RESUMO
Metallocompounds have emerged as promising new anticancer agents, which can also exhibit properties to be used in photodynamic therapy. Here, we prepared two ruthenium-based compounds with a 2,2'-bipyridine ligand conjugated to an anthracenyl moiety. These compounds coded GRBA and GRPA contain 2,2'-bipyridine or 1,10-phenathroline as auxiliary ligands, respectively, which provide quite a distinct behavior. Notably, compound GRPA exhibited remarkably high photoproduction of singlet oxygen even in water (ÏΔ = 0.96), almost twice that of GRBA (ÏΔ = 0.52). On the other hand, this latter produced twice more superoxide and hydroxyl radical species than GRPA, which may be due to the modulation of their excited state. Interestingly, GRPA exhibited a modest binding to DNA (Kb = 4.51 × 104), while GRBA did not show a measurable interaction only noticed by circular dichroism measurements. Studies with bacteria showed a great antimicrobial effect, including a synergistic effect in combination with commercial antibiotics. Besides that, GRBA showed very low or no cytotoxicity against four mammalian cells, including a hard-to-treat MDA-MB-231, triple-negative human breast cancer. Potent activities were measured for GRBA upon blue light irradiation, where IC50 of 43 and 13 nmol L-1 were seen against hard-to-treat triple-negative human breast cancer (MDA-MB-231) and ovarian cancer cells (A2780), respectively. These promising results are an interesting case of a simple modification with expressive enhancement of biological activity that deserves further biological studies.
Assuntos
Antibacterianos , Antineoplásicos , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Estrutura Molecular , Testes de Sensibilidade Microbiana , Ensaios de Seleção de Medicamentos Antitumorais , Compostos de Rutênio/farmacologia , Compostos de Rutênio/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/síntese química , Rutênio/química , Rutênio/farmacologia , Proliferação de Células/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Processos Fotoquímicos , Sobrevivência Celular/efeitos dos fármacos , FotoquimioterapiaRESUMO
Antimicrobial resistance is a global health issue, in which microorganisms develop resistance to antimicrobial drugs, making infections more difficult to treat. This threatens the effectiveness of standard medical treatments and necessitates the urgent development of new strategies to combat resistant microbes. Studies have increasingly explored natural sources of new antimicrobial agents that harness the rich diversity of compounds found in plant species. This pursuit holds promise for the discovery of novel treatments for combating antimicrobial resistance. In this context, the chemical composition, antibacterial, and antibiofilm activities of the essential oil from Croton urticifolius Lam. leaves (CuEO) were evaluated. CuEO was extracted via hydrodistillation, and its chemical constituents were identified via gas chromatography-mass spectrometry (GC/MS). The antibacterial activity of CuEO was evaluated in a 96-well plate via the microdilution method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined. The effect of CuEO on biofilm formation was assessed by quantifying the biomass using crystal violet staining and viable cell counting. In addition, alterations in the cellular morphology of biofilms treated with CuEO were examined using scanning electron microscopy (SEM) and laser confocal microscopy. GC/MS analysis identified 26 compounds, with elemicine (39.72%); eucalyptol (19.03%), E-caryophyllene (5.36%), and methyleugenol (4.12%) as the major compounds. In terms of antibacterial activity, CuEO showed bacteriostatic effects against Staphylococcus aureus ATCC 700698, S. aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, and Escherichia coli ATCC 11303, and bactericidal activity against S. aureus ATCC 700698. In addition, CuEO significantly inhibited bacterial biofilm formation. Microscopic analysis showed that CuEO damaged the bacterial membrane by leaching out the cytoplasmic content. Therefore, the results of this study show that the essential oil of C. urticifolius may be a promising natural alternative for preventing infections caused by bacterial biofilms. This study is the first to report the antibiofilm activity of C. urticifolius essential oil.
