Functional food science and defence against reactive oxidative species

Reflections on the theory of "silver bullet" octreotide tracers: implications for ligand-receptor interactions in the age of peptides, heterodimers, receptor mosaics, truncated receptors, and multifractal analysis

The classical attitude of Nuclear Medicine practitioners on matters of peptide-receptor interactions has maintained an intrinsic monogamic character since many years. New advances in the field of biochemistry and even in clinical Nuclear Medicine have challenged this type of thinking, which prompted me to work on this review. The central issue of this paper will be the use of somatostatin analogs, i.e., octreotide, in clinical imaging procedures as well as in relation to neuroendocirne tumors. Newly described characteristics of G-protein coupled receptors such as the formation of receptor mosaics will be discussed. A small section will enumerate the regulatory processes found in the cell membrane. Possible new interpretations, other than tumor detection, based on imaging procedures with somatostatin analogs will be presented. The readers will be taken to situations such as inflammation, nociception, mechanosensing, chemosensing, fibrosis, taste, and vascularity where somatostatin is involved. Thyroid-associated orbitopathy will be used as a model for the development of multi-agent therapeutics. The final graphical summary depicts the multifactorial properties of ligand binding.

Total polyphenolic (flavonoids) content and antioxidant capacity of different Ziziphora clinopodioides Lam. extracts

OBJECTIVE

This paper investigates the total polyphenolic and flavonoid content as well as the antioxidant activity of Ziziphora clinopodioides Lam. extracts of different polarity.

MATERIALS AND METHODS

The total polyphenolic content was analysed using the Folin-Ciocalteu method. Total flavonoid content analysis was performed using the colorimetric method.

RESULTS

The total polyphenolic content of Z. clinopodioides is concentrated in parts of ethyl acetate (19.27%), chloroform (4.99%) and n-butanol extracts (3.94%) containing a small amount of the total polyphenolic content. The petroleum ether (0.23%) and ethanol extracts (1.64%) contain almost no polyphenolic content. The total flavonoid content of Z. clinopodioides is concentrated in parts of ethyl acetate (65.61%), chloroform (14.36%) and n-butanol extracts (10.76%) containing a small amount of the total polyphenolic content. The Z. clinopodioides Lam. ethyl acetate extract exhibits a good antioxidant activity.

CONCLUSION

Ethyl acetate extracts contain a large number of polyphenolic compounds (19.27%) and flavonoids (65.61%) owing to good antioxidant capacity.

Antioxidants in foods: state of the science important to the food industry

Antioxidant foods and ingredients are an important component of the food industry. In the past, antioxidants were used primarily to control oxidation and retard spoilage, but today many are used because of putative health benefits. However, the traditional message that oxidative stress, which involves the production of reactive oxygen species (ROS), is the basis for chronic diseases and aging is being reexamined. Accumulating evidence suggests that ROS exert essential metabolic functions and that removal of too many ROS can upset cell signaling pathways and actually increase the risk of chronic disease. It is imperative that the food industry be aware of progress in this field to present the science relative to foods in a forthright and clear manner. This may mean reexamining the health implications of adding large amounts of antioxidants to foods.

Dose-response relationship for α-tocopherol prevention of ultraviolet radiation induced cataract in rat

The purpose of this study is to establish the dose response relationship for α-tocopherol protection of ultraviolet radiation (UVR) induced cataract in the rat. Four groups of 20 six-week-old albino Sprague Dawley rats received 5, 25, 50, and 100 IU/day α-tocopherol, whilst another group of 20 rats without any α-tocopherol feeding was the control group. After 4 weeks of feeding, each rat was unilaterally exposed to 8 kJ/m(2) UVR-300 nm for 15 min. At 1 week after exposure, the rats were sacrificed and lens light scattering was measured quantitatively. Lens total reduced (GSH) and oxidized (GSSG) glutathione; glutathione reductase (GR) and peroxidase (GPx) were determined spectrophotometrically. The UVR-exposed lenses in the α-tocopherol fed groups developed superficial cataract, whereas lenses in the control group developed cortical and equatorial opacities. Light scattering in lenses from the α-tocopherol-supplemented rats was lower than in lenses from the control group. The difference of light scattering between the exposed and contralateral non-exposed lens decreased with increasing doses of α-tocopherol to an asymptote level. UVR-exposure caused a significant depletion of lens GSH in rats without or at low α-tocopherol supplementation. The depletion of GSH became less with higher α-tocopherol supplementation. There was no detectable difference in lens GSSG, GR or GPx at any level of α-tocopherol supplementation. Orally administered α-tocopherol dose dependently protects against UVR-induced cataract. The protection is associated with an α-tocopherol dose-dependent GSH depletion secondary to UVR exposure. UVR-induced light scattering only occurs if the GSH depletion exceeds a threshold.

