RESUMO
Ciguatera poisoning (CP) is a severe seafood-borne disease, caused by the consumption of reef fish contaminated with Caribbean ciguatoxins (C-CTXs) in the Caribbean and tropical Atlantic. However, C-CTXs have not been identified from their presumed algal source, so the relationship to the CTXs in fish causing illness remains unknown. This has hindered the development of detection methods, diagnostics, monitoring programs, and limited fundamental knowledge on the environmental factors that regulate C-CTX production. In this study, in vitro and chemical techniques were applied to unambiguously identify a novel C-CTX analogue, C-CTX5, from Gambierdiscus silvae and Gambierdiscus caribaeus strains from the Caribbean. Metabolism in vitro by fish liver microsomes converted algal C-CTX5 into C-CTX1/2, the dominant CTX in ciguatoxic fish from the Caribbean. Furthermore, C-CTX5 from G. silvae was confirmed to have voltage-gated sodium-channel-specific activity. This finding is crucial for risk assessment, understanding the fate of C-CTXs in food webs, and is a prerequisite for development of effective analytical methods and monitoring programs. The identification of an algal precursor produced by two Gambierdiscus species is a major breakthrough for ciguatera research that will foster major advances in this important seafood safety issue.
Assuntos
Ciguatera , Ciguatoxinas , Dinoflagellida , Animais , Ciguatoxinas/toxicidade , Região do Caribe , PeixesRESUMO
With the expansion of the aquaculture industry in the last two decades, there has been a large increase in the use of plant ingredients in aquafeeds, which has created new challenges in fish growth, health and welfare. Fish muscle growth is an important trait that is strongly affected by diet, but our knowledge on the effect of plant protein-based diets on global gene expression in muscle is still scant. The present study evaluated nutrigenomic effects of the inclusion of proteins from pea, soy and wheat into aquafeeds, compared to a control diet with fishmeal as the main protein source using the zebrafish model by RNA-seq; these results were extended to an important aquaculture species by analyzing selected differentially expressed genes identified in the zebrafish model on on-growing Atlantic salmon fed with equivalent plant protein-based diets. Expression of selected Atlantic salmon paralogues of the zebrafish homologs was analyzed using paralogue-specific qPCR assays. Global gene expression changes in muscle of zebrafish fed with plant-based diets were moderate, with the highest changes observed in the soy diet-fed fish, and no change for the pea diet-fed fish compared to the control diet. Among the differentially expressed genes were mylpfb, hsp90aa1.1, col2a1a, and odc1, which are important in regulating muscle growth, maintaining muscle structure and function, and muscle tissue homeostasis. Furthermore, those genes and their paralogues were differentially expressed in Atlantic salmon fed with the equivalent percentage of soy or wheat protein containing diets. Some of these genes were similarly regulated in both species while others showed species-specific regulation. The present study expands our understanding on the molecular effects of plant ingredients in fish muscle. Ultimately, the knowledge gained would be of importance for the improved formulation of sustainable plant-based diets for the aquaculture industry.
RESUMO
Food allergy affects up to 6% of Europeans. Allergen identification is important for the risk assessment and management of the inadvertent presence of allergens in foods. The VITAL® initiative for voluntary incidental trace allergen labeling suggests protein reference doses, based on clinical reactivity in food challenge studies, at or below which voluntary labelling is unnecessary. Here, we investigated if current analytical methodology could verify the published VITAL® 2.0 doses, that were available during this analysis, in serving sizes between 5 and 500 g. Available data on published and commercial ELISA, PCR and mass spectrometry methods, especially for the detection of peanuts, soy, hazelnut, wheat, cow's milk and hen's egg were reviewed in detail. Limit of detection, quantitative capability, matrix compatibility, and specificity were assessed. Implications by the recently published VITAL® 3.0 doses were also considered. We conclude that available analytical methods are capable of reasonably robust detection of peanut, soy, hazelnut and wheat allergens for levels at or below the VITAL® 2.0 and also 3.0 doses, with some methods even capable of achieving this in a large 500 g serving size. Cow's milk and hen's egg are more problematic, largely due to matrix/processing incompatibility. An unmet need remains for harmonized reporting units, available reference materials, and method ring-trials to enable validation and the provision of comparable measurement results.
