RESUMO
Food allergens have a notable potential to induce various health concerns in susceptible individuals. The majority of allergenic foods are usually subjected to thermal processing prior to their consumption. However, during thermal processing and long storage of foods, Maillard reaction (MR) often takes place. The MR is a non-enzymatic glycation reaction between the carbonyl group of reducing sugars and compounds having free amino groups. MR may sometimes be beneficial by damaging epitope of allergens and reducing allergenic potential, while exacerbation in allergic reactions may also occur due to changes in the motifs of epitopes or neoallergen generation. Apart from these modulations, non-enzymatic glycation can also modify the food protein(s) with various type of advance glycation end products (AGEs) such as Nϵ-(carboxymethyl-)lysine (CML), pentosidine, pyrraline, and methylglyoxal-H1 derived from MR. These Maillard products may act as immunogen by inducing the activation and proliferation of various immune cells. Literature is available to understand pathogenesis of glycation in the context of various diseases but there is hardly any review that can provide a thorough insight on the impact of glycation in food allergy. Therefore, present review explores the pathogenesis with special reference to food allergy caused by non-enzymatic glycation as well as AGEs.
Assuntos
Imunidade Adaptativa , Antígenos/efeitos adversos , Proteínas Alimentares/efeitos adversos , Hipersensibilidade Alimentar/etiologia , Produtos Finais de Glicação Avançada/efeitos adversos , Imunidade Inata , Modelos Imunológicos , Antígenos/química , Antígenos/metabolismo , Proteínas Alimentares/química , Proteínas Alimentares/metabolismo , Epitopos , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/metabolismo , Hipersensibilidade Alimentar/patologia , Produtos Finais de Glicação Avançada/química , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Sistema Imunitário/patologia , Fenômenos Imunogenéticos , Lectinas Tipo C/agonistas , Lectinas Tipo C/metabolismo , Reação de Maillard , Receptor de Manose , Lectinas de Ligação a Manose/agonistas , Lectinas de Ligação a Manose/metabolismo , Receptor para Produtos Finais de Glicação Avançada/agonistas , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Receptores de Superfície Celular/agonistas , Receptores de Superfície Celular/metabolismo , Receptores Depuradores/agonistas , Receptores Depuradores/metabolismo , Transdução de SinaisRESUMO
Among food contaminants, mycotoxins are toxic to both human and animal health. Our prior studies suggest that Deoxynivalenol (DON), a mycotoxin, behaves as a tumor promoter by inducing edema, hyperplasia, ODC activity and activation of MAPK's in mouse skin. In this study, topical application of DON, 336 and 672 nmol significantly enhanced ROS levels, DNA damage and apoptosis with concomitant downregulation of Ki-67, cyclin D, cyclin E, cyclin A and cyclin-dependent kinases (CDK4 and CDK2) thereby resulting in tumor initiation in mouse skin. Further, the elucidation of molecular mechanisms of tumor initiation by DON (0.42-3.37 nmol/ml) in HaCaT keratinocytes, revealed (i) enhanced ROS generation with cell cycle phase arrest in G0/G1 phase, (ii) increase in levels of 8-OxoG (6-24 hr) and γH2AX protein, (iii) significant enhancement in oxidative stress marker enzymes LPO, GSH, GR with concomitant decrease in antioxidant enzymes catalase, GPx, GST, SOD and mitochondrial membrane potential after DON (1.68 nmol) treatment, (iv) suppression of Nrf2 translocation to nucleus, enhanced phosphorylation with subsequent activation ERK1/2, p38 and JNK MAPK's following DON (1.68 nmol) treatment, (v) overexpression of c-jun, c-fos proteins, upregulation of Bax along with downregulation of Bcl-2 proteins, (vi) increase in cytochrome-c, caspase-9, caspase-3 and poly ADP ribose polymerase levels leads to apoptosis. Pretreatment of superoxide dismutase, mannitol and ethanol to HaCaT cells resulted in significant reduction in ROS levels and apoptosis indicating the role of superoxide and hydroxyl radicals in DON induced apoptosis as an early event and skin tumor initiation as a late event.