Assuntos
Antibacterianos , Biofilmes , Croton , Testes de Sensibilidade Microbiana , Óleos Voláteis , Folhas de Planta , Biofilmes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Croton/química , Antibacterianos/farmacologia , Antibacterianos/química , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Cromatografia Gasosa-Espectrometria de Massas , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Membrana Celular/efeitos dos fármacosRESUMO
Antimicrobial resistance (AMR) presents a global challenge as microorganisms evolve to withstand the effects of antibiotics. In addition, the improper use of antibiotics significantly contributes to the AMR acceleration. Essential oils have garnered attention for their antimicrobial potential. Indeed, essential oils extracted from plants contain compounds that exhibit antibacterial activity, including against resistant microorganisms. Hence, this study aimed to evaluate the antimicrobial and antibiofilm activity of the essential oil (EO) extracted from Lippia grata and its combination with ampicillin against Staphylococcus aureus strains (ATCC 25923, ATCC 700698, and JKD6008). The plant material (leaves) was gathered in Mossoro, RN, and the EO was obtained using the hydrodistillation method with the Clevenger apparatus. The antimicrobial activity of the EO was assessed through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiofilm activity was evaluated by measuring biomass using crystal violet (CV) staining, viable cell counting, and analysis of preformed biofilms. In addition, the synergistic effects of the EO in combination with ampicillin were examined by scanning electron and confocal microscopy. The EO displayed a MIC value of 2.5 mg/mL against all tested S. aureus strains and an MBC only against S. aureus JKD6008 at 2.5 mg/mL. L. grata EO caused complete biofilm inhibition at concentrations ranging from 10 to 0.312 mg/mL against S. aureus ATCC 25923 and 10 to 1.25 mg/mL against S. aureus ATCC 700698 and S. aureus JKD6008. In the viable cell quantification assay, there was a reduction in CFU ranging from 1.0 to 8.0 logs. The combination of EO with ampicillin exhibited a synergistic effect against all strains. Moreover, the combination showed a significantly inhibiting biofilm formation and eradicating preformed biofilms. Furthermore, the EO and ampicillin (individually and in combination) altered the cellular morphology of S. aureus cells. Regarding the mechanism, the results revealed that L. grata EO increased membrane permeability and caused significant membrane damage. Concerning the synergy mechanism, the results revealed that the combination of EO and ampicillin increases membrane permeability and causes considerable membrane damage, further inhibiting bacteria synergistically. The findings obtained here suggest that L. grata EO in combination with ampicillin could be a viable treatment option against S. aureus infections, including MRSA strain.
Assuntos
Ampicilina , Antibacterianos , Biofilmes , Sinergismo Farmacológico , Lippia , Testes de Sensibilidade Microbiana , Óleos Voláteis , Staphylococcus aureus , Biofilmes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Ampicilina/farmacologia , Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Lippia/química , Extratos Vegetais/farmacologia , Folhas de Planta/químicaRESUMO
The emergence of infections caused by microorganisms in the oral cavity and increasing concerns regarding the use of antibiotics have resulted in the development of novel antimicrobial molecules, such as antimicrobial synthetic peptides. The purpose of this study was to evaluate the antimicrobial and antibiofilm activities of the native peptide KR-12 and its derivative, the synthetic peptide [W7]KR12-KAEK, against planktonic and biofilms Enterococcus faecalis strains. The methods used to evaluate the antimicrobial activity in planktonic cultures include minimum inhibitory concentration and minimum bactericidal concentration assays. The effects of [W7]KR12-KAEK on biofilm formation and mature biofilms were evaluated by quantifying biomass (crystal violet staining) and counting colony-forming units. Structural assessments of the biofilms and cellular morphological changes were performed using scanning electron microscopy. Peptide [W7]KR12-KAEK showed potential antimicrobial activity against planktonic cells. Interestingly, the native peptide KR-12 showed no antimicrobial activity. Moreover, it inhibited biofilm formation and disrupted the mature biofilms of E. faecalis strains. These results suggest that [W7]KR12-KAEK may be a potential molecule for the development of auxiliary antimicrobial therapies against oral infections.
Assuntos
Anti-Infecciosos , Enterococcus faecalis , Anti-Infecciosos/farmacologia , Peptídeos , Biofilmes , PlânctonRESUMO
Lectins presents the ability to interact with glycans and trigger varied responses, including the inhibition of the development of various pathogens. Structural studies of these proteins are essential to better understand their functions. In marine sponges, so far only a few lectins have their primary structures completely determined. Thus, the objective of this work was to structurally characterize and evaluate antibacterial potential, in association with different antibiotics, of the lectin isolated from the marine sponge Aplysina lactuta (ALL). ALL is a homotetramer of 60 kDa formed by four 15 kDa-subunits. The lectin showed affinity only for the glycoproteins fetuin, asialofetuin, mucin type III, and bovine submaxillary mucin type I. The complete amino acid sequences of two isoforms of ALL, named ALL-a and ALL-b, were determined by a combination of Edman degradation and overlapped peptides sequenced by tandem mass spectrometry. ALL-a and ALL-b have 144 amino acids with molecular masses of 15,736 Da and 15,985 Da, respectively. Both structures contain conserved residues typical of the galectin family. ALL is a protein with antibacterial potential, when in association with ampicillin and oxacillin the lectin potentiates its antibiotic effect, included Methicillin-resistant Staphylococcus strains. Thus, ALL shows to be a molecule with potential for the development of new antibacterial drugs.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Poríferos , Animais , Bovinos , Antibacterianos/farmacologia , Antibacterianos/química , Galectinas , OxacilinaRESUMO
The SfL-1 isoform from the marine red algae Solieria filiformis was produced in recombinant form (rSfL-1) and showed hemagglutinating activity and inhibition similar to native SfL. The analysis of circular dichroism revealed the predominance of ß-strands structures with spectra of ßI-proteins for both lectins, which had Melting Temperature (Tm) between 41 °C and 53 °C. The three-dimensional structure of the rSfL-1 was determined by X-ray crystallography, revealing that it is composed of two ß-barrel domains formed by five antiparallel ß chains linked by a short peptide between the ß-barrels. SfL and rSfL-1 were able to agglutinate strains of Escherichia coli and Staphylococcus aureus and did not show antibacterial activity. However, SfL induced a reduction in E. coli biomass at concentrations from 250 to 125 µg mL-1, whereas rSfL-1 induced reduction in all concentrations tested. Additionally, rSfL-1 at concentrations from 250 to 62.5 µg mL-1, showed a statistically significant reduction in the number of colony-forming units, which was not noticed for SfL. Wound healing assay showed that the treatments with SfL and rSfL-1 act in reducing the inflammatory response and in the activation and proliferation of fibroblasts by a larger and fast deposition of collagen.
Assuntos
Lectinas , Rodófitas , Lectinas/farmacologia , Lectinas/química , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química , Rodófitas/química , CicatrizaçãoRESUMO
Antimicrobial resistance is a natural phenomenon and is becoming a huge global public health problem, since some microorganisms not respond to the treatment of several classes of antibiotics. The objective of the present study was to evaluate the antibacterial, antibiofilm, and synergistic effect of triterpene 3ß,6ß,16ß-trihydroxyilup-20(29)-ene (CLF1) against Staphylococcus aureus and Staphylococcus epidermidis strains. Bacterial susceptibility to CLF1 was evaluated by minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assay. In addition, the effect combined with antibiotics (ampicillin and tetracycline) was verified by the checkerboard method. The biofilms susceptibility was assessed by enumeration of colony-forming units (CFUs) and quantification of total biomass by crystal violet staining. The compound showed bacteriostatic and bactericidal activity against all Staphylococcal strains tested. The synergistic effect with ampicillin was observed only for S. epidermidis strains. Moreover, CLF1 significantly inhibited the biofilm formation and disrupted preformed biofilm of the all strains. Scanning electron microscopy (SEM) images showed changes in the cell morphology and structure of S. aureus ATCC 700698 biofilms (a methicillin-resistant S. aureus strain). Molecular docking simulations showed that CLF1 has a more favorable interaction energy than the antibiotic ampicillin on penicillin-binding protein (PBP) 2a of MRSA, coupled in different regions of the protein. Based on the results obtained, CLF1 proved to be a promising antimicrobial compound against Staphylococcus biofilms.
