RESUMO
This study reports the isolation and identification of the endophytic fungus Exserohilum rostratum through molecular and morphological analysis using optical and transmission electron microscopy (TEM), as well as the procurement of its secondary metabolite monocerin, an isocoumarin derivative. Considering the previously observed biological activities of monocerin, this study was performed on human umbilical vein endothelial cells (HUVECs) that are widely used as an in vitro model for several different purposes. Important parameters, such as cell viability, senescence-associated ß-galactosidase, cellular proliferation by using 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE), apoptosis analysis with annexin, cellular morphology through scanning electron microscopy (SEM), and laser confocal analysis were evaluated after exposing the cells to monocerin. After 24 h of exposure to monocerin at 1.25 mM, there was more than 80% of cell viability and a low percentage of cells in the early and late apoptosis and necrosis. Monocerin increased cell proliferation and did not induce cell senescence. Morphological analysis showed cellular integrity. The study demonstrates aspects of the mechanism of action of monocerin on endothelial cell proliferation, suggesting the possibility of its pharmaceutical application, such as in regenerative medicine.
Assuntos
Senescência Celular , Lactonas , Humanos , Células Endoteliais da Veia Umbilical Humana , Células Cultivadas , Lactonas/farmacologia , Proliferação de CélulasRESUMO
In this study, 106 bacterial strains were isolated from rhizosphere of Deschampsia antarctica and used for the screening of potential antimicrobial compounds. Among all the bacterial strains, 61 (57.55%) were classified as Gram-positive, 34 (32.08%) as Gram-negative, and 11 (10.37%) did not grown under the laboratory culture conditions and were not classified. Organic crude extracts were analysed for potential antimicrobial activity and the B-22-EA ethyl acetate extract was the most effective inhibiting 84% of Escherichia coli growth, and Staphylococcus aureus, Pseudomonas aeruginosa and Micrococcus luteus by 31, 17 and 5%, respectively. The B-22-EA extract showed a MIC of 187 µg/mL on Cryptococcus neoformans, and of 438 µg/mL on Trichophyton rubrum. The strain, coded as B22, was classified as Gram-positive and the taxonomic analysis indicated that this strain belongs to the genera Janibacter, with 98.66% of similarity with Janibacter hoylei PVAS-1 and Janibacter limosus DSM 11140; 98.51% with Janibacter cremeus HR08-44, and 98.36% with Janibacter indicus 0704P10-1, Janibacter anophelis H2.16B and Janibacter terrae CS12. The cellular fatty acids (CFA) composition for B22 (Janibacter sp.) was determined by fatty acid methyl esters (FAME) using gas chromatography and compared with those species for which the B22 strain has a high level of similarity. The comparison among the different species from the genus Janibacter shows that there is a difference in their CFA composition and in their optimum temperature for growth, showing the high biodiversity, even for the same species. The data from this study are important and B-22 (Janibacter sp.) is an interesting source of antimicrobial compounds.
RESUMO
This study reports the isolation and identification of the endophytic fungus Exserohilum rostratum through molecular and morphological analysis using optical and transmission electron microscopy (TEM), as well as the procurement of its secondary metabolite monocerin, an isocoumarin derivative. Considering the previously observed biological activities of monocerin, this study was performed on human umbilical vein endothelial cells (HUVECs) that are widely used as an in vitro model for several different purposes. Important parameters, such as cell viability, senescence-associated β-galactosidase, cellular proliferation by using 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE), apoptosis analysis with annexin, cellular morphology through scanning electron microscopy (SEM), and laser confocal analysis were evaluated after exposing the cells to monocerin. After 24 h of exposure to monocerin at 1.25 mM, there was more than 80% of cell viability and a low percentage of cells in the early and late apoptosis and necrosis. Monocerin increased cell proliferation and did not induce cell senescence. Morphological analysis showed cellular integrity. The study demonstrates aspects of the mechanism of action of monocerin on endothelial cell proliferation, suggesting the possibility of its pharmaceutical application, such as in regenerative medicine.
RESUMO
Microorganisms are known as important sources of natural compounds that have been studied and applied for different purposes in distinct areas. Specifically, in the pharmaceutical area, fungi have been explored mainly as sources of antibiotics, antiviral, anti-inflammatory, enzyme inhibitors, hypercholesteremic, antineoplastic/antitumor, immunomodulators, and immunosuppressants agents. However, historically, the high demand for new antimicrobial and antitumor agents has not been sufficiently attended by the drug discovery process, highlighting the relevance of intensifying studies to reach sustainable employment of the huge world biodiversity, including the microorganisms. Therefore, this review describes the main approaches and tools applied in the search for bioactive secondary metabolites, as well as presents several examples of compounds produced by different fungi species with proven pharmacological effects and additional examples of fungal cytotoxic and antimicrobial molecules. The review does not cover all fungal secondary metabolites already described; however, it presents some reports that can be useful at any phase of the drug discovery process, mainly for pharmaceutical applications.
RESUMO
Microorganisms are known as important sources of natural compounds that have been studied and applied for different purposes in distinct areas. Specifically, in the pharmaceutical area, fungi have been explored mainly as sources of antibiotics, antiviral, anti-inflammatory, enzyme inhibitors, hypercholesteremic, antineoplastic/antitumor, immunomodulators, and immunosuppressants agents. However, historically, the high demand for new antimicrobial and antitumor agents has not been sufficiently attended by the drug discovery process, highlighting the relevance of intensifying studies to reach sustainable employment of the huge world biodiversity, including the microorganisms. Therefore, this review describes the main approaches and tools applied in the search for bioactive secondary metabolites, as well as presents several examples of compounds produced by different fungi species with proven pharmacological effects and additional examples of fungal cytotoxic and antimicrobial molecules. The review does not cover all fungal secondary metabolites already described; however, it presents some reports that can be useful at any phase of the drug discovery process, mainly for pharmaceutical applications.