RESUMO
Croton heliotropiifolius Kunth, popularly known as "velame," is a shrub that resides in northeastern Brazil. The essential oil of C. heliotropiifolius contains high concentrations of volatile compounds in the leaves and is widely used in folk medicine for many purposes as an antiseptic, analgesic, sedative, and anti-inflammatory agent. Due to the apparent limited amount of information, the aim of this study was to determine the cytotoxic potential of essential oil extracted from leaves of C. heliotropiifolius, utilizing different human cancer cell lines (HL-60, leukemia; HCT-116, colon; MDA-MB435, melanoma; SF295, glioblastoma) and comparison to murine fibroblast L929 cell line. The chemical characterization of the essential oil revealed the presence of large amounts of monoterpenes and sesquiterpenes, the majority of which were aristolene (22.43%), germacrene D (11.38%), ɣ-terpinene (10.85%), and limonene (10.21%). The essential oil exerted significant cytotoxicity on all cancer cells, with low activity on murine L929 fibroblasts, independent of disruption of cell membranes evidenced by absence of hemolytic activity. The cytotoxicity identified was associated with oxidative stress, which culminated in mitochondrial respiration dysfunction and direct or indirect DNA damage (strand breaks and oxidative damage), triggering cell death via apoptosis. Our findings suggest that extracts of essential oil of C. Heliotropiifolius may be considered as agents to be used therapeutically in treatment of certain cancers.
Assuntos
Antineoplásicos , Croton , Óleos Voláteis , Sesquiterpenos , Humanos , Animais , Camundongos , Óleos Voláteis/farmacologia , Croton/química , Linhagem Celular Tumoral , Sesquiterpenos/análise , Folhas de Planta/químicaRESUMO
Tithonia diversifolia is a perennial bushy plant found in South America with significant ethnopharmacological importance as an antimalarial, antidiabetic, antibacterial, and anticancer agent. The aim of the present study was to determine the cytotoxicity of the ethanolic extract from leaves of T. diversifolia (TdE) on human cancer cell lines (HCT-116, SNB-19, NCIH-460 and MCF-7), as well as the mechanism of action involved in cell death and cellular modulation of oxidative stress. The TdE exhibited significant activity with IC50 values ranging from 7.12 to 38.41 µg/ml, with HCT-116 being the most sensitive cell line. Subsequent experiments were conducted with HCT-116 cell line. TdE decreased the number of viable cells, followed by induction of apoptotic events, increase in mitochondrial membrane permeabilization, and enhanced G2/M phase of the cell cycle. Pro-oxidative effects including elevated acidic vesicular organelle formation, lipid peroxidation, and nitric oxide by-products, as well as reduced levels of intracellular glutathione and reactive oxygen species production were also observed following incubation with TdE, which may lead to DNA damage followed by apoptotic cell death. These results demonstrate the potential of TdE ethanolic leaf extraction for biological activity and enhance the importance of continuing to study natural sources of plants for the development of anticancer agents.
Assuntos
Antineoplásicos , Tithonia , Humanos , Extratos Vegetais/farmacologia , Células HCT116 , Estresse Oxidativo , Apoptose , Espécies Reativas de Oxigênio/metabolismo , Etanol , Antineoplásicos/farmacologia , Folhas de PlantaRESUMO
Colorectal carcinogenesis is characterized by oxidative stress and the formation of aberrant crypts in its initial stages. Gum arabic (GA) is a natural product with antioxidant properties, and, therefore, supposed antitumor action. The aim of this study was to evaluate the effects of GA on the formation of aberrant crypts, as well as the local, hepatic, and systemic genotoxicity and oxidative stress. We induced colorectal carcinogenesis in Swiss male mice, afterwards treated them with water, 2.5% GA or 5% GA via gavage for twelve weeks and then performed surgery in order to obtain samples to analysis (proximal and distal colon, liver, blood, and bone marrow). The number of aberrant crypts in the GA-treated animals was lower than in the control groups. Likewise, there was a decline of colonic, hepatic, and systemic genotoxicity and oxidative stress. These results reflect the antioxidant role of GA and may lead to the development of treatments that inhibit colorectal carcinogenesis.
