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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

Characterizing Compensatory Effects of Silymarin on Gossypol Toxicosis in Lines of Chickens Divergently Selected for Humoral Immune Response

Blevins, Sarah 21 September 2009 (has links)
Feed costs are approximately 70% of total production cost for poultry producers. Poultry diets in the United States generally consist of 2 grains: corn and soybean meal. In recent years, the cost of these grains has dramatically increased. Due to these price increases, producers seek alternative feeds that provide adequate nutrition, and are also more affordable than "traditional" grains. Cottonseed meal is one alternative that is both affordable and an excellent source of crude protein. However, cottonseed meal contains gossypol, a pigment toxic to chickens. This study had two main objectives. The first objective was to determine if silymarin, an extract from milk thistle, could offset or prevent gossypol toxicosis. The second objective was to determine if divergent selection for humoral immune response would have an impact on the ability of the chicken to cope with gossypol toxicosis. Two preliminary studies were conducted. One determined basal activities of liver detoxification enzymes at various ages. The other determined concentrations of gossypol and silymarin that should be added to the diet to elicit a response. The information gathered from the second preliminary study was used to conduct the final experiment. In the final experiment, chickens from each of 2 lines selected for humoral immunity were exposed to diets containing gossypol, silymarin, gossypol and silymarin, and a control. Humoral immunity had no impact on the ability of the chicken to cope with gossypol toxicosis. Silymarin did not alleviate gossypol toxicosis. Future studies will focus on using a lower gossypol concentration in the diet. / Master of Science
2

Efeito protetor da silimarina sobre a esteato-hepatite nÃo alcoÃlica experimental induzida por irinotecano

Eudmar Marcolino de Assis JÃnior 15 September 2014 (has links)
O cÃncer coloretal (CRC) à a 3 neoplasia mais prevalente no mundo. O irinotecano (IRI), fÃrmaco de primeira linha para os tratamentos do CRC e sua metÃstase hepÃtica, tem aumentado a sobrevivÃncia dos pacientes. Contudo, seus efeitos colaterais, incluindo a esteato-hepatite nÃo alcoÃlica (NASH), podem limitar o curso do tratamento. Os protocolos baseados em irinotecano foram associados com um aumento no risco de NASH de 3,4 vezes. A silimarina (SIL) tem mostrado ser capaz de prevenir doenÃas do fÃgado gorduroso no contexto clÃnico e em modelos de danos hepÃticos induzidos quimicamente. Assim, nosso objetivo foi estudar o efeito da SIL na NASH induzida pelo IRI, assim como o mecanismo envolvido. MÃtodos e Resultados: Camundongos Swiss fÃmeas (n=8-10), foram divididos em 6 grupos e injetados com salina (SAL 5ml/kg i.p.), IRI (50 mg/kg i.p.), SIL (150 mg/kg v.o.) ou IRI (50 mg/kg i.p.) + SIL (SIL 1,5, 15, 150 mg/kg v.o.) 3x/semana/7 semanas. Amostras de sangue foram coletadas na sÃtima semana para determinar a concentraÃÃo sÃrica das enzimas hepÃticas ALT e AST (U/L). Animais foram mortos para a coleta do fÃgado para avaliar do dano tecidual (escores de Kleiner), dosagem de lipÃdeos totais (mg/g de tecido), MDA (nmol/g tecido), NPSH (mg de NPSH/g tecido), IL-6 (pg/mg de tecido), IL-10 (pg/mg de proteÃna) e IL-1&#946; (pg/mg de tecido), imunomarcaÃÃo de Ãxido nÃtrico sintase induzida (iNOS), 3-Nitrotirosina (Ntyr), e Receptor Toll Like tipo 4 (TLR4), quantificaÃÃo do fator nuclear kappa B (NF&#954;B) e da &#945;-actina de mÃsculo liso (&#945;-SMA) e expressÃo do gene RSS. ANOVA/Teste de Newman-Keuls ou Kruskal Wallis/ Teste de Dunn foram utilizados para anÃlise estatÃstica. Foram consideradas diferentes amostras onde o nÃvel descritivo era inferior a 5%. O trabalho foi aprovado pelo comità de Ãtica em pesquisa animal sob o nÃmero de protocolo: 21/12. O IRI aumentou de forma significante as transaminases hepÃticas, o infiltrado neutrofÃlico, o acÃmo de lipÃdeos, o acÃmulo de MDA, a expressÃo de NTyr, a expressÃo de &#945;-SMA, a expressÃo de NF&#954;B, a expressÃo de IL-1&#946;, a expressÃo de IL-6, a expressÃo de TLR4 e quantificaÃÃo de DNA bacteriano, quando comparados ao grupo SAL. SIL (1,5 mg/kg) melhorou esses parÃmetros, exceto a infiltraÃÃo neutrofÃlica e a quantificaÃÃo do DNA bacteriano quando comparados ao o grupo IRI (P<0,05). Por outro lado, a dose media de SIL (15 mg/kg) foi efetiva apenas no Infiltrado NeutrofÃlico, na expressÃo de NTyr, na expressÃo de NF&#954;B e na expressÃo de IL-6. Adicionalmente, essa dose aumentou a expressÃo hepÃtica de IL-10, a quantificaÃÃo de DNA bacteriano e a expressÃo da &#945;-SMA quando comparados com o grupo IRI (p<0,05). Contudo, a expressÃo de iNOS nÃo foi afetada pelo prÃ-tratamento com SIL (P<0,05) e a maior dose foi ainda mais deletÃria. ConclusÃes: O prÃ-tratamento com SIL previne o dano hepÃtico causado pelo IRI provavelmente atravÃs da mudanÃa da resposta inflamatÃria mediada por receptores TLR4 e citocinas IL-1, IL-6, IL-10 e NF&#954;B. O dano observado no grupo de animais tratados com as maiores doses de SIL parece ser dependente da translocaÃÃo bacteriana do intestido que à associada a ativaÃÃo do TLR4. Adicionalmente, a silimarina contribui para hepatoproteÃÃo por inibir o estresse oxidativo e a nitrosilaÃÃo proteica, prevenindo a ativaÃÃo de mecanismos de fibrose hepÃtica
3

