RESUMO
The aim of this study was to investigate the mechanisms involved in the apoptosis of HeLa cells due to 2,3-dehydrosilybin (DHS) treatment. DHS treatment over 24 h significantly inhibited cell viability and induced apoptosis in a dose-dependent manner. It also triggered the cleavage of caspase-8, caspase-9, caspase-3, and PARP, and significantly increased caspase-3 activity in a dose-dependent manner. Moreover, it triggered the depolarization of the mitochondrial membrane potential (Δψm), the release of cytochrome c into the cytosol, the cleavage of Bid, and the downregulation of Bcl-2 in a dose-dependent manner. Furthermore, z-VAD-fmk (a pan-caspase inhibitor) and z-IETD-fmk (a specific caspase-8 inhibitor) abolished the DHS-induced activation of the caspase-8, -9, and -3, cleavage of PARP, the depolarization of Δψm, the release of cytochrome c, the cleavage of Bid, and the downregulation of Bcl-2. Taken together, these results suggest that DHS-induced apoptosis is mediated by a caspase-dependent pathway in human HeLa cells.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Silimarina/farmacologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Inibidores de Caspase/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Regulação para Baixo/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Células HeLa , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteólise/efeitos dos fármacos , SilibinaRESUMO
Isoegomaketone (IK) is an essential oil component of Perilla frutescens (L.), but the mechanism by which IK induces apoptosis has never been studied. The purpose of this study was to elucidate the IK-induced apoptotic pathway in DLD1 human colon cancer cells. We observed that IK treatment over 24 h significantly inhibited cell viability in a dose-dependent manner. We also found that IK triggered cleavage of PARP. Moreover, IK treatment resulted in cleavage of caspase-8, -9, and -3 in a dose- and time-dependent manner. IK treatment also resulted in cleavage of Bid and translocation of Bax, and triggered the release of cytochrome c from the mitochondria to the cytoplasm. Furthermore, it resulted in the translocation of apoptosis inducing factor (AIF), a caspase-independent mitochondrial apoptosis factor, from the mitochondria into the nucleus. Overall, these results suggest that IK induces apoptosis through caspase-dependent and capase-independent pathways in DLD1 cells.
Assuntos
Fator de Indução de Apoptose/metabolismo , Caspases/metabolismo , Citocromos c/metabolismo , Furanos/administração & dosagem , Furanos/química , Cetonas/administração & dosagem , Cetonas/química , Mitocôndrias/efeitos dos fármacos , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química , Apoptose , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Caspases/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Humanos , Mitocôndrias/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
Prolonged disuse of skeletal muscle causes significant loss of myofibrillar contents, muscle tension, and locomotory capacity. However, hibernating mammals like bats appear to deviate from this trend. Although low functional demands during winter dormancy has been implicated as a factor contributing to reduced muscle loss, the precise mechanism that actively prevents muscle atrophy remains unclear. We explored proteomic and molecular assessments of bat muscle to test a hypothesis that expression levels of major myofibrillar proteins are retained during hibernation, with periodic arousals utilized as a potential mechanism to prevent disuse atrophy. We examined changes in myofibrillar contents and contractile properties of the pectoral or biceps brachii muscles of the bat Murina leucogaster in summer active (SA), hibernation (HB) and early phase of arousal (AR) states. We found the bat muscles did not show any sign of atrophy or tension reduction over the 3-month winter dormancy. Levels of most sarcomeric and metabolic proteins examined were maintained through hibernation, with some proteins (e.g., actin and voltage dependent anion channel 1) 1.6- to 1.8-fold upregulated in HB and AR compared to SA. Moreover, expression levels of six heat shock proteins (HSPs) including glucose-regulated protein 75 precursor were similar among groups, while the level of HSP70 was even 1.7-fold higher in HB and AR than in SA. Thus, considering the nature of arousal with strenuous muscle shivering and heat stress, upregulation or at least balanced regulation of the chaperones (HSPs) would contribute to retaining muscle properties during prolonged disuse of the bat.
