Biofactors - Volume 27, issue 1-4

Authors: Grootveld, Martin | Algeo, Deborah | Silwood, Christopher J.L. | Blackburn, John C. | Clark, Anthony D.

Article Type: Research Article

Abstract: High resolution ^{1} H NMR spectroscopy has been employed to investigate the detection and quantification of the illicit 'date-rape' drug gamma-hydroxybutyrate (GHB) in both human saliva and a commonly-consumed low-alcohol beer product. Data acquired revealed that this multicomponent analytical technique provided unequivocal evidence for the detection of this agent by this technique in both of these matrices, i.e., all three of its resonances [those ascribable to the α-CH_{2} (t, …δ=2.25 ppm), β-CH_{2} (tt, δ=1.81 ppm) and γ-CH_{2} (t, δ=3.61 ppm) group protons] were present in spectra acquired on human saliva, and two of these (the α- and β-CH_{2} group signals) in the beverage product examined, the latter observation attributable to overlap of the γ-CH_{2} ^{1} H resonance with those of carbohydrates. Since good linear calibration relationships between the intensities of each of the NMR-visible signals and added GHB concentration (the former normalised to that of an external 3-trimethylsilyl [2,2,3,3-^{2} H_{4} ]- propionate standard present in a coaxial NMR tube insert) were observed, this illicit drug is also readily quantifiable in such multicomponent samples. Our data demonstrate the advantages offered by this technique when applied to the analysis of illicit drugs in multicomponent sample matrices such as human biofluids and beverage products. Show more

Citation: BioFactors, vol. 27, no. 1-4, pp. 121-136, 2006

Authors: Choi, Soo-Yeon | Park, Jung Han Yoon | Kim, Jong-Sang | Kim, Mi Kyung | Aruoma, Okezie I. | Sung, Mi-Kyung

Article Type: Research Article

Abstract: Chronic inflammation in gastrointestinal tract has been suggested as a risk factor for tumor formation. The effect of dietary supplementation of quercetin or ß-carotene on colon carcinogenesis and inflammatory response in rats fed with high-fat diet rich in ω-6 fatty acids was assessed. Animals were exposed to two weekly subcutaneous injections of AOM (azoxymethane) at a single dose of 15 mg/kg body weight. A portion of rats from each group was sacrificed at 8 weeks after …the last AOM treatment to determine ACF (aberrant crypt foci) formation. Colonic mucosa expression of iNOS (inducible nitric oxide) and COX-2 (cyclooxygenase-2) protein, and blood PGE_{2} (prostaglandin E_{2} ) level were measured. The remaining groups of animals were sacrificed at 33 weeks after the last AOM treatment to examine colon tumor formation. Rats on high-fat diet developed more aberrant crypt foci (P<0.05) compared with those of rats on regular diet. In the same vein, but in contrast to the effect seen with regular diet, the high-fat diet induced a significant up-regulation of iNOS expression. There was no significant change in the extent of COX-2 expression or in the PGE_{2} levels. Quercetin or β-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05), however, no significant difference in tumor incidence was found. At week 33, the expression of iNOS was reduced by quercetin without a statistical significance, and COX-2 expression was slightly reduced in rats on ß-carotene supplementation. No change in PGE_{2} levels was observed. Whilst dietary antioxidants are considered as effective suppressors for precancerous lesion formation in colons exposed to high-risk diet, it is clear that elucidating the role of individual antioxidants in colon tumor formation coupled with an understanding of the molecular mechanisms involved would benefit colon cancer prevention strategies. Show more

Keywords: Colon cancer, inflammation, antioxidants, quercetin, β-carotene, COX-2, iNOS, high-fat diets

Citation: BioFactors, vol. 27, no. 1-4, pp. 137-146, 2006

Authors: Park, Jung-Ran | Park, Joon-Suk | Jo, Eun-Hye | Hwang, Jae-Woong | Kim, Sun-Jung | Ra, Jeong-Chan | Aruoma, Okezie I. | Lee, Yong-Soon | Kang, Kyung-Sun

