O projeto avaliou os efeitos da aflatoxina B1 (AFB1) e fumonisina B1 (FB1), isoladas e associadas, sobre a produtividade e a qualidade dos ovos de codornas poedeiras (Coturnix coturnix japonica). Duzentas e oitenta e oito aves, adquiridas com idade de 8 semanas, foram subdivididas em 6 grupos experimentais (48 aves por grupo) e submetidas a 6 tipos de tratamentos, constituídos por rações contendo AFB1 e FB1 nas concentrações: (0 AFB1+0 FB1), (0 AFB1+10 mg/kg FB1), (50 &microg/kg AFB1+0 FB1), (50 µg/kg AFB1+10 mg/kg FB1), (200 µg/kg AFB1+0 FB1), e (200 µg/kg AFB1+10 mg/kg FB1). As aves foram alimentadas durante 140 dias (5 ciclos de 28 dias). Os parâmetros de produtividade foram avaliados semanalmente, através do consumo de ração, peso dos ovos, índice de conversão alimentar e curva de produção. A qualidade dos ovos foi avaliada a cada ciclo de 28 dias, cada ovo produzido nesse dia foi analisado individualmente para a determinação do valor de unidade Haugh, gravidade específica e percentual do peso da casca. Ao final do 5º período experimental, o peso médio dos ovos foi significativamente menor (p < 0,05) nas aves alimentadas com 10 mg FB1/kg, 50 &microg/kg AFB1, 200 µg/kg AFB1 e com o tratamento de associação de 10 mg FB1/kg + 50 µg/kg AFB1. Em relação à produção de ovos, as codornas alimentadas com 10 mg FB1/kg apresentaram uma diminuição significativa (p < 0,05), ao final do 3º, 4º e 5º ciclos. O consumo médio diário de ração foi significativamente menor (p< 0,05) nas aves alimentadas com 10 mg FB1/kg, ao final do 4º e 5º ciclos, enquanto que os níveis de 50 ou 200 µg/kg AFB1 provocaram uma diminuição significativa (p < 0,05), ao final do 5º período experimental. Ao final do 1º, 2º e 5º ciclos, o consumo médio de ração foi significativamente menor (p< 0,05) nas aves tratadas com 10 mg FB1/kg + 50 µg/kg AFB1. Os índices de conversão alimentar e os valores de Unidades Haugh não foram afetados (p > 0,05) pelos tratamentos. A gravidade específica dos ovos foi significativamente menor (p < 0,05) ao final do 5º ciclo, nas aves tratadas com 10 mg FB1/kg + 200 µg/kg AFB1. Observou-se uma diminuição significativa (p < 0,05) na porcentagem do peso de casca, nas aves tratadas com 10 mg FB1/kg ao final do 1º ciclo, entretanto, houve um aumento significativo (p < 0,05) nos tratamentos com 200 µg/kg AFB1 e também com 10 mg/kg FB1 + 50 µg/kg AFB1 ao final do 1º ciclo. Já ao final do 5º ciclo, o aumento na porcentagem de peso de casca (p < 0,05) ocorreu somente nas aves tratadas com 10 mg/kg FB1 + 200 µg/kg AFB1. Os resultados demonstraram que a administração prolongada de FB1 e AFB1, isoladas ou associadas nos níveis utilizados no presente experimento, pode causar prejuízos econômicos aos produtores de ovos de codornas. / This study evaluated the individual and combined effects of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on egg quality and performance of laying Japanese quail (Coturnix coturnix japonica). Two hundred twenty-eight birds were purchased at 8 week of age and randomly distributed into 6 experimental groups and given rations containing AFB1 and FB1 at the following levels: (0 AFB1+0 FB1), (0 AFB1+10 mg/kg FB1), (50 &microg/kg AFB1+0 FB1), (50 &microg/kg AFB1+10 mg/kg FB1), (200 &microg/kg AFB1+0 FB1), e (200 &microg/kg AFB1+10 mg/kg FB1). The birds were fed for 140 days (5 28-day laying periods). Each treatment consisted of four replicates of twelve quail. Egg production and individual egg weight were checked daily. Feed consumption and feed utilization were determined weekly. Eggs laid in the last day of each 28-day laying period were collected and submitted to individual analysis for specific gravity, Haugh units and percent egg shell. Results showed that average egg weight at the end of the fifth cycle was significantly lower (p < 0,05) for groups fed 10 mg FB1/kg, 50 &microg/kg AFB1, 200 &microg/kg AFB1 and also for the group fed 10 mg FB1/kg + 50 &microg/kg AFB1. Average egg production significantly decreased (p < 0,05) for groups fed 10 mg FB1/kg by the end of the third, fourth and fifth cycles. Feed consumption was significantly lower (p < 0,05) for group exposed to 10 mg FB1/kg, by the end of fourth and fifth cycles, whereas birds fed 50 or 200 &microg/kg AFB1 showed a significant decrease (p < 0,05) on feed consumption, by the end of fifth cycle. Birds exposed to 10 mg FB1/kg + 50 &microg/kg AFB1 also showed lower values (p < 0,05) of feed consumption, by the end of first, second and fifth cycles. Feed utilization and Haugh units were not affected (p > 0,05) by AFB1 and FB1. Average egg specific gravity was significantly lower (p < 0,05) for group fed 10 mg FB1/kg + 200 &microg/kg AFB1, by the end of fifth cycle. Percent egg shell was significantly lower (p < 0,05) for group exposed to 10 mg FB1/kg, by the end of the first cycle, however, birds exposed to 200 &microg/kg AFB1 and also to 10 mg/kg FB1 + 50 &microg/kg AFB1, showed a significantly increase (p < 0,05) of percent egg shell, by the of the first cycle. Percent egg shell was significantly higher (p < 0,05) for group fed 10 mg/kg FB1 + 200 &microg/kg AFB1 , by the end of fifth cycle. The results obtained in the present study showed that the prolonged administration of FB1 and AFB1, singly or combined at the levels checked, may cause economic losses to the quail egg producers.

