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[PMID]:27716466
[Au] Autor:Clauson-Kaas F; Ramwell C; Hansen HCB; Strobel BW
[Ad] Endereço:Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Denmark; Centre for Chemical Safety and Stewardship, Fera Science Ltd., Sand Hutton, York, YO41 1LZ, United Kingdom. Electronic address: pfck@plen.ku.dk.
[Ti] Título:Ptaquiloside from bracken in stream water at base flow and during storm events.
[So] Source:Water Res;106:155-162, 2016 Dec 01.
[Is] ISSN:1879-2448
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The bracken fern (Pteridium spp.) densely populates both open and woodland vegetation types around the globe. Bracken is toxic to livestock when consumed, and a group of potent illudane-type carcinogens have been identified, of which the compound ptaquiloside (PTA) is the most abundant. The highly water soluble PTA has been shown to be leachable from bracken fronds, and present in the soil and water below bracken stands. This has raised concerns over whether the compound might pose a risk to drinking water sources. We investigated PTA concentrations in a small stream draining a bracken-infested catchment at base flow and in response to storm events during a growth season, and included sampling of the bracken canopy throughfall. Streams in other bracken-dominated areas were also sampled at base flow for comparison, and a controlled pulse experiment was conducted in the field to study the in-stream dynamics of PTA. Ptaquiloside concentrations in the stream never exceeded 61 ng L in the base flow samples, but peaked at 2.2 µg L during the studied storm events. The mass of PTA in the stream, per storm event, was 7.5-93 mg from this catchment. A clear temporal connection was observed between rainfall and PTA concentration in the stream, with a reproducible time lag of approx. 1 h from onset of rain to elevated concentrations, and returning rather quickly (about 2 h) to base flow concentration levels. The concentration of PTA behaved similar to an inert tracer (Cl ) in the pulse experiment over a relative short time scale (minutes-hours) reflecting no PTA sorption, and dispersion and dilution considerably lowered the observed PTA concentrations downstream. Bracken throughfall revealed a potent and lasting source of PTA during rainfall, with concentrations up to 169 µg L , that did not decrease over the course of the event. In the stream, the throughfall contribution to PTA cannot be separated from a possible below-ground input from litter, rhizomes and soil. Catchment-specific factors such as the soil pH, topography, hydrology, and bracken coverage will evidently affect the level of PTA observed in the receiving stream, as well as the distance from bracken, but time since precipitation seems most important. Studying PTA loads and transport in surface streams fed by bracken-infested catchments, simply taking occasional grab samples will not capture the precipitation-linked pulses. The place and time of sampling governs the findings, and including event-based sampling is essential to provide a more complete picture of PTA loads to surface water.
[Mh] Termos MeSH primário: Pteridium
Água
[Mh] Termos MeSH secundário: Carcinógenos
Chuvas
Solo/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carcinogens); 0 (Soil); 059QF0KO0R (Water)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161008
[St] Status:MEDLINE


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[PMID]:27677121
[Au] Autor:Skourti-Stathaki E; Clauson-Kaas F; Brandt KK; Rasmussen LH; Hansen HCB
[Ad] Endereço:Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C., Denmark.
[Ti] Título:Dissipation of pterosin B in acid soils - Tracking the fate of the bracken fern carcinogen ptaquiloside.
[So] Source:Chemosphere;165:453-459, 2016 Dec.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bracken ferns (Pteridium spp.) are well-known for their carcinogenic properties, which are ascribed to the content of ptaquiloside and ptaquiloside-like substances. Ptaquiloside leach from the ferns and may cause contamination of drinking water. Pterosin B is formed by hydrolysis of ptaquiloside. In soil, Pterosin B is adsorbed more strongly and it is expected to have a slower turnover than ptaquiloside. We thus hypothesized that pterosin B may serve as an indicator for any past presence of ptaquiloside. Pterosin B degradation was studied in acid forest soils from bracken-covered and bracken-free areas. Soil samples were incubated with pterosin B at 3 and 8 µg g for 10 days, whereas sterile (autoclaved) samples were incubated for 23 days. Pterosin B showed unexpected fast degradation in soils with full degradation in topsoils in 2-5 days. Pterosin B dissipation followed the sum of two-first order reactions. The initial fast reaction with half-lives of 0.7-3.5 h contributed 11-59% of the total pterosin B degradation, while the slow reaction was 20-100 times slower than the fast reaction. Total dissipation half-lives were shorter for loamy sand (4 h) than for sandy loam soils (28 h). No degradation of pterosin B took place under sterile conditions assuming observed dissipation during the first 3 h could be attributed to irreversible sorption. Our results demonstrate that pterosin B is microbially degraded and that pterosin B is as unstable as ptaquiloside and hence cannot be used as an indicator for former presence of ptaquiloside in soil.