Assuntos
Carcinógenos/toxicidade , Contaminação de Alimentos , Queratinócitos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Tricotecenos/toxicidade , Animais , Apoptose , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Dano ao DNA , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Queratinócitos/patologia , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Cutâneas/metabolismoRESUMO
Zinc oxide nanoparticles (ZNPs) have been used in dietary supplements and may cause an immunomodulatory effect. The present study investigated the effect of ZNPs on antigen-specific immune responses in mice sensitized with the T-cell-dependent antigen ovalbumin (OVA). BALB/c mice were intraperitoneally administered ZNPs (0.25, 0.5, 1 and 3mg) once, in combination with OVA, and the serum antibodies, splenocyte reactivity and activation of antigen-presenting cells were examined. The serum levels of OVA-specific IgG1 and IgE were found significantly enhanced by treatment with ZNPs over control. An increased level of IL-2, IL-4, IL-6, IL-17 and decreased level of IL-10 and TNF-α in splenocytes administered with ZNPs were observed in comparison with control. The ZNPs and OVA-stimulated T lymphocytes showed enhanced proliferation compared with control. Macrophages and B cells showed high expression of MHC class II, whereas higher expression of CD11b in macrophages of the ZNPs and ZNPs/OVA treated groups was observed. The lungs and spleen had increased eosinophils and mast cell numbers. Also, myeloperoxidase activity in lungs was found to be increased by 2.5-fold in the case of ZNPs and 3.75-fold increase in ZNPs/OVA, whereas in intestine, there was significant increase in both the groups. Increased expression of the genes for GATA-3, SOCS-3, TLR-4, IL-13 and IL-5 in the intestine was observed. Collectively, these data indicate that systemic exposure to a single administration of ZNPs could enhance subsequent antigen-specific immune reactions, including the serum production of antigen-specific antibodies, and the functionality of T cells.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Linfócitos B/imunologia , Citocinas/biossíntese , Imunoglobulina E/biossíntese , Imunoglobulina G/biossíntese , Macrófagos/imunologia , Nanopartículas Metálicas/administração & dosagem , Células Th2/imunologia , Animais , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Citocinas/sangue , Citocinas/genética , Suplementos Nutricionais/efeitos adversos , Feminino , Fator de Transcrição GATA3/genética , Fator de Transcrição GATA3/metabolismo , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/genética , Imunoglobulina G/sangue , Imunoglobulina G/genética , Ativação Linfocitária/efeitos dos fármacos , Nanopartículas Metálicas/efeitos adversos , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Regulação para Cima/efeitos dos fármacos , Óxido de Zinco/químicaRESUMO
Macrophages are among the most sensitive immune cells because of their phagocytic activity and are prone to become dysfunctional or not able to perform properly if nanoparticle load increases. We have previously reported that zinc oxide nanoparticles (ZNPs) induce inflammatory responses in macrophages that contribute to their death. Recognition of ZNPs by pattern recognition receptors such as toll-like receptors (TLRs) might be a factor in the initiation of these responses in macrophages. Therefore, in this study we explored the role played by TLR6 and mitogen-activated protein kinase (MAPKs) pathways in the inflammatory responses of macrophages during ZNPs exposure. ZNPs-activated macrophages showed enhanced expression of activation and maturation markers (CD1d, MHC-II, CD86 and CD71). Among various TLRs screened, TLR6 emerged as the most potent activator for ZNPs-induced inflammatory responses. Downstream signalling proteins myeloid differentiation 88, interleukin-1 receptor associated kinase and tumour necrosis factor receptor-associated factor were also enhanced. On inhibiting MAPKs pathways individually, the inflammatory responses such as interleukin-1ß, interleukin-6, tumour necrosis factor-α, cyclooxygenase-2 and inducible nitric oxide synthase were suppressed. TLR6 silencing significantly inhibited the pro-inflammatory cytokine levels, reactive nitrogen species generation and inducible nitric oxide synthase expression. Also, inhibition of MAPKs in the absence of TLR6 signalling validated the link between TLR6 and MAPKs in ZNPs-induced inflammatory responses. TLR6 was found to be co-localized with autophagosomes. Macrophages lacking TLR6 inhibited the autophagosome marker protein-microtubule-associated protein1 light chain 3-isoform II formation and phagocytosis. These results demonstrate that inflammatory responses caused by ZNPs-activated macrophages strongly depend on TLR6-mediated MAPK signalling.
Assuntos
Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Nanopartículas/química , Receptor 6 Toll-Like/metabolismo , Óxido de Zinco/farmacologia , Animais , Relação Dose-Resposta a Droga , Feminino , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Patulin (PAT), a present day major contaminant of commercial apple and apple products is reported to be carcinogenic, embryotoxic, and immunotoxic. While oral and inhalation are considered to be the most prevalent routes of exposure to this toxin, exposure through skin is now being extensively investigated. Our previous study showed that short-term dermal exposure to PAT resulted in toxicological injury to the skin, while long-term exposure induced skin tumorigenesis. In this study, we explore the mechanism involve in proliferation of mouse keratinocytes by PAT. Our study revealed that PAT rapidly induces phosphorylation of EGFR, activation of the Ras/MAPKs, and Akt pathways. This in-turn leads to the activation of NF-κB/AP-1 transcription factors which then binds to the promoter region of the cell growth regulatory genes Cyclin D1 and COX-2 inducing their expression leading ultimately to PMKs proliferation. Inhibition of EGFR or the Ras/MAPKs, PI3/Akt pathways with different pharmacological inhibitors or knockdown of NF-κB, c-jun, c-fos, Cyclin D1, and COX-2 with siRNA inhibited PAT-induced PMKs proliferation.