Multifunctional cytotoxic agents from Anacardium occidentale

The effects of anacardic acids and cardols isolated from the cashew nut and apple Anacardium occidentale (Anacardiaceae) on murine B16-F10 melanoma cells were tested. Although anacardic acids and cardols were found to inhibit tyrosinase, a key enzyme in melanin synthesis, melanogenesis in melanocytes was not suppressed in cultured cells but rather enhanced. Both anacardic acids and cardols exhibited moderate cytotoxicity.

Inonotus obliquus protects against oxidative stress-induced apoptosis and premature senescence

In this study, we investigated the cytoprotective effects of Inonotus obliquus against oxidative stress-induced apoptosis and premature senescence. Pretreatment with I. obliquus scavenged intracellular ROS and prevented lipid peroxidation in hydrogen peroxide-treated human fibroblasts. As a result, I. obliquus exerted protective effects against hydrogen peroxide-induced apoptosis and premature senescence in human fibroblasts. In addition, I. obliquus suppressed UV-induced morphologic skin changes, such as skin thickening and wrinkle formation, in hairless mice in vivo and increased collagen synthesis through inhibition of MMP-1 and MMP-9 activities in hydrogen peroxide-treated human fibroblasts. Taken together, these results demonstrate that I. obliquus can prevent the aging process by attenuating oxidative stress in a model of stress-induced premature senescence.

Effects of high hydrostatic pressure (HHP) on bioaccessibility, as well as antioxidant activity, mineral and starch contents in Granny Smith apple

The aim of this work was to study the effect of high hydrostatic pressure on the bioaccessibility of specific nutrients (antioxidant, minerals and starch) in apple and to establish processing conditions that maximise the health benefits. The apple was pressurised at 500MPa during 2, 4, 8 and 10min. The antioxidant activity, mineral and starch content and bioaccessibility of apple samples were significantly affected by the processing and digestion conditions. Therefore, these results indicated that in vitro digestion has a noticeable effect on the antioxidant concentration, IC50, with much lower values (a smaller IC50 value corresponds to a higher antioxidant activity) of apple samples compared with those untreated and non-digestion. Apple has the highest calcium content (30.33±1.94mg/100g), iron (14.46±3.49mg/100g) and zinc (6.22±0.91mg/100g). High hydrostatic pressure increased the mineral contents availability by 2.11-303.00% for calcium, 4.63-10.93% for iron and 8.68-28.93% for zinc. The dialysability and solubility of calcium, iron and zinc with respect to the values for the untreated sample were reduced by this high pressure technique. Consumption of apple under high hydrostatic pressure may supply substantial antioxidants, mineral and starch, which may provide health promoting and disease preventing effects.

Effect of cooking on total vitamin C contents and antioxidant activity of sweet chestnuts (Castanea sativa Mill.)

In this work the total vitamin C contents (ascorbic acid+dehydroascorbic acid) and antioxidant activity of raw and cooked chestnuts was evaluated. The vitamin C contents of raw chestnuts varied significantly between the different cultivars (cv) studied and it varied from 400mg/kg dry weight (cv Lada) to 693mg/kg dry weight (cv Martaínha). The different cultivars behave differently during the cooking process concerning the loss of vitamin C. A significant decrease in the vitamin C content of the chestnuts was observed, 25-54% for the boiling process and 2-77% for the roasting process. Boiled and roasted chestnuts can be good sources of vitamin C since it may represent 22.4%, 16.2%, 26.8% and 19.4%, respectively, of the recommended dietary intake for an adult man and woman. The cooking process significantly changed the antioxidant activity of the chestnuts. A difference was observed between the cultivars during the cooking processes, concerning the antioxidant activity. For the raw chestnuts the variation in vitamin C content of the chestnuts explains 99% of the antioxidant activity variation but for the roasted and boiled chestnuts this percentage significantly decreases to 51% and 88%, respectively. Although a high antioxidant activity is still present in the cooked chestnuts, the cause for this antioxidant activity is less dependent on the vitamin C content of the chestnuts, probably due to the conversion of ascorbic acid to dehydroascorbic acid. The increase in gallic acid during the cooking process, presumably transferred from the peels to the fruit, also contributes to the high antioxidant activity observed for the cooked chestnuts.

