RESUMO
This manuscript presents a new report on the in vitro antimicrobial photo-inactivation of foodborne microorganisms (Salmonella spp. and Listeria monocytogenes) using tetra-cationic porphyrins. Isomeric tetra-cationic porphyrins (3MeTPyP, 4MeTPyP, 3PtTPyP, and 4PtTPyP) were tested, and antimicrobial activity assays were performed at specific photosensitizer concentrations under dark and white-light LED irradiation conditions. Among the tested bacterial strains, 4MeTPyP exhibited the highest efficiency, inhibiting bacterial growth within just 60 min at low concentrations (17.5 µM). The minimal inhibitory concentration of 4MeTPyP increased when reactive oxygen species scavengers were present, indicating the significant involvement of singlet oxygen species in the photooxidation mechanism. Furthermore, the checkerboard assay testing the association of 4MeTPyP showed an indifferent effect. Atomic force microscopy analyses and dynamic simulations were conducted to enhance our understanding of the interaction between this porphyrin and the strain's membrane.
Assuntos
Biofilmes , Listeria monocytogenes , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Fármacos Fotossensibilizantes , Porfirinas , Porfirinas/farmacologia , Porfirinas/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Biofilmes/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Microbiologia de Alimentos , Antibacterianos/farmacologia , Antibacterianos/química , Microscopia de Força Atômica , Espécies Reativas de Oxigênio/metabolismo , Luz , Oxigênio Singlete/metabolismo , Oxigênio Singlete/químicaRESUMO
Microbial infections caused by sessile microorganisms are known to be a more challenging issue than infections caused by the same microorganisms in the planktonic state. Pseudomonas aeruginosa is an opportunistic pathogen and biofilm-forming agent. This species presents intense cellular communication mediated by signaling molecules. This process is known as quorum sensing (QS) and induces the transcription of specific genes that favors cell density growth and three-dimensional bacterial grouping. In this context, the discovery of compounds capable of inhibiting the action of the QS signaling molecules seems to be a promising strategy against biofilms. This work aimed to evaluate the anti-biofilm action and the in vitro safety profile of a sulfamethoxazole-Ag complex. The results obtained indicate potential anti-biofilm activity through QS inhibition. In silico tests showed that the compound acts on the las and pqs systems, which are the main regulators of biofilm formation in P. aeruginosa. Additionally, the molecule proved to be safe for human peripheral blood mononuclear cells.
Assuntos
Pseudomonas aeruginosa , Percepção de Quorum , Antibacterianos/farmacologia , Biofilmes , Humanos , Leucócitos Mononucleares , Simulação de Acoplamento Molecular , Prata/farmacologia , Sulfonamidas/farmacologia , Fatores de VirulênciaRESUMO
Natural products are still a promising source of bioactive molecules. Food and Drug Administration data showed that approximately 49% of the approved molecules originate naturally or chemically-resemble these substances, of which more than 70% are being used in anticancer therapy. It is noteworthy that at present there are no scientific studies to prove the effectiveness and safety of a number of plants used in folk medicine such as in the case of Calyptranthes grandifolia O. Berg (Myrtaceae) originally from South America. The aim of the present study was to determine the biological potential and toxicological effects of the aqueous leaf extract of C. grandifolia. The main detected phytoconstituents were condensed tannins and flavonoids and a high quantity of polyphenols. Regarding the antimicrobial potential, the extract exerted inhibitory activity against Pseudomonas aeruginosa. The results also revealed the extract induced DNA damage in a concentration-dependent manner in RAW 264.7 cells. In addition, C. grandifolia produced cytotoxicity in leukemia cell lines (HL60 and Kasumi-1) without affecting isolated human lymphocytes but significantly inhibited JAK3 and p38α enzyme activity. Taken together, these findings add important information on the biological and toxicological effects of C. grandifolia, indicating that aqueous extract may be a source of natural antimicrobial and antileukemic constituents.