Article Type: Research Article

Abstract: Chaga mushroom (Inonotus obliquus) has continued to receive attention as a folk medicine with indications for the treatment of cancers and digestive diseases. The anticarcinogenic effect of Chaga mushroom extract was investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 normal rat liver epithelial cells. The cells were pre-incubated with Chaga mushroom extracts (5, 10, 20 μg/ml) for 24 h and this was followed by co-treatment with Chaga mushroom extracts and TPA …(12-O-tetradecanoylphorbol-13-acetate, 10 ng/ml) for 1 h. The inhibition of GJIC by TPA (12-O-tetradecanoylphorbol-13-acetate), promoter of cancer, was prevented with treatment of Chaga mushroom extracts. Similarly, the increased phosphorylated ERK1/2 and p38 protein kinases were markedly reduced in Chaga mushroom extracts-treated cells. There was no change in the JNK kinase protein level, suggesting that Chaga mushroom extracts could only block the activation of ERK1/2 and p38 MAP kinase. The Chaga mushroom extracts further prevented the inhibition of GJIC through the blocking of Cx43 phosphorylation. Indeed cell-to-cell communication through gap junctional channels is a critical factor in the life and death balance of cells because GJIC has an important function in maintaining tissue homeostasis through the regulation of cell growth, differentiation, apoptosis and adaptive functions of differentiated cells. Thus Chaga mushroom may act as a natural anticancer product by preventing the inhibition of GJIC through the inactivation of ERK1/2 and p38 MAP kinase. Show more

Keywords: Inonotus obliquus (Chaga mushroom), gap junctional intercellular communication, connexin 43, ERK 1/2, p38 MAP kinase, chemoprevention and signaling mechanisms

Citation: BioFactors, vol. 27, no. 1-4, pp. 147-155, 2006

Authors: Xiao, Lianchun | Zhao, Lijun | Li, Ting | Hartle, Diane K. | Aruoma, Okezie I. | Taylor, Ethan Will

Article Type: Research Article

Abstract: The "Long Terminal Repeat" (LTR) of HIV-1 is the target of cellular transcription factors such as NF-κB, and serves as the promoter-enhancer for the viral genome when integrated in host DNA. Various LTR-reporter gene constructs have been used for in vitro studies of activators or inhibitors of HIV-1 transcription, e.g., to show that antioxidants such as lipoic acid and selenium inhibit NF-κB-dependent HIV-1 LTR activation. One such construct is the pHIVlacZ plasmid, with the HIV-1 LTR …driving expression of the lacZ gene (encoding β-galactosidase, β-gal). Typically, for inhibitor screening, cells transfected with pHIVlacZ are activated using tumor necrosis factor-α (TNF-α), and the colorimetric o-nitrophenol assay is used to assess changes in β-gal activity. A variant of this assay was developed as described here, in which LTR activation was induced by pro-fs, a novel HIV-1 gene product encoded via a −1 frameshift from the protease gene. Cotransfection of cells with pHIVlacZ along with a pro-fs construct produced a signifcant increase in β-gal activity over controls. L-ergothioneine dose dependently inhibited both TNF-α-mediated and pro-fs-mediated increases in β-gal activity, with an IC_{50} of about 6 mM. Thus antioxidant strategy involving ergothioneine derived from food plants might be of benefit in chronic immunodeficiency diseases. Show more

Citation: BioFactors, vol. 27, no. 1-4, pp. 157-165, 2006

Authors: Galán, Ana I. | Palacios, Encarna | Ruiz, Francisco | Díez, Arancha | Arji, Mohamed | Almar, Mar | Moreno, Carlos | Calvo, José I. | Muñoz, María E. | Delgado, Marco A. | Jiménez, Rafael

Article Type: Research Article

Abstract: Free radicals and oxidative stress are involved in the pathogenic mechanisms of cardiovascular disease (CVD), diabetes and cancer. Exercise is a useful strategy for preventing CVD but in elderly persons it can enhance oxidative stress, which is why some studies recommend antioxidant supplementation for exercising elderly subjects. This intervention study was performed on 320 elderly subjects following a Geriatric Revitalization Program (GEREPRO) to maintain physical health and reduce CVD risk. GEREPRO was based on …regular exercise concurrent with a nutritional antioxidant treatment based on daily intake of a functional antioxidant food, Biofrutas™. Sustained exercise (10 months, 3 sessions/week) significantly increased cardiorespiratory fitness and plasma HDL-cholesterol; it reduced some predictors of cardiovascular risk (arterial pressure, LDL-cholesterol, total cholesterol/LDL-C, LDL-C/HDL-C), but significantly enhanced some biomarkers of oxidative stress. Concurrent antioxidant supplementation did not produce any ergogenic effects but, meaningfully, enhanced some positive effects of exercise on physical health and the CDV risk index, and it totally prevented the exercise-induced oxidative stress. Our results show that regular and moderate exercise improves cardiorespiratory function and reduces CVD risk in elderly people, while concurrent antioxidant supplementation modulates oxidative insult during exercise in the elderly and enhances the beneficial effects of exercise. Show more

