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Plant-based beverages could contain iron but also phenolic compounds (PC) and ascorbic acid, which are considered modulators of iron uptake. We investigated whether iron from almond and coconut beverages can be taken up by Caco-2 cells. The iron content in almond and coconut beverages was 19.20 and 19.34 mg kg−1 dry weight (dw), respectively; PC were 727.71 and 673.11 mg gallic acid equivalents kg−1, respectively; and ascorbic acid 10.96 mg kg−1 and 24.44 mg∙kg−1, respectively. We observed an increase in iron uptake by induction of cellular ferritin at concentrations of 15 and 30 g L−1 (almond) and 30 g L−1 (coconut). Both beverages significantly increased ferritin induction when iron sulfate was added. Thus, these beverages represent iron sources which can either contribute directly to iron supply or indirectly by enhancing absorption of exogenous iron and contribute to decrease the impact of diseases considered public health problems.

This study investigated the effect of Chlorella vulgaris (C. vulgaris) on genotoxicity, cytotoxicity, and apoptosis in Caco-2 and HT-29 cells. C. vulgaris significantly induced DNA damage in both cell lines at a concentration of 200 μg dry matter/mL (comet tail intensity CTI: 24.6 ± 4.7% for Caco-2, 16.6 ± 0.9% for HT-29). The application of processing (sonication, ball-milling) did not affect the genotoxicity negatively and lowered the lipid peroxidation in C. vulgaris preparations. C. vulgaris-induced intracellular formation of reactive oxygen species in human cell lines and might be responsible for the genotoxic effect. A solid fraction mainly triggered the observed DNA damage (CTI: 41.5 ± 1.9%), whereas a hydrophilic (CTI: 7.9 ± 1.7%) and lipophilic (CTI: 10.2 ± 2.1%) fraction revealed a significantly lower tail intensity. C. vulgaris significantly induced DNA damage in both cell lines possibly through intracellular formation of reactive oxygen species; however, it was repaired after a 2 h recovery time or was even avoided at lower concentrations. In addition, none of the preparations indicated an adverse effect on cell proliferation or revealed apoptotic activity.

With regard to its cost-effective cultivation and the composition of high-value nutrients, the diatom Phaeodactylum tricornutum (P. tricornutum) attracts interest for the use in human nutrition. Besides a number of important nutrients, it is rich in carotenoids. Therefore, this study aimed to investigate the potential of P. tricornutum as a carotenoid source for human nutrition. In photoautotrophically produced P. tricornutum biomass the carotenoid constitution, bioaccessibility (in vitro digestion model) and cellular uptake in differentiated Caco-2 cells (Transwell model system) was determined. Furthermore, the influence of sonication on these parameters was investigated. The results indicate that β-carotene, zeaxanthin and fucoxanthin were the main carotenoids found in P. tricornutum. Moreover, these carotenoids showed a good bioaccessibility (β-carotene: 25%, zeaxanthin: 27%, fucoxanthin: 57%), which is further improved by sonication for β-carotene and fucoxanthin. In line with the good bioaccessibility, fucoxanthin was the most abundant carotenoid in Caco-2 cells followed by zeaxanthin. In contrast, β-carotene could not be detected in the cells. The present study demonstrated that P. tricornutum represents a good source of carotenoids, particularly fucoxanthin. Thus, this diatom can contribute to the intake of bioaccessible carotenoids, even without processing. In addition, sonication might be a useful tool to improve the carotenoid bioaccessibility.

UV-C was investigated to inactivate microorganisms in grape must. The aim was to evaluate the effect of UV-C on wine-related yeasts under winery conditions, to investigate the toxicological potential and to analyze the effects on chemical and sensory wine properties. Metschnikowia pulcherrima showed the highest UV-C tolerance, Saccharomyces cerevisiae the lowest. With an initial cell count of 106 cfu/mL, M. pulcherrima required a UV-C dose of >1.2 kJ/L, S. cerevisiae Industrial relevance UV-C treatment is a non-thermal processing technique for the preservation of food. In this study, the applicability of UV-C treatment for the inactivation of spoilage yeast in grape must was demonstrated in pilot scale. The treatment provided sufficient microbial inactivation without having toxicological impact as examined by the Ames test and without causing off-flavor formation in the wines using relevant doses.

Data from epidemiological studies suggest that consumption of red and processed meat is a factor contributing to colorectal carcinogenesis. Red meat contains high amounts of heme, which in turn can be converted to its nitrosylated form, NO-heme, when adding nitrite-containing curing salt to meat. NO-heme might contribute to colorectal cancer formation by causing gene mutations and could thereby be responsible for the association of (processed) red meat consumption with intestinal cancer. Up to now, neither in vitro nor in vivo studies characterizing the mutagenic and cell transforming potential of NO-heme have been published due to the fact that the pure compound is not readily available. Therefore, in the present study, an already existing synthesis protocol was modified to yield, for the first time, purified NO-heme. Thereafter, newly synthesized NO-heme was chemically characterized and used in various in vitro approaches at dietary concentrations to determine whether it can lead to DNA damage and malignant cell transformation. While NO-heme led to a significant dose-dependent increase in the number of DNA strand breaks in the comet assay and was mutagenic in the HPRT assay, this compound tested negative in the Ames test and failed to induce malignant cell transformation in the BALB/c 3T3 cell transformation assay. Interestingly, the non-nitrosylated heme control showed similar effects, but was additionally able to induce malignant transformation in BALB/c 3T3 murine fibroblasts. Taken together, these results suggest that it is the heme molecule rather than the NO moiety which is involved in driving red meat-associated carcinogenesis. Electronic supplementary material The online version of this article (10.1007/s00204-020-02846-8) contains supplementary material, which is available to authorized users.