Assuntos
Hibernação , Proteínas dos Microfilamentos/análise , Atrofia Muscular , Proteômica , Animais , Nível de Alerta , Quirópteros , Proteínas de Choque Térmico HSP70 , Proteínas de Choque Térmico , Mamíferos , Tono Muscular , Miofibrilas/química , Estações do Ano , Regulação para CimaRESUMO
This study was aimed to evaluate the apoptotic effects of thiosulfinates purified from Allium tuberosum L. on PC-3 human prostate cancer cells, and to elucidate detailed apoptosis mechanisms. Thiosulfinates significantly decrease viable cell numbers in dose- and time-dependent manners by apoptotic cell death via DNA fragmentation, chromatin condensation, and an increased sub-G1 phase. Apoptosis induced by thiosulfinates is associated with the activation of initiator caspase-8 and -9, and the effector caspase-3. In this study, thiosulfinates stimulated Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. Thiosulfinates decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. Thiosulfinates also increased the expression of AIF, a caspase-independent mitochondrial apoptosis factor, in PC-3 cells. These results indicate that thiosulfinates from A. tuberosum L. inhibit cell proliferation and induce apoptosis in PC-3 cells, which may be mediated via both caspase-dependent and -independent pathways.
Assuntos
Adenocarcinoma/tratamento farmacológico , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Cebolinha-Francesa/química , Neoplasias da Próstata/tratamento farmacológico , Ácidos Sulfínicos/farmacologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Clorometilcetonas de Aminoácidos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Apoptose/fisiologia , Fator de Indução de Apoptose/metabolismo , Inibidores de Caspase , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Colágeno Tipo XI/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ácidos Sulfínicos/isolamento & purificação , Proteína X Associada a bcl-2/metabolismoRESUMO
The present study was attempted to evaluate the effects of gamma-irradiated doxorubicin (IRD) on spleen cell proliferation, cytokines release (IFN-gamma and IL-2) and lung metastasis in mice. Gamma irradiation induced degradation of doxorubicin molecule and cytotoxicity on melanoma (B16BL6) and myoblast (H9c2) cell lines were determined by high performance liquid chromatography (HPLC) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazole) assay, respectively. Non-irradiated doxorubicin (NIRD) was used as a control. The mice injected with NIRD (2mg/kg body weight for 5 days, 24h interval) showed a considerable decrease (P<0.05) in the body, spleen weight, proliferation and cytokine release (IL-2 and IFN-gamma) as compared to control. However, a non-significant variation was observed in IRD treated mice compared with normal. Tumor bearing mice treated with NIRD and IRD (2mg/kg body weight, five doses at 48 h interval) showed diverse results on spleen cell cytokine release, proliferation and metastasis. HPLC results revealed the formation of several trace level degradation (P<0.05) products of IRD. IRD displayed a non-significant variation of cytotoxicity on B16BL6 cells, and low percentage (P<0.01) of cardiotoxicity on H9c2 cells as compared to NIRD. Altogether, this present study emphasis that gamma irradiation altered the property of doxorubicin.
Assuntos
Doxorrubicina/farmacologia , Doxorrubicina/efeitos da radiação , Raios gama , Neoplasias Pulmonares/tratamento farmacológico , Baço/efeitos dos fármacos , Animais , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/efeitos da radiação , Peso Corporal/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Doxorrubicina/química , Ensaios de Seleção de Medicamentos Antitumorais , Estabilidade de Medicamentos , Interferon gama/biossíntese , Interleucina-2/biossíntese , Neoplasias Pulmonares/secundário , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mioblastos/efeitos dos fármacos , Transplante de Neoplasias , Tamanho do Órgão/efeitos dos fármacos , Baço/citologia , Baço/metabolismoRESUMO
The hepatoprotective efficacy of irradiated hyaluronic acid (HA) on acetaminophen (APAP) induced acute hepatotoxicity was investigated. BALB/c mice (4-6 weeks of age) were pretreated with unirradiated HA (UIHA), 5 and 50 kGy gamma irradiated HA (GIHA) for 14 days and were dosed APAP (500 mg/kg b.wt). After 9h of APAP dosing animals were euthanized. The degree of acute hepatotoxicity was measured by aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The expression of interferon-gamma (IFN-gamma) in serum and alpha-and mu-class of gluthathione-S-transferase (GSTs), CYP 2E1 class of cytochrome monooxygenase and glutathione (GSH) in liver were quantified. Histological evaluation was done by Hematoxiylin and Eiosin staining, Periodic acid schiffs staining, Manson trichrome staining and histological scorings were done. The degree of acute hepatotoxicity was markedly lower in UIHA and 5 kGy than in 50 kGy GIHA pretreated group and there was negligible difference between 5 and 50 kGy GIHA pretreated group. The expression of interferon-gamma (IFN-gamma) was significantly (P<0.05) suppressed in 5 and 50 kGy GIHA pretreated group. Histological scorings showed a significant protection of liver in UIHA and 5 kGy GIHA pretreated mice. Expression of alpha class GSTs was significantly increased in 5 and 50 kGy GIHA pretreated group. To conclude suppression of IFN-gamma and increase in alpha-class GSTs expression may exert a protective role in acute hepatotoxicity of APAP and 5 kGy GIHA showed comparable protective effect to that of UIHA.