Assuntos
Proliferação de Células/genética , Ciclina D1/genética , Ciclo-Oxigenase 2/genética , Receptores ErbB/genética , Queratinócitos/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Proto-Oncogênicas c-akt/genética , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Queratinócitos/efeitos dos fármacos , Camundongos , NF-kappa B/genética , Patulina/efeitos adversos , Fosfatidilinositol 3-Quinases/genética , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-jun/genética , Transdução de Sinais/genética , Fator de Transcrição AP-1/genética , Proteínas ras/genéticaRESUMO
Several toxicological manifestations of deoxynivalenol (DON), a mycotoxin, are well documented; however, dermal toxicity is not yet explored. The effect of topical application of DON to mice was studied using markers of skin proliferation, inflammation and tumor promotion. Single topical application of DON (84-672nmol/mouse) significantly enhanced dermal hyperplasia and skin edema. DON (336 and 672nmol) caused significant enhancement in [(3)H]-thymidine uptake in DNA along with increased myeloperoxidase and ornithine decarboxylase activities, suggesting tissue inflammation and cell proliferation. Furthermore, DON (168nmol) caused enhanced expression of RAS, and phosphorylation of PI3K/Akt, ERK, JNK and p38 MAPKs. DON exposure also showed activation of transcription factors, c-fos, c-jun and NF-κB along with phosphorylation of IkBα. Enhanced phosphorylation of NF-κB by DON caused over expression of target proteins, COX-2, cyclin D1 and iNOS in skin. Though a single topical application of DMBA followed by twice weekly application of DON (84 and 168nmol) showed no tumorigenesis after 24weeks, however, histopathological studies suggested hyperplasia of the epidermis and hypertrophy of hair follicles. Interestingly, intestine was also found to be affected as enlarged Peyer's patches were observed, suggesting inflammatory effects which were supported by elevation of inflammatory cytokines after 24weeks of topical application of DON. These results suggest that DON induced cell proliferation in mouse skin is through the activation of MAPK signaling pathway involving transcription factors NFκB and AP-1, further leading to transcriptional activation of downstream target proteins c-fos, c-jun, cyclin D1, iNOS and COX-2 which might be responsible for its inflammatory potential.
Assuntos
Proliferação de Células , Dermatite/etiologia , Mediadores da Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pele/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Citocinas/metabolismo , Dermatite/enzimologia , Dermatite/genética , Dermatite/imunologia , Dermatite/patologia , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/enzimologia , Edema/imunologia , Edema/patologia , Ativação Enzimática , Feminino , Regulação da Expressão Gênica , Hiperplasia , Hipertrofia , Camundongos , Ornitina Descarboxilase/metabolismo , Peroxidase/metabolismo , Nódulos Linfáticos Agregados/efeitos dos fármacos , Nódulos Linfáticos Agregados/enzimologia , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/patologia , Fosforilação , Medição de Risco , Pele/enzimologia , Pele/imunologia , Pele/patologia , Fatores de Tempo , Fatores de Transcrição/metabolismoRESUMO
Red kidney bean (Phaseolus vulgaris) is consumed worldwide as a vegetarian protein source. But, at the same time the allergenicity potential of red kidney bean is a matter of concern. This study is aimed towards purification, characterization, thermal stability, proteolytic digestion and allergenicity assessment of one of the clinically relevant allergens of red kidney bean. The purification of red kidney bean allergic protein was carried out with the help of column chromatography, IgE immunoblotting and reverse phase high-pressure liquid chromatography (RP-HPLC). The purified protein was characterized by peptide mass finger printing (PMF) and studied for its thermal stability, and proteolytic resistance using simulated gastric fluid (SGF) assay. The allergenicity potential of the purified protein was studied in BALB/c mice. The purified protein was identified as leucoagglutinating phytohemagglutinin (PHA-L) with molecular weight 29.5 kDa. The PHA-L showed resistance to heat as well as proteolytic enzyme. Higher levels of total IgE, specific IgE, and histamine were observed in PHA-L treated BALB/c mice when compared to control. Overall, PHA-L possesses characteristics of allergens and may play a potential role in the red kidney bean induced allergy.
