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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.
31

Johannesört – effektiv behandling vid infektioner? : Medicinalväxten Hypericum perforatum L. och dess antibakteriella aktivitet mot multiresistenta Staphylococcus aureus

Carlsson, Amelie January 2023 (has links)
Antibiotic resistance is a rapidly increasing and serious global problem, with infectious diseases currently being the second leading cause of death worldwide. The World Health Organization (WHO) has estimated that 700,000 people worldwide die each year as a result of antibiotic resistance, and this number is projected to rise to 10 million per year by 2050 if no action is taken. This makes it vital to find new antibacterial agents to treat infectious diseases. Staphylococcus aureus (S. aureus) is a commonly occurring gram-positive bacterium from the genus Staphylococcus. The bacterium can cause several diverse types of infectious diseases, ranging from mild to life-threatening. Hypericum perforatum L. (H. perforatum) is a plant that has been used as a medicine in various preparations for thousands of years to treat different conditions, such as e.g., wound healing. Recent investigations have shown an antibacterial effect of the plant against the bacterium S. aureus, this suggested that H. perforatum may have a possible antimicrobial effect and could potentially be used in the treatment of certain infections. The purpose of this literature review was to investigate the in vitro antibacterial effect of H. perforatum against S. aureus. For this work, database searches were conducted in PubMed and SciFinder, and four studies were finally selected that examined the in vitro effect of H. perforatum against S. aureus. Common for all the studies was that they used the broth dilution method in their analyses to obtain MIC values. The results of the literature reviews showed that H. perforatum inhibited non-resistant isolates of S. aureus with MIC values between 0.01 – 950 µg/ml. For the resistant isolates evaluated, MIC values were between 0.01 – 0.02 µg/ml. The MIC-value against the multidrug resistant strain MDR-BAA 44 was 0.01 µg/ml. The other studies had higher MIC values and less activity compared to the results reported in the first study. The first study also showed that H. perforatum had better activity against all isolates than the positive controls tetracycline and penicillin. Further studies are needed to ensure and validate the results shown in study one. Also, research should focus on further studying the effect in vivo in larger studies than previously conducted. In addition, evaluation whether a synergistic effect against resistant S. aureus can be achieved through the combination of H. perforatum together with another plant species or with an antibiotic that could provide an alternative treatment of serious infections. / Infektionssjukdomar är idag den näst vanligaste dödsorsaken i världen och Världshälsoorganisationen (WHO) har beräknat att 700 000 personer i världen dör varje år till följd av antibiotikaresistens. Denna siffra kommer att stiga snabbt till 10 miljoner per år till år 2050 om inte åtgärder tas för att förhindra fortsatt spridning. Antibiotikaresistens är ett snabbt ökande och allvarligt globalt problem. Detta gör det livsnödvändigt att hitta nya antibakteriella medel för att kunna behandla infektionssjukdomar. Hypericum perforatum L. (H. perforatum) är en växt som i tusentals år använts som läkemedel iolika beredningar och för olika åkommor, som till exempel sårläkning. Antibakteriell effekt av växten har kunnat identifierats mot bakterien Staphylococcus aureus (S. aureus). S. aureus är en vanligt förekommande gram-positiv bakterie. Bakterien orsakar flera olika typer av infektionssjukdomar som kan vara allt från milda till livshotande. H. perforatum innehåller substanser med antibakteriell effekt som kan användas vid behandling av vissa infektionssjukdomar.  Syftet med denna studie var att undersöka den antibakteriella effekten in vitro av H. perforatum mot S. aureus. För detta litteraturarbete gjordes databassökningar i PubMed och SciFinder av tidigare publicerade studier. Fyra studier valdes slutligen ut som uppfyllde inklusionskriterierna. Samtliga studerade in vitro effekten av H. perforatum mot S. aureus. Samtliga studier använde sig av buljongspädningsmetoden i sina analyser där MIC-värden erhölls.  Resultaten från studierna visade att H. perforatum inhiberade icke-resistenta isolat av S. aureus med MIC-värden mellan 0,01 – 950 µg/ml. För de resistenta isolat som testades blev MIC-värden 0,01 – 0,02 µg/ml. MIC-värdet mot den multi-resistenta bakterien MDR-BAA 44 var 0.01 µg/ml. De andra studierna rapporterade högre MIC-värden jämfört med studie 1. Denna studie visade även att H. perforatum hade bättre aktivitet mot samtliga isolat än de positiva kontrollerna, tetracyklin samt penicillin. Vidare behöver fler studier genomföras för att säkerställa de resultat som studie 1 visade. Nya studier behöver också utvärdera om synergistisk effekt mot resistenta S. aureus kan uppnås vid kombination av H. perforatum och en annan växtart eller antibiotikum som kan leda till nya behandlingsalternativ av svåra infektioner.
32