[Mh] Termos MeSH primário: Carcinógenos/química
Indanos/química
Pteridium/química
Sesquiterpenos/química
Poluentes do Solo/química
[Mh] Termos MeSH secundário: Concentração de Íons de Hidrogênio
Hidrólise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carcinogens); 0 (Indans); 0 (Sesquiterpenes); 0 (Soil Pollutants); 0 (pterosin B); F0MN9S5699 (ptaquiloside)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:171008
[Lr] Data última revisão:
171008
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160928
[St] Status:MEDLINE


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[PMID]:27640346
[Au] Autor:Santos C; Ferreirinha P; Sousa H; Ribeiro J; Bastos MM; Neto T; Oliveira PA; Medeiros R; Vilanova M; Gil da Costa RM
[Ad] Endereço:ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal. Electronic address: carlos.e.santos792@gmail.com.
[Ti] Título:Ptaquiloside from bracken (Pteridium spp.) inhibits tumour-infiltrating CD8 T cells in HPV-16 transgenic mice.
[So] Source:Food Chem Toxicol;97:277-285, 2016 Nov.
[Is] ISSN:1873-6351
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bracken is a fern with worldwide distribution. Exposure to bracken toxins such as ptaquiloside is hypothesized to increase the risk of papillomavirus-related cancers of the upper digestive tract. Ptaquiloside is thought to be an immunosupressor, thus allowing for the development of viral lesions. We have used a human papillomavirus type 16-transgenic (K14-HPV16) mouse model to study the effects of ptaquiloside on tumour-infiltrating CD8 T lymphocytes, which are critical players in anti-tumour immunity. HPV16 mice received ptaquiloside (0.5 mg/mouse/week) for 10 weeks. These were then euthanized at 30 weeks of age, along with age-matched untreated controls. Skin samples were enzymatically digested and CD8 T cells analysed for CD107a and CD44 surface expression. Ptaquiloside-exposed HPV16 mice showed a significantly decreased percentage (P < 0.05) of CD8 CD107a and CD8 CD44  T cells when compared with untreated HPV16 animals. Histologically, 100% of ptaquilosidetreated mice showed diffuse epidermal dysplasia, compared with 50% of the untreated mice. These findings suggest that ptaquiloside exerts an immunosuppressive role by decreasing CD8 T cell activation and degranulation in HPV-induced lesions. Given the key role of CD8 T lymphocytes against HPV-induced lesions, this effect is likely to contribute for viral persistence, tumour progression and increased aggressiveness in patients with HPV-related malignancies.
[Mh] Termos MeSH primário: Linfócitos T CD8-Positivos/efeitos dos fármacos
Papillomavirus Humano 16/patogenicidade
Indanos/toxicidade
Infecções por Papillomavirus/complicações
Pteridium/química
Sesquiterpenos/toxicidade
Dermatopatias/etiologia
Neoplasias do Colo do Útero/etiologia
[Mh] Termos MeSH secundário: Animais
Linfócitos T CD8-Positivos/imunologia
Carcinógenos/toxicidade
Feminino
Citometria de Fluxo
Seres Humanos
Camundongos
Camundongos Transgênicos
Infecções por Papillomavirus/imunologia
Infecções por Papillomavirus/virologia
Dermatopatias/patologia
Neoplasias do Colo do Útero/patologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carcinogens); 0 (Indans); 0 (Sesquiterpenes); F0MN9S5699 (ptaquiloside)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170309
[Lr] Data última revisão:
170309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160920
[St] Status:MEDLINE


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[PMID]:27552161
[Au] Autor:de Jesus Jatoba L; Varela RM; Molinillo JM; Ud Din Z; Juliano Gualtieri SC; Rodrigues-Filho E; Macías FA
[Ad] Endereço:Laboratory of Plant Phytochemical and Reproductive Ecophysiology Studies, Department of Botany, Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
[Ti] Título:Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.