Mutação 249Ser no TP53 no Carcinoma Hepatocelular (CHC), frequente em países da África e Ásia, é uma evidência molecular de exposição à aflatoxina. O objetivo deste estudo é analisar a freqüência de 249Ser em 74 amostras de CHC no Brasil. A mutação foi analisada por RFLP e sequenciamento. A presença de vírus da hepatite B (VHB) foi analisada por PCR em tempo real. 249Ser foi encontrada em 13/74 (28%) e VHB em 13/74 (16%). A mutação foi encontrada em maior freqüência em tumores indiferenciados (OR = 2,415, IC = 1,001 - 5,824). O tamanho médio de tumores com 249Ser foi de 9,4 cm contra 5,5 cm de amostras sem a mutação (p=0,012). Não foi encontrada relação entre VHB e 249Ser. Os resultados indicam que 249Ser é um fator importante na carcinogênese do CHC no Brasil sendo associada à uma forma maior e menos diferenciada de tumor. / TP53 249Ser mutation has been proved a molecular evidence for aflatoxin-related Hepatocellular Carcinoma (HCC) and is frequent in Africa and Asia. The aim of our study was to analyze the frequency of 249Ser mutation in HCC from Brazil. We studied 74 samples of paraffin embedded HCC. 249Ser mutation was analyzed by RFLP and sequencing. Presence of HBV DNA was determined by Real-Time PCR. 249Ser was found in 21/74 (28%) samples while HBV DNA was found in 13/74 (16%). Poorly differentiated HCC was more likely to have 249Ser mutation (OR = 2.415, IC = 1.001 - 5.824). The mean tumor size of 249Ser HCC was 9.4 cm versus 5.5cm on wild type (p=0.012). HBV DNA was not related with 249Ser. Results indicate that 249Ser is an important factor of HCC carcinogenesis in Brazil and is associated with large and poorly differentiated tumors.

La mutation R249S (mutant p.R249S) du gène TP53, caractéristique de l'exposition à l'aflatoxine B1 (AFB1), est la plus fréquente dans les carcinomes hépatocellulaires (CHC) et est dans la plupart des cas associée à une infection chronique par le virus de l'hépatite B (VHB). En effet, il existe une synergie entre ces deux facteurs de risque, augmentant ainsi le risque de développer un CHC. Dans une première partie, nous avons étudié les mécanismes moléculaires de cette synergie dans différents modèles cellulaires puis dans une deuxième partie nous avons utilisé une approche épidémiologique pour étudier l'interaction entre la mutation R249S et le VHB. Nous avons tout d'abord montré que p.R249S avait perdu ses fonctions liées à p53wt. D'autre part, p.R249S était capable de former un complexe protéique avec l'oncoprotéine virale HBx dans les cellules de CHC PLC/PRF/5. Dans la deuxième partie de ce travail, nos résultats montrent que la mutation R249S est détectable dans l'ADN du sérum de sujets asymptomatiques de Gambie rurale (Afrique de l'Ouest). Notre travail met en évidence des variations temporelles quantitatives de la mutation R249S. Ces variations dépendent des niveaux d'exposition d'AFB1 mais également de la présence du VHB, suggérant une interaction entre l'AFB1 et le VHB. Enfin, dans une autre étude menée en Gambie et basée sur le recrutement de sujets ayant développés un CHC ou non (contrôles) nos résultats montrent que la mutation R249S est fortement associée au gène HBX complet dans les CHC. Cette association pourrait ainsi expliquer en partie l'effet synergique observé entre l'AFB1 et le VHB. A terme, une cible critique pourrait être identifiée pour des interventions préventives ou thérapeutiques précoces sur les CHC dans les régions de forte incidence / R249S mutation (mutant p.R249S) of TP53 gene, characteristic of the exposure to aflatoxin B1, is the most frequent TP53 mutation in hepatocellular carcinoma (HCC) and is highly associated with chronic hepatitis B virus infection (HBV). Indeed, a synergistic effect exists between these two main risk factors, thus increasing the risk to develop HCC. In a first part, we have studied the molecular mechanisms of this synergy in different cellular models and then, in a second part we have used an epidemiology-based approach to investigate the interaction between the R249S mutation and HBV. Firstly, we have shown that p.R249S has lost p53wt functions. Moreover, p.R249S formed a protein complex with the oncoprotein HBx from HBV in the HCC cell line PLC/PRF/5. In the second part, our results show that R249S mutation is detectable in plasma DNA of asymptomatic subjects from the rural Gambia (West Africa). Our work shows quantitative variations of R249S mutation that are dependent on the levels of exposition to AFB1 but also on the presence of HBV, suggesting an interaction between AFB1 and HBV. Finally, in another study performed in The Gambia and based on subjects with HCC or not (controls), our results show that R249S mutation is highly associated with HBX complete gene in HCC. Therefore this association could explain in part the synergistic effect observed between AFB1 and HBV. Eventually, a critical target may be identified for preventive or early therapeutic interventions on HCC of high-incidence regions

