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Distribution of Enterotoxigenic Clostridium perfringens Spores in U.S. Retail SpicesLee, Chi-An 07 November 2016 (has links)
246 samples of bulk and packaged spices from retail stores in the western, southeastern, southern, midwestern, and northeastern areas of the U.S. were examined for the presence of Clostridium -perfringens. Isolates were checked for the presence of the lecithinase gene (cpa) and enterotoxin genes (cpe) by PCR. Enterotoxin formation during sporulation was investigated using the Oxoid Toxin Detection Kit. Forty-three confirmed isolates (from 17% of total samples) were cpa-positive. Of those, 27 were cpe-positive. Together, levels of C. perfringens spores ranged from 3.6-2400/gm. The amount of enterotoxin in cell extracts ranged from 2-16 ng/ml. Some of the SEM images of isolated spore (# 78) and one plasmid-borne ent control (FD-153) showed an organized surface structure termed “candy-wrapper”. This extracellular structure remained after treatment with 0.1 % SDS for 1 hr, suggesting it was not composed of membrane debris from the mother cell. The D values of spores ranged from 1.19- 3.31 min. The addition of lysozyme in the plating medium elevated the recovery rate of heat-treated spores. The growth rate of a cocktail of spores from spices (# 31, # 32, # 45) between 4 to 5 hr after inoculation was determined with a doubling time of 6.82 min in hamburger. A cocktail of spores of plasmid-borne ent control showed an optimum growth rate between 5 to 8 hr after inoculation with doubling time of 15.98 min. However; spice isolate cocktail, plasmid-borne ent control cocktail (FD-5603 and FD-153), and a chromosome-borne ent control (NTCT 8239) were unable to germinate and outgrowth at 20oC. Inoculation in laboratory medium FTG indicated the same result as hamburger at 20oC. The ability of C. perfringens spores in spices to potentially survive cooking procedures can be followed by germination and growth of vegetative cells during improper cooling to levels associated with foodborne illness caused by this organism. Our results suggest that retail spices are potential vehicles of transmission of enterotoxin-positive C. perfringens.
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Determinação de isoflavonas e capacidade antioxidante de alimentos industrializados à base de soja e/ou produtos derivados consumidos no Brasil / Determination of isoflavones content and antioxidant capacity of industrialized foods containing soy and soy products consumed in BrazilAlezandro, Marcela Roquim 18 May 2009 (has links)
A soja contém alto conteúdo protéico e de lipídeos poliinsaturados e representa a principal fonte de isoflavonas. Por este grão não fazer parte da dieta brasileira, produtos contendo soja surgiram no mercado como fontes de isoflavonas, adaptados ao paladar da nossa população. Os condimentos também têm sido incorporados aos ditos \"alimentos funcionais\" pela sua relação com efeitos benéficos à saúde. Este trabalho objetivou determinar o teor de isoflavonas dos produtos contendo soja e/ou derivados, o teor de flavonóides de diferentes condimentos e marcas, e a capacidade antioxidante destas amostras. Os resultados mostram que o quibe vegetariano destaca-se como fonte de isoflavonas, e o chocolate pela capacidade antioxidante. Entre os condimentos, houve diferença significativa entre tipos e marcas. O orégano destacou-se quanto à capacidade antioxidante e a salsa quanto ao teor de flavonóides. Alimentos contendo soja ou derivados e os condimentos podem representar fontes de compostos bioativos para a população brasileira. / Soy contains high protein and polyunsaturated lipids content and represents the main source of isoflavones. This grain is not part of the Brazilian diet, so some products containing soy emerged as sources of isoflavones, adapted to the taste of our population. Spices have also been incorporated into \"functional foods\" by their relation to health benefits. This study aimed to determine the isoflavone content of products containing soy and/or derivatives, flavonoids content in different brands and condiments, and antioxidant capacity of these samples. The results showed that vegetarian \"quibe\" is a good source of isoflavones, and chocolate had the highest antioxidant capacity. Among spices, there were significant differences between the types and brands. Oregano had the highest antioxidant capacity and parsley had the highest flavonoids content. Foods containing soy or derivatives and condiments may represent sources of bioactive compounds for Brazilian population.
