Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
Mais filtros










Filtros aplicados
Base de dados
Intervalo de ano de publicação
1.
Mol Phylogenet Evol ; 137: 44-63, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30999036

RESUMO

With 145 species, Turnera is the largest genus of Turneraceae (Malpighiales). Despite several morphotaxonomic and cytogenetic studies, our knowledge about the phylogenetic relationships in Turnera remains mainly based on morphological data. Here, we reconstruct the most comprehensive phylogeny of Turnera with molecular data to understand the morphological evolution within this group and to assess its circumscription and infrageneric classification. We analyzed two nuclear and six plastid markers and 112 taxa, including species and infraspecific taxa, 97 from Turnera, covering the 11 series of the genus. Bayesian inference, maximum parsimony and maximum likelihood analyses show that Turnera, as traditionally circumscribed, is not monophyletic. The genus is divided into two well-supported independent clades; one of them is sister to the genus Piriqueta and is here segregated as the new genus Oxossia. According to our reconstructions, Turnera probably evolved from an ancestor without extrafloral nectaries and with solitary, homostylous flowers with yellow petals. The emergences of extrafloral nectaries and distyly, both common in extant taxa, played an important role in the diversification of the genus. An updated infrageneric classification reflecting the relationships within Turnera is now possible based on morphological synapomorphies and is here designed for further studies.


Assuntos
Classificação , Filogenia , Turnera/anatomia & histologia , Turnera/genética , Teorema de Bayes , Biodiversidade , Sequência Consenso , Inflorescência/genética , Tricomas/genética , Turnera/classificação
2.
Molecules ; 24(5)2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30823394

RESUMO

In our continuing search for new cytotoxic agents, we assayed extracts, fractions, and pure compounds from damiana (Turnera diffusa) against multiple myeloma (NCI-H929, U266, and MM1S) cell lines. After a first liquid-liquid solvent extraction, the ethyl acetate layer of an acetone (70%) crude extract was identified as the most active fraction. Further separation of the active fraction led to the isolation of naringenin (1), three apigenin coumaroyl glucosides 2⁻4, and five flavone aglycones 5⁻9. Naringenin (1) and apigenin 7-O-(4″-O-p-E-coumaroyl)-glucoside (4) showed significant cytotoxic effects against the tested myeloma cell lines. Additionally, we established a validated ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method for the quantification of the isolated components in the herb and in traditional preparations of T. diffusa.


Assuntos
Antineoplásicos Fitogênicos , Citotoxinas , Mieloma Múltiplo/tratamento farmacológico , Extratos Vegetais , Turnera/classificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Citotoxinas/química , Citotoxinas/farmacologia , Humanos , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Espectrometria de Massas por Ionização por Electrospray
3.
J Med Food ; 22(4): 384-392, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30900937

RESUMO

Cardiovascular and thromboembolic disturbances are the main causes of disease-related deaths worldwide. Regardless of the etiological factors involved in thrombus formation, coagulation is mainly activated by thrombin, one of the most important blood clotting molecules. Thus, this study evaluated the Turnera subulata leaf crude extract, its ethyl acetate fraction effect on the coagulation cascade, and its possible side effects. Their phytocomposition indicated polyphenols, mainly flavonol-3-O-glycosylate and a flavone glycoside, without in vitro and in vivo toxicity. Regarding their potential anticoagulants, results displayed partial thromboplastin and prothrombin time activation, and Xa and IIa, and thrombin inhibition by heparin II cofactor, indicating significant anticoagulant activity, suggesting direct and indirect thrombin inhibition as the main mechanism of action. Therefore, T. subulata leaf active compounds exhibit therapeutic potential required to develop phytotherapeutic formulations to assist conventional anticoagulants in clinical treatments.