Vitamin C: Overview and Update

Vitamin C functions in enzyme activation, oxidative stress reduction, and immune function. There is considerable evidence that vitamin C protects against respiratory tract infections and reduces risk for cardiovascular disease and some cancers. Current trials are examining the efficacy of intravenous vitamin C as cancer therapy. Many experts believe that the recommended intakes for vitamin C (45 to 90 mg daily) are several orders of magnitude too low to support optimal vitamin C functionality. Also, there is a misperception that vitamin C deficiency disease (scurvy) is largely historical and rarely observed in developed nations. Physical symptoms of scurvy include swelling of the lower extremities, bleeding gums, fatigue, and hemorrhaging, as well as psychological problems, including depression, hysteria, and social introversion. The long-term safety of vitamin C supplementation seems evident as large investigations have noted reduced risk of mortality in vitamin C supplementing populations and in those with elevated plasma vitamin C concentrations.

Anticancer drugs from marine flora: an overview

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

A review of ascorbic acid potentialities against oxidative stress induced in plants

Ascorbic acid (AA) currently holds a significant position in plant physiology, mainly due to its possession of antioxidant and cellular reductant etc.properties and its diverse roles in plant growth and development and the regulation of a broad spectrum of plant cellular mechanisms against environmental stresses. Some researchers suggest that endogenous AA has been implicated in the promotion of plant growth and development by involvement in a complex and enigmatic array of phytohormone-regulated signalling networks that ties together different environmental stresses. As it is evident from the present review, recent progress on AA potentiality in the tolerance of plants to environmental stresses has been impressive. Indeed, AA plays an important role in resistance to oxidative stresses such as heavy metal, saline, ultra-violet etc. Rapidly increasing evidence indicates that AA is centrally involved in several physiological processes but there has been much disagreement regarding the mechanism(s) by which AA reduces the damaging effects of such stresses in plants. Perhaps the role of AA in mediating tolerance to abiotic stress (e.g. UV, salinity and temperature, etc.) will lead to a greater research focus in the near future. In addition, AA might provide a suitably attractive target for the enhancement of crop production.

A beverage containing fermented black soybean ameliorates ferric nitrilotriacetate-induced renal oxidative damage in rats

It is beneficial to seek scientific basis for the effects of functional foods. Natural pigments derived from plants are widely known as possible antioxidants. Black soybean contains a larger amount of anthocyanins than regular soybean. Here we studied the antioxidative effect of a beverage obtained via citric acid fermentation of black soybean (BBS), using a rat model of renal oxidative injury induced by a renal carcinogen, ferric nitrilotriacetate. BBS (10 ml/kg) was orally administered 30 min before ferric nitrilotriacetate treatment. Renal lipid peroxidation was significantly suppressed in the BBS-pretreated animals concomitant with decrease in 4-hydroxy-2-nonenal-modified proteins and 8-hydroxy-2'-deoxyguanosine. Maintenance of renal activities of antioxidative enzymes including catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, glucose-6-phosphate dehydrogenase and quinone reductase was significantly better in the BBS-pretreated rats. Elevation of serum creatinine and urea nitrogen was significantly suppressed in the BBS-pretreated rats. These data suggest that dietary intake of BBS is useful for the prevention of renal tubular oxidative damage mediate by iron, and warrant further investigation.

Phenolic compounds and vitamin antioxidants of caper (Capparis spinosa)

Capparis spinosa shows strong resistance to the adverse Mediterranean conditions and it has nutritional and medicinal value. The aim of this study was to evaluate the contents of total phenolic compounds, rutin, tocopherols, carotenoids and vitamin C in leaves and flower buds of C. spinosa from different locations in Tunisia. Results showed the richness of caper with these compounds, especially phenolic compounds. Interestingly, it was also found the presence of both α- and γ-tocopherol in buds. Moreover, C. spinosa contained an appreciable level of vitamin C. The significant amounts of these antioxidants confirm the nutritional and medicinal value of caper.

Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties

BACKGROUND

Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) and to understand whether fractionation could improve its content in bioactive peptides.

RESULTS

The starting fish protein hydrolysate exhibited a balanced amino acid composition, a reproducible molecular weight (MW) profile, and a low sodium chloride content, allowing the study of its biological activity. Successive fractionation on UF and NF membranes allowed concentration of peptides of selected sizes, without, however, carrying out sharp separations, some MW classes being found in several fractions. Peptides containing Pro, Hyp, Asp and Glu were concentrated in the UF and NF retentates compared to the unfractionated hydrolysate and UF permeate, respectively. Gastrin/cholecystokinin-like peptides were present in the starting FPH, UF and NF fractions, but fractionation did not increase their concentration. In contrast, quantification of calcitonin gene-related peptide (CGRP)-like peptides demonstrated an increase in CGRP-like activities in the UF permeate, relative to the starting FPH. The starting hydrolysate also showed a potent antioxidant and radical scavenging activity, and a moderate angiotensin-converting enzyme (ACE)-1 inhibitory activity, which were not increased by UF and NF fractionation.

CONCLUSION

Fractionation of an FPH using membrane separation, with a molecular weight cut-off adapted to the peptide composition, may provide an effective means to concentrate CGRP-like peptides and peptides enriched in selected amino acids. The peptide size distribution observed after UF and NF fractionation demonstrates that it is misleading to characterize the fractions obtained by membrane filtration according to the MW cut-off of the membrane only, as is currently done in the literature.

Effect of Lactobacillus fermentum and Enterococcus faecium strains on internal milieu, antioxidant status and body weight of broiler chickens

The aim of the present study was to evaluate the functional efficiency of two probiotic strains Lactobacillus fermentum CCM 7158 and Enterococcus faecium M 74 given to the drinking water on internal milieu, antioxidant status and body weight of broiler chickens. The experiment was conducted on hybrid Hybro (n = 180). The feeding period lasted 42 days. Experimental chickens of E1 group received a probiotic preparation in drinking water with concentration of 1 × 10(9) colony forming units (CFU) of L. fermentum CCM 7158 in 1 g of nutrient medium and experimental chickens of E2 group concentration of 2 × 10(9) CFU of E. faecium M 74 in 1 g of nutrient medium. The control group of animals received water without any additives. Triglycerides content in serum mainly with L. fermentum strain against the control group was decreased. Calcium content in both experimental groups and significantly in E. faecium group was increased. Antioxidant status in both probiotic groups was significantly increased. The content of bilirubin in group with E. faecium M 74 was significantly increased. In conclusion, addition of a microbial feed additive (L. fermentum and E. faecium) increased serum calcium and iron level, decreased triglycerides content in blood and slightly increased body weight of broiler chickens.

Antioxidant properties of Galium verum L. (Rubiaceae) extracts

The antioxidant properties of methanol extracts of Lady’s Bedstraw (Galium verum L., Rubiaceae) herb from two different localities in Serbia were evaluated. Antioxidant activity was assessed in four different model systems. Free radical scavenging capacity (RSC) was examined by measuring the scavenging activity of extracts on 2,2-diphenyl-1-pycrylhydrazil (DPPH) and hydroxyl radical (OH), as well as on hydrogen peroxide. In addition, the protective effects of lipid peroxidation (LP) in corn oil were evaluated by the TBA-assay using the Fe2+/ascorbate system of induction. The amount of dried extract, the content of total phenolics, flavonoids and chlorophylls was also determined. Extracts from both locations expressed very strong scavenger activity, reducing the DPPH⊙ (IC50=3.10 µg/mland 8.04 µg/ml) and OH radical formation (IC50=0.05 µg/ml and 0.54 µg/ml) and neutralising H2O2 (IC50=4.98 µg/ml and 3.80 µg/ml), in a dose dependant manner. Also, examined extracts showed notable inhibition of LP (IC50=11.69 µg/ml and 19.47 µg/ml). The observed differences in antioxidant activity could be partially explained by the levels of phenolics (2.44–4.65 mg and 4.57–5.16 mg gallic acid equivalents/g dry extract), flavonoids (6.38–10.70 µg and 15.56–17.96 µg quercetin equivalents/g dry extract) and chlorophylls in the investigated Lady’s Bedstraw extracts.

