Base de dados : MEDLINE Pesquisa : B01.650.940.800.575.912.250.198.500.050.500 [Categoria DeCS] Referências encontradas : 103 [refinar] Mostrando: 1 .. 10   no formato [Detalhado]

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[PMID]: 28401290 [Au] Autor: Yu K; D'Odorico P; Li W; He Y [Ad] Endereço: Department of Environmental Sciences, University of Virginia, Charlottesville, VA, 22904, USA. ky9hc@virginia.edu. [Ti] Título: Effects of competition on induction of crassulacean acid metabolism in a facultative CAM plant. [So] Source: Oecologia;184(2):351-361, 2017 Jun. [Is] ISSN: 1432-1939 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Abiotic drivers of environmental stress have been found to induce CAM expression (nocturnal carboxylation) in facultative CAM species such as Mesembryanthemum crystallinum. The role played by biotic factors such as competition with non-CAM species in affecting CAM expression, however, remains largely understudied. This research investigated the effects of salt and water conditions on the competition between M. crystallinum and the C grass Bromus mollis with which it is found to coexist in California's coastal grasslands. We also investigated the extent to which CAM expression in M. crystallinum was affected by the intensity of the competition with B. mollis. We found that M. crystallinum had a competitive advantage over B. mollis in drought and saline conditions, while B. mollis exerted strong competitive effects on M. crystallinum in access to light and soil nutrients in high water conditions. This strong competitive effect even outweighed the favorable effects of salt or water additions in increasing the biomass and productivity of M. crystallinum in mixture. Regardless of salt conditions, M. crystallinum did not switch to CAM photosynthesis in response to this strong competitive effect from B. mollis. Disturbance (i.e., grass cutting) reduced the competitive pressure by B. mollis and allowed for CAM expression in M. crystallinum when it was grown mixed with B. mollis. We suggest that moderate competition with other functional groups can enhance CAM expression in M. crystallinum, thereby affecting its plasticity and ability to cope with biological stress. [Mh] Termos MeSH primário: Mesembryanthemum/metabolismo Fotossíntese [Mh] Termos MeSH secundário: California Plantas Cloreto de Sódio Estresse Fisiológico [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 451W47IQ8X (Sodium Chloride) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171012 [Lr] Data última revisão: 171012 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170413 [St] Status: MEDLINE [do] DOI: 10.1007/s00442-017-3868-6

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[PMID]: 27810674 [Au] Autor: Percey WJ; Shabala L; Wu Q; Su N; Breadmore MC; Guijt RM; Bose J; Shabala S [Ad] Endereço: School of Land and Food, University of Tasmania, Hobart, Tas 7001, Australia. [Ti] Título: Potassium retention in leaf mesophyll as an element of salinity tissue tolerance in halophytes. [So] Source: Plant Physiol Biochem;109:346-354, 2016 Dec. [Is] ISSN: 1873-2690 [Cp] País de publicação: France [La] Idioma: eng [Ab] Resumo: Soil salinity remains a major threat to global food security, and the progress in crop breeding for salinity stress tolerance may be achieved only by pyramiding key traits mediating plant adaptive responses to high amounts of dissolved salts in the rhizosphere. This task may be facilitated by studying natural variation in salinity tolerance among plant species and, specifically, exploring mechanisms of salinity tolerance in halophytes. The aim of this work was to establish the causal link between mesophyll ion transport activity and plant salt tolerance in a range of evolutionary contrasting halophyte and glycophyte species. Plants were grown under saline conditions in a glasshouse, followed by assessing their growth and photosynthetic performance. In a parallel set of experiments, net K and H transport across leaf mesophyll and their modulation by light were studied in control and salt-treated mesophyll segments using vibrating non-invasive ion selective microelectrode (the MIFE) technique. The