Assuntos
Anticoagulantes/administração & dosagem , Extratos Vegetais/administração & dosagem , Trombina/antagonistas & inibidores , Tromboembolia/tratamento farmacológico , Turnera/química , Animais , Anticoagulantes/química , Coagulação Sanguínea/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Masculino , Extratos Vegetais/química , Folhas de Planta/química , Tempo de Protrombina , Ratos , Ratos Wistar , Tromboembolia/sangue
4.
Molecules ; 24(4)2019 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-30813423

RESUMO

The investigation of the constituents that were isolated from Turnera diffusa (damiana) for their inhibitory activities against recombinant human monoamine oxidases (MAO-A and MAO-B) in vitro identified acacetin 7-methyl ether as a potent selective inhibitor of MAO-B (IC50 = 198 nM). Acacetin 7-methyl ether (also known as 5-hydroxy-4', 7-dimethoxyflavone) is a naturally occurring flavone that is present in many plants and vegetables. Acacetin 7-methyl ether was four-fold less potent as an inhibitor of MAO-B when compared to acacetin (IC50 = 50 nM). However, acacetin 7-methyl ether was >500-fold selective against MAO-B over MAO-A as compared to only two-fold selectivity shown by acacetin. Even though the IC50 for inhibition of MAO-B by acacetin 7-methyl ether was ~four-fold higher than that of the standard drug deprenyl (i.e., SelegilineTM or ZelaparTM, a selective MAO-B inhibitor), acacetin 7-methyl ether's selectivity for MAO-B over MAO-A inhibition was greater than that of deprenyl (>500- vs. 450-fold). The binding of acacetin 7-methyl ether to MAO-B was reversible and time-independent, as revealed by enzyme-inhibitor complex equilibrium dialysis assays. The investigation on the enzyme inhibition-kinetics analysis with varying concentrations of acacetin 7-methyl ether and the substrate (kynuramine) suggested a competitive mechanism of inhibition of MAO-B by acacetin 7-methyl ether with Ki value of 45 nM. The docking scores and binding-free energies of acacetin 7-methyl ether to the X-ray crystal structures of MAO-A and MAO-B confirmed the selectivity of binding of this molecule to MAO-B over MAO-A. In addition, molecular dynamics results also revealed that acacetin 7-methyl ether formed a stable and strong complex with MAO-B. The selective inhibition of MAO-B suggests further investigations on acacetin 7-methyl as a potential new drug lead for the treatment of neurodegenerative disorders, including Parkinson's disease.


Assuntos
Flavonas/química , Inibidores da Monoaminoxidase/química , Monoaminoxidase/metabolismo , Extratos Vegetais/química , Turnera/química , Sítios de Ligação , Flavonas/isolamento & purificação , Humanos , Concentração Inibidora 50 , Cinética , Éteres Metílicos/química , Éteres Metílicos/isolamento & purificação , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Extratos Vegetais/isolamento & purificação , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato
5.
J Ethnopharmacol ; 236: 50-62, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-30818006

RESUMO

AIMS: To explore the antidepressant- and anxiolytic-like effects of an aqueous extract of Turnera diffusa Willd (Turneraceae) and to explore its possible toxic side effects on behavior, target organ function, and spermatic quality. MATERIALS AND METHODS: Acute effects of a T. diffusa aqueous extract were evaluated in adult male mice with the plus-maze, forced swimming and open field tests to identify the possible anxiolytic, antidepressant and stimulant effects of this extract. Effects of T. diffusa aqueous extract were further investigated through two approaches. a) Male and female adult mice receiving a 28-day treatment were evaluated in a neurobehavioral test battery; later, changes in their biochemical parameters and in target organ morphology were analyzed. b) In young adult (16-weeks old) and mature (46-weeks old) males, spermatic quality and testes morphology during a complete spermatogenesis cycle were analyzed after a 35-day treatment. RESULTS: T. diffusa aqueous extract induced remarkable anxiolytic- and antidepressant-like effects without affecting locomotor activity. This extract did not elicit behavioral signs of neural side effects, a sex-dependent reduction in body weight gain was produced without affecting functional parameters or the morphology of target organs. The highest dose improved cellular turnover in the testes of mature mice. CONCLUSION: T. diffusa aqueous extract induced a clear anxiolytic-like effect, and for the first time, we reported an antidepressant effect. Clinical potential or even intake of T. diffusa in the context of traditional medicine can be supported by its efficacy to positively modulate behavior and its safety for a wide range of doses.