The lactobacilli associated with a fermented goat milk product from Tajikistan were isolated to characterize their technological properties and antibiotic resistances in order to assess their suitability for development as starter cultures. In this study, twenty three strains were identified by 16S rRNA sequencing as typical dairy-associated lactic acid bacterial strains, i.e. L. plantarum, L. pentosus, L. delbrueckii, L. helveticus and L. paracasei strains. These strains were generally susceptible to most antibiotics tested in this study and this allowed a selection of strains as safe starters. The draft genomes of four representative strains were sequenced and the number of contigs of the four assembled genomes ranged from 51 to 245 and the genome sizes ranged from 1.75 to 3.24 Mbp. These representative strains showed differences in their growth behavior and pH reducing abilities in in vitro studies. The co-inoculation of these Lactobacillus spp. strains together with a yeast Kluyveromyces marxianus MBT-5698, or together with the yeast and an additional Streptococcus thermophilus MBT-2, led to a pH reduction to 3.4 after 48 h. Only in the case of fermentation inoculated with the co-culture, the viscosity of the milk increased noticeably. In contrast, fermentations with single strains did not lead to gelation of the milk and to decrease the pH after 24h. The results of this study provide a comprehensive understanding of the predominant lactobacilli related to Tajikistan fermented milk products.

This study aimed to investigate Chlorella vulgaris (C. vulgaris; phototrophic and mixotrophic), and Phaeodactylum tricornutum (P. tricornutum) as a potential carotenoid source. Feed preparations containing 5, 15, or 25% of these microalgae species were applied to investigate the carotenoid bioaccessibility (in vitro digestion) as well as bioavailability in vivo in C57BL/6J mice. C. vulgaris mainly contains lutein and β-carotene (mixotrophic), whereas P. tricornutum is rich in fucoxanthin, zeaxanthin, and β-carotene. The diet supplemented with 5% P. tricornutum and ingestion of the 15% and 25%-diet of all investigated microalgae species led to an accumulation of carotenoids and derivatives in the liver. The adipose tissue also showed carotenoids after the consumption of P. tricornutum-diets, but not after C. vulgaris ingestion. We could neither observe a significant increase nor impairment of the retinol concentration in the liver. Thus, consumption of a microalgae-enriched diet can contribute to the absorption and accumulation of microalgal carotenoids.

Dietary fiber is a potential replacement for other ingredients such as starch in reformulated extruded breakfast cereals. Analysis of chokeberry pomace powder revealed a total dietary fiber content of 57.8 ± 2 g/100 g with 76% being insoluble, 20% high molecular soluble and 4% low molecular soluble dietary fiber. The fiber polysaccharide composition was analyzed in detail by using a variety of analytical approaches. Extrusion-like processing conditions were studies in a Closed Cavity Rheometer enabling the application of defined thermal (temperature range 100–160 °C) and mechanical treatments (shear rates between 0.1 s−1 and 50 s−1) to chokeberry pomace powder. Application of temperatures up to 140 °C irrespective of the mechanical treatment does not remarkably alter dietary fiber structure or content, but reduces the initial content of total polyphenols by about 40% to a final content of 3.3 ± 0.5 g/100 g including 0.63 ± 0.1 g/100 g of anthocyanins, 0.18 ± 0.02 g/100 g of phenolic acids and 0.090 ± 0.007 g/100 g of flavonols, respectively. The retained polyphenols are fully bioaccessible after in vitro digestion, and antioxidant capacity remains unchanged as compared to the untreated pomace powder. Glucose bioaccessibility remains unaffected, whereas glucose content is reduced. It is concluded that chokeberry pomace powder is a good source of dietary fiber with the potential to partially substitute starch in extruded breakfast cereals.

This study investigated the effect of

Industrial chokeberry pomace is very rich in polyphenols. The main focus here lies on the possible relationship between the particle size of chokeberry milled pomace and an enhanced absorption and transport of polyphenols by Caco-2 cells. Wet milling was used to produce materials with particle size distributions in the micrometre and in the sub-micrometre to nanometre ranges starting from chokeberry pomace. Milled materials with about 50% of the particles with a mean size (x

Industrial chokeberry pomace is very rich in polyphenols. The main focus here lies on the possible relationship between the particle size of chokeberry milled pomace and an enhanced absorption and transport of polyphenols by Caco-2 cells. Wet milling was used to produce materials with particle size distributions in the micrometre and in the sub-micrometre to nanometre ranges starting from chokeberry pomace. Milled materials with about 50% of the particles with a mean size (x50,3) of 223 ± 13 µm (coarse milling) and about 90% of the particles with x50,3 of 160 ± 40 nm (fine milling, sonication) were obtained. None of the milled materials exhibited cytotoxic effects within the tested concentration-ranges. The polyphenol absorption and the transport efficiencies from the fine and the coarse milled materials were similar. Thus, no effect of the particle size upon cellular uptake and transport could be established, but agglomeration of particle during incubation cannot be excluded as the cause. Furthermore, based on polyphenol stability we postulate that direct milling may be applied to valorise the processing by-product from commercial fruit juice production.

Phaeodactylum tricornutum (P. tricornutum) comprise several lipophilic constituents with proposed anti-obesity and anti-diabetic properties. We investigated the effect of an ethanolic P. tricornutum extract (PTE) on energy metabolism in obesity-prone mice fed a high fat diet (HFD). Six- to eight-week-old male C57BL/6J mice were switched to HFD and, at the same time, received orally placebo or PTE (100 mg or 300 mg/kg body weight/day). Body weight, body composition, and food intake were monitored. After 26 days, blood and tissue samples were collected for biochemical, morphological, and gene expression analyses. PTE-supplemented mice accumulated fucoxanthin metabolites in adipose tissues and attained lower body weight gain, body fat content, weight of white adipose tissue (WAT) depots, and inguinal WAT adipocyte size than controls, independent of decreased food intake. PTE supplementation was associated with lower expression of Mest (a marker of fat tissue expandability) in WAT depots, lower gene expression related to lipid uptake and turnover in visceral WAT, increased expression of genes key to fatty acid oxidation and thermogenesis (Cpt1, Ucp1) in subcutaneous WAT, and signs of thermogenic activation including enhanced UCP1 protein in interscapular brown adipose tissue. In conclusion, these data show the potential of PTE to ameliorate HFD-induced obesity in vivo., This work was funded in part by the Spanish Government (Agencia Estatal de Investigacion, MINECO/FEDER, EU), grant AGL2015-67019-P (to AP). The work by AG was supported by a grant (7533-10-5/91/2) from the Ministry of Science, Research and the Arts of Baden-Wurttemberg (MWK). AG also acknowledges generous support by the bioeconomy graduate program BBW ForWerts, supported by the MWK. AG received a travel grant of the DAAD (German Academic Exchange Service). BS is the recipient of a La Caixa Foundation pre-doctoral contract at the Universitat de les Illes Balears.

