Endocrine disrupters are strictly associated to cancer and several cardiovascular risk factors. Bisphenol A (BPA) is an endocrine disrupter commonly used in the manufacturing of plastics based on polycarbonate, polyvinyl chloride and resins. Our study aims to investigate whether BPA may cause pro-oxidative and pro-inflammatory effects on cardiomyoblasts, thus exacerbating the Doxorubicin (DOXO)-induced cardiotoxicity phenomena. We tested the metabolic effects of BPA at low doses analyzing its affections on the intracellular calcium uptake, oxidative stress, lipid peroxidation and production of nitric oxide and interleukins. Co-incubation of BPA and DOXO significantly reduced the cardiomyoblast viability, compared to only DOXO exposure cells. The mechanisms underlying these effects are based on the stimulation of the intracellular calcium accumulation and lipid peroxidation. Notably, BPA increase the production of pro-inflammatory interleukins involved in cardiovascular diseases as well as in DOXO-Induced cardiotoxicity phenomena. This study provides a rationale for translational studies in the field of cardio-oncology.
Mytilus galloprovincialis female specimens were collected from two mussel farms located in two sites next to Castel dell'Ovo, a historical complex located in the Naples Bay. Such sites were named, respectively, A-area and B-area for the different microbiological parameters so that mussels from A-area can be sold without purification, whereas mussels from B-area must be purified before sale. The mussels were collected during the nonreproductive (summer 2009) and reproductive periods (autumn 2009). Gonadosomatic index, structural organization of the ovary, presence of apoptosis, estrogen receptors expression, as well as the bisphenol A (BPA) content in the ovaries, were evaluated. Ovaries from specimens collected in area B showed a different and significant distribution of the investigated biomarkers as well as of BPA content in respect to those measured in the A-area specimens, confirming that mussels are valid sentinel organisms to biomonitor in the Naples bay too.
The degradation and mineralization of the nonionic surfactant octylphenol ethoxylate (OPEO), commercially known as Triton™ X-45, by the peroxymonosulfate (PMS)/UV-C process were investigated. Three different toxicity tests ( Daphnia magna , Vibrio fischeri and Pseudokirchneriella subcapitata ) as well as the Yeast Estrogen Screen (YES) bioassay were undertaken to evaluate the potential toxic and estrogenic effects of OPEO and its oxidation products. OPEO removal was very fast and complete after 7 min via PMS/UV-C treatment under the investigated reaction conditions (OPEO = 20 mg L^−1 (47 μM); TOC = 12 mg L^−1; PMS = 2.5 mM; initial reaction pH = 6.5; applied UV-C dose = 21 Wh L^−1). TOC removal also proceeded rapidly; a gradual decrease was observed resulting in an overall TOC removal of 84%. The toxic responses of PMS/UV-C treated OPEO solutions varied according to the test organism used in the bioassay. Daphnia magna was found to be most sensitive to aqueous OPEO, whereas Pseudokirchneriella subcapitata appeared to be the least sensitive one. Daphnia magna and Vibrio fischeri tests revealed that the inhibitory effect of OPEO decreased significantly during the course of treatment. On the other hand, PMS/UV-C oxidation products exhibited a high toxic effect towards Pseudokirchneriella subcapitata (around 60%). YES test results underlined the need for improving the PMS/UV-C treatment performance to remove the estrogenic activity of OPEO and its oxidation products.
The metabolic effects induced by feed contaminated with a lower or a higher concentration of -nonylpnenol (NP), 4-tert-octylphenol (t-OP) or bisphenol A (BPA), three environmental endocrine disruptors, were assessed in juvenile sea bream liver. Histological analysis demonstrated that all these three xenobiotics induced hepatic lipid accumulation and steatosis. These findings prompted analysis of the expression of the major molecules involved in lipid metabolism: peroxisome proliferator activated receptors (which is encoded by ppars), fatty acid synthase (encoded by fas), lipoprotein lipase (encoded by lpl) and hormone-sensitive lipase (encoded by hsl). The enzymes encoded by ppars and fas are in fact responsible for lipid accumulation, whereas lpl- and hsl- encoded proteins play a pivotal role in fat mobilization. The three xenobiotics modulated ppar mRNA expression: pparα mRNA expression was induced by the higher dose of each contaminant; pparβ mRNA expression was upregulated by the lower doses and in BPA2 fish ppary mRNA overexpression was induced by all pollutants. These data agreed with the lipid accumulation profiles documented by histology. Fas mRNA levels were modulated by the two NP doses and the higher BPA concentration. Lpl mRNA was significantly upregulated in all experimental groups except for BPA1 fish while hsl mRNA was significantly downregulated in all groups except for t-OP2 and BPA1 fish. The plasma concentrations of cortisol, the primary stress biomarker, were correlated with the levels of pepck mRNA level. This gene encodes phosphoenolpyruvate carboxykinase which is one of the key enzymes of gluconeogenesis. Pepck mRNA was significantly overexpressed in fish exposed to NP2 and both t-OP doses. Finally, the genes encoding cyclooxygenase 2 (cox2) and 5-lipoxygenase (5 lox), the products of which are involved in the inflammatory response, transcriptions were significantly upregulated in NP and BPA fish, whereas they were unchanged in t-OP specimens. The present findings suggest that dietary xenobiotic contamination can give rise to metabolic disorders also in fish and highlight the potential for their vertical transfer through the trophic levels and ultimately to humans.