Assuntos
Antioxidantes , Neoplasias Colorretais , Animais , Antioxidantes/farmacologia , Medula Óssea , Carcinogênese , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Goma Arábica/farmacologia , Mucosa Intestinal , Fígado , Masculino , CamundongosRESUMO
Staphylococcus aureus is a commensal bacterium and opportunistic human pathogen that can cause a wide variety of clinical infections. It is recognized for its ability to acquire antimicrobial resistance, so methicillin-resistant Staphylococcus aureus (MRSA) infections are a global healthcare challenge. Therefore, the development of new therapeutic options and alternative therapies for treatment is necessary. Curcumin, a polyphenolic substance found in the rhizome of turmeric longa L, has been shown to have several therapeutic properties, including antimicrobial activity. The objective of the study was to evaluate the in vitro antibacterial activity of curcumin alone and associated with oxacillin against MRSA strains, to analyze the mechanism of cell death involved in the isolated action of curcumin by means of flow cytometry and molecular docking, and to verify its superbiofilm action. Curcumin showed antibacterial activity in the range of 125-500 µg/mL against the tested strains, since it caused an increase in membrane permeability and DNA fragmentation, as revealed by flow cytometry analysis. Moreover, it was possible to observe interactions of curcumin with wild-type S. aureus DHFR, S. aureus gyrase and S. aureus gyrase complex with DNA, DNA (5'-D(*CP*GP*AP*TP*GP*CP*G)-3') and Acyl-PBP2a from MRSA by molecular docking. Curcumin also had a synergistic and additive effect when associated with oxacillin, and significantly reduced the cell viability of the analyzed biofilms. Thus, curcumin is a possible candidate for pharmaceutical formulation development for the treatment of MRSA infections.
Assuntos
Curcumina , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Biofilmes , Curcumina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Plâncton , Staphylococcus aureusRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main human pathogens and is responsible for many diseases, ranging from skin infections to more invasive infections. These infections are dangerous and expensive to treat because these strains are resistant to a large number of conventional antibiotics. Thus, the antibacterial effect of ketamine against MRSA strains, its mechanism of action, and in silico interaction with sortase A were evaluated. The antibacterial effect of ketamine was assessed using the broth microdilution method. Subsequently, the mechanism of action was assessed using flow cytometry and molecular docking assays with sortase A. Our results showed that ketamine has a significant antibacterial activity against MRSA strains in the range of 2.49-3.73 mM. Their mechanism of action involves alterations in membrane integrity and DNA damage, reducing cell viability, and inducing apoptosis. In addition, ketamine had an affinity for S. aureus sortase A. These results indicate that this compound can be used as an alternative to develop new strategies to combat infections caused by MRSA.