Food preservatives sodium benzoate and propionic acid and colorant curcumin suppress Th1-type immune response in vitro

Food preservatives sodium benzoate and propionic acid and colorant curcumin are demonstrated to suppress in a dose-dependent manner Th1-type immune response in human peripheral blood mononuclear cells (PBMC) in vitro. Results show an anti-inflammatory property of compounds which however could shift the Th1-Th2-type immune balance towards Th2-type immunity.

Effects of Caffeoylquinic Acid Derivatives and C-Flavonoid from Lychnophora ericoides on in vitro Inflammatory Mediator Production

In this study we aimed at evaluating the effect of the major polar constituents of the medicinal plant Lychnophora ericoides on the production of inflammatory mediators produced by LPS-stimulated U-937 cells. The 6,8-di- C-β-glucosylapigenin (vicenin-2) presented no effect on tumor necrosis factor (TNF)-α production, but inhibited, in a dose-dependent manner, the production of prostaglandin (PG) E2 without altering the expression of cyclooxygenase (COX) -2 protein. 3,5-Dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid, at lower concentrations, had small but significant effects on reducing PGE2 levels; at higher doses these compounds stimulated PGE2 and also TNF-α production by the cells. All the caffeoylquinic acid derivatives, in a dose-dependent fashion, were able to inhibit monocyte chemoattractant protein-3 synthesis/release, with 4,5-DCQ being the most potent at the highest tested concentration. These results add important information on the effects of plant natural polyphenols, namely vicenin-2 and caffeoylquinic acid derivatives, on the production of inflammatory mediators by cultured cells.

Comparative study of eight well-known polyphenolic antioxidants

Eight antioxidants from five different polyphenolic classes (cinnamic acids, benzoic acids, flavonoids, proanthocyanidins and stilbenes), and the water-soluble vitamin E derivative trolox were examined for their antioxidant activity in-vitro. In addition, the compounds were tested for their cytotoxicity on growing fibroblasts and their inhibition of the classical pathway of the complement system. Procyanidin C1 was shown to be a good scavenger of both DPPH* and HO*, and a strong inhibitor of lipid peroxidation and the classical pathway of the complement system. Consequently, procyanidin C1 was classified as the most promising antioxidant in-vitro of all compounds tested. In contrast, genistein exhibited a very low antioxidant activity in both the lipid peroxidation and the DPPH* scavenging assay, a high cytotoxicity and a low complement-inhibiting activity.

Protective effect of apricot (Prunus armeniaca L.) on hepatic steatosis and damage induced by carbon tetrachloride in Wistar rats

The present study was planned to investigate the protective effect of 10 % and 20 % apricot-containing feed on carbon tetrachloride (CCl4)-induced hepatic steatosis and damage. Adult male Wistar rats (n 42) were divided into six groups of seven each, as follows: control group; CCl4 group; CCl4+10 % apricot group; CCl4+20 % apricot group; 10 % apricot group; 20 % apricot group. All apricot groups were fed with 10 % or 20 % apricot-containing feed for 5 months. CCl4 injections were applied to the CCl4 groups at the dose of 1 mg/kg for 3 d at the end of 5 months. In the CCl4 group, vacuolated hepatocytes and hepatic necrosis were seen, especially in the centrilobular area. Hepatocytes showed an oedematous cytoplasmic matrix, large lipid globules and degenerated organelles. The area of liver injury was found significantly decreased with apricot feeding. Malondialdehyde and total glutathione levels and catalase, superoxide dismutase and glutathione peroxidase activities were significantly changed in the CCl4 group and indicated increased oxidative stress. Apricot feeding decreased this oxidative stress and ameliorated histological damage. We concluded that apricot feeding had beneficial effects on CCl4-induced liver steatosis and damage probably due to its antioxidant nutrient (beta-carotene and vitamin) contents and high radical-scavenging capacity. Dietary intake of apricot can reduce the risk of liver steatosis and damage caused by free radicals.

Diet supplementation with acai (Euterpe oleracea Mart.) pulp improves biomarkers of oxidative stress and the serum lipid profile in rats

OBJECTIVE

We investigated the antioxidant potential and hypocholesterolemic effects of acai (Euterpe oleracea Mart.) pulp ingestion in rats fed a standard or hypercholesterolemic diet.