Assuntos
Hipersensibilidade/imunologia , Fito-Hemaglutininas/imunologia , Fito-Hemaglutininas/isolamento & purificação , Proteínas de Plantas/imunologia , Proteínas de Plantas/isolamento & purificação , Animais , Feminino , Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Phaseolus/química , Phaseolus/imunologia , ProteóliseRESUMO
It is mandatory to assess the allergenic potential of genetically modified (GM) crops before their commercialization. Recently, a transgene [Calcineurin B-like (CBL) protein] has been introduced into tobacco plant to make the crop salt resistance. Therefore, it was felt necessary to assess the allergenic potential of the cbl gene product, which was introduced and expressed in Nicotiana tabacum (tobacco) plant and compared the allergenic effects with the wild-type (WT) counterpart. Bioinformatic analysis revealed that there was no significant sequence homology with known allergens. Also, no difference between the protein digestibility profiles of GM and WT tobacco was found. Rapid digestion of CBL protein (Mol Wt 35 kDa) by simulated gastric fluid (SGF) indicated reduced chances of this protein to induce allergenicity. In addition, BALB/c mice sensitized by intraperitoneal administration of WT and GM tobacco protein showed comparable levels of clinical score, specific IgE, IgG1, histamine level, similar effect on different organs as well as IgE binding proteins. These findings indicate that insertion of cbl gene in tobacco did not cause any additional allergic risk to consumer and the GM and native tobacco proteins behave similarly in both in vitro and in vivo situations even after genetic modification.
Assuntos
Alérgenos/imunologia , Nicotiana/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Tolerância ao Sal/genética , Animais , Biologia Computacional , Produtos Agrícolas/genética , Produtos Agrícolas/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Imunidade Vegetal , Proteínas de Plantas/imunologia , Nicotiana/imunologiaRESUMO
Our prior studies have indicated that ochratoxin A (OTA), a mycotoxin, has skin tumor initiating activity. In the present investigation, skin tumor promoting activity of OTA and the mechanism/(s) involved therein was undertaken. A single topical application of OTA (100 nmol/mouse) caused significant enhancement in short-term markers of skin tumor promotion such as ornithine decarboxylase activity, DNA synthesis, hyperplasia as well as expression of cyclin-D1 and COX-2 in mouse skin. In a two-stage mouse skin tumorigenesis protocol, twice-weekly exposure of OTA (50 nmol/mouse) to 7,12-dimethylbenz[α]anthracene (120 nmol/mouse) initiated mice skin for 24 weeks leads to tumor formation. Further, exposure of primary murine keratinocytes (PMKs) with non-cytotoxic dose of OTA (5.0 µM) caused (i) significant enhancement of DNA synthesis, (ii) enhanced phosphorylation and subsequent activation of epidermal growth factor receptor (EGFR) and its downstream signaling pathways viz Akt, ERK1/2, p38 and JNK mitogen-activated protein kinases (MAPKs), (iii) overexpression of c-jun, c-fos, cyclin-D1 and COX-2 and (iv) increased binding of nuclear factor-kappaB (NF-κB) and AP-1 transcription factors to the promoter region of cyclin-D1 and COX-2 genes. It was also observed that knocking down the messenger RNA expression of NF-κB, c-jun, c-fos, cyclin-D1 and COX-2 results in significant inhibition in OTA-induced PMKs proliferation. These results suggest that OTA has cell proliferative and tumor-promoting potential in mouse skin, which involves EGFR-mediated MAPKs and Akt pathways along with NF-κB and AP-1 transcription factors and that cyclin-D1 and COX-2 are the target genes responsible for tumor-promoting activity of OTA.
Assuntos
Carcinógenos/farmacologia , Proliferação de Células/efeitos dos fármacos , Ciclina D1/genética , Ciclo-Oxigenase 2/genética , NF-kappa B/metabolismo , Ocratoxinas/farmacologia , Neoplasias Cutâneas/metabolismo , Fator de Transcrição AP-1/metabolismo , 9,10-Dimetil-1,2-benzantraceno , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclina D1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Ativação Enzimática , Epiderme/efeitos dos fármacos , Epiderme/enzimologia , Epiderme/patologia , Receptores ErbB/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Hiperplasia/induzido quimicamente , Hiperplasia/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/fisiologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/genética , NF-kappa B/fisiologia , Ornitina Descarboxilase/metabolismo , Fosforilação , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , Neoplasias Cutâneas/induzido quimicamente , Fator de Transcrição AP-1/fisiologia , Ativação Transcricional/efeitos dos fármacosRESUMO
Red kidney bean (Phaseolus vulgaris L.) is one the most commonly consumed legumes that requires an in depth understanding of its allergenicity. Therefore, the aim of this study was to explore the allergenicity of red kidney bean proteins following oral exposure in BALB/c mice and elucidate the levels of Th1/Th2 transcription factors induced by red kidney bean proteins in rat basophilic leukemia cells (RBL-2H3 cells) passively sensitized with the sera of red kidney bean sensitized mice. Red kidney bean proteins showed enhanced levels of total and specific IgE, anaphylactic symptoms, thymic stromal lymphopoietin (TSLP) and peritoneal albumin over control. Enhanced release of ß-hexosaminidase along with up regulated expressions of GATA-3, STAT-6, T-bet, c-MAF and NFAT were observed in the RBL-2H3 cells exposed with red kidney bean proteins when compared to that of the controls. Taken together, exposure of red kidney bean proteins may cause allergic symptoms in mice and the ambivalent effect on Th2/Th1 transcription factors in RBL-2H3 cells.
