Agnieszka Bartoszek

The effect of heating and fermenting on antioxidant properties of white cabbage

It is widely believed that natural antioxidants found in food are significantly lost during processing. Nevertheless, it was recently demonstrated that processed fruits and vegetables may retain their antioxidant activity. In the present work, the changes in the overall antioxidant properties as a consequence of fermentation of cabbage and/or heat treatment of cabbage juices and extracts were studied. Fermentation processes as well as heat treatment increased the initial values of antioxidant activity. While a decrease in the antioxidant potential of sauerkraut juice was found for short heat treatments, a partial recovery of these properties was observed by prolonging heating periods. The TLC analysis showed that during fermentation and thermal processes, some substances with reactivity towards Folin-Ciocalteu reagent, hence with possible antioxidant activity, were released. We demonstrated that in contrast to common expectation, typical culinary processing of cabbage increases its antioxidant potency. The gain in antioxidant activity of heated samples coincided with the formation of both F-C reagent reactive compounds as well as brown early Maillard reaction products. This information may encourage the consumption of heat processed cabbage, especially that the release of antioxidants during heating may prevent oxidation of other food components, e.g. fats.

Phenolic composition and antioxidant properties of polish blue-berried honeysuckle genotypes by HPLC-DAD-MS, HPLC postcolumn derivatization with ABTS or FC, and TLC with DPPH visualization

In this study, different Polish cultivars of blue-berried honeysuckles (Lonicera caerulea L.), wild and bog bilberry, were analyzed for bioactive compounds. The chemical properties verified included composition of anthocyanins and other polyphenols, antioxidant activity, and profiles of antioxidants by HPLC postcolumn derivatization or TLC. The antioxidant activities of different blue-berried honeysuckle cultivars were similar to that of wild-growing bilberries (ranging from 170 to 417 μmol TE/g dm in ABTS and from 93 to 166 μmol TE/g dm in DPPH and Folin-Ciocalteu tests). The major anthocyanin in the blue-berried honeysuckle was cyanidin-3-glucoside, which constituted 84-92% of the total anthocyanins. The TLC and HPLC postcolumn antioxidant profiles indicated that anthocyanins are the major antioxidants in all berries studied. Wild berries and the cultivars of the blue-berried honeysuckles are also a similar source of such minerals as K, Mg, and Ca.

DNA methylation in cancer development, diagnosis and therapy—multiple opportunities for genotoxic agents to act as methylome disruptors or remediators

The role of DNA methylation and recently discovered hydroxymethylation in the function of the human epigenome is currently one of the hottest topics in the life sciences. Progress in this field of research has been further accelerated by the discovery that alterations in the methylome are not only associated with key functions of cells and organisms, such as development, differentiation and gene expression, but may underlie a number of human diseases, including cancer. This review describes both well established and more recent observations concerning alterations in the methylome, i.e. the global and local distribution of 5-methylcytosines, involved in its normal functions. Then, the changes in DNA methylation pattern seen in cancer cells are discussed in the context of their utilisation in cancer diagnostics and treatment. On this basis, comparisons are made between natural covalent DNA modification and that induced by genotoxic agents, chemical carcinogens and antitumour drugs as regards their impact on epigenetic mechanisms. The available data suggest that DNA damage by genotoxins can mimic epigenetic markers and in consequence disrupt the proper function of the epigenome. On the other hand, the same processes in cancer cells, e.g. DNA demethylation as a result of DNA methyltransferase blocking or the induction of DNA repair by DNA adducts, may restore the activity of hypermethylated anticancer genes. The observed multiple mechanisms by which genotoxic agents directly affect methylome function suggest that chemical carcinogens act primarily as epigenome disruptors, whereas mutations are secondary events that occur at later stages of cancer development when genome-protecting mechanisms have already been deregulated.

Convenient identification of desulfoglucosinolates on the basis of mass spectra obtained during liquid chromatography–diode array–electrospray ionisation mass spectrometry analysis: Method verification for sprouts of different Brassicaceae species extracts☆

Over the past decade, glucosinolates (GLs) present in different tissues of Brassicaceae and their breakdown products, especially isothiocyanates formed after myrosinase catalyzed hydrolysis, have been regarded as not only environment friendly biopesticides for controlling soilborne pathogens, but most importantly as promising anticarcinogenic compounds. For these reasons, the identification and quantitative determination of the content of individual glucosinolates in plant material is of great interest. Among the different analytical approaches available today for determining GLs in brassica plant samples, HPLC analysis of their desulfo derivatives (DS-GLs) according to ISO 9167-1, 1992, method is the most widely used. However, the notorious lack of commercially available standards limits its usefulness. To overcome these limitations, liquid chromatography-electrospray ionisation-mass spectrometry was investigated as a potential method for the identification of DS-GLs. The characteristic pattern of fragmentation either in positive or negative ionisation was established based on mass spectra of 11 DS-GL standards, then proposed for additional over 30 most common desulfated GLs. The applicability of MS detection of DS-GLs was verified for real plant samples, the extracts of 14 kinds of brassica sprouts. The results indicated that this methodology combines a convenient identification of DS-GLs with the well established analytical procedure preferred by many researchers. Thus, incorporation of MS detection into popular ISO method seems to result in an improved and more reliable approach to GLs determination.