Assuntos
Ansiolíticos/farmacologia , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Turnera/química , Animais , Ansiolíticos/isolamento & purificação , Ansiolíticos/toxicidade , Antidepressivos/isolamento & purificação , Antidepressivos/toxicidade , Relação Dose-Resposta a Droga , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos dos fármacos , Especificidade de Órgãos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Teste de Desempenho do Rota-Rod , Espermatogênese/efeitos dos fármacos , Natação , Testículo/efeitos dos fármacos , Testículo/patologia
6.
Environ Toxicol ; 34(3): 330-339, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30578656

RESUMO

Oxidative stress and increased production of reactive oxygen species have been implicated in pesticides and heavy metals toxicity. The objective of this study was to investigate the efficacy of Turnera diffusa Willd (damiana) on counteracting fenitrothion (FNT) and/or potassium dichromate (CrVI)-induced testicular toxicity and oxidative injury in rats. FNT and/or CrVI intoxicated animals revealed a significant increase in thiobarbituric acid reactive substances and hydrogen peroxide levels. While, reduced glutathione and protein content, as well as antioxidant enzymes, phosphatases, and aminotransferases activities, were significantly decreased. In addition, significant changes in testosterone and follicle-stimulating hormone levels were detected. Furthermore, histological and immunohistochemical alterations were observed in rat testes and this supported the observed biochemical changes. On the other hand, rats treated with damiana alone decreased lipid peroxidation and increased most of the examined parameters. Moreover, damiana pretreatment to FNT and/or CrVI-intoxicated rats showed significant improvement in lipid peroxidation, enzyme activities, and hormones as compared with their respective treated groups. Conclusively, rats treated with both FNT and/or CrVI showed pronounced hazardous effect especially in their combination group in addition, Turnera diffusa had a potential protective role against FNT and/or CrVI induced testicular toxicity.


Assuntos
Cromo/toxicidade , Fenitrotion/toxicidade , Extratos Vegetais/administração & dosagem , Substâncias Protetoras/administração & dosagem , Testículo/efeitos dos fármacos , Turnera/química , Animais , Antioxidantes/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Dicromato de Potássio/toxicidade , Ratos , Ratos Wistar , Testículo/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
7.
Neotrop Entomol ; 47(6): 750-756, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29982978

RESUMO

Symbiosis between plants and ants include examples in which the plant provides shelter and/or food for ants that, in turn, act in the defense or in the dispersion of seeds from the host plant. Although traditionally referred as mutualistic, the results of these interactions may vary with the ecological context in which patterns are involved. A range of species have facultative association with Turnera subulata (Turneraceae). Here, using behavioral bioassays, we investigated the effects of the most frequent ant species associated with T. subulata (Brachymyrmex sp.1, Camponotus blandus (Smith), Dorymyrmex sp.1, Crematogaster obscurata Emery, and Solenopsis invicta Buren) in the dispersion of plant host seeds and in the number of seedlings around the associated ant nests. We also evaluated the effects of these ant species in the germination of T. subulata seeds, in the consumption of elaiosome, and in the attractiveness to elaiosome odor. Our results showed that the ant species associated with T. subulata presented variation in the attraction by the odor and in the rate of consumption of the elaiosomes. However, none of the ant species studied contributed significantly to the increase of seed germination and seedling growth. Our results suggest that the consumption of the elaiosome by ant species is not a determinant factor to the success of germination of T. subulata. However, such species could contribute indirectly to seed germination by carrying seeds to sites more fertile to germination. In general, our results help to elucidate the results of ecological interactions involving ants and plants.