Compara??o de efeitos dos extratos de Hypericum perforatum (Hip?rico) e de Mentha crispa (Hortel?) em diferentes modelos experiemtais

Santos Filho, Sebasti?o David dos 16 August 2007 (has links)
Made available in DSpace on 2014-12-17T14:13:22Z (GMT). No. of bitstreams: 1 SebastiaoDSF.pdf: 475002 bytes, checksum: d28adb2821adc67501d7e19f42e9b6a3 (MD5) Previous issue date: 2007-08-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Several clinic evaluations have been possible with radiobiocomplexes labeled with technetium-99m (99mTc). Some natural and synthetic drugs are capable of to interfere on the labeling of blood constituents with 99mTc, as well as on the biodistribution of radiobiocomplexes. Authors have also reported about the toxicity of several natural products. The aim of this study was to compare the effects of the Mentha crispa (hortel?) and of the Hypericum perforatum (hip?rico) in different experimental models. On the labeling of red blood cells (RBC) and plasma and cellular proteins with 99mTc, both extracts were capable of to decrease the radioactivity percentage on the cellular compartment and on the fixation on plasma and cellular proteins. On the morphometry of the RBC, only the hortel? was capable to alter the shape and the perimeter/area ratio of the RBC. On the biodistribution of the radiobiocomplex sodium pertechnetate (Na99mTcO4), the hortel? increased the Na99mTcO4 distribution in the kidney, spleen, liver and thyroid, meanwhile the hip?rico decreased the Na99mTcO4 distribution in the bone, stomach, lungs and thyroid, and increased the Na99mTcO4 distribution in the pancreas. On the bacterial cultures survival, the hip?rico was capable of to protect the bacteria against the stannous chloride (SnCl2) effect. The hip?rico did not alter the topology of plasmidial DNA and did not protect the plasmidial DNA against the SnCl2 action. Probably, the effects presented by both extracts could be due to chemical compounds of the extracts that could alter the morphology of the RBC and the plasma membrane ions transport, and/or by phytocomplexes that could be formed with different effects dependent on the biological system considered / Avalia??es cl?nicas t?m sido poss?veis com radiobiocomplexos marcados com tecn?cio-99mTc (99mTc). Drogas naturais ou sint?ticas s?o capazes de interferir na marca??o de estruturas sangu?neas com 99mTc, assim como na biodistribui??o de radiobiocomplexos. Tamb?m tem sido descrita a toxicidade de v?rios produtos naturais. O objetivo deste estudo foi comparar o efeito dos extratos de Mentha crispa (hortel?) e de Hypericum perfloratum (hip?rico) em diferentes modelos experimentais. Na marca??o de estruturas sang??neas com 99mTc verificou-se que ambos os extratos foram capazes de diminuir a radioatividade no compartimento celular, nas prote?nas plasm?ticas e celulares. Na morfometria das hem?cias, apenas a hortel? foi capaz de alterar a forma e a rela??o per?metro/?reas das hem?cias. Na biodistribui??o do radiobiocomplexo pertecnetato de s?dio (Na99mTcO4) a hortel? aumentou a capta??o do Na99mTcO4 no rim, no ba?o, no f?gado e na tire?ide, enquanto que o hip?rico diminuiu a capta??o do Na99mTcO4 no osso, no est?mago, no pulm?o e na tire?ide, e aumentou no p?ncreas. Na sobreviv?ncia de culturas bacterianas o hip?rico foi capaz de proteger a bact?ria do efeito danoso do cloreto estanoso (SnCl2). O hip?rico n?o alterou a topologia nem protegeu o DNA plasmidial da a??o do SnCl2. Provavelmente os efeitos apresentados por ambos os extratos poderiam ser explicados por subst?ncias presentes nos extratos que poderiam alterar a morfologia das hem?cias, o transporte de ?ons pela membrana e/ou formar fitocomplexos. O estudo teve car?ter multidisciplinar com a participa??o das seguintes ?reas do conhecimento: Radiobiologia, Bot?nica, Endocrinologia, Fitoterapia e Hematologia
33

