Identification of toxigenic Aspergillus species from diet dairy goat using a polyphasic approach / Identificação de espécies toxigênicas de Aspergillus isoladas da dieta de cabras leiteiras utilizando uma abordagem polifásica

Some species of filamentous fungi that infest agricultural commodities are able to produce mycotoxins, contaminating feed and animal products. The aim of this research was to identify the mycoflora present in the feed and forage for dairy goat and to isolate and characterize the Aspergillus flavus and A. parasiticus strains based on a morphological and molecular characterization and mycotoxigenic ability. The goat dairy diets were collected monthly from 11 goat milk farms, totaling 129 and 106 samples of concentrate and forage, respectively. For the isolation of the mycobiota the surface plating method was used. Aspergillus, Penicillium, and Fusarium were the main fungi producing mycotoxins isolated. The morphological and molecular characterization and mycotoxigenic ability were used for A. flavus and A. parasiticus identification. The Aspergillus spp. from feed 39% produced aflatoxins B1 and B2, 17% produced cyclopiazonic acid (CPA), 18% produced both toxins, and 42% had no toxigenic ability. Only 2.0% of the strains produced aflatoxins B1, B2, G1, and G2, but no CPA. The strains from forage were producers of aflatoxins B1 and B2 (37%), CPA (14%), 14% of both mycotoxins, whereas 49% have shown no toxigenic ability. The aflD and aflR genes were used by PCR and PCR-RFLP, respectively. The presence of toxigenic species in samples of feed for lactating goats indicates a potential risk of contamination of dairy products, if they are exposed to environmental conditions favorable to fungal growth and mycotoxin production.

Algumas espécies de fungos filamentosos que infestam os produtos agrícolas e ração são capazes de produzir micotoxinas. O objetivo deste trabalho foi identificar a micoflora presente nos concentrados e volumosos utilizados na dieta de cabras leiteiras e isolar as espécies Aspergillus flavus e A. parasiticus, com base em uma caracterização morfológica e molecular e capacidade micotoxigênica. Os alimentos foram coletados mensalmente em 11 fazendas produtoras de leite de cabra, totalizando 129 e 106 amostras de concentrado e volumoso, respectivamente. Para o isolamento da micobiota, foi utilizado o método de plaqueamento de superfície. Aspergillus, Penicillium e Fusarium foram os principais gêneros de fungos produtores de micotoxinas isolados das amostras. A caracterização morfológica e molecular e capacidade micotoxigênica foram utilizadas para identificação de A. flavus e A. parasiticus. Das cepas Aspergillus spp isoladas do concentrado, 39% produziram aflatoxinas B1 e B2, 17% produziram ácido ciclopiazônico (ACP), 18% produziram ambas as toxinas e 42% não tinham capacidade toxigênica. Apenas 2,0% das cepas produziram aflatoxinas B1, B2, G1 e G2. As cepas de Aspergillus spp. isoladas do volumoso foram produtores de aflatoxinas B1 e B2 (37%), ACP (14%), sendo que 14% produziram ambas toxinas e 49% não foram produtoras. Os genes aflD e aflR foram utilizados para a PCR e a PCR-RFLP, respectivamente. A presença de espécies toxigênicas em amostras de alimentos destinados a caprinos em lactação indica um risco potencial de contaminação dos produtos lácteos por aflatoxinas e ACP, caso estes sejam expostos a condições ambientais favoráveis ao crescimento de fungos e produção de micotoxinas.

Avaliação do extrato etanólico de casca de Punica granatum (romã) na diminuição da replicação viral do BoHV-1 Colorado em embriões murinos experimentalmente infectados / Evaluation of ethanol extract of Punica granatum (Pomegranate) peel decrease in viral replication of BoHV-1 in Colorado murine embryos experimentally infected

