DEFAR - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531
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Item 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 VianaAntibiotic 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.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 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.