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1.
Artigo em Inglês | MEDLINE | ID: mdl-31931331

RESUMO

Ptaquiloside (PTA) is an illudane glycoside partly responsible for the carcinogenicity of bracken ferns (Pteridium sp.). The PTA analogues ptesculentoside (PTE) and caudatoside (CAU) have similar biochemical reactivity. However, both compounds are highly under-investigated due to the lack of analytical standards and appropriate methods. This study presents a robust method for preparation of analytical standards of PTE, CAU, PTA, the corresponding hydrolysis products: pterosins G, A and B, and an LC-MS based method for simultaneous quantification of the six compounds in bracken. The chromatographic separation of analytes takes 5 min. The observed linear range of quantification was 20-500 µg/L for PTA and pterosin B, and 10-250 µg/L for the remaining compounds (r > 0.999). The limits of detection were 0.08-0.26 µg/L for PTE, CAU and PTA and 0.01-0.03 µg/L for the pterosins, equivalent to 2.0-6.5 µg/g and 0.25-0.75 µg/g in dry weight, respectively. The method was applied on 18 samples of dried fern leaves from 6 continents. Results demonstrated high variation in concentrations of PTE, CAU and PTA with levels prior to hydrolysis up to 3,900, 2,200 and 2,100 µg/g respectively. This is the first analytical method for simultaneous and direct measurement of all six compounds. Its application demonstrated that bracken ferns contain significant amounts of PTE and CAU relative to PTA.


Assuntos
Cromatografia Líquida/métodos , Glicosídeos , Indanos , Pteridium/química , Sesquiterpenos , Glicosídeos/análise , Glicosídeos/química , Indanos/análise , Indanos/química , Limite de Detecção , Modelos Lineares , Espectrometria de Massas/métodos , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Extratos Vegetais/química , Sesquiterpenos Policíclicos/análise , Sesquiterpenos Policíclicos/química , Reprodutibilidade dos Testes , Sesquiterpenos/análise , Sesquiterpenos/química
2.
PLoS One ; 14(6): e0218628, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31226154

RESUMO

Ptaquiloside is a natural toxin present in bracken ferns (Pteridium sp.). Cattle ingesting bracken may develop bladder tumours and excrete genotoxins in meat and milk. However, the fate of ptaquiloside in cattle and the link between ptaquiloside and cattle carcinogenesis is unresolved. Here, we present the toxicokinetic profile of ptaquiloside in plasma and urine after intravenous administration of ptaquiloside and after oral administration of bracken. Administered intravenously ptaquiloside, revealed a volume of distribution of 1.3 L kg-1 with a mean residence-time of 4 hours. A large fraction of ptaquiloside was converted to non-toxic pterosin B in the blood stream. Both ptaquiloside and pterosin B were excreted in urine (up to 41% of the dose). Oral administration of ptaquiloside via bracken extract or dried ferns did not result in observations of ptaquiloside in body fluids, indicating deglycosolidation in the rumen. Pterosin B was detected in both plasma and urine after oral administration. Hence, transport of carcinogenic ptaquiloside metabolites over the rumen membrane is indicated. Pterosin B recovered from urine counted for 7% of the dose given intravenously. Heifers exposed to bracken for 7 days (2 mg ptaquiloside kg-1) developed preneoplastic lesions in the urinary bladder most likely caused by genotoxic ptaquiloside metabolites.


Assuntos
Carcinógenos/farmacocinética , Bovinos/metabolismo , Indanos/farmacocinética , Sesquiterpenos/farmacocinética , Animais , Inativação Metabólica , Indanos/sangue , Indanos/urina , Pteridium/química , Rúmen/metabolismo , Sesquiterpenos/sangue , Sesquiterpenos/urina
3.
PLoS One ; 13(8): e0202255, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30102718