Assuntos
Ketamina , Staphylococcus aureus Resistente à Meticilina , Aminoaciltransferases , Antibacterianos/farmacologia , Proteínas de Bactérias , Cisteína Endopeptidases , Humanos , Ketamina/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Staphylococcus aureusRESUMO
Oncocalyxone A, a 1,4-benzoquinone derived from Cordia oncocalyx, exhibits anti-inflammatory, antimicrobial and antidiabetic properties. The aim of this study was to (1) examine the cytotoxic actions of oncocalyxone A on human normal and tumor cell lines and (2) determine mechanistic actions underlying effects upon leukemia cells using cellular and molecular techniques. Antiproliferative studies on cancer cell lines, peripheral blood mononuclear cells, and human erythrocytes were performed using colorimetric assays. To understand cytotoxicity, assessments were performed with HL-60 leukemia cells (8, 16.5, or 33 µM) after 24 hr incubation using light and fluorescence microscopy, trypan blue, flow cytometry, Comet assay, western blot of caspases and poly-ADP-ribose polymerase (PARP), and effects on topoisomerase I and II. Oncocalyxone A exhibited cytotoxic action upon HL-60 cells and dividing leukocytes, but minimal hemolytic action on erythrocytes. Mechanistic investigations demonstrated reduction of cell viability, loss of membrane integrity, cell shrinking, chromatin condensation, blebbings, externalization of phosphatidylserine, caspase activation, PARP cleavage, mitochondrial depolarization, and DNA damage. Pre-treatment with N-acetylcysteine 4 mM significantly reduced DNA damage and prevented membrane integrity loss. Oncocalyxone A displayed free radical dependent antileukemic activity via apoptotic pathways and induced DNA damage in HL-60 cells. Oncocalyxone A possesses structural chemical simplicity enabling it to be a cost-effective alternative. These properties justify further improvements to enhance activity and selectivity and the development of pharmaceutical formulations. Abbreviations Acridine orange, AO; ANOVA, analysis of variance; BSA, bovine serum albumin; DI, Damage Index; DMSO, dimethylsulfoxide; EC50, effective concentration 50%; EDTA, ethylenediamine tetraacetic acid; EB, ethidium bromide; HCT-116, colon carcinoma line; HL-60, promyelocytic leukemia line; IC50, inhibitory concentration 50%; MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; OVCAR-8, ovarian carcinoma line; NAC, N-acetylcysteine, PBMC, peripheral blood mononuclear cells; PBS, phosphate-buffered saline; PI, propidium iodide; PARP, poly-ADP-ribose polymerase; RPMI-1640, Roswell Park Memorial Institute medium; SF-295, glioblastoma line; ROS, reactive oxygen species; 7-AAD, 7-amino-actinomycin D; H2-DCF-DA, 7'-dichlorodihydrofluorescein diacetate.
Assuntos
Antraquinonas/farmacologia , Antineoplásicos/farmacologia , Antraquinonas/química , Antineoplásicos/química , Células HL-60 , HumanosRESUMO
Troxerutin is a natural flavonoid present abundantly in tea, coffee, olives, wheat, and a variety of fruits and vegetables. Due to its diverse pharmacological properties, this flavonoid has aroused interest for treatment of various diseases, and consequently prompted investigation into its toxicological characteristics. The aim of this study was to evaluate the genotoxic and mutagenic effects and chemoprotective activity attributed to troxerutin using human peripheral blood leukocytes (PBLs) through several well-established experimental protocols based upon different parameters. Data demonstrated that troxerutin (100 to 1000 µM) induced no marked cytotoxic effect on PBLs after 24 hr, and did not produce strand breaks and mutagenicity. Regarding chemoprevention, this flavonoid attenuated cytotoxicity, genotoxicity, and mutagenicity initiated by hydrogen peroxide (H2O2) in human PBLs. Further, troxerutin demonstrated no marked cytotoxic effect on PBLs and exerted a protective effect against oxidative stress induced by H2O2 through modulation of GSH-dependent enzymes.
Assuntos
Glutationa/metabolismo , Peróxido de Hidrogênio/farmacologia , Hidroxietilrutosídeo/análogos & derivados , Leucócitos/fisiologia , Oxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Anticoagulantes/farmacologia , Humanos , Hidroxietilrutosídeo/farmacologia , Leucócitos/efeitos dos fármacos , Leucócitos/enzimologiaRESUMO
Coronavirus (COVID-19) is an enveloped RNA virus that is diversely found in humans and that has now been declared a global pandemic by the World Health Organization. Thus, there is an urgent need to develop effective therapies and vaccines against this disease. In this context, this study aimed to evaluate in silico the molecular interactions of drugs with therapeutic indications for treatment of COVID-19 (Azithromycin, Baricitinib and Hydroxychloroquine) and drugs with similar structures (Chloroquine, Quinacrine and Ruxolitinib) in docking models from the SARS-CoV-2 main protease (M-pro) protein. The results showed that all inhibitors bound to the same enzyme site, more specifically in domain III of the SARS-CoV-2 main protease. Therefore, this study allows proposing the use of baricitinib and quinacrine, in combination with azithromycin; however, these computer simulations are just an initial step for conceiving new projects for the development of antiviral molecules.