Assuntos
Formigas/fisiologia , Germinação , Dispersão de Sementes , Turnera/fisiologia , Animais , Simbiose
8.
PLoS One ; 13(6): e0199764, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29949639

RESUMO

Variation in partner species and frequency of interaction between species pairs are potential drivers of the net outcome of generalized mutualisms. In ant-plant mutualisms, the quality of defence provided by ants is related to ant aggressiveness. Hence, we hypothesize that the performance of plants bearing extrafloral nectaries will be higher when they interact more frequently with more aggressive ant species. We estimated ant aggressiveness in the field by observing their behaviour towards soil baits. Afterwards, we observed the frequency with which individuals from these ant species visited plants through an entire reproductive cycle. We measured the production and persistence of plants reproductive structures through this period and the total seed production. Increasing in the interaction frequency with highly aggressive ants reduced the number of floral buds and seeds produced. Increased visitation frequency by less aggressive ants increased the number of floral buds and seeds per branch. The inverse relationship between ant aggressiveness and seed production may be influenced by the costs imposed by different mutualistic partners. Thus, frequent interaction with highly aggressive ants may lead to a higher accumulation of costs through time, resulting in a negative net outcome for the plants. Our results bring new evidence highlighting the importance to incorporate temporal aspects in the study of mutualistic interactions. We suggests that the quality of mutualistic partners must be understood as a function of its per-interaction benefit and their cumulative costs to their partner over time, what puts in check our current classification regarding partner quality in mutualistic systems.


Assuntos
Formigas/fisiologia , Néctar de Plantas/fisiologia , Simbiose , Turnera/fisiologia , Agressão , Animais , Flores/fisiologia , Frutas/fisiologia , Reprodução , Sementes/fisiologia
9.
J Med Food ; 21(4): 372-379, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29437539

RESUMO

Medicinal plants have been used in primary healthcare since the earliest days of humankind. Turnera subulata and Spondias mombin × Spondias tuberosa are widely used in the Brazilian Northeast to treat several diseases. The aim of this study was to evaluate the genotoxic effects of the leaf extracts of these species by the somatic mutation and recombination test in the somatic cells of Drosophila melanogaster wings. The experiments were performed using standard and high-bioactivation cross and three concentrations of the test substance [aqueous extract (AET and AES) at 5.0, 10.0, and 20.0 mg/mL and ethanolic extract (EET and EES) and ethyl acetate fraction (EAFT and EAFS) at 0.625, 1.25, and 2.5 mg/mL]. Results indicated that the extracts and fractions induced spontaneous frequencies of mutant spots in both D. melanogaster crosses. Nevertheless, the highest concentrations of the tested plant chemical agents were responsible for the statistically significant genotypic effect. T. subulata and S. mombin × S. tuberosa displayed genotoxic effect under the experimental conditions. The results from this study are crucial as they indicated the deleterious and side effects, considering the indiscriminate use of the extracts of these plants for disease treatment.


Assuntos
Anacardiaceae/toxicidade , Mutagênicos/toxicidade , Mutação , Extratos Vegetais/toxicidade , Turnera/toxicidade , Animais , Brasil , Drosophila melanogaster/efeitos dos fármacos , Testes de Mutagenicidade , Folhas de Planta , Plantas Medicinais
10.
J Plant Res ; 131(1): 77-89, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28831641

RESUMO

Triploids can play an important role in polyploid evolution. However, their frequent sterility is an obstacle for the origin and establishment of neotetraploids. Here we analyzed the microsporogenesis of triploids (x = 7) and the crossability among cytotypes of Turnera sidoides, aiming to test the impact of triploids on the origin and demographic establishment of tetraploids in natural populations. Triploids of T. sidoides exhibit irregular meiotic behavior. The high frequency of monovalents and of trivalents with non-convergent orientations results in unbalanced and/or non-viable male gametes. In spite of abnormalities in chromosome pairing and unbalanced chromosome segregation, triploids are not completely sterile and yielded up to 67% of viable pollen. Triploids that originated by the fusion of 2n × n gametes of the same taxon showed more regular meiotic behavior and higher fertility than triploids from the contact zone of diploids and tetraploids or triploids of hybrid origin. The reproductive isolation of T. sidoides cytotypes of different ploidy level is not strict and the 'triploid block' may be overcome occasionally. Triploids of T. sidoides produce diploid and triploid progeny suggesting that new generations of polyploids could originate from crosses between triploids or from backcrosses with diploids. The capability of T. sidoides to multiply asexually by rhizomes, would enhance the likelihood that a low frequency of neopolyploids can be originated and maintained in natural populations of T. sidoides.


