Lutein and Zeaxanthin Content in 21 Plant Species from a Very Humid Premontane Forest in Colombia Palatable for Free-Range Laying Hens.

Xanthophylls, such as lutein and zeaxanthin, have several functions in both plants and humans, including detoxification of oxidants (reactive oxygen species (ROS) and other radicals), maintenance of the structural and functional integrity of biological membranes, and photoprotection from intense light damage. The objective of the present study was to investigate the lutein and zeaxanthin content of 21 species of plants from a very humid premontane forest in Colombia during both dry and rainy seasons. The plants were selected based on being voluntarily eaten by laying hens under free-range conditions. Lutein and zeaxanthin were identified and quantified by high-performance liquid chromatography (HPLC). The results showed that all plants tested contained lutein, at levels ranging from 65.7 to 350 µg/g. Zeaxanthin levels were much lower (2.2 to 26.2 µg/lg) and were detected in only 5 of the 21 plants analyzed. Given that the lutein content of the plants tested in the present study was found to be comparable to that reported in marigold flowers (4-800 µg/g), it is possible that these plants can be used as a source of lutein in free-range laying hen production systems.

Anti-SpCas9 IgY Polyclonal Antibodies Production for CRISPR Research Use.

The CRISPR/Cas adaptative immune system has been harnessed as an RNA-guided, programmable genome editing tool, allowing for diverse biotechnological applications. The implementation of the system relies on the ability to detect the Cas9 protein in biological samples. This task is facilitated by employing antibodies, which exhibit several advantageous features and applications in the context of tropical neglected diseases. This study reports a one-month immunization scheme with the Cas9 protein fromStreptococcus pyogenes to produce IgY polyclonal antibodies (anti-SpCas9), which can be rapidly isolated by combining yolk de-lipidation with protein salting out using pectin and ammonium sulfate, respectively. Immunodetection assays indicate that the antibodies are highly sensitive, specific, and useful for detecting the SpCas9 protein in promastigotes ofLeishmania braziliensisexpressing exogenous SpCas9. Thus, the simple method for producing anti-SpCas9 IgY antibodies will accelerate CRISPR/Cas-based studies in Leishmania spp. This approach serves as a valuable research tool in this parasite model and holds the potential for wide application in various other biological samples, promoting the implementation of the system. In fact, a bioinformatics approach based on the identification of antigenic determinants in the SpCas9 protein suggests the possibility of using the anti-SpCas9 IgY antibodies in applications such as Prime and Base editing.

Colombian vs. American corn: Quality, chemical composition, mycotoxin content and metabolizable energy

Background: Corn is, quantitatively, one of the most important world crops (ranking second only after wheat) and a key ingredient in animal feeds. Objective: to assess and compare corn quality, mycotoxin content, chemical composition and apparent metabolizable energy (AME) of domestic and imported corn. Methods: Grain quality (USDA grading system) was determined in 30 samples of domestic and 21 samples of imported corn. From each origin, 15 samples were subjected to proximal analysis and 10 were used to determine fatty acid composition. Mycotoxin analysis was conducted on 30 samples of domestic and 23 of imported corn. Results: six of the 30 domestic samples corresponded to US1 grade (highest quality) vs. none of the imported. In the "sample grade" category (lowest quality), 10 and 6 samples corresponded to imported and domestic corn, respectively. Soybeans were found as contaminant in 15 of the 21 imported corn samples. Aspergillus spp. mycotoxins such as ochratoxin A were not detected, and aflatoxins were found in only a few samples at very low levels. Fusariotoxins such as deoxynivalenol and zearalenone were found in 61 and 43% of imported samples, respectively, but in none of the domestic samples. Domestic corn had lower carbohydrate content compared with imported corn (85.4 vs. 86.7%), but higher crude fat (3.8 vs. 3.1%). The AME values for domestic and imported corn were 3,697 and 3,378 kcal/kg, respectively. The fatty acid profiles from both corn types were similar. Conclusion: This study found significant differences between locally-grown and imported corn, particularly in terms of crude fat, AME content, fusariotoxins, and contaminant seeds (soybeans). These findings suggest that locally-grown corn might have nutritional and toxicological advantages over corn imported from the United States.