The dose‐dependent influence of zinc and cadmium contamination of soil on their uptake and glucosinolate content in white cabbage (Brassica oleracea var. capitata f. alba)

The relationship between the ability to accumulate heavy metals (represented by Cd and Zn) and to synthesize bioactive compounds (represented by glucosinolates [GLS]) was investigated in two cabbage cultivars. Plants were grown in the greenhouse of a phytotron under controlled conditions in soils spiked with two different Zn or Cd concentrations. The measurements of Cd and Zn contents in soil and cabbage (leaf) samples were performed by atomic absorption spectroscopy, whereas GLS levels in cabbage were determined by high-performance liquid chromatography. The ranges of metal contents in soil were 80 to 450 mg/kg dry weight for Zn and 0.3 to 30 mg/kg dry weight for Cd, whereas the levels of accumulated Zn and Cd in cabbage amounted to 15 to 130 and 0.02 to 3 mg/kg dry weight, respectively. After initial symptoms of toxicity, during a later stage of growth, the plants exhibited very good tolerance to both metals. Enhanced biosynthesis of GLS was observed in a dose-dependent manner following exposure to the heavy metals. The GLS content in Zn-exposed cabbage rose from 3.2 to 12 µmol/g dry weight, and the corresponding values for Cd-treated plants were 3.5 to 10 µmol/g dry weight. Thus, the increased soil contamination by metals caused greater accumulation in cabbage, as well as stimulation of GLS biosynthesis. The results obtained point to the high phytoremediation and biofumigation potential of white cabbage.

The Optimisation of Analytical Parameters for Routine Profiling of Antioxidants in Complex Mixtures by HPLC Coupled Post-column Derivatisation

INTRODUCTION The wide application of natural and artificial antioxidants in the food, cosmetic and pharmaceutical industries as well as the recognition of the importance of food antioxidants for supporting human health have created a demand for reliable and industrially applicable methods of determining antioxidative activity. This requirement can be fulfilled with the recently proposed HPLC-post-column derivatisation approach, enabling rapid measurements of antioxidative potential along with profiling antioxidants in complex mixtures. OBJECTIVE To employ the commercially available post-column derivatisation device for the on-line detection of antioxidants and to optimise analytical parameters enabling its application for routine profiling of antioxidants in complex mixtures such as those of plant or food origin. METHODOLOGY The mixtures of standards and fruit extracts were resolved using an optimised HPLC method followed by the on-line derivatisation of analytes in a PCX post-column derivatisation instrument. Such parameters as the type of indicator reagent (ABTS, DPPH, Folin-Ciocalteu), its concentration and the temperature of the derivatisation reaction were investigated. The determinations of the Trolox equivalents (TE) values were compared with those obtained by corresponding bulk spectrophotometric tests. RESULTS The study confirms that the commercial HPLC-coupled post-column derivatisation instruments are suitable for routine on-line detection of antioxidants in complex mixtures and the determination of their TE values. The analytical parameters optimised here appear to represent a ready-to-use toolbox for the food and pharmaceutical industries, enabling the monitoring of bioactive substances along the production line and during storage, and the characterisation of plant material by creating chromatographic profiles supplemented with antioxidant fingerprints.