RESUMO

In tropical agriculture, the vigorously growing Bracken fern causes severe problems by invading pastures and out-competing the common pasture grasses. Due to infestation by that weed, pastures are abandoned after a few years, and as a fatal consequence, the biodiversity-rich tropical forest is progressively cleared for new grazing areas. Here we present a broad physiological comparison of the two plant species that are the main competitors on the pastures in the tropical Ecuadorian Andes, the planted forage grass Setaria sphacelata and the weed Bracken (Pteridium arachnoideum). With increasing elevation, the competitive power of Bracken increases as shown by satellite data of the study region. Using data obtained from field measurements, the annual biomass production of both plant species, as a measure of their competitive strength, was modeled over an elevational gradient from 1800 to 2800 m. The model shows that with increasing elevation, biomass production of the two species shifts in favor of Bracken which, above 1800 m, is capable of outgrowing the grass. In greenhouse experiments, the effects on plant growth of the presumed key variables of the elevational gradient, temperature and UV radiation, were separately analyzed. Low temperature, as well as UV irradiation, inhibited carbon uptake of the C4-grass more than that of the C3-plant Bracken. The less temperature-sensitive photosynthesis of Bracken and its effective protection from UV radiation contribute to the success of the weed on the highland pastures. In field samples of Bracken but not of Setaria, the content of flavonoids as UV-scavengers increased with the elevation. Combining modeling with measurements in greenhouse and field allowed to explain the invasive growth of a common weed in upland pastures. The performance of Setaria decreases with elevation due to suboptimal photosynthesis at lower temperatures and the inability to adapt its cellular UV screen.


Assuntos
Altitude , Espécies Introduzidas , Pteridium/crescimento & desenvolvimento , Setaria (Planta)/crescimento & desenvolvimento , Agricultura , Biomassa , Ácidos Cumáricos , Equador , Fotossíntese , Plantas Daninhas , Pteridium/química , Pteridium/efeitos da radiação , Setaria (Planta)/química , Setaria (Planta)/efeitos da radiação , Temperatura , Tiramina/análogos & derivados , Raios Ultravioleta
4.
Int J Biol Macromol ; 102: 599-604, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28412343

RESUMO

PAP1-A, a novel heteropolysaccharide with an average molecular mass of 1.35×105Da, was isolated from Pteridium aquilinum using a combination of chromatography by DEAE Sepharose Fast Flow and Sepharose 4B. The monosaccharide component of PAP1-A was L-rhamnose, L-arabinose, L-fucose, D-xylose, D-mannose, D-glucose and D-galactose in the molar ration of 1.82: 1.53: 1.42: 1.31: 5.24: 1: 12.35. The predicted structure of PAP1-A was established to be a complex polysaccharide with a main chain consisted of α-(1→4)-linked galactose partially substituted at O-6 position, with the (1→2)-linked xylose, (1→3)-linked arabinose, (1→3)-linked rhamnose, (1→3,6)-linked mannose, and (1→6)-linked mannose, as branches. Fucose, glucose, mannose, and rhamnose were located at the termini of the branches. The immunomodulatory activity assay showed that PAP1-A could significantly promote the RAW264.7 cells proliferation and induce the production of NO from RAW264.7 cells. Therefore, PAP1-A shows as a potent immunomodulator with potential applications in the medical and food industries.


Assuntos
Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Pteridium/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Hidrólise , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Metilação , Camundongos , Peso Molecular , Monossacarídeos/análise , Células RAW 264.7
5.
Chemosphere ; 165: 453-459, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27677121

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-1 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.


Assuntos
Carcinógenos/química , Indanos/química , Pteridium/química , Sesquiterpenos/química , Poluentes do Solo/química , Concentração de Íons de Hidrogênio , Hidrólise
6.
Food Chem Toxicol ; 97: 277-285, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27640346

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.


Assuntos
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 , Animais , Linfócitos T CD8-Positivos/imunologia , Carcinógenos/toxicidade , Feminino , Citometria de Fluxo , Humanos , Camundongos , Camundongos Transgênicos , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Dermatopatias/patologia , Neoplasias do Colo do Útero/patologia
7.
PLoS One ; 11(8): e0161670, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27552161

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.


Assuntos
Alelopatia , Pteridium/química , Pteridium/fisiologia , 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
8.
Phytochemistry ; 128: 82-94, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27177933

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.


Assuntos
Glicosídeos/isolamento & purificação , Indanos/isolamento & purificação , Pteridium/química , Rizoma/química , Sesquiterpenos/isolamento & purificação , Animais , Diabetes Mellitus/tratamento farmacológico , Glicosídeos/química , Indanos/química , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
9.
Molecules ; 21(5)2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27128893

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.