The microalgae Phaeodactylum tricornutum (PT) is known for its high content of omega-3 fatty acids, which are known to attenuate inflammation. Additionally, this microalga contains other nutrients such as carbohydrates, vitamins, proteins, and carotenoids and therefore could be of interest for animal and human nutrition. Here, we investigated the effects of hexane, ethanolic, and aqueous extracts on lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs) and on the murine macrophage cell line RAW 264.7. Further, the cytotoxicity of the extracts was studied using the MTT assay. The production of pro-inflammatory cytokines was significantly inhibited by the ethanolic and aqueous P. tricornutum extracts but not by the hexane extract. Both at the mRNA and at the protein levels, the aqueous extract inhibited LPS-induced IL-6, IL-1β, TNFα, and COX-2 expression and release by up to 96% (mRNA) and 79% (protein) in a dose-dependent manner. Compared to the aqueous extract, the ethanolic extract was less effective in cytokine inhibition. The production of nitric oxide in RAW 264.7 cells was significantly reduced by all extracts. We showed that the anti-inflammatory effect of P. tricornutum is exerted through inhibition of nuclear factor-κB activation and dependent on the mitogen-activated protein (MAP) kinase pathway. Our data indicate anti-inflammatory effects of the aqueous P. tricornutum extract and provide a basis information on the safety and potential health benefits of P. tricornutum usage for future animal and human nutrition.

Plant and microbial phytases present in raw materials can cause a dephosphorylation of phytate (myo-inositol hexakisphosphate) (InsP6)) during food processing resulting in a broad range of different myo-inositol phosphates such as pentakisphosphate (InsP5) and tetrakisphosphate (InsP4) in foods. Here, we investigated whether the human intestinal epithelium is able to dephosphorylate myo-inositol phosphates (InsP6, InsP5-, InsP4-, InsP3-isomers) using an in vitro model with differentiated human Caco-2 cells cultured on semipermeable inserts. Incubation of InsP6 and an InsP5-isomer with cells for 3 h showed no dephosphorylation of both InsPs. Treatment of cells with a mixture of different InsP4-isomers, however, caused a formation of about 3.5% of an InsP3-isomer (Ins(1,5,6)P3) and treatment with a mixture of different InsP3-isomers caused about 20% formation of InsP2-isomers, respectively. Thus, human intestinal cells can contribute to the dephosphorylation of myo-inositol phosphates of partly deph...

Freshly squeezed apple juice (cultivar Gala) and commercially available naturally cloudy apple juice were treated with UV-C (254 nm, 0–53 kJ/L) using a commercial UV-C processing unit equipped with a Dean flow reactor. In this study the effect of UV-treatment on enzyme activities, as well as possible cytotoxic and genotoxic effects and furan formation in apple juice were investigated. Even at the highest dose applied (53 kJ/L) no significant effect on the activities of polyphenol oxidase, pectin esterase and polygalacturonase could be determined and residual enzyme activities above 95% were observed in all samples. By raising UV-C irradiation dose to 2.1 kJ/L, the upper limit of practical use, a slight increase in furan concentration from 2.3 to 3.7 μg/kg was observed. However, these concentrations are in the range of commercial, heat-treated juices available on the German market. UV-C treated (10.6 kJ/L) and non-treated apple juice showed no cytotoxic effect in the WST-1 assay when added in concentrations up to 20% (v/v). Furthermore, no difference on DNA strand break formations between treated and non-treated apple juice was observed. Thus, despite a slight increase in the concentration of a potentially genotoxic compound such as furan, UV-C treatment at dosages under investigation did not result in any change in the cytotoxic and genotoxic effects of apple juice on intestinal Caco-2 cells. Industrial relevance Ultraviolet treatment is a promising non-thermal technology for enhancing shelf life of liquid food. While the inactivation of food related microorganisms is well investigated little is known about the effect on compounds like enzymes and in particular the cyto- and genotoxicological potential of UV-C treated products. Our results provide useful information and assistance for regulatory authorities regarding risk and quality assessment of the emerging UV-C technology.

The objective was to investigate the applicability of UV-C technology to inactivate yeasts and bacteria in must and wine. Experiments were carried out in vintage 2016 with Riesling musts of different quality containing their natural microflora. Yeasts were tested more resistant to UV-C energy than bacteria. Saccharomyces cerevisiae showed higher tolerance against UV-C irradiation than Hanseniaspora uvarum facilitating new opportunities to control spontaneous fermentations. However, inactivation efficacy was strongly dependent on turbidity of musts and the initial degree of contamination suggesting a shadowing effect of individual germs. Compared with thermal pasteurization, UV-C treatment of must with 1 kJ/L showed similar effects in germ-reduction. While thermal pasteurization significantly decreased aroma precursors in musts, UV-C treatment did not change concentrations of glycosidically-bound C6-alcohols, monoterpenes and C13-norisoprenoids as shown by GC-MS analysis. Applying UV-C technology in wines, it was possible to irreversibly stop ongoing alcoholic fermentation indicating that UV-C treatment is capable to replace SO2 addition to produce wines with residual sugar. Besides inactivation power, UV-C is known for its ability to form powerful off-flavours such as methional or methanethiol. Sensory analysis revealed that the application of UV-C at doses