The studies described in this thesis investigated the relationship between DNA repair mechanisms, aflatoxin B1 (AFB1)-induced DNA damage and carcinogenesis. Mice deficient in 8-oxoguanine glycosylase (OGG1, the rate-limiting enzyme in repair of oxidized guanine), mice heterozygous for OGG1, and wild type mice, were exposed to a single tumourigenic dose (50 mg/kg) of AFB1. Neither ogg1 genotype nor AFB1 treatment affected levels of oxidized guanine in lung or liver 2 h post-treatment. ogg1 (-/-) mice had increased susceptibility to AFB1 toxicity, as reflected by increased mortality within one week of AFB1 exposure. AFB1 treatment did not significantly increase lung or liver tumourigenesis compared to DMSO controls. No difference was observed between ogg1 genotypes, although a non-significant trend towards AFB1-treated ogg1 (-/-) mice being more susceptible to tumourigenicity was apparent. Overall, deletion of ogg1 did not significantly affect AFB1-induced DNA damage or tumourigenicity, suggesting that oxidized guanine may not be a major contributor to AFB1-induced tumourigenesis. The effects of AFB1 on DNA repair were assessed in p53 (a protein implicated in regulation of DNA repair) wild type and heterozygous mice. p53 (+/+) mice treated with 0, 0.2 or 1.0 ppm AFB1 for 26 weeks had increased nucleotide excision repair (NER) activities in lung and liver compared to control, which may represent an adaptive response to AFB1-derived DNA adducts. In p53 (+/-) mice, the AFB1-induced increase in NER was significantly attenuated, suggesting that loss of one allele of p53 limits the ability of NER to up-regulate in response to AFB1-induced DNA damage. Twenty-six week exposure to AFB1 did not affect base excision repair (BER) in p53 (+/+) mouse lung or liver compared to control. BER was significantly decreased in livers from mice exposed to 1.0 ppm AFB1 compared to those exposed to 0.2 ppm AFB1, a result that was not due to liver cell death or to altered levels of OGG1 protein. In lungs and livers of p53 (+/-) mice, BER activity was unchanged by AFB1. As such, the difference in BER response between 0.2 ppm and 1.0 ppm AFB1 treatment seen in the p53 (+/+) mice appears to be p53 dependent. / Thesis (Ph.D, Pharmacology & Toxicology) -- Queen's University, 2013-10-17 22:24:31.577

Dans les pays d’Afrique Sub-Saharienne et d’Asie du Sud-Est, l’infection chronique par le virus de l’hépatite B (VHB) et l’exposition à l’aflatoxine B1 (AFB1) ont un rôle synergique dans le développement du carcinome hépatocellulaire (CHC). Cependant les mécanismes impliqués ne sont pas élucidés à ce jour. Le VHB est un petit virus à ADN qui induit différentes maladies du foie allant du portage asymptomatique au CHC. L’AFB1 est une mycotoxine qui contamine la nourriture. Après activation en époxyde, elle forme des adduits à l’ADN puis des mutations, dont la mutation au codon 249 du gène suppresseur de tumeur TP53 (AGG → AGT, mutation R249S). Nous avons utilisé les caractéristiques uniques de la lignée cellulaire HepaRG pour étudier les interactions entre le VHB et l’AFB1 : ces cellules se différencient in vitro en hépatocytes qui métabolisent l’AFB1 et peuvent être infectés par le VHB. Nous avons montré que l’AFB1 induit une réponse de p53 dose-dépendante et agit comme un agent antiviral en réprimant la production de particules virales après 48h d’exposition. D’autre part, l’infection par le VHB n’a montré aucun effet sur la formation ou la réparation des adduits. De la réparation et de la prolifération cellulaire ont été observées suite au traitement à l’AFB1, suggérant la faisabilité de l’étude de mutations dans ce système, dont R249S. Ces résultats suggèrent que l’AFB1 atténue l’hépatite chronique tout en maintenant les hépatocytes sous intense pression mutagène, ce qui favoriserait la progression vers le CHC / In sub-Saharan Africa and South-East Asia, chronic infection by hepatitis B virus (HBV) and exposure to aflatoxin B1 (AFB1) play a synergic role in the development of hepatocellular carcinoma (HCC). However mechanisms are still largely unknown. HBV is a small DNA virus which induces different liver diseases from asymptomatic carriage to HCC. AFB1 is a mycotoxin which contaminates food. After activation into an epoxide, it forms DNA adducts and mutations, such as R249S mutation at codon 249 in tumor suppressor TP53 gene (AGG → AGT). We have taken advantage of the unique features of the cell line HepaRG to investigate interactions between both risk factors: cells differentiate in vitro into hepatocytes which metabolize AFB1 and can be infected by HBV. We have shown that AFB1 induces a dose-dependent p53 response and act as an antiviral agent by repressing production of HBV particles after 48 hours of exposure. Nevertheless HBV infection had no effect on adduct formation or repair. Moreover DNA synthesis activity associated to DNA repair and cell proliferation were observed following AFB1 treatment, suggesting the feasibility of mutation research in this model, especially R249S. Overall these results suggest that AFB1 may attenuate HBV chronic hepatitis while maintaining hepatocytes under intense mutagenic pressure, thus enhancing the progression towards HCC

Student Number : 9902006N - MSc(Med) Dissertation - School of Medicine - Faculty of Health Sciences / Hepatocellular carcinoma (HCC) is the most common primary malignant tumour of the liver. Aflatoxin B1 (AFB1) is a potent hepatocarcinogen, and dietary iron overload has been shown to contribute to HCC development in black africans. Both are well studied hepatotoxins. The aim of this study was to use a Wistar rat model over a 12 month period to investigate synergy and the extent thereof between AFB1 ingestion and dietary iron overload. 