Assuntos
Alérgenos/análise , Análise de Alimentos/normas , Hipersensibilidade Alimentar/imunologia , Alimentos/efeitos adversos , Animais , Ensaio de Imunoadsorção Enzimática , Europa (Continente) , Análise de Alimentos/métodos , Humanos , Espectrometria de MassasRESUMO
Epigenetic modifications, such as DNA methylation, can be regulated by nutrition and dietary factors. There has been a large increase in the use of sustainable plant-based protein sources in fish feed due to limitations of fishmeal resources, which are needed to sustain a rapidly growing aquaculture industry. With this major transition from marine ingredients to plant-based diets, fish are abruptly introduced to changes in dietary composition and exposed to a variety of phytochemicals, some of which known to cause epigenetic changes in mammals. However, the effect of plant ingredients on the epigenome of fish is barely understood. In the present study, the nutriepigenomic effects of the addition of pea, soy, and wheat gluten protein concentrate to aquafeeds were investigated using zebrafish as a model. A genome-wide analysis of DNA methylation patterns was performed by reduced representation bisulphite sequencing to examine global epigenetic alterations in the mid intestine after a 42-day feeding trial. We found that inclusion of 30% of wheat gluten, pea and soy protein concentrate in the diet induced epigenetic changes in the mid intestine of zebrafish. A large number of genes and intergenic regions were differentially methylated with plant-based diets. The genes concerned were related to immunity, NF-κB system, ubiquitin-proteasome pathway, MAPK pathway, and the antioxidant defence system. Epigenetic regulation of several biological processes, including neurogenesis, cell adhesion, response to stress and immunity was also observed. Ultimately, the observed epigenetic changes may enable zebrafish to rapidly regulate inflammation and maintain intestinal homoeostasis when fed plant protein-based diets.
Assuntos
Epigênese Genética , Mucosa Intestinal/metabolismo , Proteínas de Vegetais Comestíveis/metabolismo , Animais , Metilação de DNA , Sistema de Sinalização das MAP Quinases , NF-kappa B/genética , NF-kappa B/metabolismo , Ubiquitinação , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
The mycotoxin enniatin B1 (ENN B1) is widely present in grain-based feed and food products. In the present study, we have investigated how this lipophilic and ionophoric molecule can affect the lysosomal stability and chaperone-mediated autophagy (CMA) in wild-type (WT) and in lysosome-associated membrane proteins (LAMP)-1/2 double-deficient (DD) mouse embryonic fibroblasts (MEF). The cell viability and lysosomal pH were assessed using the Neutral Red (NR) cytotoxicity assay and the LysoSensor® Yellow/Blue DND-160, respectively. Changes in the expression of the CMA-related components LAMP-2 and the chaperones heat shock cognate (hsc) 70 and heat shock protein (hsp) 90 were determined in cytosolic extracts by immunoblotting. In the NR assay, LAMP-1/2 DD MEF cells were significantly less sensitive to ENN B1 than WT MEF cells after 24 h exposure to ENN B1 at levels of 2.5-10 µmol/L. Exposure to ENN B1 at concentrations below the half maximal effective concentration (EC50) (1.5-1.7 µmol/L) increased the lysosomal pH in WT MEF, but not in LAMP-1/2 DD cells, suggesting that lysosomal LAMP-2 is an early target of ENN B1-induced lysosomal alkalization and cytotoxicity in MEF cells. Additionally, cytosolic hsp90 and LAMP-2 levels slightly increased after exposure for 4 h, indicating lysosomal membrane permeabilization (LMP). In summary, it appeared that ENN B1 can destabilize the LAMP-2 complex in the lysosomal membrane at concentrations close to the EC50, resulting in the alkalinization of lysosomes, partial LMP, and thereby leakage of CMA-associated components into the cytosol.