Assuntos
Pólen/crescimento & desenvolvimento , Triploidia , Turnera/genética , Argentina , Evolução Molecular , Dinâmica Populacional , Reprodução , Turnera/crescimento & desenvolvimento
11.
Nat Prod Res ; 32(23): 2840-2843, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28948849

RESUMO

The antioxidant effects of water-ethanol extract (WEE) from Turnera diffusa (damiana) in kidney mitochondria from experimental streptozotocin-induced diabetes mellitus (STZ-DM) rats was evaluated. STZ-DM rats were orally treated during three and five weeks. After experimental periods, kidney mitochondria were isolated and malondialdehyde (MDA), nitric oxide (NO•) and protein nitrosylation levels were measured. Also, blood glucose (BG) and body weight (BW) were recorded. Damiana significantly reduced the MDA and NO• levels in kidney mitochondria, although no changes in protein nitrosylation were observed and it did not have the potential to reverse the hyperglycaemia. In conclusion, WEE of T. diffusa have antioxidant properties that may prevent damage induced by mitochondrial oxidative stress in kidneys of STZ-DM rats.


Assuntos
Antioxidantes/farmacologia , Mitocôndrias/efeitos dos fármacos , Extratos Vegetais/farmacologia , Turnera/química , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Rim/metabolismo , Rim/ultraestrutura , Masculino , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Estreptozocina/farmacologia
12.
Food Chem Toxicol ; 106(Pt A): 466-476, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28606766

RESUMO

One of the most promising approaches to confront the complexity of central nervous system disorders are new multi-target directed ligands (MTDLs). Five medicinal species (Cereus grandiflorus (L.) Mill., Hyssopus officinalis L., Acorus calamus L., Silybum marianum L. Gaertn. and Turnera diffusa Willd. Ex Schult), selected for their ethnopharmacological relevance, were object for in vitro screening. The aqueous extract of T. diffusa revealed the strongest neuroactive potential, inhibiting monoamine oxidase-A (IC50 = 129.80 ± 11.97 µg/mL), and acetyl- and butyrylcholinesterase (IC25 = 0.352 ± 0.011 and 0.370 ± 0.036 mg/mL, respectively). Its phenolic profile was established for the first time by HPLC-DAD-ESI/MSn. Twenty-six out of thirty-seven compounds were newly identified in this species. The pre-treatment with this flavonoid-rich extract promoted a rightward shift of the glutamate concentration neuronal cell (SH-SY5Y) death response curve. Furthermore, it significantly reduced the early phase formation of intracellular reactive species after glutamate and t-BHP exposure, suggesting that neuroprotection in SH-SY5Y cells was, in part, mediated by antioxidant mechanisms.


Assuntos
Doenças do Sistema Nervoso Central/tratamento farmacológico , Ácido Glutâmico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Turnera/química , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Doenças do Sistema Nervoso Central/metabolismo , Ácido Glutâmico/toxicidade , Humanos , Espectrometria de Massas , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Espécies Reativas de Oxigênio/metabolismo
13.
Molecules ; 22(4)2017 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-28397755

