A Uncaria tomentosa (U. tomentosa), popularmente conhecida como \"Unha-de-gato\", é uma planta medicinal nativa das Américas, mundialmente empregada devido às suas atividades anti-inflamatórias e imunomodulatórias. O consumo desta planta ocorre não apenas na forma in natura, mas principalmente como fitoterápico, sendo muitas vezes utilizada de forma indiscriminada pela população. Apesar de vários estudos revelarem as propriedades terapêuticas da U. tomentosa, poucos são os trabalhos que empregam protocolos estabelecidos por agências regulamentadoras internacionais, para a avaliação dos possíveis efeitos tóxicos e imunotóxicos deste fitoterápico. Assim, o propósito do presente estudo foi verificar se a administração de um extrato seco de U. tomentosa, comercialmente disponível no mercado, poderia ocasionar efeitos tóxicos e imunotóxicos em ratos após 90 dias de tratamento. Para isso, 40 ratos Wistars machos foram tratados oralmente com as doses de 15, 75 ou 150 mg/kg de extrato seco de U. tomentosa comercialmente disponível no mercado, contendo teores de alcaloides de acordo com aqueles valores preconizados em literatura. No final do período experimental, os animais foram submetidos à eutanásia para realização de avaliações bioquímicas, hematológicas, histopatológicas, análise de órgãos linfoides e não-linfoides, avaliação das respostas imunes inata, inflamatória e humoral, bem como teste para determinação de reação de hipersensibilidade do tipo IV. Os resultados revelaram aumento nos níveis de ALT dos animais tratados com a dose de 75 mg/kg, e redução nos índices glicêmicos de ratos tratados com 75 e 150 mg/kg de U. tomentosa. Entretanto, somente os ratos tratados com a maior dose exibiram discreta vacuolização centro-lobular hepática; assim, somente os dados de ALT não são sugestivos de efeitos hepáticos adversos da U. tomentosa após um longo período de tratamento. A redução nos índices sanguíneos de glicose dos ratos, após tratamento com a U. tomentosa, podem representar importante risco para seres humanos diabéticos, susceptíveis ao desenvolvimento de hipoglicemia e que fazem uso da U. tomentosa para outros propósitos. Em conclusão, estes estudos demonstraram que, apesar de a U. tomentosa não promover efeitos tóxicos e imunotóxicos, o uso prolongado da mesma, a altas doses, pode promover redução dos índices glicêmicos. / Uncaria tomentosa (U. tomentosa), commonly known as \"Cat\'s claw\", is a native medicinal plant from America, it is employed worldwide for its anti-inflammatory and immunomodulatory activities. The consumption of this plant occurs not only in natura, but mainly as a phytotherapic, used indiscriminately by the population. Although many researchers revealed the therapeutic properties of U. tomentosa, few studies employing established protocols by international regulatory agencies for the evaluation of the possible toxic and immunotoxic effects of this herbal medicine. Thus, the purpose of the present study was to verify if the dry extract of U. tomentosa could promote toxic and/or immunotoxic effects in rats following 90 days of treatment. For this, forty male rats were orally treated with 15, 75 or 150mg/kg of dry extract of U. tomentosa, commercially available, containing levels of alkaloids according to those values recommended in the literature. At the end of experimental period, the rats were killed for the evaluation of the biochemistry, haematology, histopathology, status of the lymphoid and non-lymphoid organs, evaluation of innate, inflammatory and humoral immune responses, as well as a test to determine the delayed type hypersensitivity. The results revealed an increase in the levels of ALT in the animals treated with 75mg/kg and a reduction in the glycaemic levels of rats treated with 75 and 150mg/kg of U. tomentosa. However, only rats treated with the higher dose showed a slight centrilobular hepatic vacuolation; thus, ALT data alone are not suggestive of a hepatic adverse effect of U. tomentosa following long-term treatment. The reduction in blood glucose levels of the rats, could represent an important risk for diabetic humans, who are susceptible to the development of hypoglycaemia and who might use U. tomentosa for purposes other than anti-diabetes. In conclusion, these studies demonstrated that, while U. tomentosa has no immunotoxic effect, long-term U. tomentosa treatment at high doses can promote reduction in glycemic levels.