Eggerthella and Slackia spp. are gut associated bacteria that have been suggested to play roles in host lipid and xenobiotic metabolism. A quantitative PCR method for the selective enumeration of bacteria belonging to either the genus Eggerthella or Slackia was developed in order to establish the numbers of these bacteria occurring in human feces. The primers developed for selective amplification of these genera were tested first in conventional PCR to test for their specificity. Representative species of Eggerthella and Slackia, as well as closely related genera of the Coriobacteriia, were included in the investigation. The selected primers were shown to be capable of specific amplification of species of the genera Eggerthella and Slackia, but not all species of the genera may be amplified by the respective primers. Their use in qPCR experiments to assess the levels of Slackia equolifaciens and Eggerthella lenta in the feces of 19 human volunteers showed they occurred at mean counts of 7 × 10(5) and 3.1 × 10(5) CFU/g for Eggerthella spp. and Slackia spp., respectively. Electron microscopy investigations showed that while E. lenta cells exhibited slender and very regular shaped rods, Slackia cells showed a remarkably pleomorphic phenotype. Both species did not appear to have fimbriae or pili. Some S. equolifaciens cells showed a characteristic "ribbon" of presumably extracellular material around the cells, particularly at the areas of cell division. The two species also differed markedly in their adhesion behavior to Caco-2 cells in cell culture, as E. lenta DSMZ 15644 showed a high adhesion capacity of 74.2% adherence of the bacterial cells added to Caco-2 cells, while S. equolifaciens DSM 24851(T) on the other hand showed only low adhesion capability, as 6.1% of bacterial cells remained bound. Speculatively, this may imply that the ecological compartments where these bacteria reside in the gut may be different, i.e., E. lenta may be associated more with the gut wall, while Slackia may be free living in the lumen.

Microalgae can contribute to a balanced diet because of their composition. Beside numerous essential nutrients, carotenoids are in the focus for food applications. The bioavailability of carotenoids from photoautotrophic-cultivated Chlorella vulgaris (C. vulgaris) and Chlamydomonas reinhardtii (C. reinhardtii) was compared. An in vitro digestion model was used to investigate carotenoid bioaccessibility. Furthermore, the effect of sonication on bioaccessibility was assessed. Lutein was the main carotenoid in both species. C. reinhardtii showed higher amounts of lutein and β-carotene than C. vulgaris. In contrast to C. reinhardtii, no β-carotene and only 7% of lutein were bioaccessible in nonsonicated C. vulgaris. Sonication increased the bioaccessibility of carotenoids from C. vulgaris to a level comparable with C. reinhardtii (β-carotene: ≥ 10%; lutein: ≥ 15%). Thus, C. reinhardtii represents a good carotenoid source for potential use in foods without processing, while the application of processing methods, like sonication, is necessary for C. vulgaris.

Summary The free radical theory of aging postulates that the production of mitochondrial reactive oxygen species is the major determinant of aging and lifespan. Its role in aging of the connective tissue has not yet been established, even though the incidence of aging-related disorders in connective tissue-rich organs is high, causing major disability in the elderly. We have now addressed this question experimentally by creating mice with conditional deficiency of the mitochondrial manganese superoxide dismutase in fibroblasts and other mesenchyme-derived cells of connective tissues in all organs. Here, we have shown for the first time that the connective tissue-specific lack of superoxide anion detoxification in the mitochondria results in reduced lifespan and premature onset of aging-related phenotypes such as weight loss, skin atrophy, kyphosis (curvature of the spine), osteoporosis and muscle degeneration in mutant mice. Increase in p16INK4a, a robust in vivo marker for fibroblast aging, may contribute to the observed phenotype. This novel model is particularly suited to decipher the underlying mechanisms and to develop hopefully novel connective tissue-specific anti-aging strategies.

A diet rich in fruit and vegetables may decrease the risk of cancer. Decrease of endogenous or exogenous genotoxicity by fruit and vegetables may be partly responsible for this effect. Using the Comet assay in a number of in vivo studies, we attempted to identify the fruit and vegetable species, their extracts or isolated compounds able to decrease endogenously or exogenously-induced DNA damage. We found that consumption of apples protected against formation of endogenously oxidized purine bases and increased capacity to protect DNA in lymphocytes in humans. Cloudy apple juice (750 ml, 2 weeks) also showed an increased capacity to protect DNA in humans. Using the1,2-dimethylhydrazine-rat model of carcinogenesis, we demonstrated the anti-genotoxic and anti-carcinogenetic effects of cloudy apple juice but not their fractions. We also observed a significant reduction of irinotecan-induced DNA-strand breaks after a pre-treatment with isolated anthocyans (cyanidin, cyanidin-3-glucoside) and a blackberry extract in rats and demonstrated that daily consumption of tomato oleoresin containing about 15 mg of lycopene decreased endogenous DNA damage. In contrast, 200 g broccoli for 4 weeks or 330 ml carrot juice for 2 weeks had no effect in humans. Also, consumption of 8 servings (about 800 g) of different commonly consumed fruit and vegetables for 4 weeks showed no effect on DNA damage in lymphocytes in humans. These observations indicate that the kind of fruit or vegetable (e.g. apples, blackberries, tomato products) rather than the total amount of different commonly consumed fruit and vegetables is of essential importance for the anti-genotoxic effects in humans.

Microalgae are rich in macronutrients and therefore, they have been proposed as a potential future food source preserving natural resources. Here, we studied safety and bioavailability of algae nutrients in mice. Three microalgae species, Chlorella vulgaris, Nannochloropsis oceanica and Phaeodactylum tricornutum, were studied after ball mill disruption at different doses (5%, 15% and 25% dry weight) for 14 days. In response to all three algae diets, we observed a weight gain similar or superior to that in response to the control diet. No substantial differences in organ weights nor gut length occurred. Protein bioavailability from the algae diets did not differ from the control diet ranging from 58% to 77% apparent biological value. Fat absorption was lower for microalgae compared to soy oil in control diets, albeit still substantial. High liver eicosapentaenoic acid levels were measured following feeding with N. oceanica, the algae richest in omega-3 fatty acids. Neither histological nor serum analyses revealed any heart, kidney or liver toxicity induced by any of the algae diets. Algae-rich diets were thus well accepted, well tolerated and suitable for the maintenance of body weight and normal organ function. No toxicological effects were observed.