O objetivo do trabalho foi avaliar a diminuição da replicação viral (BoHV-1 Colorado) em embriões murinos após tratamento do extrato etanólico da casca de Punica granatum (EEPg). Camundongos fêmeas Swiss com idade entre 6 e 8 semanas foram superovuladas com 0,2 mL a 5 UI de hormônios (eCG e hCG), e acasaladas com machos da mesma idade. Após 18 horas, as fêmeas sofreram eutanásia em câmara de CO2 e, através de abertura no peritônio, os zigotos foram coletados e lavados com solução de pronase 0,5%.Os zigotos foram divididos em quatro grupos: G1 (controle), G2 (expostos aos vírus BoHV-1 Colorado a 108 TCID50/mL), G3 (expostos ao EEPg) e G4 (expostos aos vírus e ao EEPg). Os grupos foram mantidos a 37,5ºC em meio TCM199 (100µL) com 10% de soro fetal bovino em estufa a 5% de CO2 e 95% de umidade. Após 24 h, analisamos a taxa de clivagem (teste exato de Fisher; p<0,05), a morfologia (por microscopia óptica), a nested-PCR e a titulação dos embriões em cocultura com células MDBK após mais 72 h do tratamento (teste de Mann-Whitney; p<0,05) e microscopia eletrônica de transmissão (ME). Os embriões murinos tratados com EEPg apresentaram resultados satisfatórios: sem alterações morfológicas, taxa de clivagem semelhante ao controle e, apesar da detecção da presença do vírus pela nested-PCR e ME, houve diminuição do título viral após tratamentos com esse extrato, o que sugere interferência desse tratamento no ciclo viral do BoHV-1 Colorado sem alterar o desenvolvimento dos embriões.(AU)

The aim of this study was to evaluate the reduction of viral replication (Colorado BoHV-1) in murine embryos after the treatment of ethanol extract of Punica granatum peel (PgEE). Swiss female mice aged 6 to 8 weeks were superovulated with 0.2 mL of the 5 UI hormones (eCG and hCG) and mated with males of the same age. After 18 hours, the females were euthanized in a CO2 chamber, and through the opening in the peritoneum, zygotes were collected and washed with 0.5% pronase solution. The zygotes were divided into four groups: G1 (control), G2 (exposed to the virus Colorado BoHV -1 to 108 TCID50/mL), G3 (exposed to PgEE) and G4 (exposed to the virus and to PgEE). The groups were maintained at 37.5ºC in TCM199 (100 mL) with 10% fetal bovine serum in an incubator at 5% CO2 and 95% humidity. After 24 h, we analyzed the cleavage rate (Fisher's exact test; p<0.05), the morphology (by light microscopy), the nested-PCR and the titration of embryos in co-culture with MDBK cells after over 72 h of treatment (Mann-Whitney test; p<0.05) and transmission electron microscopy (TEM). The murine embryos treated with PgEE showed satisfactory results: no morphological changes, cleavage rate similar to controls, despite the detection of the presence of virus by nested PCR and TEM, there was a decrease of the viral titer after the treatment with this extract, which suggests interference of this treatment in the viral cycle BoHV-1 Colorado without altering the embryo development.(AU)

Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus.

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 µL for oregano and 50, 30, 15, and 10 µL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3 × 10(5) spores/mL in 60 g of grains (corn and soybeans) after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

Production of aflatoxin and cyclopiazonic acid by Aspergillus flavus strains isolate from peanuts / Produção de aflatoxinas e ácido ciclopiazônico por cepas de Aspergillus flavus isoladas de amendoim

Aspergillus flavus is a filamentous fungus that can produce aflatoxins and cyclopiazonic acid, and the presence of these mycotoxins in food and feed can lead to a toxic effect on humans and animals. Strains of A. flavus producing aflatoxin and cyclopiazonic acid are often isolated from peanuts, indicating the the co-occcurrence of these toxins in the natural substrate. In this study, we isolated 47 strains of A. flavus on peanut kernels and hulls during different stages of fruit ripening and its storage. Of the isolated strains, we assessed the potential for aflatoxin and cyclopiazonic acid production, in which 91.5% could produce aflatoxins and 70% produced cyclopiazonic acid; 63.8% produced both toxins and 2.1% produced no toxin. The presence of toxigenic A. flavus strains in peanut samples indicate a potential risk of contamination of these products, if they are exposed to environmental conditions that are favorable to fungal growth and mycotoxin production.