Stanovení biologicky aktivních látek ve vybraných přírodních rostlinných extraktech / Analysis of some biologicaly active components in natural plant extracts

Kováčová, Ivana January 2016 (has links)
This thesis is focused on the study of the effectiveness of active ingredients from natural extracts such as milk thistle and turmeric. The thesis describes the use of modern methods of analysis and identification of active substances located in plants of milk thistle and turmeric. In the experimental part of thesis, which was preceded by a literature search focused on the biological effects of active substances in the chosen natural extracts, the extracts were characterized according to group characteristics (total assessment of polyphenols and flavonoids, assessment of antioxidant activity, and assessment of vitamin C volume and tocopherol). The next part is focused on the study of the encapsulation of natural active substances into the organic particles: liposomes. Silymarin and curcumin were encapsulated as active substances. The idea of a plant with a single active ingredient is usually erroneous. Plants usually contain hundreds of components which cooperate on a given effect. Therefore, the majority of herbalists believe that a simple plant is an active ingredient. However, some plants are known to be containing a particular active phytochemical. For instance, plants such as the milk thistle, turmeric, or a ginkgo are great examples of the plant containing a particular active phytochemical. In these cases, the active compound is disproportionately more effective than the plant itself. Encapsulation efficiency of active ingredients of Silymarin and curcumin was determined by HPLC/PDA. The aim of the analysis was to observe the behavior of elements during the incubation in surrounding of gastric juice model, and the stability while maintaining the particles in model food.
4

Vliv ostropestřce mariánského (Silybum marianum L.) na zdravotní ukazatele laboratorních potkanů