reported results show that mesophyll cells in glycophyte species loses 2-6 fold more K compared with their halophyte counterparts. This decline was reflected in a reduced maximum photochemical efficiency of photosystem II, chlorophyll content and growth observed in the glasshouse experiments. In addition to reduced K efflux, the more tolerant species also exhibited reduced H efflux, which is interpreted as an energy-saving strategy allowing more resources to be redirected towards plant growth. It is concluded that the ability of mesophyll to retain K without a need to activate plasma membrane H -ATPase is an essential component of salinity tolerance in halophytes and halophytic crop plants. [Mh] Termos MeSH primário: Potássio/metabolismo Plantas Tolerantes a Sal/metabolismo [Mh] Termos MeSH secundário: Aizoaceae/metabolismo Beta vulgaris/metabolismo Chenopodium quinoa/metabolismo Clorofila/metabolismo Mesembryanthemum/metabolismo Células do Mesofilo/metabolismo Fotossíntese Folhas de Planta/metabolismo Salinidade Tolerância a Sal/fisiologia Especificidade da Espécie Vicia faba/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 1406-65-1 (Chlorophyll); RWP5GA015D (Potassium) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 170410 [Lr] Data última revisão: 170410 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161105 [St] Status: MEDLINE

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[PMID]: 27806052 [Au] Autor: Guiducci L; Razghandi K; Bertinetti L; Turcaud S; Rüggeberg M; Weaver JC; Fratzl P; Burgert I; Dunlop JW [Ad] Endereço: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany. [Ti] Título: Honeycomb Actuators Inspired by the Unfolding of Ice Plant Seed Capsules. [So] Source: PLoS One;11(11):e0163506, 2016. [Is] ISSN: 1932-6203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Plant hydro-actuated systems provide a rich source of inspiration for designing autonomously morphing devices. One such example, the pentagonal ice plant seed capsule, achieves complex mechanical actuation which is critically dependent on its hierarchical organization. The functional core of this actuation system involves the controlled expansion of a highly swellable cellulosic layer, which is surrounded by a non-swellable honeycomb framework. In this work, we extract the design principles behind the unfolding of the ice plant seed capsules, and use two different approaches to develop autonomously deforming honeycomb devices as a proof of concept. By combining swelling experiments with analytical and finite element modelling, we elucidate the role of each design parameter on the actuation of the prototypes. Through these approaches, we demonstrate potential pathways to design/develop/construct autonomously morphing systems by tailoring and amplifying the initial material's response to external stimuli through simple geometric design of the system at two different length scales. [Mh] Termos MeSH primário: Mesembryanthemum Sementes [Mh] Termos MeSH secundário: Algoritmos Fenômenos Mecânicos Mesembryanthemum/fisiologia Modelos Teóricos Polímeros Sementes/anatomia & histologia Sementes/química Sementes/fisiologia [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Polymers) [Em] Mês de entrada: 1706 [Cu] Atualização por classe: 170626 [Lr] Data última revisão: 170626 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161103 [St] Status: MEDLINE [do] DOI: 10.1371/journal.pone.0163506

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[PMID]: 27553978 [Au] Autor: Carpenter JM; Jourdan MK; Fountain EM; Ali Z; Abe N; Khan IA; Sufka KJ [Ad] Endereço: National Center for Natural Products Research, University of Mississippi, University, MS 38677, USA. [Ti] Título: The effects of Sceletium tortuosum (L.) N.E. Br. extract fraction in the chick anxiety-depression model. [So] Source: J Ethnopharmacol;193:329-332, 2016 Dec 04. [Is] ISSN: 1872-7573 [Cp] País de publicação: Ireland [La] Idioma: eng [Ab] Resumo: ETHNOPHARMACOLOGICAL RELEVANCE: Sceletium tortuosum (L.) N.E. Br. has been reported to elevate mood, reduce anxiety and stress and alleviate pain. AIM OF STUDY: This study sought to examine the effects of an