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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Baltymų frakcijų, praturtintų lektinais, išskirtų iš Urtica dioica L. žolės, antimutageninio, citotoksinio ir antioksidacinio aktyvumo tyrimas / Investigation of antimutagenic activity, cytotoxicity and antioxidant activity in lectin-enriched protein fractions from herb of Urtica dioica L

Staršelskytė, Rasa 30 June 2014 (has links)
R. Staršelskytės magistro baigiamasis darbas/ mokslinė vadovė prof. N. Savickienė; Konsultantės: dr. Annabella Vitalone, prof. Gabriela Mazzanti, dr. Antonella Di Sotto; Lietuvos sveikatos mokslų universiteto, Farmacijos fakulteto, Farmakognozijos katedra. – Kaunas. Romos universiteto La Sapienza, Fiziologijos ir farmakologijos katedra. – Roma. Darbo tikslas: baltymų frakcijų, praturtintų lektinais, išskirtų iš Urtica doica L. žolės, antimutageninio, citotoksinio ir antioksidacinio aktyvumo įvertinimas. Darbo uždaviniai: 1. Įvertinti Urtica dioica L. baltymų frakcijų įtaką Salmonella typhimurium ir Escherichia coli kamienų mutageniškumui, naudojant AMES testo metodą. 2. Ištirti Urtica dioica L. baltymų frakcijų citotoksiškumą HepG2 ląstelių proliferacijai, naudojant MTT dažo redukcijos reakcijos metodą. 3. Ištirti Urtica dioica L. baltymų frakcijų antioksidacinį aktyvumą, naudojant modelinius ABTS (2,2-azino-bis-(3-etilbenztiazolin-6-sulfono rūgšties)) ir superoksido radikalus. Metodai: 1. Lektinais praturtintų baltymų frakcijų antimutageniškumas tiriamas AMES testo metodu (grįžtamosios mutacijos modeliu in vitro) su S9 metabolinės aktyvacijos sistema (supernatantu iš žiurkių (paveiktų fenobarbitalio/β-naftoflavono mišiniu) kepenų lątelių mitochondrijų) ir be S9 metabolinės aktyvacijos sistemos. Eksperimentui naudojami trys bakterijų kamienai: S. typhimurium TA98, S. typhimurium TA100 ir E. coli WP2uvrA. 2. Citotoksiškumas nustatomas MTT dažo redukcijos reakcijos metodu... [toliau žr. visą tekstą] / Rasa Staršelskytė master thesis/ Supervisor of the research paper: prof. Nijolė Savickienė1 Consultants: PhD Annabella Vitalone, prof. Gabriela Mazzanti, PhD Antonella Di Sotto2 1Department of Pharmacognosy, Faculty of pharmacy, Lithuanian University of Health Sciences, Lithuania 2Department of Physiology and Pharmacology, Sapienza University of Rome, Italy Objective of work: evaluation of antimutagenicity, cytotoxicity and antioxidant activity of lectin-enriched protein fractions from herb of Urtica dioica L. Main tasks: 1. To evaluate antimutagenic activity of lectin-enriched protein fractions by bacterial reverse mutation assay. 2. To determine cytotoxicity of lectin-enriched protein fraction by the tetrazolium dye (MTT) colorimetric assay. 3. To evaluate antioxidant activity of lectin-enriched protein fraction against ABTS-free radical and superoxide-radical. Methods: 1. The antimutagenicity was studied in a bacterial reverse mutation assay (Ames test), both in the absence and presence of an exogenous metabolic activator S9 (the liver postmitochondrial supernatant of rats treated with the mixture phenobarbital/β-naphthoflavone to induce the hepatic microsomal enzymes). A set of three strains, S. typhimurium TA98, S. typhimurium TA100 and E. coli WP2uvrA, was used. 2. Cytotoxicity was determined by the tetrazolium dye (MTT) colorimetric assay in HepG2 human hepatoblastoma cell line. 3. The antioxidant activity was evaluated by ABTS-free radical scavenging activity test... [to full text]
2

