prematurity, stillbirth, and the sudden infant death syndrome. Smoking in pregnancy has also been associated with an increased risk of attention deficit and learning problems in childhood. Some studies argued that as a principal component of tobacco smoke, nicotine alone is responsible for the majority of negative reproductive outcomes. Nicotine and its major metabolite cotinine can cross the placental barrier. The level of nicotine in fetal tissues was found to be equal to or greater than the plasma nicotine level in the mothers. The oxidative stress induce by nicotine has been increasingly postulated as a major contributor to endothelial dysfunction. A large body of research has investigated the potential role of antioxidant nutrients in the prevention of endothelial dysfunction in women. Therefore, the present study was undertaken to assess the potential benefit of antioxidant supplementation on markers of placental oxidative stress in an in vitro model of endothelial dysfunction induced by nicotine, since it was previously found that nicotine is able to trigger the placental secretion of stress molecules. In this regard, we evaluated the effects of vitamin C, vitamin E and N-acetylcysteine (NAC), alone or in combination, in placental villi culture after exposure to nicotine. The effect of antioxidant nutrients on trophoblast cells proliferation and vitality was also evaluated. The results obtained suggest that in a patho-physiological condition, such as endothelial dysfunction induced by nicotine, the deleterious effect of reactive oxygen species may be counteracted by an antioxidant therapy, and there is the need to investigate the optimum dosing and timing of antioxidants administration, since an inappropriate antioxidant treatment in pregnant women may have deleterious consequences, reducing placental cells proliferation until to cell death.

Proteasomal degradation of beta-carotene metabolite--modified proteins

Free radical attack on beta-carotene results in the formation of high amounts of carotene breakdown products (CBPs) having biological activities. As several of the CBPs are reactive aldehydes, it has to be considered that these compounds are able to modify proteins. Therefore, the aim of the study was to investigate whether CBP-modification of proteins is leading to damaged proteins recognized and degraded by the proteasomal system. We used the model proteins tau and ferritin to test whether CBPs will modify them and whether such modifications lead to enhanced proteasomal degradation. To modify proteins, we used crude CBPs as a mixture obtained after hypochloric acid derived BC degradation, as well as several single compounds, as apo8'-carotenal, retinal, or beta-ionone. The majority of the CBPs found in our reaction mixture are well known metabolites as described earlier after BC degradation using different oxidants. CBPs are able to modify proteins, and in in vitro studies, we were able to demonstrate that the 20S proteasome is able to recognize and degrade CBP-modified proteins preferentially. In testing the proteolytic response of HT22 cells toward CBPs, we could demonstrate an enhanced protein turnover, which is sensitive to lactacystin. Interestingly, the proteasomal activity is resistant to treatment with CBP. On the other hand, we were able to demonstrate that supraphysiological levels of CBPs might lead to the formation of protein-CBP-adducts that are able to inhibit the proteasome. Therefore, the removal of CBP-modified proteins seems to be catalyzed by the proteasomal system and is effective, if the formation of CBPs is not overwhelming and leading to protein aggregates.