RESUMO

Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. Turnera diffusa (damiana) is a shrub that grows throughout Mexico and is traditionally used for many illnesses including diabetes. Although a large number of plant metabolites are known, there are no reports indicating which of these are responsible for this activity, and this identification was the objective of the present work. Through bioassay-guided fractionation of a methanolic extract obtained from the aerial part of T. diffusa, teuhetenone A was isolated and identified as the main metabolite responsible for the plant's hypoglycemic activity. Alpha-glucosidase inhibitory activity and cytotoxicity of this metabolite were determined. Hypoglycemic and antidiabetic activities were evaluated in a murine model of diabetes in vivo, by monitoring glucose levels for six hours and comparing them with levels after administering various controls. Teuhetenone A was not cytotoxic at the tested concentrations, and did not show inhibitory activity in the glucosidase test, and the in vivo assays showed a gradual reduction in glucose levels in normoglycemic and diabetic mice. Considering these results, we suggest that teuhetenone A has potential as an antidiabetic compound, which could be further submitted to preclinical assays.


Assuntos
Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Turnera/química , Animais , Glicemia/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/isolamento & purificação , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Extratos Vegetais/isolamento & purificação , alfa-Glucosidases/metabolismo
14.
Vet Parasitol ; 236: 121-127, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28288755

RESUMO

Helminth infections represent a serious problem for the production of small ruminants that is currently aggravated by resistance to anthelmintic products and has induced a search for control alternatives, such as natural products. In this study, extracts of Turnera ulmifolia L. (leaves and roots), Parkia platycephala Benth. (leaves and seeds) and Dimorphandra gardneriana Tul. (leaves and bark), which have been cited in ethnoveterinary studies and selected naturally by goats in the cerrado (Brazilian savanna), were tested in vitro against Haemonchus contortus. Hydroacetonic (ACT) and hydroalcoholic (ETH) extracts were evaluated using an Egg Hatching Assay (EHA), a Larval Exsheathment Inhibition Assay (LEIA) and a Larval Development Assay (LDA). A second set of incubations was performed using polyvinylpolypyrrolidone (PVPP) to determine the influence of polyphenols on the anthelmintic effects of EHA and LEIA. Data from each extract were used to calculate inhibition concentrations (IC50). All tested extracts showed activity against at least one life stage of H. contortus. The use of PVPP revealed that the tannins are not the only extracts of secondary metabolites responsible for the anthelmintic effects. The results showed clear in vitro anthelmintic activities against H. contortus at different stages and indicated the potential use of these species as a promising alternative approach to control helminthic infections of small ruminants.


Assuntos
Anti-Helmínticos/farmacologia , Fabaceae/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Turnera/química , Animais , Brasil , Pradaria , Casca de Planta/química , Folhas de Planta/química , Raízes de Plantas/química , Sementes/química
15.
Plant Biol (Stuttg) ; 19(2): 101-107, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27770594

RESUMO

The evolution of monomorphisms from heterostylous ancestors has been related to the presence of homostyly and the loss of self-incompatibility, allowing the occurrence of selfing, which could be advantageous under pollinator limitation. However, flowers of some monomorphic species show herkogamy, attraction and rewarding traits that presumably favour cross-pollination and/or a mixed mating system. This study evaluated the contributions of pollinators, breeding system and floral traits to the reproduction of Turnera velutina, a herkogamous monomorphic species. Floral visitors and frequency of visits were recorded, controlled hand cross-pollinations were conducted under greenhouse and natural conditions, and individual variation in floral traits was characterised to determine their contribution to seed production. Apis mellifera was the most frequent floral visitor. Flowers presented approach herkogamy, high variation in nectar features, and a positive correlation of floral length with nectar volume and sugar concentration. Seed production did not differ between manual self- and cross-pollinations, controls or open cross-pollinations, but autonomous self-pollination produced, on average, 82.74% fewer seeds than the other forms, irrespective of the level of herkogamy. Differences in seed production among autonomous self-pollination and other treatments showed that T. velutina flowers depend on insect pollination for reproduction, and that approach herkogamy drastically reduced seed production in the absence of pollen vectors. The lack of differences in seed production from manual cross- and self-pollinations suggests the possible presence of a mixed mating system in the studied population. Overall, this species was possibly derived from a distylous ancestor but appears fully capable of outcrossing despite being monomorphic.