Assuntos
Depsipeptídeos/toxicidade , Membranas Intracelulares/efeitos dos fármacos , Lisossomos/patologia , Micotoxinas/toxicidade , Permeabilidade/efeitos dos fármacos , Animais , Autofagia Mediada por Chaperonas/efeitos dos fármacos , Fibroblastos , Deleção de Genes , Proteínas de Choque Térmico HSC70/efeitos dos fármacos , Proteínas de Choque Térmico HSC70/metabolismo , Proteínas de Choque Térmico HSP90/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/metabolismo , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Proteína 2 de Membrana Associada ao Lisossomo/efeitos dos fármacos , Proteína 2 de Membrana Associada ao Lisossomo/genética , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Camundongos , Chaperonas Moleculares/efeitos dos fármacos , Chaperonas Moleculares/metabolismoRESUMO
Enniatins (ENNs) are fungal secondary metabolites that frequently occur in grain in temperate climates. Their toxic potency is connected to their ionophoric character and lipophilicity. The biotransformation of ENNs predominantly takes place via cytochrome P450 3A (CYP 3A)-dependent oxidation reactions. Possible interaction with ENNs is relevant since CYP3A4 is the main metabolic enzyme for numerous drugs and contaminants. In the present study, we have determined the kinetic characteristics and inhibitory potential of ENNB1 in human liver microsomes (HLM) and CYP3A4-containing nanodiscs (ND). We showed in both in vitro systems that ENNB1 is mainly metabolised by CYP3A4, producing at least eleven metabolites. Moreover, ENNB1 significantly decreased the hydroxylation rates of the typical CYP3A4-substrate midazolam (MDZ). Deoxynivalenol (DON), which is the most prevalent mycotoxin in grain and usually co-occurrs with the ENNs, was not metabolised by CYP3A4 or binding to its active site. Nevertheless, DON affected the efficiency of this biotransformation pathway both in HLM and ND. The metabolite formation rates of ENNB1 and the frequently used drugs progesterone (PGS) and atorvastatin (ARVS) lactone were noticeably reduced, which indicated a certain affinity of DON to the enzyme with subsequent conformational changes. Our results emphasise the importance of drug-drug interaction studies, also with regard to natural toxins.
RESUMO
The mycotoxin deoxynivalenol (DON) has a high global prevalence in grain-based products. Biomarkers of exposure are detectable in most humans and farm animals. Considering the acute emetic and chronic anorexigenic toxicity of DON, maximum levels for food and feed have been implemented by food authorities. The tolerable daily intake (TDI) is 1 µg/kg body weight (bw)/day for the sum of DON and its main derivatives, which was based on the no-observed adverse-effect level (NOAEL) of 100 µg DON/kg bw/day for anorexic effects in rodents. Chronic exposure to a low-DON dose can, however, also cause inflammation and imbalanced neurotransmitter levels. In the present study, we therefore investigated the impact of a 2-week exposure at the NOAEL in mice by performing behavioural experiments, monitoring brain activation by c-Fos expression, and analysing changes in the metabolomes of brain and serum. We found that DON affected neuronal activity and innate behaviour in both male and female mice. Metabolite profiles were differentiable between control and treated mice. The behavioural changes evidenced at NOAEL reduce the safety margin to the established TDI and may be indicative of a risk for human health.
Assuntos
Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Exposição Dietética/efeitos adversos , Fígado/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Encéfalo/metabolismo , Exposição Dietética/análise , Feminino , Contaminação de Alimentos/análise , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Comportamento de Nidação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Tricotecenos/farmacocinéticaRESUMO
The tremorgenic mycotoxin Thomitrem A is a secondary metabolite produced mainly by the fungus Penicillium crustosum that is frequently found on spoiled stored food and feed. Typical signs of intoxication observed in dogs after the consumption of food waste are emesis, tremors, seizures progressing to ataxia and lack of coordinated movements. How uptake of Thomitrem A relates to exposure is unknown so far since data on biotransformation and toxicokinetics are missing. In this study the toxin was therefore metabolised in an exploratory in vitro experiment by rat hepatocytes, and substrate depletion as well as the formation of hepatic metabolites were investigated. Seven metabolites were characterised by their retention times and fragmentation patterns in LC-MS/MS analysis. They were found to be products of oxidation and dehydration processes and occurred at different incubation time points, showing different signal abundance-time curve profiles. Toxicokinetic parameters were derived from the Thomitrem A depletion curve applying principles of in vitro-to-in vivo extrapolation (IVIVE). The predicted medium maximum bioavailability in rats could be of importance for the assessment of exposure in cases of intoxication if it was confirmed in vivo and in other species.