A wide range of endocrine disrupter chemicals can mimic steroid hormones causing adverse health effects. Nonylphenol (NP) and t-octhylphenol (t-OP) are man-made alkylphenolic environmental contaminants possessing controversial endocrine disruption properties. This study has investigated the effects of NP and t-OP enriched diets on hepatic tissue and biotransformation activities in the liver. To this aim, sea bream juveniles were fed with commercial diet enriched with three different doses of NP (NP1: 5mg/kg bw, NP2: 50mg/kg bw and NP3: 100mg/kg bw) or t-OP (t-OP1: 5mg/kg bw, t-OP2: 50mg/kg bw and t-OP3: 100mg/kg bw) for 21 days. A significant increase of the hepatosomatic index was observed in NP1 and t-OP1. Alteration of liver morphology was observed in both NP and t-OP exposed juveniles although the most altered endpoints were observed in t-OP2 with 100% of tissue degeneration. Ethoxyresorufin-O-deethylase activity was significantly inhibited by NP and t-OP (p<0.05), while catalase activity was significantly induced, at both doses. A different pattern of protein expression of different isoforms of both vitellogenin and zona radiata protein was evidenced within the treatments. In addition, a significant increase in the abundance of the stress induced heat shock protein 70 gene in the liver of t-OP2 fish and a significant increase in the abundance of the estrogen induced cathepsin D gene in the liver of NP1 and t-OP2 fish, were observed. Finally, estradiol-17β (E2) and testosterone (T) plasma levels and E2/T showed significantly different patterns in NP and t-OP exposed against control fish.
Immobilized enzymes offer many advantages over the free counterparts. These advantages include, but are not limited to, easy separation, reuse, induced stabilities and potential of continuous operation. However, the immobilization process at the same time causes some drawbacks including loss of catalytic activity of the immobilized enzymes. Many interpretations have been given to explain the reasons behind such drawback. Some of them are related to the enzymes themselves, such as deactivation of enzymes and miss-orientation. Others refer to diffusion limitation of substrates and/or to inhibitory effects of the products. Substrate diffusion limitation presents the most serious one. In this review some strategies for overcoming this drawback are reported. Among these strategies are the ones related to enzyme immobilization on: a) soluble-insoluble matrices, b) thermally reversible hydrogels, c) pressure-sensitive gels, d) on catalytic hydrophobic membranes operating under non-isothermal conditions, and finally, on carriers' surface, are presented and discussed. Keywords: Activity decay, diffusion limitation, easy separation, enzymes immobilization, inhibition, non-isothermal bioreactors, pressure-sensitive gels, products, reuse ability, soluble-insoluble matrices, stabilities, substrates, surface immobilization, thermally reversible hydrogels.
The relevance of Bisphenol A (BPA) in human health is well-known. For this reason we designed and developed a biosensor based on a bionanocomposite (laccase-thionine-carbon black)-modified screen-printed electrode. Thionine, a commercially available dye, was used as electrochemical mediator coupled with a nanostructured carbon black. By means of cyclic voltammetry, the interaction of thionine adsorbed on modified screen printed electrode with laccase/BPA reaction products has been studied. In addition, the immobilization of laccase by physical adsorption on the surface of thionine-carbon black modified screen printed electrodes was investigated. The response of the biosensor has been optimized in terms of enzyme loading, pH and applied potential reaching a linear concentration range of 0.5-50 mu M, a sensitivity of 5.0 +/- 0.1 nA/mu M and a limit-of-detection (LOD) of 0.2 mu M. The developed biosensor has been also challenged in tomato juice samples contained in metallic cans where release of BPA due to the epoxy resin coating can be assumed. A satisfactory recovery value comprised between 92% and 120% was obtained. (C) 2013 Elsevier Ltd. All rights reserved.