Irinotecan is an anticancer agent that stabilizes topoisomerase I/DNA complexes. So far, no test system has been reported for directly determining irinotecan-induced stabilization of topoisomerase I/DNA complexes in organs in vivo. We adapted an 'in vivo complexes of enzyme to DNA' (ICE) bioassay to assess irinotecan activity in the stomach, duodenum, colon and liver of male Wistar rats after a single treatment with irinotecan (100 mg/kg body weight, intraperitoneally). This was compared to the control group receiving 0.9% sodium chloride intraperitoneally. In addition, the DNA strand breaking properties of irinotecan were measured in mucosal cells from the distal colon by single-cell gel electrophoresis (comet assay) to investigate the association of topoisomerase poisoning and DNA damage in vivo. A single dose of irinotecan significantly increased amounts of topoisomerase I covalently bound to DNA in stomach, duodenum, colon and liver. Concomitantly, the irinotecan-treated group showed significantly higher amounts of DNA strand breaks in colon mucosa cells compared to the control group. The ICE bioassay and the comet assay represent two test systems for investigating the impact of topoisomerase I poisons on DNA integrity in colon tissues of Wistar rats.

It is estimated that 75-85% of all chronic diseases are linked to lifestyle-related and environmental factors. The development of colon cancer is positively associated with obesity and inversely associated with the intake of dietary fibre, fruit and vegetable. Apple juice is the most widely consumed fruit beverage in Germany. It contains a specific spectrum of polyphenols and other components that may reduce the risk of colon cancer. Epidemiologic studies suggest an inverse correlation between apple consumption and colon cancer risk, although the mechanisms for these observations are not clear. The present review summarizes the preventive potential of apple juices and different apple constituents on biomarkers related to colon carcinogenesis with special focus on the in vivo evidence and the cancer promoting condition of obesity. However, under the cancer promoting condition of obesity, apple juice did not show cancer-preventive bioactivity. In our experiments a cancer-preventive bioactivity of apple juice is lacking in rats under the cancer-promoting condition of obesity. To further investigate, whether this lack of efficacy observed in obese rats might be representative for obese individuals human intervention studies on high risk groups such as obese or diabetic individuals are of interest and will be conducted.

Cell-matrix interactions are of significant importance for tissue homeostasis of the skin and, if disturbed, may lead to ageing and hyperplastic scar formation. We have studied fibroblasts stably overexpressing manganese superoxide dismutase (MnSOD) with a defined capacity for the removal of superoxide anions and concomitant accumulation of hydrogen peroxide to evaluate the role of enhanced MnSOD activity on the dynamics of cell-matrix interactions in the three-dimensional collagen lattice contraction assay. MnSOD overexpressing fibroblast populated collagen lattices revealed a significantly enhanced contraction compared to collagen lattices populated with vector control cells. The enhanced collagen lattice contraction was in part due to an increase in active TGF-beta1 and the accumulation of H2O2 in MnSOD overexpressing fibroblasts populated collagen lattices. Inhibition of TGF-beta1 signalling by the ALK4,5,7 kinases' inhibitor SB431542 at least partly inhibited the enhanced collagen lattice contraction of MnSOD overexpressing fibroblasts populated lattices. In addition, supplementation of vector control fibroblast populated collagen lattices with recombinant TGF-beta1 concentration dependently enhanced the collagen lattice contraction. In the presence of the antioxidant Ebselen, a mimic of H2O2 and other hydroperoxides/peroxynitrite-detoxifying glutathione peroxidase, collagen lattice contraction and the activation of TGF-beta1 were significantly reduced in collagen lattices populated with MnSOD overexpressing fibroblasts. Collectively, these data suggest that H2O2 or other hydroperoxides or peroxynitrite or a combination thereof may function as important second messengers in collagen lattice contraction and act at least in part via TGF-beta1 activation.

Obesity and energy restriction modulate the development of precancerous aberrant crypt foci (ACF) in animal models of colon cancer.Investigation of the major obesity-associated determinants for ACF-development and underlying mechanisms leading to ACF-modulation, such as changes in DNA damage or colonocytes hyperproliferation.Lean and obese Zucker rats fed ad libitum (a.l.) or obese pair fed (p.f.) were induced with 1,2-dimethylhydrazine (DMH) for colon cancer. Multiple regression analyses were performed to identify major metabolic factors correlated with ACF number and size (aberrant crypts/ACF). DNA damage is analyzed by the comet-assay, epithelial proliferation by immunohistochemistry.Aberrant crypt foci number was significantly elevated in Zucker obese a.l. (205.7+/-65.4 vs. lean 9.5+/-6.3, P0.05) and is reduced by pair feeding in Zucker obese rats (81.4+/-28.5 vs. obese a.l., P0.05). Compared to lean the ACF size was higher in Zucker obese a.l. (2.1+/-0.3 vs. lean 1.3+/-0.2., P0.05) but is not reduced by pair feeding (1.7+/-0.2; P0.05). While ACF number and size were modulated by genotype and/or pair feeding the DMH-induced DNA damage and hyperproliferation in colonocytes did not differ significantly between groups. Regression analysis showed that plasma parameters associated with lipid-metabolism (triglycerides, cholesterol, malondialdehyde) significantly correlated with the ACF number and size while parameters linked to carbohydrate-metabolism (glucose, insulin) were weaker determinants.Obesity or pair feeding-associated modulation of ACF correlate with parameters related to lipid-metabolism but is not accompanied by changes in DNA damage and proliferation.

Food irradiation has been considered as a safe processing technology to improve food safety and preservation, eliminating efficiently bacterial pathogens, parasites and insects. This study aims to characterize the toxicological potential of 2-alkylcyclobutanones (2-ACBs), radiolytic derivatives of triglycerides, formed uniquely upon irradiation of fat-containing food. In irradiated food they are generated proportionally to fat content and absorbed radiation dose. The cyto- and genotoxic potentials of various highly pure synthetic 2-ACBs were studied in bacteria and human cell lines. While pronounced cytotoxicity was evident in bacteria, no mutagenic activity has been revealed by the Ames test in Salmonella strains TA 97, TA 98 and TA 100. In mammalian cells genotoxicity was demonstrated mainly by the induction of DNA base lesions recognized by the Fpg protein as determined by both the Comet Assay and the Alkaline Unwinding procedure. Formation of DNA strand breaks was observed by the Alkaline Unwinding procedure but not by the Comet Assay. The extent of cytotoxicity and genotoxicity were dependent on chain length and degree of unsaturation of the fatty acid chain. Further studies will have to clarify mechanisms of action and potential relevance for human exposure situation.