METHODS

Female Fischer rats were fed a standard AIN-93 M diet (control) or a hypercholesterolemic diet that contained 25% soy oil and 1% cholesterol. The test diet was supplemented with 2% acai pulp (dry wt/wt) for control (group CA) and hypercholesterolemic rats (group HA) for 6 wk. At the end of the experimental period, rats were sacrificed and the blood and livers were collected. To evaluate the effect of acai consumption, levels of protein carbonyl and sulfhydryl groups, superoxide dismutase and paraoxonase activities, and lipid profiles of the sera were measured.

RESULTS

Animals that were fed the hypercholesterolemic diet presented increased levels of total and non-high-density lipoprotein cholesterol and decreased levels of high-density lipoprotein cholesterol. Supplementing the diet of this group with acai caused a hypocholesterolemic effect by reducing total and non-high-density lipoprotein cholesterol. Serum levels of carbonyl proteins and total, free, and protein sulfhydryl groups were reduced by acai ingestion in animals receiving the standard or hypercholesterolemic diet. Acai supplementation induced a significant reduction in superoxide dismutase activity only in the hypercholesterolemic rats, indicating an association between diet and acai treatment. Also, acai supplementation increased paraoxonase activity in the CA and HA groups.

CONCLUSION

These results suggest that the consumption of acai improves antioxidant status and has a hypocholesterolemic effect in an animal model of dietary-induced hypercholesterolemia.

Plant polyphenols in cancer and heart disease: implications as nutritional antioxidants

Certain dietary antioxidants such as vitamin E and vitamin C are important for maintaining optimum health. There is now much interest in polyphenolic products of the plant phenylpropanoid pathway as they have considerable antioxidant activity in vitro and are ubiquitous in our diet. Rich sources include tea, wine, fruits and vegetables although levels are affected by species, light, degree of ripeness, processing and storage. This confounds the formulation of databases for the estimation of dietary intakes. Most attention to date has focused on the flavonoids, a generic term which includes chalcones, flavones, flavanones, flavanols and anthocyanins. There is little convincing epidemiological evidence that intakes of polyphenols are inversely related to the incidence of cancer whereas a number of studies suggest that high intakes of flavonoids may be protective against CHD. In contrast, numerous cell culture and animal models indicate potent anticarcinogenic activity by certain polyphenols mediated through a range of mechanisms including antioxidant activity, enzyme modulation, gene expression, apoptosis, upregulation of gap junction communication and P-glycoprotein activation. Possible protective effects against heart disease may be due to the ability of some polyphenols to prevent the oxidation of LDL to an atherogenic form although anti-platelet aggregation activity and vasodilatory properties are also reported. However, some polyphenols are toxic in mammalian cells. Thus, until more is known about their bioavailability, metabolism and intracellular location, increasing intakes of polyphenols by supplements or food fortification may be unwise.

High dietary antioxidant intakes are associated with decreased chromosome translocation frequency in airline pilots

BACKGROUND

Dietary antioxidants may protect against DNA damage induced by endogenous and exogenous sources, including ionizing radiation (IR), but data from IR-exposed human populations are limited.

OBJECTIVE

The objective was to examine the association between the frequency of chromosome translocations, as a biomarker of cumulative DNA damage, and intakes of vitamins C and E and carotenoids in 82 male airline pilots.

DESIGN

Dietary intakes were estimated by using a self-administered semiquantitative food-frequency questionnaire. Translocations were scored by using fluorescence in situ hybridization with whole chromosome paints. Negative binomial regression was used to estimate rate ratios and 95% CIs, adjusted for potential confounders.

RESULTS

Significant and inverse associations were observed between translocation frequency and intakes of vitamin C, beta-carotene, beta-cryptoxanthin, and lutein-zeaxanthin from food (P < 0.05). Translocation frequency was not associated with the intake of vitamin E, alpha-carotene, or lycopene from food; total vitamin C or E from food and supplements; or vitamin C or E or multivitamin supplements. The adjusted rate ratios (95% CI) for > or =median compared with or =median compared with

CONCLUSION

High combined intakes of vitamins C and E, beta-carotene, beta-cryptoxanthin, and lutein-zeaxanthin from food, or a diet high in their food sources, may protect against cumulative DNA damage in IR-exposed persons.