S. tortuosum alkaloid enriched fraction in the chick anxiety-depression model, a model that shows high predictive validity as a pharmacological screening assay. MATERIAL AND METHODS: Socially-raised male Silver Laced Wyandotte chicks (4-6 days old) were given IP vehicle, imipramine (10mg/kg), or S. tortuosum fraction (10, 20, 30mg/kg in Exp. 1 or 50, 75, 100mg/kg in Exp. 2) 15min prior to a 60min isolation test period in which distress vocalizations (DVoc) were continuously recorded. RESULTS: Vehicle chicks displayed high DVoc rates in the anxiety phase (first 3min). DVoc rates declined about 50% (i.e., behavioral despair) in the depression phase (30-60min). S. tortuosum fraction at 75 and 100mg/kg decreased DVoc rates during the anxiety phase indicative of an anxiolytic effect. Imipramine, but not S. tortuosum groups, increased DVoc rates in the depression phase indicative of an antidepressant effect. CONCLUSIONS: The findings suggest that an alkaloid enriched S. tortuosum fraction may benefit some forms of stress-related disorders. [Mh] Termos MeSH primário: Antidepressivos/uso terapêutico Ansiedade/tratamento farmacológico Depressão/tratamento farmacológico Modelos Animais de Doenças Mesembryanthemum/química Extratos Vegetais/uso terapêutico [Mh] Termos MeSH secundário: Animais Galinhas Imipramina/uso terapêutico Masculino [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antidepressive Agents); 0 (Plant Extracts); OGG85SX4E4 (Imipramine) [Em] Mês de entrada: 1705 [Cu] Atualização por classe: 170714 [Lr] Data última revisão: 170714 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160825 [St] Status: MEDLINE

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[PMID]: 27368070 [Au] Autor: Surówka E; Dziurka M; Kocurek M; Goraj S; Rapacz M; Miszalski Z [Ad] Endereço: The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland. Electronic address: ewa.surowka@gmail.com. [Ti] Título: Effects of exogenously applied hydrogen peroxide on antioxidant and osmoprotectant profiles and the C3-CAM shift in the halophyte Mesembryanthemum crystallinum L. [So] Source: J Plant Physiol;200:102-10, 2016 Aug 01. [Is] ISSN: 1618-1328 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Exogenously applied H2O2 (50, 100 and 200mM) to Mesembryanthemum crystallinum root medium induced a transition from C3 to Crassulacean Acid Metabolism (CAM), as evaluated by diurnal malate (Δmal) fluctuations. A very high concentration of H2O2 (400mM) reduced Δmal below the value measured in control plants. An increase of malate content during the night in 400mM H2O2-treated plants might suggest that malate decarboxylation is crucial for CAM functioning. We conclude that malate plays a dual role: i) a protective and signaling function before CAM expression, and ii) a storage form of CO2 in plants performing CAM. A slight stimulation of photosystem II (PSII) photochemistry and net photosynthesis observed during the C3-CAM shift indicated that neither photoinhibition nor reduction of the photosynthetic rate were prerequisites for CAM. Moreover, CAM induction corresponded to a decrease of catalase activity. In CAM-performing plants, α-tocopherol, polyamines (putrescine and spermidine) and proline showed daily alterations and the content of α-tocopherol and polyamines was lower at the end of the day. In contrast, the proline concentration correlated with the applied H2O2 concentration and was higher at the end of the day in treated plants. The dynamic changes of antioxidant and osmolyte levels suggest their active role in preventing oxidative damage, stress acclimation mechanisms and involvement in metabolic regulation and/or signal transduction cascades. [Mh] Termos MeSH primário: Antioxidantes/metabolismo Carbono/metabolismo Ácidos Carboxílicos/metabolismo Peróxido de Hidrogênio/farmacologia Mesembryanthemum/fisiologia Osmose/efeitos dos fármacos Plantas Tolerantes a Sal/fisiologia [Mh] Termos MeSH secundário: Catalase/metabolismo Gases/metabolismo Mesembryanthemum/efeitos dos fármacos Mesembryanthemum/enzimologia Fotossíntese/efeitos dos fármacos Complexo de Proteína do Fotossistema II/metabolismo Folhas de Planta/efeitos dos fármacos Folhas de Planta/metabolismo Poliaminas/metabolismo Prolina/metabolismo Plantas Tolerantes a Sal/efeitos dos fármacos Estresse Fisiológico/efeitos dos fármacos alfa-Tocoferol/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antioxidants); 0 (Carboxylic Acids); 0 (Gases); 0 (Photosystem II Protein Complex); 0 (Polyamines); 7440-44-0 (Carbon); 9DLQ4CIU6V (Proline); BBX060AN9V (Hydrogen Peroxide); EC 1.11.1.6 (Catalase); H4N855PNZ1 (alpha-Tocopherol) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 170410 [Lr] Data última revisão: 170410 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160702 [St] Status: MEDLINE