The present study was performed to compare the effects on antioxidant activity and on DNA damage of organic and conventionally produced apples grown under controlled conditions in human peripheral blood lymphocytes. Six healthy volunteers consumed either organically or conventionally grown apples (Golden Delicious, 1000 g) from two neighboring commercial farms in a double-blinded, randomized, cross-over study. The average content of total identified and quantified polyphenols in the organically and conventionally produced apples was 308 and 321 microg/g fresh weight, respectively. No statistically significant differences in the sum of phenolic compounds or in either of the polyphenol classes were found between the agricultural methods. Consumption of neither organically nor conventionally grown apples caused any changes in antioxidant capacity of low-density lipoproteins (lag time test), endogenous DNA strand breaks, Fpg protein-sensitive sites, or capacity to protect DNA against damage caused by hydrogen peroxide. However, a statistically significant decrease in the levels of endonuclease III sensitive sites and an increased capacity to protect DNA against damage induced by iron chloride were determined 24 h after consumption in both groups of either organic or conventionally grown apples, indicating the similar antigenotoxic potential of both organically and conventionally grown apples.

As recently shown, a cloudy apple juice (CloA) was effective to modulate colon cancer associated parameters in rats treated with 1,2-dimethylhydrazine (DMH). To identify the bioactive substance classes in CloA, we fractionated CloA to yield a total polyphenol (PF) and a cloud (CF) fraction consisting of proteins, fatty acids, polyphenols, and cell wall polysaccharides. Rats received water (control (Cont)) or CloA, PF, and CF separate or combined (PF-CF) ad libitum for 7 weeks starting one week before the first DMH-injection. As determined by comet assay, the DMH-induced genotoxicity in colonocytes of controls (Cont/DMH: 7.7 +/- 0.5%) was significantly reduced by CloA (3.3 +/- 0.3%) but not by any of the fractions. The crypt cell proliferation induced by DMH (Cont/NaCl: 7.5 +/- 0.6%; Cont/DMH: 14.9 +/- 0.8%) was significantly decreased by CloA (9.4 +/- 0.4%), PF (12.4 +/- 0.7%), CF (11.6 +/- 0.4%), and PF-CF (12.4 +/- 0.6%). Although not statistically significant, CloA tended to reduce the number of large aberrant crypt foci (ACF) (Cont/DMH: 19.0 +/- 3.7; CloA/DMH: 12.3 +/- 1.9), while none of the fractions affected ACFs. Neither CloA nor the fractions changed mRNAs of colonic cyclooxygenases (COX-1, COX-2), glutathione-associated enzymes (GST-M2, gamma-GCS, GST-P), the splenocyte CD4/CD8 ratio, natural killer cell activity, and plasma antioxidant status. These results demonstrate that CloA had a higher cancer-preventive potential than the fractions and further, besides PF, identified CF as an additional bioactive fraction of CloA.

Five Lactobacillus plantarum strains and two Lactobacillus johnsonii strains, stemming either from African traditionally fermented milk products or children's feces, were investigated for probiotic properties in vitro. The relationship between the hydrophobic-hydrophilic cell surface and adhesion ability to HT29 intestinal epithelial cells was investigated, and results indicated that especially the L. johnsonii strains, which exhibited both hydrophobic and hydrophilic surface characteristics, adhered well to HT29 cells. Four L. plantarum and two L. johnsonii strains showed high adherence to HT29 cells, generally higher than that of the probiotic control strain Lactobacillus rhamnosus GG. Most strains with high adhesion ability also showed high autoaggregation ability. The two L. johnsonii strains coaggregated well with the intestinal pathogens Listeria monocytogenes Scott A, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Salmonella enterica serovar Typhimurium ATCC 14028. The L. plantarum BFE 1685 and L. johnsonii 6128 strains furthermore inhibited the adhesion of at least two of these intestinal pathogens in coculture with HT29 cells in a strain-dependent way. These two potential probiotic strains also significantly increased interleukin-8 (IL-8) chemokine production by HT29 cells, although modulation of other cytokines, such as IL-1, IL-6, IL-10, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor alpha (TNF-alpha), and transforming growth factor beta (TGF-beta), did not occur. Altogether, our results suggested that L. plantarum BFE 1685 and L. johnsonii BFE 6128 showed good adherence, coaggregated with pathogens, and stimulated chemokine production of intestinal epithelial cells, traits that may be considered promising for their development as probiotic strains.

This study investigated whether a 21.1 km (half-marathon) or a 42.195 km (marathon) run modulates DNA damage, antioxidant capacity in lymphocytes and plasma, and the immune system in healthy hobby runners. Ten and 12 volunteers who completed the Baden-Marathon race in Karlsruhe with a running distance of 21.1 km and 41.195 km, respectively, were assessed 10 days before and immediately after the finish. There was no increase in the levels of endogenous DNA strand breaks immediately after half-marathon or marathon races. A statistically significant increase in the levels of oxidative DNA damage in lymphocytes was found using endonuclease III but not formamidopyrimidine glycolase (Fpg). The resistance of DNA to oxidative damage induced by hydrogen peroxide in isolated lymphocytes was significantly decreased after both races. The levels of plasma antioxidants such as alpha-tocopherol, beta-carotene and lycopene were close to, or higher than, those considered optimal for reducing the risk of cardiovascular diseases and there were no significant changes after the races in antioxidant capacity of LDL (lag-time test) or plasma in ORAC, TEAC or paraoxonase assays. The number and percentage of granulocytes and monocytes able to generate oxidative burst were significantly increased after both races, but the lytic activity of NK cells was significantly increased at the end of the half-marathon; no effect was observed in the marathon runners. Thus, oxidative DNA damage in lymphocytes, decreased the antioxidant capacity to protect lymphocytes against DNA strand breaks and increased the formation of reactive species by phagocytes in well-nourished hobby runners indicating moderate oxidative damage during such high-intensity exercise.

