Plusieurs médicaments utilisés chez l'humain peuvent exercer des effets hépatotoxiques que l'on peut évaluer en système de culture primaire d'hépatocytes. On attribue aux hépatocytes des fonctions physiologiques essentielles. Ainsi, entre autres, ils sont impliqués dans le métabolisme des lipides, des glucides et des protéines. De plus, les hépatocytes constituent le principal site du métabolisme des médicaments, et c'est spécifiquement à leur niveau que se manifeste l'hépatotoxicité médicamenteuse. Celle-ci peut mener à de graves maladies hépatiques parmi lesquelles l'insuffisance hépatique aiguë, qui s'avère associée à une incidence de mortalité de 45 à 95% selon l'étiologie. Nous avons donc entrepris l'étude, en culture primaire d'hépatocytes de rat sur film de collagène, du Mintezol™(thiabendazole) et du Posicor™ (mibéfradil), deux médicaments dont les mécanismes d'hépatotoxicité ne sont pas bien connus. Le thiabendazole est un antihelminthique et fongicide, alors que le mibéfradil était autrefois employé pour le traitement de l'hypertension et de l'angine de poitrine. De plus, l'analgésique et antipyrétique Tylénol™ (acétaminophène ou APAP), dont les mécanismes d'hépatotoxicité sont connus, a servi de composé de référence. Nous avons évalué, pour chaque médicament, l'hépatotoxicité et le métabolisme de même que le type et le mécanisme de mort cellulaire induit. Les résultats obtenus montrent que c'est le mibefradil (5-20 µM, 24 et 48 h) qui mène aux changements morphologiques les plus importants et affecte le plus la viabilité et le niveau de synthèse d'albumine des hépatocytes. Nous avons de plus observé une augmentation de la mort cellulaire par nécrose avec la concentration et le temps (24 h, 48 h) pour le mibéfradil (5-20 µM) et l'APAP (10-40 mM). Toutefois, avec le thiabendazole (100-500 µM, 24h et 48h), peu de cytotoxicité ou d'effets sur la fonction métabolique des hépatocytes ont été détectés. Aussi, l'activité du 7-éthoxyresorufin-o-deethylase (EROD), un substrat du CYP1A1, a été induite par le thiabendazole (100-500 µM) et l'APAP (10-40 mM), après 24 h et 48 h, alors que le mibéfradil (5-20 µM, 24 h et 48 h) n'a exercé aucun effet. Toutefois, l'activité du 7-pentoxyresorufin-o-dealkylase (PROD), un substrat du CYP2B, a été induite par les 3 médicaments, dans les mêmes conditions que pour la mesure de EROD. Nous avons par ailleurs mesuré une induction globale de la mort cellulaire par apoptose, détectée par la condensation de la chromatine, avec les médicaments. Cette induction s'est manifestée par une activation des caspases-3, -8 et -9 par le thiabendazole (200 µM) et l'APAP (5 mM) après 1 h d'exposition, et par le mibéfradil (5 µM) après 3 h (caspase-2) et 12 h (caspases-3 et -8). Aux mêmes concentrations, ces médicaments ont de plus induit une baisse du potentiel membranaire mitochondrial et une libération de cytochrome c dans le cytosol (1 h thiabendazole et APAP; 3 h mibéfradil), et la translocation de la protéine «Fas-associated death domain» (FADO) du cytosol aux membranes (1 h thiabendazole et APAP; 12 h mibéfradil). Ainsi, d'une part, le mibéfradil serait plus hépatotoxique que l'APAP et le thiabendazole. D'autre part, l'étude de la signalisation apoptotique suggère que les médicaments étudiés activent tous la voie mitochondriale de l'apoptose de même que celle des récepteurs de mort. Cette étude contribue à l'avancement des connaissances sur l'hépatotoxicité du mibéfradil et du thiabendazole, en apportant une meilleure compréhension de l'hépatotoxicité de ces médicaments. Ceci permettra d'explorer des moyens de diminuer la toxicité du thiabendazole, et de diriger la recherche sur le développement de médicaments similaires au mibéfradil démontrant moins d'hépatotoxicité. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Mibéfradil, Thiabendazole, Acétaminophène, Apoptose, Nécrose, Hépatocytes, Hépatotoxicité, Caspases, Albumine.

