DEFAR - Artigos publicados em periódicos

URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531

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2017 - 201982020 - 20213

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Autor: search.filters.author.Gontijo, Douglas da Costa

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Agora exibindo 1 - 10 de 11
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    Extraction and fractionation effects on antiplasmodial activity and phytochemical composition of Palicourea hoffmannseggiana
    (2021) Ohashi, Leticia Hiromi; Gontijo, Douglas da Costa; Nascimento, Maria Fernanda Alves do; Margalho, Luciano Ferreira; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    The present study on Palicourea hoffmannseggiana, which was collected at Marapanim, state of Pará, Brazil, comprises the preparation of different stem and leaf extracts and fractions. Ethanol, hydroethanol, and water extracts were prepared by several methods and evaluated for in vitro activity against resistant Plasmodium falciparum (W2 strain), disclosing a low parasite growth inhibition effect ( < 50 %). Dereplication by UPLC-DAD-ESI −MS of the leaf ethanol extract showed the presence of two known alkaloids, lyalosidic and strictosidinic acids, along with a sinapoyl ester of lyalosidic acid, with m/z 719.33 [M +H] + , which is possibly a new monoterpene indole alkaloid representative. Sequential liquid-liquid acid-base alkaloid separations from the leaf ethanol extract as well as directly from leaf powder afforded fractions of increased parasite growth inhibition, reaching up to 92.5±0.7%. The most bioactive fractions were shown to contain the β-carboline alkaloids harmane and 4-methyl-β-carboline, along with N-methyl-tryptamine and N-acetyl-tryptamine, while monoterpene indole alkaloids were detected in inactive fractions of these processes. The present results demonstrate that these preliminary fractionation methods can lead to significantly active fractions supporting an adequate scale-up to carrying out the isolation of anti-plasmodial compounds.
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    Dereplication of Palicourea sessilis ethanol extracts by UPLC-DAD-ESI-MS/MS discloses the presence of hydroxycinnamic acid amides and the absence of monoterpene indole alkaloids.
    (2020) Samulski, Gabriela Bontempo; Gontijo, Douglas da Costa; Moreira, Nayara Couto; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    Secondary metabolites characterization of ethanol extracts of Palicourea sessilis leaves and stems by UPLC-DAD ESI-MS/MS led to putative identification of hydrolysable tannins in leaf extract (ESI negative mode) while hydroxycinnamic acid amides (HCA) such as N-p-coumaroylputrescine and N-feruloylagmatine were detected in both leaf and stems extracts in the ESI positive mode. Secondary metabolites quantification data showed a higher content of total phenolic in the leaf extract while the total alkaloids contents are statistically equivalent in both of the extracts. Furthermore, monoterpene indole alkaloids were not detected in both extracts. The presence of HCA is here firstly reported for a Palicourea species. This finding increases the classes of secondary metabolites occurring in this genus.
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    Antibacterial screening of plants from the Brazilian Atlantic Forest led to the identification of active compounds in Miconia latecrenata (DC.) Naudin.
    (2020) Rodrigues, Laís Azevedo; Almeida, Ayla das Chagas; Gontijo, Douglas da Costa; Salustiano, Iorrana Vieira; Almeida, Alisson Andrade; Brandão, Geraldo Célio; Ribon, Andrea de Oliveira Barros; Leite, João Paulo Viana
    Antibiotic resistance is a serious global threat to public health. This has promoted the research for new drug targets, and the use of other approaches, such as antimicrobial combined therapy. The present study evaluated the antibacterial activity of 88 extracts from Brazilian Atlantic Forest trees. The organic extract from leaves of Miconia latecrenata (EMl) was the most promising for inhibiting the growth of Staphylococcus aureus (0.3 mg/mL) and Pseudomonas aeruginosa (2.5 mg/mL). After the bioguided frac tionation of EMl and metabolite profiling performed by UPLC DAD-MS/MS, the ethyl acetate (AFMl) and aqueous (WFMl) frac tions showed a mixture of phenolic compounds derived from ellagic acid and quercetin. The MIC value of AFMl was two-times lower than EMl for P. aeruginosa, suggesting that these phenolic compounds can perform bioactivity. Furthermore, EMI and AFMl showed synergism with ampicillin and tetracycline for S. aureus and P. aeruginosa, respectively. These findings suggest that extract and fractions of the Miconia latecrenata leaves can be used as therapeutic antibacterial agents.
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    Himatanthus bracteatus stem extracts present antiflavivirus activity while an isolated sesquiterpene glucoside present only anti-Zika virus activity in vitro.
    (2019) Silva, Marlene Lourenço da; Stehmann, João Renato; Serafim, Mateus Sá Magalhães; Vale, Valdicley Vieira; Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Kroon, Erna Geessien; Oliveira, Alaíde Braga de
    The hexane and ethanol extracts from Himatanthus bracteatus (Apocynaceae) stems were evaluated for antiviral activity against Zika virus, yellow fever virus and dengue virus 2 and for cytotoxicity in Vero cells by MTT assay. The ethanol extract showed good antiviral activity against the three viruses with selective indexes (SI) > 10 and its fractionation led to the isolation of the known plumieride that was active only against Zika virus (SI of 15.97).
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    Phytochemistry and antiplasmodial activity of Xylopia sericea leaves.
    (2019) Gontijo, Douglas da Costa; Nascimento, Maria Fernanda Alves do; Brandão, Geraldo Célio; Oliveira, Alaide Braga de
    Aiming to investigate the antiplasmodial activity and the phytochemical composition of Xylopia sericea leaves, the essential oil and dichloromethane extract were analyzed by gas and liquid chromatography, respectively, both of them coupled to mass spectrometry, and were evaluated against the chloroquine-resistant Plasmodium falciparum strain (W2) and for cytotoxicity to HepG2 cells. Low growth inhibition of P. falciparum as well as low cytotoxicity to HepG2 cells were observed for the essential oil. The leaves dichloromethane extract showed moderate growth inhibition of P. falciparum and low cytotoxicity to HepG2 cells. Bioguided chromatographic fractionation of this extract led to fractions with increased antiplasmodial activity from which liriodenine (IC50 6.1 ± 0.1 μg/mL, CC50 > 1000.0 μg/mL, SI > 164), an aporphine alkaloid, and an acetogenin-rich fraction containing mainly isomers of annomontacin and 4-deoxy-annomontacin (IC50 22.7 ± 1.9 µg/mL, CC50 336.1 ± 15.5 µg/mL, SI = 15) might be highlighted for their antiplasmodial activity.
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    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 Viana
    Ethnopharmacological 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.
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    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 de
    This 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.
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    Bioprospection for antiplasmodial activity, and identification of bioactive metabolites of native plants species from the Mata Atlântica biome, Brazil.
    (2019) Gontijo, Douglas da Costa; Leite, João Paulo Viana; Nascimento, Maria Fernanda Alves do; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    A total of 33 extracts of eleven different plants species from Mata Atlântica biome, Brazil, and different fractions of the bioactive extracts were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by PfLDH method and cytotoxicity to HepG2 cells by the MTT assay, and chemically characterized by LC-DAD-ESI-MS/MS analysis. The results allowed the identification of Alchornea glandulosa, Miconia latecrenata, and Psychotria suterella as the most active plant species. Different flavonoids and tannins in Alchornea glandulosa and Miconia latecrenata besides alkaloids in Psychotria suterella were identified. Bioguided fractionation of A. glandulosa and M. latecrenata leaves extracts led to fractions exhibiting high parasite growth inhibition. Seven known alkaloids were identified in the P. suterella extract, and of these, only 5-carboxystrictosidine had been assayed for antiplasmodial activity what points to this species as the most promising among the eleven one assayed.
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    Antiplasmodial activity and cytotoxicity, isolation of active alkaloids, and dereplication of Xylopia sericea leaves ethanol extract by UPLC-DAD-ESI-MS/MS.
    (2019) Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Nascimento, Maria Fernanda Alves do; Oliveira, Alaide Braga de
    Objectives: To assess the antiplasmodial activity of the ethanol extract of Xylopia sericea leaves, Annonaceae, often associated with antimalarial use and to perform a bioguided isolation of active compounds. Methods: Dereplication of ethanol extract by the UPLC-DAD-ESI-MS/MS technique allowed the identification of the major constituents, isolation and identification of alkaloids. The antiplasmodial and cytotoxic activity of the extract, fractions and isolated compounds was evaluated against the chloroquine-resistant W2 strain Plasmodium falciparum and HepG2 cells, respectively. Key findings: Ethanol extract showed high reduction of parasitemia as well as moderate cytotoxicity (86.5 3.0% growth inhibition at 50 lg/ml and CC50 72.1 5.1 lg/ml, respectively). A total of eight flavonoids were identified, and two aporphine alkaloids, anonaine and O-methylmoschatoline, were isolated. Anonaine disclosed significant antiplasmodial effect and moderate cytotoxicity (IC50 23.2 2.7 lg/ml, CC50 38.3 2.3 lg/ml, SI 1.6) while O-methylmoschatoline was not active against P. falciparum and showed a low cytotoxicity (33.5 1.9% growth inhibition at 50 lg/ml, CC50 274.4 0.5 lg/ml). Conclusions: Characterization of Xylopia sericea leaves ethanol extract by UPLCDAD-ESI-MS/MS as well as its antiplasmodial activity and the occurrence of anonaine and O-methylmoschatoline in this Xylopia species are reported by the first time.
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    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 Viana
    Plant 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.