Clear (CleA) and cloudy (CloA) apple juices containing different amounts of analyzed procyanidins and pectin were investigated for preventive effects of colon cancer and underlying molecular mechanisms in F344 rats given intraperitoneal injections of 1,2-dimethylhydrazine (DMH; 20 mg/kg body wt) once a week for 4 weeks. Rats received either water (Cont), CleA or CloA (ad libitum) for 7 weeks starting 1 week before the first DMH injection. CloA inhibited DMH induced genotoxic damage in mucosa cells of the distal colon compared with Cont as investigated by single-cell microgel electrophoresis assay. The mean tail intensity in mucosa cells of DMH-treated controls (Cont/DMH: 6.1+/-0.9%) was significantly reduced by CloA (2.4+/-0.8%; P0.01) but not by CleA intervention (4.1+/-1.2%; P0.05). The crypt cell proliferation index induced by DMH (Cont/NaCl: 10.0+/-0.7%; Cont/DMH: 19.9+/-1.0%; P0.001) was significantly decreased by CleA (15.7+/-0.7%; P0.001) and CloA intervention (11.9+/-0.4%; P0.001). CloA but not CleA significantly reduced the number of large aberrant crypt foci (ACF) consisting of more than four aberrant crypts (AC) (Cont/DMH: 37.4+/-5.4; CleA/DMH: 32.8+/-4.4, P0.05; CloA/DMH: 18.8+/-2.5 ACF; P0.05) and the overall mean ACF size in the distal colon (Cont/DMH: 2.31+/-0.09; CleA/DMH: 2.27+/-0.05; CloA/DMH: 2.04+/-0.03 AC/ACF; P0.05). After treatment with DMH and/or apple juices there were no changes in transcript levels of colonic cyclooxygenase isoforms (COX-1, COX-2) or glutathione-associated enzymes (GST-M2, gamma-GCS, GST-P), the splenocyte natural killer cell activity and plasma antioxidant status. However, CloA but not CleA prevented the DMH-induced reduction of splenocyte CD4/CD8 (T-helper cells to cytotoxic lymphocytes) ratio. Since both formulations contained comparable concentrations and types of monomeric polyphenols, complex polyphenols or non-polyphenolic compounds, such as pectin might be responsible for the stronger cancer-preventive effect by CloA.

The HDL-bound enzyme paraoxonase (PON) protects LDL from oxidation and may therefore attenuate the development of atherosclerosis. We examined the effect of tomato and carrot juice consumption on PON1 activity and lipid peroxidation in healthy young volunteers with different PON1-192 genotypes (Q/R substitution at position 192). In this randomized cross-over study twenty-two healthy, non-smoking men on a low-carotenoid diet received 330 ml/d tomato juice (37·0 mg lycopene, 1·6 mg β-carotene) or carrot juice (27·1 mg β-carotene, 13·1 mg α-carotene) for 2 weeks. Intervention periods were preceded by 2-week low-carotenoid intake. We determined the PON1-192 genotype by restriction fragment length polymorphism–polymerase chain reaction (RFLP-PCR) and measuredex vivoLDL oxidation (lag time), plasma malondialdehyde and PON1 activity at the beginning and end of each intervention period. At baseline, lag time was higher (PP

Increased consumption of tomato products is associated with a decreased risk of cancer. The present study was performed to investigate whether consumption of a tomato oleoresin extract for 2 weeks can affect endogenous levels of DNA single strand breaks in peripheral blood lymphocytes in healthy non-smokers and smokers. We also assessed, the effect of the tomato oleoresin extract on various immunological functions of peripheral blood mononuclear cells. A double-blinded, randomized, placebo-controlled study design was used. Over a period of 2 weeks 15 non-smokers and 12 smokers were given three tomato oleoresin extract capsules daily (each containing 4.88 mg lycopene, 0.48 mg phytoene, 0.44 mg phytofluene and 1.181 mg alpha-tocopherol). The control group received placebos. The baseline level of endogenous DNA damage for non-smokers was slightly (13%) and non-significantly (P = 0.44) lower than that of smokers. Placebo supplementation of non-smokers and smokers for 2 weeks did not significantly affect lycopene plasma levels or DNA damage in either group. Intervention with tomato oleoresin extract resulted in significant increases in total plasma lycopene and resulted in decreased levels of DNA strand breaks of approximately 32 (non-smokers) and 39% (smokers). However, this effect was not statistically significant in either group (P = 0.09 for non-smokers and P = 0.12 for smokers). Analysis of the distribution pattern of DNA strand breaks showed a statistically significant (P < 0.05) increase in the number of comets in class 0 (undamaged) and a decrease in classes 1 and 2 (damaged) after the tomato oleoresin extract intervention in non-smokers. The changes in the smoker group were not statistically significant. Treatment with the tomato extract had no effect on lymphocyte proliferation, NK cell activity, interleukin (IL)-2 production and tumor necrosis factor (TNF)alpha production, but it significantly reduced IL-4 production in smokers (P = 0.009).