Assuntos
Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Myrtaceae/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Antibacterianos/química , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Compostos de Bifenilo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Camundongos , Picratos , Extratos Vegetais/química , Pseudomonas aeruginosa/efeitos dos fármacos , Células RAW 264.7RESUMO
Pseudomonas aeruginosa is a ubiquitous microorganism that commonly causes hospital-acquired infections, including pneumonia, bloodstream and urinary tract infections and it is well known for chronically colonising the respiratory tract of patients with cystic fibrosis, causing severe intermittent exacerbation of the condition. P. aeruginosa may appear in the free form cell but also grows in biofilm communities adhered to a surface. An alternative to conventional antimicrobial agents are nanoparticles that can act as carriers for antibiotics and other drugs. In this context, the study aimed to characterise and verify the anti-biofilm potential of GML Nanocapsules against P. aeruginosa. The nanocapsules showed a mean diameter of 190.7â¯nm, polydispersion index of 0.069, the zeta potential of -23.3â¯mV. The microdilution test showed a MIC of 62.5⯵g/mL to GML and 15.62⯵g/mL to GML Nanocapsules. The anti-biofilm experiments demonstrated the significant reduction of biomass, proteins, polysaccharide and viable P. aeruginosa in biofilm treated with GML Nanocapsules while the free GML did not cause an effect. The AFM images showed a decrease in a biofilm which received GML. The positive results suggest an alternative for the public health trouble related to infections associated with biofilm.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Lauratos/farmacologia , Monoglicerídeos/farmacologia , Nanocápsulas , Pseudomonas aeruginosa/efeitos dos fármacos , Tensoativos/farmacologia , Portadores de Fármacos , Testes de Sensibilidade MicrobianaRESUMO
The increase of microbial resistance generates the search for new substances with antimicrobial potential. The essential oil of Cymbopogon flexuosus (Lemongrass) stands out in the literature for its antimicrobial, insecticide and antioxidant properties, but it has high volatilization and low stability, and the nanoencapsulation of this oil could be an alternative to overcome these limitations. Thus, the objective of this study was to develop, for the first time, nanoemulsions containing the essential oil of C. flexuosus, through a method that does not use organic solvent and with temperature control to avoid the volatilization of the oil, characterize and evaluate of stability and the antimicrobial and antibiofilm activities of these nanoemulsions. Nanoemulsions presented adequate physicochemical characteristics (average size less than 200â¯nm, polydispersity index less than 0.3, negative zeta potential and acid pH) which were maintained during 90 days of storage, and the nanoencapsulation of the C. flexuosus oil enhanced its therapeutic efficacy against the microorganisms evaluated in this study compared to the free oil. These results are very promising because among the microorganisms that the nanoemulsion containing C. flexuosus was able to inhibit the formation of biofilm are the bacteria Pseudomonas aeruginosa and Staphylococcus aureus, which were recently listed by the World Health Organization as priority pathogens for development of new antibiotics.
Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Cymbopogon/química , Nanopartículas/química , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antioxidantes , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Óleos Voláteis/química , Tamanho da Partícula , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , TemperaturaRESUMO
This is a systematic review of clinical and laboratory studies evaluating the effect of Melaleuca alternifolia on periodontopathogens, dental plaque, gingivitis, periodontitis, and inflammatory responses. The PubMed, Cochrane, Web of science, Bireme, Lilacs, Prospero, Open Grey, and Clinical Trials databases were searched to identify potentially eligible studies through October 2016. Of 1,654 potentially eligible studies, 25 were included in the systematic review. Their methodology was evaluated through the Cochrane Handbook for clinical studies and the GRADE system for in vivo/in vitro studies. Although clinical studies must be interpreted with caution due to methodological limitations, laboratory studies have found promising results. In vitro evidences showed that M. alternifolia has bactericidal and bacteriostatic effects against the most prevalent periodontopathogens. Clinical studies found comparable effects to chlorhexidine 0.12% in reducing gingival inflammation, although the antiplaque effect was lower. M. alternifolia also showed antioxidant properties, which are beneficial to the host, allied to the reduction on immune-inflammatory responses to pathogens. This systematic review suggests that the M. alternifolia has potential anti-inflammatory and antimicrobial properties, which can be easily applied to the periodontal tissues. However, further clinical trials are needed to elucidate the clinical relevance of its application.