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[PMID]: 27160145 [Au] Autor: Barkla BJ; Vera-Estrella R; Raymond C [Ad] Endereço: Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia. bronwyn.barkla@scu.edu.au. [Ti] Título: Single-cell-type quantitative proteomic and ionomic analysis of epidermal bladder cells from the halophyte model plant Mesembryanthemum crystallinum to identify salt-responsive proteins. [So] Source: BMC Plant Biol;16(1):110, 2016 May 10. [Is] ISSN: 1471-2229 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: BACKGROUND: Epidermal bladder cells (EBC) are large single-celled, specialized, and modified trichomes found on the aerial parts of the halophyte Mesembryanthemum crystallinum. Recent development of a simple but high throughput technique to extract the contents from these cells has provided an opportunity to conduct detailed single-cell-type analyses of their molecular characteristics at high resolution to gain insight into the role of these cells in the salt tolerance of the plant. RESULTS: In this study, we carry out large-scale complementary quantitative proteomic studies using both a label (DIGE) and label-free (GeLC-MS) approach to identify salt-responsive proteins in the EBC extract. Additionally we perform an ionomics analysis (ICP-MS) to follow changes in the amounts of 27 different elements. Using these methods, we were able to identify 54 proteins and nine elements that showed statistically significant changes in the EBC from salt-treated plants. GO enrichment analysis identified a large number of transport proteins but also proteins involved in photosynthesis, primary metabolism and Crassulacean acid metabolism (CAM). Validation of results by western blot, confocal microscopy and enzyme analysis helped to strengthen findings and further our understanding into the role of these specialized cells. As expected EBC accumulated large quantities of sodium, however, the most abundant element was chloride suggesting the sequestration of this ion into the EBC vacuole is just as important for salt tolerance. CONCLUSIONS: This single-cell type omics approach shows that epidermal bladder cells of M. crystallinum are metabolically active modified trichomes, with primary metabolism supporting cell growth, ion accumulation, compatible solute synthesis and CAM. Data are available via ProteomeXchange with identifier PXD004045. [Mh] Termos MeSH primário: Mesembryanthemum/metabolismo Proteínas de Plantas/metabolismo Plantas Tolerantes a Sal/metabolismo Cloreto de Sódio/metabolismo [Mh] Termos MeSH secundário: Regulação da Expressão Gênica de Plantas Espectrometria de Massas Mesembryanthemum/química Mesembryanthemum/genética Proteínas de Plantas/química Proteínas de Plantas/genética Proteômica Plantas Tolerantes a Sal/química Plantas Tolerantes a Sal/genética [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Plant Proteins); 451W47IQ8X (Sodium Chloride) [Em] Mês de entrada: 1708 [Cu] Atualização por classe: 170816 [Lr] Data última revisão: 170816 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160511 [St] Status: MEDLINE [do] DOI: 10.1186/s12870-016-0797-1