Assuntos
Alcaloides/farmacocinética , Hepatócitos/metabolismo , Indóis/farmacocinética , Animais , Biotransformação , Células Cultivadas , Cromatografia Líquida , Ratos , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Epitope mapping of an allergen is generally done by IgE-binding assays with short synthetic peptides, but this provides little information about which domains are responsible for IgE receptor crosslinking on effector cells. Our aim was to map the immunodominant regions of shrimp tropomyosin by both IgE-binding and IgE-receptor crosslinking studies. METHODS: Five overlapping fragments covering Pandalus borealis tropomyosin were cloned, expressed in Escherichia coli and characterized by circular dichroism spectroscopy, native PAGE and bis(sulfosuccinimidyl) suberate-crosslinking. IgE binding was detected by Western blot, indirect ELISA and inhibition ELISA, and IgE receptor crosslinking was investigated by basophil activation test and skin prick test with Norwegian shrimp allergic adults. RESULTS: The N- and C-terminal fragments of tropomyosin showed the highest amount of secondary structure. Western blot studies showed preferential binding to the terminal fragments, while indirect and inhibition ELISA studies showed binding to all fragments, but with individual variations. Basophil CD63 expression was upregulated by all fragments at high concentrations (1 µg/ml) and showed individual variations comparable to ELISA results. A mixture of the fragments with equal molar ratios induced comparably strong CD63 activation as for tropomyosin. Skin prick test studies showed positive responses to the terminal and middle fragments and increased responses to the fragment mixture compared to whole tropomyosin. CONCLUSIONS: The terminal and middle fragments of tropomyosin had the highest IgE reactivity, but overall no clear immunodominant region was observed in this study. These results correlated well with previous studies with short peptides. Dividing shrimp tropomyosin into five fragments did not reduce the allergenicity of the protein.
Assuntos
Alérgenos/genética , Proteínas de Artrópodes/genética , Epitopos Imunodominantes/genética , Imunoglobulina E/metabolismo , Receptores de IgE/metabolismo , Adulto , Alérgenos/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/imunologia , Mapeamento Cromossômico , Dicroísmo Circular , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Pandalidae/genética , Pandalidae/imunologia , Ligação Proteica , Alinhamento de Sequência , Tetraspanina 30/imunologiaRESUMO
Several cases of neurological disease in dogs after poisoning by food- and feed-borne Penicillium toxins in Norway during the last years have uncovered a lack of knowledge regarding the toxicity and mechanism of action of neuroactive mycotoxins. In the present study, the lowest tremor-inducing dose after single oral administration of penitrem A to mice was 0.50 mg/kg bw. The estimated half maximal effective dose (ED(50)) in respect to the visual tremor scale was 2.74 mg/kg bw. Mice receiving the maximum penitrem A dose (8 mg/kg bw) suffered severe spontaneous tremors and even convulsions. Thomitrem A and E are penitrem analogues lacking the C-16-C-18 ether linkage and possessing an olefin at C-18-C-19. Compared with penitrem A, the lowest tremor-inducing dose of thomitrem A was 16-times higher (8 mg/kg bw) and thomitrem E was found to be non-tremorgenic at the highest dose tested (16 mg/kg bw). During a recovery phase of two weeks post administration animals appeared restored and no changes in feeding and other biological processes were observed. An initial dose-related weight reduction was observed 2 days after penitrem A administration. Penitrem A was absorbed and distributed to gastrointestinal tract, liver, kidneys and brain in the mice. Elimination of penitrem A appeared to be mainly hepatic and the highest concentration levels were found 1 h post administration for all investigated organs. The relationship between liver and gastrointestinal tract concentration levels showed time-dependent linear correlation and a doubling within 1.5 h.
Assuntos
Indóis/toxicidade , Micotoxinas/toxicidade , Penicillium/metabolismo , Tremor/induzido quimicamente , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão , Indóis/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Micotoxinas/administração & dosagem , Espectrometria de Massas em TandemRESUMO
The Norwegian Food Allergy Register was established at the Norwegian Institute of Public Health in 2000. The purpose of the register is to gain information about severe allergic reactions to food in Norway and to survey food products in relation to allergen labelling and contamination. Cases are reported on a voluntary basis by first line doctors, and submitted together with a serum sample for specific IgE analysis. The register has received a total of 877 reports from 1 July, 2000 to 31 December, 2010. Two age groups, small children and young adults are over-represented, and the overall gender distribution is 40:60 males-females. The legumes lupine and fenugreek have been identified as two "new" allergens in processed foods and cases of contamination and faults in production of processed foods have been revealed. The highest frequency of food specific IgE is to hazelnuts and peanuts, with a marked increase in reactions to hazelnuts during the last three years. The Food Allergy Register has improved our knowledge about causes and severity of food allergic reactions in Norway. The results show the usefulness of population based national food allergy registers in providing information for health authorities and to secure safe food for individuals with food allergies.