Antecedentes: El maíz es, cuantitativamente, uno de los cultivos más importantes a nivel mundial (ocupa el segundo lugar después del trigo) y uno de los principales ingredientes en dietas para animales. Objetivo: Evaluar y comparar la calidad del maíz, su contenido de micotoxinas, composición química, y energía metabolizable aparente (AME) del maíz nacional e importado. Métodos: La calidad del grano (sistema de clasificación de la USDA) se determinó en 30 muestras de maíz producido en Colombia y 21 de maíz importado. De cada origen, 15 muestras se sometieron a análisis proximal y 10 se analizaron para determinar el perfil de ácidos grasos. El contenido de micotoxinas se determinó en 30 muestras de maíz nacional y 23 de maíz importado. Resultados: Seis de las treinta muestras nacionales analizadas para calidad de grano correspondieron a grado US1 (la mejor calidad) frente a ninguna de las importadas. En categoría "grado muestra" (la menor calidad) se encontraron 10 y 6 de las muestras de maíz importado y nacional, respectivamente; 15 de las 21 muestras de maíz importado presentaron contaminación con semillas de fríjol soya. No se encontraron micotoxinas de hongos Aspergillus spp. (ocratoxina A), y niveles muy bajos de aflatoxinas en unas pocas muestras. Fusariotoxinas tales como deoxinivalenol y zearalenona se detectaron en el 61 y 43% de las muestras de maíz importado, respectivamente, pero en ninguna muestra de maíz nacional. El maíz nacional presentó menor contenido de carbohidratos (85,4 vs. 86,7%), pero mayor contenido de grasa cruda (3,8 vs. 3,1%) en comparación con el importado, respectivamente. Los valores de AME fueron de 3.697 y 3.378 kcal/kg para el maíz nacional e importado, respectivamente. El perfil de ácidos grasos de ambas procedencias fue similar. Conclusiones: Este estudio encontró diferencias significativas entre el maíz de producción nacional y el importado, en especial en su contenido de grasa cruda y AME, fusariotoxinas, y semillas contaminates (soya). Estos hallazgos sugieren que el maíz de producción nacional puede presentar ventajas de tipo nutricional y toxicológico frente al maíz importado de los Estados Unidos de América.

Antecedentes: O milho é quantitativamente uma das culturas mais importantes em nível mundial (ocupando o segundo lugar depois do trigo), sendo um dos principais ingredientes em dietas para animais. Objetivo: Avaliar e comparar a qualidade do milho, o teor de micotoxinas, a composição química e a energia metabolizável aparente (EMA) do milho nacional e importado. Métodos: A qualidade do grão (sistema de classificação do USDA) foi determinada em 30 amostras de milho produzido na Colômbia e 21 amostras de milho importado. Quinze amostras de cada tipo de milho foram submetidas a análise proximal e dez amostras de cada milho foram analisadas para determinar o perfil de ácidos graxos. O conteúdo de micotoxinas foi determinado em 30 amostras de milho da Colômbia e em 23 amostras de milho importado. Resultados: Seis das trinta amostras colombianas analisadas para qualidade de grão corresponderam a grau US1 (melhor qualidade) frente a nenhuma das amostras importadas. Na categoria "grau amostra" (menor qualidade) foram encontradas 10 e 6 amostras de milhos importados e colombianos, respectivamente; Quinze das 21 amostras de milho importado apresentaram contaminação com sementes de feijão soja. Não foram encontradas micotoxinas de fungos Aspergillus spp. (ocratoxina A) ou apenas níveis muito baixos em poucas amostras (aflatoxinas). As fusariotoxinas, deoxinivalenol e zearalenona foram detectadas em 61 e 43% das amostras de milho importado, respectivamente, mas não foram detectadas em nenhuma amostra do milho colombiano. O milho colombiano apresentou menor conteúdo de carboidratos (85,4 vs. 86,7%) porém maior conteúdo de gordura crua (3,8 vs. 3,1%). Os valores de AME foram 3.697 e 3.378 kcal/kg para as amostras de milho colombiano e importado, respectivamente. O perfil de ácidos graxos de ambos tipos de milho foi similar. Conclusões: Os resultados do presente estudo mostram diferenças significativas entre o milho de origem colombiana e o milho importado dos Estados Unidos, em especial no conteúdo de gordura crua e AME, fusariotoxinas e sementes contaminantes (soja). Estes achados sugerem que o milho de produção colombiana pode apresentar vantagens de tipo nutricional e toxicológica frente ao milho importado dos Estados Unidos.