O crack, uma droga de abuso constituída principalmente por cocaína, continua sendo um grande problema social e de saúde pública. Apesar de vários estudos em modelos animais com outras formas de cocaína, raros são os relatos sobre os efeitos da exposição pulmonar ao crack em roedores, devido à dificuldade de realizar a exposição dos mesmos à droga, o que seria de grande valia, uma vez que eliminaria variáveis encontradas em usuários, como o uso de outras drogas. Assim, o propósito do presente estudo foi avaliar os efeitos tóxicos, imunotóxicos e ainda, alterações comportamentais de ratos Wistar machos expostos ao crack pela via pulmonar. Inicialmente, foram realizadas determinações de cocaína nas pedras de crack utilizadas e também, a quantidade de crack e tempo de exposição dos animais para obtenção de níveis séricos de cocaína semelhantes àqueles encontrados na literatura, e os dados obtidos foram de: 67% de cocaína no crack e a queima de 250 mg de crack, com exposição dos animais por 10 minutos acarretou em níveis plasmáticos próximos de 170 ng/mL de cocaína. Assim, em cada experimento foram utilizados 30 ratos divididos em 3 grupos iguais, um controle, um experimental e um grupo pair-fed, já que a cocaína promove efeitos anorexígenos que poderiam interferir nas avaliações comportamentais e imunológicas aqui estudadas, e que foram expostos ou não à fumaça resultante de 250 mg de crack, por 10 minutos, duas vezes ao dia, durante 28 dias. Ao final do período experimental, os animais foram submetidos à eutanásia para realização de avaliações bíoquimicas, hematológicas, histopatológicas, análise de órgãos-linfóides, avaliação das respostas imune inata (inflamatória), humoral e a avaliação da reação de hipersensibilidade do tipo IV. Ainda, ao longo do período experimental, estes mesmos animais foram avaliados quanto a possíveis alterações comportamentais e para tal foram utilizados 3 métodos distintos: avaliação cognitiva em labirinto em T, avaliação geral do comportamento em campo aberto e ainda, a avaliação de preferência ou aversão ao odor da droga. A exposição ao crack não resultou em alterações que caracterizem toxicidade em parâmetros clínicos, bioquímicos, hematológicos e histopatológicos; não foram observadas alterações com significado clínico nas avaliações do peso relativo, celularidade, morfometria de órgãos linfoides e fenotipagem de linfócitos esplênicos de ratos expostos à droga. Não houve efeitos imunomodulatórios nas avaliações do burst oxidativo e fagocitose de macrófagos peritoneais e de neutrófilos circulantes, assim como nas avaliações da produção de anticorpos T-dependentes e na reação de hipersensibilidade do tipo IV. Quanto às avaliações comportamentais, os animais expostos à droga apresentaram aumento da atividade locomotora, e uma maior preferência ao odor característico do crack, aparentemente sem prejuízo cognitivo. Em conclusão, a exposição de ratos 2 vezes ao dia, por 28 dias ao crack não promoveu alterações imunotóxicas; por outro lado, comportamentos clássicos da exposição à cocaína foram observados nos animais expostos, evidenciando que o modelo aqui utilizado será de grande utilidade para outros estudos que envolvam drogas de abuso, como possíveis estratégias terapêuticas e o melhor entendimento da toxicocinética de drogas utilizadas pela via pulmonar / Crack cocaine, a drug of abuse that consists mainly of cocaine, remains as a major social and public health problem. Although several studies in animal models with other forms of cocaine, there are few scientific reports on the effects of pulmonary exposure to crack in rodents, this is due to the difficulty of performing their exposure, which would be of great value, since would eliminate variables observed in users, such as the use of other drugs. Initially, the concentration of cocaine in crack samples, as the amount of crack and time of exposure of the animals to obtain serum levels of cocaine similar to those found in the literature were determined, and the data obtained were: 67% of cocaine in crack, and 250 mg of crack, exposing the animals for 10 minutes resulted in plasma levels close to 170 ng/mL of cocaine. Thus, the purpose of this study was to evaluate the toxic effects, immunotoxic and behavioral changes of male Wistar rats exposed to crack cocaine. Thus, in each experiment were used 30 rats divided into three groups, one control, one experimental and one pair-fed, since it is known that cocaine promotes anorexic effects that may interfere with behavioral and immunological assessments that will be studied here, and who were exposed or not to the burning of 250 mg of crack, for 10 minutes, twice daily for 28 days. At the end of the experiment, the animals were euthanized to perform biochemical evaluation, hematological, histopathological, analysis of lymphoid organs, evaluation of innate immune responses (inflammatory), humoral and the assessment of the type IV hypersensitivity reaction. Still, throughout the experimental period, these same animals were evaluated for possible behavioral changes and were used three different methods: cognitive assessment in T-maze, overall assessment on open field behavior and the evaluation of preference or aversion to the odor of the drug. Exposure to crack cocaine, did not result