[So] Source:PLoS One;11(8):e0161670, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo: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.
[Mh] Termos MeSH primário: Alelopatia
Pteridium/química
Pteridium/fisiologia
[Mh] Termos MeSH secundário: Antibiose
Brasil
Estrutura Molecular
Compostos Fitoquímicos/química
Compostos Fitoquímicos/toxicidade
Extratos Vegetais/química
Extratos Vegetais/toxicidade
Raízes de Plantas/química
Raízes de Plantas/citologia
Raízes de Plantas/crescimento & desenvolvimento
Proantocianidinas
Sesamum/crescimento & desenvolvimento
Solo/química
Triticum/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Phytochemicals); 0 (Plant Extracts); 0 (Proanthocyanidins); 0 (Soil); 18206-61-6 (proanthocyanidin)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160824
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0161670


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[PMID]:27177933
[Au] Autor:Mohammad RH; Nur-E-Alam M; Lahmann M; Parveen I; Tizzard GJ; Coles SJ; Fowler M; Drake AF; Heyes D; Thoss V
[Ad] Endereço:School of Chemistry, Bangor University, Bangor LL57 2UW, UK.
[Ti] Título:Isolation and characterisation of 13 pterosins and pterosides from bracken (Pteridium aquilinum (L.) Kuhn) rhizome.
[So] Source:Phytochemistry;128:82-94, 2016 Aug.
[Is] ISSN:1873-3700
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Systematic phytochemical investigations of the underground rhizome of Pteridium aquilinum (L.) Kuhn (Dennstaedtiaceae) afforded thirty-five pterosins and pterosides. By detailed analysis of one- and two-dimensional nuclear magnetic resonance spectroscopy, circular dichroism (CD) and high-resolution mass spectrometric data, thirteen previously undescribed pterosins and pterosides have been identified. Interestingly, for the first time 12-O-ß-D-glucopyranoside substituted pterosins, rhedynosides C and D, and the sulfate-containing pterosin, rhedynosin H, alongside the two known compounds, histiopterosin A and (2S)-pteroside A2, were isolated from the rhizomes of subsp. aquilinum of bracken. In addition, six-membered cyclic ether pterosins and pterosides, rhedynosin A and rhedynoside A, are the first examples of this type of pterosin-sesquiterpenoid. Additionally, the three previously reported compounds (rhedynosin I, (2S)-2-hydroxymethylpterosin E and (2S)-12-hydroxypterosin A) were obtained for the first time from plants as opposed to mammalian metabolic products. Single crystal X-ray diffraction analysis was applied to the previously undescribed compounds (2R)-rhedynoside B, (2R)-pteroside B and (2S)-pteroside K, yielding the first crystal structures for pterosides, and three known pterosins, (2S)-pterosin A, trans-pterosin C and cis-pterosin C. Rhedynosin C is the only example of the cyclic lactone pterosins with a keto group at position C-14. Six selected pterosins ((2S)-pterosin A, (2R)-pterosin B and trans-pterosin C) and associated glycosides ((2S)-pteroside A, (2R)-pteroside B and pteroside Z) were assessed for their anti-diabetic activity using an intestinal glucose uptake assay; all were found to be inactive at 300 µM.
[Mh] Termos MeSH primário: Glicosídeos/isolamento & purificação
Indanos/isolamento & purificação
Pteridium/química
Rizoma/química
Sesquiterpenos/isolamento & purificação
[Mh] Termos MeSH secundário: Animais
Diabetes Mellitus/tratamento farmacológico
Glicosídeos/química
Indanos/química
Ressonância Magnética Nuclear Biomolecular
Sesquiterpenos/química
Sesquiterpenos/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glycosides); 0 (Indans); 0 (Sesquiterpenes); 0 (pterosin); 62043-50-9 (pterosides)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170209
[Lr] Data última revisão:
170209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160515
[St] Status:MEDLINE


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[PMID]:27128893
[Au] Autor:O'Driscoll C; Ramwell C; Harhen B; Morrison L; Clauson-Kaas F; Hansen HC; Campbell G; Sheahan J; Misstear B; Xiao L
[Ad] Endereço:Department of Civil, Structural and Environmental Engineering, Trinity College Dublin, Dublin 2, Ireland. connieodriscoll@gmail.com.
[Ti] Título:Ptaquiloside in Irish Bracken Ferns and Receiving Waters, with Implications for Land Managers.