Protective effect of glutathione S-transferase enzyme activity against aflatoxin B1 in poultry species: relationship between glutathione S-transferase enzyme kinetic parameters, and resistance to aflatoxin B1.

Comparative studies designed to investigate the role of glutathione S-transferase (GST) activity on the enzyme catalyzed trapping of aflatoxin B1-8,9-epoxide (AFBO) with glutathione, and the relationship with aflatoxin B1 (AFB1) resistance have not been conducted in poultry. Hepatic cytosolic fractions of chickens, quail, turkeys and ducks were used to measure in vitro the enzymatic parameters maximal velocity (Vmax), Michaelis-Menten constant (Km) and intrinsic clearance (CLint) for GST activity. AFB1 used ranged from 2.0 to 157.5 µM and the AFB1-GSH produced was identified and quantitated by HPLC. Significant differences were found in GST Vmax values, being the highest in chickens, followed by quail, ducks and turkeys. The Km values were also significantly different, with chickens < ducks < turkeys < quail. Chickens had the higher CLint value in contrast to ducks. Differences by sex showed that duck females had a higher CLint value than the turkey and quail, whereas duck males had a CLint close to that of turkey. The ratio "AFBO production /AFB1-GSH production" follows the order duck>turkey>quail>chicken, in agreement with the known poultry sensitivity. The extremely high "AFB1 epoxidation activity/ GST activity" ratio observed in ducks might be the explanation for the development of hepatocellular carcinoma in this species.

Dealing with aflatoxin B1 dihydrodiol acute effects: Impact of aflatoxin B1-aldehyde reductase enzyme activity in poultry species tolerant to AFB1 toxic effects.

Aflatoxin B1 aldehyde reductase (AFAR) enzyme activity has been associated to a higher resistance to the aflatoxin B1 (AFB1) toxicity in ethoxyquin-fed rats. However, no studies about AFAR activity and its relationship with tolerance to AFB1 have been conducted in poultry. To determine the role of AFAR in poultry tolerance, the hepatic in vitro enzymatic activity of AFAR was investigated in liver cytosol from four commercial poultry species (chicken, quail, turkey and duck). Specifically, the kinetic parameters Vmax, Km and intrinsic clearance (CLint) were determined for AFB1 dialdehyde reductase (AFB1-monoalcohol production) and AFB1 monoalcohol reductase (AFB1-dialcohol production). In all cases, AFB1 monoalcohol reductase activity saturated at the highest aflatoxin B1 dialdehyde concentration tested (66.4 µM), whereas AFB1 dialdehyde reductase did not. Both activities were highly and significantly correlated and therefore are most likely catalyzed by the same AFAR enzyme. However, it appears that production of the AFB1 monoalcohol is favored over the AFB1 dialcohol. The production of alcohols from aflatoxin dialdehyde showed the highest enzymatic efficiency (highest CLint value) in chickens, a species resistant to AFB1; however, it was also high in the turkey, a species with intermediate sensitivity; further, CLint values were lowest in another tolerant species (quail) and in the most sensitive poultry species (the duck). These results suggest that AFAR activity is related to resistance to the acute toxic effects of AFB1 only in chickens and ducks. Genetic selection of ducks for high AFAR activity could be a means to control aflatoxin sensitivity in this poultry species.

Effect of full-fat sunflower or flaxseed seeds dietary inclusion on performance, egg yolk fatty acid profile and egg quality in laying hens.