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Uso de ervas aromáticas na estabilidade oxidativa de filés de sardinha (Sardinella brasiliensis) processados / The use (ou effect) of herbs on oxidative stability of processed sardine (Sardinella brasiliensis) filletsPiedade, Karen Rother 14 September 2007 (has links)
Durante as últimas décadas a preocupação do consumidor em relação à qualidade dos alimentos cresceu consideravelmente, juntamente com a procura por alimentos funcionais ou componentes alimentares ativos fisiologicamente, também designados bioativos. Paralelamente objetiva-se a redução do emprego de produtos sintéticos em alimentos industrializados fortalecendo o apelo de que o alimento deve desempenhar funções terapêuticas e ainda não trazer riscos à saúde. Os peixes são alimentos que atendem bem a alguns desses requisitos já que possuem ácidos graxos poliinsaturados essenciais omega-3. A sardinha é um excelente exemplo. Em diversas investigações foi verificado que esses ácidos graxos têm um efeito cardioprotetor, além de estarem ligados à redução de susceptibilidade a tumores malignos. Muito se fala sobre a importância do aproveitamento de lipídeos de pescado e seus derivados para a alimentação humana, mas é necessário um balanço de ácidos graxos poliinsaturados na dieta assim como de antioxidantes que evitem a oxidação lipídica já que esta pode causar importantes danos biológicos, começando com o comprometimento desses componentes. A deterioração oxidativa dos lipídeos é uma das reações mais importantes e freqüentes nos alimentos onde estão presentes, inclusive nos peixes e isso tem determinado uma série de estudos ligados à ação dos radicais livres no organismo ou no alimento e principalmente sobre os agentes que neutralizam essas substâncias altamente reativas. Juntamente com a preferência do consumidor por produtos mais saudáveis pode ser notado um aumento do interesse pelo uso de antioxidantes naturais e de pesquisas nessa área. Na procura por alimentos mais saudáveis de uma maneira geral, o presente trabalho teve como objetivo trazer a sua contribuição ao conhecimento da funcionalidade das ervas como antioxidantes naturais. / During the last decades the consumer\'s concern in relation to the quality of the foods grew considerably. On those years the use of harmful components to the health was avoided as well as the search for functional foods or physiologically active components, also designated bioactives enhanced. Nowadays, the industry aims at a lesser use of synthetic products in foods. Therefore, food should carry through therapeutic functions and still not to present any risk to health. Fish attain these requirements well by furnishing the essential omega-3 polynsaturated fatty acids to the diet. Sardines are an excellent example. In several investigations it was verified that these fatty acids have a cardio-protector effect and they are related to malignant tumors incidence reduction. When administratin fish lipids to the diet, it is important to remember that a balance between polynsaturated fatty acids and antioxidants content is necessary in order to avoid lipid oxidation since it can cause important biological damages starting with the reduction of these essential lipids. Oxidative deterioration of lipids is one of the most important and frequent reactions presents in foods including fishes and has determined a series of studies linked to the free radicals behavior in the organism or in the food and to the identification of the agents that neutralize the highly reactive substances. Together with the consumer\'s preference for healthier products, an increase of the interest for the use of natural antioxidants can be observed as well as new researches in this area. In the search for healthier foods in a general way, the present work had as objective to contribute to the knowledge of the functionality of herbs as natural antioxidants.
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Detection and quantification of spice adulteration by near infrared hyperspectral imagingSeptember, Danwille Jacqwin Franco 03 1900 (has links)
Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Near infrared hyperspectral imaging (NIR HSI) in conjunction with multivariate image analysis was
evaluated for the detection of millet and buckwheat flour in ground black pepper. Additionally, midinfrared
(MIR) spectroscopy was used for the quantification of millet and buckwheat flour in ground
black pepper. These techniques were applied as they allow non-destructive, invasive and rapid
analysis.
Black pepper and adulterant (either millet or buckwheat flour) mixtures were made in 5% (w/w)
increments spanning the range 0-100% (w/w). The mixtures were transferred to eppendorf tube
holders and imaged with a sisuChema short wave infrared (SWIR) pushbroom imaging system
across the spectral range of 1000–2498 nm. Principal component analysis (PCA) was applied to
pseudo-absorbance images for the removal of unwanted data (e.g. background, shading effects
and bad pixels). PCA was subsequently applied to the ‘cleaned’ data. An adulterant concentration
related gradient was observed in principal component one (PC1) and a difference between black
pepper adulterated with buckwheat and millet was noted in PC4. Four absorption peaks (1461,
2241, 2303 and 2347 nm) were identified in the loading line plot of PC1 that are associated with
protein and oil. The loading line plot of PC4 revealed absorption peaks at 1955, 1999, 2136 and
2303 nm, that are related to protein and oil. Partial least squares discriminant analysis (PLS-DA)
was applied to NIR HSI images for discrimination between black pepper adulterated with varying
amounts of adulterant (millet or buckwheat). The model created with millet adulterated black
pepper samples had a classification accuracy of 77%; a classification accuracy of 70% was
obtained for the buckwheat adulterated black pepper samples.