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[PMID]: 27091507 [Au] Autor: Kuzniak E; Kornas A; Kazmierczak A; Rozpadek P; Nosek M; Kocurek M; Zellnig G; Müller M; Miszalski Z [Ad] Endereço: Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lódz, Poland. [Ti] Título: Photosynthesis-related characteristics of the midrib and the interveinal lamina in leaves of the C3-CAM intermediate plant Mesembryanthemum crystallinum. [So] Source: Ann Bot;117(7):1141-51, 2016 Jun. [Is] ISSN: 1095-8290 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: BACKGROUND AND AIMS: Leaf veins are usually encircled by specialized bundle sheath cells. In C4 plants, they play an important role in CO2 assimilation, and the photosynthetic activity is compartmentalized between the mesophyll and the bundle sheath. In C3 and CAM (Crassulacean acid metabolism) plants, the photosynthetic activity is generally attributed to the leaf mesophyll cells, and the vascular parenchymal cells are rarely considered for their role in photosynthesis. Recent studies demonstrate that enzymes required for C4 photosynthesis are also active in the veins of C3 plants, and their vascular system contains photosynthetically competent parenchyma cells. However, our understanding of photosynthesis in veins of C3 and CAM plants still remains insufficient. Here spatial analysis of photosynthesis-related properties were applied to the midrib and the interveinal lamina cells in leaves of Mesembryanthemum crystallinum, a C3-CAM intermediate plant. METHODS: The midrib anatomy as well as chloroplast structure and chlorophyll fluorescence, diurnal gas exchange profiles, the immunoblot patterns of PEPC (phosphoenolpyruvate carboxylase) and RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase), H2O2 localization and antioxidant enzyme activities were compared in the midrib and in the interveinal mesophyll cells in leaves of C3 and CAM plants. KEY RESULTS: Leaf midribs were structurally competent to perform photosynthesis in C3 and CAM plants. The midrib chloroplasts resembled those in the bundle sheath cells of C4 plants and were characterized by limited photosynthetic activity. CONCLUSIONS: The metabolic roles of midrib chloroplasts differ in C3 and CAM plants. It is suggested that in leaves of C3 plants the midrib chloroplasts could be involved in the supply of CO2 for carboxylation, and in CAM plants they could provide malate to different metabolic processes and mediate H2O2 signalling. [Mh] Termos MeSH primário: Mesembryanthemum/fisiologia Fotossíntese/fisiologia Folhas de Planta/anatomia & histologia Folhas de Planta/fisiologia Proteínas de Plantas/metabolismo [Mh] Termos MeSH secundário: Antioxidantes/metabolismo Ascorbato Peroxidases/metabolismo Dióxido de Carbono/metabolismo Catalase/metabolismo Parede Celular/química Parede Celular/metabolismo Clorofila/química Clorofila/metabolismo Cloroplastos/ultraestrutura Glucanos/metabolismo Peróxido de Hidrogênio/metabolismo Lignina/metabolismo Fosfoenolpiruvato Carboxilase/metabolismo Folhas de Planta/citologia Ribulose-Bifosfato Carboxilase/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antioxidants); 0 (Glucans); 0 (Plant Proteins); 1406-65-1 (Chlorophyll); 142M471B3J (Carbon Dioxide); 9005-53-2 (Lignin); 9064-51-1 (callose); BBX060AN9V (Hydrogen Peroxide); EC 1.11.1.11 (Ascorbate Peroxidases); EC 1.11.1.6 (Catalase); EC 4.1.1.31 (Phosphoenolpyruvate Carboxylase); EC 4.1.1.39 (Ribulose-Bisphosphate Carboxylase) [Em] Mês de entrada: 1707 [Cu] Atualização por classe: 170724 [Lr] Data última revisão: 170724 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160420 [St] Status: MEDLINE [do] DOI: 10.1093/aob/mcw049

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[PMID]: 26745003 [Au] Autor: Amari T; Lutts S; Taamali M; Lucchini G; Sacchi GA; Abdelly C; Ghnaya T [Ad] Endereço: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia. Electronic address: taoufik.amari@gmail.com. [Ti] Título: Implication of citrate, malate and histidine in the accumulation and transport of nickel in Mesembryanthemum crystallinum and Brassica juncea. [So] Source: Ecotoxicol Environ Saf;126:122-128, 2016 Apr. [Is] ISSN: 1090-2414 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Citrate, malate and histidine have been involved in many processes including metal tolerance and accumulation in plants. These molecules have been frequently reported to be the potential nickel chelators, which most likely facilitate metal transport through xylem. In this context, we assess here, the relationship between organics acids and histidine content