A study was conducted to evaluate the effect of the dietary inclusion of full-fat flaxseed or full-fat sunflower seeds on performance parameters, egg quality parameters and egg yolk fatty acid profile in laying hens. A total of 150 Babcock Brown hens at 27 weeks of age were distributed in 3 experimental treatments, as follows: T1, control; T2, diet containing 13.5% full-fat whole flaxseed seeds; and T3, diet containing 13.5% full-fat ground sunflower seeds. Feed and water were provided ad libitum and the experiment lasted for 8 weeks. No significant differences were found on egg quality parameters, but total egg production and rate of lay were significantly (P < 0.05) lower in the group receiving sunflower seeds compared with the control, and significant differences (P < 0.05) in egg yolk saturated, monounsaturated, polyunsaturated, omega-6 (n-6) and omega-3 (n-3) fatty acids were observed, as well as in the n-6:n-3 ratio. The results show that the dietary inclusion of 13.5% flaxseed full-fat seeds significantly increases the n-3 polyunsaturated fatty acid (PUFA) content in the eggs and lowers the n-6:n-3 ratio without affecting performance parameters. Inclusion of full-fat sunflower seeds increases the n-6 PUFA content but affects total egg production and rate of lay. Further studies are needed to determine the level of inclusion of full-fat sunflower seeds that does not affect performance.

In vitro hepatic aflatoxicol production is related to a higher resistance to aflatoxin B1 in poultry.

A study was conducted to determine the cytosolic in vitro hepatic enzymatic kinetic parameters Vmax, KM, and intrinsic clearance (CLint) for aflatoxin B1 (AFB1) reductase [aflatoxicol (AFL) production] and AFL dehydrogenase (AFB1 production) in four commercial poultry species (chicken, quail, turkey and duck). Large differences were found in AFB1 reductase activity, being the chicken the most efficient producer of AFL (highest CLint value). Oxidation of AFL to AFB1 showed only slight differences among the different poultry species. On average all species produced AFB1 from AFL at a similar rate, except for the turkey which produced AFB1 from AFL at a significantly lower rate than chickens and quail, but not ducks. Although the turkey and duck showed differences in AFL oxidation Vmax and KM parameters, their CLint values did not differ significantly. The ratio AFB1 reductase/AFL dehydrogenase enzyme activity was inversely related to the known in vivo sensitivity to AFB1 being highest for the chicken, lowest for the duck and intermediate for turkeys and quail. Since there is no evidence that AFL is a toxic metabolite of AFB1, these results suggest that AFL production is a detoxication reaction in poultry. Conversion of AFB1 to AFL prevents the formation of the AFB1-8,9-exo-epoxide which, upon conversion to AFB1-dihydrodiol, is considered to be the metabolite responsible for the acute toxic effects of AFB1.

An unusually high production of hepatic aflatoxin B1-dihydrodiol, the possible explanation for the high susceptibility of ducks to aflatoxin B1.

A study was conducted to determine the enzymatic kinetic parameters Vmax, KM, and intrinsic clearance (CLint) for the hepatic in vitro production of aflatoxin B1-dihydrodiol (AFB1-dhd) from aflatoxin B1 (AFB1) in four commercial poultry species, ranging in sensitivity to AFB1 from highest (ducks) to lowest (chickens). Significant but small differences were seen for Vmax, while large significant differences were observed for KM. However, the largest inter-species differences were observed for the CLint parameter, with ducks being extraordinarily efficient in converting AFB1 into AFB1-dhd. Since AFB1-dhd is considered the metabolite responsible for the acute toxic effects of AFB1, the high hepatic production of AFB1-dhd from AFB1 in ducks is the possible biochemical explanation for the extraordinary high sensitivity of this poultry species to the adverse effects of AFB1.

GlSir2.1 of Giardia lamblia is a NAD+-dependent cytoplasmic deacetylase.