Assuntos
Anafilaxia/imunologia , Hipersensibilidade Alimentar/imunologia , Phaseolus/imunologia , Proteínas de Plantas/imunologia , Células Th1/imunologia , Células Th2/imunologia , Animais , Western Blotting , Linhagem Celular Tumoral , Feminino , Fator de Transcrição GATA3/análise , Fator de Transcrição GATA3/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Transcrição NFATC/análise , Fatores de Transcrição NFATC/imunologia , Proteínas Proto-Oncogênicas c-maf/análise , Proteínas Proto-Oncogênicas c-maf/imunologia , Distribuição Aleatória , Ratos , Organismos Livres de Patógenos Específicos , Proteínas com Domínio T/análise , Proteínas com Domínio T/imunologia , beta-N-Acetil-Hexosaminidases/análise , beta-N-Acetil-Hexosaminidases/imunologiaRESUMO
Food induced allergic manifestations are reported from several parts of the world. Food proteins exert their allergenic potential by absorption through the gastrointestinal tract and can even induce life threatening anaphylaxis reactions. Among all food allergens, legume allergens play an important role in induction of allergy because legumes are a major source of protein for vegetarians. Most of the legumes are cooked either by boiling, roasting or frying before consumption, which can be considered a form of thermal treatment. Thermal processing may also include autoclaving, microwave heating, blanching, pasteurization, canning, or steaming. Thermal processing of legumes may reduce, eliminate or enhance the allergenic potential of a respective legume. In most of the cases, minimization of allergenic potential on thermal treatment has generally been reported. Thus, thermal processing can be considered an important tool by indirectly prevent allergenicity in susceptible individuals, thereby reducing treatment costs and reducing industry/office/school absence in case of working population/school going children. The present review attempts to explore various possibilities of reducing or eliminating allergenicity of leguminous food using different methods of thermal processing. Further, this review summarizes different methods of food processing, major legumes and their predominant allergenic proteins, thermal treatment and its relation with antigenicity, effect of thermal processing on legume allergens; also suggests a path that may be taken for future research to reduce the allergenicity using conventional/nonconventional methods.
Assuntos
Alérgenos/imunologia , Fabaceae/efeitos adversos , Manipulação de Alimentos/métodos , Hipersensibilidade Alimentar/imunologia , Proteínas de Plantas/imunologia , Temperatura Alta , HumanosRESUMO
WHO has highlighted the need to evaluate dermal toxicity of mycotoxins including Patulin (PAT), detected in several fruits. In this study the skin carcinogenic potential of topically applied PAT was investigated. Single topical application of PAT (400 nmol) showed enhanced cell proliferation (~2 fold), along with increased generation of ROS and activation of ERK, p38 and JNK MAPKs, in mouse skin. PAT exposure also showed activation of downstream target proteins, c-fos, c-Jun and NF-κB transcription factors. Further, single topical application of PAT (400 nmol) followed by twice weekly application of TPA resulted in tumor formation after 14 weeks, indicating the tumor initiating activity of PAT. However no tumors were observed when PAT was used either as a complete carcinogen (80 nmol) or as a tumor promoter (20 nmol and 40 nmol) for 25 weeks. Histopathological findings of tumors found in PAT/TPA treated mice showed that these tumors were of squamous cell carcinoma type and similar to those found in the positive control group (DMBA/TPA) along with significant increase of lipid peroxidation and decrease in free sulfydryls, catalase, superoxide dismutase and glutathione reductase activities. The results suggest the possible role of free radicals in PAT mediated dermal tumorigenicity involving MAPKs.