Assuntos
Água Potável/química , Indanos/análise , Pteridium/química , Sesquiterpenos/análise , Cromatografia Gasosa-Espectrometria de Massas , Irlanda , Poluentes Químicos da Água/análise
10.
Biochem Biophys Res Commun ; 473(2): 415-20, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-26970301

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.


Assuntos
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 , 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
11.
Med Hypotheses ; 88: 91-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26632203

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.


Assuntos
Carcinógenos/química , Infecções por Helicobacter/complicações , Helicobacter pylori , Pteridium/química , Neoplasias Gástricas/complicações , Neoplasias Gástricas/microbiologia , Animais , Sobrevivência Celular , Dieta , Mucosa Gástrica/imunologia , 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
12.
Parasitol Res ; 115(3): 997-1013, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26612497

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.


Assuntos
Antimaláricos/química , Inseticidas/química , Extratos Vegetais/química , Pteridium/química , Prata/toxicidade , Animais , Anopheles/efeitos dos fármacos , Anopheles/fisiologia , Antimaláricos/toxicidade , 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
13.
J Food Sci ; 80(12): C2717-24, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26551243

RESUMO

Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X-ray diffraction analysis revealed that bracken starch exhibited a typical C-type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch.


Assuntos
Pteridium/química , Rizoma/química , Amido/química , Amilopectina/química , Amilose/química , Cristalografia por Raios X , Digestão , Solanum tuberosum/química , Amido/isolamento & purificação , Viscosidade , Ceras/química , Difração de Raios X , Zea mays/química
14.
J Agric Food Chem ; 63(19): 4886-92, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25932502

RESUMO

Bracken fern (Pteridium aquilinum) is a worldwide plant containing toxic substances, which represent an important chemical hazard for animals, including humans. Ptaquiloside, 1, a norsesquiterpenoid glucoside, is the major carcinogen of bracken detected in the food chain, particularly in the milk from farm animals. To date, ptaquiloside has been shown in the milk of cows feeding on a diet containing bracken fern. This is the first study that shows the systematic detection of ptaquiloside, 1, and reports its direct quantitation in pooled raw milk of healthy sheep and goats grazing on bracken. Ptaquiloside, 1, was detected by a sensitive method based on the chemical conversion of ptaquiloside, 1, into bromopterosine, 4, following gas chromatography-mass spectrometry (GC-MS) analysis. The presence of ptaquiloside, 1, possibly carcinogenic to humans, in the milk of healthy animals is an unknown potential health risk, thus representing a harmful and potential global concern of food safety.


Assuntos
Cabras/metabolismo , Indanos/análise , Leite/química , Pteridium/metabolismo , Sesquiterpenos/análise , Ovinos/metabolismo , Animais , Carcinógenos/análise , Inocuidade dos Alimentos , Indanos/metabolismo , Pteridium/química , Sesquiterpenos/metabolismo
15.
J Environ Manage ; 151: 258-66, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25577704

RESUMO

Bracken ferns are some of the most widespread ferns in the World causing immense problems for land managers, foresters and rangers. Bracken is suspected of causing cancer in Humans due to its content of the carcinogen ptaquiloside. Ingestion of bracken, or food and drinking water contaminated with ptaquiloside may be the cause. The aim of this study was to monitor the content of ptaquiloside in 20 bracken stands from Britain to obtain a better understanding of the ptaquiloside dynamics and to evaluate the environmental implications of using different cutting regimes in bracken management. The ptaquiloside content in fronds ranged between 50 and 5790 µg/g corresponding to a ptaquiloside load in the standing biomass of up to 590 mg/m(2) in mature fronds. Ptaquiloside was also found in the underground rhizome system (11-657 µg/g) and in decaying litter (0.1-5.8 µg/g). The amount of ptaquiloside present in bracken stands at any given time is difficult to predict and did not show any correlations with edaphic growth factors. The content of ptaquiloside turned out to be higher in fronds emerging after cutting compared to uncut fronds. Environmental risk assessment and bracken management must therefore be based on actual and site specific determinations of the ptaquiloside content. Care must be taken to avoid leaching from cut ferns to aquifers and other recipients and appropriate precautionary measures must be taken to protect staff from exposure to bracken dust.