Avaliaçãoda ação antimutagênica da Ipriflavonacontra os danos induzidos por ciclofosfamida

Delarmelina, Juliana Macedo 05 May 2012 (has links)
Made available in DSpace on 2016-12-23T13:49:05Z (GMT). No. of bitstreams: 1 Juliana Macedo.pdf: 1847907 bytes, checksum: 0c2c478111632f7e86372a5f0f6c8756 (MD5) Previous issue date: 2012-05-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Ipriflavone is a synthetic isoflavone derivative from daidzein and clinically prescribed for treating and preventing osteoporosis in postmenopausal women. We investigated the potential of this drug against the cytotoxic and mutagenic effects induced by cyclophosphamide (CPA) chemotherapy, using the micronucleus assay in bone marrow erythrocytes of Swiss albino mice (Mus musculus) in vivo. To evaluate their possible mechanisms of action, performed the evaluation of antioxidant activity by DPPH assay. For in vivo testing was carried out three protocols: pretreatment, simultaneous treatment and post treatment. The ipriflavone was evaluated in three different concentrations dissolved in DMSO (1,71; 8,57 e 42,85mg.kg-1 m.c) and administered by oral via. The bone marrow was collected for the evaluation of polycromatic erythrocytes (PCE) and the ratio PCE/(PCE+NCE) (polychromatic erythrocytes / polychromatic erythrocytes + normochromatic erythrocytes). For the DPPH test were assessed five concentrations of ipriflavone (500, 250, 150, 50 e 10μg.mLˉ¹) using DPPH solution (60μM). The results of in vivo tests show that the three concentrations of ipriflavone studied significantly reduced the frequency of MNPCEs induced by CPA, in the pre-treatment protocol and demonstrated the same effect at the concentrations of 1,71 e 42,85mg.kg-1 m.c in the post-treatment. However, simultaneous treatment did not reduce the frequency of MNPCE in any of the concentrations tested. In all protocols performed, the ratio PCE/(PCE+NCE) increased. There was variation between the genders in some of the experimental groups and the evaluation of antioxidant activity of ipriflavone showed no ability to donate hydrogens, suggesting that it acts through other mechanisms, such as inactivation of the enzyme activity of cytochrome P-450 / Ipriflavona é uma isoflavona sintética derivada da daidzeína e utilizada no tratamento e prevenção da osteoporose em mulheres pós-menopausadas. Investigamos o potencial dessa droga contra os efeitos citotóxico e mutagênico induzidos pelo quimioterápico ciclofosfamida (CPA), por meio do ensaio do micronúcleo em eritrócitos de medula óssea de camundongos albinos Swiss (Mus musculus) in vivo. Para avaliar um de seus possíveis mecanismos de ação realizamos a avaliação de sua atividade antioxidante pelo método de DPPH. Para os testes in vivo foram realizados três protocolos: pré-tratamento, tratamento simultâneo e pós-tratamento. A ipriflavona foi avaliada em três concentrações dissolvidas em DMSO (1,71; 8,57 e 42,85mg.kg-1 m.c) e administrada via oral. A medula óssea foi coletada para a avaliação dos eritrócitos policromáticos micronucleados (MNPCEs) e da razão PCE/(PCE+NCE) (eritrócitos policromáticos/eritrócitos policromáticos + eritrócitos normocromáticos). Para o teste de DPPH foram avaliadas 5 concentrações de ipriflavona (500, 250, 150, 50 e 10μg.mLˉ¹) utilizando solução de DPPH 60μM. Os resultados obtidos nos testes in vivo demonstram que a ipriflavona nas três concentrações pesquisadas reduziu significativamente a frequência de MNPCEs induzidos pela CPA no protocolo de pré-tratamento e demonstrou o mesmo efeito nas concentrações de 1,71 e 42,85mg.kg-1 m.c, no pós-tratamento. Entretanto, no tratamento simultâneo, ela não reduziu a frequência de MNPCE em nenhuma das concentrações testadas. Em todos os protocolos realizados houve o aumento da razão PCE/(PCE+NCE), demonstrando sua eficácia na redução da citotoxicidade induzida pela CPA. Houve variação entre os gêneros em alguns dos grupos experimentais. A avaliação da atividade antioxidante da ipriflavona revelou sua ausência de capacidade em doar hidrogênios para o radical DPPH, sugerindo que a mesma atua por meio de outros mecanismos, como por exemplo, inativação da atividade enzimática das isoenzimas do citocromo P-450
3