An average spectrum was calculated for each sample in the NIR HSI images and the resultant
spectra were used for the quantification of adulterant (millet or buckwheat) in ground black pepper.
All samples were also analysed using an attenuated total reflectance (ATR) Fourier transform (FT)
– infrared (IR) instrument and MIR spectra were collected between 576 and 3999 cm-1. PLS
regression was employed. NIR based predictions (r2 = 0.99, RMSEP = 3.02% (w/w), PLS factor =
4) were more accurate than MIR based predictions (r2 = 0.56, RMSEP = 19.94% (w/w), PLS factors
= 7). Preprocessed NIR spectra revealed adulterant specific absorption bands (1743, 2112 and
2167 nm) whereas preprocessed MIR spectra revealed a buckwheat specific signal at 1574 cm-1.
NIR HSI has great promise for both the qualitative and quantitative analysis of powdered food
products. Our study signals the beginning of incorporating hyperspectral imaging in the analysis of
powdered food substances and results can be improved with advances in instrumental
development and better sample preparation. / AFRIKAANSE OPSOMMING: Die gebruik van naby infrarooi hiperspektrale beelding (NIR HB) tesame met veelvoudige
beeldanalise is ondersoek vir die opsporing van stysel-verwante produkte (giers en bokwiet) in
gemaalde swart pepper. Middel-infrarooi (MIR) spektroskopie is addisioneel gebruik vir die
kwantifisering van hierdie stysel-verwante produkte in swart pepper. Albei hierdie tegnieke is
toegepas aangesien dit deurdringend van aard is en dit bied nie-destruktiewe sowel as spoedige
analise.
Swart pepper en vervalsingsmiddel (giers of bokwiet) mengsels is uitgevoer in 5% (m/m)
inkremente tussen 0 en 100% (m/m). Eppendorfbuishouers is met die mengsels gevul en
hiperspektrale beelde is verkry deur die gebruik van ‘n sisuChema SWIR (kortgolf infrarooi)
kamera met ‘n spektrale reikwydte van 1000–2498 nm. Hoofkomponent-analise (HK) is toegepas
op pseudo-absorbansie beelde vir die verwydering van ongewenste data (bv. agtergrond, skadu en
dooie piksels). Hoofkomponent-analise is vervolgens toegepas op die ‘skoon’ data.
Hoofkomponent (HK) een (HK1) het die aanwesigheid van ‘n vervalsingsmiddel konsentrasie
verwante gradient getoon terwyl HK4 ‘n verskil getoon het tussen swart pepper vervals met giers
en bokwiet. Vier absorpsiepieke (1461, 2241, 2303 en 2347 nm) was geïdentifiseer binne die HK
lading stip van HK1 wat met proteïen en olie geassosieer kon word. Die HK lading stip van HK4
het absorpsipieke by 1955, 1999, 2136 en 2303 nm aangedui wat verband hou met proteïen en
olie. Parsiële kleinste waarde diskriminant-analise (PKW-DA) is toegepas op die hiperspektrale
beelde vir die moontlike onderskeiding tussen swart pepper vervals met verskeie hoeveelhede
vervalsingsmiddel (giers of bokwiet). ‘n Klassifikasie koers van 77% is verkry vir die model
ontwikkel met giers vervalsde swart pepper terwyl die model ontwikkel met bokwiet vervalsde
swarte pepper ‘n klassifikasie koers van 70% bereik het.
