DEFAR - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531
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Item Antioxidant study indicative of antibacterial and antimutagenic activities of an ellagitannin-rich aqueous extract from the leaves of Miconia latecrenata.(2019) Gontijo, Douglas da Costa; Gontijo, Pablo Costa; Brandão, Geraldo Célio; Diaz, Marisa Alves Nogueira; Oliveira, Alaíde Braga de; Fietto, Luciano Gomes; Leite, João Paulo VianaEthnopharmacological relevance: Several plant species of Miconia genus are commonly used in Brazilian folk medicine as anti-inflammatory agents and for the treatment of infectious diseases. Infusions and extracts of Miconia species are also reported as analgesic, antimicrobial, antimalarial, antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and antitumoral. Aim of the study; To determine the phytochemical composition of an aqueous extract of Miconia latecrenata leaves and to evaluate its antioxidant, antibacterial, antimutagenic and antigenotoxic activities. Materials and Methods: The following methods were used for the different effects: I) antioxidant - β-carotene/linoleic acid, lipid peroxidation, and DPPH• radical scavenging; II) antibacterial - agar well diffusion and MIC methods); III) antimutagenic assays - Ames Test; and IV) antigenotoxic - Plasmid cleavage test. The phytochemical analysis and phenolic quantification were carried out by UPLC-DAD-ESI-MS/MS and colorimetry, respectively. In addition, statistical correlation analysis was performed aiming to evaluate the Pearson correlation between phenolic compounds and biological assays. Results: A high content of tannins was observed and the ellagitannin isomers of 1,2,3,5-tris-galloyl-4,6-HHDP-glucose were identified as the main constituents of the leaves aqueous extract. High antioxidant effect, in different tests, high antibacterial activity to gram-positive and negative strains, as well as high antimutagenic activity were observed. Statistical analysis showed a high Pearson correlation for the tannin content in relation to the results of the antioxidant and antibacterial tests. In general, the antioxidant action of the aqueous extract showed low correlation with the antimutagenic activity. Conclusions: The present results confirmed the expectations regarding the pharmacological profile of M. latecrenata supporting its therapeutic potential in relation to ROS/RNS related disorders. Furthermore, the phenolic compounds of M. latecrenata can act, in turn, minimizing or inhibiting the biological macromolecules damage, especially DNA.Item Mangifera indica leaves extract and mangiferin modulate CB1 and PPARγ receptors and others markers associated with obesity.(2019) Brito, Larissa Froede; Gontijo, Douglas da Costa; Toledo, Renata Celi Lopes; Barcelos, Rafael Mazioli; Oliveira, Alaíde Braga de; Brandão, Geraldo Célio; Sousa, Lirlândia Pires de; Ribeiro, Sônia Machado Rocha; Leite, João Paulo Viana; Fietto, Luciano Gomes; Queiroz, José Humberto deThis study aimed phytochemical characterization (UPLC-DAD-MS/MS) of ethanolic extract of the leaves from Mangifera indica (EMI) and Mangiferin (MAN), analysis of the cytotoxic (MTT) and anti-inflammatory potential (expression of TNF-α) of EMI and MAN in vitro. In addition, was evaluate the effect on the mRNA expression of genes (CB1, PPARγ, adiponectin, resistin and leptin) associated with adipogenesis in adipose tissue of rats fed a cafeteria diet. Thus, wistar rats were treated by gavage with EMI and MAN for several days (according to the post and co-treatments). The adipose tissue was weighed and checked the expression of different markers by RT-PCR. The presence of MAN as major compound in EMI was verified. Both EMI and MAN were not cytotoxic, with lower EMI expression of TNF-α. Furthermore, EMI and MAN had proadipogenic action on post-treatment, while in the co-treatment, EMI attenuated the effect of adipogenesis and MAN increased the adipogenic process.Item Phytochemical characterization and antioxidant, antibacterial and antimutagenic activities of aqueous extract from leaves of Alchornea glandulosa.(2018) Gontijo, Douglas da Costa; Diaz, Marisa Alves Nogueira; Brandão, Geraldo Célio; Gontijo, Pablo da Costa; Oliveira, Alaide Braga de; Fietto, Luciano Gomes; Leite, João Paulo VianaPlant extracts exist as a complex matrix which serves as a source of numerous bioactive metabolites. The ultra performance liquid chromatography with diode-array detection-coupled electrospray ionization-mass spectrometry/mass spectrometry technique was used to characterize the aqueous extract from leaves of Alchornea glandulosa (EAG), a species popularly used to treat gastrointestinal problems as an antiulcer agent. Quantification of phenolic derivatives was determined using Folin–Ciocalteu and aluminum trichloride (AlCl3) methods. In addition, antioxidant (2,2-diphenyl-1-picrylhydrazyl [DPPH• ] radical scavenging, β-carotene–linoleic acid, and lipid peroxidation), antibacterial (agar well diffusion method and minimum inhibitory concentration), antimutagenic (Ames test), and antigenotoxic (plasmid cleavage) assays were also performed on this plant extract. The ellagitannin tris-galloyl-hexahydroxydiphenic acid-glucose was identified as the predominant compound along with tannins as majority metabolites. EAG showed high antioxidant activity accompanied by moderate antibacterial activity against Staphylococcus aureus. The highest antimutagenic activity was observed for TA97 strain without metabolic activation (S9) and with metabolic activation, TA100 and TA102 were completely inhibited. In addition, EAG exhibited potential signs of antigenotoxic action. The high antioxidant and antimutagenic activity observed for EAG suggests important therapeutic uses that still need to be verified in future studies.Item Identification of phenolic compounds and biologically related activities from Ocotea odorifera aqueous extract leaves.(2017) Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Gontijo, Pablo Costa; Oliveira, Alaíde Braga de; Diaz, Marisa Alves Nogueira; Fietto, Luciano Gomes; Leite, João Paulo VianaOcotea odorifera (Vell.) Rohwer is popularly used as food and flavoring. The aim of this study was to determine the chemical composition of the aqueous extract from O. odorifera leaves and evaluate the correlation of their phytochemical composition and biological activities. The antioxidant effect was determined by DPPH radical scavenging, b-carotene-linoleic acid and lipid peroxidation assays; the antibacterial activity was evaluated by the hole plate and MIC techniques and the antimutagenic activity was evaluated by the Ames test. Identification of phytochemicals was performed by LC–ESI/MS and the correlation between the phytochemical composition of the extract and the evaluated activities. The results allowed the identification of 13 phenolic compounds in the extract that exhibited high antioxidant activity and moderate antibacterial and antimutagenic action. Statistical analyses showed correlation of the total phenolic content with biologically related activities. The phytochemical analyses, together with the biological results, support the popular use of O. odorifera.Item Intracellular signal triggered by cholera toxin in Saccharomyces boulardii and Saccharomyces cerevisiae.(1998) Brandão, Rogélio Lopes; Castro, Ieso de Miranda; Bambirra, Eduardo Alves; Amaral, Sheila Coutinho; Fietto, Luciano Gomes; Trópia, Maria José Magalhães; Neves, Maria José; Santos, Raquel Gouvêa dos; Gomes, Newton Carlos Marcial; Nicoli, Jacques RobertAs is the case for Saccharomyces boulardii, Saccharomyces cerevisiae W303 protects Fisher rats against cholera toxin (CT). The addition of glucose or dinitrophenol to cells of S. boulardii grown on a nonfermentable carbon source activated trehalase in a manner similar to that observed for S. cerevisiae. The addition of CT to the same cells also resulted in trehalase activation. Experiments performed separately on the A and B subunits of CT showed that both are necessary for activation. Similarly, the addition of CT but not of its separate subunits led to a cyclic AMP (cAMP) signal in both S. boulardii and S. cerevisiae. These data suggest that trehalase stimulation by CT probably occurred through the cAMP-mediated protein phosphorylation cascade. The requirement of CT subunit B for both the cAMP signal and trehalase activation indicates the presence of a specific receptor on the yeasts able to bind to the toxin, a situation similar to that observed for mammalian cells. This hypothesis was reinforced by experiments with 125I-labeled CT showing specific binding of the toxin to yeast cells. The adhesion of CT to a receptor on the yeast surface through the B subunit and internalization of the A subunit (necessary for the cAMP signal and trehalase activation) could be one more mechanism explaining protection against the toxin observed for rats treated with yeasts.Item Deficiency of Pkc1 activity affects glycerol metabolism in Saccharomices cerevisiae.(2005) Gomes, Katia das Neves; Freitas, Suzy Magaly Alves Cabral de; Pais, Thiago Martins; Fietto, Juliana Lopes Rangel; Totola, Antonio Helvecio; Arantes, Rosa Maria Esteves; Martins, António; Lucas, Cândida Manuel Ribeiro Simões; Schuller, Dorit; Casal, Margarida; Castro, Ieso de Miranda; Fietto, Luciano Gomes; Rogelio, Lopes BrandãoProtein kinase C is apparently involved in the control of many cellular systems: the cell wall integrity pathway, the synthesis of ribosomes, the appropriated reallocation of transcription factors under specific stress conditions and also the regulation of N-glycosylation activity. All these observations suggest the existence of additional targets not yet identified. In the context of the control of carbon metabolism, previous data had demonstrated that Pkc1p might play a central role in the control of cellular growth and metabolism in yeast. In particular, it has been suggested that it might be involved in the derepression of genes under glucose-repression by driving an appropriated subcellular localization of transcriptional factors, such as Mig1p. In this work, we show that a pkc1D mutant is unable to grow on glycerol because it cannot perform the derepression of the GUT1 gene that encodes glycerol kinase. Additionally, active transport is also partially affected. Using this phenotype, we were able to isolate a new pkc1D revertant. We also isolated two transformants identified as the nuclear exportin Msn5 and the histone deacetylase Hos2 extragenic suppressors of this mutation. Based on these results, we postulate that Pkc1p may be involved in the control of the cellular localization and/or regulation of the activity of nuclear proteins implicated in gene expression.Item Biochemical and molecular characterization of Saccharomyces cerevisiae strains obtained from sugar-cane juice fermentations and their impact in cachaça production.(2008) Oliveira, Valdinéia Aparecida de; Vicente, Maristela de Araújo; Fietto, Luciano Gomes; Castro, Ieso de Miranda; Coutrim, Maurício Xavier; Schüller, Dorit; Alves, Henrique; Casal, Margarida; Santos, Juliana de Oliveira; Araújo, Leandro Dias; Silva, Paulo Henrique Alves da; Brandão, Rogélio LopesSaccharomyces cerevisiae strains from different regions of Minas Gerais, Brazil, were isolated and characterized aiming at the selection of starter yeasts to be used in the production of cachac¸a, the Brazilian sugar cane spirit. The methodology established took into account the screening for biochemical traits desirable in a yeast cachac¸a producer, such as no H2S production, high tolerance to ethanol and high temperatures, high fermentative capacity, and the abilities to flocculate and to produce mycocins. Furthermore, the yeasts were exposed to drugs such as 5,5 ,5 -trifluor-D,L-leucine and cerulenin to isolate those that potentially overproduce higher alcohols and esters. The utilization of a random amplified polymorphic DNA-PCR method with primers based on intron splicing sites flanking regions of the COX1 gene, as well as microsatellite analysis, was not sufficient to achieve good differentiation among selected strains. In contrast, karyotype analysis allowed a clear distinction among all strains. Two selected strains were experimentally evaluated as cachac¸a producers. The results suggest that the selection of strains as fermentation starters requires the combined use of biochemical and molecular criteria to ensure the isolation and identification of strains with potential characteristics to produce cachac¸a with a higher quality standard.Item Strategies to select yeast starter cultures for production of flavour compounds in cachaça fermentations.(2012) Souza, Anderson Proust Gonçalves de; Vicente, Maristela de Araújo; Klein, Raphael Contelli; Fietto, Luciano Gomes; Coutrim, Maurício Xavier; Afonso, Robson José de Cássia Franco; Araújo, Leandro Dias; Alves, Paulo Henrique; Bouillet, Leoneide Érica Maduro; Castro, Ieso de Miranda; Brandão, Rogélio LopesIn this work, we have used classical genetics techniques to find improved starter strains to produce cachac¸a with superior sensorial quality. Our strategy included the selection of yeast strains resistant to 5,50,500-trifluor-D,L-leucine (TLF) and cerulenin, since these strains produce higher levels of higher alcohols and esters than parental strains. However, no clear relationship was observed when levels of flavoring compounds were compared with the levels expression of the genes (BAT1, BAT2, ATF2, EEB1 genes) involved with the biosynthesis of flavoring compounds. Furthermore, we determined the stability of phenotypes considered as the best indicators of the quality of the cachac¸a for a parental strain and its segregants. By applying the principal component analysis, a cluster of segregants, showing a high number of characteristics similar to the parental strain, was recognized. One segregant, that was resistant to TLF and cerulenin, also showed growth stability after six consecutive replications on plates containing high concentrations of sugar and ethanol. ‘‘Cachac¸a’’ produced at laboratory scale using a parental strain and this segregant showed a higher level of flavoring compounds. Both strains predominated in an open fermentative process through seven cycles, as was shown by mitochondrial restriction fragment length polymorphisms analysis. Based on the physical chemical composition of the obtained products, the results demonstrate the usefulness of the developed strategies for the selection of yeast strains to be used as starters in ‘‘cachac¸a’’ production.Item Kinetics and regulation of lactose transport and metabolism in Kluyveromyces lactis JA6.(2014) Santos, Ana Maria dos; Silveira, Wendel Batista da; Fietto, Luciano Gomes; Brandão, Rogélio Lopes; Castro, Ieso de MirandaKluyveromyces lactis strains are able to assimilate lactose. They have been used industrially to eliminate this sugar from cheese whey and in other industrial products. In this study, we investigated specific features and the kinetic parameters of the lactose transport system in K. lactis JA6. In lactose grown cells, lactose was transported by a system transport with a half-saturation constant (Ks) of 1.49 ± 0.38 mM and a maximum velocity (Vmax) of 0.96 ± 0.12 mmol. (g dry weight)-1 h-1 for lactose. The transport system was constitutive and energydependent. Results obtained by different approaches showed that the lactose transport system was regulated by glucose at the transcriptional level and by glucose and other sugars at a post-translational level. In K. lactis JA6, galactose metabolization was under glucose control. These findings indicated that the regulation of lactose-galactose regulon in K. lactis was similar to the regulation of galactose regulon in Saccharomyces cerevisiae.Item Calcium signaling and sugar-induced activation of plasma membrane H+-ATPase in Saccharomyces cerevisiae cells.(2006) Trópia, Maria José Magalhães; Cardoso, Anamaria de Souza; Tisi, Renata; Fietto, Luciano Gomes; Fietto, Juliana Lopes Rangel; Martegani, Enzo; Castro, Ieso de Miranda; Brandão, Rogélio LopesIn this work, we show that glucose-induced activation of plasma membrane H+-ATPase from Saccharomyces cerevisiae is strongly dependent on calcium metabolism and that the glucose sensor Snf3p works in a parallel way with the G protein Gpa2p in the control of the pathway. The role of Snf3p is played by the Snf3p C-terminal tail, since in a strain with the deletion of the SNF3 gene, but also expressing a chimera protein formed by Hxt1p (a glucose transporter) and the Snf3p C-terminal tail, a normal glucose-activation process can be observed. We present evidences indicating that Snf3p would be the sensor for the internal signal (phosphorylated sugars) of this pathway that would connect calcium signaling and activation of the plasma membrane ATPase. We also show that Snf3p could be involved in the control of Pmc1p activity that would regulate the calcium availability in the cytosol.