Atividades antimutagênica, antigenotóxica e anticitotóxica de Silybum marianum (L.) Gaertn e sua influência na expressão de genes de resposta a danos no DNA / Antimutagenic, antigenotoxic, and anticytotoxic activities of Silybum marianum (L.) Gaertn and its influence on gene expression responsive to DNA damage

Borges, Flavio Fernandes Veloso 26 March 2015 (has links)
Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-02-04T10:23:14Z No. of bitstreams: 2 Tese - Flavio Fernandes Veloso Borges - 2015.pdf: 2110689 bytes, checksum: 595ebd21ecf4f13568b0e3179e801f99 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-04T10:43:08Z (GMT) No. of bitstreams: 2 Tese - Flavio Fernandes Veloso Borges - 2015.pdf: 2110689 bytes, checksum: 595ebd21ecf4f13568b0e3179e801f99 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-04T10:43:08Z (GMT). No. of bitstreams: 2 Tese - Flavio Fernandes Veloso Borges - 2015.pdf: 2110689 bytes, checksum: 595ebd21ecf4f13568b0e3179e801f99 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Silymarin (SM) is a standardized extract from the seeds and leaves of milk thistle Silybum marianum (L.) Gaertn. It is composed mainly of flavonolignans, with silibinin (SB) being its principal active constituent. Known mainly as antioxidant and hepatoprotector, SM and SB were found to be clinically effective in the treatment of a variety of liver disorders, including acute and chronic viral hepatitis, toxin and drug-induced hepatitis and cirrhosis. Due to the wide biological activities presented by SM and SB, the present study aimed to evaluate their antimutagenic activities using the Ames mutagenicity test in Salmonella typhimurium, their antigenotoxic activities using the mouse bone marrow micronucleous test and the alkaline comet assay, and to assess their effect on the gene expression pattern of some genes associated with the process of carcinogenesis and chemoprevention. To assess antimutagenicity, bacterial suspensions of Salmonella typhimurium (TA98 and TA100 strains) were treated with different concentrations of SM or SB simultaneously with the appropriate positive controls for each strain. To assess antigenotoxicity, Swiss mice were orally treated with different concentrations of SM or SB simultaneously with a single intraperitoneal dose of mitomycin C (MMC) for the micronucleus test, and human blood lymphocytes were cotreated with SM or SB and methyl methanesulfonate (MMS) for the alcaline comet assay. To investigate the role of SM and SB in modulating gene expression, we conducted microarray analysis. The results showed that SM was not significantly effective in reducing the number of frameshift mutations in strain TA98, while SB demonstrated significant protection at higher doses (p < 0.05). Regarding strain TA 100, SM and SB significantly decreased mutagenicity (point mutations) (p < 0.05). The results of the antigenotoxic evaluation demonstrated that SM and SB significantly reduced the frequency of micronucleated polychromatic erythrocytes (MNPCE) (p < 0.05). The results also indicated that SM and SB significantly attenuated MMC induced cytotoxicity (p < 0.05). In the comet assay, SM and SB significantly reduced the genotoxicity of MMS (p < 0.05), with a stronger antigenotoxic activity exerted by the extract complex (SM) than the one exerted by the isolated main active constituent (SB). The expression array analysis of five genes related