Assuntos
Polinização , Turnera/fisiologia , Animais , Abelhas/fisiologia , Evolução Biológica , Cruzamento , Cruzamentos Genéticos , Flores/genética , Flores/fisiologia , Insetos/fisiologia , Fenótipo , Néctar de Plantas/genética , Néctar de Plantas/fisiologia , Pólen/genética , Pólen/fisiologia , Poliploidia , Reprodução , Sementes/genética , Sementes/fisiologia , Autofertilização , Autoincompatibilidade em Angiospermas , Turnera/genética
16.
Nat Commun ; 7: 13026, 2016 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-27713409

RESUMO

Expansion of the cytochrome P450 gene family is often proposed to have a critical role in the evolution of metabolic complexity, in particular in microorganisms, insects and plants. However, the molecular mechanisms underlying the evolution of this complexity are poorly understood. Here we describe the evolutionary history of a plant P450 retrogene, which emerged and underwent fixation in the common ancestor of Brassicales, before undergoing tandem duplication in the ancestor of Brassicaceae. Duplication leads first to gain of dual functions in one of the copies. Both sister genes are retained through subsequent speciation but eventually return to a single copy in two of three diverging lineages. In the lineage in which both copies are maintained, the ancestral functions are split between paralogs and a novel function arises in the copy under relaxed selection. Our work illustrates how retrotransposition and gene duplication can favour the emergence of novel metabolic functions.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Sistema Enzimático do Citocromo P-450/genética , Evolução Molecular , Fabaceae/genética , Genes de Plantas/genética , Turnera/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Fabaceae/metabolismo , Duplicação Gênica/genética , Variação Genética/genética , Retroelementos/genética , Turnera/metabolismo
17.
Am Nat ; 188(1): 38-51, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27322120

RESUMO

Many plants attract insect pollinators with floral nectar (FN) and ant "bodyguards" with extrafloral nectar (EFN). If nectar production is costly or physiologically linked across glands, investment in one mutualism may trade off with investment in the other. We confirmed that changes in FN and EFN availability alter pollination and ant defense mutualisms in a field population of Turnera ulmifolia. Plants with additional FN tended to produce more seeds, while plants with reduced EFN production experienced less florivory. We then mimicked the consumptive effects of mutualists by removing FN or EFN daily for 50 days in a full factorial design using three Turnera species (T. joelii, T. subulata, and T. ulmifolia) in a glasshouse experiment. For T. ulmifolia and T. subulata, but not T. joelii, removing either nectar reduced production of the other, showing for the first time that EFN and FN production can trade off. In T. subulata, increased investment in FN decreased seed set, suggesting that nectar production can have direct fitness costs. Through the linked expression of EFN and FN, floral visitors may negatively affect biotic defense, and extrafloral nectary visitors may negatively affect pollination.


Assuntos
Formigas , Néctar de Plantas , Polinização , Turnera/fisiologia , Animais , Recompensa
18.
Einstein (Sao Paulo) ; 14(1): 56-63, 2016.
Artigo em Inglês, Português | MEDLINE | ID: mdl-27074236

RESUMO

OBJECTIVE: To evaluate the phytochemical composition of hydroethanolic extracts from powdered aerial parts of Turnera diffusa Willd (Turneraceae; T. diffusa), as well as its toxicity in astrocytes. METHODS: Chemical analyses of hydroethanolic extract from powdered aerial parts ofT. diffusa were carried out using HPLC-DAD-ESI-MS/MS.In vitro assays using astrocytes culture were performed to evaluate cell death. RESULTS: Flavone-C, O-diglycosides, such as, luteolin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside, apigenin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside and apigenin-7-O-6"-p-coumaroylglucoside were the main compounds found in this hydroethanolic extract. Concentration time-effect demonstrated the toxicity of this extract at a concentration of 1,000µg/mL in astrocyte culture, after 6 and 24 hours of incubation. CONCLUSION: In phytochemical analyses, important antioxidants (mainly flavonoids) were observed. T. diffusa extracts presented cytotoxic effect in high concentrations, leading to increased cell death in astrocyte culture.