Assuntos
Acetaminofen/toxicidade , Raios gama , Ácido Hialurônico/farmacologia , Fígado/efeitos dos fármacos , Animais , Interferon gama/metabolismo , Fígado/patologia , Testes de Função Hepática , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Hyaluronic acid (Hyaluronan, HA) was depolymerised by gamma irradiation and its structural changes and antioxidant activities were investigated. The structural changes of gamma irradiated HA were studied by gel-permeation chromatography (GPC), viscosity, pH, Hunter colour measurement, UV spectrophotometry, and FT-IR spectroscopy. The results demonstrated that gamma irradiation decreased molecular weight size, viscosity and pH of the hyaluronic acid and its colour turned to intense yellow. UV spectra of the irradiated HA showed a change at 265nm, which indicates the formation of double bonds. Differences in the height and shape of certain absorption bonds of FT-IR spectra in the range 1700-1750cm(-1) were also observed, which is associated with the formation of carboxylic acid. From these structural changes of the HA, gamma irradiation may have a role in the formation of pyrancarboxylic acid rings. DPPH radical scavenging ability and the reducing power of gamma irradiated HA were significantly higher than that of non-irradiated HA. However, non-irradiated and irradiated HA did not show significant differences in the Rancimat test.
RESUMO
It is well known that gamma (gamma)-ray irradiation results in the alteration of biological function of bioactive materials such as proteins, saccharides and lipids. In this study the effect of gamma-irradiation on the chemical and immunological property of an allergen, ovalbumin (OVA), was investigated. Irradiation of more than 10 kGy resulted in the alteration of the structure of OVA. However, OVA treated with 10 kGy irradiation (10 kGy-OVA), but not 100 kGy-OVA, fully maintained immunological reactivity to a monoclonal antibody specific to the intact allergen (clone 14). Mice immunized with 10 kGy- as well as 100 kGy-OVA showed significantly lower antibody response to the allergen than those with intact OVA in a gamma-ray dosage-dependent manner. Especially immunization of both 10 kGy- and 100 kGy-OVA induced a significant decrease of OVA-specific IgE. Splenocytes of mice immunized with irradiated OVA showed a significant reduction in OVA-specific T cell proliferation and the secretion of Th1-type (IFN-gamma and IL-2) and Th2-type cytokines (IL-4 and IL-6). The expression of T cell activation markers such as CD25 and CD44 was also down-regulated in T cells of mice immunized with irradiated OVAs. These results suggest that gamma-ray irradiation of OVA suppress humoral and cellular immune responses specific to the allergen OVA, and the modification method with gamma-irradiation may be available for the control of allergy.
Assuntos
Alérgenos/efeitos da radiação , Raios gama , Ovalbumina/efeitos da radiação , Linfócitos T/efeitos dos fármacos , Alérgenos/imunologia , Alérgenos/farmacologia , Animais , Anticorpos/sangue , Anticorpos/imunologia , Proliferação de Células/efeitos dos fármacos , Feminino , Receptores de Hialuronatos/imunologia , Subunidade alfa de Receptor de Interleucina-2/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Ovalbumina/farmacologia , Baço/citologia , Linfócitos T/imunologiaRESUMO
In this study we isolated crude thiosulfinates from Allium tuberosum L. using CH 2Cl 2 and then with silica gel column chromatography purified S-methyl methanthiosulfinate and S-methyl 2-propene-1-thiosulfinate from the crude thiosulfinates. Subsequently, in vitro cytotoxicities against human cancer cells and in vivo antitumor activities of the thiosulfinates were investigated. Their cytotoxicities were strong in human cancer cells, in the order of S-methyl 2-propene-1-thiosulfinate, crude thiosulfinates, and S-methyl methanthiosulfinate. When thiosulfinates were administered consecutively for 7 days at 10, 30, and 50 mg/kg ip, in mice, we found significant increases in the life spans of mice that had been inoculated with Sacorma-180 tumor cells. The crude thiosulfinates also induced apoptosis in MCF-7 cancer cells. These results suggest that thiosulfinates from Allium tuberosum L. inhibit the proliferation of cancer cells via apoptosis and have antitumor activities.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Cebolinha-Francesa/química , Ácidos Sulfínicos/uso terapêutico , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacocinética , Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Camundongos , Transplante de Neoplasias , Sarcoma 180/tratamento farmacológico , Ácidos Sulfínicos/isolamento & purificação , Ácidos Sulfínicos/farmacologiaRESUMO
Monascus isolate number 711, which is capable of producing monacolin K as an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the key enzyme of cholesterol synthesis, was isolated from Ang-kak, the red yeast rice koji. To increase the monacolin K-producing activity of the strain, spore suspensions of the strain were subjected to gamma-irradiation. One thousand mutants were generated via gamma-irradiation and screened using bioassay and high performance liquid chromatography analysis. Several mutants with higher productivities of monacolin K than that of the parent strain were primarily selected. Mutant KU609 was finally selected because of its characteristics of high monacolin K production and non-citrinin-producing activity under our test conditions. Response surface methodology was used to analyze the effect of culture medium on the production of monacolin K in mixed solid-state cultures. The optimal values of nutritional ingredients for the maximal production were soytone, glucose, MgSO4, and barley at concentrations of 0.5 g, 0.48 g, 0.053 g, and 9 g, respectively. The final monacolin K production of Monascus KU609 was increased almost 100-fold compared to that of the parent strain.
Assuntos
Raios gama , Inibidores de Hidroximetilglutaril-CoA Redutases , Lovastatina/biossíntese , Monascus/genética , Monascus/metabolismo , Mutação , Cromatografia Líquida de Alta Pressão , Citrinina/análise , Meios de Cultura , Glucose , Hordeum , Lovastatina/análise , Sulfato de Magnésio , Modelos Estatísticos , Monascus/efeitos da radiação , Glycine max , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Esporos Fúngicos/efeitos da radiaçãoRESUMO
Pectin was dissolved in deionized distilled water (2%, vol/vol) and irradiated at 20 kGy using a Co-60 gamma ray irradiator. The resulting solution was dialyzed and lyophilized. The samples were separated into three groups to estimate their antioxidant and cancer cell proliferation effects: non-irradiated (0 kGy), irradiated (20 kGy), and dialyzed (20 kGy-F, mol wt <10,000) samples. Antioxidant properties of each treatment was tested by a beta-carotene-linoleic acid bleaching assay and electron donating ability and compared for antioxidant index, which indicated that the activity was higher in the order of 20 kGy-F > 20 kGy > 0 kGy. Spleen cell survival effect of the irradiated pectin (20 kGy) and dialyzed (20 kGy-F) samples was higher than the non-irradiated control (0 kGy). The pectins inhibited growth of the cancer cell in the order of 20 kGy- F > 20 kGy > 0 kGy. The Ames test revealed that none of the fractions was mutagenic, and there was no indication of a dose-dependent response for any of the samples. These results suggest that a functional pectin oligosaccharide can be produced by irradiation for the food industry without any chemical treatment.
Assuntos
Antioxidantes/farmacologia , Divisão Celular/efeitos dos fármacos , Citrus/química , Neoplasias/patologia , Pectinas/farmacologia , Pectinas/efeitos da radiação , Compostos de Bifenilo , Linhagem Celular Tumoral , Sequestradores de Radicais Livres/química , Frutas/química , Raios gama , Humanos , Ácido Linoleico/química , Ácido Linoleico/farmacologia , Testes de Mutagenicidade , Oligossacarídeos/farmacologia , Oligossacarídeos/efeitos da radiação , Oxirredução , Picratos , beta Caroteno/química , beta Caroteno/farmacologiaRESUMO
Three prepared seafood products for manufacturing a laver (dried seaweed) roll, a traditional and rapidly growing ready-to-eat meal in Korea, were selected and the effects of irradiation treatment for eliminating pathogens of public health significance were investigated. The pathogens tested were Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria ivanovii. The radiation sensitivity (D10-values or the dose required to inactivate 90% of a population) of these organisms ranged from 0.23 to 0.62 kGy in imitation crab leg, 0.31 to 0.44 kGy in surimi gel, and 0.27 to 0.44 kGy in dried seaweed. The growth of all four test organisms inoculated (10(8) CFU/g) into these foods was inhibited by irradiation during 24 h of postirradiation storage regardless of the temperature (10, 20, and 30 degrees C). L. ivanovii was not detected after a 3-kGy treatment, but the other pathogens were not detected following irradiation at 2 kGy. These studies indicated that low-dose irradiation (2 kGy or less) of prepared seafood materials can keep them microbiologically safe before manufacturing a ready-to-eat prepared meal, a laver roll.
Assuntos
Bactérias/efeitos da radiação , Qualidade de Produtos para o Consumidor , Irradiação de Alimentos , Alimentos Marinhos/microbiologia , Animais , Bactérias/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Relação Dose-Resposta à Radiação , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/efeitos da radiação , Microbiologia de Alimentos , Raios gama , Humanos , Listeria/crescimento & desenvolvimento , Listeria/efeitos da radiação , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/efeitos da radiação , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/efeitos da radiação , TemperaturaRESUMO
Physiological activity of irradiated green tea polyphenol on the human skin was investigated for further industrial application. The green tea polyphenol was separated and irradiated at 40 kGy by y-ray. For an anti-wrinkle effect, the collagenase inhibition effect was higher in the irradiated sample (65.3%) than that of the non-irradiated control (56.8%) at 200 ppm of the concentration (p < 0.05). Collagen biosynthesis rates using a human fibroblast were 19.4% and 16.3% in the irradiated and the non-irradiated polyphenols, respectively. The tyrosinase inhibition effect, which is related to the skin-whitening effect, showed a 45.2% and 42.9% in the irradiated and the non-irradiated polyphenols, respectively, at a 100 ppm level. A higher than 90% growth inhibition on skin cancer cells (SK-MEL-2 and G361) was demonstrated in both the irradiated and the non-irradiated polyphenols. Thus, the irradiation of green tea polyphenol did not change and even increased its anti-wrinkle, skin-whitening and anticancer effects on the human skin. The results indicated that irradiated green tea polyphenol can be used as a natural ingredient with excellent physiological functions for the human skin through cosmetic or food composition.
Assuntos
Antineoplásicos/farmacologia , Flavonoides/farmacologia , Melanoma/tratamento farmacológico , Fenóis/farmacologia , Envelhecimento da Pele/efeitos dos fármacos , Neoplasias Cutâneas/tratamento farmacológico , Chá , Contagem de Células , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Colágeno/biossíntese , Colágeno/metabolismo , Cosméticos , Fibroblastos/citologia , Fibroblastos/metabolismo , Irradiação de Alimentos , Humanos , Inibidores de Metaloproteinases de Matriz , Monofenol Mono-Oxigenase/antagonistas & inibidores , Polifenóis , Pele/citologiaRESUMO
Volatile N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) in irradiated pepperoni and salami sausages were determined using a gas chromatography coupled to a thermal energy analyzer (GC-TEA). These fermented sausages with aerobic or vacuum packaging were irradiated at 0, 5, 10, and 20 kGy, and then stored for 4 weeks at 4 degrees C. Both NDMA and NPYR in the fermented sausage were significantly reduced by irradiation. The vacuum packaging showed significantly lower (P < 0.05) N-nitrosamine levels than that of the aerobic ones. After storage, the contents of NDMA and NPYR in the irradiated sausage were lower than those of the non-irradiated control. Results indicated that a high dose of irradiation (>10 kGy) was needed to reduce the carcinogenic N-nitrosamines in the fermented sausage during storage and the GC-TEA analysis was effective in determining the N-nitrosamines in irradiated meats even at low trace levels.
Assuntos
Cromatografia Gasosa/métodos , Produtos da Carne/análise , Nitrosaminas/análise , Fermentação , Irradiação de Alimentos , VolatilizaçãoRESUMO
Lipid oxidation and color stability of meats treated with irradiated phytic acid were investigated during storage for 2 weeks at 4 degrees C. The phytic acid in deionized distilled water (DDW) was degraded by irradiation at 10 and 20 kGy, and the irradiated phytic acid showed a strong antiradical activity. For measuring the antioxidant effects of irradiated phytic acid in food models, beef and pork were prepared with DDW (control), irradiated (10 and 20 kGy) or non-irradiated phytic acid, and ascorbic acid as a model system. Irradiated phytic acid significantly inhibited the lipid oxidation in meats compared to the control and ascorbic acid treated samples during storage (P < 0.05). The redness of the meats treated with phytic acid had a higher value than did the control and ascorbic acid treated samples, but a significant difference was not observed in the samples treated with phytic acid regardless of irradiation treatment. Irradiated phytic acid was also effective in inhibiting the loss of heme iron and metmyoglobin formation during storage. Results indicated that irradiation might be helpful for improving the antioxidant activity of phytic acid in meats.
Assuntos
Antioxidantes/farmacologia , Cor , Carne/análise , Ácido Fítico/farmacologia , Ácido Fítico/efeitos da radiação , Ácido Ascórbico/farmacologia , Raios gama , Peroxidação de Lipídeos/efeitos dos fármacosRESUMO
The present study was undertaken to evaluate the irradiation and modified atmosphere packaging effects on emulsion-type cooked pork sausage during storage for 4 weeks. CO(2) (100%), N(2) (100%), or 25% CO(2)/75% N(2) packaged sausage were irradiated at 0, 5, and 10 kGy, and residual nitrite, residual ascorbic acid, nitrosomyoglobin (NO-Mb), color values, and their correlation were observed. Irradiation significantly reduced the residual nitrite content and caused partial reduction of NO-Mb during storage. No difference was observed in ascorbic acid content by irradiation. Irradiation decreased the Hunter color a value of sausage. CO(2) or CO(2)/N(2) packaging were more effective for reducing residual nitrite and inhibiting the loss of the red color of sausage compared to N(2) packaging. Results indicated that the proper combination of irradiation and modified atmosphere packaging could reduce the residual nitrite in sausage with minimization of color change.
Assuntos
Ácido Ascórbico/análise , Irradiação de Alimentos , Embalagem de Alimentos/métodos , Heme/análogos & derivados , Heme/análise , Produtos da Carne/análise , Nitritos/análise , Animais , Dióxido de Carbono/administração & dosagem , Cor , Conservação de Alimentos , Produtos da Carne/efeitos da radiação , Mioglobina/análise , Nitrogênio/administração & dosagem , SuínosRESUMO
The aqueous solution of alginate was irradiated by 60Co gamma-rays in the dose range of 10-500 kGy. To assess the effect of irradiation on the degradation of alginate, the irradiation-induced changes in the viscosity, molecular weight, color, monomer composition, and sequence were measured. The molecular weight of raw alginate was reduced from 300000 to 25000 when irradiated at 100 kGy. The degradation rate decreased and the chain breaks per molecule increased with increasing irradiation dose. The viscosity of irradiated alginate solution reached a near minimum as low as at 10 kGy. No appreciable color changes were observed in the samples irradiated at up to 100 kGy, but intense browning occurred beyond 200 kGy. The 13C NMR spectra showed that homopolymeric blocks, MM and GG, increased and the M/G ratio decreased with irradiation. Considering both the level of degradation and the color change of alginate, the optimum irradiation dose was found to be 100 kGy.
Assuntos
Alginatos/química , Alginatos/efeitos da radiação , Raios gama , Ácido Glucurônico/química , Ácido Glucurônico/efeitos da radiação , Ácidos Hexurônicos/química , Ácidos Hexurônicos/efeitos da radiação , Fenômenos Químicos , Físico-Química , Radioisótopos de Cobalto , Cor , Espectroscopia de Ressonância Magnética , Peso Molecular , ViscosidadeRESUMO
This study was carried out to evaluate the changes in the allergenic and antigenic properties of hen's egg albumin (ovalbumin [OVA]) with the combination of heat and gamma irradiation treatment. OVA solution samples were treated by (i) heating (sample 1), (ii) irradiation after heating (sample 2), and (iii) heating after irradiation (sample 3). Samples were isothermally heated and irradiated at the absorption dose of 10 kGy. Competitive indirect enzyme-linked immunosorbent assays (ELISAs) were performed with blood serum to test the ability of treated OVA to bind to immunoglobulin E (IgE) and mouse murine monoclonal antibody (IgG). OVA's ability to bind to mouse IgG changed upon heating at 75 degrees C, and its ability to bind to egg-allergic IgE changed upon heating at 80 degrees C. The ELISAs showed that egg-allergic IgE did not recognize OVA very well when heated at > or = 80 degrees C, while mouse IgG retained better activity under these conditions. Egg-allergic IgE binding was low both for OVA samples treated by heating and for samples treated by irradiation followed by heating. These results show that allergies induced by OVA could be effectively reduced by the combination of heat and gamma irradiation treatment.
Assuntos
Proteínas do Ovo/imunologia , Hipersensibilidade Alimentar/prevenção & controle , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Ovalbumina/imunologia , Animais , Ligação Competitiva , Proteínas do Ovo/efeitos da radiação , Ensaio de Imunoadsorção Enzimática , Raios gama , Temperatura Alta , Humanos , Camundongos , Ovalbumina/efeitos da radiação , Desnaturação ProteicaRESUMO
This study was conducted to evaluate the effect of a treatment combining gamma radiation and heating on the allergenic properties of hen's egg ovomucoid (OM) under basic pH conditions. OM solutions of 2.0 mg/ml with pHs of 7.0, 9.0, and 10.0 were gamma irradiated at 10 kGy, heated at 100 degrees C for 15 min, or both. Half of the treated pH 10.0 sample solution was restored to pH 7.4 by dialysis. OM solutions were tested by a competitive direct enzyme-linked immunosorbent assay formatted with immunoglobulin E from egg-hypersensitive patients. An equation was obtained for quantifying intact OM from the standard curve, and the detected concentration of intact OM was calculated. The concentration of intact OM decreased with irradiation or heating, and the rate of the decrease was higher for a basic pH condition than for the physiological condition. The combination of irradiation and heating was very effective in reducing the amount of intact OM regardless of the pH condition. After treatment, the restoration of the pH to 7.4 did not affect the concentration of OM. The results of this study indicate that a combination of irradiation and heating might be an effective method for reducing egg hypersensitivity resulting from OM.
Assuntos
Hipersensibilidade Alimentar/prevenção & controle , Imunoglobulina E/imunologia , Ovomucina/imunologia , Ovomucina/efeitos da radiação , Animais , Galinhas , Ovos , Ensaio de Imunoadsorção Enzimática , Raios gama , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Proteínas de Plantas/imunologia , Proteínas de Plantas/efeitos da radiação , Inibidores da Tripsina , alfa-Amilases/antagonistas & inibidoresRESUMO
Residual nitrite and N-nitrosamine levels were monitored on irradiated emulsion-type cooked pork sausage in aerobic or vacuum packaging states during storage. The sausage was irradiated at 0, 5, 10, and 20 kGy and stored at 4 degrees C for 4 weeks. The residual nitrite levels were significantly reduced by gamma irradiation (P < 0.05), whereas the vacuum packaging was more effective for nitrite reduction than aerobic packaging during storage. N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) levels were significantly reduced in the vacuum packaged sausage irradiated with 20 kGy after 4 weeks. Reduction of NPYR in aerobically packaged sausage was also found after 4 weeks by irradiating with a 5-kGy or higher dose. NDMA reduction was shown in vacuum packaging and irradiation at 20 kGy. Gamma irradiation was effective in reducing the residual nitrite all throughout storage and N-nitrosamines in sausage after storage.