to DNA damage, carcinogenesis and/or chemoprevention mechanisms demonstrated an up-regulation of PTEN and BCL2, down-regulation of BAX and ABL1 and no significant change in ETV6 expression levels.In conclusion, our results demonstrated that both SM and SB presented antimutagenic and antigenotoxic actions, as well as modulated the expression levels of genes analysed under the experimental conditions of this study. / A silimarina (SM) é um extrato padronizado obtido a partir das sementes e folhas de Silybum marianum (L.) Gaertn. SM é composta principalmente de flavonóides, sendo a silibinina (SB) seu principal componente ativo. Conhecidas principalmente como antioxidantes e hepatoprotetoras, SM e SB foram consideradas clinicamente eficazes no tratamento de uma variedade de doenças do fígado, incluindo hepatites virais agudas e crônicas, hepatites induzidas por toxinas e/ou drogas e cirrose. Assim, devido à ampla gama de atividades biológicas apresentadas pela SM e SB, o presente estudo teve como objetivo avaliar suas atividades antimutagênicas utilizando o teste de Ames em Salmonella typhimurium, suas atividades antigenotóxicas pelo teste do micronúcleo em medula óssea de camundongos e pelo teste do cometa em linfócitos humanos e avaliar seus efeitos nos perfis de expressão gênica de alguns genes associados ao processo de carcinogênese e quimioprevenção. Para a avaliação da antimutagenicidade, suspensões bacterianas de Salmonella typhimurium (cepas TA98 e TA100) foram co-tratadas com diferentes concentrações de SM ou SB e os controles positivos adequados para cada cepa. Para a avaliação de antigenotoxidade, camundongos Swiss foram tratados oralmente com diferentes concentrações de SM ou SB concomitantemente a uma única dose intraperitoneal de mitomicina C (MMC) para o teste do micronúcleo, e linfócitos humanos foram tratados simultaneamente com SM ou SB e metil-metanossulfonato (MMS) para o ensaio do Cometa. Os resultados mostraram que a SM não foi significativamente efetiva em reduzir o número de mutações com deslocamento de quadro de leitura na cepa TA 98, enquanto que a SB apresentou uma proteção significativa nas doses maiores (p < 0.05). Em relação à cepa TA100, SM e SB reduziram significativamente a mutagenicidade (mudanças de pares de bases) (p < 0.05). Na avaliação de antigenotoxidade, SM e SB reduziram significativamente a frequência de eritrócitos policromáticos micronucleados (EPCMN) (p<0,05). Os resultados também mostraram que a citotoxicidade causada pela MMC foi significativamente atenuada pela SM e SB (p<0,05). No ensaio do cometa, SM e SB reduziram significativamente a genotoxicidade provocada pelo MMS (p<0.05), com uma atividade antigenotóxica maior exercida pelo extrato complexo (SM) do que pelo principal componente ativo isolado (SB). A análise dos níveis de expressão de cinco genes relacionados ao dano no DNA, mecanismos de carcinogênese e/ou quimioprevenção demonstrou um aumento na expressão de PTEN e BCL2, diminuição na expressão de BAX e ABL1 e ausência de mudança significativa nos níveis de expressão do ETV6. Com base nesses resultados, conclui-se que a SM e a SB apresentaram ações antimutagênicas e antigenotóxicas, e também modularam os níveis de expressão dos genes analisados sob as condições experimentais deste estudo.
4

Chemické a fyzikální transformace huminových kyselin / Chemical and Physical Transformations of Humic Acids