Pražáková, Jana January 2018 (has links)
The aim of this thesis is to evaluate the influence of the seeds cakes of milk thistle (Silybum marianum L.) into feed fodder of laboratory rats. Milk thistle is one of the most famous and most frequently used herb positively influencing liver function. The aim was to verify the hypothesis that the seeds cakes of milk thistle in the feed fodder have influence on the biochemical parameters of blood. There were 24 male laboratory rats of Wistar albino species separated into 2 groups (A, B). Rats in the group A were fed with feed fodder with additional 10% of milk thistle seeds cakes. The control group (B) was fed with feed fodder without any additional milk thistle seeds cakes. The content of silimarin in the seeds cakes was 26,5mg/g. During the 30 days experiment average weight increase and biochemical values of blood was observed. Weight was measured on the 0. - 7. - 14. - 21. – 30. day of the experiment. Blood measurements were conducted by heart punction after killing 3 laboratory rats by inhalative anesthesia of Isofuran on 0. - 10. - 20. - 30. day of the experiment. The full blood sample was collected to determine biochemical blood parameters. There was no significant influence of milk thistle seeds cakes on the biochemical parameters of blood. Group fed with milk thistle seeds cakes showed higher activity of AST enzymes as well as higher concentration of HDL laboratory rats fed with milk thistle seeds cakes. Laboratory rats fed with milk thistle seeds cakes showed higher increase in daily weight measurements than the group of control. Results show that milk thistle seeds cakes have no significant influence on health indicators taken from the biochemical parameters of the blood.
5

Kardiovaskulární účinky silymarinu / Cardiovascular effects of silymarin

Ryzová, Leona January 2020 (has links)
1 ABSTRACT Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Leona Ryzová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Cardiovascular effects of silymarin Aim: The aim of the diploma thesis is to summarize the existing knowledge about the mixture of natural plant substances collectively referred to as silymarin and to map the results of the latest studies focusing on the cardiovascular effects of silymarin. Main findings: Available data suggest that silymarin has positive effects on the human body, including hepatoprotective, choleretic and cholagogic, neuroprotective, anticancer and antiviral, anti-inflammatory and positive effects on diabetes mellitus. Positive effects on the cardiovascular system include protective effects on the vascular endothelium, antioxidant effects, beneficial effects on blood lipids, regulation of blood aggregation and antidiabetic effects. Although the conclusions from cardiovascular studies are not always the same, most confirm the positive effect of silymarin on the cardiovascular system. A necessary part of future research will be the search for new dosage forms in order to increase the bioavailability of silymarin, which so far limits its clinical application. Conclusion: Silymarin is a mixture of...
6

Účinky vybraných flavonolygnanů silymarinu ex vivo na izolované aortě potkana / The ex vivo effects of selected silymarin flavonolygnans on isolated rat aorta

Sloukgi, Tatiana January 2020 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Tatiana Sloukgi Supervisor: PharmDr. Jana Pourová, Ph.D. Title of Diploma Thesis: The effect of Silymarin Flavonolignans and their sulfated conjugates on blood vessels ex vivo. Silymarin flavonolignans have recently shown some positive effects on the cardiovascular system. In this work, we studied the vasodilatory effect on rat aorta ex vivo of three silymarin conjugates, silybin A-20-sulfate, silybin B-20-sulfate and 2,3- dehydrosilychristin-19-O-sulfate, and one parent flavonolignan 2,3- dehydrosilychristin. For each substance, a concentration response curve was created and the concentration that produces 50% of maximum relaxation was determined (EC50). All substances exerted very low or no vasodilatory activity. Finally, we focused on the mechanism of action of silybin A. We tested whether its vasorelaxant activity depends on the presence of intact endothelium. The vasorelaxant effect of silybin A on isolated rat aorta ex vivo was clearly endothelium-dependent.
7

Vliv silymarinu, naringinu a resveratrolu na jaterní poškození vyvolané vybranými xenobiotiky / The effect of silymarin, naringin and resveratrol on the liver damage induced by some xenobiotics

Kovaříková, Pavla January 2015 (has links)
The vast majority of exogenous substances is metabolized in the liver. In the course of the biotransformation, partly biologically non-active products, partly reactive species leading to cell structure injury and even to the liver failure are produced. Oxidative stress plays a significant role in the toxic- and drug-induced liver damage. Endogenous and exogenous antioxidants contribute to equilibrium between the production and the elimination of reactive oxygen species and thus prevent the oxidative stress. In acute experiments in rats we examined the ability of natural antioxidants silymarin, naringin and resveratrol and of synthetic chelator deferipron to protect against liver damage induced by paracetamol, thioacetamide and tamoxifen. The following parameters of oxidative stress were measured in the liver homogenates: level of lipid peroxidation (LP), concentration of reduced glutathione (GSH), activities of glutathione peroxidase (GPx) and of catalase (CAT); in some cases the iron liver content. The following markers of liver damage were measured in serum: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH). Concernig markers of oxidative status, silymarin exerted the most efficient antioxidant properties amelioratig the TAA- and TAM-induced lipid...
8

