Tissue damage and embryonic malformation induced by aqueous extract of Pteridium aquilinum on chorioallantoic membrane of chick embryo (CAM) / Danos teciduais e mal formações morfológicas induzidas pelo extrato aquoso de Pteridium aquilinum sobre a membrana corioalantóica (CAM) e o embrião de galinha

The aim of this study was evaluate the effects of Bracken fern (BF) (Pteridium aquilinum (L.) Kuhn.) on biological systems. When consumed by animals can cause acute intoxication, hematuria, biochemistry alterations and cancer. To humans the toxicity is associated with its intake on contaminated ground water or milk and inhalation of its spores. In order to check the BF aqueous extract (AEB) deleterious effects on animals blood vessels system, chick embryo chorioallantoic membrane (CAM) was used. It were applying on CAM 0.1, 0.5, 1, 5, 10 e 15 µg/mL of AEB and saline as control. The angiogenesis was analyzed and the vascular density index (VDI) calculated. The CAM samples were prepared and stained with H&E to evaluation of microvessels, Massons trichrome to characterize collagen and fibrin deposition and Picro-sirius used to evaluate collagen using polarized light. Also the morphological aspects of embryos were analysed. We observe on the results of neovascularization that AEB did not change significantly the number of vessels/mm², however, membranes treated with AEB (5 or 10 µg/ mL) exhibit opacity and tissue fibrosis, both signs of inflammation. Histological analysis with Massons trichrome and picro-sirius on tissues exposed to AEB respectively has shown increased collagen fibers and presence of fibrilar collagen. The embryos exposed to concentrations of 5 or 10 μg/mL AEB, showed changes as poor face formation and poor closing of abdominal wall. The highest concentration of AEB (15 μg/mL) was lethal to embryos. Although significant effects on the CAMs vasculature has not observed, tissue aggression was detected, a desmoplasia (an extensive inflammatory signal triggered by tissue injury), changes caused on embryos as well as the presence of toxic substances in the AEB show us an important and deleterious pathway of this bracken fern extract on its intoxicants effects on humans and animals, and even cancer or the death of animals.(AU)

O foco principal desse estudo foi avaliar os efeitos do extrato aquoso de Samambaia (EAS) (Pteridium aquilinum (L.) Kuhn) sobre sistemas biológicos. A ingestão das folhas de Samambaia pode provocar intoxicação aguda, hematúria, alterações bioquímicas e câncer se consumida por animais. Em humanos também pode provocar intoxicação ao ser ingerida com água ou leite contaminados e pela inalação de seus esporos. Considerando os efeitos danosos provocados pelo consumo dessa planta esse estudo analisou a ação do EAS sobre um sistema de vasos sanguíneos, a membrana corioalantóide (MCA) de embrião de galinha. Sobre a MCA foram aplicados 0,1, 0,5, 1, 5, 10 e 15 µg/mL de EAS, salina como controle. A angiogênese foi analisada e o índice de densidade vascular (IDV) calculado. Amostras da CAM foram coradas com H&E para avaliação de microvasos, Tricrômico de Masson para caracterização de colágeno e deposição de fibrina e Picro-sirius para analisar o colágeno através de luz polarizada. Os aspectos morfológicos dos embriões também foram analisados. Os resultados da neovascularização mostraram que não houve mudança significativa do número de vasos/mm². Entretanto, as membranas tratadas com 5 ou 10 µg/mL EAS exibiram uma opacidade junto com um tecido fibroso, ambos sinais de inflamação. Corroborando, as análises com Tricrômico Masson e Picro Sirius, respectivamente, apontaram para um aumento das fibras colágenas e presença de colágeno fibrilar. Embriões expostos às concentrações de 5 e 10 μg/mL do EAS sofreram malformações na face e na parede tóraco-abdominal. A concentração de 15 μg/mL foi letal para os embriões. Embora efeitos significativos na vasculatura da MCA não tenham ocorrido, observou-se desmoplasia (um grande sinal de inflamação). Esse fato, juntamente com as malformações no embrião e a presença de compostos tóxicos no EAS inferem, se a planta for ingerida, uma via importante para explicar a intoxicação de animais e humanos, e até mesmo o câncer ou a morte de animais.(AU)