Binding of estrogen receptor (ER) to estrogen response element (ERE) induces gene activation and is an important step in estrogen-induced biological effects. Here, we investigated the effects of some dietary phytoestrogens such as the isoflavones genistein and daidzein, its metabolite equol, and the coumestane coumestrol on the binding rate of ERalpha and ERbeta to ERE by a nonradioactive real-time method, the Biacore Technology. ERalpha and ERbeta were able to bind to ERE immobilized on the surface of a sensor chip even in the absence of estrogens. 17beta-Estradiol and phytoestrogens induced an increase in ER binding to ERE in a concentration-dependent manner. 17beta-Estradiol was a more potent activator of binding than the phytoestrogens studied. The concentrations of 17beta-estradiol inducing an increase in the binding response of ERalpha and ERbeta to ERE by 50% (EC(50)) as compared to unliganded ER were 0.03 and 0.01 microM, respectively. Regarding the efficacy of activation of ERalpha, from the most to the least effective compound, the sequence and the EC(50) were as follows: 17beta-estradiol (0.03 microM) > coumestrol (0.2 microM) > equol (3.5 microM) > genistein (15 microM) > daidzein (>300 microM) and for ERbeta 17beta-estradiol (0.01 microM) > coumestrol (0.025 microM) > genistein (0.03 microM) > daidzein (0.35 microM) > equol (0.4 microM). The ratios EC(50)alpha/EC(50)beta were calculated to be for 17beta-estradiol, 3; coumestrol, 8; equol, 8.8; genistein, 500; daidzein > 850. These ratios indicate that genistein and daidzein preferentially activate the binding of ERbeta to ERE. The endogenous hormone 17beta-estradiol as well as coumestrol and daidzein metabolite equol activate the binding of ERbeta to ERE only slightly more effectively than the binding of ERalpha to ERE. Thus, the effect of daidzein can be changed from a specific activator of ERbeta to an activator of both ER isotypes alpha and beta in humans who are able to convert daidzein to equol. While the results of the measurements with ERalpha were in line with the binding affinities of compounds tested for ER, there was a distinct difference between our results and the binding affinities of phytoestrogens for the ERbeta. This leads to the conclusion that phytoestrogens differ not only in their binding affinities for the ER, but also in their potential to increase the rate of receptor binding to the ERE.

Background: A recent prospective cohort study revealed that moderate wine consumption but not consumption of other alcoholic beverages is associated with a decreased risk of common cold. In contrast, wine constituents such as ethanol and polyphenols are known to suppress immunity. Aim of the study: We investigated whether acute intake of a moderate amount of alcohol modulates immune functions in healthy men and whether polyphenols in red wine with antioxidative and immunomodulatory potential induce changes in immune functions that differ from those induced by the consumption of the 12 % ethanol. Methods: Six healthy males with moderate alcohol consumption patterns randomly consumed a single dose of 500 ml of red wine (12 % ethanol), a 12 % ethanol dilution, dealcoholized red wine, and red grape juice, respectively. The following immune functions were measured before beverage consumption and 1, 3, and 24 h later: phagocytic activity and intensity of neutrophils and monocytes, production of tumor necrosis factor-alpha, interleukin-2, and interleukin-4, lymphocyte proliferation, and lytic activity of natural killer cells. Results: Acute consumption of a moderate amount of red wine and of a 12 % ethanol solution had no effect on immune functions in men. Acute consumption of polyphenol-rich beverages (dealcoholized red wine and red grape juice) also did not affect immunity. Conclusions: This study clearly shows that moderate consumption of alcohol at doses which inversely correlate with cardiovascular disease risk has no short-term effect on human immune cell functions. Acute intake of polyphenol-rich beverages such as red grape juice and dealcoholized red wine also does not affect immunity.

Background: The oxidative modification of LDL is considered to play a central role in the pathogenesis of atherosclerosis and coronary heart disease (CHD). Paraoxonase (PON1) protects LDL from oxidation and may therefore retard the developement of atherosclerosis. The PON1–192 polymorphism is associated with diminished PON1 concentrations and an increased risk for CHD in RR-allele subjects. Aim of the study: To investigate the effect of tomato juice consumption on PON1 activity and other parameters related to oxidative stress in healthy elderly subjects. Furthermore, the PON1–192 genotype has been determined in the volunteers in order to see whether possible treatment effects are related to the PON1–192 polymorphism. Methods: Fifty elderly subjects were randomly assigned to control (mineral water) or intervention group (tomato juice). Subjects of the tomato juice group consumed daily 330 mL tomato juice for 8 weeks. Antioxidant status was measured as LDL oxidation, plasma malondialdehyde, ferric reducing ability of plasma (FRAP) and PON1 activity. The PON1–192 polymorphism was determined by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). Plasma carotenoids were analyzed by HPLC. Results: Tomato juice consumption reduced LDL-oxidation and improved antioxidant status in R-allele carriers, but not in the QQ genotype group. PON1 activity increased irrespective of the genotype in both, control and intervention group. Conclusions: The changes in antioxidant status after tomato juice consumption seem to depend on the PON1–192 genotype. Healthy elderly, carrying the R-allele, could specificly reduce their higher cardiovascular risk by changing dietary habits.

Reactive oxygen species (ROS) play a pivotal role in UVA-induced cell damage. As expression of the inducible nitric oxide synthase (iNOS) is a normal response of human skin to UV radiation we examined the role of nitric oxide (NO) as a protective agent during or even after UVA1- or ROS-exposure against apoptosis or necrosis of rat endothelial cells. When added during or up to 2 h subsequent to UVA1 or ROS exposure the NO-donor S-nitroso-cysteine (SNOC) at concentrations from 100-1000 microM significantly protects from both apoptosis as well as necrosis. The NO-mediated protection strongly correlates with complete inhibition of lipid peroxidation (sixfold increase of malonedialdehyde formation in untreated versus 1.2-fold with 1 mM SNOC). NO-mediated protection of membrane function was also shown by the inhibition of cytochrome c leakage in UVA1 treated cells, a process not accompanied by alterations in Bax and Bcl-2 protein levels. Thus, the experiments presented demonstrate that NO exposure during or even after a ROS-mediated toxic insult fully protects from apoptosis or necrosis by maintaining membrane integrity and function.

Peroxynitrite (ONOO−), a potent oxidizing and nitrating species, has been linked to covalent modifications of biomolecules in a number of pathological conditions. InS. cerevisiae, a model eukaryotic cell system, ONOO−was found to be more potent than hydrogen peroxide in oxidizing thiols, inducing heat shock proteins (Hsp70) and enhancing the ubiquitination of proteins. As identified by microsequence analysis following immunoprecipitation with anti-nitrotyrosine antibodies, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was especially susceptible to nitration by ONOO−in yeast cells. The activity of this enzyme was strongly inhibited upon steady-state exposure of the cells to low doses of ONOO−in yeast and in cultured rat astrocytes. Thus, ONOO−is a potent stressor in yeast capable of inducing oxidative damage and protein nitration, with GAPDH being a preferential target protein that is efficiently inactivated.