Assuntos
Antibacterianos/uso terapêutico , Placa Dentária/tratamento farmacológico , Melaleuca/química , Doenças Periodontais/tratamento farmacológico , Antibacterianos/farmacologia , HumanosRESUMO
Carya illinoensis is a widespread species, belonging to the Juglandaceae family, commonly known as Pecan. Popularly, the leaves have been used in the treatment of smoking as a hypoglycemic, cleansing, astringent, keratolytic, antioxidant, and antimicrobial agent. The following research aimed to identify for the first time the phytochemical compounds present in the leaves of C. illinoensis and carry out the determination of antimicrobial activity of aqueous and ethanolic extracts. The antimicrobial activity was tested against 20 microorganisms by determining the minimum inhibitory concentration (MIC). Phenolic acids (gallic acid and ellagic acid), flavonoids (rutin), and tannins (catechins and epicatechins) were identified by HPLC-DAD and may be partially responsible for the antimicrobial activity against Gram-positive, Gram-negative, and yeast. The results showed MIC values between 25 mg/mL and 0.78 mg/mL. The extracts were also able to inhibit the production of germ tubes by Candida albicans.
Assuntos
Antifúngicos/análise , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Carya/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Leveduras/efeitos dos fármacos , Antifúngicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Hidroxibenzoatos/análise , Hidroxibenzoatos/isolamento & purificação , Hidroxibenzoatos/farmacologia , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/isolamento & purificação , Folhas de Planta/química , Taninos/análise , Taninos/isolamento & purificação , Taninos/farmacologiaRESUMO
Candida species are the main responsible microorganisms for causing fungal infections worldwide, and Candida albicans is most frequently associated with infectious processes. Pseudomonas aeruginosa is a gram-negative bacterium commonly found in immunocompromised patients. The infection persistence caused by these microorganisms is often related to antimicrobial resistance and biofilm formation. In this context, the objective of the present study was to prepare and characterize nanoemulsions containing Eucalyptus globulus oil and to verify its antimicrobial and antibiofilm activities against P. aeruginosa and Candida spp. The nanoemulsions had a size of approximately 76 nm, a polydispersity index of 0.22, a zeta potential of - 9,42 mV and a pH of approximately 5.0. The E. globulus oil was characterized by gas chromatography, being possible to observe its main components, such as 1-8-Cineol (75.8%), p- Cymene (7.5%), α-Pinene (7.4%) and Limonene (6.4%). The antimicrobial activity of the nanoemulsion was determined from the macrodilution tests and the cell viability curve, where the minimum fungicidal concentration of 0.7 mg/mL for C. albicans and 1.4 mg/mL for C. tropicalis and C. glabrata were obtained. However, the nanoemulsions did not present antimicrobial activity against P. aeruginosa, since it contains only 5% of the oil, being ineffective for this microorganism. The nanoencapsulated oil action against the formed biofilm was evaluated by atomic force microscopy and calcofluor staining, and the nanoemulsion was more efficient for two of the three Candida species when compared to free oil.
Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Eucalyptus/química , Nanopartículas/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Anti-Infecciosos/química , Benzenossulfonatos , Monoterpenos Bicíclicos , Biofilmes/crescimento & desenvolvimento , Cicloexanóis , Cicloexenos , Cimenos , Eucaliptol , Concentração de Íons de Hidrogênio , Limoneno , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Monoterpenos , Nanotecnologia , Óleos Voláteis/administração & dosagem , Tamanho da Partícula , Propriedades de Superfície , TerpenosRESUMO
Rapidly growing mycobacteria (RGM) are opportunistic microorganisms that can cause both local and disseminated infections. When in biofilm, these pathogens become highly resistant to antimicrobials used in clinical practice. Composed abundantly of polymeric substances, biofilms delay the diffusion of antimicrobials, preventing the drug from penetrating the deeper layers and having an effective action. Therefore, the search for new and alternative therapeutic options has become of fundamental importance. Natural products fall into these options, especially essential oils. However, these oils present problems, such as low miscibility in water (which decreases its bioavailability) and degradation by light and temperature. Thus, the objective of this work was to explore the action of free essential oil and nanoemulsions of Cymbopogon flexuosus on strains of RGM, in planktonic and sessile forms. In this work, standard strains of Mycobacterium fortuitum (ATCC 6841), Mycobacterium massiliense (ATCC 48898) and Mycobacterium abscessus (ATCC 19977) were used. The susceptibility of the microorganisms in planktonic form was obtained by conventional microdilution techniques and by cell viability curve. The analysis of the antibiofilm activity was performed by a semi-quantitative macrotechnique. The nanoemulsion exhibited significant antimicrobial activity, with minimum inhibitory concentration values lower than those presented by the free essential oil, against strains in the planktonic state. However, both were efficient in destroying the already formed biofilm, whereas only the free oil inhibited the formation of mycobacterial biofilm. This study demonstrated the therapeutic potential of C. flexuosus essential oil, especially in its nanostructured form, which can be demonstrated against infections caused by rapidly growing mycobacteria.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cymbopogon/química , Micobactérias não Tuberculosas/efeitos dos fármacos , Óleos Voláteis/farmacologia , Exsudatos de Plantas/farmacologia , Biofilmes/crescimento & desenvolvimento , Brasil , Emulsões , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Óleos de Plantas/química , Óleos de Plantas/farmacologiaRESUMO
Bacterial biofilms are involved in various medical infections and for this reason it is of great importance understanding adhesion mechanisms of involved microorganisms is essential to develop new strategies of prevention and control. Different approaches have been used for preventing biofilm related infections in health care settings, such as use of surface coatings agents in medical implants. In this context, is necessary to explore new compounds with anti-biofilm activity. Thus, this study evaluated for the first time the action of A22 against biofilms of Pseudomonas aeruginosa PAO1 strain and multi-resistant clinical isolates on biotic and abiotic surfaces. A22 acts as inhibitor of the MreB protein of the bacterial cell wall, causing the rods to change shape to the coccoid form. In this work, A22 at subinhibitory concentrations was able to prevent biofilm formation, and atomic force microscopy images showed that A22 was highly effective in inhibiting adhesion on polyethylene surfaces. Pseudomonas aeruginosa PAO1 exhibited a strong ability to adhere to HeLa cells, and A22 inhibited the aggregation after 4 h of exposure. Swarming and twitching motilities were significantly altered by A22 at subinhibitory concentrations. Thus, by changing the shape of the bacterial cell, many properties can be affected, such as motility, surface adhesion and biofilm formation. This work presents A22 as a promising novel antibacterial or surface coating agent of medical materials.
Assuntos
Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Tioureia/análogos & derivados , Proteínas de Bactérias/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Parede Celular , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Polietileno , Tioureia/antagonistas & inibidores , Fatores de TempoRESUMO
Microbial biofilms represent a challenge in the treatment of infections, due to the low efficacy of the antimicrobials. This study evaluated the antimicrobial effect of nanoparticles of Melaleuca alternifolia (TTO) in dental biofilm. Thirty-eight volunteers used an oral device in situ in situ including four bovine enamel specimens for 07 days. From the fifth day four solutions were applied randomly for each specimen: Physiological Saline Solution (0.85% NaCl) (C+), Chlorhexidine 0.12% (CHX), M. alternifolia oil 0.3% (TTO), and a nanoparticle solution of 0.3% M. alternifolia oil (NPTTO). The nanoparticles of TTO were characterized for pH, IPD, medium size, zeta potential and Transmission Electron Microscopy. Antimicrobial activity was evaluated by viable microorganisms count and the structure of the biofilm by atomic force microscopy. The NPTTO presented pH 6.4, particle diameter of 197.9 ± 1 nm, polydispersion index of 0.242 ± 0.005, zeta potential of -7.12 mV and ±0:27 spherical shape. The C+ resulted in 100% of bacterial vitality, while CHX, TTO and NPTTO showed 34.2%, 51.4% and 25.8%, respectively. The AFM images showed biofilms with an average roughness of 350 nm for C+, 275 nm for CHX, 500 nm for TTO and 100 nm for NPTTO. The NPTTO demonstrated excellent antimicrobial activity in the biofilm formed in situ and will possibly be used in future for the treatment/prevention of oral biofilms.
Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Melaleuca/química , Nanopartículas/química , Exsudatos de Plantas/farmacologia , Adulto , Animais , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Brasil , Bovinos , Clorexidina/farmacologia , Contagem de Colônia Microbiana , Esmalte Dentário/microbiologia , Placa Dentária/tratamento farmacológico , Placa Dentária/microbiologia , Placa Dentária/prevenção & controle , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Tamanho da Partícula , Projetos Piloto , Cloreto de Sódio/farmacologia , Óleo de Melaleuca/farmacologia , Fatores de Tempo , Adulto JovemRESUMO
Calyptranthes tricona is a species (Myrtaceae) native to South Brazil. Plants belonging to this family are folkloric used for analgesia, inflammation, and infectious diseases. However, little is known about the toxic potential of C. tricona. The present study aimed to evaluate the antioxidant activity of C. tricona ethanol and hexane leaf extracts, as well as verify their effect on human lymphocytes and MCF-7 cells. The extracts were subjected to preliminary phytochemical screening, antioxidant activity using DPPH and ORAC methods. Genotoxic and mutagenic effects in cultured human lymphocytes were assessed using the comet assay and the micronucleus assay, respectively. In addition, cell viability by MTT assay and fluorometric analysis of mitochondrial potential and caspases-9 activity were performed in order to verify the possible effects of both extracts on H2O2-induced cell death of MCF-7 cells. Our findings revealed that the phenol content and the antioxidant activity were only present in the ethanol extract. Also, the phytochemical screening presented steroids, triterpenoids, condensed tannins, and flavones as the main compounds. However, both extracts were capable of inducing concentration-dependent DNA damage in human lymphocytes. When treating MCF-7 cells with the extracts, both of them inhibited MCF-7 cell death in response to oxidative stress through a decrease of mitochondrial depolarization and caspases-9 activity. Thus, our results need to be considered in future in vitro and in vivo studies of C. tricona effects. In the meanwhile, we recommend caution in the acute/chronic use of this homemade preparation for medicinal purpose.
Assuntos
Dano ao DNA , Peróxido de Hidrogênio/farmacologia , Linfócitos/metabolismo , Myrtaceae/química , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Morte Celular/efeitos dos fármacos , Feminino , Humanos , Linfócitos/patologia , Células MCF-7 , Extratos Vegetais/químicaRESUMO
Candida albicans does not only occur in the free living planktonic form but also grows in surface-attached biofilm communities. Moreover, these biofilms appear to be the most common lifestyle and are involved in the majority of human Candida infections. Nanoparticles can be used as an alternative to conventional antimicrobial agents and can also act as carriers for antibiotics and other drugs. In view of this, the aim of the study was develop, characterize and verify the anti-biofilm potential of GML Nanocapsules against C. albicans. The GML Nanocapsules showed mean diameter of 193.2 nm, polydispersion index of 0.044, zeta potential of -23.3 mV and pH 6.32. The microdilution assay showed MIC of 15.5 µg mL(-1) to GML Nanocapsules and 31.25 µg mL(-1) to GML. The anti-biofilm assay showed the significantly reduction of biomass of C. albicans biofilm treated with GML Nanocapsules while the GML does not exhibit effect. The kinetic assay demonstrated that at 48 h, the GML Nanocapsules reduce 94% of formed biofilm. The positive results suggest the promisor alternative for this public health problem that is biofilm infections.
Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Lauratos/farmacologia , Monoglicerídeos/farmacologia , Nanocápsulas , Candida albicans/fisiologia , Testes de Sensibilidade MicrobianaRESUMO
Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective alternative to reduce the adhesion of microorganisms and prevent infections resulting from the use of some hospital medical materials.
Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Equipamentos e Provisões/microbiologia , Pelargonium/química , Extratos Vegetais/farmacologia , Antifúngicos/isolamento & purificação , Candida/fisiologia , Emulsões/farmacologia , Hospitais , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificaçãoRESUMO
PURPOSE: To evaluate the effectiveness of a desensitizing gel for topical and home use for the treatment of dentin hypersensitivity (DH) by means of a 3-arm parallel, randomized, double blind clinical trial. METHODS: 107 participants were allocated to three groups: placebo gel (PG), test gel (TG) (5% sodium fluoride, 5% potassium oxalate, 10% strontium chloride) and 2% sodium fluoride gel (FG). DH measurement was performed by a single blind examiner by means of the visual analog scale (VAS) after tactile (blunt tipped probe), thermal (air blast) and osmotic (water blast) stimulus at time intervals of baseline, 7, 15 and 30 days. RESULTS: The greatest reductions in DH were observed for the TG, with significant differences for FG in the thermal (Δ = -56 vs -30) and osmotic stimuli (Δ = -44 vs -18). Considering the percentage of participants with moderate/severe pain at 30 days, the TG demonstrated the lowest percentages, with significant differences in comparison with the other groups in thermal and osmotic stimuli. We can conclude that the test gel showed a greater reduction in DH than fluoride 2% and placebo gel, and maybe a treatment option for individuals with DH.
Assuntos
Sensibilidade da Dentina/tratamento farmacológico , Ácido Oxálico/administração & dosagem , Fluoreto de Sódio/administração & dosagem , Estrôncio/administração & dosagem , Administração Tópica , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The objective of this work was to prepare and characterize liposomes containing co-encapsulated ascorbic acid (AA) and ascorbyl palmitate (AP), as well as to evaluate their stability, cytotoxicity, antioxidant, and antimicrobial activity. Through the pre-formulation studies, it was possible to improve the formulation, as leaving it more stable and with a greater antioxidant activity, resulting in a formulation designated LIP-AAP, with 161 nm vesicle size, 0.215 polydispersity index, -31.7 mV zeta potential, and pH of 3.34. Encapsulation efficiencies were 37% for AA and 79% for AP, and the content was 1 mg/mL for each compound. The optimized liposomes demonstrated stability under refrigeration for 60 days, significant antioxidant activity (31.4 µMol of TE/mL), and non-toxicity, but no antimicrobial effects against bacteria and fungi were observed. These findings confirm that the co-encapsulated liposomes are potent, stable antioxidants that maintain their physical and chemical properties under optimal storage conditions.
RESUMO
The honeybee disease American foulbrood (AFB) is a serious problem since its causative agent (Paenibacillus larvae) has become increasingly resistant to conventional antibiotics. One of the feasible alternative treatments being used for control of this disease are plants extracts. The aim of the present work was to evaluate the effect of crude extract and fractions of Scutia buxifolia against six Paenibacillus species, including P. larvae, and its potential use for the control of AFB. In vitro activity of S. buxifolia samples against Paenibacillus species were evaluated by the disk diffusion and microdilution methods, and the minimal inhibitory concentration (MIC) were also determined. All Paenibacillus species were sensitive to crude extract and fractions of S. buxifolia. The dichloromethane (DC) fraction showed the better MIC (1.56 mg/mL), followed by ethyl acetate (EtAc) (6.25 mg/mL), n-butanol (BuOH) (25 mg/mL) and Crude extract (CE) (50 mg/mL). Toxic effect of S. buxifolia crude extracts and fractions against bees were also evaluated by the spraying application method of the same concentrations of MICs. The samples tested showed no toxic effects for the bees after 15 days of observation. These results are first time described for this species and showed that S. buxifolia presented a important activity against Paenibacillus species and proved to be a natural alternative for the prevention/control of AFB.