Carcinogenic and anticarcinogenic food components

Food and Cancer: Development of an Association, K. (Chris) Szyfter and J. Gawecki Molecular Mechanisms of Carcinogenesis, Danuta Malejka-Giganti and Natalia Tretyakova Metabolism of Chemical Carcinogens, Zofia Mazerska Genotoxic Food Components, Agnieszka Bartoszek Impact of Food Preservation, Processing, and Cooking on Cancer Risk, Amanda J. Cross and Rashmi Sinha Environmental Contamination of Food, Marek Biziuk and Agnieszka Bartoszek Dietary Anti- and Prooxidants: Their Impact on Oxidative DNA Damage and Cancer Risk, Ryszard Olinski, Daniel Gackowski Marcus S. Cooke, and Joe Lunec Dietary Polyunsaturated Fatty Acids, Eicosanoids, and Intestinal Tumorigenesis, Jay Whelan, Michael F. McEntee, and Seung J. Baek Chemoprevention of Cancer: Basic Mechanisms and Molecular Targets, Wanda Baer-Dubowska and Ewa Ignatowicz Chemopreventive Phenolic Compounds in Common Spices, Young-Joon Surh Cancer Prevention by Tea and Tea Constituents, Janelle M. Landau, Joshua D. Lambert, Mao-Jung Lee, and Chung S. Yang Cancer Chemoprevention by Wine Polyphenols and Resveratrol, John M. Pezzuto, Tamara P. Kondratyuk, and Elena Shalaev Flavonoids: Common Constituents of Edible Fruits and Vegetables, Nicole Monfilliette-Cotelle Carotenoids in Cancer Prevention, Cristina Fortes Chemopreventive Potential of Compounds in Cruciferous Vegetables, Ole Vang Phytoestrogens and Their Effects on Cancer, Grzegorz Grynkiewicz and Adam Opolski Diet and Cancer Prevention: Current Knowledge and Future Direction, Elizabeth H. Jeffery and John A. Milner Index

The influence of selenium addition during germination of Brassica seeds on health-promoting potential of sprouts

Abstract The correlation among selenium uptake, the content of bioactive compounds in sprouts, and biological activities triggered in cultured human cells by sprout extracts was investigated. Seeds of Brassica crops and rye were treated with SeO2 water solution. The selenium levels in sprouts increased from 1.0–4.1 to 53.3–382 μg/g dw with no influence on plant physiology according to the indices used. Neither the composition of glucosinolates (GL) in Brassica sprouts nor the myrosinase activity nor the composition of GL breakdown lipophilic products were significantly affected. In all Brassica sprouts, conversion to health-promoting isothiocyanates (ITC) and indoles corresponded to only 1% of total GLs. Low ITC concentration may explain observed lack of induction of glutathione S-transferases (GST) and quinone oxidoreductase (NQO) detoxifying enzymes in HT29 cells exposed to sprout extracts. The insignificant impact on cell growth and genome function suggests that Brassica sprouts may be safe vehicle of selenium to combat its dietary deficiency.

Modulation of CYP1A1, CYP1A2 and CYP1B1 Expression by Cabbage Juices and Indoles in Human Breast Cell Lines

Epidemiological studies have shown that consumption of cabbage and sauerkraut is connected with significant reduction of breast cancer incidences. Estrogens are considered a major breast cancer risk factor and their metabolism by P450 enzymes substantially contributes to carcinogenic activity. The aim of this study was to investigate the effect of cabbage and sauerkraut juices of different origin on the expression profile of the estrogen metabolism key enzymes (CYP1A1, CYP1A2, CYP1B1) in breast cell lines MCF7, MDA-MB-231, and MCF10A. The effects of cabbage juices were compared with that exerted by indole-3-carbinol (I3C) and 3,3′-diindolylmethane (DIM). The treatment with cabbage juices or indoles for 72 h affected the expression of CYP1 family genes in cell-type dependent manner. Their induction was found in all cell lines, but the ratio of CYP1A1 to CYP1B1 was 1.22- to 10.6-fold in favor to CYP1A1 in MCF7 and MCF10A cells. Increased levels of CYP1A2 in comparison with CYP1B1 were also observed in MCF7 cells. In contrast, in MDA-MB-231 cells CYP1B1 was preferentially induced. Since the cell lines investigated differ in invasion capacity, these results support epidemiological observations and partly explain the mechanism of the chemopreventive activity of white cabbage products.

Determination of Glucosinolates and Their Decomposition Products—Indoles and Isothiocyanates in Cruciferous Vegetables

Several epidemiological studies have shown that a high intake of cruciferous vegetables, for example cabbage, broccoli or Brussel sprouts has beneficial influence on human health. Consumption of these vegetables is related to a lower risk of several cancers. Bioactive compounds such as glucosinolates and products of their decomposition—isothiocyanates and indoles—have an influence on anti-cancer properties. However, there is poor information about methods of detrmination of these compounds present in cruciferous vegetables. A significant analytical challenge for scientists is to gain reliable data about the presence and quantity of compounds with anti-cancer properties in samples of vegetable material. The purpose of this review is to present and introduce advantages and disadvantages of different methods of determination of glucosinolates, isotiocyanates and indoles present in cruciferous vegetables. High-performance liquid chromatography is general technique of analysis of glucosinolates, indoles and total isotiocyanates content. Identification of isothiocyanates from plant samples is accomplished by gas chromatography.