Orientador: Francisco Benedito Teixeira Pessine / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-20T02:39:48Z (GMT). No. of bitstreams: 1 Alexandrino_GuilhermeLionello_M.pdf: 6401639 bytes, checksum: 74c410c18bcea29a9d36cd3c84b3cfe9 (MD5) Previous issue date: 2011 / Resumo: Tiabendazol (TBZ) é um fármaco pouco solúvel em água (66 mg/mL), derivado do benzimidazol, com ampla aplicação farmacológica, devido a suas propriedades anti-helmíntica, fungicida e bactericida. O aumento em sua solubilidade pode ser atingido preparando complexos de inclusão com Ciclodextrinas (bCD), que são polissacarídeos cíclicos de D-(+)-glicopiranose unidas por meio de ligações glicosídicas a-1,4, cuja estrutura resulta em um ambiente interno hidrofóbico e uma superfície e extremidades hidrofílicas. Neste trabalho, a preparação de complexos de inclusão entre TBZ e bCD foi realizada pelo método de co-precipitação, em duas metodologias que diferiram na etapa de solubilização do TBZ: empregando etanol ou meio ácido com HCl em pH 2.2. Os complexos preparados foram caracterizados no estado sólido, através das técnicas de espectroscopia de absorção no i.v., difratometria de raios-X e análise termogravimétrica. Em solução, a estabilidade termodinâmica do complexo de inclusão TBZ:bCD foi investigada em meios que simulam os fluídos gástrico e intestinal humano, sem enzimas, determinando as constantes de equilíbrio K nas temperaturas 25 (150 ± 31), 37 (85 ± 32) e 45 ºC (83 ± 23), e as funções termodinâmicas de formação DHº (-24 kJ/mol), DS º (-39 J/mol.K) e DGº (-12,5 kJ/mol), através de dados de espectroscopia de fluorescência. Além disso, a estrutura supramolecular deste complexo em água foi investigada por RMN, a partir de espectros de dados de deslocamento químico em espectros de H e do experimento ROESY-1D, em que o último sugere encapsulação do fármaco através de seu grupo benzimidazol, além da determinação dos coeficientes de difusão e K (49 a 25ºC) por DOSY, em D2O. Os dados experimentais sobre estabilidade termodinâmica e informações estruturais foram confrontados com resultados obtidos de cálculos teóricos de otimização molecular e determinação de energias de conformações e interações, realizados com os métodos quânticos PM3 e DFT (vacuo) e PM6 (meio aquoso) / Abstract: Thiabendazole (TBZ) is a poorly water soluble drug derived from benzimidazole with wide pharmacological, fungicide and bactericide applicability. The enhancement of its water solubility can be achieved through formation of inclusion complexes with beta-Cyclodextrin (bCD), a cyclic polysaccharide from D- (+)-glicopyranose units linked by a-1,4 chemical bonds, whose structure has a hydrophobic cavity and a hydrophilic surface and extremities. This work involves the preparation of inclusion complexes with TBZ and bCD by the co-precipitation method, using two methodologies for the TBZ solubilization step: with ethanol or HCl medium (pH 2.2). The inclusion complexes were characterized on solid state by infrared spectroscopy, X-ray diffractometry and thermogravimetric analysis. The thermodynamic stability of TBZ:bCD inclusion complex was investigated in human simulated gastric and intestinal fluids but without the respective enzymes. Equilibrium constants K at the temperatures of 25 (150 ± 31), 37 (85 ± 32) and 45ºC (83 ± 23), and the thermodynamic functions DH º (-24 kJ/mol), DS º (-39 J/mol.K) and DG º (-12,5 kJ/mol) were evaluated through fluorescence spectroscopy. The supramolecular structure of this complex in aqueous solution was extensively investigated by NMR spectroscopy, based on H chemical shift and ROESY-1D experiments, with the latter one suggesting the drug interacts with the CD through its benzimidazole group. NMR-based experiment DOSY was also employed to get the diffusion coefficients and K (49 at 25ºC), in D2O. Experimental results on thermodynamic stability and structural information were compared with theoretical calculations of TBZ:bCD molecular optimization and determination of conformation and interaction energies of related structures. The calculations of the isolated species, in vacuum, were performed by PM3 and DFT methods, while PM6 method was employed for calculation simulating the aqueous media / Mestrado / Físico-Química / Mestre em Química