Tissue damage and embryonic malformation induced by aqueous extract of Pteridium aquilinum on chorioallantoic membrane of chick embryo (CAM) / Danos teciduais e mal formações morfológicas induzidas pelo extrato aquoso de Pteridium aquilinum sobre a membrana corioalantóica (CAM) e o embrião de galinha

The aim of this study was evaluate the effects of Bracken fern (BF) (Pteridium aquilinum (L.) Kuhn.) on biological systems. When consumed by animals can cause acute intoxication, hematuria, biochemistry alterations and cancer. To humans the toxicity is associated with its intake on contaminated ground water or milk and inhalation of its spores. In order to check the BF aqueous extract (AEB) deleterious effects on animals blood vessels system, chick embryo chorioallantoic membrane (CAM) was used. It were applying on CAM 0.1, 0.5, 1, 5, 10 e 15 µg/mL of AEB and saline as control. The angiogenesis was analyzed and the vascular density index (VDI) calculated. The CAM samples were prepared and stained with H&E to evaluation of microvessels, Masson’s trichrome to characterize collagen and fibrin deposition and Picro-sirius used to evaluate collagen using polarized light. Also the morphological aspects of embryos were analysed. We observe on the results of neovascularization that AEB did not change significantly the number of vessels/mm², however, membranes treated with AEB (5 or 10 µg/ mL) exhibit opacity and tissue fibrosis, both signs of inflammation. Histological analysis with Masson’s trichrome and picro-sirius on tissues exposed to AEB respectively has shown increased collagen fibers and presence of fibrilar collagen. The embryos exposed to concentrations of 5 or 10 μg/mL AEB, showed changes as poor face formation and poor closing of abdominal wall. The highest concentration of AEB (15 μg/mL) was lethal to embryos. Although significant effects on the CAM’s vasculature has not observed, tissue aggression was detected, a desmoplasia (an extensive inflammatory signal triggered by tissue injury), changes caused on embryos as well as the presence of toxic substances in the AEB show us an important and deleterious pathway of this bracken fern extract on its intoxicants effects on humans and animals, and even cancer or the death of animals.

O foco principal desse estudo foi avaliar os efeitos do extrato aquoso de Samambaia (EAS) (Pteridium aquilinum (L.) Kuhn) sobre sistemas biológicos. A ingestão das folhas de Samambaia pode provocar intoxicação aguda, hematúria, alterações bioquímicas e câncer se consumida por animais. Em humanos também pode provocar intoxicação ao ser ingerida com água ou leite contaminados e pela inalação de seus esporos. Considerando os efeitos danosos provocados pelo consumo dessa planta esse estudo analisou a ação do EAS sobre um sistema de vasos sanguíneos, a membrana corioalantóide (MCA) de embrião de galinha. Sobre a MCA foram aplicados 0,1, 0,5, 1, 5, 10 e 15 µg/mL de EAS, salina como controle. A angiogênese foi analisada e o índice de densidade vascular (IDV) calculado. Amostras da CAM foram coradas com H&E para avaliação de microvasos, Tricrômico de Masson para caracterização de colágeno e deposição de fibrina e Picro-sirius para analisar o colágeno através de luz polarizada. Os aspectos morfológicos dos embriões também foram analisados. Os resultados da neovascularização mostraram que não houve mudança significativa do número de vasos/mm². Entretanto, as membranas tratadas com 5 ou 10 µg/mL EAS exibiram uma opacidade junto com um tecido fibroso, ambos sinais de inflamação. Corroborando, as análises com Tricrômico Masson e Picro Sirius, respectivamente, apontaram para um aumento das fibras colágenas e presença de colágeno fibrilar. Embriões expostos às concentrações de 5 e 10 μg/mL do EAS sofreram malformações na face e na parede tóraco-abdominal. A concentração de 15 μg/mL foi letal para os embriões. Embora efeitos significativos na vasculatura da MCA não tenham ocorrido, observou-se desmoplasia (um grande sinal de inflamação). Esse fato, juntamente com as malformações no embrião e a presença de compostos tóxicos no EAS inferem, se a planta for ingerida, uma via importante para explicar a intoxicação de animais e humanos, e até mesmo o câncer ou a morte de animais.

Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.

The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant's dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of allelopathy in the dominance processes of this plant in the areas where it occurs.