25ug/day of AFB1, reconstituted in DMSO, was administered by gavaging the animals, over a period of 10 days with a 2 day interval in between. The chow diet was supplemented with 0.75% (w/w) ferrocene iron. Experimental subjects were divided into 4 groups. Group 1 was fed the normal chow diet. Group 2 was fed 0.75% (w/w) ferrocene iron alone. Group 3 was gavaged 250μg AFB1 alone. Group 4 was fed the 0.75% (w/w) ferrocene iron and gavaged 250μg AFB1. A number of assays were conducted to investigate synergy. Colorimetric assays were used to measure serum iron, total-iron binding capacity, ALT, AST, GGT, nitrite production, lipid peroxidation and hydroxyproline concentrations. ELISA’s were used to determine ferritin, 8-isoprostane and 8-hydroxyguanosine concentrations. Nontransferrin bound iron was measured using an HPLC method. A chemiluminescent assay was used to measure superoxide anion production. Cytokines were measured using a suspension array system. Mutagenicity was assessed using the Ames mutagenicity assay using salmonella typhimirium strains TA97, TA98, TA100 and TA102. Iron profiling indicated that iron overloading occurred with the ingestion of the ferrocene diet. Biomarkers of oxidative stress, as illustrated by the measurement of 8-hydroxyguanosine and lipid peroxidation, showed additive synergistic effects between the two carcinogens. The anti-inflammatory interleukin-10 was shown to be markedly elevated with the co-administration of the two carcinogens, indicating the elevated inflammatory processes. Additive synergistic effects were noted in terms of the liver disease marker ALT. The salmonella typhimirium strain TA102 used in the Ames mutagenicity test showed increased colony counts with respect to the coadministration of carcinogens (P<0.05), although no synergistic effect was noted. In a few of the presented parameters, the AFB1 group was not significantly different to the control group, although significant differences between the Fe group and the Fe + AFB1 groups were noted. The implication of which is that the presence of AFB1 is increasing the activity of Fe as a carcinogen, thereby acting as a co-carcinogen. Examples of such parameters illustrating this are presented in the results section including serum ALT, serum nitrite, liver and serum lipid peroxidation, liver and serum 8-hydroxyguanosine, some of the mutagenicity assays, and interleukin-10. The conclusion of this study suggests that AFB1 acts as a co-carcinogen in the presence of iron overloading, implying that a synergistic relationship between these two toxins exists.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-24T13:37:53Z No. of bitstreams: 1 2011- Veronica da Silva Cardoso.pdf: 2067813 bytes, checksum: a52c401412243d162e7030dda12cdf48 (MD5) / Made available in DSpace on 2016-08-24T13:37:53Z (GMT). No. of bitstreams: 1 2011- Veronica da Silva Cardoso.pdf: 2067813 bytes, checksum: a52c401412243d162e7030dda12cdf48 (MD5) Previous issue date: 2011-04-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Piperine interference (amide extracted from black pepper) added to the diet of broiler chickens experimentally intoxicated by aflatoxin B1 (mycotoxin of great importance in the poultry sector) and it?s chemoprotective capacity were the main goal of this work. The experiment was divided into two assays: (i) The first assay was carried out to determine the effects of different concentrations of piperine (0, 60, 120, 180 ppm) and it?s possible toxicity in broiler chickens diets. Ninety six male chicks (Cobb), seven days old were used, being randomly allocated into four experimental groups (n=24) during 35 consecutive days. The following parameters were evaluated: biochemical, hematological, histopathological (proventriculus, gizzard, liver, kidney), histomorphometric (small intestine) and zootecnic. The concentration of 60 ppm of piperine in the diet was safe for broilers, showing better performance of broilers on period from 36 to 42 days old. The concentration of 180 ppm caused leukopenia and concentrations of 120 and 180 ppm was observed decrease in the number of heterophils and monocytes. Hepatotoxicity was observed by elevated AST enzyme activity, histopathological changes and decreased absorption surface in the segments (jejunum and ileum) of small intestine were observed for both 120 and 180 ppm concentrations. (ii) In the second assay, 60 broilers with nine days old divided into four groups: control, piperine (60 ppm added to diet), aflatoxin B1 (0.5 mg of aflatoxin B1.Kg-1 of body weight, orally) and piperine associated aflatoxin B1, were evaluated by effect chemoprotector of piperine against toxics effects of aflatoxin B1 being evaluated for zootecnic, biochemical, histopathological and histomorphometric parameters, toxic heterophils in peripheral blood and genotoxic by comet assay and micronucleus were also determined. No changes in the performance parameters were observed after this experiment. Broiler chickens intoxicated with AFB1 (0.5 mg of aflatoxin B1.kg-1 of body weight ) showed: decreased body weight gain and increased feed conversion; reduced carcass and cuts yields; liver toxicity, with increased relative weight of the liver and heart, macroscopic variations of hepatic parenchyma and increase of liver enzymes activity; kidney enzymes increase without evidence of renal tissue damage macroscopic or microscopic; leukopenia with significant reduction of lymphocytes and heterophils; reduction in absorptive surface due to the reduction of the length and width of the villi of all studied segments of small intestine; presence of toxic heterophils. The cytotoxic and genotoxic effects of aflatoxin B1 described above were significantly reduced or absent in the group of broiler intoxicated with aflatoxin B1 and fed with with piperine. No significant difference between piperine associated aflatoxin B1 in control and piperine groups were observed. The addition of 60 ppm of piperine in the diet of broiler chickens was safe, promoting beneficial effect both