L’usage excessif des pesticides a entraîné de nombreux effets néfastes sur l’environnement et aussi sur la santé des populations. Il est donc important d’approfondir, nos connaissances sur leur comportement dans toutes les sphères de l’environnement et de mettre en place de nouvelles technologies de dépollution d’effluents chargé en pesticides avant leur rejet dans le milieu naturel. Le travail de cette thèse est situé dans ce contexte. Le premier volet de thèse a été consacré au traitement des solutions aqueuses chargées par deux fongicides (imazalil, thiabendazole), par le procédés d’oxydation électrochimiques directe, afin d’optimiser les différents paramètres expérimentaux de leur dégradation. Ces études confirment l’efficacité du procédé électrochimique dans le traitement des eaux polluées par les pesticides, avec un taux de minéralisation qui dépasse 80%. D’autre part, les résultats obtenus dans ce travail ont montré que la nature du matériel d’anode a une grande influence sur la performance du procédé d’oxydation. Dans la deuxième partie, nous avons étudié la réactivité atmosphérique en phase gazeuse des composés aromatiques hétérocycliques azotés. Ces espèces sont attendues lors de la dégradation des pesticides. Les études cinétiques de ces composés avec l’ozone et les radicaux OH, ont été effectuées dans une chambre de simulation atmosphérique à différentes températures. Les réactions d’ozonolyse de ces composés sont très lentes. Dans le cas de leur réaction avec les radicaux OH, les résultats obtenus montrent que la réactivité atmosphérique de ces composés dépend fortement de leur structure moléculaire. En effet, les composés hétérocycliques aromatiques à 5 atomes présentent une réactivité plus importante vis-à-vis les radicaux OH, par rapport aux composés hétérocycliques aromatiques à six atomes. Par ailleurs, ces études ont montrés que la présence des atomes d’azote dans le cycle aromatique a un effet désactivant sur la réactivité de ces composés avec les radicaux OH. Sur le plan spectroscopique, les spectres d’absorption UV-visibles des composés : 1,2,3 triazole, pyrazole, pyrazine, pyrimidine,et pyridazine, ont été déterminés en phase gazeuse et leurs constantes de photodissociation atmosphérique ont été estimées. Enfin, les données cinétiques et spectroscopiques obtenues ont permis de discuter les implications atmosphériques de ces composés en termes de durée de vie par rapport aux différents processus de dégradation atmosphérique / This work concerns a new insight of treatment of organic pollutants pesticides before their rejection in the natural environment. This phenomenon is increasing dramatically causing many adverse effects on the environment and the health. The first step of this work focused on the treatment of aqueous solution charged with fungicides by direct electrochemical processes. The efficiency of this latter in the treatment of waters polluted by pesticides has been confirmed with a mineralization rate exceeding 80%. In the other hand, the obtained results have ensured that the nature of the anode material is one of the keys and factors having an influence on the oxidation pathway. The second step conducted by absorption spectroscopy and focused on the atmospheric reactivity in the gas phase of nitrogenous heterocyclic aromatic compounds. These species are expected during the degradation of pesticides. The use of an atmospheric simulation chamber at different temperatures allowed us to follow the kinetics of these compounds with ozone and OH radicals. The kinetics of ozonolysis of these compounds is very slow. The molecular structure is the factor, according to the results obtained, controlling the atmospheric reactivity of these compounds in the case of their reaction with OH radicals. Indeed, the 5-atom aromatic heterocyclic compounds have a greater reactivity with respect to the OH radicals, compared with six-membered aromatic heterocyclic compounds. Moreover, according to these studies, the presence of nitrogen atoms in the aromatic ring has a deactivating effect on the reactivity of these compounds with the OH radicals. Spectroscopically, the UV-visible absorption spectra of the compounds 1,2,3-triazole, pyrazole, pyrazine, pyrimidine, and pyridazine were determined in the gas phase and their atmospheric photodissociation constants were estimated. Finally, the kinetic and spectroscopic data obtained made it possible to discuss the atmospheric implications of these compounds in terms of their lifetime with respect to the different processes of atmospheric degradation.