Aspergillus flavus é um fungo filamentoso que pode produzir aflatoxinas e لcido ciclopiazônico, sendo que a presença dessas micotoxinas em alimentos e raçُes pode levar a um efeito tَxico no homem e em animais. Cepas de A. flavus produtoras de aflatoxinas e لcido ciclopiazônico sمo frequentemente isoladas do amendoim, indicando a natural co-ocorrência dessas toxinas neste substrato. Neste estudo, foram isoladas 47 cepas de Aspergillus flavus em grمos e cascas de amendoim durante diferentes fases de maturaçمo do fruto e também durante seu armazenamento. Das cepas isoladas, foram avaliados os potenciais para produçمo de aflatoxinas e لcido ciclopiazônico, em que 91,5% foram produtoras de aflatoxinas e 70% produziram لcido ciclopiazônico, sendo que 63,8% produziram ambas as toxinas e 2,1% nمo produziu nenhuma. A presença de cepas toxigênicas de A. flavus nas amostras de amendoim analisadas indica um risco potencial da contaminaçمo deste produto, caso seja exposto a condiçُes ambientais favorلveis ao crescimento do fungo e produçمo de micotoxinas.

Mycotoxins detection by chromatography.

Mycotoxins are metabolites and toxic substances produced by certain filamentous fungi that frequently contaminate food and agriculture commodities and it may cause disease in animals or humans. The toxigenic fungi are responsible for mycotoxin production in food that belongs to mainly three genera: Aspergillus, Penicillium and Fusarium. The contamination of food by mycotoxins is difficult to control in addition, causing economic impacts on public health, so their identification and quantifications are very necessary. Various analytical methods are developed for the detection and quantification of mycotoxins in order to control the residual contents of these toxins. Among them there is a widely used chromatography. This paper reports some chromatographic methods for the detection and quantification of mycotoxins described in patents and scientific articles.

Evaluation of antifungal activity of Pittosporum undulatum L. essential oil against Aspergillus flavus and aflatoxin production / Avaliação da atividade antifúngica do óleo essencial de Pittosporum undulatum L. em Aspergillus flavus e produção de aflatoxina

The presence of mycotoxins as a result of fungal attack can occur before, after and during the harvest and storage operations on agricultural crops and food commodities. Considering the inhibitory property of essential plant oils on the mycelial development of fungi and the importance of Aspergillus flavus, the main producer of aflatoxins, this research was designed to evaluate the toxicity of essential oil from Pittosporum undulatum against A. flavus. The essential oils were obtained from P. undulatum leaves, collected in different months and analyzed by GC/MS. The oils were rich in hydrocarbon, monoterpenes and sesquiterpenes and it was observed a significant variation on the chemical composition of the essential oil of leaves at different months. Besides, the essential oils were tested against fungal growth and the results showed different spectrum of inhibition on A. flavus. However, the essential oils inhibited the aflatoxin B1 production.

A presença de micotoxinas como resultado do ataque fúngico pode ocorrer antes, após e durante a colheita e também no armazenamento de grãos e alimentos. Considerando as propriedades inibitórias dos óleos essenciais de plantas no desenvolvimento do micélio dos fungos e a importâncias do Aspergillus flavus, principal produtor de aflatoxinas, relatou-se neste trabalho, a atividade tóxica do óleo essencial do Pittosporum undulatum em cultura de A. flavus. Os óleos essenciais de P. undulatum foram obtidos a partir de folhas coletadas em diferentes meses e analisado por CG/EM. Os óleos se mostraram ricos em hidrocarbonetos, monoterpenos e sesquiterpenos e foi observada uma significante variação na composição química destes óleos nos diferentes meses de coleta. Os óleos essenciais mostraram diferentes espectros de inibição do crescimento de A. flavus, porém todos foram capazes de inibir a produção de aflatoxina B1.

Fungi, mycotoxins and phytoalexin in peanut varieties, during plant growth in the field.

The aim of the present study was to analyze the mycobiota, occurrence of mycotoxins (aflatoxins and cyclopiazonic acid), and production of phytoalexin (trans-resveratrol) in two peanut varieties (Runner IAC 886 and Caiapó) during plant growth in the field. Climatic factors (rainfall, relative humidity and temperature) and water activity were also evaluated. The results showed a predominance of Fusarium spp. in kernels and pods, followed by Penicillium spp. and Aspergillus flavus. Aflatoxins were detected in 20% and 10% of samples of the IAC 886 and Caiapó varieties, respectively. Analysis showed that 65% of kernel samples of the IAC 886 variety and 25% of the Caiapó variety were contaminated with cyclopiazonic acid. trans-Resveratrol was detected in 6.7% of kernel samples of the IAC 886 variety and in 20% of the Caiapó variety. However, trans-resveratrol was found in 73.3% of leaf samples in the two varieties studied.