‘n Gemiddelde spektrum is bereken vir elke monster in die hiperspektrale beelde en die
resulterende spektra is gebruik vir die kwantifisering van vervalsingsmiddels (giers of bokwiet) in
gemaalde swart pepper. ‘n ATR FT-IR instrument met spektrale reikwydte van 576-3999 cm-1 is
additioneel gebruik vir die analise van alle monsters. Parsiële kleinste waarde regressie is gebruik
vir kwantifikasie doeleindes. NIR gebasseerde voorspellings (r2 = 0.99, RMSEP = 3.02% (m/m),
PLS faktore = 4) was meer akkuraat as die MIR gebasseerde voorspellings (r2 = 0.56, RMSEP =
19.94% (m/m), PLS faktore = 7). Vooraf behandelde NIR spektra het vervalsingsmiddel verwante
absorpsiepieke (1743, 2112 en 2167 nm) aangetoon terwyl vooraf behandelde MIR spektra ‘n
bokwiet verwante absorpsiepiek by 1574 cm-1 aangedui het.
NIR HB toon goeie potensiaal vir beide kwalitatiewe en kwantitatiewe analise van gepoeierde
voedsel produkte. Ons studie kan gesien word as die begin van die inkorporasie van
hiperspektrale beelding in die analise van gepoeierde voedsel material en verbeterde resulte kan
verkry word deur die vordering in instrumentasie ontwikkeling en verbeterde monstervoorbereiding.
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CONTROLE BOTÂNICO, FÍSICO-QUÍMICO E ATIVIDADE ANTI-INFLAMATÓRIA DE Glechon spathulata BENTH. (LAMIACEAE) / BOTHANIC, PHYSICO-CHEMICAL CONTROL AND ANTIINFLAMMATORY ACTIVITY OF Glechon spathulata BENTH. (LAMIACEAE)Banderó Filho, Vilmar Cláudio 13 July 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The quality of plant-derived drugs must be ensured through tests of authenticity (organoleptic features,
macro and microscopic identification), purity and integrity (foreign matter, total ash, acid insoluble ash, loss on
drying, microbiological contaminants and heavy metals) and also by qualitative and quantitative determinations of
active (s) principle (s) and / or chemical (s) marker (s) characteristic (s) of the species. Many plant species are
used in traditional medicine without scientific evidence of its pharmacological properties. The purpose of this work
lies in the botanical characterization, physico-chemical and anti-inflammatory activity of Glechon spathulata.
Among the macroscopic features of G. spathulata leaves stand out the spatulate form and subrevolute margin,
finely crenulate in the middle-upper. Microscopically, the uniseriate epidermis shows straight to slightly sinuous
cells, diacytic stomata, and non-glandular and glandular trichomes, dorsiventral mesophyll. Vascular bundles are
collateral closed, and no crystals were identified. These features help to the botanical quality control of G.
spathulata, and when analyzed in conjunction with its organoleptic properties, allow to ensure the authenticity of
the sample. Furthermore, the procedures which measure the extractives content, particle size, volatile oil content,
swelling index, bitterness and foaming index, and the chromatographic profile of crude ethanolic extract (CEE), its
fractions and essential oil by thin layer chromatography (TLC), allow to verify the authenticity besides to reveal
information about purity and integrity of this species. The chromatographic fingerprinting of CEE of G. spathulata
by high performance liquid chromatography (HPLC) was carried out in order to determine the nature of the main
compounds, and the presumptive identification of the flavonoids rutin and luteolin, also it allowed the verification
of the major compound rutin. Besides the authenticity of the extract obtained from aerial parts, the
chromatographic fingerprinting of G. spathulata enabled to monitor its quality and to characterize its phenolic
compounds. Therefore, the significant anti-inflammatory activity observed by the oral treatment with CEE of G.