Assuntos
Anti-Infecciosos/farmacologia , Abelhas/microbiologia , Infecções por Bactérias Gram-Positivas/veterinária , Viabilidade Microbiana/efeitos dos fármacos , Paenibacillus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Rhamnaceae , Animais , Anti-Infecciosos/química , Anti-Infecciosos/toxicidade , Abelhas/efeitos dos fármacos , Fracionamento Químico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Estimativa de Kaplan-Meier , Larva/efeitos dos fármacos , Larva/microbiologia , Longevidade/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Paenibacillus/patogenicidade , Extratos Vegetais/química , Extratos Vegetais/toxicidadeRESUMO
Twenty-three isolates of Staphylococcus aureus resistant to methicillin have been analyzed, being found a clinical isolate of VISA through microdilution technique. The others techniques were unable to detect such isolates. This is the first study that shows the presence of VISA in clinical isolates in the city of Santa Maria-RS.
RESUMO
This manuscript presents the first report on antimicrobial photo-inactivation in vitro using tetra-cationic porphyrins with peripheral platinum(II) bipyridyl complexes against Gram-positive bacteria. Two isomeric tetra-cationic porphyrins (3TPyP and 4TPyP) were tested against clinically important bacterial species. The antimicrobial activity assays were performed at specific photosensitizer (PS) concentrations under dark and white-light LED irradiation conditions for 120 min. The porphyrin 3-PtTPyP was the most efficient PS against the bacteria tested, inhibiting bacterial growth in just 15 min and 30 min at low concentrations (3.75 and 0.45 µM). The minimal inhibitory concentration of the porphyrin increased in the presence of reactive oxygen species scavengers, indicating that singlet oxygen and radical species likely participated in the photo-oxidation mechanism. In addition, the checkerboard assay that tests the association of compounds, showed a synergistic effect, suggesting a potentiation of the antibacterial effect when porphyrin was tested in combination with ciprofloxacin and vancomycin. Thus, tetra-cationic porphyrins containing platinum(II) complexes are promising agents for microbial photo-inactivation as an alternative therapy against infections.
Assuntos
Anti-Infecciosos , Fotoquimioterapia , Porfirinas , Platina/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Fotoquimioterapia/métodos , Enterococcus , Staphylococcus , Porfirinas/farmacologia , Antibacterianos/farmacologia , BactériasRESUMO
This manuscript presents the cytotoxicity, antimicrobial activity, antibiofilm preliminary properties, and associated therapy with commercial drugs using water-soluble tetra-cationic porphyrins against Pseudomonas aeruginosa. Two commercial tetra-cationic porphyrins were tested against a standard strain of P. aeruginosa 01 (PA01) in antibacterial activity assays under dark conditions and irradiated with white light for 120 min. Porphyrin 4-H2TMePor showed better antimicrobial activity and was chosen for further tests. Increased minimum inhibitory concentration was observed in the presence of reactive oxygen species, suggesting that photooxidation was mediated by the singlet oxygen production. In the time-kill curve assay, 4-H2TMePor inhibited bacterial growth in 90 min of irradiation. The checkerboard assay revealed synergistic interactions. Biofilms of the standard PA01 strain and three clinical isolates were formed. The biofilm destruction assay was more efficient for PA01, significantly reducing the biofilm biomass formed compared to the positive control. The associated treatment to destroy the biofilm potentiated a significant decrease in the biofilm biomass compared to the positive control. The photosensitizer did not damage human keratinocytes or mouse fibroblasts in the cytotoxicity assays, demonstrating the safety of using 4-H2TMePor. Atomic force microscopy indicated lower adhesion force, higher cell wall deformation, and higher dissipation energy in the treated control compared to untreated PA01. Given our findings, it is evident that water-soluble tetra-cationic porphyrins have excellent antimicrobial and a preliminary antibiofilm activity against Gram-negative bacteria, proving to be a potential photosensitizer for clinical use.