Assuntos
Combretum , Staphylococcus aureus Resistente à Meticilina , Triterpenos , Staphylococcus aureus , Combretum/química , Staphylococcus , Triterpenos/farmacologia , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Ampicilina/farmacologia , Biofilmes , Staphylococcus epidermidis , Testes de Sensibilidade MicrobianaRESUMO
This study investigated the chemical composition and evaluated the antibacterial and antibiofilm activities of essential oils (EOs) extracted from Ruellia asperula (EORA) and Ruellia paniculata (EORP) against oral streptococci. The EO constituents were analyzed by gas chromatography/mass spectrometry. The antimicrobial potential of EOs was evaluated using the minimum inhibitory concentration, minimum bactericidal concentration, and time-kill determination. Furthermore, the quantification of total biomass and the number of viable cells in the biofilms were evaluated. The major constituents of EORA were cariophylla-4(12)-8-(13)-dien-5ß-ol (14.1%), (ß)-caryophyllene (22.7%), and caryophyllene oxide (29.4%). For EORP, the major constituents were (ß)-caryophyllene (11.0%), spathulenol (13.1%), and δ-amorphene (14.9%). The tested EOs exhibited antibacterial activity against planktonic growth and biofilm formation. Thus, the EOs from R. asperula and R. paniculata prove to be promising alternatives for bacterial growth control and biofilm formation prevention of oral streptococci.
Assuntos
Acanthaceae , Anti-Infecciosos , Óleos Voláteis , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade MicrobianaRESUMO
Fibrinogen-related proteins (FREPs) have been identified in several animals. They are involved in the body's defense, acting as mediators of phagocytosis. Ficolins and intelectins are some of the most studied Fibrinogen-related Domain (FReD)-containing lectins. In this work, we have isolated a singular FReD-containing lectin, which cannot be classified as ficolin or intelectin. ELL (Echinometra lucunter lectin) was isolated from coelomic plasma by affinity chromatography on xanthan gum. Primary structure was determined by tandem mass spectrometry. Moreover, antimicrobial activity of ELL was evaluated against planktonic cells and biofilm of Escherichia coli, Staphylococcus aureus and S. epidermidis. ELL showed hemagglutinating activity in Ca2+ presence, which was inhibited by glycoprotein mucin and thyroglobulin. Complete amino acid sequence consisted of 229 residues, including a FReD in the N-terminal. Searches for similarity found that ELL was very close to putative proteins from Strongylocentrotus purpuratus. ELL showed moderate similarity with uncharacterized sea stars proteins and protochordate intelectins. ELL was able to inhibit the planktonic growth of the Gram-positive bacteria and significantly reduce the biofilm formation of all bacteria tested. In conclusion, we identified a new type of FReP-containing lectin with some structural and functional conservation towards intelectins.
Assuntos
Equinodermos , Fibrinogênio , Animais , Equinodermos/metabolismo , Fibrinogênio/genética , Alinhamento de Sequência , Lectinas/genética , Lectinas/farmacologia , Lectinas/metabolismo , Staphylococcus aureus/metabolismo , Escherichia coliRESUMO
This study aims to evaluate the wound healing potential of lectin isolated from the seeds of Centrolobium microchaete (Mart. ex Benth) (CML) on cutaneous wounds in mice. CML did not show cytotoxicity on murine dermal fibroblasts (L929 cell line). The wounds treated with CML (200 µg/mL) showed a decrease in area within 12 days post-operative (P.O.) when compared to control. On 3rd and 7th day P.O., the CML-treated group exhibited fibroblast proliferation and neovascularization. On 12th day P.O., complete restructuring of the epithelial layer and connective tissue was observed in the CML-treated group, whereas control groups exhibited incomplete reepithelialization. CML treatment enhanced the wound closure via the wound contraction process, resulting in the restructuring of the skin layers on 12th day P.O. In conclusion, CML induced a fast and efficient wound healing, suggesting that it can be used as a promising therapeutic tool to heal acute wounds.