in changes that characterize toxicity in clinical, biochemical, hematological and histopathological parameters; were not observed clinically meaningful changes in the relative weight ratings, cellularity, morphology of lymphoid organs and phenotyping of splenic lymphocytes from rats exposed to the drug. There was no immunomodulatory effect in the evaluations of oxidative burst and phagocytosis of peritoneal macrophages and in circulating neutrophils, and the assessments of the production of T-dependent antibodies and the type IV hypersensitivity reaction. With regard to behavioral assessments, the animals exposed to the drug showed increased locomotor activity, and greater preference to the characteristic odor of crack cocaine, apparently without cognitive impairment. In conclusion, in the exposure model to crack cocaine used here, immunotoxic changes were not evident; by contrast, classic behavior of cocaine exposure were observed in the animals exposed, indicating that the model used herein will be useful for the study of other parameters involving drugs of abuse, in evaluation of therapeutic strategies and a better understanding of drugs toxicokinetics used by the pulmonary route

Cytokines are pleiotropic and redundant signaling molecules that govern the inflammatory response and immunity, a critical ecological parameter for organism success and population growth. Produced at the site of injury or pathogen intrusion by a variety of cell types, cytokines mediate cell-signaling in either an autocrine or paracrine manner. The type and magnitude of the cytokine milieu produced subsequently dictates the strength and form of immune response. As the most diverse vertebrate group, with a high sensitivity to contaminants, fish represent an important foci for the evaluation of immune system evolution, function, and alteration upon toxicant exposure. While many cytokines have been identified in teleosts, primary study has been limited to model species (e.g. zebrafish and fugu). However, evidence exists for several variations of cytokine genes within taxa, underscoring the need for species-specific evaluation. In this study, two pro-inflammatory cytokines (IL-1β and TNFα ), one chemokine (IL-8), and one anti-inflammatory cytokine (IL-10) were cloned, sequenced, and characterized for the first time in two commercially relevant Perciformes in the Gulf of Mexico, golden tilefish (Lopholatilus chamaeleonticeps) and red snapper (Lutjanus campechanus). The complete amino acid sequence was obtained and confirmed for IL-β and IL-8 from golden tilefish and for IL-8, IL-10, and TNFα from red snapper, with partial sequences obtained for the remaining proteins. The results indicate high homology among Perciformes for all cytokines studied, but divergence with other teleost orders, and low conservation when compared to birds, amphibians, and mammals. The sequences will be used to create a multi-plexed antibody-based assay for the routine detection of cytokines in teleost serum. This would allow the biochemical response to fish health challenges, such as oil spills and other contamination events, to be monitored at the protein level, building upon the current regime of genetic biomarkers. Thus, this work will aid in the understanding of how oil spills and other contamination events may alter the immune response in fishes.

<p>Pesticides are designed to control or eliminate pests such as insects, rodents, weeds,<br /> bacteria, and fungi. They are used at a global scale for agricultural produce. Although<br /> pesticides play a significant role in increasing food production and eliminating diseases,<br /> exposure to pesticides may be harmful to non-target organisms. As a result concern over<br /> safety and resistance to pesticides has increased and there is pressure to reduce use and<br /> search for more environmentally and toxicologically safe and efficacious pesticides. Most<br /> pesticides currently in use are synthetic / therefore an alternative to synthetic pesticides is<br /> the use of naturally occurring products/ botanicals with pesticidal properties.</p> <p>Two plants indigenous to South African with pesticidal properties were chosen for this<br /> study. Dicerothamnus rhinocerotis (D. rhinocerotis) and Galenia africana (G. africana)<br /> have potential antifungal properties thus, may have potential use on agricultural produce<br /> as fungicides. Galenia africana and D. rhinocerotis extracts inhibit growth of B. cinerea<br /> (a fungal pathogen) at concentrations greater than 31.25 mg/ml and 125mg/ml<br /> respectively. A major consideration in approving pesticides for use is whether they pose<br /> an unreasonable risk to humans and to the environment. Toxicity studies are required to<br /> determine the safety of the plant extracts.</p> <p>The purpose of this study was to evaluate potential toxicity of ethanol extracts of D.<br /> rhinocerotis and G. africana, which is important when designing practices to reduce or<br /> eliminate excess exposure to them. Natural plant products with pesticidal properties could<br /> provide an alternative to synthetic pesticides and may thus effectively reduce resistance<br /> levels.<br /> <br /> <br /> &nbsp / </p>