spathulata in chronic inflammation in rats is probably exerted by polyphenolic compounds. The performed
analyses were based on techniques described in literature, official textbooks and Brazilian legislation and were
useful in establishing some parameters for the quality control of aerial parts of G. spathulata as raw material for
the pharmaceutical and / or food industries. / A qualidade dos derivados de drogas vegetais deve ser assegurada através de testes de autenticidade
(caracterização organoléptica, identificação macro e microscópica), pureza e integridade (matéria estranha,
cinzas totais, cinzas insolúveis em ácido, perda por dessecação, contaminantes microbiológicos e metais
pesados), e ainda por determinações qualitativa e quantitativa do (s) princípio (s) ativo (s) e/ou marcador (es)
químico (s) característico (s) da espécie. Muitas espécies vegetais são utilizadas na medicina tradicional sem
comprovação científica das suas propriedades farmacológicas. O objetivo deste trabalho reside na caracterização
botânica, físico-química e atividade anti-inflamatória de Glechon spathulata. Entre as características
macroscópicas das folhas de G. spathulata destacam-se a forma espatulada e a margem subrevoluta, crenada
no meio-superior. Microscopicamente, destacam-se a epiderme uniestratificada com células retas a pouco
sinuosas, estômatos diacíticos, tricomas tectores e glandulares, mesofilo dorsiventral, feixes vasculares do tipo
colateral fechado com bainha parenquimática, que na nervura central é incompleta e constituída por
esclerênquima, bem como a ausência de cristais. Estas características contribuem no controle botânico de
qualidade de G. spathulata, quando analisadas em conjunto com suas propriedades organolépticas, permitem a
autenticidade da amostra. Por outro lado, os teores extrativos, a granulometria, conteúdo de óleos voláteis,
índices de intumescência, amargor e espuma, bem como o perfil cromatográfico do extrato bruto (EB), suas
frações e do óleo essencial através da cromatografia em camada delgada (CCD), além de permitir a
autenticidade revelam informações sobre a pureza e integridade desta espécie. O perfil cromatográfico do EB de
G. spathulata estabelecido através da cromatografia líquida de alta eficiência (CLAE) permitiu determinar a
natureza dos principais compostos presentes, bem como a identificação presuntiva dos compostos flavonóides
rutina e luteolina, evidenciando como composto majoritário a rutina. Além da autenticidade do extrato obtido a
partir das partes aéreas, o perfil cromatográfico de G. spathulata permite monitorar a sua qualidade e caracterizar
os compostos fenólicos presentes, cujas ações farmacológicas são bem descritas na literatura. Desta forma, a
significativa atividade anti-inflamatória verificada pelo tratamento via oral com o EB de G. spathulata na
inflamação crônica em ratos, é provavelmente exercida pelos compostos polifenólicos presentes. As análises
realizadas basearam-se em técnicas descritas na literatura, em compêndios oficiais e na legislação brasileira, e
permitiram estabeler parâmetros úteis para o controle de qualidade das partes aéreas de G. spathulata como
matéria-prima para a indústria farmacêutica e/ou de alimentos.
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Determinação de isoflavonas e capacidade antioxidante de alimentos industrializados à base de soja e/ou produtos derivados consumidos no Brasil / Determination of isoflavones content and antioxidant capacity of industrialized foods containing soy and soy products consumed in BrazilMarcela Roquim Alezandro 18 May 2009 (has links)
A soja contém alto conteúdo protéico e de lipídeos poliinsaturados e representa a principal fonte de isoflavonas. Por este grão não fazer parte da dieta brasileira, produtos contendo soja surgiram no mercado como fontes de isoflavonas, adaptados ao paladar da nossa população. Os condimentos também têm sido incorporados aos ditos \"alimentos funcionais\" pela sua relação com efeitos benéficos à saúde. Este trabalho objetivou determinar o teor de isoflavonas dos produtos contendo soja e/ou derivados, o teor de flavonóides de diferentes condimentos e marcas, e a capacidade antioxidante destas amostras. Os resultados mostram que o quibe vegetariano destaca-se como fonte de isoflavonas, e o chocolate pela capacidade antioxidante. Entre os condimentos, houve diferença significativa entre tipos e marcas. O orégano destacou-se quanto à capacidade antioxidante e a salsa quanto ao teor de flavonóides. Alimentos contendo soja ou derivados e os condimentos podem representar fontes de compostos bioativos para a população brasileira. / Soy contains high protein and polyunsaturated lipids content and represents the main source of isoflavones. This grain is not part of the Brazilian diet, so some products containing soy emerged as sources of isoflavones, adapted to the taste of our population. Spices have also been incorporated into \"functional foods\" by their relation to health benefits. This study aimed to determine the isoflavone content of products containing soy and/or derivatives, flavonoids content in different brands and condiments, and antioxidant capacity of these samples. The results showed that vegetarian \"quibe\" is a good source of isoflavones, and chocolate had the highest antioxidant capacity. Among spices, there were significant differences between the types and brands. Oregano had the highest antioxidant capacity and parsley had the highest flavonoids content. Foods containing soy or derivatives and condiments may represent sources of bioactive compounds for Brazilian population.