Assuntos
Proteínas Quinases Ativadas por Mitógeno/fisiologia , Patulina/toxicidade , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/enzimologia , Animais , Testes de Carcinogenicidade/métodos , Feminino , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Distribuição Aleatória , Espécies Reativas de Oxigênio/metabolismoRESUMO
Development of genetically modified (GM) crops is on increase to improve food quality, increase harvest yields, and reduce the dependency on chemical pesticides. Before their release in marketplace, they should be scrutinized for their safety. Several guidelines of different regulatory agencies like ILSI, WHO Codex, OECD, and so on for allergenicity evaluation of transgenics are available and sequence homology analysis is the first test to determine the allergenic potential of inserted proteins. Therefore, to test and validate, 312 allergenic, 100 non-allergenic, and 48 inserted proteins were assessed for sequence similarity using 8-mer, 80-mer, and full FASTA search. On performing sequence homology studies, ~94% the allergenic proteins gave exact matches for 8-mer and 80-mer homology. However, 20 allergenic proteins showed non-allergenic behavior. Out of 100 non-allergenic proteins, seven qualified as allergens. None of the inserted proteins demonstrated allergenic behavior. In order to improve the predictability, proteins showing anomalous behavior were tested by Algpred and ADFS separately. Use of Algpred and ADFS softwares reduced the tendency of false prediction to a great extent (74-78%). In conclusion, routine sequence homology needs to be coupled with some other bioinformatic method like ADFS/Algpred to reduce false allergenicity prediction of novel proteins.
Assuntos
Alérgenos/imunologia , Hipersensibilidade Alimentar/imunologia , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas/imunologia , Alérgenos/genética , Qualidade de Produtos para o Consumidor , Alimentos Geneticamente Modificados/efeitos adversos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos adversos , Medição de Risco/métodos , Homologia de Sequência de Aminoácidos , SoftwareRESUMO
Patulin (PAT), a mycotoxin found in apples, grapes, oranges, pear and peaches, is a potent genotoxic compound. WHO has highlighted the need for the study of cutaneous toxicity of PAT as manual labour is employed during pre and post harvest stages, thereby causing direct exposure to skin. In the present study cutaneous toxicity of PAT was evaluated following topical application to Swiss Albino mice. Dermal exposure of PAT, to mice for 4 h resulted in a dose (40-160 mug/animal) and time (up to 6 h) dependent enhancement of ornithine decarboxylase (ODC), a marker enzyme of cell proliferation. The ODC activity was found to be normal after 12 and 24 h treatment of patulin. Topical application of PAT (160 mug/100 mul acetone) for 24-72 h caused (a) DNA damage in skin cells showing significant increase (34-63%) in olive tail moment, a parameter of Comet assay (b) significant G 1 and S-phase arrest along with induction of apoptosis (2.8-10 folds) as shown by annexin V and PI staining assay through flow cytometer. Moreover PAT leads to over expression of p(21/WAF1) (3.6-3.9 fold), pro apoptotic protein Bax (1.3-2.6) and tumor suppressor wild type p(53) (2.8-3.9 fold) protein. It was also shown that PAT induced apoptosis was mediated through mitochondrial intrinsic pathway as revealed through the release of cytochrome C protein in cytosol leading to enhancement of caspase-3 activity in skin cells of mice. These results suggest that PAT has a potential to induce DNA damage leading to p(53) mediated cell cycle arrest along with intrinsic pathway mediated apoptosis that may also be correlated with enhanced polyamine production as evident by induction of ODC activity, which may have dermal toxicological implications.
Assuntos
Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/genética , Dano ao DNA/efeitos dos fármacos , Genes p53/efeitos dos fármacos , Mutagênicos/toxicidade , Patulina/toxicidade , Fenômenos Fisiológicos da Pele/genética , Proteína X Associada a bcl-2/genética , Animais , Caspase 3/biossíntese , Caspase 3/genética , Proliferação de Células/efeitos dos fármacos , Ensaio Cometa , Citocromos c/biossíntese , Citocromos c/genética , Immunoblotting , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Ornitina Descarboxilase/biossíntese , Ornitina Descarboxilase/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Leguminous crops are the main source of protein in Asian subcontinent including India and their proteins may induce allergic reactions in sensitized individuals. Pepsin resistance of proteins is a characteristic feature of most of the allergens. Simulated gastric fluid (SGF) assay as validated by digestion of purified known allergenic and non-allergenic proteins was the basis of this study. Purified allergenic proteins were stable to SGF digestion contrary to rapidly digested non-allergenic proteins. Crude proteins extracts (CPE) of soybean, peanut, chickpea, black gram, kidney bean and Bengal gram were digested in vitro to detect their non-digestible proteins. Six proteins from soybean and seven from peanut remained undigested after SGF digestion. Likewise, seven proteins from chickpea (70, 64, 55, 45, 35, 20 and 18 kDa), ten from black gram (47, 30, 29, 28, 26, 24, 22, 16, 14 and 12 kDa), five from kidney bean (45, 29, 24, 20 and 6.5 kDa) and one from Bengal gram (20 kDa) remained undigested in SGF. Most of the proteins stable in SGF for more than 2 min showed similarity with characterized allergens on the basis of their molecular weights as in case of soybean, peanut, chickpea and black gram. Also, soybean and chickpea stable proteins showed IgE binding property with respective allergic patient's sera. The non-digestible proteins from the chickpea, black gram, kidney bean and Bengal gram are being reported for the first time by our group. IgE binding of SGF resistant soybean and chickpea proteins is being reported first time as well.