[So] Source:Molecules;21(5), 2016 Apr 26.
[Is] ISSN:1420-3049
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Ptaquiloside, along with other natural phytotoxins, is receiving increased attention from scientists and land use managers. There is an urgent need to increase empirical evidence to understand the scale of phytotoxin mobilisation and potential to enter into the environment. In this study the risk of ptaquiloside to drinking water was assessed by quantifying ptaquiloside in the receiving waters at three drinking water abstraction sites across Ireland and in bracken fronds surrounding the abstraction sites. We also investigated the impact of different management regimes (spraying, cutting and rolling) on ptaquiloside concentrations at plot-scale in six locations in Northern Ireland, UK. Ptaquiloside concentrations were determined using recent advances in the use of LC-MS for the detection and quantification of ptaquiloside. The results indicate that ptaquiloside is present in bracken stands surrounding drinking water abstractions in Ireland, and ptaquiloside concentrations were also observed in the receiving waters. Furthermore, spraying was found to be the most effective bracken management regime observed in terms of reducing ptaquiloside load. Increased awareness is vital on the implications of managing land with extensive bracken stands.
[Mh] Termos MeSH primário: Água Potável/química
Indanos/análise
Pteridium/química
Sesquiterpenos/análise
[Mh] Termos MeSH secundário: Cromatografia Gasosa-Espectrometria de Massas
Irlanda
Poluentes Químicos da Água/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Drinking Water); 0 (Indans); 0 (Sesquiterpenes); 0 (Water Pollutants, Chemical); F0MN9S5699 (ptaquiloside)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170306
[Lr] Data última revisão:
170306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160430
[St] Status:MEDLINE


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[PMID]:26970301
[Au] Autor:Itoh Y; Fuchino H; Sanosaka M; Kako K; Hada K; Fukamizu A; Takemori H; Kawahara N
[Ad] Endereço:Cell Signaling and Metabolic Disease, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, 567-0085, Japan.
[Ti] Título:Pterosin B has multiple targets in gluconeogenic programs, including coenzyme Q in RORα-SRC2 signaling.
[So] Source:Biochem Biophys Res Commun;473(2):415-20, 2016 Apr 29.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Hepatic gluconeogenic programs are regulated by a variety of signaling cascades. Glucagon-cAMP signaling is the main initiator of the gluconeogenic programs, including glucose-6-phosphatase catalytic subunit (G6pc) gene expression. Pterosin B, an ingredient in Pteridium aquilinum, inhibits salt-inducible kinase 3 signaling that represses cAMP-response element-binding protein regulated transcription coactivator 2, an inducer of gluconeogenic programs. As the results, pterosin B promotes G6pc expression even in the absence of cAMP. In this work, however, we noticed that once cAMP signaling was initiated, pterosin B became a strong repressor of G6pc expression. The search for associated transcription factors for pterosin B actions revealed that retinoic acid receptor-related orphan receptor alpha-steroid receptor coactivator 2 (RORα-SRC2) complex on the G6pc promoter was the target. Meanwhile, pterosin B impaired the oxidation-reduction cycle of coenzyme Q in mitochondrial oxidative phosphorylation (OXPHOS); and antimycin A, an inhibitor of coenzyme Q: cytochrome c-oxidoreductase (termed mitochondrial complex III), also mimicked pterosin B actions on RORα-SRC2 signaling. Although other respiratory toxins (rotenone and oligomycin) also suppressed G6pc expression accompanied by lowered ATP levels following the activation of AMP-activated kinase, minimal or no effect of these other toxins on RORα-SRC2 activity was observed. These results suggested that individual components in OXPHOS differentially linked to different transcriptional machineries for hepatic gluconeogenic programs, and the RORα-SRC2 complex acted as a sensor for oxidation-reduction cycle of coenzyme Q and regulated G6Pc expression. This was a site disrupted by pterosin B in gluconeogenic programs.