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Uso de ervas aromáticas na estabilidade oxidativa de filés de sardinha (Sardinella brasiliensis) processados / The use (ou effect) of herbs on oxidative stability of processed sardine (Sardinella brasiliensis) filletsKaren Rother Piedade 14 September 2007 (has links)
Durante as últimas décadas a preocupação do consumidor em relação à qualidade dos alimentos cresceu consideravelmente, juntamente com a procura por alimentos funcionais ou componentes alimentares ativos fisiologicamente, também designados bioativos. Paralelamente objetiva-se a redução do emprego de produtos sintéticos em alimentos industrializados fortalecendo o apelo de que o alimento deve desempenhar funções terapêuticas e ainda não trazer riscos à saúde. Os peixes são alimentos que atendem bem a alguns desses requisitos já que possuem ácidos graxos poliinsaturados essenciais omega-3. A sardinha é um excelente exemplo. Em diversas investigações foi verificado que esses ácidos graxos têm um efeito cardioprotetor, além de estarem ligados à redução de susceptibilidade a tumores malignos. Muito se fala sobre a importância do aproveitamento de lipídeos de pescado e seus derivados para a alimentação humana, mas é necessário um balanço de ácidos graxos poliinsaturados na dieta assim como de antioxidantes que evitem a oxidação lipídica já que esta pode causar importantes danos biológicos, começando com o comprometimento desses componentes. A deterioração oxidativa dos lipídeos é uma das reações mais importantes e freqüentes nos alimentos onde estão presentes, inclusive nos peixes e isso tem determinado uma série de estudos ligados à ação dos radicais livres no organismo ou no alimento e principalmente sobre os agentes que neutralizam essas substâncias altamente reativas. Juntamente com a preferência do consumidor por produtos mais saudáveis pode ser notado um aumento do interesse pelo uso de antioxidantes naturais e de pesquisas nessa área. Na procura por alimentos mais saudáveis de uma maneira geral, o presente trabalho teve como objetivo trazer a sua contribuição ao conhecimento da funcionalidade das ervas como antioxidantes naturais. / During the last decades the consumer\'s concern in relation to the quality of the foods grew considerably. On those years the use of harmful components to the health was avoided as well as the search for functional foods or physiologically active components, also designated bioactives enhanced. Nowadays, the industry aims at a lesser use of synthetic products in foods. Therefore, food should carry through therapeutic functions and still not to present any risk to health. Fish attain these requirements well by furnishing the essential omega-3 polynsaturated fatty acids to the diet. Sardines are an excellent example. In several investigations it was verified that these fatty acids have a cardio-protector effect and they are related to malignant tumors incidence reduction. When administratin fish lipids to the diet, it is important to remember that a balance between polynsaturated fatty acids and antioxidants content is necessary in order to avoid lipid oxidation since it can cause important biological damages starting with the reduction of these essential lipids. Oxidative deterioration of lipids is one of the most important and frequent reactions presents in foods including fishes and has determined a series of studies linked to the free radicals behavior in the organism or in the food and to the identification of the agents that neutralize the highly reactive substances. Together with the consumer\'s preference for healthier products, an increase of the interest for the use of natural antioxidants can be observed as well as new researches in this area. In the search for healthier foods in a general way, the present work had as objective to contribute to the knowledge of the functionality of herbs as natural antioxidants.