<p>Pesticides are designed to control or eliminate pests such as insects, rodents, weeds,<br /> bacteria, and fungi. They are used at a global scale for agricultural produce. Although<br /> pesticides play a significant role in increasing food production and eliminating diseases,<br /> exposure to pesticides may be harmful to non-target organisms. As a result concern over<br /> safety and resistance to pesticides has increased and there is pressure to reduce use and<br /> search for more environmentally and toxicologically safe and efficacious pesticides. Most<br /> pesticides currently in use are synthetic / therefore an alternative to synthetic pesticides is<br /> the use of naturally occurring products/ botanicals with pesticidal properties.</p> <p>Two plants indigenous to South African with pesticidal properties were chosen for this<br /> study. Dicerothamnus rhinocerotis (D. rhinocerotis) and Galenia africana (G. africana)<br /> have potential antifungal properties thus, may have potential use on agricultural produce<br /> as fungicides. Galenia africana and D. rhinocerotis extracts inhibit growth of B. cinerea<br /> (a fungal pathogen) at concentrations greater than 31.25 mg/ml and 125mg/ml<br /> respectively. A major consideration in approving pesticides for use is whether they pose<br /> an unreasonable risk to humans and to the environment. Toxicity studies are required to<br /> determine the safety of the plant extracts.</p> <p>The purpose of this study was to evaluate potential toxicity of ethanol extracts of D.<br /> rhinocerotis and G. africana, which is important when designing practices to reduce or<br /> eliminate excess exposure to them. Natural plant products with pesticidal properties could<br /> provide an alternative to synthetic pesticides and may thus effectively reduce resistance<br /> levels.<br /> <br /> <br /> &nbsp / </p>

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), manufactured for a variety of industrial and consumer applications, are ubiquitous environmental pollutants. Their accumulation in humans and wildlife raises serious health concerns. Here, we examined the potential effects of PFOA and PFOS on the innate immune system in mice. Short-term dietary exposure to high doses reduces the total number and subpopulations of circulating white blood cells. Moreover, production of proinflammatory cytokines by macrophages in the peritoneal cavity and bone marrow, but not in the spleen following exposure to in vitro or in vivo stimulation by bacterial lipopolysaccharides is enhanced. With respect to adaptive immunity, PFOS reduces the total numbers of thymocytes and splenocytes and subpopulations thereof in a dose dependent fashion. Furthermore, comparison of wild-type mice and the corresponding knock-out strain lacking peroxisome proliferator-activated receptor-alpha revealed that these immunological changes are partially dependent on this receptor. Our further studies also show that sub-chronic dietary exposure to an environmentally relevant dose of PFOS does not alter the cellularity of the thymus and spleen and exerts no influence on humoral immune responses. To facilitate examination of the effects of PFOA and PFOS on the hepatic immune system, we developed a procedure for mechanical disruption that yields a larger number of functionally competent immune cells from this organ. In our last study, lower doses of PFOA or PFOS induced hypertrophy of hepatocytes and altered the hepatic immune status. Thus, we find that short-term, high- and low-dose exposure of mice to these fluorochemicals is immunohepatotoxic. / Perfluorooktanat (PFOA) och perfluorooktansulfonat (PFOS) som tillverkas för många olika industri och konsumentprodukter, är globalt förekommande miljögifter. Deras ackumulering i människor och djur ger upphov till en stark oro för hälsoproblem. Vi har granskat effekterna av PFOA och PFOS på det medfödda, ospecifika immunförsvaret. Exponering för höga doser via maten under kort tid minskar det totala antalet cirkulerande vita blodkroppar samt delpopulationerna.. Immunsvaret ökar dock efter stimulering med bakteriella lipopolysaccharider både in vitro och in vivo , dvs produktionen av proinflammatoriska cytokiner av makrofager i bukhålan och benmärgen, men inte i mjälten ökar.. När det gäller adaptiv, specifik immunitet minskar PFOS det totala antalet tymocyter och splenocyter och deras olika subpopulationer. Vid exponering för lägre doser av PFOS induceras hepatomegali utan att påverka tymus eller mjälten.   Vi kunde visa att peroxisomal proliferator-aktiverad receptor-alfa medierar effekterna utav PFOS i tymus samt delar av effekterna av PFOS i mjälten genom att använda möss som saknade denna receptor. . Dettastöds av vår studie med subkronisk exponering för en miljömässig dos av PFOS vilken inte ändrade den cellulära sammansättningen i vare sig  tymus eller mjälte och inte hade  något inflytande på det humorala immunsvaret. För att underlätta studier av hur PFOA och PFOS påverkar immunsystemet i levern utvecklade vi en metod för framrening av immunceller via mekanisk sönderdelning av levern, vilket gavett större antal av funktionella  immunceller från detta organ. I vår sista studie kunde vi påvisa att lägre doser av PFOA eller PFOS inducerade hypertrofi av hepatocyter samt en påverkan av leverns immunförsvar.