The sirtuins are a group of well-conserved proteins widely distributed across all domains of life. These proteins are clustered in the class III of histone deacetylases and are distinctly characterized by their dependence upon NAD+ to carry out the deacetylation of lysine residues in histone proteins (H3 and H4) and non-histones such as the transcription factor p53. The requirement of NAD+ for sirtuin activity makes this group of proteins metabolic sensors, which are favored during caloric stress. Currently, it is known that these proteins are involved in numerous cellular processes that are fundamental for the proper functioning of cells, including control of the cell cycle and cellular survival. In spite of the importance of sirtuins in cell functions, the role that these proteins play in protozoan parasites is not completely understood. In this study, bioinformatic modeling and experimental characterization of the candidate G1Sir2.1 present in the genome of Giardia lamblia were carried out. Consequently, cloning, expression, purification, and in vitro evaluation of the recombinant GlSir2.1 protein's capacity for deacetylation were performed. This allowed for the identification of the NAD+-dependent deacetylase activity of the identified candidate. Production of anti-rHis-GlSir2.1 polyclonal antibodies enabled the observation of a cytoplasmic localization for the endogenous protein in trophozoites, which exhibited a perinuclear aggregation and co-localization with acetylated cytoskeleton structures such as the flagella and median body. Currently, GlSir2.1 is the second sirtuin family member identified in G. lambia, with a demonstrated cytoplasmic localization in the parasite.

Localization and phosphorylation of Plasmodium falciparum nicotinamide/nicotinate mononucleotide adenylyltransferase (PfNMNAT) in intraerythrocytic stages.

BACKGROUND: Nicotinamide adenine dinucleotide (NAD+) is an essential molecule in the energy metabolism of living beings, and it has various cellular functions. The main enzyme in the biosynthesis of this nucleotide is nicotinamide/nicotinate mononucleotide adenylyltransferase (NMNAT, EC 2.7.7.1/18) because it is the convergence point for all known biosynthetic pathways. NMNATs have divergences in both the number of isoforms detected and their distribution, depending on the organism. METHODS: In the laboratory of basic research in biochemistry (LIBBIQ: acronym in Spanish) the NMNATs of protozoan parasites (Leishmania braziliensis, Plasmodium falciparum, Trypanosoma cruzi, and Giardia duodenalis) have been studied, analysing their catalytic properties through the use of proteins. Recombinants and their cellular distribution essentially. In 2014, O'Hara et al. determined the cytoplasmic localization of NMNAT of P. falciparum, using a transgene coupled to GFP, however, the addition of labels to the study protein can modify several of its characteristics, including its sub-cellular localization. RESULTS: This study confirms the cytoplasmic localization of this protein in the parasite through recognition of the endogenous protein in the different stages of the asexual life cycle. Additionally, the study found that PfNMNAT could be a phosphorylation target at serine, tyrosine and threonine residues, and it shows variations during the asexual life cycle. CONCLUSIONS: These experiments confirmed that the parasite is situated in the cytoplasm, fulfilling the required functions of NAD+ in this compartment, the PfNMNAT is regulated in post-transcription processes, and can be regulated by phosphorylation in its residues.

Effects on health, performance, and tissue residues of the ionophore antibiotic salinomycin in finishing broilers (21 to 38 d).

A study was conducted to evaluate the effects of feeding salinomycin at the recommended prophylactic level, and at 2 and 3 times this level, to finishing male broilers (d 21 to 38). Four treatment groups were given the experimental diets containing 0, 60, 120, or 180 parts per million (ppm) salinomycin from d 21 to 38. Performance, relative organ weights, selected serum enzymes, and salinomycin residues in liver, muscle, and serum were determined. Salinomycin supplementation had no effect on body weight, feed intake, or feed conversion, and caused no overt signs of toxicity. After a week of being fed the salinomycin diets, the serum activity of aspartate aminotransferase was significantly increased in chickens fed 180 ppm compared with controls. These birds also showed microscopic lesions in breast and thigh muscles, but not in cardiac muscle. Salinomycin residues were not detected by high-performance liquid chromatography coupled to tandem mass spectrometry in liver or muscle samples from the birds fed 0, 60, or 120 ppm salinomycin. However, chickens fed 180 ppm salinomycin had detectable levels in liver and muscle above the maximum residue level of 5 µg/kg established by the European Union. All birds fed salinomycin had salinomycin in their sera with levels ranging from N.D. (not detected) in the controls to 24.4 ± 7.9, 61.4 ± 18.9, and 94.5 ± 9.1 µg/L for salinomycin dietary levels of 60, 120, and 180 ppm, respectively. Serum salinomycin concentration was linearly related with salinomycin content in feed (y = 0.584x - 10, r2 = 0.999). The results showed that even at 3 times the prophylactic level, salinomycin does not induce clinical toxicosis or mortality. No salinomycin residues were found in edible tissues at the recommended dietary level or at 2 times this level. However, salinomycin was detected in serum regardless of the dietary level. A simple method for salinomycin determination in serum is described which can be used as a marker of exposure and/or to predict levels in the diet.