The oxidative biodegradation of 2- and 4-chlorophenol (CPs) catalyzed by immobilized laccase from Trametes versicolor was conducted in a bed reactor. The effects of reaction conditions (reaction time, dosage of immobilized enzyme, flow rate, pH value and temperature, initial concentration) on CPs removal efficiency (RE) were investigated. By using in the immobilization solution an enzyme dosage of 2.5 mg(free) (enz)g(carrier)(-1), the maximum ratio of laccase to PAN-beads is resulted 0.25 mg(immenz)g(carrier)(-1).RE values greater than 70% were obtained when 40 mL of 1 mM substrate solution were circulated for 90min at 75 mL min(-1) in the bed reactor filled with 12 g of laccase-PAN beads. The optimal pH for CPs biodegradation was 5 and it was not related to substituent position on aromatic ring. Experiments with immobilized laccase demonstrated good removal at high initial substrate concentrations and high thermal stability. The affinity of 2-CP was higher than that of 4-CP.Finally, the 2-CP was also biodegraded as tertiary mixtures with 2,3,4,5-tetrachlorophenol (TCP) and pentachlorophenol (PCP). The presence of TCP and PCP decreased the removal efficiency of 2-CP. The order of the relative degrading capacity becomes TCP > PCP > 2-CP. (C) 2012 Elsevier B.V. All rights reserved.
Laccases are cuproproteins belonging to the group of oxidoreductases that are able to catalyze the oxidation of various aromatic compounds (particularly phenols) with the concomitant reduction of oxygen to water. They are characterized by low substrate specificity and have a catalytic competence which widely varies depending on the source. Additionally, laccases have also very peculiar optical properties due to their copper active sites which participate to the reduction processes. All these characteristics make laccases very flexible biotic element for biotechnological applications. During the years, a number of studies have been devoted at exploiting catalytic properties of laccases and very few at profiting of their optical properties. Some preliminary studies by absorption, fluorescence FT-IR and Raman spectroscopies of commercial laccases have evidenced their potential usefulness for optical biosensing of phenol compounds as cathecol. Moreover the sol-gel process offers a convenient and versatile method for preparing optically transparent matrices at room temperature that can represent a very convenient support for laccase immobilization. Also for immobilised enzymes the above-mentioned techniques have allowed a detailed characterization of their optical properties that confirmed the potentials of laccases in optical biosensors and represented a fundamental step in the designing of an optimised optical biosensing scheme.
Endocrine disruptor chemicals (EDCs), which are predominantly present in the environment, are able to mimic or antagonise the biological activity of hormones primarily through the interaction with specific receptors. The main consequences are adverse effects on the growth and development of reproductive organs, the induction of cancer and effects on neuronal differentiation. In this study, we investigated the ability of certain EDCs, Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol F (BPF), 4-n Nonylphenol (NP) and Octylphenol (OP), belonging to a homogeneous group of phenol origin, to interfere with specific cellular processes, namely, proliferation, by using MCF-7 breast carcinoma cells, and differentiation, by using murine bone marrow dendritic cells. We correlated the data on cell growth with the stimulation of cell cycle progression, which could become a step in the development of cancer, and we established a proliferation ranking between the tested EDCs: NP>BPA>OP>BPB>BPF. In addition, we investigated the ability of NP, BPA and OP to induce the differentiation of dendritic cells, the powerful antigen-presenting cells of the immune system. The differentiation and activation of these cells could affect a well-regulated immune response and determine an allergic sensitisation. We found that BPA and NP were active in determining differentiation.
Glucose oxidase (GOD) immobilized into sol-gel matrices was studied by using Micro-Attenuated Total Reflection Fourier Transform Infrared (micro-ATR FT-IR) spectroscopy in order to characterize enzyme distribution and secondary structure in systems with valuable potentialities in amperometric and optical biosensing. Spectra were acquired in the 4000-600 cm(-1) frequency region and the analysis of specific fingerprints in the FT-IR spectra evidenced that the enzyme was actually immobilized in the matrix. The enzyme spatial distribution was obtained by examining the amide I and amide II band region of spectra from defined sample positions. The deconvolution of the amide I band in terms of lorentzian functions provided information on the secondary structure of the immobilized GOD. By this approach a macroscopic preservation of GOD activity upon immobilization was evidenced along with the existence of some matrix sites with locally inactivated GOD. To our knowledge this is the first example of point-by-point characterization of conformational changes of immobilized enzyme by means of micro-ATR infrared spectroscopy, thus confirming that this technique can be usefully employed for a non- or minimally-invasive detailed micro-characterization of catalytic supports in order to improve their functionality.