An examination of neuroprotective effects of 17B-estradiol and extracts from Panax Quinquefolius L., Ginkgo Biloba and HypericumPerforatum against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)induced nigral-striatal neuronal degeneration

Chan, Wing-yan, Veronica, 陳詠恩 January 2001 (has links)
published_or_final_version / Anatomy / Master / Master of Philosophy
34

EFEITO DO Hypericum perforatum EM DIFERENTES MODELOS DE DESORDENS MOTORAS EM RATOS / EFFECT OF Hypericum perforatum ON DIFFERENT MODELS OF MOVEMENT DISORDERS IN RATS

Reis, Elizete de Moraes 26 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Abnormal movements are clinical symptoms present in neurodegenerative diseases, such Parkinsonism , as well as Tardive dyskinesia. It is thought that unbalance in monoamine levels with their consequent metabolism could be involved in the etiology of these abnormal movements. However, until this moment there is not efficacious treatment with low side effects for these conditions. In this context, Hypericum perforatum (H. perforatum), popularly known as St. John s Wort, is a plant largely used as antidepressant and presenting high amount of polyphenol constituents. Its antidepressant mechanism seems to involve the increase of monoamines and monoaminoxidase inhibition. Here, we evaluated the effect of H. perforatum on different models of abnormal movements in rats, either using fluphenazine or reserpine. It were quantified the number of vacuous chewing movements (VCMs) and locomotor activity (number or rearings and crossings) in both models. In experiment 1, rats received a single administration of fluphenazine enantate (25 mg/Kg, i.m.) and/or H. perforatum (300 mg/Kg, in place of drinking water) during 7 days. Fluphenazine treatment increased VCMs and decreased the locomotor activity after 7 days of treatment. However, H. perforatum did not alter either the number of VCMs or the locomotor activity (represented by number of crossing and rearing in the open field test) in rats. In experiment 2, rats received reserpine administration once a day during 3 days (0.5 mg/Kg, s.c.) and/or H. perforatum (300 mg/Kg, in place of drinking water) during 16 days. Reserpine treatment increased VCMs and decreased the locomotor activity. H. perforatum did not alter the number of VCMs or the number of rearing. However, H. perforatum co-treatment could avoid the effect of reserpine on number of crossings. In conclusion, H. perforatum did not seem to be efficacious to protect against orofacial movements induced by fluphenazine or reserpine in rats. / As desordens motoras são sintomas de doenças neurodegenerativas bem como podem estar associadas ao tratamento com antipsicóticos. Cita-se como exemplo destas desordens, sintomas da Doença de Parkinson (DP) e a Discinesia Tardia (DT), respectivamente. O desequilíbrio cerebral nos níveis de monoaminas e, consequentemente, seu metabolismo tem sido relacionados ao desenvolvimento dos movimentos anormais que aparecem nas desordens motoras, tendo em vista que os circuitos dopaminérgicos estão envolvidos na gênese da DP e da DT. No entanto, ainda não existem tratamentos eficazes e com poucos efeitos colaterais para tais condições. A Hypericum perforatum (H. perforatum), popularmente conhecido como Erva de São João, consiste numa planta amplamente utilizada como antidepressiva e que possui uma grande quantidade de compostos fenólicos, cujo mecanismo para esta atividade está relacionado à inibição da monoamina oxidade (MAO) e da recaptação de monoaminas cerebrais. Assim, o objetivo do presente estudo foi investigar o efeito do H. perforatum em modelos de desordem motora induzida por flufenazina ou reserpina em ratos. Foram quantificados os movimentos de mascar no vazio (MMV) e atividade locomotora (cruzamentos e levantadas observados no teste de campo aberto) em ambos os modelos. No experimento 1, os ratos receberam uma única administração de enantato de flufenazina (25 mg/Kg, i.m.) e ou H. perforatum (300 mg/Kg, no lugar da água de beber) durante 7 dias. O tratamento com flufenazina aumentou o número de MMVs e diminuiu a atividade locomotora em ratos após 7 dias de tratamento. No entanto, o tratamento com H. perforatum não protegeu das alterações comportamentais causadas pelo tratamento com flufenazina. No experimento 2, os ratos receberam água ou H. perforatum (300 mg/Kg, no lugar da água de beber) durante 16 dias. A partir do dia 9 de tratamento os animais receberam uma administração diária de reserpina (0,5 mg/Kg, s.c.) ou veículo durante 3 dias com intervalo de 48 horas. A reserpina aumentou o número MMVs e diminuiu a atividade locomotora em campo aberto. O prétratamento com H. perforatum não alterou o efeito da reserpina sobre o número de MMVs e levantadas. Porém, o pré-tratamento com H. perforatum preveniu o efeito da reserpina sobre número de cruzamentos. Desta forma, podemos concluir que o H. perforatum não apresentou efeito benéfico sobre os movimentos orofaciais induzidos por flufenazina ou reserpina em ratos.
35