Ageratum conyzoides essential oil as aflatoxin suppressor of Aspergillus flavus.

Aflatoxin B(1) (AFB(1)) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oil of Ageratum conyzoides, on the mycelial growth and aflatoxin B(1) production by Aspergillus flavus were studied. Cultures were incubated in yeast extract-sucrose (YES) broth for days at 25 degrees C at the following different concentrations of the essential oil (from 0.0 to 30mug/mL). The essential oil inhibited fungal growth to different extents depending on the concentration, and completely inhibited aflatoxin production at concentrations above 0.10microg/mL. The analysis of the oil by GC/MS showed that its main components are precocene II (46.35%), precocene I (42.78%), cumarine (5.01%) and Trans-caryophyllene (3.02%). Comparison by transmission electron microscopy of the fungal cells, control and those incubated with different concentrations of essential oil, showed ultra-structural changes which were concentration dependent of the essential oil of A. conyzoides. Such ultra-structural changes were more evident in the endomembrane system, affecting mainly the mitochondria. Degradation was also observed in both surrounding fibrils. The ability to inhibit aflatoxin production as a new biological activity of A.conyzoides L. indicates that it may be considered as a useful tool for a better understanding of the complex pathway of aflatoxin biosynthesis.

Chemical and biological approaches for mycotoxin control: a review.

Mycotoxins are metabolites and toxic substances produced by certain filamentous fungi that frequently contaminate food and agriculture commodities, which cause disease in animals or man. The toxigenic fungi belong to mainly three genera: Aspergillus, Penicillium and Fusarium. Examples of mycotoxins of greatest public health and agroeconomic significance include aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, patulin and ergot alkaloids. Commodities susceptible to direct contamination with mycotoxins include nuts, oilseeds and grains. Chemical and biological treatments have been attempted to minimize the risk of mycotoxins contamination or eliminate the fungi of food and feeds. One way to prevent or interfere with fungal growth and mycotoxin production is by use of synthetic or natural agents. Bacteria have been studied to control the mycotoxins production and fungal growth in food. Plant genotypes resistant to infection by toxigenic fungi have been also studied. This review will approach same patented methods applied to degrade, prevent and control of mycotoxins in food and feeds.

Avaliação da micoflora e ocorrência de micotoxinas em cascas de amendoim em diferentes estágios de maturação da vagem / Evaluation of mycoflora and occurrence of mycotoxins in peanut hulls at different pod maturation stages

As cascas de amendoim (Arachis hypogaea L.) são de grande importância para confecção de cama de frangos, de gado de leite e como fonte de fibras para ruminantes, portanto a elucidação dos mecanismos de contaminação por fungos toxigênicos e por micotoxinas em amendoim é imprescindível, especialmente para que medidas preventivas possam ser tomadas. Realizou-se, este trabalho, em Junqueirópolis, Estado de São Paulo, Brasil. Os principais fungos isolados nas cascas de amendoim foram Fusarium ssp. (78,75 por cento), Rhizopus ssp. (14,1 por cento) e A. flavus (11,75 por cento). No solo foram isolados Penicillium spp., Fusarium spp. e Aspergillus flavus, entre outros. Aflatoxinas foram detectadas em amostras de cascas de amendoim a partir do estágio de granação em concentrações que variaram de 5,42 μg/kg a 218,52 μg/kg. Ácido ciclopiazônico e fumonisinas B1 e B2 não foram detectadas. A presença de A. flavus e aflatoxinas nas amostras, revela a importância de um controle das cascas de amendoim antes de sua utilização. Boas práticas agrícolas são indicadas para região, uma vez que a contaminação das vagens ocorreu antes da colheita.

Peanut (Arachis hypogaea L.) hulls are very important because they are used as litter to poultry and dairy cattle and as fiber source to cattle. The elucidation of the peanuts contamination mechanisms by toxigenic fungi and their mycotoxins is vital, specially for prevention measurements. The peanuts total mycoflora and mycotoxin contamination were analyzed in plants sampled in Junqueirópolis, in São Paulo State (Brazil) at different stages of the pod maturity. The prevalent mycoflora in peanut hulls were Fusarium spp., Rhizopus spp. and Aspergillus flavus. In soil under the peanut crop, the genus Penicillium spp., Fusarium spp. and A. flavus were detected. Aflatoxins were detected in peanut hull samples since filling pod stage in concentrations from 5.42 μg/kg to 218.52 μg/kg. Cyclopiazonic acid and fumonisins were not detected. The A. flavus presence and the detection of aflatoxins indicate the importance of quality control of peanut hulls before their utilization, and the adoption of agricultural practices showed to avoid the contamination since the peanut pods contamination happened before the harvest.