The potential of Raman spectroscopy with excitation in the visible as a tool for quantitative determination of single components in food industry products was investigated by focusing the attention on glucose content in commercial sport drinks. At this aim, micro-Raman spectra in the 600–1600cm−1 wavenumber shift region of four sport drinks were recorded, showing well defined and separated vibrational fingerprints of the various contained sugars (glucose, fructose and sucrose). By profiting of the spectral separation of some peculiar peaks, glucose content was quantified by using a multivariate statistical analysis based on the interval Partial Least Square (iPLS) approach. The iPLS model needed for data analysis procedure was built by using glucose aqueous solutions at known sugar concentrations as calibration data. This model was then applied to sport drink spectra and gave predicted glucose concentrations in good agreement with the values obtained by using a biochemical assay. These results represent a significant step towards the development of a fast and simple method for the on-line glucose quantification in products of food and beverage industry.
Pregnant adult Balb-C mice were exposed daily to two different doses of Bisphenol A (BPA) by subcutaneous injection beginning on gestational day 1 through the seventh day after delivery. The mothers were sacrificed on postpartum day 21, and the offspring were sacrificed at 3 months of age. Control mice were subjected to the same experimental protocol but received saline injections. The liver, muscles, hindbrain and forebrain of the offspring were dissected and processed using HPLC to assess the level of BPA in the tissues and to determine its dependence on the exposure dose and gender. For comparison, the same tissues were dissected from the mothers and analysed. We report the following results: (1) the level of BPA that accumulated in a given tissue was dependent on the exposure dose; (2) the rank order of BPA accumulation in the various tissues was dependent on the gender of the offspring; (3) the average BPA concentrations in the liver and muscle of the female offspring were higher than in the males; and (4) the average BPA concentration in the central nervous system (i.e., the hindbrain and forebrain) of the male offspring was higher than in the females.
Octylphenol (OP) is an endocrine-disrupting chemical that accumulates in various organs. It has also been shown to exert noxious effects on the central nervous system. In the present study, we measured in Sprague-Dawley rats the degree of OP accumulation in different areas of the brain and investigated the effect of OP in pain modulation.Two groups of male Sprague-Dawley rats were treated for 20 days with 50 mg/kg BW/day of OP (group 1) or vehicle (group 2). At the end of the treatment, the formalin test was performed to evaluate the effect of OP exposure on pain. Soon after, rats were sacrificed, and the accumulation of OP in the cerebral cortex, hippocampus, hypothalamus, cerebellum, thalamus, striatum, mesencephalus and ventral hindbrain was measured by HPLC analysis. The results showed a greater accumulation of OP in the cerebral cortex compared to all the other areas; there was also more accumulation in the cerebellum compared to the mesencephalus and thalamus. No accumulation was found in the striatum. These results suggest that there is a preferential accumulation of OP in different areas of the brain with consequences to neural behaviour.On the contrary, experiments on facial grooming did not show significant effects of OP on pain. (C) 2010 Elsevier B.V. All rights reserved.
Micro-Attenuated Total Reflection (ATR) Fourier Transform Infrared spectroscopy was used to investigate sol–gel layers for biosensing applications prior and after glucose oxidase (GOD) immobilization. The changes occurring in sol–gel infrared spectrum after GOD immobilization were clearly evidenced confirming the retaining of the enzyme activity. Moreover, micro-ATR experimental technique allowed us to investigate the spatial distribution of enzyme concentration. The non-destructive nature of our approach also enabled to monitor the time stability of sol–gel layers and of embedded GOD. The temporal evolution of some peaks in infrared spectra of these sol–gel layers was compared with absorption and steady-state fluorescence measurements. The results reported here confirm that micro-ATR infrared spectroscopy can be usefully employed for a non- or minimally invasive detailed characterization of supports for enzyme immobilization.