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Please refer to full text for abstract / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming

Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources in areas such as campgrounds. Interest in using non-lethal techniques, such as aversive conditioning, to manage such conflicts is growing. I conducted a captive experiment at The Wildlife Science Center in Minnesota and two field experiments in the La Sal Mountains, Utah, to investigate the effects of taste aversion conditioning using thiabendazole (TBZ) with a novel flavor cue and food removal on black bear food consumption and visitation to human food sources. In 2007, I conducted food trials with 6 captive black bears (3 control, 3 treatment). Controls received 1 kg baked goods scented with a peppermint-canola oil mixture and treatments received 1 kg baked goods also scented with a peppermint-canola oil mixture but mixed with 10-20 g TBZ. In the 2007 field experiment, I baited 24 field sites with 300 g of baked goods during a baseline phase for approximately 3 weeks. Half of these sites were then treated with 10 g of TBZ and camphor during a treatment phase for 4 weeks. In 2008, I baited 22 sites with 300 g of baked goods during a baseline phase for approximately 4 weeks. I then removed food and discontinued baiting at half of the sites for 4 weeks. Infrared cameras and barbed-wire hair snags were established at field sites to document bear visitation. I did not establish taste aversion in treated bears in captivity and bears fully consumed food in the majority of trials. Treating food supplies with 10 g TBZ and camphor flavor did not significantly reduce bear visitation (P = 0.615) or food consumption at field sites (P = 0.58). However, I observed a significant reduction in bear activity at sites where food was removed (P = 0.006). Potential reasons for my failure to reduce bear visitation using thiabendazole include insufficient conditioning, reluctance of bears to desist in investigating sites that previously contained untreated food, and masking of a treatment effect due to continued encounters of sites by new individuals.

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-07T15:10:23Z No. of bitstreams: 1 arquivototal.pdf: 4833139 bytes, checksum: bfbf396126ab64ae328a5af2ae825330 (MD5) / Made available in DSpace on 2017-08-07T15:10:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4833139 bytes, checksum: bfbf396126ab64ae328a5af2ae825330 (MD5) Previous issue date: 2017-02-10 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Systems based on clay minerals/drug for application as drug delivery have been studied because of their physical and chemical properties such as good ion exchange, capacity of intercalation, biocompatibility and low toxicity, furthermore their use in pharmaceutical products as excipients and active agents. Therefore in this work, a bentonite sample, which had montmorillonite as principal constituent, was modified through ion exchange with sodium (BentNa), calcium (BentCa) and magnesium (BentMg) and the obtained solids were applied for sorption of thiabendazole (TBZ) for possible use as controlled release systems. Precursor, exchanged and hybrid bentonites were characterized by X-ray diffraction, infrared spectroscopy, solid state UV-Vis spectroscopy, CHN elemental analysis, thermogravimetry and transmission electron microscopy (TEM). In the study of the The interactions between the solids with thiabendazole were investigated in function of parameters such as pH, contact time and initial concentration of drug. The better conditions in the thiabendazole loading tests were at pH 1.4 and 45 min at 2000 mg L-1 thiabendazole for BentNa and 105 min and 1300 mg L-1 for BentCa and BentMg, which conditions were adopted and resulted in maximum adsorbed quantities of TBZ of 164.4; 152.3 and 133.3 mg g-1 for BentNa, BentCa and BentMg, respectively. The XRD patterns suggested the formation of intercalation hybrid with basal spacings of 1,42; 1,41 e 1,39 nm for BentNa, BentCa e BentMg, respectively. The obtained emission profile for the bentonite/TBZ hybrids were