RESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) infection is challenging to eradicate because of antibiotic resistance and biofilm formation. Novel antimicrobial agents and alternative therapies are urgently needed. This study aimed to evaluate the synergy of sanguisorbigenin (SGB) isolated from Sanguisorba officinalis L. with six conventional antibiotics to achieve broad-spectrum antibacterial action and prevent the development of resistance. A checkerboard dilution test and time-to-kill curve assay were used to determine the synergistic effect of SGB combined with antibiotics against MRSA. SGB showed significant synergy with antibiotics and reduced the minimum inhibitory concentration of antibiotics by 2-16-fold. Biofilm inhibition assay, quantitative RT-PCR, crystal violet absorption, and transmission electron microscopy were performed to evaluate the synergy mechanism. The results indicated that SGB could inhibit biofilm formation and alter cell membrane permeability in MRSA. In addition, SGB was found to exhibit quite low cytotoxicity and hemolysis. The discovery of the superiority of SGB suggests that SGB may be an antibiotic adjuvant for use in combination therapy and as a plant-derived antibacterial agent targeting biofilms.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Biofilmes , Permeabilidade da Membrana Celular , Testes de Sensibilidade MicrobianaRESUMO
Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is a representative pathogen that produces numerous virulence factors involving manifold cytotoxins and exotoxins. The present study was designed to investigate the influence of Eleutheroside K (ETSK), a single compound isolated from the leaves of Acanthopanax (A.) henryi (Oliv.) Harms, on the exotoxins secreted by MRSA. The transcription and translation of the exotoxins (α-hemolysin and staphylococcal enterotoxins) related to virulence in S. aureus were determined via quantitative RT-PCR and western blot analysis. The effect of ETSK on the production of tumor necrosis factor (TNF)-α was evaluated using enzyme-linked immunosorbent assay. As a result, ETSK at sub-MIC concentrations could reduce the protein expression of α-hemolysin and enterotoxin, and the expression of genes that regulate virulence factors was also inhibited. In addition, the TNF-inducing activity of S. aureus was attenuated by ETSK in a dose-dependent manner. These results revealed that ETSK not only reduced the protein and gene expression levels of related exotoxins but also suppressed the ability of S. aureus to induce macrophages to release cytokines. This study indicated that the inhibition of MRSA infection by ETSK may be achieved by reducing the virulence of S. aureus and highlighted the potential of ETSK as an innovative strategy for the prevention and treatment of MRSA infections.
Assuntos
Eleutherococcus , Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Extratos Vegetais , Staphylococcus aureus , VirulênciaRESUMO
BACKGROUND: The current antimicrobial therapy is still important for the treatment of pneumonia due to MRSA infection, but there are some limitations, including the route of administration, side effect profile, and increased microbial resistance patterns. Therefore, we investigated whether BV, which shows a strong antimicrobial effect against MRSA, would be effective in a pneumonia model. METHODS: In vitro, we checked MIC, qRT-PCR, western blot, ELISA, LDH-assay. In vivo, we checked survival rate, gross pathological change, histopathology, lung bacterial clearance assay, and the expression of inflammatory related gene. RESULTS: The minimum inhibitory concentration of BV against MRSA is 15.6 µg/ml by broth dilution method. The production of toxins and related gene were reduced by BV in MRSA. The secretion of cytokines were decreased by treatment with BV in 264.7 RAW macrophages stimulated by MRSA Also, BV protected A549 from pathogenicity of MRSA. Bee venom reduced the number of bacteria in the lungs and alleviated the symptoms of MRSA-induced pneumonia in mouse. CONCLUSION: BV inhibited the virulence of the bacterium and the number of bacterial cells present in lung tissue, thereby alleviating the symptoms of pneumonia in mice. This study suggested that BV may be a candidate substance for the treatment of pneumonia caused by MRSA infection.