Study of the antitumor potential of Bidens pilosa (Asteraceae) used in Brazilian folk medicine.

AIM OF THE STUDY: Bidens pilosa (L.) (Asteraceae) is a medicinal plant traditionally used in Brazil for treating conditions that can be related to cancer. Therefore the present study was carried out to evaluate the antitumor activity of extracts obtained from the aerial parts of this plant species. MATERIALS AND METHODS: The crude hydroalcoholic extract (HAE) (water:alcohol, 6:4) and solvent fractions (chloroform=CHCl3,ethyl acetate=EtOAc, methanol=MeOH) were assessed for cytotoxicity assay by the brine shrimp and hemolytic, MTT and NRU assays. The antiproliferative potential of the crude extract and fractions was investigated in vivo using the Ehrlich ascites carcinoma (EAC) in isogenic Balb/c mice that were administered intraperitoneally 150 and 300 mg/kg body weight per day for nine days beginning 24 h after tumor inoculation. RESULTS: In in vitro cytotoxicity using Ehrlich ascites carcinoma cell line assay CHCl3 extract proved to be more toxic than the crude HAE with an IC(50) of 97+/-7.2 and 83+/-5.2 microg/mL to NRU and MTT, respectively. Histomorphological evaluations indicated that the treatment with CHCl3 and HAE extracts significantly reduced (P<0.05) body weight, abdominal circumference, tumor volume, packed cell volume and viable cell count, when compared to EAC control group. Furthermore, nonviable tumor cell count increased significantly (P<0.01) only under treatment with CHCl3 or HAE, and this was accompanied by a marked percentage increase in life span (54.2 and 41.7%, respectively). Biochemical assays revealed that CHCl3 and HAE extracts were also able to decrease serum LDH activity (39.5 and 30.6%) and GSH concentration (94.6 and 50.7%) in ascitic fluid, respectively. CONCLUSION: The chloroform fraction showed the best and methanolic the worst antitumor activity.

Mycobiota and mycotoxins in Brazilian peanut kernels from sowing to harvest.

The total mycobiota and the mycotoxin contamination of peanuts were analyzed in plants collected at different stages of the pod maturity sampled in Junqueirópolis, at São Paulo State (Brazil). The prevalent peanut mycobiota were Fusarium spp. and Aspergillus flavus, present in 26% and 17% respectively of the samples analyzed. In soil, the genus Penicillium and Fusarium were most frequently detected, and A. flavus was detected in 8% of the samples. The screening of mycotoxins indicated that aflatoxins and cyclopiazonic acid were present the highest incidence, being detected in 32% of the samples, in concentrations, respectively, from 4.20 microg/kg to 198.84 microg/kg and from 260 microg/kg to 600 microg/kg. Fumonisins were not detected by HPLC. All data were correlated with the occurrence of wind-dispersed fungi and the environmental and soil conditions. Results indicate that good management of the agricultural environment may offer a way to reduce mycotoxins and the toxigenic fungal contamination in peanuts preharvest because the pods are exposed to different environmental conditions during their formation until harvest, and the optimal conditions for mycotoxin production and fungal growth are frequently found in the crop fields.

Free-radical scavenging by Ouratea parviflora in experimentally-induced liver injuries.