and nickel accumulation in Mesembryanthemum crystallinum and Brassica juncea grown in hydroponic media added with 25, 50 and 100 µM NiCl2. Results showed that M. crystallinum is relatively more tolerant to Ni toxicity than B. juncea. For both species, xylem transport rate of Ni increased with increasing Ni supply. A positive correlation was established between nickel and citrate concentrations in the xylem sap. In the shoot of B. juncea, citric and malic acids concentrations were significantly higher than in the shoot of M. crystallinum. Also, the shoots and roots of B. juncea accumulated much more histidine. In contrast, a higher root citrate concentration was observed in M. crystallinum. These findings suggest a specific involvement of malic and citric acid in Ni translocation and accumulation in M. crystallinum and B. juncea. The high citrate and histidine accumulation especially at 100µM NiCl2, in the roots of M. crystallinum might be among the important factors associated with the tolerance of this halophyte to toxic Ni levels. [Mh] Termos MeSH primário: Ácido Cítrico/metabolismo Histidina/metabolismo Malatos/metabolismo Mesembryanthemum/metabolismo Mostardeira/metabolismo Níquel/farmacocinética [Mh] Termos MeSH secundário: Transporte Biológico/fisiologia Raízes de Plantas/metabolismo Brotos de Planta/metabolismo Plantas Tolerantes a Sal Xilema [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Malates); 2968PHW8QP (Citric Acid); 4QD397987E (Histidine); 7OV03QG267 (Nickel); 817L1N4CKP (malic acid) [Em] Mês de entrada: 1610 [Cu] Atualização por classe: 170826 [Lr] Data última revisão: 170826 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160109 [St] Status: MEDLINE

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[PMID]: 26615766 [Au] Autor: Coetzee DD; López V; Smith C [Ad] Endereço: Department of Physiological Sciences, Science Faculty, Stellenbosch University, Stellenbosch, South Africa. [Ti] Título: High-mesembrine Sceletium extract (Trimesemine™) is a monoamine releasing agent, rather than only a selective serotonin reuptake inhibitor. [So] Source: J Ethnopharmacol;177:111-6, 2016 Jan 11. [Is] ISSN: 1872-7573 [Cp] País de publicação: Ireland [La] Idioma: eng [Ab] Resumo: ETHNOPHARMACOLOGICAL RELEVANCE: Extracts from and alkaloids contained in plants in the genus Sceletium have been reported to inhibit ligand binding to serotonin transporter. From this, the conclusion was made that Sceletium products act as selective serotonin-reuptake inhibitors. However, other mechanisms which may similarly result in the anxiolytic or anti-depressant effect ascribed to Sceletium, such as monoamine release, have not been investigated. AIMS OF THE STUDY: The current study investigated simultaneously and at two consecutive time points, the effect of high-mesembrine Sceletium extract on both monoamine release and serotonin reuptake into both human astrocytes and mouse hippocampal neurons, as well as potential inhibitory effects on relevant enzyme activities. MATERIALS AND METHODS: Human astrocytes and mouse hippocampal cells were treated with citalopram or Sceletium extract for 15 and 30min, after which protein expression levels of serotonin transporter (SERT) and vesicular monoamine transporter-2 (VAMT-2) was assessed using fluorescent immunocytochemistry and digital image analysis. Efficacy of inhibition of acetylcholinesterase (AChE) and monoamine oxidate-A (MAO-A) activity were assessed using the Ellman and Olsen methods (and appropriate controls) respectively. RESULTS: We report the first investigation of mechanism of action of Sceletium extract in the context of serotonin transport, release and reuptake in a cellular model. Cell viability was not affected by Sceletium treatment. High-mesembrine Sceletium extract down-regulated SERT expression similarly to citalopram. In addition, VMAT-2 was upregulated significantly in response to Sceletium treatment. The extract showed only relatively mild inhibition of AChE and MAO-A. CONCLUSIONS: We conclude that the serotonin reuptake inhibition activity ascribed to the Sceletium plant, is a secondary function to the monoamine-releasing activity of high-mesembrine