Assuntos
Carcinógenos/análise , Indanos/análise , Pteridium/química , Sesquiterpenos/análise , Solo/química , Conservação dos Recursos Naturais , Monitoramento Ambiental , Humanos , Indanos/química , Folhas de Planta/química , Rizoma/química , Medição de Risco , Escócia , Estações do Ano , Sesquiterpenos/química
16.
Environ Sci Pollut Res Int ; 22(1): 527-34, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25087499

RESUMO

Pteridium aquilinum is a ubiquitous species considered to be one of the plants most resistant to metals. This fern meets the demands for a good bioindicator to improve environmental control. Therefore, it was of interest to survey the accumulation of Cr and Ni in the rhizome and fronds of this species collected in Lower Silesia (SW Poland) of serpentinite rich in Cr and Ni and granite poor in these metals. Additionally, concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were measured in granite and serpentinite parent rocks, soils, and in P. aquilinum (rhizome and fronds). The experiment was carried out with rhizomes of ferns from both types of soils placed in pots supplemented with 50, 100, and 250 mg kg(-1) of Cr or Ni or both elements together. At a concentration of 250 mg kg(-1) of Cr, Ni, or Cr + Ni, fronds (from granite or serpentinite origin) contained significantly higher Cr and Ni concentrations when both metals were supplied together. In the same concentration of 250 mg kg(-1) of Cr, Ni, or Cr + Ni, rhizomes (from granite or serpentinite origin) contained significantly higher Cr and Ni concentrations when both metals were supplied separately. The explanation of metal differences in the joint accumulation of Cr and Ni on the rhizome or frond level needs further investigation. The lack of difference in Cr and Ni concentration in the rhizome and fronds between experimental P. aquilinum collected from granite and serpentinite soils may probably indicate that the phenotypic plasticity of this species is very important in the adaptation to extreme environments.


Assuntos
Adaptação Biológica , Cromo/análise , Níquel/análise , Pteridium/química , Asbestos Serpentinas/química , Cromo/metabolismo , Metais , Níquel/metabolismo , Polônia , Pteridium/metabolismo , Rizoma/química , Solo/química
17.
Sci Total Environ ; 496: 365-372, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25089695

RESUMO

The bracken fern Pteridium aquilinum (L.) Kuhn, one of the most common plant species on Earth, produces a wide range of secondary metabolites including the norsesquiterpene glucoside ptaquiloside (PTA). Several studies are present in literature about eco-toxicological aspects related to PTA, whereas results about the effect of growth conditions and soil properties on the production and mobility of PTA are sometimes conflicting and further investigations are needed. The aim of the present work is to investigate the occurrence and possible fate of PTA in soils showing different physical and chemical features, and collected in several areas of the South of Italy. The PTA content was determined in both soil and fern samples by GC-MS; both the extraction protocol and recovery were previously tested through incubation studies. Soils samples were also characterized from the physical and chemical points of view in order to correlate the possible influence of soil parameters on PTA production and occurrence. PTA concentration in P. aquilinum fern seemed to be significantly affected by the availability of nutrients (mainly P) and soil pH. At the same time, PTA concentration in soil samples was always undetectable, independent of the PTA concentration in the corresponding Pteridium samples and pedo-climatic conditions. This seems to suggest the degradation of the PTA by indigenous soil microbial community, whereas incubation studies underlined a certain affinity of PTA for both organic colloids and clay/silt particles.


Assuntos
Monitoramento Ambiental , Indanos/análise , Pteridium/química , Sesquiterpenos/análise , Poluentes do Solo/análise , Solo/química , Itália
18.
Artigo em Inglês | MEDLINE | ID: mdl-24508676