Aves domésticas são um dos principais alvos da contaminação alimentar com micotoxinas. O que contribui para o aumento dos prejuízos da indústria avícola devido a problemas como: alta mortalidade, redução do ganho de peso, alteração da conversão alimentar, imunossupressão, anormalidades embrionárias e morte embrionária precoce. Além disso, o acúmulo residual de micotoxinas na carne é uma preocupação da Saúde Pública. Diversos métodos são utilizados para a avaliação da citotoxicidade induzida por agentes tóxicos, incluindo a inibição do crescimento celular, a avaliação da capacidade celular de sintetizar macromoléculas necessárias para a replicação e da capacidade desse agente tóxico para induzir a peroxidação lipídica. Sendo assim, o objetivo geral do presente estudo foi avaliar os efeitos in vitro de ocratoxina A, deoxinivalenol e zearalenona sobre o sistema imunológico de frangos de corte, utilizando como parâmetros, a viabilidade celular, a atividade enzimática e o estresse oxidativo. Realizou-se cultivo primário de linfócitos das aves e o seu isolamento através da técnica de centrifugação por gradiente de densidade. Cada micotoxina foi adicionada ao meio celular, em uma confluência de 80%, em diferentes concentrações (0,001; 0,01; 0,1 e 1 μg/mL), analisando-se viabilidade celular, atividade de ecto-adenosina desaminase e acetilcolinesterase por ensaios colorimétricos e peroxidação lipídica através dos níveis de malondialdeído mensurados pela técnica de substâncias reativas ao ácido tiobarbitúrico. Todos esses parâmetros foram analisados em 24, 48 e 72 h, em triplicata e os resultados expressos como média e erro padrão da média, utilizando nível de significância P<0,05. Os resultados obtidos demonstraram que tanto ocratoxina A como deoxinivalenol induziram proliferação linfocitária e baixa atividade de adenosina desaminase, enquanto zearalenona também induziu proliferação, mas nenhuma alteração na atividade da respectiva enzima. Quanto à avaliação da peroxidação lipídica, demonstrou-se a seguinte relação crescente de citotoxicidade: deoxynivalenol> ocratoxina A> zearalenona; enquanto que na avaliação da atividade de acetilcolinesterase esta relação foi inversamente proporcional. Este é o primeiro estudo in vitro realizado com ocratoxina A, deoxinivalenol e zearalenona sobre o cultivo primário de linfócitos de frangos de corte na avaliação desses parâmetros. / Poultry is one of the main targets of food contamination with mycotoxins. This contributes to the increase in the poultry industry losses due to problems such as high mortality, reduced body weight gain, change in feed conversion, immunosuppression, embryonic abnormalities and early embryonic death. Furthermore, the residual accumulation of mycotoxins in the meat is a public health concern. Various methods are used to assess the cytotoxicity induced by toxic agents, including inhibition of cellular growth, the evaluation of cell ability to synthesize macromolecules necessary for replication and the ability of this toxic agent to induce lipid peroxidation. Thus, the general objective of this study was to evaluate the in vitro effects of ochratoxin A, deoxynivalenol and zearalenone on the immune system of broiler chickens using as parameters, cell viability, enzymatic activity and oxidative stress. It was realized a primary culture of lymphocytes of birds and their isolation through density gradient centrifugation technique. Each mycotoxin has been added to the cell medium, at 80% confluence, at different concentrations (0.001, 0.01, 0.1 and 1 μg/ mL), analyzing cell viability, ecto-adenosine deaminase and acetylcholinesterase activity by colorimetric assays and lipid peroxidation through the malondialdehyde levels measured by thiobarbituric acid-reactive species test. All these parameters were evaluated at 24, 48 and 72 h, in triplicate and the results expressed as mean and standard error of the mean, using P<0.05 as significance level. The results showed that both ochratoxin A and deoxynivalenol induced lymphocyte proliferation and low adenosine deaminase activity, while zearalenone also induced proliferation, but no change in their enzyme activity. The assessment of lipid peroxidation demonstrated the following increasing cytotoxicity relation: deoxynivalenol>ochratoxin A>zearalenone; while in the evaluation of acetylcholinesterase activity this relationship was inversely proportional. This is the first in vitro study performed with ochratoxin A, deoxynivalenol and zearalenone on the primary culture of broiler chicken lymphocytes evaluating these parameters.