Palynological analysis of Dennstaedtiaceae taxa from the Paranaense Phytogeographic Province that produce Trilete spores II: Microlepia speluncae and Pteridium arachnoideum.

The spore morphology and wall ultrastructure of Microlepia speluncae and Pteridium arachnoideum from the Paranaense Province were analyzed with LM, SEM and TEM and a comparative analysis was carried out. In both species the spores are covered by a three-dimensional network of threads branched and fused, tangentially arranged to the surface, and some free-end threads are also seen. The species were differentiated by morphology and the frequency of threads fusion and the networks distribution on the surface of the spores. In both species the exospore is two-layered in section, both layers are traversed by single or branched channels. The perispore is three-layered in section: the inner layer is adhered to the exospore, the middle layer is formed of a three-dimensional network of threads and the outer layer is discontinuous. The perispore ultrastructure of Microlepia speluncae was interpreted as formed of helical subunits displayed around a central channel. The spore morphology and perispore ultrastructure allow differentiating Microlepia from Pteridium but also to the other Dennstaedtiaceae genera that grow in the Paranaense Province. The results obtained allow establishing relationships that let us recognize different groups and gave a new reference to get a better knowledge of the family.

The role of Pteridium arachnoideum(Kaulf) on the seed bank of the endangered Brazilian Cerrado.

The native bracken (Pteridium arachnoideum) often occurs in mono-specific stands in the Brazilian Cerrado, and this dominance can impact on both the above-ground vegetation and soil seed bank. This study investigated how invasion by this species over a 20-year period changed the seed bank and the relationship between the seed bank and litter mass. We extracted soil samples from three replicated invaded and uninvaded sites, and followed seedling emergence for six months. We collected the above-ground biomass and litter of P. arachnoideum in ten 1m2 plots from three invaded sites. There was no difference between invaded and uninvaded areas in seed bank richness, diversity or overall abundance. The most abundant family was the Melastomataceae, followed by the Poaceae. The Melastomataceae was more abundant in uninvaded sites, but the most common species of this family (Tibouchinastenocarpa) was not affected. The grasses were more common in invaded sites in the rainy season and were affected by heterogeneity in the litter layer. The seed bank could play a role in the recovery of these invaded areas, but the presence of weeds and invasive grasses could constrain their use as a management strategy.

The role of Pteridium arachnoideum(Kaulf) on the seed bank of the endangered Brazilian Cerrado / Impacto de Pteridium arachnoideum(Kaulf) no banco de sementes do Cerrado

Abstract The native bracken (Pteridium arachnoideum) often occurs in mono-specific stands in the Brazilian Cerrado, and this dominance can impact on both the above-ground vegetation and soil seed bank. This study investigated how invasion by this species over a 20-year period changed the seed bank and the relationship between the seed bank and litter mass. We extracted soil samples from three replicated invaded and uninvaded sites, and followed seedling emergence for six months. We collected the above-ground biomass and litter of P. arachnoideum in ten 1m2 plots from three invaded sites. There was no difference between invaded and uninvaded areas in seed bank richness, diversity or overall abundance. The most abundant family was the Melastomataceae, followed by the Poaceae. The Melastomataceae was more abundant in uninvaded sites, but the most common species of this family (Tibouchinastenocarpa) was not affected. The grasses were more common in invaded sites in the rainy season and were affected by heterogeneity in the litter layer. The seed bank could play a role in the recovery of these invaded areas, but the presence of weeds and invasive grasses could constrain their use as a management strategy.

Resumo O samambaião (Pteridium arachnoideum) frequentemente domina áreas de cerrado, e pode alterar tanto a vegetação estabelecida quanto o banco de sementes do solo. Nesse estudo investigamos como áreas de cerrado invadidas por essa espécie a mais de 20 anos alteraram o banco de sementes, e também a relação entre banco de sementes e quantidade de serapilheira. Extraímos amostras de solo em três invadidas e em áreas controle adjacentes, e monitoramos a emergência de plântulas por seis meses. Coletamos a biomassa aérea e a serapilheira de P. arachnoideum em dez parcelas de 1m2 nas áreas invadidas. Ariqueza, diversidade e abundância totalnão diferiram entre áreas invadidas e controle. A família mais abundante foi Melastomataceae, seguida por Poaceae. Melastomataceae foi mais comum em áreas controle, mas não a espécie mais comum nessa família (Tibouchina stenocarpa). Gramíneas foram predominantes em áreas invadidas durante a estação chuvosa, e foram afetadas pela heterogeneidade da camada de serapilheira. O banco de sementes pode ser importante para a recuperação dessas áreas invadidas, mas esse uso pode ser prejudicado pela presença de ervas daninhas e gramíneas invasoras.