Content of the Saponin Protodioscin in Brachiaria spp. from the Eastern Plains of Colombia.

Protodioscin is used as a marker of saponin content that could cause hepatotoxicity in ruminants. In Brachiaria spp. from two regions of the Colombian Eastern Plains (east mountain range of the Andean-"piedemonte" and Ariari River Valley) were determined this metabolite at 14 and 28 days post-cutting under different climatic conditions. No protodioscin was detected in B. dictyoneura or B. humidicola. In B. brizantha, B. decumbens and B. ruziziensis x B. decumbens x B. brizantha (hybrid), protodioscin content corresponded to an interaction between species, post-cutting time and season. Concentrations ≥1% (minimum toxic level) were recorded in B. decumbens and the hybrid, and to a lesser extent in B. brizantha. The concentration of protodioscin was higher at 28 days, when the pastures are suitable for consumption. B. brizantha accumulated the lowest saponin concentration, whereas the hybrid had the highest levels, particularly in the "piedemonte" and during drought (3.37%). Dry season favored the protodioscin concentration in B. decumbens (in river valley) and in the hybrid (in "piedemonte"). In the latter, there was a positive correlation with temperature and a negative with humidity, which are typical characteristics of dry periods. This is the first report of protodioscin content in the hybrid.

Detection of Ptaquilosides in different phenologic stages of Bracken fern (Pteridium aquilinum) and analysis of mik samples in farms with hematuria in Tolima, Colombia / Detección de ptaquilósido en diferentes estados fenológicos de "helecho macho" (Pteridium aquilinum) y análisis de muestras de leche en granjas con hematuria en Tolima, Colombia / Detecção da ptaquilosida em diferentes estágios fenológicos da samambaia (Pteridiumaquilinum) e análise de amostras de leite em fazendas com hematúria em Tolima, Colômbia

Bracken fern or "Helecho Macho" (Pteridium aquilinum) is one of the most common weeds in the meadows of the mountain ranges of Colombia. Consumption of this palatable plant by bovines causes a disease known as bovine enzootic hematuria and esophageal neoplasia. The toxic effect of the plant in bovines is caused by the ptaquiloside, main carcinogenic toxin of this plant. In this study, eight samples of Bracken fern in different phenologic stages and 16 milk samples collected in two towns of Tolima, Líbano and Murillo, were analized. In both cases, Highperformance liquid cromatography (HPLC) coupled with Mass Spectrometry (MS) was used. In all Bracken fern samples analized, detectable levels of ptaquilosides were observed, ranging from 23 to 1194 µg/g, with a 342 µg/g mean. No detectable levels of ptaquilosides were found in the milk samples. The results show a great variation in the content of ptaquilosides depending on the phenologic stage and collection site of the plant. It is posible that the reported instability of the ptaquiloside and the processing given to the milk samples could have caused the lack of detection of the compound in milk

El "helecho macho" (Pteridium aquilinum) es una de las malezas más comunes en praderas de la región de cordillera en Colombia. El consumo de esta planta palatable por parte de los bovinos causa una enfermedad conocida como hematuria enzoótica bovina y neoplasias de esófago. El efecto tóxico de la planta en los bovinos es causado por el ptaquilósido, principal toxina carcinogénica de esta planta. En el presente estudio se analizaron ocho muestras en diferentes estados fenológicos del helecho obtenidas en dos municipios del departamento del Tolima (Líbano y Murillo) y 16 muestras de leche de la misma zona. En ambos casos se utilizó como técnica analítica cromatografía líquida de alta eficiencia (HPLC) acoplada a espectrometría de masas (MS). En todas las muestras analizadas se observaron niveles detectables de ptaquilósido, con un rango de 23 a 1.194 µg/g y un promedio de 342 µg/g. No se encontraron niveles detectables de ptaquilósido en ninguna de las muestras de leche. Los resultados del estudio muestran la gran variación en el contenido de ptaquilósido dependiendo del estado fenológico de la planta y del sitio de colecta. Es posible que la reportada inestabilidad del ptaquilósido y el tipo de procesamiento dado a las muestras de leche haya ocasionado la no detección del compuesto en las mismas.