Aves domésticas são um dos principais alvos da contaminação alimentar com micotoxinas. O que contribui para o aumento dos prejuízos da indústria avícola devido a problemas como: alta mortalidade, redução do ganho de peso, alteração da conversão alimentar, imunossupressão, anormalidades embrionárias e morte embrionária precoce. Além disso, o acúmulo residual de micotoxinas na carne é uma preocupação da Saúde Pública. Diversos métodos são utilizados para a avaliação da citotoxicidade induzida por agentes tóxicos, incluindo a inibição do crescimento celular, a avaliação da capacidade celular de sintetizar macromoléculas necessárias para a replicação e da capacidade desse agente tóxico para induzir a peroxidação lipídica. Sendo assim, o objetivo geral do presente estudo foi avaliar os efeitos in vitro de ocratoxina A, deoxinivalenol e zearalenona sobre o sistema imunológico de frangos de corte, utilizando como parâmetros, a viabilidade celular, a atividade enzimática e o estresse oxidativo. Realizou-se cultivo primário de linfócitos das aves e o seu isolamento através da técnica de centrifugação por gradiente de densidade. Cada micotoxina foi adicionada ao meio celular, em uma confluência de 80%, em diferentes concentrações (0,001; 0,01; 0,1 e 1 μg/mL), analisando-se viabilidade celular, atividade de ecto-adenosina desaminase e acetilcolinesterase por ensaios colorimétricos e peroxidação lipídica através dos níveis de malondialdeído mensurados pela técnica de substâncias reativas ao ácido tiobarbitúrico. Todos esses parâmetros foram analisados em 24, 48 e 72 h, em triplicata e os resultados expressos como média e erro padrão da média, utilizando nível de significância P<0,05. Os resultados obtidos demonstraram que tanto ocratoxina A como deoxinivalenol induziram proliferação linfocitária e baixa atividade de adenosina desaminase, enquanto zearalenona também induziu proliferação, mas nenhuma alteração na atividade da respectiva enzima. Quanto à avaliação da peroxidação lipídica, demonstrou-se a seguinte relação crescente de citotoxicidade: deoxynivalenol> ocratoxina A> zearalenona; enquanto que na avaliação da atividade de acetilcolinesterase esta relação foi inversamente proporcional. Este é o primeiro estudo in vitro realizado com ocratoxina A, deoxinivalenol e zearalenona sobre o cultivo primário de linfócitos de frangos de corte na avaliação desses parâmetros. / Poultry is one of the main targets of food contamination with mycotoxins. This contributes to the increase in the poultry industry losses due to problems such as high mortality, reduced body weight gain, change in feed conversion, immunosuppression, embryonic abnormalities and early embryonic death. Furthermore, the residual accumulation of mycotoxins in the meat is a public health concern. Various methods are used to assess the cytotoxicity induced by toxic agents, including inhibition of cellular growth, the evaluation of cell ability to synthesize macromolecules necessary for replication and the ability of this toxic agent to induce lipid peroxidation. Thus, the general objective of this study was to evaluate the in vitro effects of ochratoxin A, deoxynivalenol and zearalenone on the immune system of broiler chickens using as parameters, cell viability, enzymatic activity and oxidative stress. It was realized a primary culture of lymphocytes of birds and their isolation through density gradient centrifugation technique. Each mycotoxin has been added to the cell medium, at 80% confluence, at different concentrations (0.001, 0.01, 0.1 and 1 μg/ mL), analyzing cell viability, ecto-adenosine deaminase and acetylcholinesterase activity by colorimetric assays and lipid peroxidation through the malondialdehyde levels measured by thiobarbituric acid-reactive species test. All these parameters were evaluated at 24, 48 and 72 h, in triplicate and the results expressed as mean and standard error of the mean, using P<0.05 as significance level. The results showed that both ochratoxin A and deoxynivalenol induced lymphocyte proliferation and low adenosine deaminase activity, while zearalenone also induced proliferation, but no change in their enzyme activity. The assessment of lipid peroxidation demonstrated the following increasing cytotoxicity relation: deoxynivalenol>ochratoxin A>zearalenone; while in the evaluation of acetylcholinesterase activity this relationship was inversely proportional. This is the first in vitro study performed with ochratoxin A, deoxynivalenol and zearalenone on the primary culture of broiler chicken lymphocytes evaluating these parameters.