Assuntos
Antivirais/química , Antivirais/farmacologia , COVID-19/virologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/química , SARS-CoV-2/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Cisteína Endopeptidases/química , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Simulação de Acoplamento Molecular , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , SARS-CoV-2/enzimologia , Tratamento Farmacológico da COVID-19RESUMO
Emergence of methicilin resistant Staphylococcus aureus (MRSA) strains is a major cause of infirmity worldwide and has limited our therapeutic options against these pathogens. In this regard, the search for candidates with an antimicrobial activity, with a greater efficacy and a lower toxicity, is necessary. As a result, there is greater need to search for resistance modifying agents which, in combination with existing drugs, will restore the efficacy of these drugs. The antibacterial effect of fluoxetine was determined by a broth microdilution method (the M07-A9 method of the Clinical and Laboratory Standard Institute) and flow cytometry techniques in which the probable mechanism of action of the compound was also assessed. The isolates used in the study belonged to the Laboratory of Bioprospecting of Antimicrobial Molecules (LABIMAN) of the Federal University of Ceará. After 24â¯h, Methicillin-resistant Sthaphylococcus aureus (MRSA) strains showed fluoxetine MICs equal to 64⯵g/mL and 128⯵g/mL, respectively. Cytometric analysis showed that treatment with fluoxetine caused alterations to the integrity of the plasma membranes and DNA damage, which led to cell death, probably by apoptosis.
Assuntos
Antibacterianos/farmacologia , Fluoxetina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Dano ao DNA , Citometria de Fluxo , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacosRESUMO
The increased incidence of candidemia in terciary hospitals worldwide and the cross-resistance frequency require the new therapeutic strategies development. Recently, our research group demonstrated three semi-synthetic naphthofuranquinones (NFQs) with a significant antifungal activity in a fluconazole-resistant (FLC) C. tropicalis strain. The current study aimed to investigate the action's preliminary mechanisms of NFQs by several standardized methods such as proteomic and flow cytometry analyzes, comet assay, immunohistochemistry and confocal microscopy evaluation. Our data showed C. tropicalis 24 h treated with all NFQs induced an expression's increase of proteins involved in the metabolic response to stress, energy metabolism, glycolysis, nucleosome assembly and translation process. Some aspects of proteomic analysis are in consonance with our flow cytometry analysis which indicated an augmentation of intracellular ROS, mitochondrial dysfunction and DNA strand breaks (neutral comet assay and γ-H2AX detection). In conclusion, our data highlights the great contribution of ROS as a key event, probably not the one, associated to anti-candida properties of studied NFQs.
Assuntos
Antifúngicos/farmacologia , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/metabolismo , Farmacorresistência Fúngica/efeitos dos fármacos , Farmacorresistência Fúngica/fisiologia , Naftoquinonas/farmacologia , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Antifúngicos/síntese química , Antifúngicos/química , Candida tropicalis/genética , Candidemia/microbiologia , Ciclo Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Fúngico/genética , Metabolismo Energético/efeitos dos fármacos , Fluconazol/farmacologia , Glicólise/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mitocôndrias/efeitos dos fármacos , Naftoquinonas/síntese química , Naftoquinonas/química , Estresse PsicológicoRESUMO
Recent research has shown broad antifungal activity of the classic antidepressants selective serotonin reuptake inhibitors (SSRIs). This fact, combined with the increased cross-resistance frequency of the genre Candida regarding the main treatment today, fluconazole, requires the development of novel therapeutic strategies. In that context, this study aimed to assess the antifungal potential of fluoxetine, sertraline, and paroxetine against fluconazole-resistant Candida spp. planktonic cells, as well as to assess the mechanism of action and the viability of biofilms treated with fluoxetine. After 24 h, the fluconazole-resistant Candida spp. strains showed minimum inhibitory concentration (MIC) in the ranges of 20-160 µg/mL for fluoxetine, 10-20 µg/mL for sertraline, and 10-100.8 µg/mL for paroxetine by the broth microdilution method (M27-A3). According to our data by flow cytometry, each of the SSRIs cause fungal death after damaging the plasma and mitochondrial membrane, which activates apoptotic signaling pathways and leads to dose-dependant cell viability loss. Regarding biofilm-forming isolates, the fluoxetine reduce mature biofilm of all the species tested. Therefore, it is concluded that SSRIs are capable of inhibit the growth in vitro of Candida spp., both in planktonic form, as biofilm, inducing cellular death by apoptosis.
Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida/citologia , Candida/genética , Candida/crescimento & desenvolvimento , Contagem de Células , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Fúngico/efeitos dos fármacos , Fibroblastos/microbiologia , Citometria de Fluxo , Técnicas In Vitro , Potenciais da Membrana , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Membranas Mitocondriais/efeitos dos fármacos , Paroxetina/farmacologia , Plasma/efeitos dos fármacos , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Sertralina/farmacologiaRESUMO
CONTEXT: Propolis has promising biological activities. Propolis samples from the Northeast of Bahia, Brazil - sample A from Ribeira do Pombal and B, from Tucano - were investigated, with new information regarding their biological activities. OBJECTIVE: This paper describes the chemical profile, antioxidant, anti-glycation and cytotoxic activities of these propolis samples. MATERIAL AND METHODS: Ethanol extracts of these propolis samples (EEP) and their fractions were analyzed to determine total phenolic content (TPC); antioxidant capacity through DPPHâ¢, FRAP and lipid peroxidation; anti-glycation activity, by an in vitro glucose (10 mg/mL) bovine serum albumine (1 mg/mL) assay, during 7 d; cytotoxic activity on cancer (SF295, HCT-116, OVCAR-8, MDA-MB435, MX-1, MCF7, HL60, JURKAT, MOLT-4, K562, PC3, DU145) and normal cell lines (V79) at 0.04-25 µg/mL concentrations, for 72 h. The determination of primary phenols by ultra high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and volatile organic compounds content by gas chromatography-mass spectrometry (GC-MS) were also performed. RESULTS: The EEP polar fractions exhibited up to 90% protection against lipid peroxidation. The IC50 value for anti-glycation activity of EEP was between 16.5 and 19.2 µg/mL, close to aminoguanidine (IC50 = 7.7 µg/mL). The use of UHPLC-MS/MS and GC-MS allowed the identification of 12 bioactive phenols in the EEP and 24 volatile compounds, all already reported. CONCLUSIONS: The samples present good antioxidant/anti-glycation/cytotoxic activities and a plethora of biologically active compounds. These results suggest a potential role of propolis in targeting ageing and diseases associated with oxidative and carbonylic stress, aggregating value to them.
Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Descoberta de Drogas , Hipoglicemiantes/farmacologia , Polifenóis/farmacologia , Própole/química , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antioxidantes/efeitos adversos , Antioxidantes/química , Antioxidantes/isolamento & purificação , Produtos Biológicos/efeitos adversos , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Brasil , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cricetinae , Cricetulus , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Peroxidação de Lipídeos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Estrutura Molecular , Polifenóis/efeitos adversos , Polifenóis/química , Polifenóis/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
The incidence of fungal infections and, in particular, the incidence of fungal antibiotic resistance, which is associated with biofilm formation, have significantly increased, contributing to morbidity and mortality. Thus, new therapeutic strategies need to be developed. In this context, natural products have emerged as a major source of possible antifungal agents. Berberine is a protoberberine-type isoquinoline alkaloid isolated from the roots, rhizomes, and stem bark of natural herbs, such as Berberis aquifolium, Berberis vulgaris, Berberis aristata, and Hydrastis canadensis, and of Phellodendron amurense Berberine has been proven to have broad antibacterial and antifungal activity. In the present study, the potential antifungal effect of berberine against fluconazole-resistant Candida and Cryptococcus neoformans strains, as well as against the biofilm form of Candida spp., was assessed. The antifungal effect of berberine was determined by a broth microdilution method (the M27-A3 method of the Clinical and Laboratory Standards Institute) and flow cytometry techniques, in which the probable mechanism of action of the compound was also assessed. For biofilm assessment, a colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine the susceptibility of sessile cells. The isolates used in the study belonged to the Laboratory of Bioprospection and Experiments in Yeast (LABEL) of the Federal University of Ceará. After 24 and 72 h, fluconazole-resistant Candida and Cryptococcus neoformans strains showed berberine MICs equal to 8 µg/ml and 16 µg/ml, respectively. Cytometric analysis showed that treatment with berberine caused alterations to the integrity of the plasma and mitochondrial membranes and DNA damage, which led to cell death, probably by apoptosis. Assessment of biofilm-forming isolates after treatment showed statistically significant reductions in biofilm cell activity (P < 0.001).
Assuntos
Antifúngicos/farmacologia , Berberina/farmacologia , Candida/efeitos dos fármacos , Candidíase/tratamento farmacológico , Criptococose/tratamento farmacológico , Cryptococcus neoformans/efeitos dos fármacos , Fluconazol/farmacologia , Animais , Berberina/efeitos adversos , Biofilmes/crescimento & desenvolvimento , Candida/classificação , Candida/genética , Candidíase/microbiologia , Linhagem Celular , Proliferação de Células , Criptococose/microbiologia , Cryptococcus neoformans/classificação , Cryptococcus neoformans/genética , DNA Fúngico/genética , Farmacorresistência Fúngica , Fluconazol/efeitos adversos , Humanos , Células L , Camundongos , Testes de Sensibilidade Microbiana , Membranas Mitocondriais/efeitos dos fármacos , Tipagem Molecular , Técnicas de Tipagem MicológicaRESUMO
Endophytic actinobacteria from the Brazilian medicinal plant Lychnophora ericoides were isolated for the first time, and the biological potential of their secondary metabolites was evaluated. A phylogenic analysis of isolated actinobacteria was accomplished with 16S rRNA gene sequencing, and the predominance of the genus Streptomyces was observed. All strains were cultured on solid rice medium, and ethanol extracts were evaluated with antimicrobial and cytotoxic assays against cancer cell lines. As a result, 92% of the extracts showed a high or moderate activity against at least one pathogenic microbial strain or cancer cell line. Based on the biological and chemical analyses of crude extracts, three endophytic strains were selected for further investigation of their chemical profiles. Sixteen compounds were isolated, and 3-hydroxy-4-methoxybenzamide (9) and 2,3-dihydro-2,2-dimethyl-4(1H)-quinazolinone (15) are reported as natural products for the first time in this study. The biological activity of the pure compounds was also assessed. Compound 15 displayed potent cytotoxic activity against all four tested cancer cell lines. Nocardamine (2) was only moderately active against two cancer cell lines but showed strong activity against Trypanosoma cruzi. Our results show that endophytic actinobacteria from L. ericoides are a promising source of bioactive compounds.