in zootecnic parameters and in poultry health, preventing toxic effects of aflatoxin B1in broiler chickens. / A interfer?ncia da piperina (amida extra?da da pimenta do reino) adicionada ? ra??o de frangos de corte intoxicados experimentalmente por aflatoxina B1 (micotoxina de grande relev?ncia no setor av?cola) e sua capacidade quimioprotetora foram o principal objetivo deste trabalho. O experimento foi dividido em dois ensaios: (i) O primeiro ensaio foi realizado para determinar os efeitos de diferentes concentra??es de piperina (0, 60, 120 e 180 ppm) foram avaliados e sua poss?vel toxicidade. Noventa e seis pintos (Cobb), com 7 dias de idade foram divididos aleatoriamente em 4 grupos (n=24), por 35 dias consecutivos. Os par?metros avaliados foram: hematol?gicos, bioqu?micos, histopatol?gicos (proventr?culo, moela, f?gado e rim), histomorfom?trico (intestino delgado) e par?metros zoot?cnicos. A concentra??o de 60 ppm de piperina adicionada ? ra??o foi segura para frangos de corte, tendo ainda resultado em melhor desempenho dos frangos na fase final (36-42 dias de idade). A concentra??o de 180 ppm promoveu leucopenia e nas concentra??es de 120 e 180 ppm foi observada diminui??o do n?mero de heter?filos e mon?citos; hepatotoxicidade, com eleva??o da enzima AST e altera??es histopatol?gicas em ambas as concentra??es; diminui??o da superf?cie de absor??o nos segmentos (jejuno e ?leo) do intestino delgado, por?m, sem altera??o dos par?metros zoot?cnicos. (ii) Para o segundo ensaio com a concentra??o de 60ppm de piperina: 60 frangos com 9 dias de idade, foram divididos em 4 grupos (n=15): grupo controle, grupo aflatoxina B1 (0,5 mg aflatoxina B1.kg-1 de peso vivo por via oral), grupo piperina (60 ppm adicionada ? ra??o) e grupo piperina associada a aflatoxina B1, determinando-se a capacidade quimioprotetora da piperina sendo avaliados os par?metros zoot?cnicos, hematol?gicos, bioqu?micos, histopatol?gicos, histomorfom?tricos, os efeitos genot?xicos da aflatoxina B1 pelo teste do cometa e do micron?cleo, presen?a de heter?filos t?xicos no sangue perif?rico. Os frangos intoxicados com aflatoxina B1 (0,5 mg de aflatoxina B1.Kg-1 de peso vivo) apresentaram: diminui??o do ganho m?dio de peso e piora da convers?o alimentar; diminui??o do rendimento de carca?a e cortes; hepatotoxicidade, com aumento de peso relativo do f?gado e cora??o, varia??es macrosc?picas do par?nquima hep?tico e eleva??o das enzimas hep?ticas; aumento das enzimas renais, sem evid?ncia de les?es macrosc?picas e microsc?picas no tecido renal; leucopenia, com diminui??o significativa de linf?citos e heter?filos; diminui??o da superf?cie de absor??o em fun??o da redu??o do comprimento e largura das vilosidades de todos os segmentos estudados do intestino delgado; presen?a de heter?filos t?xicos. Os efeitos citot?xicos e genot?xicos da aflatoxina B1 foram significativamente reduzidos ou ausentes no grupo piperina associada a aflatoxina B1, sem diferen?a significativa entre o grupo controle e piperina. A ra??o de frangos de corte com 60 ppm de piperina foi segura, promovendo efeito ben?fico tanto nos par?metros zoot?cnicos avaliados, como na sanidade av?cola, por impedir os efeitos t?xicos da aflatoxina B1 em frangos de corte.

Šis mokslinis darbas buvo atliktas Justinas Banelis Lietuvos sveikatos mokslų universitete. Vadovaujant prof. dr . Broniui Bakučiui konsultuojant lekt. dr. Violetai Baliukonienei. Šio tyrimo tema " Mikotoksinus detoksikuojančių profilaktikos priemonių pieniniams galvijams efektyvumo įvertinimas " . Puslapių skaičius 37 , 10 lentelių , 3 nuotraukos . Tyrimai buvo atlikti nuo 01/10/2011 iki 01/10/2012 LSMU VA ir gyvūnų gerovės laboratorijoje. Šio tyrimo tikslas buvo Įvertinti mikotoksinus detoksikuojančio preparato efektyvumą pieninių galvijų bandos sveikatingumui. Biocheminių , kraujo tyrimų parametrų ir pieno sudėties melžiamų karvių ir nustatyti mikotoksinu detoksikacija su komerciniu X adsorbentu. Buvo atrinktos 28 Lietuvos Žalosios veislės kliniškai sveikos vidutinio produktyvumo karvės. Karvės buvo nuo 3,43 ± 0,24 laktacijos trukmės laktacijos buvo 122 ± 15,9 dienų. Pieno išeiga karvės buvo 15,36 kg per dieną ,pieno riebalų vidurkis buvo 4,14 ± 0,25 % , baltymų kiekis 3,06 ± 0,04 % ir karbamido - 23,80 ± 1,35 mg% . Karvių pašarams buvo nustatytas mikotoksinų aflatoksino B1 ( AFL B1) , zearalenono ( ZON ), deoksinivalenolio ( DON ). Zearalenonas buvopagrindinis teršalas ir buvo rasta šiene iki 1000 mikrogramų / kg sausos medžiagos. Deoksinivalenolis buvoantras teršalų ir buvo rasta šieno lygiu iki 600 mikrogramų / kg sausos medžiagos. Didžiausias aflatoksino B1 koncentraciją - 10,0 mikrogramo / kg žemės miežių . Komercinis detoksikuojantis produktas X buvo duotas... [toliau žr. visą tekstą] / This scientific work was done by student Justinas Banelis of Lithuanian University of Health Sciences. He was supervised by prof. dr. Bronius Bakutis and consulted by lect. dr. Violeta Baliukoniene. The topic of this scientific research is “The effects of feeding mycotoxin binding products on the performance of lactating dairy cows“. Page count 37, 10 tables,3 pictures. The experiments was done from 01/10/2011 to 01/10/2012 in LUHS VA in the Animal Welfare Reaserch Laboratory. The aim of this study were to investigate the long-term exposure toxic effects of diet naturally contaminated with a low concentrations mycotoxins (AFL B1, ZON, DON) on biochemical, complete blood count parameters and milk composition of dairy cows and to determined the mycotoxins detoxification by with the commercial X adsorbent. 28 Lithuanian Red clinically healthy medium productive cows were selected. Cows were from 3.43±0.24 lactation and duration of lactation were 122±15.9 days. Milk-yield of cow was 15.36 kg per day, an average of milk fat was 4.14 ±0.25 %, protein content 3.06±0.04 % and urea – 23.80±1.35 mg %. In cow feeds were determined mycotoxins aflatoxin B1 (AFL B1), zearalenone (ZON), deoxynivalenol (DON). Zearalenone was the major contaminant and was found in the hay at level of up to 1000 µg/kg of dry matter. Deoxynivalenol was the second contaminant and was found in the hay at level of up to 600 µg/kg of dry matter. The biggest Aflatoxin B1 content - 10.0 µg/kg in ground barley. The... [to full text]