Aves domésticas são um dos principais alvos da contaminação alimentar com micotoxinas. O que contribui para o aumento dos prejuízos da indústria avícola devido a problemas como: alta mortalidade, redução do ganho de peso, alteração da conversão alimentar, imunossupressão, anormalidades embrionárias e morte embrionária precoce. Além disso, o acúmulo residual de micotoxinas na carne é uma preocupação da Saúde Pública. Diversos métodos são utilizados para a avaliação da citotoxicidade induzida por agentes tóxicos, incluindo a inibição do crescimento celular, a avaliação da capacidade celular de sintetizar macromoléculas necessárias para a replicação e da capacidade desse agente tóxico para induzir a peroxidação lipídica. Sendo assim, o objetivo geral do presente estudo foi avaliar os efeitos in vitro de ocratoxina A, deoxinivalenol e zearalenona sobre o sistema imunológico de frangos de corte, utilizando como parâmetros, a viabilidade celular, a atividade enzimática e o estresse oxidativo. Realizou-se cultivo primário de linfócitos das aves e o seu isolamento através da técnica de centrifugação por gradiente de densidade. Cada micotoxina foi adicionada ao meio celular, em uma confluência de 80%, em diferentes concentrações (0,001; 0,01; 0,1 e 1 μg/mL), analisando-se viabilidade celular, atividade de ecto-adenosina desaminase e acetilcolinesterase por ensaios colorimétricos e peroxidação lipídica através dos níveis de malondialdeído mensurados pela técnica de substâncias reativas ao ácido tiobarbitúrico. Todos esses parâmetros foram analisados em 24, 48 e 72 h, em triplicata e os resultados expressos como média e erro padrão da média, utilizando nível de significância P<0,05. Os resultados obtidos demonstraram que tanto ocratoxina A como deoxinivalenol induziram proliferação linfocitária e baixa atividade de adenosina desaminase, enquanto zearalenona também induziu proliferação, mas nenhuma alteração na atividade da respectiva enzima. Quanto à avaliação da peroxidação lipídica, demonstrou-se a seguinte relação crescente de citotoxicidade: deoxynivalenol> ocratoxina A> zearalenona; enquanto que na avaliação da atividade de acetilcolinesterase esta relação foi inversamente proporcional. Este é o primeiro estudo in vitro realizado com ocratoxina A, deoxinivalenol e zearalenona sobre o cultivo primário de linfócitos de frangos de corte na avaliação desses parâmetros. / Poultry is one of the main targets of food contamination with mycotoxins. This contributes to the increase in the poultry industry losses due to problems such as high mortality, reduced body weight gain, change in feed conversion, immunosuppression, embryonic abnormalities and early embryonic death. Furthermore, the residual accumulation of mycotoxins in the meat is a public health concern. Various methods are used to assess the cytotoxicity induced by toxic agents, including inhibition of cellular growth, the evaluation of cell ability to synthesize macromolecules necessary for replication and the ability of this toxic agent to induce lipid peroxidation. Thus, the general objective of this study was to evaluate the in vitro effects of ochratoxin A, deoxynivalenol and zearalenone on the immune system of broiler chickens using as parameters, cell viability, enzymatic activity and oxidative stress. It was realized a primary culture of lymphocytes of birds and their isolation through density gradient centrifugation technique. Each mycotoxin has been added to the cell medium, at 80% confluence, at different concentrations (0.001, 0.01, 0.1 and 1 μg/ mL), analyzing cell viability, ecto-adenosine deaminase and acetylcholinesterase activity by colorimetric assays and lipid peroxidation through the malondialdehyde levels measured by thiobarbituric acid-reactive species test. All these parameters were evaluated at 24, 48 and 72 h, in triplicate and the results expressed as mean and standard error of the mean, using P<0.05 as significance level. The results showed that both ochratoxin A and deoxynivalenol induced lymphocyte proliferation and low adenosine deaminase activity, while zearalenone also induced proliferation, but no change in their enzyme activity. The assessment of lipid peroxidation demonstrated the following increasing cytotoxicity relation: deoxynivalenol>ochratoxin A>zearalenone; while in the evaluation of acetylcholinesterase activity this relationship was inversely proportional. This is the first in vitro study performed with ochratoxin A, deoxynivalenol and zearalenone on the primary culture of broiler chicken lymphocytes evaluating these parameters.