β -D-Galactosidase (E 3.2.1.23) from Aspergillus oryzae was immobilized onto Teflon membranes grafted using γ- irradiation technique. Various grafted copolymers with varying hydrophilic moieties were prepared using simultaneous co-polymerization to study effect of the resultant microenvironment systems wherefrom type and content of these hydrophilic moieties on the activity of catalytic membranes under both of isothermal and non-isothermal conditions. Diethylene glycol dimethacrylate (DEGDMA), as a hydrophobic monomer was co-polymerized with each of the three hydrophilic monomers; methacrylic acid (MAA), acrylamide (AAM) and 2-hydroxyethyl methacrylate (HEMA). It was found that both of grafting percentage and activity of the catalytic membranes were greatly affected by the type and content of the hydrophilic components in the graft co-polymers. Since, the incorporation of the hydrophilic components in the graft co-polymers exhibited a positive effect on the activity of the catalytic hydrophobic membranes under either of isothermal or non-isothermal conditions. The increase extent in the catalytic activity of Teflon membranes grafted with hydrophobic- hydrophilic co-polymers was ranged from 18 - 27% comparing with the catalytic activity of Teflon membrane grafted with poly-DEGDMA under isothermal conditions. Whereas, these increase extent was ranged from 127 - 188% under non-isothermal conditions. © Society for Biomaterials and Artificial Organs (India), 20090503-42
Bisphenol A (BPA) is an endocrine disruptor (ED) that is abundant in the environment because of its extensive use in human-manufactured products. In this study, the BPA concentration was measured in the muscle and liver of five edible fish, characterized by different habitat and habits, caught in two different sites of the Tyrrhenian Sea (Italy). Our results show that: (i) fish livers are about 2.5 times more polluted than muscle; (ii) fish caught in the Gulf of Naples are more polluted than those from the Latium coasts, ranging from 1.2-fold more for White Bream to 6.6-fold for Grey Mullet; and (iii) the percentages of fish found to be BPA-polluted in the Gulf of Naples ranged from 73% (for Bass) to 90% (for Mullet), while the Latium fish range from 60% (for Bass) to 90% (for Mullet). These data indicate that consumers of fish caught in the Gulf of Naples are at a greater risk for BPA-induced endocrine pathologies compared to those who consume fish caught along the Latium coasts.
In view of the heath problems induced by the presence into the environment of endocrine disruptors, laccase from Trametes versicolor was covalently immobilized on a chemically modified polypropylene membrane in order to remove phenol and its derivatives from polluted waters. Using phenol as substrate model the optimal immobilization conditions were determined. The immobilized laccase exhibited maximal enzyme activity at pH 5.5 and optimal temperature at 55°C. These operative parameters have been compared with those obtained with the soluble laccase in order to ascertain the immobilization effect.When employed in a bioreactor operating under isothermal conditions the immobilized laccase was able to oxidize a wide range of phenolic substrates. In particular it was found that some phenol derivatives (2-CP, 3-CP, 4-CP, NP and chlorophene) were oxidized at a similar rate than phenol, other derivatives (paracetamol, 3-MP and chloroxyphenol) at a smaller rate, while others (2,4-DCP and BPA) at higher rate.When the catalytic membrane was employed in a non-isothermal reactor the reaction rate increased with the increase of the applied temperature difference. Practically the increase of the laccase oxidative power under the non-isothermal conditions followed the same sequence observed under isothermal conditions. Interesting enough, the percentage increase of enzyme reaction rate under non-isothermal conditions resulted higher in the cases in which the isothermal reaction rate was smaller.When the reduction of the production times by the presence of a temperature gradient is considered, the measured values strongly candidate the technology of non-isothermal bioreactors as a useful tool in processes of detoxification of waste waters polluted by endocrine disruptors of phenolic origin.
The investigation of materials suitable for enzyme immobilization in biosensing applications has a widespread interest. There are many studies on physico-chemical properties of these materials at macroscopic level but few studies have been devoted to examine and correlate these properties at microscopic level. FT-IR spectroscopy with Micro-Attenuated Total Reflection (Micro-ATR) approach can be extremely useful for understanding a variety of aspects of materials which can be used for optimising immobilization procedures. Moreover, this experimental approach is particularly simple to use (no sample preparation is required) and minimally invasive. Using a Perkin Elmer Spectrum One FT-IR spectrometer equipped with a mercury-cadmium-telluride detector and a micro-ATR element we investigated different materials used for immobilization procedures with various enzymes widely used for biosensing in environmental and clinical applications. In particular, composite membranes constituted by a chemically modified poly-acrylonitrile (PAN) membrane plus layers of tethered chitosan of different molecular weight have been examined. Also silica gel matrices without and with glucose oxidase have been investigated. Spectra have been analysed and the contribution of principal functional groups has been evidenced.
A series of electrospun mats of styrene–maleic anhydride copolymers has been functionalized by modification with two types of spacers – a polymer with a flexible hydrophilic polyether chain (Jeffamine® ED) and a rigid low-molecular-weight spacer (р-phenylenediamine). The successful modification of the microfibrous mats with these bifunctional compounds has been proved by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) analyses. In a further step, acetylcholinesterase (AChE) has been covalently immobilized onto the modified mats using glutaraldehyde as a binding agent. The amount of bound protein and the specific activity of the immobilized AChE have been determined. The highest activity has been displayed by AChE covalently bound to Jeffamine-modified microfibrous mats. Moreover, the immobilized AChE is characterized by enhanced thermal and storage stability as compared to the free enzyme.