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白藜蘆醇衍生物SRT1720在百草枯誘發帕金森氏症實驗模式的神經保護機制:針對粒線體功能之研究 / Investigating the protective mechanism of SRT1720 in mediating paraquat-induced Parkinson's disease model : focusing on mitochondrial function許庭凰, Hsu, Ting-Huang Unknown Date (has links)
帕金森氏症 (Parkinson’s disease,PD) 為目前最普遍的神經退化性疾病之一,該病因主要是由於中腦黑質區的多巴胺細胞的死亡造成運動系統的失能。環境常用農藥百草枯 (Paraquat,PQ) 目前已知是導致帕金森氏症的環境因子之一。它主要作用在粒線體上,阻斷粒線體的功能、造成大量氧化自由基生成、並誘導細胞凋亡的發生。沉默調節因子蛋白Sirtuin家族 (Sirtuin Family,Sirt1-Sirt7) 是一群 Nicotinamide adenine dinucleotide (NAD+) 依賴性去乙醯化酶,具有抗老化、以及預防神經退化性疾病等能力。SRT1720是根據天然植物酚類白藜蘆醇製造出來的化學衍生物,具有活化Sirtuin的能力。先前研究也顯示SRT1720具有增加糖尿病小鼠的存活率、抗腫瘤、抗發炎等功能,但SRT1720對於神經退化性疾病的保護性並不清楚。為了解SRT1720是否具有對抗PQ的細胞毒性,用以評估SRT1720是否具有治療帕金森氏症的潛力,本研究使用人類神經瘤母細胞株 (SH-SY5Y) 作為帕金森氏症的離體外實驗模式,來探討SRT1720及PQ對於細胞的作用及影響。實驗結果顯示,PQ造成細胞存活率呈劑量反應地下降,而SRT1720可以回復因PQ所造成細胞存活率的下降、細胞凋亡的產生、粒線體的型態變化,以及降低氧化自由基的生成等。這證明SRT1720對細胞具有神經保護的效果。本研究也利用西方點墨法證實了當細胞暴露在PQ下,SRT1720會回復因PQ所導致Sirt1-Sirt7蛋白含量的下降。其中,大量表現Sirt1可以對抗PQ造成細胞的死亡。本研究也發現SRT1720可回復PQ自噬小體在細胞中的堆積情形,利用西方點墨法觀察SRT1720可以回復LC3-I/II的蛋白質再細胞間的堆積。此外,在對於20週大的C57BL/6小鼠注射PQ (10 mg/kg) 及SRT1720 (0.1mg/kg或1 mg/kg),並利用滾輪及獨木橋試驗觀察其運動行為。結果顯示,SRT1720可以回復PQ所造成運動能力上的下降,並且減緩PQ所造成中腦區多巴胺神經元的傷害。綜觀以上結果,在細胞暴露在PQ時,SRT1720或許可以經由保護粒線體功能,使ROS生成量達到回復及降低細胞凋亡的發生。同時SRT1720也能保持自噬作用的平衡,降低自噬小體在細胞中的堆積。這些機轉也許與SRT1720可以保護多巴胺神經元有關。另一方面,由於Peroxisomal proliferator-activated receptor-coactivator 1α (PGC-1α) 與粒線體的生合成與神經保護有關,本實驗也發現SRT1720可改變PGC-1α去乙醯化的程度,但SRT1720對於Sirtuin蛋白以及Sirt1下游PGC-1α的活化與否還需做進一步的調查及研究。此研究顯示SRT1720對於保護細胞免於受到PQ所引發氧化壓力以及粒線體損傷之神經退化模型提供了一個具有潛力的治療方法。 / Parkinson’s disease (PD) is one of the most common neurodegenerative disorder and mainly affecting the motor system because of the dopamine neuronal death in the substantia nigra. The exposure to environmental neurotoxin paraquat (PQ) is a widely used herbicide. It induces the increase of ROS stress, leads to mitochondrial dysfunction, and results in apoptotic cell death. Epidemiologically, it could be the risk for PD incidence. Mammalian silent information regulator 2 Sirtuin Family (Sirt1-Sirt7) is a NAD+ dependent deacetylase enzyme and it protects against such as anti-aging and neurodegenerative disease. SRT1720 which derives from resveratrol is able to activate Sirt1. SRT1720 has been reported to improve survival in obese mice, anti-tumor, and anti-inflammatory, but the effect in the neurodegenerative disease it still unknown. We thus proposed if SRT1720 could have neuron- protective effect in PQ-induced toxicity. We used SH-SY5Y cell to evaluate the effect of SRT1720 and PQ. First, we confirmed that PQ could dose- and time-dependently decrease SH-SY5Y cell viability, increase ROS formation, and induce mitochondrial dysfunction. However, SRT1720 pretreatment improved cell viability, decreased apoptosis and ROS formation, and prevented mitochondrial dysfunction in PQ-treated SH-SY5Y cells. By Western blot analysis, SRT1720 pretreatment could preserve Sirt1-Sirt7 protein contents during PQ intoxication. In autophagy studies, we also found that SRT1720 could reduce PQ-induce autophagic vacuoles accumulation. Furthermore, we also found that intraperitoneally injection of 10 mg/kg PQ once a week in mice can decrease the level of motor activity after 6 weeks treatment. However, SRT1720 (0.1 mg/kg or 1mg/kg) treatment, reversed PQ- induced motor defect. Taken together, SRT1720 could protect mitochondrial function and improve cell survival during PQ intoxication. This work provided a promising therapeutic way for treating aging-related neurodegenerations, such as PD.