Assuntos
Antibacterianos/farmacologia , Apiterapia , Venenos de Abelha/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pneumonia Estafilocócica/tratamento farmacológico , Células A549 , Animais , Anti-Inflamatórios/farmacologia , Modelos Animais de Doenças , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Células RAW 264.7 , República da CoreiaRESUMO
Cryptotanshinone (CTT) is a natural product and a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miltiorrhizabunge. Notably, CTT has a variety of anti-cancer actions, including the activation of apoptosis, anti-proliferation, and reduction in angiogenesis. We further investigated the anti-cancer effects of CTT using MTS, LDH, and Annexin V assay, DAPI staining, cell cycle arrest, and Western blot analysis in NSCLC cell lines. NSCLC cells treated with CTT reduced cell growth through PI3K/Akt/GSK3ß pathway inhibition, G0/G1 cell cycle arrest, and the activation of apoptosis. CTT induced an increase of caspase-3, caspase-9, poly-ADP-ribose polymerase (PARP), and Bax, as well as inhibition of Bcl-2, survivin, and cellular-inhibitor of apoptosis protein 1 and 2 (cIAP-1 and -2). It also induced G0/G1 phase cell cycle arrest by decreasing the expression of the cyclin A, cyclin D, cyclin E, Cdk 2, and Cdk 4. These results highlight anti-proliferation the latent of CTT as natural therapeutic agent for NSCLC. Therefore, we investigated the possibility of CTT as an anti-cancer agent by comparing with GF, which is a representative anti-cancer drug.
Assuntos
Apoptose/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Fenantrenos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Transdução de Sinais/efeitos dos fármacosRESUMO
The objective of the present study was to investigate the antibacterial activity of a single constituent, ursolic acid 3-O-α-L-arabinopyranoside (URS), isolated from the leaves of Acanthopanax henryi (Oliv.) Harms, alone and in combination with oxacillin (OXA) against methicillin-resistant Staphylococcus aureus (MRSA). A broth microdilution assay was used to determine the minimal inhibitory concentration (MIC). The synergistic effects of URS and OXA were determined using a checkerboard dilution test and time-kill curve assay. The mechanism of action of URS against MRSA was analyzed using a viability assay in the presence of a detergent and an ATPase inhibitor. Morphological changes in the URS-treated MRSA strains were evaluated via transmission electron microscopy (TEM). In addition, the producing penicillin-binding protein 2a (PBP2a) protein level was analyzed using western blotting. The MIC value of URS against MRSA was found to be 6.25 µg/ml and there was a partial synergistic effect between OXA and URS. The time-kill growth curves were suppressed by OXA combined with URS at a sub-inhibitory level. Compared to the optical density at 600 nm (OD600) value of URS alone (0.09 µg/ml), the OD600 values of the suspension in the presence of 0.09 µg/ml URS and 0.00001% Triton X-100 or 250 µg/ml N,N'-dicyclohexylcarbodiimide reduced by 56.6 and 85.9%, respectively. The TEM images of MRSA indicated damage to the cell wall, broken cell membranes and cell lysis following treatment with URS and OXA. Finally, an inhibitory effect on the expression of PBP2a protein was observed when cells were treated with URS and OXA compared with untreated controls. The present study suggested that URS was significantly active against MRSA infections and revealed the potential of URS as an effective natural antibiotic.