Assuntos
Antioxidantes/química , Astrócitos/efeitos dos fármacos , Extratos Vegetais/química , Turnera/química , Animais , Astrócitos/química , Morte Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão/métodos , Flavonas/análise , Flavonas/toxicidade , Extratos Vegetais/toxicidade , Ratos , Espectrometria de Massas por Ionização por Electrospray/métodos
19.
Genome ; 59(2): 127-36, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26794024

RESUMO

Turnera sidoides is an autopolyploid complex of obligate outcrossing perennial herbs. It includes five subspecies and five morphotypes in which diploid to octoploid cytotypes were found. Based on phenetic analyses of the complex and karyotype data of polyploid cytotypes, it has been hypothesized that morphological and chromosome differentiation of T. sidoides occurred at the diploid level. To test this hypothesis, we present the first detailed chromosome analysis of diploid populations of three subspecies and four morphotypes. CMA(+)/DAPI(-) bands were restricted to secondary constrictions (except in the andino morphotype) and varied in number and position among taxa. By contrast, DAPI staining was uniform in all the materials investigated. The number and position of 45S rDNA loci were coincident with the CMA(+)/DAPI(-) bands associated with secondary constrictions. Only one pair of 5S rDNA loci was detected in all the taxa (except in subsp. holosericea), but its position was variable. The identified chromosome markers varied among the three subspecies analyzed, but they were more conserved among the morphotypes of subsp. pinnatifida. Cluster analysis of these chromosome markers supports the current taxonomic arrangement of diploids and demonstrates that structural chromosome changes would have led or accompanied the initial differentiation of T. sidoides at the diploid level.


Assuntos
Turnera/genética , Cromossomos de Plantas , DNA de Plantas/genética , DNA Ribossômico/genética , Diploide , Especiação Genética , Hibridização in Situ Fluorescente , Cariótipo , Filogenia
20.
Artigo em Inglês | MEDLINE | ID: mdl-26473510

RESUMO

OBJECTIVE: To describe the effects of suspected synthetic cannabinoid (SC) toxicosis and the response to intravenous lipid emulsion (ILE) therapy in a dog. CASE SUMMARY: A 2-year-8-month-old male Boxer dog was evaluated at an emergency hospital for progressive ataxia and inappropriate mentation. The initial physical examination identified marked hypothermia (32.7°C [90.9°F]), intermittent sinus bradycardia (60/min), stuporous mentation with intermittent aggression, and severe ataxia. Neurologic status deteriorated to comatose mentation within 2 hours of presentation. The initial diagnostic evaluation (eg, CBC, serum biochemistry profile, venous blood gas, and electrolyte determination) revealed a respiratory acidosis and thrombocytopenia. The owner reported that the dog was exposed to an SC containing Damiana leaf, Marshmallow leaf, and Athaea leaves. Initial treatment included IV fluids and supplemental oxygen. Mechanical ventilation was provided due to hypoventilation and periods of apnea. Intravenous lipid emulsion therapy was administered as a bolus (1.5 mL/kg) and continued as a continuous rate infusion (0.5 mL/kg/h) for a total of 6 hours. The dog became rousable and was weaned from mechanical ventilation approximately 15 hours following presentation. The dog was eating and walking with no ataxia, had a normal mentation at approximately 33 hours following presentation, and was discharged home at that time. Communication with the owners 5 days following discharge revealed that the dog was apparently normal. NEW OR UNIQUE INFORMATION PROVIDED: Based on this case and other reports in the literature regarding human exposures, SC ingestion may result in more severe clinical signs than marijuana ingestion in dogs. Significant clinical intervention may be necessary. Intravenous lipid emulsion treatment may be beneficial due to the lipophilicity of SC.


Assuntos
Canabinoides/toxicidade , Doenças do Cão/induzido quimicamente , Althaea , Animais , Cães , Hidratação , Masculino , Oxigênio , Respiração Artificial , Turnera
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA