27 results on '"de Costa F"'
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2. Observations of a solar flare and filament eruption in Lyman α and X-rays
- Author
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Rubio de Costa, F., Fletcher, L., Labrosse, N., and Zuccarello, F.
- Subjects
QC ,QB - Abstract
Context: Lα is a strong chromospheric emission line, which has been relatively rarely observed in flares. The Transition Region and Coronal Explorer (TRACE) has a broad “Lyman α” channel centered at 1216 Å used primarily at the beginning of the mission. A small number of flares were observed in this channel.\ud \ud Aims: We aim to characterise the appearance and behaviour of a flare and filament ejection which occurred on 8th September 1999 and was observed by TRACE in Lα, as well as by the Yohkoh Soft and Hard X-ray telescopes. We explore the flare energetics and its spatial and temporal evolution. We have in mind the fact that the Lα line is a target for the Extreme Ultraviolet Imaging telescope (EUI) which has been selected for the Solar Orbiter mission, as well as the LYOT telescope on the proposed SMESE mission.\ud \ud Methods: We use imaging data from the TRACE 1216 Å, 1600 Å and 171 Å channels, and the Yohkoh hard and soft X-ray telescopes. A correction is applied to the TRACE data to obtain a better estimate of the pure Lα signature. The Lα power is obtained from a knowledge of the TRACE response function, and the flare electron energy budget is estimated by interpreting Yohkoh/HXT emission in the context of the collisional thick target model.\ud \ud Results: We find that the Lα flare is characterised by strong, compact footpoints (smaller than the UV ribbons) which correlate well with HXR footpoints. The Lα power radiated by the flare footpoints can be estimated, and is found to be on the order of 1026 erg s-1 at the peak. This is less than 10% of the power inferred for the electrons which generate the co-spatial HXR emission, and can thus readily be provided by them. The early stages of the filament eruption that accompany the flare are also visible, and show a diffuse, roughly circular spreading sheet-like morphology, with embedded denser blobs.\ud \ud Conclusions: On the basis of this observation, we conclude that flare and filament observations in the Lα line with the planned EUI and LYOT telescopes will provide valuable insight into solar flare evolution and energetics, especially when accompanied by HXR imaging and spectroscopy.
- Published
- 2009
3. Quillaja brasiliensis saponins are less toxic than Quil A and have similar properties when used as an adjuvant for a viral antigen preparation
- Author
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Silveira, F., primary, Cibulski, S.P., additional, Varela, A.P., additional, Marqués, J.M., additional, Chabalgoity, A., additional, de Costa, F., additional, Yendo, A.C.A., additional, Gosmann, G., additional, Roehe, P.M., additional, Fernández, C., additional, and Ferreira, F., additional
- Published
- 2011
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4. Immunoadjuvant and Anti-Inflammatory Plant Saponins: Characteristics and Biotechnological Approaches Towards Sustainable Production
- Author
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de Costa, F., primary, C.A. Yendo, A., additional, D. Fleck, J., additional, Gosmann, G., additional, and G. Fett-Neto, A., additional
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- 2011
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5. Asymmetric Baxter phase in the symmetric Ashkin-Teller model
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de Costa, F. A., primary, de Oliveira, M. J., additional, and Salinas, S. R., additional
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- 1987
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6. The mediating role of electronic word-of-mouth in the relationship between CSR initiative and consumer satisfaction.
- Author
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Hua X, Mohd Hasan NA, De Costa F, and Qiao W
- Abstract
The importance of CSR in today's business environment cannot be ignored, especially more and more enterprises realize that when consumers perceive CSR, it will affect consumer behavior and then affect corporate efficiency and reputation. With the widespread application of social media, corporate social responsibility behaviors are easy to be participated and discussed by consumers on the Internet, forming electronic word-of-mouth. Therefore, this paper discusses the influence of electronic word-of-mouth between CSR and consumer satisfaction, taking China's largest Internet enterprise Tencent and its consumers and users as the research object. The overall purpose of this study is to explore the mediating role of electronic word-of-mouth in CSR and consumer satisfaction. This study uses Stimulus-Organism-Response (SOR) theory as the theoretical framework to explain the relationship between CSR initiatives, eWOM and consumer satisfaction. Using the quantitative method of questionnaire survey, taking China's enterprise Tencent as an example, a total of 490 valid questionnaires from Tencent WeChat users from four different levels of cities were received. The PLS-SEM model was used to deeply study the impact of CSR on consumer satisfaction and electronic word-of-mouth. The study found that philanthropic responsibility has a significant impact on consumer satisfaction, but environmental responsibility has no significant impact on satisfaction. At the same time, electronic word-of-mouth plays a key mediating role between the dimension of charitable responsibility and consumer satisfaction, but there is no mediating relationship between the dimension of environmental responsibility and consumer satisfaction. This study is beneficial to other enterprises in the formulation and planning of social responsibility, helps enterprises better understand consumer demands under different CSR dimensions, and provides a useful reference for the formulation of more accurate CSR strategies., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)
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- 2024
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7. Attenuation of Oxidative Stress by Cannabinoids and Cannabis Extracts in Differentiated Neuronal Cells.
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Raja A, Ahmadi S, de Costa F, Li N, and Kerman K
- Abstract
In this proof-of-concept study, the antioxidant activity of phytocannabinoids, namely cannabidiol (CBD) and Δ9- tetrahydrocannabinol (THC), were investigated using an in vitro system of differentiated human neuronal SY-SH5Y cells. The oxidative stress was induced by hydrogen peroxide, as reactive oxygen species (ROS). Alzheimer's disease (AD)-like pathological conditions were mimicked in vitro by treating the differentiated neuronal cells with amyloid-β
1 - 42 (Aβ1 - 42 ) in the presence of Cu(II). We showed that THC had a high potency to combat oxidative stress in both in vitro models, while CBD did not show a remarkable antioxidant activity. The cannabis extracts also exhibited a significant antioxidant activity, which depended on the ratio of the THC and CBD. However, our results did not suggest any antagonist effect of the CBD on the antioxidant activity of THC. The effect of cannabis extracts on the cell viability of differentiated human neuronal SY-SH5Y cells was also investigated, which emphasized the differences between the bioactivity of cannabis extracts due to their composition. Our preliminary results demonstrated that cannabis extracts and phytocannabinoids have a promising potential as antioxidants, which can be further investigated to develop novel pharmaceuticals targeting oxidative stress therapy., Competing Interests: The authors declare no conflict of interest.- Published
- 2020
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8. Probing the antioxidant activity of Δ 9 -tetrahydrocannabinol and cannabidiol in Cannabis sativa extracts.
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Hacke ACM, Lima D, de Costa F, Deshmukh K, Li N, Chow AM, Marques JA, Pereira RP, and Kerman K
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- Cannabidiol analysis, Dronabinol analysis, Electrochemical Techniques methods, Free Radical Scavengers analysis, Plant Extracts analysis, Cannabidiol chemistry, Cannabis chemistry, Dronabinol chemistry, Free Radical Scavengers chemistry, Plant Extracts chemistry
- Abstract
Herein, we report the antioxidant activity of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) in pure and mixed solutions at different ratios, as well as of six different Cannabis sativa extracts containing various proportions of CBD and THC by using spectrophotometric (reducing power assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), hypochlorous acid (HOCl) scavenging assays) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry). The isolated cannabinoids, the different stoichiometric ratios of CBD and THC, and the natural extracts proved to have remarkable antioxidant properties in all the methods employed in this work. The antioxidant activity of CBD and THC was compared against that of the well-defined antioxidants such as ascorbic acid (AA), resveratrol (Resv) and (-)-epigallocatechin-3-gallate (EGCG). Clear evidence of the synergistic and antagonistic effects between CBD and THC regarding to their antioxidant activities was observed. Moreover, a good correlation was obtained between the optical and electrochemical methods, which proved that the reported experimental procedures can easily be adapted to determine the antioxidant activity of extracts from various Cannabis sativa species and related compounds.
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- 2019
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9. Specialized Plant Metabolism Characteristics and Impact on Target Molecule Biotechnological Production.
- Author
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Matsuura HN, Malik S, de Costa F, Yousefzadi M, Mirjalili MH, Arroo R, Bhambra AS, Strnad M, Bonfill M, and Fett-Neto AG
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- Artemisinins isolation & purification, Artemisinins metabolism, Axenic Culture, Berberine isolation & purification, Berberine metabolism, Biological Products isolation & purification, Cell Culture Techniques, Naphthoquinones isolation & purification, Naphthoquinones metabolism, Paclitaxel biosynthesis, Paclitaxel isolation & purification, Phytochemicals isolation & purification, Plant Cells chemistry, Plants chemistry, Plants genetics, Secondary Metabolism, Tissue Culture Techniques, Biological Products metabolism, Biotechnology methods, Metabolic Engineering methods, Phytochemicals biosynthesis, Plant Cells metabolism, Plants metabolism
- Abstract
Plant secondary metabolism evolved in the context of highly organized and differentiated cells and tissues, featuring massive chemical complexity operating under tight environmental, developmental and genetic control. Biotechnological demand for natural products has been continuously increasing because of their significant value and new applications, mainly as pharmaceuticals. Aseptic production systems of plant secondary metabolites have improved considerably, constituting an attractive tool for increased, stable and large-scale supply of valuable molecules. Surprisingly, to date, only a few examples including taxol, shikonin, berberine and artemisinin have emerged as success cases of commercial production using this strategy. The present review focuses on the main characteristics of plant specialized metabolism and their implications for current strategies used to produce secondary compounds in axenic cultivation systems. The search for consonance between plant secondary metabolism unique features and various in vitro culture systems, including cell, tissue, organ, and engineered cultures, as well as heterologous expression in microbial platforms, is discussed. Data to date strongly suggest that attaining full potential of these biotechnology production strategies requires being able to take advantage of plant specialized metabolism singularities for improved target molecule yields and for bypassing inherent difficulties in its rational manipulation.
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- 2018
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10. Corrigendum: Reference Genes for qPCR Analysis in Resin-Tapped Adult Slash Pine As a Tool to Address the Molecular Basis of Commercial Resinosis.
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de Lima JC, de Costa F, Füller TN, Rodrigues-Corrêa KCDS, Kerber MR, Lima MS, Fett JP, and Fett-Neto AG
- Abstract
[This corrects the article on p. 849 in vol. 7, PMID: 27379135.].
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- 2018
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11. Leaf saponins of Quillaja brasiliensis enhance long-term specific immune responses and promote dose-sparing effect in BVDV experimental vaccines.
- Author
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Cibulski S, Rivera-Patron M, Suárez N, Pirez M, Rossi S, Yendo AC, de Costa F, Gosmann G, Fett-Neto A, Roehe PM, and Silveira F
- Subjects
- Adjuvants, Immunologic administration & dosage, Adjuvants, Immunologic adverse effects, Adjuvants, Immunologic chemistry, Animals, Antibodies, Viral blood, Antibodies, Viral immunology, Antibody Formation immunology, Bovine Virus Diarrhea-Mucosal Disease prevention & control, CD8-Positive T-Lymphocytes, Cattle, Diarrhea Virus 1, Bovine Viral immunology, Dose-Response Relationship, Immunologic, Immunoglobulin G blood, Immunoglobulin G immunology, Mice, Plant Extracts administration & dosage, Plant Extracts adverse effects, Plant Extracts chemistry, Plant Leaves chemistry, Quillaja Saponins administration & dosage, Quillaja Saponins adverse effects, Quillaja Saponins immunology, Saponins chemistry, Saponins economics, Saponins isolation & purification, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Th1-Th2 Balance, Viral Vaccines administration & dosage, Bovine Virus Diarrhea-Mucosal Disease immunology, Immunity, Cellular immunology, Plant Extracts immunology, Quillaja chemistry, Saponins immunology, Viral Vaccines immunology
- Abstract
Saponin-based adjuvants are promising adjuvants that enhance both humoral and T-cell-mediated immunity. One of the most used natural products as vaccine adjuvants are Quillaja saponaria bark saponins and its fraction named Quil A®. Despite that, its use has been restricted for human use due to safety issues. As an alternative, our group has been studying the congener species Quillaja brasiliensis saponins and its performance as vaccine adjuvants, which have shown to trigger humoral and cellular immune responses comparable to Quil A® but with milder side effects. Here, we studied a semi purified aqueous extract (AE) and a previously little characterized saponin-enriched fraction (QB-80) from Q. brasiliensis as vaccine adjuvants and an inactivated virus (bovine viral diarrhea virus, BVDV) antigen co-formulated in experimental vaccines in mice model. For the first time, we show the spectra pattern of the Q. brasiliensis saponins by MALDI-TOF, a novel and cost-effective method that could be used to characterize different batches during saponins production. Both AE and QB-80 exhibited noteworthy chemical similarities to Quil A®. In addition, the haemolytic activity and toxicity were assessed, showing that both AE and QB-80 were less toxic than Quil A®. When subcutaneously inoculated in mice, both fractions promoted long-term strong antibody responses encompassing specific IgG1 and IgG2a, enhanced the avidity of IgG antibodies, induced a robust DTH reaction and significantly increased IFN-ɣ production in T CD4
+ and T CD8+ cells. Furthermore, we have proven herein that AE has the potential to promote dose-sparing, substantially reducing the dose of antigen required for the BVDV vaccines and still eliciting a mixed Th1/Th2 strong immune response. Based on these results, and considering that AE is a raw extract, easier and cheaper to produce than commercially available saponins, this product can be considered as candidate to be escalated from experimental to industrial uses., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2018
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12. Events Associated with Early Age-Related Decline in Adventitious Rooting Competence of Eucalyptus globulus Labill.
- Author
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Aumond ML Jr, de Araujo AT Jr, de Oliveira Junkes CF, de Almeida MR, Matsuura HN, de Costa F, and Fett-Neto AG
- Abstract
The development of adventitious roots is affected by several factors, including the age of the cutting donor plant, which negatively affects rooting capacity. Eucalyptus globulus quickly loses rooting capacity of cuttings as the donor plant ages, although the molecular and biochemical mechanisms behind this process are still unclear. To better understand the bases of rooting competence loss in E. globulus , the time required for a significant decline in rhizogenic ability without exogenous auxin was determined in microcuttings derived from donor plants of different ages after sowing. Tip cuttings of donor plants were severed before and after loss of rooting competence of microcuttings to test the hypothesis that auxin and carbohydrate homeostasis regulate rooting competence decline. There were no significant changes in concentration of carbohydrates, flavonoids, or proteins before and after the loss of rooting capacity. Peroxidase (EC 1.11.1.7) total activity increased with loss of rooting competence. Auxin concentration showed the opposite pattern. In good agreement, TAA1 , a key gene in auxin biosynthesis, had lower expression after loss of rooting capacity. The same applied to the auxin receptor gene TIR1 , suggesting reduced auxin sensitivity. On the other hand, genes associated with auxin response repression ( TPL , IAA12 ) or with the action of cytokinins, the rhizogenesis inhibitor-related ARR1 , showed higher expression in plants with lower rooting competence. Taken together, data suggest that age negatively affects E. globulus rooting by a combination of factors. Decreased endogenous auxin concentration, possibly caused by less biosynthesis, lower auxin sensitivity, higher expression of genes inhibiting auxin action, as well as of genes related to the action of cytokinins, appear to play roles in this process.
- Published
- 2017
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13. Molecular cloning of an ester-forming triterpenoid: UDP-glucose 28-O-glucosyltransferase involved in saponin biosynthesis from the medicinal plant Centella asiatica.
- Author
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de Costa F, Barber CJS, Kim YB, Reed DW, Zhang H, Fett-Neto AG, and Covello PS
- Subjects
- Centella genetics, Cloning, Molecular, Glucosyltransferases genetics, Plant Proteins genetics, Plants, Medicinal genetics, Centella enzymology, Centella metabolism, Glucosyltransferases metabolism, Plant Proteins metabolism, Plants, Medicinal enzymology, Plants, Medicinal metabolism, Saponins biosynthesis, Triterpenes metabolism
- Abstract
Triterpene saponins include bioactive compounds with structures consisting of triterpene aglycones (sapogenins) and one or more sugar moieties linked through acetal or ester glycosidic linkages at one or more sites. Centella asiatica (L.) Urban is a medicinal plant that contains bioactive ursane-type saponins, such as madecassoside and asiaticoside. In this work, glucosylation of triterpenoids in C. asiatica was investigated starting with plant extracts. An enzyme capable of glucosylating asiatic and madecassic acids was partially purified. Proteomics methods and cDNA sequence data were employed as tools to obtain a full-length cDNA clone encoding a glucosyltransferase. The recombinant gene product, UGT73AD1, was functionally expressed in Escherichia coli and purified by immobilized metal-affinity chromatography. Purified recombinant UGT73AD1 was found to have a narrow specificity, glucosylating asiatic and madecassic acids at the C28 carboxyl. mRNA accumulated in all tissues tested (leaves, stems, roots and flowers), with highest expression in leaves. Thus, UGT73AD1 was identified as a triterpenoid carboxylic acid: UDP-glucose 28-O-glucosyltransferase that appears to be involved in saponin biosynthesis in C. asiatica., (Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)
- Published
- 2017
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14. Purification of an Immunoadjuvant Saponin Fraction from Quillaja brasiliensis Leaves by Reversed-Phase Silica Gel Chromatography.
- Author
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Yendo AC, de Costa F, Kauffmann C, Fleck JD, Gosmann G, and Fett-Neto AG
- Subjects
- Chromatography, Reverse-Phase methods, Plant Leaves chemistry, Quillaja chemistry, Saponins chemistry, Saponins isolation & purification, Silicon Dioxide
- Abstract
Saponins include a large variety of molecules that find several applications in pharmacology. The use of Quillaja saponaria saponins as immunological adjuvants in vaccines is of interest due to their capacity to stimulate both humoral and cellular responses. The congener species Q. brasiliensis has saponins with chemical similarities and adjuvant activity comparable to that of Q. saponaria fraction Quil-A
® , with additional advantages of showing lower toxicity and reduced hemolytic activity. Here we describe in detail the methods for preparing the aqueous extract from Q. brasiliensis leaves, as well as the purification of the bioactive saponin fraction QB-90 using silica reversed-phase chromatography.- Published
- 2017
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15. Reference Genes for qPCR Analysis in Resin-Tapped Adult Slash Pine As a Tool to Address the Molecular Basis of Commercial Resinosis.
- Author
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de Lima JC, de Costa F, Füller TN, Rodrigues-Corrêa KC, Kerber MR, Lima MS, Fett JP, and Fett-Neto AG
- Abstract
Pine oleoresin is a major source of terpenes, consisting of turpentine (mono- and sesquiterpenes) and rosin (diterpenes) fractions. Higher oleoresin yields are of economic interest, since oleoresin derivatives make up a valuable source of materials for chemical industries. Oleoresin can be extracted from living trees, often by the bark streak method, in which bark removal is done periodically, followed by application of stimulant paste containing sulfuric acid and other chemicals on the freshly wounded exposed surface. To better understand the molecular basis of chemically-stimulated and wound induced oleoresin production, we evaluated the stability of 11 putative reference genes for the purpose of normalization in studying Pinus elliottii gene expression during oleoresinosis. Samples for RNA extraction were collected from field-grown adult trees under tapping operations using stimulant pastes with different compositions and at various time points after paste application. Statistical methods established by geNorm, NormFinder, and BestKeeper softwares were consistent in pointing as adequate reference genes HISTO3 and UBI. To confirm expression stability of the candidate reference genes, expression profiles of putative P. elliottii orthologs of resin biosynthesis-related genes encoding Pinus contorta β-pinene synthase [PcTPS-(-)β-pin1], P. contorta levopimaradiene/abietadiene synthase (PcLAS1), Pinus taeda α-pinene synthase [PtTPS-(+)αpin], and P. taeda α-farnesene synthase (PtαFS) were examined following stimulant paste application. Increased oleoresin yields observed in stimulated treatments using phytohormone-based pastes were consistent with higher expression of pinene synthases. Overall, the expression of all genes examined matched the expected profiles of oleoresin-related transcript changes reported for previously examined conifers.
- Published
- 2016
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16. A rabies vaccine adjuvanted with saponins from leaves of the soap tree (Quillaja brasiliensis) induces specific immune responses and protects against lethal challenge.
- Author
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Yendo AC, de Costa F, Cibulski SP, Teixeira TF, Colling LC, Mastrogiovanni M, Soulé S, Roehe PM, Gosmann G, Ferreira FA, and Fett-Neto AG
- Subjects
- Adjuvants, Immunologic administration & dosage, Animals, Antibodies, Viral blood, Brain virology, Female, Immunoglobulin G blood, Mice, Plant Extracts administration & dosage, Quillaja chemistry, Quillaja Saponins administration & dosage, RNA, Viral isolation & purification, Adjuvants, Immunologic chemistry, Plant Extracts chemistry, Plant Leaves chemistry, Quillaja Saponins chemistry, Rabies prevention & control, Rabies Vaccines immunology
- Abstract
Quillaja brasiliensis (Quillajaceae) is a saponin producing species native from southern Brazil and Uruguay. Its saponins are remarkably similar to those of Q. saponaria, which provides most of the saponins used as immunoadjuvants in vaccines. The immunostimulating capacities of aqueous extract (AE) and purified saponin fraction (QB-90) obtained from leaves of Q. brasiliensis were favorably comparable to those of a commercial saponin-based adjuvant preparation (Quil-A) in experimental vaccines against bovine herpesvirus type 1 and 5, poliovirus and bovine viral diarrhea virus in mice model. Herein, the immunogenicity and protection efficacy of rabies vaccines adjuvanted with Q. brasiliensis AE and its saponin fractions were compared with vaccines adjuvanted with either commercial Quil-A or Alum. Mice were vaccinated with one or two doses (on days 0 and 14) of one of the different vaccines and serum levels of total IgG, IgG1 and IgG2a were quantified over time. A challenge experiment with a lethal dose of rabies virus was carried out with the formulations. Viral RNA detection in the brain of mice was performed by qPCR, and RNA copy-numbers were quantified using a standard curve of in vitro transcribed RNA. All Q. brasiliensis saponin-adjuvanted vaccines significantly enhanced levels of specific IgG isotypes when compared with the no adjuvant group (P ≤ 0.05). Overall, one or two doses of saponin-based vaccine were efficient to protect against the lethal rabies exposure. Both AE and saponin fractions from Q. brasiliensis leaves proved potent immunological adjuvants in vaccines against a lethal challenge with a major livestock pathogen, hence confirming their value as competitive or complementary sustainable alternatives to saponins of Q. saponaria., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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17. Quillaja brasiliensis saponins induce robust humoral and cellular responses in a bovine viral diarrhea virus vaccine in mice.
- Author
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Cibulski SP, Silveira F, Mourglia-Ettlin G, Teixeira TF, dos Santos HF, Yendo AC, de Costa F, Fett-Neto AG, Gosmann G, and Roehe PM
- Subjects
- Animals, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Cattle, Cytokines metabolism, Hypersensitivity, Delayed, Immunoglobulin G blood, Interferon-gamma immunology, Lymphocyte Activation, Mice, Plant Extracts immunology, Plant Leaves chemistry, Quillaja chemistry, Quillaja Saponins administration & dosage, Quillaja Saponins isolation & purification, Th1 Cells immunology, Viral Vaccines administration & dosage, Adjuvants, Immunologic administration & dosage, Antibodies, Viral blood, Diarrhea Virus 1, Bovine Viral immunology, Immunity, Cellular, Immunity, Humoral, Quillaja Saponins immunology, Viral Vaccines immunology
- Abstract
A saponin fraction extracted from Quillaja brasiliensis leaves (QB-90) and a semi-purified aqueous extract (AE) were evaluated as adjuvants in a bovine viral diarrhea virus (BVDV) vaccine in mice. Animals were immunized on days 0 and 14 with antigen plus either QB-90 or AE or an oil-adjuvanted vaccine. Two-weeks after boosting, antibodies were measured by ELISA; cellular immunity was evaluated by DTH, lymphoproliferation, cytokine release and single cell IFN-γ production. Serum anti-BVDV IgG, IgG1 and IgG2b were significantly increased in QB-90- and AE-adjuvanted vaccines. A robust DTH response, increased splenocyte proliferation, Th1-type cytokines and enhanced production of IFN-γ by CD4(+) and CD8(+) T lymphocytes were detected in mice that received QB-90-adjuvanted vaccine. The AE-adjuvanted preparation stimulated humoral responses but not cellular immune responses. These findings reveal that QB-90 is capable of stimulating both cellular and humoral immune responses when used as adjuvant., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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18. From Plant Extract to a cDNA Encoding a Glucosyltransferase Candidate: Proteomics and Transcriptomics as Tools to Help Elucidate Saponin Biosynthesis in Centella asiatica.
- Author
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de Costa F, Barber CJ, Reed DW, and Covello PS
- Subjects
- Centella chemistry, Computational Biology, Enzyme Activation, Glucosyltransferases chemistry, Plant Extracts, Plant Leaves chemistry, Plant Leaves genetics, Plant Leaves metabolism, Plants, Medicinal chemistry, Plants, Medicinal genetics, Plants, Medicinal metabolism, Saponins biosynthesis, Centella genetics, Centella metabolism, DNA, Complementary, Gene Expression Profiling methods, Glucosyltransferases genetics, Glucosyltransferases metabolism, Proteomics methods
- Abstract
Centella asiatica (L.) Urban (Apiaceae), a small annual plant that grows in India, Sri Lanka, Malaysia, and other parts of Asia, is well-known as a medicinal herb with a long history of therapeutic uses. The bioactive compounds present in C. asiatica leaves include ursane-type triterpene sapogenins and saponins-asiatic acid, madecassic acid, asiaticoside, and madecassoside. Various bioactivities have been shown for these compounds, although most of the steps in the biosynthesis of triterpene saponins, including glycosylation, remain uncharacterized at the molecular level. This chapter describes an approach that integrates partial enzyme purification, proteomics methods, and transcriptomics, with the aim of reducing the number of cDNA candidates encoding for a glucosyltransferase involved in saponin biosynthesis and facilitating the elucidation of the pathway in this medicinal plant.
- Published
- 2016
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19. A Modified Protocol for High-Quality RNA Extraction from Oleoresin-Producing Adult Pines.
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de Lima JC, Füller TN, de Costa F, Rodrigues-Corrêa KC, and Fett-Neto AG
- Subjects
- Buffers, Pinus metabolism, Plant Extracts biosynthesis, Pinus genetics, Plant Extracts genetics, RNA, Plant genetics, RNA, Plant isolation & purification
- Abstract
RNA extraction resulting in good yields and quality is a fundamental step for the analyses of transcriptomes through high-throughput sequencing technologies, microarray, and also northern blots, RT-PCR, and RTqPCR. Even though many specific protocols designed for plants with high content of secondary metabolites have been developed, these are often expensive, time consuming, and not suitable for a wide range of tissues. Here we present a modification of the method previously described using the commercially available Concert™ Plant RNA Reagent (Invitrogen) buffer for field-grown adult pine trees with high oleoresin content.
- Published
- 2016
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20. Stimulant Paste Preparation and Bark Streak Tapping Technique for Pine Oleoresin Extraction.
- Author
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Füller TN, de Lima JC, de Costa F, Rodrigues-Corrêa KC, and Fett-Neto AG
- Subjects
- Chemical Fractionation methods, Pinus chemistry, Plant Bark chemistry, Plant Extracts chemistry
- Abstract
Tapping technique comprises the extraction of pine oleoresin, a non-wood forest product consisting of a complex mixture of mono, sesqui, and diterpenes biosynthesized and exuded as a defense response to wounding. Oleoresin is used to produce gum rosin, turpentine, and their multiple derivatives. Oleoresin yield and quality are objects of interest in pine tree biotechnology, both in terms of environmental and genetic control. Monitoring these parameters in individual trees grown in the field provides a means to examine the control of terpene production in resin canals, as well as the identification of genetic-based differences in resinosis. A typical method of tapping involves the removal of bark and application of a chemical stimulant on the wounded area. Here we describe the methods for preparing the resin-stimulant paste with different adjuvants, as well as the bark streaking process in adult pine trees.
- Published
- 2016
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21. Purification of a Recombinant Polyhistidine-Tagged Glucosyltransferase Using Immobilized Metal-Affinity Chromatography (IMAC).
- Author
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de Costa F, Barber CJ, Pujara PT, Reed DW, and Covello PS
- Subjects
- Glucosyltransferases genetics, Histidine genetics, Recombinant Fusion Proteins genetics, Chromatography, Affinity methods, Glucosyltransferases isolation & purification, Metals chemistry, Recombinant Fusion Proteins isolation & purification
- Abstract
Short peptide tags genetically fused to recombinant proteins have been widely used to facilitate detection or purification without the need to develop specific procedures. In general, an ideal affinity tag would allow the efficient purification of tagged proteins in high yield, without affecting its function. Here, we describe the purification steps to purify a recombinant polyhistidine-tagged glucosyltransferase from Centella asiatica using immobilized metal affinity chromatography.
- Published
- 2016
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22. Comparative transcriptional analysis provides new insights into the molecular basis of adventitious rooting recalcitrance in Eucalyptus.
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de Almeida MR, de Bastiani D, Gaeta ML, de Araújo Mariath JE, de Costa F, Retallick J, Nolan L, Tai HH, Strömvik MV, and Fett-Neto AG
- Subjects
- Eucalyptus anatomy & histology, Eucalyptus growth & development, Eucalyptus metabolism, Laser Capture Microdissection, Plant Roots anatomy & histology, Plant Roots genetics, Plant Roots growth & development, Plant Roots metabolism, Eucalyptus genetics, Gene Expression Regulation, Plant, Indoleacetic Acids metabolism, Plant Growth Regulators metabolism
- Abstract
Adventitious rooting (AR) is essential in clonal propagation. Eucalyptus globulus is relevant for the cellulose industry due to its low lignin content. However, several useful clones are recalcitrant to AR, often requiring exogenous auxin, adding cost to clonal garden operations. In contrast, E. grandis is an easy-to-root species widely used in clonal forestry. Aiming at contributing to the elucidation of recalcitrance causes in E. globulus, we conducted a comparative analysis with these two species differing in rooting competence, combining gene expression and anatomical techniques. Recalcitrance in E. globulus is reversed by exposure to exogenous indole-3-acetic acid (IAA), which promotes important gene expression modifications in both species. The endogenous content of IAA was significantly higher in E. grandis than in E. globulus. The cambium zone was identified as an active area during AR, concentrating the first cell divisions. Immunolocalization assay showed auxin accumulation in cambium cells, further indicating the importance of this region for rooting. We then performed a cambium zone-specific gene expression analysis during AR using laser microdissection. The results indicated that the auxin-related genes TOPLESS and IAA12/BODENLOS and the cytokinin-related gene ARR1may act as negative regulators of AR, possibly contributing to the hard-to-root phenotype of E. globulus., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
23. Alternative inactivated poliovirus vaccines adjuvanted with Quillaja brasiliensis or Quil-a saponins are equally effective in inducing specific immune responses.
- Author
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de Costa F, Yendo AC, Cibulski SP, Fleck JD, Roehe PM, Spilki FR, Gosmann G, and Fett-Neto AG
- Subjects
- Animals, Antibodies, Viral immunology, Antibody Specificity immunology, Antigens, Viral immunology, Cytokines genetics, Cytokines metabolism, Disease Models, Animal, Female, Gene Expression, Hypersensitivity, Delayed immunology, Immunity, Mucosal, Immunization, Immunoglobulin A immunology, Immunoglobulin G immunology, Mice, Poliomyelitis genetics, Poliomyelitis immunology, Quillaja chemistry, Quillaja Saponins, Adjuvants, Immunologic, Poliomyelitis prevention & control, Poliovirus Vaccine, Inactivated immunology, Quillaja immunology, Saponins immunology
- Abstract
Inactivated polio vaccines (IPV) have an important role at the final stages of poliomyelitis eradication programs, reducing the risks associated with the use of attenuated polio vaccine (OPV). An affordable option to enhance vaccine immunogenicity and reduce costs of IPV may be the use of an effective and renewable adjuvant. In the present study, the adjuvant activity of aqueous extract (AE) and saponin fraction QB-90 from Quillaja brasiliensis using poliovirus antigen as model were analyzed and compared to a preparation adjuvanted with Quil-A, a well-known saponin-based commercial adjuvant. Experimental vaccines were prepared with viral antigen plus saline (control), Quil-A (50 µg), AE (400 µg) or QB-90 (50 µg). Sera from inoculated mice were collected at days 0, 28, 42 and 56 post-inoculation of the first dose of vaccine. Serum levels of specific IgG, IgG1 and IgG2a were significantly enhanced by AE, QB-90 and Quil-A compared to control group on day 56. The magnitude of enhancement was statistically equivalent for QB-90 and Quil-A. The cellular response was evaluated through DTH and analysis of IFN-γ and IL-2 mRNA levels using in vitro reestimulated splenocytes. Results indicated that AE and QB-90 were capable of stimulating the generation of Th1 cells against the administered antigen to the same extent as Quil-A. Mucosal immune response was enhanced by the vaccine adjuvanted with QB-90 as demonstrated by increases of specific IgA titers in bile, feces and vaginal washings, yielding comparable or higher titers than Quil-A. The results obtained indicate that saponins from Q. brasiliensis are potent adjuvants of specific cellular and humoral immune responses and represent a viable option to Quil-A.
- Published
- 2014
- Full Text
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24. Accumulation of a bioactive triterpene saponin fraction of Quillaja brasiliensis leaves is associated with abiotic and biotic stresses.
- Author
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de Costa F, Yendo AC, Fleck JD, Gosmann G, and Fett-Neto AG
- Subjects
- Adjuvants, Immunologic metabolism, Cyclopentanes pharmacology, Oxylipins pharmacology, Plant Leaves drug effects, Plant Leaves radiation effects, Plant Shoots drug effects, Plant Shoots metabolism, Plant Shoots radiation effects, Polyethylene Glycols metabolism, Quillaja drug effects, Quillaja radiation effects, Salicylic Acid pharmacology, Saponins metabolism, Sodium Chloride pharmacology, Sorbitol pharmacology, Sound, Ultraviolet Rays, Plant Leaves metabolism, Quillaja metabolism, Quillaja Saponins metabolism, Stress, Mechanical, Stress, Physiological, Triterpenes metabolism
- Abstract
The saponins from leaves of Quillaja brasiliensis, a native species from Southern Brazil, show structural and functional similarities to those of Quillaja saponaria barks, which are currently used as adjuvants in vaccine formulations. The accumulation patterns of an immunoadjuvant fraction of leaf triterpene saponins (QB-90) in response to stress factors were examined, aiming at understanding the regulation of accumulation of these metabolites. The content of QB-90 in leaf disks was significantly increased by application of different osmotic stress agents, such as sorbitol, sodium chloride and polyethylene glycol in isosmotic concentrations. Higher yields of bioactive saponins were also observed upon exposure to salicylic acid, jasmonic acid, ultrasound and UV-C light. Experiments with shoots indicated a significant increase in QB-90 yields with moderate increases in white light irradiance and by mechanical damage applied to leaves. The increased accumulation of these terpenes may be part of a defense response. The results herein described may contribute to further advance knowledge on the regulation of accumulation of bioactive saponins, and at defining strategies to improve yields of these useful metabolites., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)
- Published
- 2013
- Full Text
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25. Determination of new immunoadjuvant saponin named QB-90, and analysis of its organ-specific distribution in Quillaja brasiliensis by HPLC.
- Author
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Fleck JD, de Costa F, Yendo AC, Segalin J, Dalla Costa TC, Fett-Neto AG, and Gosmann G
- Subjects
- Plant Leaves chemistry, Adjuvants, Immunologic chemistry, Chromatography, High Pressure Liquid methods, Quillaja chemistry, Saponins chemistry
- Abstract
An LC method was developed and validated in order to quantify the saponin purified fraction named QB-90 obtained from the aqueous extracts of Quillaja brasiliensis leaves. Previously, QB-90 was shown to be active as adjuvant in an experimental vaccine for herpesvirus bovine type 1 in mice. The analysis was performed using an RP-8 column with acetonitrile:water isocratic elution at 214 nm. The standard curve for QB-90 was linear over the range of 0.8-10 µg mL(-1) (r = 0.9996). The aqueous extract showed linear response in the range of 50-1000 µg mL(-1) (r = 0.9996). The proposed method showed adequate repeatability and intermediary precision. The limits of detection (LOD) and quantification (LOQ) were 0.074 and 0.248 µg mL(-1), respectively. This method was applied successfully to analyse QB-90 organ-specific distribution in field stands of Q. brasiliensis and in laboratory-grown seedlings. Leaves from young plants accumulated higher QB-90 amounts than leaves from adult trees.
- Published
- 2013
- Full Text
- View/download PDF
26. Immunoadjuvant and anti-inflammatory plant saponins: characteristics and biotechnological approaches towards sustainable production.
- Author
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de Costa F, Yendo AC, Fleck JD, Gosmann G, and Fett-Neto AG
- Subjects
- Adjuvants, Immunologic isolation & purification, Animals, Anti-Inflammatory Agents isolation & purification, Biotechnology, Humans, Plant Cells metabolism, Plant Roots cytology, Plant Roots metabolism, Saponins chemistry, Saponins pharmacology, Adjuvants, Immunologic chemistry, Anti-Inflammatory Agents chemistry, Plants, Medicinal chemistry, Saponins biosynthesis
- Abstract
Saponins can be classified as triterpenoid (C30) or steroidal (C27), based on their carbon nucleus (aglycone). Sugar residues are linked to the aglycone, conferring an amphiphilic nature on these molecules, which is relevant for their biological activities. Saponins include a large variety of molecules that find several applications in pharmacology. Saponins have been shown to display immunoadjuvant, anti-inflammatory, antiplatelet, hypocholesterolemic, antitumoral, anti-HIV, antibacterial, insecticide, fungicide and anti-leishmanial activities. Anti-inflammatory medicines are increasingly demanded to treat various forms of arthritis in aging and obese populations and to help reduce the doses and duration of conventional corticotherapy with less side effects and without immunosuppression. The vaccine market for both human and veterinary uses is close to US$ 15 billion, progressively inflated by the recurrent threat of global pandemics.This paper provides an overview of recent advances (main focus on the last five years) on plant saponins that show anti-inflammatory and/or immunoadjuvant activities: source plants, isolation procedures, mechanism of action and biotechnological approaches towards sustainable production of bioactive saponins. Special attention is given to ginseng and Quillaja saponins. Strategies based on plant cultivation, cell and tissue culture, elicitation, and metabolic engineering for improved production of saponins are described. Future directions for research in the field and strategies to overcome bottlenecks are also discussed.
- Published
- 2011
- Full Text
- View/download PDF
27. Production of plant bioactive triterpenoid saponins: elicitation strategies and target genes to improve yields.
- Author
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Yendo AC, de Costa F, Gosmann G, and Fett-Neto AG
- Subjects
- Environment, Saponins chemistry, Triterpenes chemistry, Genes, Plant genetics, Genetic Engineering methods, Plants genetics, Plants metabolism, Saponins biosynthesis, Triterpenes metabolism
- Abstract
Triterpenoid saponins are a class of plant secondary metabolites with structure derived from the precursor oxidosqualene in which one or more sugar residues are added. They have a wide range of pharmacological applications, such as antiplatelet, hypocholesterolemic, antitumoral, anti-HIV, immunoadjuvant, anti-inflammatory, antibacterial, insecticide, fungicide and anti-leishmanial agents. Their accumulation in plant cells is stimulated in response to changes mediated by biotic and abiotic elicitors. The enhancement of saponin yields by methyl jasmonate in plants and cell cultures in several species indicates the involvement of these metabolites in plant defence mechanisms. The elucidation of their biosynthesis at the molecular level has advanced recently. Most studies to date have focused on the participation of early enzymes in the pathway, including oxidosqualene cyclase, squalene synthase and dammarenediol synthase, as well as in isolating and characterizing genes that encode beta-amyrin synthase. Yields of bioactive saponins in various plant species and experimental systems have been successfully increased by treating cells and tissues with jasmonate or by exposing these to oxidative stress. These elicitation and molecular studies are consolidating a robust knowledge platform from which to launch the development of improved sources for commercial supply of bioactive saponins.
- Published
- 2010
- Full Text
- View/download PDF
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