Sceletium extract (Trimesemine(TM)). [Mh] Termos MeSH primário: Monoaminas Biogênicas/metabolismo Alcaloides de Indol/farmacologia Mesembryanthemum/química Extratos Vegetais/farmacologia Inibidores da Captação de Serotonina/farmacologia [Mh] Termos MeSH secundário: Animais Astrócitos/efeitos dos fármacos Sobrevivência Celular/efeitos dos fármacos Relação Dose-Resposta a Droga Alcaloides de Indol/química Camundongos Monoaminoxidase/metabolismo Inibidores da Monoaminoxidase Neurônios/efeitos dos fármacos Extratos Vegetais/química [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Biogenic Monoamines); 0 (Indole Alkaloids); 0 (Monoamine Oxidase Inhibitors); 0 (Plant Extracts); 0 (Serotonin Uptake Inhibitors); 86E2ZU4ETY (mesembrine); EC 1.4.3.4 (Monoamine Oxidase) [Em] Mês de entrada: 1609 [Cu] Atualização por classe: 160101 [Lr] Data última revisão: 160101 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151201 [St] Status: MEDLINE

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[PMID]: 26608706 [Au] Autor: Swart AC; Smith C [Ad] Endereço: Dept Biochemistry, Stellenbosch University, South Africa. Electronic address: acswart@sun.ac.za. [Ti] Título: Modulation of glucocorticoid, mineralocorticoid and androgen production in H295 cells by Trimesemine™, a mesembrine-rich Sceletium extract. [So] Source: J Ethnopharmacol;177:35-45, 2016 Jan 11. [Is] ISSN: 1872-7573 [Cp] País de publicação: Ireland [La] Idioma: eng [Ab] Resumo: ETHNOPHARMACOLOGICAL RELEVANCE: Stress-related illnesses rate among the most prevalent non-fatal diseases globally. With the global trend for consumer bias towards natural medicine, the Sceletium plant has become more prominent in the field of natural products. Although potentially useful effects of Sceletium tortuosum on the central nervous system have been reported, limited data is available on effects of the plant in the peripheral compartment. AIM OF THE STUDY: The current study aimed to elucidate the effect(s) of a Sceletium extract (TRI) rich in mesembrine (1% of plant extract w/w), on adrenal steroid biosynthesis. MATERIALS AND METHODS: Steroidogenesis was assessed basally and in response to stimuli (forskolin, angiotensin II, KCl), in human adrenocortical carcinoma cells (H295R). Steroid hormone levels were assessed using UPLC-MS/MS. UPLC-MS analyses of TRI identified major alkaloids Δ7-mesembrenone, mesembrenone and mesembrine. RESULTS: Highest dose TRI treatment (1 mg/ml, 34.5 µM mesembrine) increased pregnenolone and decreased 16-hydroxyprogesterone levels (both P<0.00001) in forskolin-stimulated conditions only, suggesting CYP17 enzyme inhibition. This led to significant inhibition of forskolin-associated increases in cortisol levels at the highest dose (P<0.001) and basal cortisol levels across all doses (P<0.0001). Independently of forskolin, TRI inhibited androstenedione and testosterone production across all doses (both P<0.00001), suggesting inhibition of 3ßHSD and 17ßHSD respectively. TRI decreased both the angiotensin II- (P<0.05) and forskolin-induced (P<0.0001) increases in aldosterone production. CONCLUSIONS: Our data suggest potentially beneficial effects of TRI in the context of stress and hypertension. These should be further investigated in a whole organism model, while the effects on the androgenic pathway should also be further elucidated. [Mh] Termos MeSH primário: Androgênios/metabolismo Glucocorticoides/metabolismo Alcaloides de Indol/farmacologia Mesembryanthemum/química Mineralocorticoides/metabolismo Extratos Vegetais/farmacologia [Mh] Termos MeSH secundário: Linhagem Celular Tumoral Regulação da Expressão Gênica/efeitos dos fármacos Regulação da Expressão Gênica/fisiologia Seres Humanos Alcaloides de Indol/química Extratos Vegetais/química Plantas Medicinais [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Androgens); 0 (Glucocorticoids); 0 (Indole Alkaloids); 0 (Mineralocorticoids); 0 (Plant Extracts); 86E2ZU4ETY (mesembrine) [Em] Mês de entrada: 1609 [Cu] Atualização por classe: 160101 [Lr] Data última revisão: 160101 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151127 [St] Status: MEDLINE

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