Assuntos
Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Antiprotozoários/farmacologia , Asteraceae/microbiologia , Produtos Biológicos/farmacologia , Metabolismo Secundário , Actinobacteria/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Brasil , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Plantas Medicinais/microbiologia , Relação Estrutura-Atividade , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Flavonoids are a class of phenolic compounds commonly found in fruits, vegetables, grains, flowers, tea, and wine. They differ in their chemical structures and characteristics. Such compounds show various biological functions and have antioxidant, antimicrobial, anti-inflammatory, and antiapoptotic properties. The aim of this study was to evaluate the in vitro interactions of flavonoids with fluconazole against Candida tropicalis strains resistant to fluconazole, investigating the mechanism of synergism. Three combinations formed by the flavonoids (+)-catechin hydrated, hydrated quercetin, and (-)-epigallocatechin gallate at a fixed concentration with fluconazole were tested. Flavonoids alone had no antifungal activity within the concentration range tested, but when they were used as a cotreatment with fluconazole, there was significant synergistic activity. From this result, we set out to evaluate the possible mechanisms of cell death involved in this synergism. Isolated flavonoids did not induce morphological changes or changes in membrane integrity in the strains tested, but when they were used as a cotreatment with fluconazole, these changes were quite significant. When evaluating mitochondrial damage and the production of reactive oxygen species (ROS) only in the cotreatment, changes were observed. Flavonoids combined with fluconazole were shown to cause a significant increase in the rate of damage and the frequency of DNA damage in the tested strains. The cotreatment also induced an increase in the externalization of phosphatidylserine, an important marker of early apoptosis. It is concluded that flavonoids, when combined with fluconazole, show activity against strains of C. tropicalis resistant to fluconazole, promoting apoptosis by exposure of phosphatidylserine in the plasma membrane and morphological changes, mitochondrial depolarization, intracellular accumulation of ROS, condensation, and DNA fragmentation.
Assuntos
Antifúngicos/farmacologia , Apoptose/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/farmacologia , Fluconazol/farmacologia , Quercetina/farmacologia , Antifúngicos/administração & dosagem , Interações Medicamentosas , Farmacorresistência Fúngica/efeitos dos fármacos , Sinergismo Farmacológico , Fluconazol/administração & dosagem , Testes de Sensibilidade Microbiana , Espécies Reativas de Oxigênio/metabolismoRESUMO
Aim: The present study investigated the antimicrobial effectiveness of a rhamnolipid complexed with arginine (RLMIX_Arg) against planktonic cells and biofilms of methicillin-resistant Staphylococcus aureus (MRSA). Methodology: Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol: M07-A10, checkerboard test, biofilm in plates and catheters and flow cytometry were used. Result: RLMIX_Arg has bactericidal and synergistic activity with oxacillin. RLMIX_Arg inhibits the formation of MRSA biofilms on plates at sub-inhibitory concentrations and has antibiofilm action against MRSA in peripheral venous catheters. Catheters impregnated with RLMIX_Arg reduce the formation of MRSA biofilms. Conclusion: RLMIX_Arg exhibits potential for application in preventing infections related to methicillin-resistant S. aureus biofilms.
[Box: see text].
Assuntos
Antibacterianos , Arginina , Biofilmes , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Tensoativos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Arginina/farmacologia , Arginina/química , Antibacterianos/farmacologia , Antibacterianos/química , Humanos , Tensoativos/farmacologia , Tensoativos/química , Glicolipídeos/farmacologia , Glicolipídeos/química , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/tratamento farmacológico , Oxacilina/farmacologia , Sinergismo FarmacológicoRESUMO
Aim: Evaluate the anticandidal effect of Croton heliotropiifolius Kunth essential oil and its interaction with azoles and N-acetylcysteine (NAC) against planktonic cells and biofilms. Materials & methods: Broth microdilution and checkerboard methods were used to evaluate the individual and combined activity with fluconazole and itraconazole (ITRA). The antibiofilm effect of the oil was assessed in 96-well plates alone and combined with ITRA and NAC, and cytotoxicity determined by MTT. Results: The oil inhibited all Candida species growth. The activity was enhanced when associated with ITRA and NAC for planktonic cells and biofilms in formation. The effective concentrations were lower than the toxic ones to V79 cells. Conclusion: C. heliotropiifolius Kunth essential oil is an anticandidal alternative, and can be associated with ITRA and NAC.