Keywords: Antioxidant vitamins, cardiovascular disease, elderly, exercise, functional antioxidant foods, lipids profile, oxidative stress, VO_{2}max

Citation: BioFactors, vol. 27, no. 1-4, pp. 167-183, 2006

Authors: Wilhelm, Jiří | Fuksová, Hana | Schwippelová, Zuzana | Vytášek, Richard | Pichová, Alena

Article Type: Research Article

Abstract: Free radicals are considered the most important cause of cellular ageing. We have investigated ageing process in the yeast Saccharomyces cerevisiae. We have compared the wild type strain with the mutant cells with constitutively active Ras oncogen, which generates increased amounts of free radicals. Increased generation of oxygen-derived free radicals resulted in the Ras mutant cells accumulation of lipofuscin-like pigments during ageing. Ageing wild type cells did not accumulate lipofuscin-like pigments. This is quite …unique feature among known biological models. It may be caused by increased concentration of alpha tocopherol (the most prominent lipophilic antioxidant) in the wild type cells. In contrast, the Ras mutant cells contained decreased levels of alpha tocopherol even in the young cells. This observation indicates that the increased free radical generation can overwhelm the endogenous antioxidant system. We have documented the involvement of nitrogen-derived free radicals in the yeast metabolism. Protein nitrotyrosine, a marker of the reactive nitrogen species, has significantly increased in the senescent Ras mutant cells. The wild type cells contained basic level of nitrotyrosine corresponding to its concentration found in non-activated mammalian macrophages. Show more

Keywords: Free radicals, lipofuscin-like pigments, nitrotyrosine, yeast, ageing

Citation: BioFactors, vol. 27, no. 1-4, pp. 185-193, 2006

Authors: Yoshida, Yasukazu | Niki, Etsuo

Article Type: Research Article

Abstract: The biological role of lipid peroxidation products has continued to receive a great deal of attention not only for the elucidation of pathological mechanisms but also for their practical application to clinical use as bio-markers. In the last fifty years, lipid peroxidation has been the subject of extensive studies from the viewpoints of mechanisms, dynamics, product analysis, involvement in diseases, inhibition, and biological signaling. Lipid hydroperoxides are formed as the major primary products, however they are …substrates for various enzymes and they also undergo various secondary reactions. In this decade, F2-isoprostanes from arachidonates and neuroprostanes from docosahexanoates have been proposed as bio-markers. Although these markers are formed by a free radical-mediated oxidation, the yields from the parent lipids are minimal. Compared to these markers, hydroperoxy octadecadienoates (HPODE) from linoleates and oxysterols from cholesterols are yielded by much simpler mechanisms from more abundant parent lipids in vivo. Recently, the method in which both free and ester forms of hydroperoxides and ketones as well as hydroxides of linoleic acid and cholesterol are measured as total hydroxyoctadecadienoic acid (tHODE) and 7-hydroxycholesterol (t7-OHCh), respectively, was proposed. The concentrations of tHODE and t7-OHCh determined by GC-MS analysis from physiological samples were much higher than that of 8-iso-prostagrandin F_{2&alpha;} . In addition to this advantage, hydrogen-donor activity of antioxidants in vivo could be determined by the isomeric-ratio of HODE (9- and 13-(Z,E)-HODE/9- and 13-(E,E)-HODE). Show more

Keywords: Lipid peroxidation, oxidative stress, HODE, oxycholesterol

Citation: BioFactors, vol. 27, no. 1-4, pp. 195-202, 2006

Authors: Wilhelmová, N. | Fuksová, H. | Srbová, M. | Miková, D. | Mýtinová, Z. | Procházková, D. | Vytášek, R. | Wilhelm, J.