RESUMO

Ptaquiloside (PTA) is a toxin from bracken fern (Pteridium sp.) with genotoxic effects. Hydrolysis of PTA leads to the non-toxic and aromatised indanone, pterosin B (PTB). Here we present a sensitive, fast, simple and direct method, using SPE cartridges to clean and pre-concentrate PTA and PTB in plasma, urine and milk followed by LC-MS quantification. The average recovery of PTA in plasma, urine, and milk was 71, 88 and 77%, respectively, whereas recovery of PTB was 75, 82 and 63%. The method LOQ for PTA and PTB in plasma was 1.2 and 3.7ngmL(-1), 52 and 33ngmL(-1) for undiluted urine and 5.8 and 5.3ngmL(-1) for milk. The method is repeatable within and between days, with RSD values lower than 15% (PTA) and 20% (PTB). When PTA and PTB spiked samples were stored at -18°C for 14 days both compounds remained stable. In contrast, the PTA concentration was reduced by 15% when PTA spiked plasma was left for 5h at room temperature before SPE clean-up, whereas PTB remained stable. The method is the first to allow simultaneous quantification of PTA and PTB in biological fluids in a relevant concentration range. After intravenous administration of 0.092mg PTA per kgbw in a heifer, the plasma concentration was more than 300ngmL(-1) PTA and declined to 9.8ngmL(-1) after 6h, PTB was determined after 10min at 50ngmL(-1.)


Assuntos
Indanos/análise , Leite/química , Pteridium/química , Sesquiterpenos/análise , Animais , Bovinos , Feminino , Indanos/química , Indanos/farmacocinética , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Sesquiterpenos/química , Sesquiterpenos/farmacocinética
19.
Phytother Res ; 28(6): 798-810, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24123573

RESUMO

Many species of seedless vascular plants-ferns and lycopods-have been used as food and folk medicine since ancient times. Some of them have become the focus of intensive research concerning their anticancer properties. Studies on the anticancer effect of crude extracts are being increasingly replaced by bioactivity-guided fractionation, as well as detailed assessment of the mechanism of action. Numerous compounds-especially flavonoids such as amentoflavone and protoapigenone, and also simpler phenolic compounds, steroids, alkaloids and terpenoids-were isolated and found to be cytotoxic, particularly pro-apoptotic, or to induce cell cycle arrest in cancer cell lines in vitro. In in vivo experiments, some fern-derived compounds inhibited tumour growth with little toxicity. On the other hand, many ferns-not only the well-known Bracken (Pteridium)-may pose a significant hazard to human health due to the fact that they contain carcinogenic sesquiterpenoids and their analogues. The objective of this review is to summarise the recent state of research on the anticancer properties of ferns and lycopods, with a focus on their characteristic bioactive constituents. The carcinogenic hazard posed by ferns is also mentioned.


Assuntos
Antineoplásicos Fitogênicos/química , Carcinógenos/química , Gleiquênias/química , Lycopodiaceae/química , Animais , Linhagem Celular , Flavonoides/química , Humanos , Fenóis/química , Pteridium/química , Terpenos/química
20.
Environ Toxicol ; 29(7): 763-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-22859263

RESUMO

Bracken (Pteridium aquilinum) is a carcinogenic plant whose main toxin, ptaquiloside, causes cancer in farm and laboratory animals. Ptaquiloside contaminates underground waters as well as meat and milk from bracken-grazing animals and is a suspected human carcinogen. A better understanding of the underlying mechanisms of carcinogenesis can be achieved by studying the early stages of this process. Unfortunately, most research on ptaquiloside has focused on the late, malignant, lesions, so the early changes of ptaquiloside-induced carcinogenesis remain largely unknown. This study aims to characterize early-stage ptaquiloside-induced urinary bladder lesions both morphologically and immunohistochemically. 12 male CD-1 mice were administered 0.5 mg ptaquiloside intraperitoneally, weekly, for 15 weeks, followed by 15 weeks without treatment. 12 control animals were administered saline. Bladders were tested immunohistochemically for antibodies against a cell proliferation marker (Ki-67), and two cell adhesion markers (E-cadherin and ß-catenin). Two exposed animals died during the work. Six ptaquiloside-exposed mice developed low-grade and two developed high grade urothelial dysplasia. No lesions were detected on control animals. Significantly, increased (p < 0.05) Ki-67 labeling indices were found on dysplastic urothelium from ptaquiloside-exposed mice, compared with controls. No differences were found concerning E-cadherin and ß-catenin expression. Early-stage ptaquiloside-induced urothelial lesions show increased cell proliferation but there is no evidence for reduced intercellular adhesiveness, though this may be a later event in tumor progression.


Assuntos
Caderinas/metabolismo , Proliferação de Células/efeitos dos fármacos , Indanos/toxicidade , Pteridium/química , Sesquiterpenos/toxicidade , Urotélio/efeitos dos fármacos , beta Catenina/metabolismo , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/patologia , Urotélio/patologia
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