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aflatoxin B1 (AFB1) is one of the main mycotoxins that can be identified in foods, and has relevance for agricultural economics and public health because of its immunotoxic properties. A functional immune system is a basic requirement for a healthy life in modern animal production. The interaction involving nutrition and immunity is a strategic factor to obtain a high quality performance in the poultry industry. Immunomodulators such as β-glucans have an immunostimulating activity, which enables the host ability to resist opportunistic infections. To contribute to the elucidation of the mechanism of action of β-glucans in broiler chicken lymphocytes, the effects of the concentrations of 0.1, 1 and 10% of β-glucans derived from Saccharomyces cerevisiae were investigated in lymphocytes exposed to increasing concentrations of AFB1 (0, 0.1, 1, 10, 20 μg/ml). Lymphocytes were separated by Ficoll-Histopaque density and cultured in 96 well-plates containing AFB1 and/or β-glucans in a 5% CO2 atmosphere at 39°C. MTT, PicoGreen® and 2'-7'-dichlorofluorescein diacetate cytotoxicity tests were evaluated at 24, 48 and 72 h of incubation. The comet assay to elucidate the DNA damage was also performed. The percentage of viable cells decreased in the presence of 10 μg/ml AFB1 at 48 h (p < 0.05) and 10 and 20 μg/ml AFB1 at 72 h (p < 0.001 and p < 0.01, respectively), when compared to the control group (0 μg/ml). Furthermore, an increase in cell-free DNA in AFB1 concentrations > 1 μg/ml (p < 0.001) and the generation of ROS at 24 h were also observed. DNA damage increased approximately 2.3 fold in lymphocytes exposed to 20 μg/ml of AFB1 when compared to the control group. Conversely, β-glucans showed cytoprotective effects (p < 0.001), and the concentration of 1% reverted the AFB1-induced lymphocyte damage. β-glucans at 10% significantly increased (p < 0.001) the formation of reactive oxygen species (ROS), potentiating the AFB1-induced ROS formation. In conclusion, this study showed that AFB1 and β-glucans exert influence on lymphocyte oxidative metabolism and have dose-dependent potentiating effects. The results also showed genoprotective in vitro effect of β-glucans in poultry lymphocytes exposed to AFB1, being the concentration of 1% β-glucans able to maintain DNA integrity. / A aflatoxina B1 (AFB1) é uma das principais micotoxinas que podem ser identificadas em alimentos, possuindo relevância agroeconômica e para a saúde pública, por ser considerada imunotóxica. Um sistema imune funcional é um requisito básico para uma vida saudável na produção moderna de animais. A interação envolvendo nutrição e imunidade é um fator estratégico para obter um bom desempenho em frangos de corte. Devido as suas atividades imunomodulatórias, substâncias como as β-glucanas proporcionam ao hospedeiro uma maior capacidade de resistir a infecções oportunistas. Para melhor compreender o mecanismo de ação das β-glucanas, sobre os linfócitos de frangos de corte, investigou-se os efeitos das concentrações de 0.1, 1 e 10% de β-glucanas derivadas do fungo Saccharomyces cerevisiae em linfócitos expostos a crescentes concentrações de AFB1 (0, 0.1, 1, 10, 20 μg/ml). Os linfócitos foram separados através do reagente de densidade Ficoll-Histopaque e cultivados em placas de 96 poços, contendo as concentrações de AFB1 e/ou β-glucanas em atmosfera de 5% de CO2 a 39°C durante 24, 48 e 72 h. A citotoxicidade celular foi avaliada através dos testes MTT e PicoGreen®, e a formação de espécies reativas de oxigênio (EROS) através do ensaio 2′-7′- diacetato diclorofluoresceína. Também foi utilizado o teste cometa para elucidar os danos ao DNA. A viabilidade celular reduziu na presença de 10 μg/ml de AFB1 em 48 h (p < 0.05) e em 10 and 20 μg/ml de AFB1 (p < 0.01 e p < 0.001, respectivamente) em 72 h quando comparada ao grupo controle. Além disso, as concentrações de AFB1 > 1 μg/ml aumentaram significativamente (p < 0.001) a liberação de fita dupla de DNA (dsDNA) e a produção de EROS em 24 h. Os danos causados ao DNA foram confirmados através do momento cauda do cometa e aumentaram cerca de 2,3 vezes em linfócitos expostos a 20 μg/ml de AFB1 quando comparados ao grupo controle. Por outro lado, as β-glucanas exerceram efeitos citoprotetores (p < 0.001), sendo que a concentração de 1% foi capaz de reverter os danos genotóxicos causados pela ação da AFB1. Já a concentração de 10% de β-glucanas aumentou significativamente (p < 0.001) a formação de EROS, potencializando a ação da AFB1. Em conclusão, este estudou evidenciou que a AFB1 e as β-glucanas exercem influência sobre o metabolismo oxidativo dos linfócitos e possui efeito potencializador dose-dependente. Os resultados também evidenciaram o efeito genoprotetor in vitro de β-glucanas em linfócitos de frangos expostos a AFB1, sendo a concentração de β-glucanas a 1% capaz de manter a integridade do DNA.

Grace S.N. Lau. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 335-362). / List of Abbreviations --- p.i / Abstract --- p.1 / Chapter Chapter 1 --- General Introduction and Study Objectives / Chapter 1.1 --- Metabolic activation - role in drug toxicity and carcinogenesis --- p.5 / Chapter 1.2 --- Hepatocellular carcinoma --- p.12 / Chapter 1.2.1 --- Epidemiology --- p.12 / Chapter 1.2.2 --- Aetiological factors --- p.17 / Chapter 1.2.2.1 --- Hepatitis B virus infection --- p.17 / Chapter 1.2.2.2 --- Cirrhosis --- p.24 / Chapter 1.2.2.3 --- Aflatoxins --- p.25 / Chapter 1.2.2.4 --- Other factors --- p.26 / Chapter 1.2.2.5 --- Summary --- p.29 / Chapter 1.3 --- Study objectives --- p.30 / Chapter Chapter 2 --- The Metabolism of Paracetamol in Healthy Subjects andin Patients with Liver Disease and Hepatocellular Carcinoma / Chapter 2.1 --- Introduction --- p.34 / Chapter 2.1.1. --- History of paracetamol --- p.34 / Chapter 2.1.2 --- Pharmacology of paracetamol --- p.37 / Chapter 2.1.3 --- "Absorption, Distribution, Metabolism and Excretion" --- p.38 / Chapter 2.1.3.1 --- Absorption --- p.38 / Chapter 2.1.3.2 --- Distribution --- p.41 / Chapter 2.1.3.3 --- Metabolism --- p.42 / Chapter 2.1.3.4 --- Excretion --- p.57 / Chapter 2.1.4 --- Toxicity and Overdosage --- p.59 / Chapter 2.2 --- Estimation of paracetamol and its metabolites in plasma and urine by high performance liquid chromatography --- p.72 / Chapter 2.2.1 --- Introduction --- p.72 / Chapter 2.2.2 --- Analytical method --- p.76 / Chapter 2.2.2.1 --- Materials --- p.76 / Chapter 2.2.2.2 --- Instrumentation --- p.77 / Chapter 2.2.2.3 --- Collection and storage of samples --- p.79 / Chapter 2.2.2.4 --- Chromatographic conditions --- p.79 / Chapter 2.2.3 --- Urine assay --- p.79 / Chapter 2.2.3.1 --- Preparation of standards and test samples for urine assay --- p.79 / Chapter 2.2.3.2 --- Calculation of results for urine assay --- p.80 / Chapter 2.2.3.3 --- Results of urine assay --- p.81 / Chapter 2.2.3.4 --- Validation of urine assay --- p.81 / Chapter 2.2.4 --- Plasma assay --- p.83 / Chapter 2.2.4.1 --- Preparation of standards and test samples for plasma assay --- p.83 / Chapter 2.2.4.2 --- Calculation of results for plasma assay --- p.91 / Chapter 2.2.4.3 --- Results of plasma assay --- p.91 / Chapter 2.2.4.4 --- Validation of plasma assay --- p.93 / Chapter 2.2.5 --- Summary --- p.99 / Chapter 2.3 --- The pharmacokinetics of paracetamol in healthy subjects --- p.103 / Chapter 2.3.1 --- Introduction --- p.103 / Chapter 2.3.2 --- Study protocol --- p.103 / Chapter 2.3.3 --- Methods --- p.103 / Chapter 2.3.3.1 --- Subjects --- p.103 / Chapter 2.3.3.2 --- Drug administration and sampling --- p.104 / Chapter 2.3.3.3 --- Drug analysis --- p.108 / Chapter 2.3.3.4 --- Calculations --- p.108 / Chapter 2.3.4 --- Pharmacokinetic analysis --- p.109 / Chapter 2.3.5 --- Statistical analysis --- p.113 / Chapter 2.3.6 --- Results --- p.114 / Chapter 2.3.6.1 --- Plasma Results --- p.114 / Chapter 2.3.6.2 --- Urine Results --- p.118 / Chapter 2.3.6.3 --- Pharmacokinetic Results --- p.125 / Chapter 2.3.6.4 --- Statistical Results --- p.134 / Chapter 2.3.7 --- Discussion --- p.145 / Chapter 2.4 --- "The pharmacokinetics of paracetamol in healthy subjects, patients with liver disease and hepatocellular carcinoma" --- p.155 / Chapter 2.4.1 --- Introduction --- p.155 / Chapter 2.4.2 --- Study protocol --- p.156 / Chapter 2.4.3 --- Methods --- p.156 / Chapter 2.4.3.1 --- Subjects --- p.156 / Chapter 2.4.3.2 --- Drug administration and sampling --- p.157 / Chapter 2.4.3.3 --- Drug analysis --- p.160 / Chapter 2.4.3.4 --- Calculations --- p.160 / Chapter 2.4.4 --- Pharmacokinetic analysis --- p.161 / Chapter 2.4.6 --- Results --- p.162 / Chapter 2.4.6.1 --- Plasma Results --- p.162 / Chapter 2.4.6.2 --- Urine Results --- p.162 / Chapter 2.4.6.3 --- Pharmacokinetic Results --- p.179 / Chapter 2.4.7 --- Discussion --- p.194 / Chapter 2.4.8 --- Summary --- p.203 / Chapter Chapter 3 --- Metabolic Activation of Aflatoxin B1 in Healthy Subjects and in Patients with Liver Disease and Hepatocellular Carcinoma / Chapter 3.1 --- General introduction --- p.206 / Chapter 3.1.1 --- Chemical structures and properties --- p.207 / Chapter 3.1.2 --- Contamination of food by aflatoxins --- p.209 / Chapter 3.1.3 --- Metabolism of aflatoxins --- p.210 / Chapter 3.1.4 --- Human diseases possibly related to exposure to aflatoxins --- p.226 / Chapter 3.1.4.1 --- Acute aflatoxicosis --- p.226 / Chapter 3.1.4.2 --- Reye's syndrome --- p.227 / Chapter 3.1.4.3 --- Kwashiorkor --- p.228 / Chapter 3.1.4.4 --- Impaired