Candida is a type of fungus that can cause disease in people. In recent years, the number of available drugs to treat this disease have declined. It is important to search for new drugs. Plants are often used to improve health, so we tested the essential oil of a plant called Croton heliotropiifolius to see if it could kill the fungus. We found that the essential oil could kill the fungus, and could be used with other drugs to improve their effects.
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Candida species are among the priority pathogens in the area of research and development. Due to the problems associated with resistance to antifungals, new therapeutic alternatives are necessary. In this regard, drug repositioning has gained prominence. The objective of this study was to evaluate the activity of three tricyclic antidepressants (TCAs) - amitriptyline (AMT), nortriptyline (NOR) and clomipramine (CLO) - isolated or associated with antifungals against strains of Candida spp., as well as to analyze the possible mechanism of action. Among the methods used were broth microdilution tests, tolerance level assessment, checkerboard assays, flow cytometry and fluorescence microscopy. Furthermore, Candida cells were visualized after treatments by scanning electron microscopy (SEM). AMT presented MIC 50% in the range of 16 to 128 µg/mL, NOR from 8 to 128 µg/mL, and CLO from 8 to 64 µg/mL, with all three TCAs having a fungicidal inhibitory action profile. For these TCAs, there was synergism with amphotericin B (AMB) in 100% of the isolates. In association with fluconazole (FLC) and itraconazole (ITR), there were mostly indifferent interactions. TCAs isolated and associated with AMB reduced cell viability, promoted DNA fragmentation and damage, caused mitochondrial depolarization, externalization of phosphatidylserine, produced reactive oxygen species (ROS), decreased reduced glutathione (GSH) and increased carbonyl protein levels, causing morphological changes. The results suggest the antifungal mechanism of the TCAs works via the apoptotic pathway.
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The increase in fungal resistance is a major public health concern. In this context, Candida spp. is an important genus related to invasive diseases, especially in immunosuppressed patients. The relevance of alternative approaches to increasing fungal resistance stands out, in which products of natural origin demonstrate potential antifungal activity in vitro against Candida spp. In this sense, this work aimed to evaluate the in vitro activity of tannic acid against Candida spp. Minimum inhibitory concentration (MIC) was determined for tannic acid and the antifungals, and the checkerboard assay was performed to analyze the interactions between them. Furthermore, we evaluated the tannic acid antibiofilm activity and its possible mechanism of action. Tannic acid showed MIC ranging to 0.06 to 0.5 µg/ml and showed no loss of effectiveness when combined with antifungals. Also, is safe at the concentrations it exerts its antifungal activity in pre-formed biofilms, as demonstrated by IC50 in murine fibroblasts cells and the hemolytic assay. Additionally, its mechanisms of action can be related with induction of signals that lead to apoptosis in fungal cells.
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Aim: To evaluate the antifungal activity of mangiferin against Candida spp. resistant to fluconazole.Materials & methods: The antifungal activity of mangiferin was assessed using broth microdilution and its interaction with azoles and amphotericin B was evaluated by checkerboard. The activity of mangiferin against Candida spp. biofilms was assessed using the MTT colorimetric assay and its possible mechanism of action was evaluated using flow cytometry.Results: Mangiferin showed activity against Candida albicans, Candida tropicalis and Candida parapsilosis resistant to fluconazole and showed synergism with azoles and amphotericin B. Mangiferin increased the activity of antifungals against Candida biofilms and caused depolarization of the mitochondrial membrane and externalization of phosphatidylserine, suggesting apoptosis.Conclusion: mangiferin combined with antifungals has potential against Candida spp.
Candida is a type of fungus that can make people ill. Over time, many species of Candida have found ways to resist the drugs used to kill them. It is important to find new drugs. We decided to see if a substance called mangiferin works against Candida. We found that mangiferin works against Candida and may help other drugs to work better. We still need to do more studies to find out whether mangiferin can help prevent diseases caused by Candida in the future.