Stanovení stechiometrie komplexů dehydrosilybinu A s mědí / Determination of the stoichiometry of the copper complexes with dehydrosilybine A

Klimková, Kateřina January 2019 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Kateřina Klimková Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm. D., Ph.D. Consultant: Assoc. Prof. Kateřina Valentová, Ph.D. Title of Thesis: Determination of the stoichiometry of the copper complexes with dehydrosilybin A Silymarin, the standardized extract of the milk thistle (Silybum marianum), is a widely used approved over-the-counter drug that is recommended for a number of liver diseases. Silymarin contains as one of its components 2,3-dehydrosilybinA, which has an appropriate metal binding site in its structure. In general, flavonolignans, due to their structure, can interact with transition metals in the gastrointestinal tract by forming complexes. This property can be useful for the protection against excessive amounts of metals in the body. The aim of this in vitro study was to analyse the interaction of 2,3-dehydrosilybin A with copper, which plays a crucial role in the organism as a cofactor of many enzymes. Although being an essential element, it can, however, be toxic at elevated levels. Stoichiometry, as one of the most important characteristics of the complex, was determined by UV-Vis spectrophotometry in four (patho)physiological pH conditions (4.5; 5.5; 6.8; 7.5)...
9

Vliv silymarinu, naringinu a resveratrolu na jaterní poškození vyvolané vybranými xenobiotiky / The effect of silymarin, naringin and resveratrol on the liver damage induced by some xenobiotics

Kovaříková, Pavla January 2015 (has links)
The vast majority of exogenous substances is metabolized in the liver. In the course of the biotransformation, partly biologically non-active products, partly reactive species leading to cell structure injury and even to the liver failure are produced. Oxidative stress plays a significant role in the toxic- and drug-induced liver damage. Endogenous and exogenous antioxidants contribute to equilibrium between the production and the elimination of reactive oxygen species and thus prevent the oxidative stress. In acute experiments in rats we examined the ability of natural antioxidants silymarin, naringin and resveratrol and of synthetic chelator deferipron to protect against liver damage induced by paracetamol, thioacetamide and tamoxifen. The following parameters of oxidative stress were measured in the liver homogenates: level of lipid peroxidation (LP), concentration of reduced glutathione (GSH), activities of glutathione peroxidase (GPx) and of catalase (CAT); in some cases the iron liver content. The following markers of liver damage were measured in serum: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH). Concernig markers of oxidative status, silymarin exerted the most efficient antioxidant properties amelioratig the TAA- and TAM-induced lipid...
10

Technologie pěstování ostropestřece mariánského (Silybum marianum) ve vztahu ke kvalitě produktu a jeho zpracování / Cultivation Technology of Milk Thistle (Silybum Marianum)in Relation to the Product Quality and its Processing

GRAMANOVÁ, Hana January 2009 (has links)
Silybum marianum has been a plant known for millenniums thanks to its pharmacological effects especially in fields of liver, gallbladder or even colon cancer treatment. A complex of effective components is called silymarin. Its amount and structure in milk thistle seeds are very important. That{\crq}s why there{\crq}s a tendency to develop methods which could increase silymarin quantity together with silymarin quality in this herb. This was also the aim of this thesis. One of the possibilities to level up the content of effective components in drugs is to bring this plant in stress. There were realized two ground-plot experiments. The stress agens was acetatonsalicylic acid (ASA) of different concentrations applicated on leaves of these plants, concretely in the concentrations of 10-5 mol.l-1, 10-4 mol.l-1, 10-3 mol.l-1. In the case of the application ASA concentration 10-3 mol.l-1 there was proved an effective action. The increase of effective components in seeds reached approximately 116,5 % ratio compared with control application of distilled water on the Silybum marianum leaves. The silymarin complex was determined by High Performance Liquid Chromatography. The preparation of the extract was practised in different ways {--} using ethyl alcohol extract and distilled water in combination with various temperatures of extracts storage. These methods were compared one another. As the best one has been turned out to be using 60% ethanol concentration for the duration of 96 hours in the storage temperature 20°C.

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