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Kan marinering av kött reducera uppkomsten av heterocykliska aminer vid tillagning? : En litteraturstudieLindh Dillon, Beatrice January 2019 (has links)
Bakgrund: Över 20 mutagena ämnen har detekterats i tillagade livsmedel. Till dessa räknas heterocykliska aminer. Studier har visat att dessa aminer kan orsaka mutationer och därmed öka risken för att utveckla cancer. Heterocykliska aminer bildas under tillagning av kött i höga temperaturer genom Maillardreaktionen. Syfte: Syftet med denna litteraturstudie var att se om marinering med öl, vin eller örtkryddor kan minska bildningen av heterocykliska aminer vid tillagning av kött. Metod: Denna studie är en litteraturstudie med ett urval av artiklar från databaserna PubMed och Web of Science. Totalt inkluderades 6 artiklar varav 3 artiklar studerade marinering med öl/vin och 3 studerade marinering med örtkryddor och örtextrakt. Resultat: Samtliga studier som undersöktes visade att marinering har en reducerande effekt på mängden heterocykliska aminer som bildas vid tillagning. Den mest troliga hypotesen om mekanismen är att effekten beror på den antioxidativa förmågan hos marinaderna. Ett exempel är en marinad med kombinationen gurkmeja och citrongräs som reducerade koncentrationen heterocykliska aminer med 94,8%. Slutsats: Marinering med öl, vin eller örtkryddor visades effektivt reducera mängden heterocykliska aminer. Stora reducerande effekter detekterades i marinader med gurkmeja, citrongräs, ingefära och mörk lager. Mer forskning behövs för att fastställa om reduktionen är kopplad till den antioxidativa effekten hos marinaderna / Background: Over 20 different mutagenic substances has been detected in cooked food. These include heterocyclic amines. Studies have shown that these amines can create mutations and increase the risk of developing cancer. Heterocyclic amines are formed in meat during the Maillard reaction which occours at high temperature cooking. Aim: The aim of this study was to investigate if the effect of marinating with beer, wine and herbs/spices can reduce the formation of heterocyclic amines found in cooked meat. Method: This study is a literature study with a selection of articles from databases PubMed and Web of Science. Six articles were included in this study. 3 articles involved marinade with beer/wine and 3 articles involved marinade with herbs/spices and extract. Results: All studies examined showed that marinating has a reducing effect on the concentration of heterocyclic amines formed during cooking. The most credible hypothesis of the mechanism is that the effect depends on the antioxidativ capacity of the marinades. For example one marinade with the combination of turmeric and lemon grass reduced the concentration of heterocyclic amines by 94,8%. Conclusion: Marinades containing beer, wine or herbs/spices was shown to effectively reduce the amount of heterocyclic amines. Great reducing effects were found using turmeric, lemon grass, ginger and black beer. More scientific research is needed to determine if the reduction is linked to the antioxidant effect in marinades.
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Screaming, flying, and laughing: magical feminism's witches in contemporary film, television, and novelsWells, Kimberly Ann 17 September 2007 (has links)
This project argues that there is a previously unnamed canon of literature called
Magical Feminism which exists across many current popular (even lowbrow) genres
such as science-fiction, fantasy, so-called realistic literature, and contemporary
television and film. I define Magical Feminism as a genre quite similar to Magical
Realism, but assert that its main political thrust is to model a feminist agency for its
readers. To define this genre, I closely-read the image of the female magic user as one
of the most important Magical Feminist metaphors. I argue that the female magic
userâÂÂcommonly called the witch, but also labeled priestess, mistress, shaman, mambo,
healer, midwifeâ is a metaphor for female unruliness and disruption to patriarchy and
as such, is usually portrayed as evil and deserving of punishment. I assert that many
(although not all) of the popular texts this genre includes are overlooked or ignored by
the academy, and thus, that an important focus for contemporary feminism is missed.
When the texts are noticed by parts of the academy, they are mostly considered popular
culture novelty acts, not serious political genres. As part of my argument, I analyze third wave feminismâÂÂs attempt to reconcile traits previously considered less than
feminist, such as the domestic. I also deconstruct the popular mediaâÂÂs negative
portrayal of contemporary feminism and the resulting reluctance for many young
women to identify themselves as feminist. I also argue that this reluctance goes hand in
hand with a growing attempt to seek new models for empowering female
epistemologies. My assertion is that these texts are the classrooms where many readers
learn their feminism. Finally, I list a short bibliography as a way of defining canon of
texts that should be considered Magical Feminist.
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