Article Type: Research Article

Abstract: Transgenic plants with genetically increased or decreased levels of cytokinins were used to investigate the effect of cytokinin level on the production of ethylene, a plant hormone with suggested role in senescence, and the production of nitric oxide, potentially important signalling and regulatory molecule. The production of these gases was followed during the course of leaf development and senescence. The production of ethylene and nitric oxide is under genetic control of genes other than those involved …in regulation of senescence. The difference in basic ethylene and NO levels in different tobacco cultivars was higher than their changes in senescence. The results of this study did not indicate a direct link between ethylene production and cytokinin levels. However, there was a decreased production of NO in senescent leaves. Low cytokinins level was associated with increased NO production during leaf development. Protein nitrotyrosine proved to be a better indicator of the reactive nitrogen species than measuring of the NO production. Higher nitrotyrosine concentrations were found in insoluble proteins than in the soluble ones, pointing to membrane proteins as the primary targets of the reactive nitrogen species. In plants with elevated cytokinin levels the content of nitrated proteins decreased both in soluble and insoluble fractions. This finding indicates an antioxidative function of cytokinins against reactive nitrogen species. Show more

Keywords: Cytokinin, ethylene, leaf ageing, nitric oxide, reactive nitrogen species, nitrotyrosine, tobacco

Citation: BioFactors, vol. 27, no. 1-4, pp. 203-211, 2006

Authors: Seetulsingh-Goorah, Sharmila P.

Article Type: Research Article

Abstract: Extracellular ATP (ATPo) and adenosine are cytotoxic to several cancer cell lines, suggesting their potential use for anticancer therapy. Adenosine causes cytotoxicity, either when added exogenously or when generated from ATPo hydrolysis, via mechanisms which are not mutually exclusive and which involve, adenosine receptor activation, pyrimidine starvation and/or increases in intracellular S-adenosylhomocysteine: S-adenosylmethionine ratio. Given that adenosine also appears to protect against cytotoxicity via mechanisms including immunity against damage by oxygen free …radicals, an understanding of the contribution of adenosine to ATPo-induced cytotoxicity is thus crucial, when considering any potential therapeutic use for these compounds. However, such an understanding has been largely hindered by the fact that many studies have not focused enough on the possibility that both ATPo and adenosine may mediate cytotoxicity in the same system. Such studies can benefit from use a range of ATPo concentrations when assessing the contribution of adenosine to ATPo-induced cytotoxicity. Whilst future molecular and pharmacological studies are needed to establish the nature of the cytotoxic adenosine receptor, it is possible that more than just one adenosine receptor type is involved and that the cytotoxic receptor(s) type is more likely to have a low affinity for adenosine. Activation of the adenosine receptor(s) would thus lead to cytotoxicity only at relatively high adenosine concentrations, while lower adenosine concentrations mediate non-cytotoxic physiological effects. Show more

Keywords: Adenosine, extracellular ATP (ATPo), P1 receptors, P2 receptors, pyrimidine starvation, cytotoxicity, clinical uses

Citation: BioFactors, vol. 27, no. 1-4, pp. 213-230, 2006

Authors: Chien, Xiaoming Xu | Zafra-Stone, Shirley | Bagchi, Manashi | Bagchi, Debasis

Article Type: Research Article

Abstract: Although a large number of transition metals and cations remarkably induce oxidative deterioration of biological macromolecules including lipids, proteins and DNA, the trace element zinc acts as a novel dietary supplement and an essential micronutrient, and serves a wide range of biological functions in human and animal health. Zinc promotes antioxidant and immune functions, stabilizes and maintains the structural integrity of biological membranes, and plays a pivotal role in skin and connective tissue metabolism and repair. …Zinc is an integral constituent of a large number of enzymes including antioxidant enzymes, and hormones including glucagon, insulin, growth hormone, and sex hormones. High concentrations of zinc are found in the prostate gland and choroids of the eye. Zinc deficiency leads to biochemical abnormalities including the impairments of growth, dermal, gastrointestinal, neurologic and immunologic systems. Given its superior bioavailability, antioxidant and immune-enhancing properties, zinc methionine may serve as a novel dietary supplement to promote health benefits in humans and animals. Show more

Keywords: Zinc supplements, micronutrient, human health, animal health, bioavailability, antioxidant, immune-enhancing properties

Citation: BioFactors, vol. 27, no. 1-4, pp. 231-244, 2006