[Mh] Termos MeSH primário: Gluconeogênese/efeitos dos fármacos
Hepatócitos/efeitos dos fármacos
Indanos/farmacologia
Coativador 2 de Receptor Nuclear/metabolismo
Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo
Transdução de Sinais/efeitos dos fármacos
Ubiquinona/metabolismo
[Mh] Termos MeSH secundário: Animais
Linhagem Celular
Regulação da Expressão Gênica/efeitos dos fármacos
Glucose/metabolismo
Glucose-6-Fosfatase/genética
Hepatócitos/metabolismo
Indanos/química
Camundongos
Oxirredução/efeitos dos fármacos
Regiões Promotoras Genéticas/efeitos dos fármacos
Mapas de Interação de Proteínas/efeitos dos fármacos
Pteridium/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Indans); 0 (Nuclear Receptor Coactivator 2); 0 (Nuclear Receptor Subfamily 1, Group F, Member 1); 0 (Rora protein, mouse); 0 (pterosin B); 1339-63-5 (Ubiquinone); EC 3.1.3.9 (Glucose-6-Phosphatase); EC 3.1.3.9. (G6pc2 protein, mouse); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:160418
[Lr] Data última revisão:
160418
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160313
[St] Status:MEDLINE


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[PMID]:26871749
[Au] Autor:Xavier RO; Alday JG; Marrs RH; Matos DM
[Ad] Endereço:Departamento de Hidrobiologia, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
[Ti] Título:The role of Pteridium arachnoideum(Kaulf) on the seed bank of the endangered Brazilian Cerrado.
[So] Source:Braz J Biol;76(1):256-67, 2016 Feb.
[Is] ISSN:1678-4375
[Cp] País de publicação:Brazil
[La] Idioma:eng
[Ab] Resumo: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.
[Mh] Termos MeSH primário: Biodiversidade
Plantas
Pteridium/fisiologia
Sementes/fisiologia
[Mh] Termos MeSH secundário: Brasil
Estações do Ano
Solo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Soil)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160213
[St] Status:MEDLINE


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[PMID]:26632203
[Au] Autor:Oliveros-Bastidas A; Calcagno-Pissarelli MP; Naya M; Ávila-Núñez JL; Alonso-Amelot ME
[Ad] Endereço:Chemical Ecology Group, Faculty of Sciences, University of Los Andes, Mérida 5101, Venezuela.
[Ti] Título:Human gastric cancer, Helicobacter pylori and bracken carcinogens: A connecting hypothesis.
[So] Source:Med Hypotheses;88:91-9, 2016 Mar.
[Is] ISSN:1532-2777
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Long term infection of Helicobacter pylori (Hp) virulent strains is a key factor in the genesis of human gastric cancer, and so are certain dietary proinflammatory and genotoxic compounds. Carcinogenic bracken fern (Pteridium spp.) is one of these. Toxins from this plant are consumed as bracken culinary preparations, through milk and meat of bracken-exposed livestock, and drain waters from bracken swards. Bracken toxin ptaquiloside (PtQ), a suspected human carcinogen, elicits complex responses in animals leading to death. PtQ and Hp might cooperate in gastric pathologies. This paper presents an hypothesis on PtQ-Hp association leading to the enhancement of carcinogenesis in the human gastric environment that might explain the high gastric cancer incidence and death rates among Hp-infected people living in bracken zones at two levels: (1) The macroscopic scale comprising the flow of PtQ in the human diet. (2) the microscopic scale encompassing (A) gastric luminal medium; (B) gastric mucus structure and mucin degradation elicited by Hp; (C) bacterial pH gradient modification of the gastric mucosa that favors PtQ survival and its penetration into epithelial tissue; (D) combined PtQ/Hp effects on gastric immune and inflammatory responses; (E) PtQ-Hp complementary activity at selected cell signaling cascades and genome disturbance.
[Mh] Termos MeSH primário: Carcinógenos/química
Infecções por Helicobacter/complicações
Helicobacter pylori
Pteridium/química
Neoplasias Gástricas/complicações
Neoplasias Gástricas/microbiologia
[Mh] Termos MeSH secundário: Animais
Sobrevivência Celular
Dieta
Mucosa Gástrica/imunologia
Seres Humanos
Concentração de Íons de Hidrogênio
Sistema Imunitário
Imunidade Inata
Indanos/química
Inflamação
Razão de Chances
Pteridium/efeitos adversos
Sesquiterpenos/química
Transdução de Sinais
Neoplasias Gástricas/imunologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carcinogens); 0 (Indans); 0 (Sesquiterpenes); F0MN9S5699 (ptaquiloside)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170113
[Lr] Data última revisão:
170113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151204
[St] Status:MEDLINE


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[PMID]:26612497
[Au] Autor:Panneerselvam C; Murugan K; Roni M; Aziz AT; Suresh U; Rajaganesh R; Madhiyazhagan P; Subramaniam J; Dinesh D; Nicoletti M; Higuchi A; Alarfaj AA; Munusamy MA; Kumar S; Desneux N; Benelli G
[Ad] Endereço:Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641 046, Tamil Nadu, India.