Assuntos
Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/etiologia , Sistema de Registros , Adolescente , Adulto , Distribuição por Idade , Idoso , Criança , Pré-Escolar , Feminino , Hipersensibilidade Alimentar/diagnóstico , Humanos , Imunoglobulina E/sangue , Lactente , Recém-Nascido , Lupinus/imunologia , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Distribuição por Sexo , Trigonella/imunologiaRESUMO
Enniatins are cyclic hexapeptidic mycotoxins produced by fungi growing on field grains, especially in wet climates. They show considerable resistance to food and feed processing technologies and might cause intoxication of humans and animals. Enniatins are also under exploration as anticancer drugs. The observed difference of in vitro and in vivo toxicities suggests low absorption or fast elimination of the enniatins after oral uptake. In the study presented here, in vitro metabolism studies of enniatin B were performed using rat, dog, and human liver microsomes under conditions of linear kinetics to estimate the respective elimination rates. Furthermore, cytochrome P450 reaction phenotyping with chemical inhibitors selective for human enzymes was carried out. Twelve metabolites were separated and characterized by multiple high-performance liquid chromatographic/mass spectrometric analyses as products of oxidation and demethylation reactions. Biotransformation rates and metabolite patterns varied considerably in the three species. The intrinsic clearances determined in assays with rat, dog, and human liver microsomes were 1.16, 8.23, and 1.13 l/(h · kg), respectively. The predicted enniatin B in vivo blood clearances were 1.57 l/(h · kg) in rats, 1.67 l/(h · kg) in dogs, and 0.63 l/(h · kg) in humans. CYP3A4 was important for enniatin B metabolism in human microsomes as shown by 80% inhibition and impaired metabolite formation in the presence of troleandomycin. CYP1A2 and CYP2C19 were additionally involved. Preliminary results showed that CYP3A and CYP1A might also be relevant in rats and dogs. The extensive hepatic metabolism could explain the reduced in vivo potential of enniatin B.
Assuntos
Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Depsipeptídeos/metabolismo , Microssomos Hepáticos/metabolismo , Micotoxinas/metabolismo , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão/métodos , Cães , Humanos , Masculino , Espectrometria de Massas/métodos , Microssomos Hepáticos/enzimologia , Ratos , Ratos WistarRESUMO
Celery is acknowledged as a major food allergen in Europe, and mandatory labeling for preprocessed foods has been implemented. However, no methods for the specific detection of celery protein in foods have been published. In the present study, a sandwich celery ELISA using polyclonal anticelery antibodies for capture and detection was developed and validated. The method has an LOD of 0.5 mg/kg in buffer; however, it is applicable only for the screening of food products because of extensive cross-reactivity with potato and carrot proteins. Using nanoLC-ion-trap MS/MS, a number of proteins in the three vegetable species were identified as candidates for causing cross-reactions due to amino acid sequence homologies. Among others, a novel patatin (Sola t 1)-like protein was detected in celery and a flavin adenine dinucleotide binding domain-containing protein (Api g 5)-like protein was identified in carrot. The utility of triple-quadrupole MS/MS for specific and quantitative analysis of celery, potato, and carrot allergens was evaluated using whole protein extracts. Several unique precursor ion-to-product ion transitions were determined for each species, suggesting the feasibility of developing an MS-based screening method to specifically detect celery allergens in foods.
Assuntos
Alérgenos/imunologia , Apium , Reações Cruzadas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Hipersensibilidade Alimentar/imunologia , Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Alérgenos/química , Sequência de Aminoácidos , Antígenos de Plantas , Soluções Tampão , Hidrolases de Éster Carboxílico/química , Daucus carota , Humanos , Dados de Sequência Molecular , Proteínas de Plantas/química , Reprodutibilidade dos Testes , Homologia de Sequência de Aminoácidos , VerdurasRESUMO
Penitrem A is a potent neurotoxin produced by several species in the genus Penicillium, which primarily affects the central nervous system. The toxin has several effects on neurotransmitter release, both at the central and peripheral level, as well as on ion channels. We have evaluated the hepatic metabolism of penitrem A by rat hepatocytes and rat-liver microsomes in vitro. In addition, we have conducted an in vivo study in mice and determined metabolites in several organs. According to our results, penitrem A is extensively metabolized in the liver to at least five metabolites more hydrophilic than the parent compound.