Assuntos
Antígenos de Plantas/imunologia , Proteínas Alimentares/imunologia , Fabaceae/imunologia , Hipersensibilidade Alimentar/imunologia , Suco Gástrico/imunologia , Proteínas de Plantas/imunologia , Antígenos de Plantas/metabolismo , Proteínas Alimentares/metabolismo , Digestão/imunologia , Fabaceae/metabolismo , Suco Gástrico/metabolismo , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Proteínas de Plantas/metabolismoRESUMO
INTRODUCTION: Previously, we have reported the amelioration of ad-AF induced hepatotoxicity with the exogenous supplementation of glutathione (GSH) without compromising the anti-tumor effect of ad-AF in ascites tumor model of mice with transplantable Ehrlich's Ascites Tumor cells. Cellular uptake of glutathione (GSH) has its own limitations, therefore exogenous supplementation of L-cysteine (Cys) was tried to reduce the toxicity of ad-AF by providing -SH contents without compromising the anti-tumor property of adsorbed ascites fluid (ad-AF). RESULTS: A significant increase in mean survival time (MST) of tumor bearing mice from 18.1 days to 32.9 days with exogenous supplementation of Cys was observed. Cys supplementation did not alter decline in body-weight gain, tumor cell counts as well as decrease in the viability of tumor cells in ascites tumor bearing animals. Similarly, Cys has been helpful to restore the hepatic -SH contents upto the levels of -SH content in tumor control group. The exogenous supplementation of Cys along with ad-AF has been helpful to restore the decline in the activities of phase-I and enhanced levels of glutathione-S-transferase (GST). The changes in the activities of different enzymes of phase-I and phase-II indicate the reduction in toxic insult induced by the therapeutic material (ad-AF). However, ad-AF treatment could not prevent tumor bearers from natural death due to tumor progression but significantly reduced the rate of tumor progression. CONCLUSIONS: Our study suggests that exogenous supplementation of Cys alongwith ad-AF could have a potential to be developed as a modality for the treatment of ascites tumor at least at experimental level.
RESUMO
INTRODUCTION: Hepatotoxicity along with enhanced mortality has remained a major concern during the development of antitumor therapy with the use of cell-free ascites fluid adsorbed (ad-AF) over Protein-A-containing Staphylococcus aureus Cowan I (SAC). Major issue with ad-AF inoculation is the significant depletion of hepatic glutathione (GSH). Exogenous supplementation of -SH contents to the host has offered an encouraging hope to explore the possibilities to use ad-AF as a therapeutic material due to its antitumor effects. GSH and l-cysteine have shown a promise with the recovery of -SH contents as well as the recovery of phase I and phase II biotransformation enzymes. Aforementioned observations prompted us to try other -SH donors. MATERIALS AND METHODS: Therefore, in this study, N-acetylcysteine (NAC) was used as an exogenous source to provide -SH contents to reduce hepatotoxicity and mortality induced by ad-AF treatment. RESULTS: Exogenous supplementation of NAC along with ad-AF treatment to ascites tumor bearers has shown a significant protection against hepatotoxicity and mortality caused by ad-AF. NAC substitution along with ad-AF has significantly enhanced the mean survival time (MST), without altering the antitumor effect of ad-AF as evident from tumor cell counts and viability. DISCUSSION: NAC supplementation has been successful to recover hepatic -SH contents along with the significant recovery of phase I and phase II biotransformation enzymes. Marker enzymes for liver injury have also given clear-cut indications for the recovery of tumor bearers from hepatotoxicity induced by ad-AF. CONCLUSION: This study has shown that exogenous supplementation of NAC protects the host from the enhanced mortality and hepatotoxicity induced by ad-AF. These observations offer a hope to develop ad-AF as one of the probable treatment strategies for ascites tumors at least at experimental levels.