[Ti] Título:Fern-synthesized nanoparticles in the fight against malaria: LC/MS analysis of Pteridium aquilinum leaf extract and biosynthesis of silver nanoparticles with high mosquitocidal and antiplasmodial activity.
[So] Source:Parasitol Res;115(3):997-1013, 2016 Mar.
[Is] ISSN:1432-1955
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum strains resistant to chloroquine. There is an urgent need to investigate new and effective sources of antimalarial drugs. This research proposed a novel method of fern-mediated synthesis of silver nanoparticles (AgNP) using a cheap plant extract of Pteridium aquilinum, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Phytochemical analysis of P. aquilinum leaf extract revealed the presence of phenols, alkaloids, tannins, flavonoids, proteins, carbohydrates, saponins, glycosides, steroids, and triterpenoids. LC/MS analysis identified at least 19 compounds, namely pterosin, hydroquinone, hydroxy-acetophenone, hydroxy-cinnamic acid, 5, 7-dihydroxy-4-methyl coumarin, trans-cinnamic acid, apiole, quercetin 3-glucoside, hydroxy-L-proline, hypaphorine, khellol glucoside, umbelliferose, violaxanthin, ergotamine tartrate, palmatine chloride, deacylgymnemic acid, methyl laurate, and palmitoyl acetate. In DPPH scavenging assays, the IC50 value of the P. aquilinum leaf extract was 10.04 µg/ml, while IC50 of BHT and rutin were 7.93 and 6.35 µg/ml. In mosquitocidal assays, LC50 of P. aquilinum leaf extract against Anopheles stephensi larvae and pupae were 220.44 ppm (larva I), 254.12 ppm (II), 302.32 ppm (III), 395.12 ppm (IV), and 502.20 ppm (pupa). LC50 of P. aquilinum-synthesized AgNP were 7.48 ppm (I), 10.68 ppm (II), 13.77 ppm (III), 18.45 ppm (IV), and 31.51 ppm (pupa). In the field, the application of P. aquilinum extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. Both the P. aquilinum extract and AgNP reduced longevity and fecundity of An. stephensi adults. Smoke toxicity experiments conducted against An. stephensi adults showed that P. aquilinum leaf-, stem-, and root-based coils evoked mortality rates comparable to the permethrin-based positive control (57, 50, 41, and 49 %, respectively). Furthermore, the antiplasmodial activity of P. aquilinum leaf extract and green-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of P. falciparum. IC50 of P. aquilinum were 62.04 µg/ml (CQ-s) and 71.16 µg/ml (CQ-r); P. aquilinum-synthesized AgNP achieved IC50 of 78.12 µg/ml (CQ-s) and 88.34 µg/ml (CQ-r). Overall, our results highlighted that fern-synthesized AgNP could be candidated as a new tool against chloroquine-resistant P. falciparum and different developmental instars of its primary vector An. stephensi. Further research on nanosynthesis routed by the LC/MS-identified constituents is ongoing.
[Mh] Termos MeSH primário: Antimaláricos/química
Inseticidas/química
Extratos Vegetais/química
Pteridium/química
Prata/toxicidade
[Mh] Termos MeSH secundário: Animais
Anopheles/efeitos dos fármacos
Anopheles/fisiologia
Antimaláricos/toxicidade
Seres Humanos
Inseticidas/toxicidade
Larva/efeitos dos fármacos
Malária/parasitologia
Malária/prevenção & controle
Nanopartículas/química
Extratos Vegetais/metabolismo
Folhas de Planta/química
Folhas de Planta/metabolismo
Plasmodium falciparum/efeitos dos fármacos
Plasmodium falciparum/fisiologia
Pteridium/metabolismo
Prata/química
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antimalarials); 0 (Insecticides); 0 (Plant Extracts); 3M4G523W1G (Silver)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:171007
[Lr] Data última revisão:
171007
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151128
[St] Status:MEDLINE
[do] DOI:10.1007/s00436-015-4828-x



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