Vlčková, Zoja January 2009 (has links)
Tato práce představuje pilotní studii testující souvislosti mezi biologickými vlastnostmi a strukturou huminových kyselin extrahovaných z původního a modifikovaného jihomoravského lignitu, důl Mír, Mikulčice. V první části práce byly testovány metody vhodné ke zvýšení výtěžku huminových kyselin extrahovaných z lignitu. Oxidace lignitu v plynné fázi nepřinesla uspokojivé zvýšení výtěžku a byla instrumentálně poměrně náročná. Dále proto byla zkoumána jen oxidace v kapalné fázi a modifikace nízkomolekulárními organickými kyselinami. Modifikace organickými kyselinami byla inspirována procesy podporujícími biologické funkce v rizosféře, t.j. kořenový systém vylučuje exudáty způsobující změny v supramolekulové struktuře okolní organické hmoty čímž zlepšuje její mobilitu a prostupnost buněčnými stěnami. Primární struktura huminových kyselin připravených v této práci byla zkoumána prostřednictvím elementární analýzy a spektrálních metod (13C CPMAS NMR, EPR a UV-VIS spektroskopie). Navzdory tomu, že primární struktura vykazovala jen malé rozdíly, měření biologické aktivity a genotoxického potenciálu prokázalo, že huminové kyseliny a jejich humáty získané z lignitu s rozdílnou předúpravou vykazují odlišnou bioaktivitu. Proto byla dále zkoumána supramolekulární struktura vzorků ve zředěných roztocích, a to prostřednictvím vysokoúčinné vylučovací chromatografie, měření ultrazvukové rychlosti a hustoty. Testovány byly dva různé protionty – draselný a amonný. Získané výsledky potvrdily předpoklad, že pozorované změny v kvalitě humátů jsou závislé na protiiontu, koncentraci humátu v roztoku a také na metodě předúpravy původního lignitu. Obě zvolené metody předúpravy lignitu prokázaly svůj potenciál produkovat huminové kyseliny s rozmanitými biologickými vlastnostmi, aplikovatelné v zemědělství, životním prostředí a potenciálně i ve farmakologii.
5

Evaluation of phytochemical constituents and mutagenic properties of Coccinia rehmanni And Jatropha zeyheri Plant Extracts

Ndou, Nzumbululo 18 May 2019 (has links)
MSc (Microbiology) / Department of Microbiology / Background: The medicinal value of plants lies in some chemical substances that produce a definite physiological action in the human body. The secondary metabolites help the plants to survive hash conditions and could be used by humans as supplements of their health, as foods additives or for medicinal purposes. This bioactive compounds are not always beneficial to human beings, and some of this plants bioactive compounds can be toxic or genotoxic to human cells. This study used several methods to evaluate of phytochemical constituents and mutagenic properties of Coccinia rehmanni and Jatropha zeyheri plant extracts. Methodology: Methanol was used for extraction of the bioactive compounds from the two selected plants, filtered with Whatman filter paper and evaporated with rotary evaporator. The extracts were fractionated using open column chromatography. Chemical and TLC methods were used to determine phytochemicals of the study plants extracts and fractions. The plants extracts and fractions were tested against Vero cell lines in order to evaluate cytotoxicity and genotoxicity of the plants. NucRed and LTR Hoechst 33342 dyes were used for cytotoxicity and genotoxicity respectively. For the evaluation of cytotoxicity and genotoxicity Quantification of live and dead cells for the screening assay was performed using the ImageXpress Micro XLS Widefield Microscope and acquired images analyses using the MetaXpress software and Multi-Wavelength Cell Scoring Application Module. Antimutagenicity of plants extracts was observed using PARP universal colorimetric assay kit. Acquired data was transferred to an EXCEL spreadsheet and data was analyzed. Results and discussion: C. rehmanni (12.03%) yielded more extract than J. Zeyheri (8.20%). the two plants had different compound composition and were in different stages of maturity. The study revealed the domination of Terpenoids, Cardiac glycosides, Phenolic and tannis. With an exception of two fraction fractions all the fractions was found to be toxic to an extent were genotoxicity of such fraction could not be concluded. The reason for such extreme toxicity could be due to the influence of the retained alcohol during rotary evaporation. xvi | P a g e Conclusion: this study provides and add to existing knowledge on the phytochemicals mutagenicity and anti-mutagenicity of C. rehmanni and J. Zeyheri medicinal plants. The study serves as scientific proof that extensive use of this plant in traditional medicine for treatment of various ailments may lead to some irreversible damages. / NRF

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