A comparative study of resource allocation in Pteridium in different Brazilian ecosystems and its relationship with European studies.

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentum subsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way in both Brazil and Europe, and that in Brazil fronds tend to be longer and heavier, presumably as a result of the continuous growing season in South America while is shortened in Europe by frost. The paper shows the ability of Pteridium to adapt to different ecosystems.

A comparative study of resource allocation in Pteridium in different Brazilian ecosystems and its relationship with European studies / Estudo comparativo da alocação de recurso em Pteridium em diferentes ecossistemas brasileiros e sua relação com estudos na europa

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentum subsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way in both Brazil and Europe, and that in Brazil fronds tend to be longer and heavier, presumably as a result of the continuous growing season in South America while is shortened in Europe by frost. The paper shows the ability of Pteridium to adapt to different ecosystems.(AU)

Pteridium é um gênero cosmopolita que inclui espécies invasoras em várias partes do mundo. Os estudos sobre o gênero têm ocorrido principalmente na Europa, e existem poucas informações para as espécies que ocorrem na América do Sul. Nesse estudo comparamos a alocação de biomassa de P. esculentum subsp. arachnoideum em dois ecossistemas brasileiros Mata Atlântica e Cerrado - em cada um dos quais medimos a biomassa nos rametas, nos rizomas e na serapilheira. Comparamos, também, a densidade, comprimento e biomassa dos rametas com informações obtidas sobre P. esculentum subsp. arachnoideum na Venezuela e P. aquilinum na Europa. P. esculentum subsp. arachnoideum apresentou respostas distintas. Encontramos uma relação negativa entre a biomassa de rametas e da serapilheira, indicando uma retro-alimentação negativa, enquanto houve uma relação positiva entre a biomassa dos rametas e dos rizomas. A comparação das relações entre os continentes indicou que Pteridium responde diferentemente no Brazil e na Europa, e também que no Brasil os rametas são maiores e contêm mais biomassa, possivelmente devido à estação de crescimento contínua, enquanto na Europa o crescimento é limitado pelas baixas temperaturas. Esse estudo demonstra o sucesso adaptativo de Pteridium em diferentes ecossistemas.(AU)

A comparative study of resource allocation in Pteridium in different Brazilian ecosystems and its relationship with European studies / Estudo comparativo da alocação de recurso em Pteridium em diferentes ecossistemas brasileiros e sua relação com estudos na europa

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentum subsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way in both Brazil and Europe, and that in Brazil fronds tend to be longer and heavier, presumably as a result of the continuous growing season in South America while is shortened in Europe by frost. The paper shows the ability of Pteridium to adapt to different ecosystems.

Pteridium é um gênero cosmopolita que inclui espécies invasoras em várias partes do mundo. Os estudos sobre o gênero têm ocorrido principalmente na Europa, e existem poucas informações para as espécies que ocorrem na América do Sul. Nesse estudo comparamos a alocação de biomassa de P. esculentum subsp. arachnoideum em dois ecossistemas brasileiros – Mata Atlântica e Cerrado - em cada um dos quais medimos a biomassa nos rametas, nos rizomas e na serapilheira. Comparamos, também, a densidade, comprimento e biomassa dos rametas com informações obtidas sobre P. esculentum subsp. arachnoideum na Venezuela e P. aquilinum na Europa. P. esculentum subsp. arachnoideum apresentou respostas distintas. Encontramos uma relação negativa entre a biomassa de rametas e da serapilheira, indicando uma retro-alimentação negativa, enquanto houve uma relação positiva entre a biomassa dos rametas e dos rizomas. A comparação das relações entre os continentes indicou que Pteridium responde diferentemente no Brazil e na Europa, e também que no Brasil os rametas são maiores e contêm mais biomassa, possivelmente devido à estação de crescimento contínua, enquanto na Europa o crescimento é limitado pelas baixas temperaturas. Esse estudo demonstra o sucesso adaptativo de Pteridium em diferentes ecossistemas.