Paprastosios ir keturbriaunės jonažolių azoto ir sunkiųjų metalų koncentracijos ypatumai / Nitrogen and heavy metals concentration‘s peculiarities in Hypericum perforatum L. and Hypericum maculatum Crantz

Ramonaitė, Kristina 15 June 2009 (has links)
Magistro darbe tiriama paprastosios ir keturbriaunės jonažolių azoto ir sunkiųjų metalų koncentracijos ypatumai. / Master degree work cover the studies of nitrogen and heavy metals concentration‘s peculiarities in Hypericum perforatum L. and Hypericum maculatum Crantz.
36

Avaliação dos aspectos toxicológicos dos fitoterápicos: um estudo comparativo / Evaluation of toxicological aspects of the herbal medicines:a comparative study

Turolla, Monica Silva dos Reis 13 April 2004 (has links)
Esta Dissertação apresenta informações gerais sobre os medicamentos fitoterápicos e os aspectos toxicológicos de uma amostra de dez plantas medicinais comercializadas como medicamentos fitoterápicos no Brasil, pesquisados junto aos principais bancos de dados e fontes públicas de informação. A análise dos medicamentos fitoterápicos cobre as dimensões histórica, econômica e farmacêutica. No tocante aos aspectos toxicológicos, foram avaliados os dados de toxicidade pré-clínica de dez plantas selecionadas, e realizado um levantamento das informações publicadas para Hypericum perforatum e Piper methysticum, relacionadas ao termo toxicidade, segundo três importantes bancos de dados. Adicionalmente, este trabalho aborda as propostas para realização de ensaios de toxicidade pré-clínica para os fitoterápicos segundo a OMS e legislação brasileira, e as normas para avaliação de substâncias químicas segundo a OECD. / This thesis presents general information on herbal medicines and on the toxicological aspects of a sample of ten medicinal plants traded as herbal medicines in Brazil. The survey was carried out in the main databases and public sources of information. The analysis on the herbal medicines encompasses the historical, economic and pharmaceutical dimensions. In what concerns toxicological aspects, data on pre-clinical toxicity were evaluated for Hypericum perforatum and Piper methysticum, these keywords being related to toxicity in three important databases. In addition, this study discusses the proposals for pre-clinical toxicity trials on herbal medicines according to WHO and the Brazilian legislation, and the standards for evaluation of chemical substances according to OECD.
37

Avaliação dos aspectos toxicológicos dos fitoterápicos: um estudo comparativo / Evaluation of toxicological aspects of the herbal medicines:a comparative study

Monica Silva dos Reis Turolla 13 April 2004 (has links)
Esta Dissertação apresenta informações gerais sobre os medicamentos fitoterápicos e os aspectos toxicológicos de uma amostra de dez plantas medicinais comercializadas como medicamentos fitoterápicos no Brasil, pesquisados junto aos principais bancos de dados e fontes públicas de informação. A análise dos medicamentos fitoterápicos cobre as dimensões histórica, econômica e farmacêutica. No tocante aos aspectos toxicológicos, foram avaliados os dados de toxicidade pré-clínica de dez plantas selecionadas, e realizado um levantamento das informações publicadas para Hypericum perforatum e Piper methysticum, relacionadas ao termo toxicidade, segundo três importantes bancos de dados. Adicionalmente, este trabalho aborda as propostas para realização de ensaios de toxicidade pré-clínica para os fitoterápicos segundo a OMS e legislação brasileira, e as normas para avaliação de substâncias químicas segundo a OECD. / This thesis presents general information on herbal medicines and on the toxicological aspects of a sample of ten medicinal plants traded as herbal medicines in Brazil. The survey was carried out in the main databases and public sources of information. The analysis on the herbal medicines encompasses the historical, economic and pharmaceutical dimensions. In what concerns toxicological aspects, data on pre-clinical toxicity were evaluated for Hypericum perforatum and Piper methysticum, these keywords being related to toxicity in three important databases. In addition, this study discusses the proposals for pre-clinical toxicity trials on herbal medicines according to WHO and the Brazilian legislation, and the standards for evaluation of chemical substances according to OECD.

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