Assuntos
Micotoxinas/metabolismo , Neurotoxinas/metabolismo , Penicillium/metabolismo , Animais , Cromatografia Líquida de Alta Pressão/métodos , Hepatócitos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Masculino , Espectrometria de Massas/métodos , Camundongos , Camundongos Endogâmicos C57BL , Microssomos Hepáticos/metabolismo , Ratos , Ratos WistarRESUMO
BACKGROUND: The increasing number of applications of sweet lupins in food is paralleled by an increase in immunoglobulin E (IgE)-mediated allergic reactions to lupin proteins. In particular, lupin allergy seems to appear in patients with an existing peanut allergy. In the present study, IgE-binding studies towards fractionated lupin seed proteins, and peanut and almond proteins were performed using sera from patients with confirmed lupin allergy. METHODS: Immunoblotting and indirect ELISA were performed to investigate IgE binding to protein extracts. ELISA inhibition experiments were performed to investigate the presence of cross-reactive allergens in the protein extracts. RESULTS: Immunoblotting and ELISA experiments demonstrated IgE binding to all lupin conglutins (alpha, beta, gamma and delta) as well as to peanut and almond proteins, with a unique IgE-binding profile for each patient. High IgE binding to alpha-conglutin was observed and IgE from the majority of patients similarly recognized two proteins within the alpha-conglutin-containing fraction, 40 and 43 kDa in size. Inhibition ELISA experiments showed that preincubation of sera with lupin conglutins, peanut and almond resulted in decreased IgE binding to lupin flour. CONCLUSIONS: Overall, these results indicate that alpha-, beta-, gamma- and delta-conglutins are candidate allergens in lupin and suggest a particularly strong allergenicity of alpha-conglutins. Furthermore, the results indicate the presence of cross-reactive allergens in lupin, peanut and almond.
Assuntos
Arachis/imunologia , Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/imunologia , Lupinus/imunologia , Proteínas de Plantas/imunologia , Prunus/imunologia , Adolescente , Criança , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Hipersensibilidade Alimentar/sangue , Humanos , Immunoblotting , Imunoglobulina E/sangue , Masculino , Proteínas de Armazenamento de SementesRESUMO
Allergy to fish represents one of the most prevalent causes for severe food-allergic reactions. Therefore, food authorities in different countries have implemented mandatory labeling of fish in pre-packed foods. Detection of fish proteins in food has previously been based on the use of patient serum. In the present study, a novel sandwich enzyme-linked immunosorbent assay (ELISA) for the quantitation of fish in food matrixes has been developed and validated, using a polyclonal rabbit anti-cod parvalbumin antibody for capture and a biotinylated conjugate of the same antibody for detection. By employing the ubiquitous muscle protein parvalbumin as target the method succeeds to detect a variety of fish. However, the ELISA is specific for fish and does not cross-react with other species. Recoveries ranged from 68-138% in typical food matrixes, while the intra- and inter-assay precisions were <12% and <19%, respectively. The sensitivity of the cod parvalbumin ELISA with a limit of detection of 0.01 mg parvalbumin/kg food, about 5 mg fish/kg food, seems sufficient to detect fish protein traces in foods at levels low enough to minimize the risk for fish allergic consumers.
Assuntos
Alérgenos/análise , Anticorpos , Ensaio de Imunoadsorção Enzimática , Proteínas de Peixes/análise , Análise de Alimentos/métodos , Contaminação de Alimentos , Parvalbuminas/análise , Alérgenos/imunologia , Alérgenos/isolamento & purificação , Animais , Especificidade de Anticorpos , Biotinilação , Calibragem , Ensaio de Imunoadsorção Enzimática/normas , Proteínas de Peixes/imunologia , Proteínas de Peixes/isolamento & purificação , Análise de Alimentos/normas , Hipersensibilidade Alimentar/prevenção & controle , Gadus morhua , Humanos , Parvalbuminas/imunologia , Parvalbuminas/isolamento & purificação , Reprodutibilidade dos Testes , Especificidade da EspécieRESUMO
The ubiquitous muscle protein tropomyosin has been identified as the major shrimp allergen and is suggested to be a cross-reacting allergen. Previously, only a few methods for the detection of tropomyosin in food have been published. A quantitative sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of tropomyosin from crustaceans in foods has been developed and validated. A polyclonal rabbit antitropomyosin capture antibody and the biotinylated conjugate of the same antibody for detection were the basis for the ELISA, which was specific for crustaceans. The ELISA was able to quantitate tropomyosin in various food matrixes, had a detection limit of 1 microg/g, and cross-reacted to some extent with cockroach. Recoveries ranged from 63 to 120%, and the intra and interassay coefficients of variation were <6 and <14%, respectively.