A samambaia (Pteridium aquilinum) é uma das ervas daninhas mais comuns nas pastagens na região de cordilheira na Colômbia. O consumo desta planta palatável para os bovinos, causa uma doença conhecida como hematúria enzoótica bovina e neoplasias de esôfago. O efeito tóxico da planta nos bovinos é causado pelo ptaquilosídeo, principal toxina carcinogênica desta planta. No presente estudo foram analisadas oito amostras em diferentes estágios fenológicos da samambaia e 16 amostras de leite obtidas em dois municípios do departamento de Tolima (Líbano e Murillo). Em ambos os casos foi utilizada como técnica analítica a cromatografia líquida de alta eficiência (HPLC) acoplada a espectrometria de massas (MS). Em todas as amostras analisadas foram observados níveis detectáveis de ptaquilosídeo, com um rango de 23 a 1.194 µg/g e uma média de 342 µg/g. Não foram encontrados níveis detectáveis de ptaquilosídeo em nenhuma das amostras de leite. Os resultados do estudo mostram a grande variação no conteúdo de ptaquilosídeo dependendo do estágio fenológico da planta e do local da coleta. É possível que a reportada instabilidade do ptaquilosídeo e o tipo de processamento dado às amostras de leite seja a causa da falta de detecção do composto nas amostras de leite analisadas.

Toxicosis by Plant Alkaloids in Humans and Animals in Colombia.

Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia.

Mycotoxins and cyanogenic glycosides in staple foods of three indigenous people of the Colombian Amazon.

A study was conducted to determine the incidence and levels of mycotoxins in the main staple foods of three indigenous people of the Colombian Amazon. A total of 20 corn, 24 rice and 59 cassava samples were analysed by a multi-analyte liquid chromatography-tandem mass spectrometry method covering the major classes of mycotoxins. In addition, cassava samples were also analysed for cyanogenic glycosides. The indigenous Amazon communities tested are exposed to potentially carcinogenic mycotoxins (particularly aflatoxins), as well as other mycotoxins, mainly through the intake of locally grown corn. Citrinin content in this corn was unusually high and has not been reported elsewhere. Two cassava samples contained high levels of cyanogenic glycosides. It is strongly recommended not to grow corn in the Amazon but instead purchase it from vendors capable of guaranteeing mycotoxin levels below the maximum allowable concentration in Colombia.

Determination of aflatoxin M1 in breast milk as a biomarker of maternal and infant exposure in Colombia.

Chronic exposure to aflatoxins, and especially to aflatoxin B1 (AFB1), causes hepatocellular carcinoma with prevalence 16-32 times higher in developing compared with developed countries. Aflatoxin M1 (AFM1) is a monohydroxylated metabolite from AFB1 that is secreted in milk and which can be used as a biomarker of AFB1 exposure. This study aimed to determine AFM1 levels in human breast milk using immunoaffinity column clean-up with HPLC and fluorescence detection. Breast milk samples were obtained from 50 nursing mothers. Volunteers filled in a questionnaire giving their consent to analyse their samples as well as details of their socioeconomic, demographic and clinical data. The possible dietary sources of aflatoxins were assessed using a food frequency questionnaire. A total of 90% of the samples tested positive for AFM1, with a mean of 5.2 ng l(-1) and a range of 0.9-18.5 ng l(-1). The study demonstrated a high frequency of exposure of mothers and neonates to AFB1 and AFM1 in Colombia, and it points out the need to regulate and monitor continuously the presence of aflatoxins in human foods. Further research is needed in order to determine the presence of other mycotoxins in foods and in human samples as well as to devise protection strategies in a country where mycotoxins in human foods are commonly found.