similar in simulated body fluids, and their data were fitted to Korsmeyer-Peppas kinetic model. / Os sistemas baseados em argilominerais/fármacos para aplicação em liberação controlada têm sido estudados, devido às propriedades físicas e químicas dos filossilicatos como boa capacidade de troca catiônica, possibilidade de intercalação, biocompatibilidade e baixa toxidade, além de já serem utilizados em produtos farmacêuticos como excipientes e agentes ativos. Neste trabalho uma argila bentonítica, contendo como fase principal montmorillonita, foi modificada por troca iônica com sódio (BentNa), cálcio (BentCa) e magnésio (BentMg) e os sólidos trocados aplicados para adsorção do tiabendazol (TBZ) visando aplicação em sistemas de liberação controlada. A bentonita precursor, bentonitas trocadas e híbridas foram caracterizados por difratometria de raios X (DRX), espectroscopia na região do infravermelho, UV-Vis no estado sólido, termogravimetria, análise de CHN e microscopia eletrônica de transmissão. Os parâmetros como pH, tempo de contato e concentração inicial do fármaco foram avaliados nos estudos de interação dos sólidos com o tiabendazol. As melhores condições para o carreamento do tiabendazol nos sólidos ocorreram a pH 1,4 em 45 min com o fármaco a 2000 mg L-1 para a BentNa e em 105 min e 1300 mg L-1 para BentCa e BentMg, cujos teores de TBZl adsorvidos foram 164,4; 152,3 e 133,3 mg g-1 para BentNa, BentCa e BentMg, respectivamente. Os resultados de DRX sugeriram a formação de híbridos de intercalação com espaçamentos basais de 1,42; 1,41 e 1,39 nm para BentNa, BentCa e BentMg, respectivamente. Os perfis de liberação para os sistemas bentonitas/TBZ foram semelhantes em fluidos corpóreos simulados, cujos dados se ajustaram ao modelo cinético de Korsmeyer-Peppas.

Orientador: Anne Hélène Fostier / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T15:16:43Z (GMT). No. of bitstreams: 1 OliveiraNeto_OdilonFrancade_M.pdf: 1924906 bytes, checksum: 29671521f8cf4efd410c90740f77e9aa (MD5) Previous issue date: 2015 / Resumo: A presença de resíduos de produtos farmacêuticos de uso humano e veterianário no meio ambiente tem sido motivo de preocupação na comunidade científica. Um desses produtos é o agente anti-helmíntico Tiabendazol (TBZ), amplamente usado na medicina veterinária e na agricultura. Os dados referentes ao comportamento do TBZ em solos brasileiros são escassos, e a extrapolação de dados oriundos de outras regiões não é coerente devido às especificidades do clima e dos solos de cada região. A sorção do TBZ foi avaliada seguindo as recomendações do guia 106 da OECD, e sua quantificação nas soluções de solos foi feita por espectroscopia UV (299 nm). Além disso, foram realizados estudos cinéticos e construção de isotermas, para quatro solos do estado de São Paulo, Neossolo Quartzarênico (N1), Latossolo Vermelho (N2), Latossolo Vermelho-Amarelo (S1) e Argilossolo Vermelho-Amarelo (S2). A distinção de comportamento cinéticos nas duas faixas de pH, onde predominam formas distintas do TBZ (catiônica e neutra), reforça a diferenciação dos mecanismos de sorção em função do pH. Três modelos de isotermas foram testados em três faixas de pH (2,5 a 3,0; 3,8 a 4,2 e 5,5 a 5,7) ¿ Freundlich, Langmuir e partição hidrofóbica. As isotermas de partição hidrófóbica apresentaram altos coeficientes de correlação (r2 > 0,97), nas três faixas de pH, no entanto, devido ao caráter ionizável do TBZ as correlações não podem ser relacionadas diretamente a hidrofobicidade do composto. As isotermas de Freundlich apresentaram correlações > 0,97, para as três faixas de pH. Os valores de KF mostraram que a especiação do TBZ, promovida pelo pH, influencia em sua capacidade de adsorção nos solos. O solo N1 apresentou a menor capacidade adsortiva nas três faixas de pH, o N2, a maior, nas duas faixas mais baixas e o solo S1, a maior capacidade na faixa de pH 5,5 a 5,7. As isotermas de dessorção apresentaram valores de KF superiores à etapa de adsorção. Os resultados obtidos indicam que o TBZ apresenta boa mobilidade nos perfis dos solos estudados, podendo acarretar riscos aos recursos hídricos. E a fração que permanece retida