Assuntos
Alérgenos/análise , Crustáceos/química , Ensaio de Imunoadsorção Enzimática/métodos , Frutos do Mar/análise , Tropomiosina/análise , Alérgenos/química , Animais , Anticorpos , Biotinilação , Coelhos , Sensibilidade e Especificidade , Alinhamento de Sequência , Tropomiosina/química , Tropomiosina/imunologiaRESUMO
Hen's egg white protein is a major cause of food allergy, and a considerable number of countries have introduced labeling directions for processed food products. To control compliance with these regulations, analytical assays for the detection of egg in manufactured foods have been developed. In this study, we have tested the performance of 3 commercially available kits for quantitative egg analysis using 6 model heat-processed foods. The 3 assays worked well under standard conditions with soluble egg white proteins, but only the kit using a denaturing-reducing extraction buffer detected egg in complex heat-treated food matrixes. The differently extracted food samples were further used to evaluate the stability and allergenicity of the egg white allergens ovalbumin, ovomucoid, ovotransferrin, and lysozyme with polyclonal anti-egg antibodies and sera of 6 patients with egg allergy. It could be shown that differences in egg protein extractability have a significant impact on the interpretation of study results.
Assuntos
Conalbumina/química , Proteínas do Ovo/análise , Muramidase/química , Ovalbumina/química , Ovomucina/química , Animais , Calibragem , Galinhas , Proteínas do Ovo/química , Clara de Ovo , Ensaio de Imunoadsorção Enzimática , Conservação de Alimentos , Humanos , Imunoensaio/métodos , Reprodutibilidade dos Testes , SoloRESUMO
BACKGROUND: The ingestion of dietary products containing sweet lupin (such as Lupinus albus or Lupinus angustifolius) has been reported to cause IgE-mediated allergic reactions. Recent studies have indicated lupin globulins as important IgE binding proteins. The aim of the present study was to generate and characterize monoclonal antibodies (mAbs) against lupin seed proteins. METHODS: Mice were immunized with a protein isolate from L. albus and mAbs were obtained by hybridoma techniques. Albumins and globulins were extracted, and the globulin fraction was separated further into conglutins by anion exchange chromatography. Specificities, binding patterns and applications of the mAbs were investigated by immunochemical methods. RESULTS: Five mAbs were produced: Lu11 (an IgG2b antibody), Lu8, Lu18, Lu34 and Lu35 (all IgM antibodies). The mAbs reacted strongly with protein isolates from both L. albus and L. angustifolius. All mAbs are directed towards the lupin globulin fraction; Lu11 and Lu18 recognize alpha-conglutin, while Lu8, Lu34 and Lu35 recognize beta-conglutin. In addition, Lu11 inhibited the binding of IgE from patients with positive skin prick tests to lupin proteins in a competitive ELISA by approximately 30%. Furthermore, preliminary results show that Lu11 can be used to develop a sensitive method for the detection of alpha-conglutin in foods. CONCLUSIONS: Lupin globulins are immunogenic and alpha-conglutin is a potential allergen. This is the first study describing mAbs against the candidate lupin allergens, emphasizing the importance of additional studies on conglutins in lupin allergy.
Assuntos
Anticorpos Monoclonais/imunologia , Proteínas de Plantas/imunologia , Animais , Anticorpos Monoclonais/biossíntese , Especificidade de Anticorpos , Ensaio de Imunoadsorção Enzimática , Feminino , Imunização , Imunoglobulina E/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Armazenamento de SementesRESUMO
The use of lupine in foods has increased considerably during the past decade, reflected by a corresponding increase in reported lupine-induced allergic incidents. Lupine allergy may arise either by primary sensitization or by clinical cross-reactivity in peanut-allergic persons. Detection of lupine proteins in food has previously been based on the use of patient serum. A novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of lupine in processed foods was developed, using a polyclonal rabbit antilupine capture antibody and a biotinylated conjugate of the same antibody for detection. The antibody was highly specific for lupine, apart from minor cross-reactivities to other legumes. The assay had a detection limit of 1 mug/g and was successfully used to quantify lupine protein in various food matrixes. Recoveries ranged from 60 to 116%, while the intra-and interassay coefficients of variation were <6% and <21%, respectively.