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Key Words Collapse

MESH Headings

• Administration, Oral
• Aircraft
• Antioxidants/administration & dosage
• Antioxidants/pharmacology
• Ascorbic Acid/pharmacology
• Carotenoids/administration & dosage
• Carotenoids/pharmacology
• Chromosomes, Human/drug effects
• Chromosomes, Human/genetics
• Dietary Supplements
• Fruit
• Humans
• Interviews as Topic
• Male
• Occupations
• Surveys and Questionnaires
• Translocation, Genetic/drug effects
• Vegetables
• Vitamin E/pharmacology
• beta Carotene/administration & dosage

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Grants

• Y1CP802904 NCI NIH HHS
• Intramural NIH HHS

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Affiliation(s)

Lee C Yong National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, OH 45226, USA.
Martin R Petersen
Alice J Sigurdson
Laura A Sampson
Elizabeth M Ward

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Changes in antioxidant compounds during the shelf life of commercial tomato juices in different packaging materials

Tomatoes provide an optimal mix of dietary antioxidants that may be responsible for the reported health benefits of tomato consumption. However, technological processing, packaging materials, and storage conditions have an impact on the nutritional quality of tomato products by affecting the stability of antioxidant nutrients to different extents. In this study, we evaluated the stability of the antioxidant compounds (lycopene, ascorbic acid, total phenols, and total flavonoids) present in commercially available tomato juices during storage extended for 12 months at three different temperatures (8, 22, and 37 degrees C). To further characterize the impact of storage conditions, two commonly used packaging materials (Tetra pack and glass bottles) were used to determine whether packaging materials affect antioxidant stability. Overall, the total lycopene, total phenolic compounds, and total flavonoids remained almost stable during storage for 12 months, regardless of the packaging material used, indicating that tomato juices maintain their nutritional value in terms of antioxidant composition during their shelf life. However, ascorbic acid was the most labile antioxidant and was markedly affected by storage conditions. The hydrophilic total antioxidant activity (TAA) paralleled the losses in ascorbic acid content, whereas the lipophilic TAA remained substantially stable throughout the storage trial.

Quercetin protects C6 glial cells from oxidative stress induced by tertiary-butylhydroperoxide

The anti-oxidant and cyto-protective activity of quercetin against tertiary-butylhydroperoxide (t-BOOH) induced oxidative stress on C6 glial cells is reported. Exposure of the cells to t-BOOH resulted in a significant increase in cytotoxicity, reactive oxygen species (ROS) generation and lipid peroxidation. There was a significant increase in DNA strand breaks and fall in reduced GSH levels in cells exposed to t-BOOH. A significant increase in calcium ion influx was noticed in cells exposed to t-BOOH. Pre-treatment of cells with quercetin, vitamin C (vit C), Trolox, and deferoxamine (DFO) significantly inhibited t-BOOH induced cytotoxicity and ROS generation. Pretreatment of cells with quercetin, Trolox and DFO inhibited the DNA damage, maintained higher GSH levels and prevented calcium influx significantly. Although vit C protected the cells from cytotoxicity induced by t-BOOH, the intracellular Ca(2+) levels were significantly higher than the control cells. However, anti-oxidants like butylated hydroxy toluene (BHT), vitamin E (vit E), N-acetyl cysteine (NAC) did not have significant cytoprotection against t-BOOH induced oxidative injury in C6 glial cells.

Effect of Chokeberry (Aronia melanocarpa) juice on the metabolic activation and detoxication of carcinogenic N-nitrosodiethylamine in rat liver

Chokeberry is a rich source of polyphenols, which may counteract the action of chemical carcinogens. The aim of this study was to examine the effect of chokeberry juice alone or in combination with N-nitrosodiethylamine (NDEA) on phase I and phase II enzymes and DNA damage in rat liver. The forced feeding with chokeberry juice alone decreased the activities of enzymatic markers of cytochrome P450, CYP1A1 and 1A2. NDEA treatment also decreased the activity of CYP2E1 but enhanced the activity of CYP2B. Pretreatment with chokeberry juice further reduced the activity of these enzymes. Modulation of P450 enzyme activities was accompanied by the changes in the relevant proteins levels. Phase II enzymes were increased in all groups of animals tested. Chokeberry juice augmented DNA damage and aggravated the effect of NDEA. These results indicate that chokeberry may protect against liver damage; however, in combination with chemical carcinogens it might enhance their effect.