immune function --- p.229 / Chapter 3.1.4.5 --- Hepatocellular carcinoma --- p.230 / Chapter 3.1.5 --- Biochemical and molecular epidemiology of aflatoxins --- p.232 / Chapter 3.2 --- Development of an ELISA method to monitor AFB1 exposure in human serum --- p.237 / Chapter 3.2.1 --- Introduction --- p.237 / Chapter 3.2.2 --- Preparation of all the components necessary for analysing AFB1-albumin adducts by ELISA --- p.243 / Chapter 3.2.2.1 --- Materials --- p.243 / Chapter 3.2.2.2 --- Preparation of rabbit AFB1 antiserum --- p.244 / Chapter 3.2.2.3 --- Preparation of the rat monoclonal antibody --- p.244 / Chapter 3.2.2.4 --- Concentration of cell culture supernatant by ammonium sulphate precipitation --- p.246 / Chapter 3.2.2.5 --- Preparation of the BSA-AFB1 conjugate --- p.248 / Chapter 3.2.2.6 --- Preparation of the immunoaffinity gel --- p.250 / Chapter 3.2.2.7 --- Preparation of the ELISA plates --- p.251 / Chapter 3.2.3 --- General procedures used in the analysis of AFB1- albumin adducts --- p.252 / Chapter 3.2.3.1 --- Competitive ELISA binding assay --- p.253 / Chapter 3.2.3.2 --- Sep-pak C18 cartridge --- p.254 / Chapter 3.2.3.3 --- Immunoaffinity column --- p.255 / Chapter 3.2.3.4 --- Evaporation process --- p.255 / Chapter 3.2.3.5 --- HPLC --- p.256 / Chapter 3.2.3.6 --- Radioactive counting --- p.256 / Chapter 3.2.3.7 --- Albumin isolation --- p.257 / Chapter 3.2.3.8 --- Digestion of albumin --- p.257 / Chapter 3.2.3.9 --- Animal procedures --- p.258 / Chapter 3.2.4 --- Validations --- p.259 / Chapter 3.2.4.1 --- Analysis of standard AFB1 and AFB1- lysine in ELISA --- p.259 / Chapter 3 2.4.2 --- Optimisation of antiserum dilution and concentration of coating antigenin ELISA --- p.259 / Chapter 3 2.4.3 --- Elution characteristics and capacity of the immunoaffinity column --- p.261 / Chapter 3.2.4.4 --- Comparison of immunoaffinity gels prepared with different affinity gels --- p.261 / Chapter 3.2.4.5 --- Immunoaffinity column experiment of AFB1-lysine --- p.263 / Chapter 3.2.4.6 --- HPLC Analysis of fractions from immunoaffinity column --- p.263 / Chapter 3.2.4.8 --- HPLC analysis of fractions from Sep- Pak C18 cartridge --- p.264 / Chapter 3.2.4.9 --- Digestion of serum albumin by proteinase K --- p.264 / Chapter 3.2.4.10 --- Effect of ethanol in samples to be loaded onto Sep-Pak C18 cartridge --- p.265 / Chapter 3.2.4.11 --- Effect of drying in a vacuum concentrator on recovery of radioactivity of 3H-AFB1 --- p.266 / Chapter 3.2.4.12 --- Evaluation of the overall procedure for the analysis of serum albumin adducts of AFB1 --- p.267 / Chapter 3.2.4.13 --- HPLC analysis of samples obtained after digestion and all clean-up procedures --- p.268 / Chapter 3.2.5 --- Results and discussion --- p.268 / Chapter 3.2.5.1 --- BSA-AFB1 conjugate --- p.268 / Chapter 3.2.5.2 --- Treatment of experimental animals with 3H-AFB1 --- p.270 / Chapter 3.2.5.3 --- Optimisation of antiserum dilution and concentration of coating antigenin ELISA --- p.272 / Chapter 3.2.5.4 --- Analysis of standard AFB1 and AFB1- lysine in ELISA --- p.275 / Chapter 3.2.5.5 --- Sep-Pak C18 cartridge - elution characteristics and capacity --- p.279 / Chapter 3.2.5.6 --- Elution characteristics of immunoaffinity columns --- p.282 / Chapter 3.2.5.7 --- Immunoaffinity column experiment of AFB1-lysine --- p.290 / Chapter 3.2.5.8 --- Digestion of serum albumin by proteinase K --- p.295 / Chapter 3.2.5.9 --- Effect of ethanol in samples to be applied onto Sep-Pak C18 cartridges --- p.297 / Chapter 3.2.5.10 --- Recovery of radioactivity after dryingin a vacuum concentrator --- p.300 / Chapter 3.2.5.11 --- Recovery of the overall clean-up procedure for the analysis of serum albumin adducts of AFB1 --- p.300 / Chapter 3.2.5.12 --- HPLC analysis of samples obtained after all clean-up procedures --- p.305 / Chapter 3.2.5.13 --- The use of rabbit anti-AFB1 anti-serum and rat anti-AFB1 monoclonal antibody --- p.308 / Chapter 3.2.6 --- Summary --- p.309 / Chapter 3.3 --- Monitoring of AFBralbumin adducts in plasma of patients with liver disease and hepatocellular carcinoma --- p.311 / Chapter 3.3.1 --- Introduction --- p.311 / Chapter 3.3.2 --- Material and methods --- p.314 / Chapter 3.3.2.1 --- Subject --- p.314 / Chapter 3.3.2.2 --- Sample collections --- p.315 / Chapter 3.3.2.4 --- Assay for AFB1-albumin adducts --- p.315 / Chapter 3.3.2.5 --- Statistical analysis --- p.318 / Chapter 3.3.3 --- Results and discussion --- p.318 / Chapter Chapter 4 --- Summary and Ideas for Further Studies --- p.330 / Acknowledgements --- p.333 / References --- p.335 / Appendices --- p.364