The antioxidant potential of crude extracts and fractions from leaves of Ouratea parviflora, a Brazilian medicinal plant used for the treatment of inflammatory diseases, was investigated in vitro through the scavenging of radicals 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), hydroxyl radical (HO*), superoxide anion (O2*-), and lipid peroxidation in rat liver homogenate. The crude extract (CEOP) and hydro-alcoholic fraction (OP4) showed strong inhibitory activity toward lipid peroxidation induced by tert-butyl peroxide (IC50 = 2.3 +/- 0.2 and 1.9 +/- 0.1 microg/ml, respectively). The same products exhibited a strong concentration-dependent inhibition of deoxyribose oxidation (14.9 +/- 0.2 and 0.2 +/- 0.1 microg/ml, respectively), and also showed a considerable antioxidant activity against O2*- (87.3 +/- 0.1 and 73.1 +/- 0.4 microg/ml, respectively) and DPPH radicals (55.4 +/- 0.3 and 38.3 +/- 0.4 microg/ml, respectively). The protective effects of CEOP and OP4 were also studied in mouse liver. CCl4 significantly increased (by 90%) levels of lipid hydroperoxides, carbonyl protein content (64%), DNA damage index (133%), aspartate aminotransferase (261%), alanine aminotransferase (212%), catalase activity (23%), and also caused a decrease of 60% in GSH content. The results showed that CEOP and OP4 exerted cytoprotective effects against oxidative injury caused by CCl4 in rat liver, probably related to the antioxidant activity showed by the in vitro free radical scavenging property.

Inhibitory activity of compounds isolated from Polymnia sonchifolia on aflatoxin production by Aspergillus flavus

Polymnia sonchifolia, conhecida como "Yacon", e originária da cordilheira dos Andes, sendo muito conhecida devido ao uso de seu tubérculo no controle da Diabetes melitus. Suas folhas podem conter compostos com atividade antifúngica e pesticida, pois não é necessário o uso destes produtos no seu cultivo. Neste trabalho descrevemos a identificação da estrutura química de dois flavonóides isolados das folhas de Polymnia sonchifolia: 3', 5, 7 trihydroxy-3, 4'-dimethoxyflavone (composto 1) e 3',4',5-trihidroxi-7-metoxiflavanona (composto 2) e de duas lactonas sesquiterpenicas: enidrina (composto 3) e uma mistura de enidrina e uvedalina (composto 4), bem como seus efeitos na produção de aflatoxinas por Aspergillus flavus. A identificação dos compostos foi realizada por RMN 13C e 1H. Todos os compostos foram testados em diversas concentrações em cultura de Aspergillus flavus para avaliar o crescimento e a produção de aflatoxina. O composto 1 na concentração de 15 mg/mL inibiu 25 por cento da produção de aflatoxina B1 (p<0,01). O composto 4 inibiu o crescimento do fungo e a produção da aflatoxina B1 em 34 por cento e 76 por cento, respectivamente. Os resultados mostraram a possibilidade do uso de Polymnia sonchifolia no controle alternativo da producao de aflatoxina B1 pelo fungo Aspergillus flavus.

Intoxicaçäo de vacas leiteiras por farelo de algodäo naturalmente contaminado com aflatoxinas / Dairy cows poisoned with cottonseed meal naturally contaminated with aflatoxins

Aflatoxina M1 é um dos metabólitos tóxico da aflatoxina B1, excretada pelo leite de animais que ingerem alimentos contaminados. O presente trabalho descreve o caso de uma fazenda produtora de leite na regiäo de Itú, Säo Paulo, onde os animais foram alimentados com farelo de algodäo naturalmente contaminado com as aflatoxinas. As aflatoxinas B1, B2, G1 e G2 foram identificadas por CCD e quantificadas por fotodensitometria nas concentraçöes de 43,5; 15,2; 9,1 e 8,6ng.g-1 respectivamente. O leite destes animais foi analisado por cromatografia líquida de alta eficiência (CLAE), e a aflatoxina M1 foi identificada e quantificada (0,64ng.mL-1). As concentraçöes encontradas para as aflatoxinas no farelo de algodäo e no leite estäo acima dos valores permitidos pela legislaçäo brasileira, representando um risco à saúde pública.

Activity of the aqueous extract from Polymnia sonchifolia leaves on growth and production of aflatoxin B1 by Aspergillus flavus

Neste trabalho verificou-se a atividade do extrato aquoso de folhas de Polymnia sonchifolia no crescimento e na produção de aflatoxinas B1 por Aspergillus flavus. Suspensões de esporos de A. flavus foram inoculadas em 50 mL de meio de YES com diferentes concentrações do extrato aquoso. A aflatoxina B1 foi extraída e analisada por cromatografia de camada delgada e quantificada por fotodensitometria. Todas as concentrações testadas inibiram a produção de aflatoxina B1. O extrato aquoso apresentou citotoxicidade em células Vero somente em concentrações acima de 500 µg/mL.