RESUMO
Tree nut along with peanut are among the most potent food allergens, responsible for frequently inducing the IgE-mediated hypersensitivity reaction. Our aim was identification, purification of Buchanania lanzan (Bl-11â¯kDa) protein along with characterization and assessment of allergenic potential of clinically relevant allergen. Further study was executed in clinical samples of sensitive patients, BALB/c mice, and in-vitro. A major IgE binding 11-kDa protein from Buchanania lanzan was purified by anion exchange chromatography, reverse phase high pressure liquid chromatography (RP-HPLC) and characterized using peptide mass fingerprinting (PMF). Buchanania lanzan (Bl-11â¯kDa) protein shows the pepsin resistance and depicts IgE interacting capacity to Buchanania lanzan allergic patient's sera as well as sensitized mice sera. It also showed increase in the allergic mediator's like IgE, IgG1, histamine levels in sensitized mice sera. Further study was carried out in-vitro (RBL-2H3 cells) and increased release mast cell degranulation mediators such as ß-hexosaminidase, histamine, CysL and PGD2 in the culture supernatant was found. The activation of Th2 cytokines/transcription factors and expression of molecular markers in the downstream of mast cell signaling were up-regulated while the Th1 transcriptional factor (T-bet) was decreased in Bl-11â¯kDa protein treated mice. Conclusively, our study demonstrates Buchanania lanzan purified protein to be potential allergen that may generate an allergic reaction in sensitized individuals, and one of the most important IgE binding protein responsible for its allergenicity.
Assuntos
Alérgenos/análise , Anacardiaceae/imunologia , Imunoglobulina E/metabolismo , Proteínas de Nozes/imunologia , Alérgenos/imunologia , Animais , Feminino , Humanos , Imunoglobulina E/sangue , Intestinos/patologia , Pulmão/patologia , Mastócitos/química , Mastócitos/imunologia , Mastócitos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Hipersensibilidade a Noz/sangue , Hipersensibilidade a Noz/imunologia , Proteínas de Nozes/análise , Proteínas de Nozes/isolamento & purificação , Transdução de SinaisRESUMO
Mustard is widely used in a variety of foods/food products to enhance the flavor and nutritional value that subsequently raise the risk of hypersensitivity reactions. Mustard allergy has been reported for many years and is increasing gradually especially in the areas where its consumption is comparatively higher, and it may be considered among the most important food allergies. A number of relevant clinical studies focused on mustard-induced allergic manifestations are summarized in the current review. In addition, the knowledge regarding the immunological as well as biochemical characteristics of mustard allergens that have been known till date and their cross-reactivity with other food allergens have also been discussed here. Notably, mustard may also be present as a hidden allergen in foods; therefore, it is important to recognize food products that may contain mustard as it may pose potential risk for the allergic individuals. Additionally, the better understanding of the underlying mechanism in mustard allergy is a prerequisite for the development of specific therapeutic procedures. Conclusively, mustard sensitivity should be routinely tested in patients with idiopathic anaphylaxis for the safety of the allergic patients.
Assuntos
Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/imunologia , Nível de Saúde , Mostardeira/imunologia , Adulto , Alérgenos/imunologia , Anafilaxia/imunologia , Criança , Reações Cruzadas/imunologia , Feminino , Manipulação de Alimentos , Humanos , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Mostardeira/química , Testes do Emplastro , Óleos de Plantas , Pólen/imunologiaRESUMO
In the course of analyzing amino acid sequence of an allergen (≈20 kDa), we found this protein has a homology with the amino acid sequence of putative α-Dioxygenase fragment (ADF). Allergy caused by many allergens having an enzymatic activity have been reported previously, but allergenicity to neither α-Dioxygenase enzyme nor to it's any constituents has been reported. We sought to purify an ADF (≈19.5 kDa) from chickpea to investigate it's inherent allergic potential in BALB/c mice. The ADF showed IgE-affinity in sera of sensitized BALB/c mice and allergic patients. Enhanced levels of histamine, specific IgE as well as IgG1, IL-4, IL-17, IL-6, IL-2 and IL-10 were observed in the sera of mice treated with ADF allergen. A positive skin Type 1 test and elevated number of mast cells were found in the treated mice. Apart from this, enhanced number of immune cells i.e. CD19+ and CD4+ were also noticed in the ADF treated group. Higher expressions of IL-4 as well as GATA-3 and prominent histological changes were observed in tissues of treated animals. Furthermore, expressions of Th2 cytokines, associated transcription factors and mast cell signaling proteins were also increased at mRNA and protein levels in the intestines of ADF treated mice. Conclusively, present study demonstrated that ADF with molecular weight of 19.5 kDa is a clinical relevant allergen which causes allergic immune responses in BALB/c mice and may play a pivotal role in allergy caused by food containing α-Dioxygenase enzyme in sensitive individuals.