pode oferecer riscos a microbiota do solo, considerando que medicamentos são projetados para serem eficientes mesmo em baixas concentrações / Abstract: The presence of pharmaceuticals residues for human and veterinary use in the environment has been concerned in the scientific community. One of these products is the anthelmintic drugs Thiabendazole (TBZ), widely used in veterinary medicine and in the agriculture. The data regarding to TBZ behavior in Brazilian soils are scarce, and data extrapolation from other regions is not consistent due to the peculiarities climate and soils of each site. The sorption of TBZ was evaluated following the OECD guideline 106 recommendations, and its quantification in soil solutions was made by UV spectrophotometry (299 nm). Furthermore, kinetic studies were performed and isotherms were constructed for four soil for the State of São Paulo, Neossolo Quartzarenic (N1), Oxisol red (N2), Oxisol Red-yellow (S1) and Argisol Red-yellow (S2). The distinction in the kinetic behavior at the two pH ranges, where the most distinct TBZ forms (cationic, neutral) predominate, enhances the differentiation of the sorption mechanisms as a function of pH. Three models of isotherms were tested in three pH ranges (2.5 to 3.0; 3.8 to 4.2 and 5.5 to 5.7) ¿ Freundlich, Langmuir and hydrophobic partitioning. The hydrophobic partitioning isotherms presented high correlation coefficients (r2 > 0.97) on the three pH ranges, however, due to the ionizable TBZ character the correlations may not be directly related to the compound hydrophobicity. The Freundlich isotherms showed correlations > 0.97 for the three pH ranges.The KF values showed that the speciation of TBZ, promoted by pH, influence on its adsorption capacity in the soil. The N1 soil presented the lowest adsorptive capacity in the three pH ranges, the N2, the largest in the two lower pH ranges and the soil S1, the largest capacity in the pH range from 5.5 to 5.7. The desorption isotherms showed KF values higher than the adsorption step.The obtained results indicate that TBZ has good mobility in soil profiles studied and this may carry risks to water resources. Moreover, the retained fraction can present risks to soil microbiota, considering that drugs are designed to be efficient even at low concentrations / Mestrado / Quimica Analitica / Mestre em Química

A scaris is a genus of parasitic worms (helminths) found in the small intestine of various mammalian hosts, including Ascaris lumbricoides in humans, Parascaris equorum and P univalens in horses, Ascaris suum in pigs, Toxocara cati in cats and Toxocara canis in dogs. To date, Parascaris spp. are the only Ascaris worms that have developed resistance to anthelmintic drugs. The mechanisms of resistance in Parascaris spp are incompletely understood, partly due to the absence of robust in-vitro models. Further complicating in-vitro studies, Parascaris spp lack a free-living larval stage as their larva only hatch within the host. The aim of this study was to develop in-vitro methods for hatching, scoring the viability of Parascaris L3 larvae and exposing them to the anthelmintic drugs ivermectin, pyrantel, thiabendazole, and the herbal extract carvacrol. This study shows that mechanical Ascaris egg breaking using a homogenizer resulted in a hatching rate of 98%. Our viability scoring system could distinguish an ivermectin resistant larvae from an ivermectin susceptible larvae derived from different farms. This indicates that this method may have utility for the screening of larvae ivermectin resistance on the level of farm populations. Interestingly, a highly paralytic effect observed after carvacrol exposure. Carvacrol shows direct paralytic effects on Parascaris larvae in a dose-dependent manner, as higher concentrations were lethal to all exposed larvae. This result presents a potential future opportunity for carvacrol used in the treatment of Ascaris infections. To conclude our results, we have successfully developed an in-vitro model as well as a scoring system for the viability of Parascaris L3 stage larvae, which can be used for assaying the effect on larvae after drug exposure