Philosophiae Doctor - PhD / Pesticides are designed to control or eliminate pests such as insects, rodents, weeds, bacteria, and fungi. They are used at a global scale for agricultural produce. Although pesticides play a significant role in increasing food production and eliminating diseases, exposure to pesticides may be harmful to non-target organisms. As a result concern over safety and esistance to pesticides has increased and there is pressure to reduce use and search for more environmentally and toxicologically safe and efficacious pesticides. Most pesticides currently in use are synthetic; therefore an alternative to synthetic pesticides is the use of naturally occurring products/ botanicals with pesticidal properties. Two plants indigenous to South African with pesticidal properties were chosen for this study. Dicerothamnus rhinocerotis (D. rhinocerotis) and Galenia africana (G. africana) have potential antifungal properties thus, may have potential use on agricultural produce as fungicides. Galenia africana and D. rhinocerotis extracts inhibit growth of B. cinerea (a fungal pathogen) at concentrations greater than 31.25 mg/ml and 125mg/ml respectively. A major consideration in approving pesticides for use is whether they pose an unreasonable risk to humans and to the environment. Toxicity studies are required to determine the safety of the plant extracts. The purpose of this study was to evaluate potential toxicity of ethanol extracts of D. rhinocerotis and G. africana, which is important when designing practices to reduce or eliminate excess exposure to them. Natural plant products with pesticidal properties could provide an alternative to synthetic pesticides and may thus effectively reduce resistance levels. This first objective of this study was to assess the cytotoxicity of D. rhinocerotis and G. africana on human cell cultures. Human whole blood and the human breast adenocarcinoma cell line (MCF-7) were treated with varying concentrations of the plant extracts and cytotoxicity determined. Cytotoxicity was measured using several biomarkers. Inhibiotory concentration for a 50% effect (IC50) and no observable effect level (NOEL) values were obtained for D. rhinocerotis and G. africana. The results showed that extracts of D. rhinocerotis and G. africana had cytotoxic effects on the cell cultures. The second objective of this study was to determine the ecotoxicity of D. rhinocerotis and G. africana. A series of acute toxicity tests, with effective concentration for a 50% effect (EC50) and lethal concentration for a 50% effect (LC50) as biomarkers, were conducted to estimate the potential environmental effect of the two plants. The tests were carried out using Vibrio fischeri, Selenastrum capricornutum, Daphnia pulex, and Poecilia reticulata as bioindicators. Results obtained showed that G. africana had higher toxicity units than D. rhinocerotis, thus showing that G. africana is more toxic to the aquatic species used as compared to D. rhinocerotis. The third objective of this study was to investigate the immunomodulatory effects of the two plant extracts. This was achieved by using mouse spleen cell cultures. Exposure of pesticides to the immune system may result in alteration of the normal immune functions. The cytokines IFN-γ and IL-4 were used as biomarkers to determine the T-cell activity of the immune system when exposed to the two botanical products. The results obtained showed that both D. rhinocerotis and G. africana decrease of the cytokines interferongamma (IFN-γ) and interleukin-4 (IL-4), thus may have immunotoxic effects. The fourth objective was to investigate the hepatotoxicity of the two plant extracts. Injury to the liver was investigated using a range of clinical biochemical tests that monitor liver enzyme activity and metabolic activity. Primary liver cell cultures were exposed to the plant products in question, after which the biochemical tests were carried out. The enzymes that were monitored were alanine aminotrasferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The results obtained showed that both of D. rhinocerotis and G. africana may have effects on the liver, as shown by the increased levels of enzymes released from cells upon exposure to plant extracts. The final objective of this study was to investigate the effect of the two plants on the male reproductive system. Injury to the male reproductive system was investigated using testicular cell cultures. Primary cell cultures were stimulated with luteinizing-hormone (LH) and exposed to the plant extracts. LH results in the production of testosterone, thus testosterone was used as a biomarker for assessing reproductive toxicity. The results obtained showed that both of D. rhinocerotis and G. africana have effects on the male reproductive system, as shown by the decreased testosterone secretion. Botanicals provide a simple, inexpensive and environmentally friendly (non-pollution and lesser toxicological concerns) alternative for pest control. However, motivation for the commercial use of botanicals as pesticides requires validating the efficacy of the plant as a pesticide, and also assessing its effects on human health and the environment. An important component of this evaluation involves toxicity studies, which enables cautions of dangerous practices and toxic effects of the plants to be issued. / South Africa