Assuntos
Antibacterianos/farmacologia , Parede Celular/efeitos dos fármacos , Glicosídeos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Oxacilina/farmacologia , Triterpenos/farmacologia , Antibacterianos/isolamento & purificação , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Combinação de Medicamentos , Sinergismo Farmacológico , Eleutherococcus/química , Glicosídeos/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/metabolismo , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Extratos Vegetais/química , Folhas de Planta/química , Triterpenos/isolamento & purificação , Ácido UrsólicoRESUMO
BACKGROUND: Black ginseng (Panax ginseng C. A. Meyer), three to nine times-steamed and dried ginseng, has biological and pharmacological activities. In this study, the anti-diabetic effects of the black ginseng ethanol extract (GBG05-FF) in typical type 2 diabetic model db/db mice were investigated. METHODS: The effect of GBG05-FF in Type 2 diabetic mice was investigated by their blood analysis, biological mechanism analysis, and histological analysis. RESULTS: The mice group treated with GBG05-FF showed decreased fasting blood glucose and glucose tolerance compared to that of the nontreated GBG05-FF group. In the blood analysis, GBG05-FF decreased main plasma parameter such as HbA1c, triglyceride, and total-cholesterol levels related to diabetes and improved the expression of genes and protein related to glucose homeostasis and glucose uptake in the liver and muscle. The histological analysis result shows that GBG05-FF decreased lipid accumulation in the liver and damage in the muscle. Moreover, GBG05-FF increased the phosphorylation of the AMPK in the liver and upregulated the expression of GLUT2 in liver and GLUT4 in muscle. Therefore, the mechanisms of GBG05-FF may be related to suppressing gluconeogenesis by activating AMPK in the liver and affecting glucose uptake in surrounding tissues via the upregulation of GLUT2 and GLUT4 expression. CONCLUSION: These findings provided a new insight into the anti-diabetic clinical applications of GBG05-FF and it might play an important role in the development of promising functional foods and drugs from the viewpoint of the chemical composition and biological activities.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 4/genética , Hipoglicemiantes/administração & dosagem , Panax/química , Extratos Vegetais/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Animais , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Transportador de Glucose Tipo 2/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Triglicerídeos/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Araliasaponin II (AS II) is a bioactive compound isolated from Acanthopanax henryi (Oliv.) Harms, a plant widely used in traditional oriental medicine. The present study investigated the antiinflammatory effects of AS II using murine macrophages. The effects of AS II on inflammatory mediator and cytokine production in lipopolysaccharide (LPS)stimulated RAW 264.7 cells was evaluated. Nitric oxide (NO) and cytokine production were determined using the Griess reagent and an ELISA kit. The expression levels of cytokines, inducible NO synthase (iNOS) and cyclooxygenase2 (COX2) mRNA were examined by reverse transcriptionquantitative polymerase chain reaction. The expression levels of iNOS, COX2 and tolllike receptor (TLR)4 protein were examined by western blotting. Translocation of nuclear factorκB (NFκB) and TLR4 expression were visualized by immunofluorescence staining. AS II markedly inhibited the production of NO and prostaglandin E2, and reduced iNOS and COX2 expression at the transcriptional and translational levels. AS II downregulated the expression of interleukin6 and tumor necrosis factorα at the protein and mRNA levels. Furthermore, pretreatment with AS II significantly suppressed the TLR4NFκB signaling pathway; this effect may be cause by AS II competing with LPS for binding to TLR4 and subsequently inhibiting translocation of the NFκB/p65 protein to the nucleus. The results suggested that the antiinflammatory properties of AS II may result from inhibiting proinflammatory mediators by suppressing the initiation of the inflammatory response and inhibiting TLR-4-NF-κB signaling pathways.
Assuntos
Anti-Inflamatórios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta/química , Plantas Medicinais/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Biomarcadores , Citocinas/genética , Citocinas/metabolismo , Dinoprostona/metabolismo , Mediadores da Inflamação/metabolismo , Macrófagos/imunologia , Camundongos , Óxido Nítrico/metabolismo , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Células RAW 264.7RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng C. A. Meyer, Araliaceae) has been used as a traditional medicine for thousands of years for the treatment of a wide variety of diseases, including diabetes. Processed ginseng named Black ginseng exhibits more potent biological activities than white and red ginseng. The aim of this study was to investigate the effects of black ginseng extract (GBG05-FF) on hyperglycemia and glucose tolerance in streptozotocin (STZ)-induced diabetic mice. MATERIALS AND METHODS: Black ginseng was produced by a repeated steaming and drying process, subsequent extraction with 70% ethanol, filtration, and lyophilization. The effect of GBG05-FF on glucose uptake and related protein expression and phosphorylation were determined in C2C12 cells. Furthermore, we evaluated the anti-diabetic effects of GBG05-FF in STZ-induced diabetic mice. RESULTS: GBG05-FF significantly (p<0.05) increased glucose uptake in C2C12 myotubes via AMPK, Sirt1 and PI3-K pathway. In addition, GBG05-FF improved the fasting blood glucose levels and glucose tolerance in STZ-induced diabetic mice. GBG05-FF decreased blood parameters such as glycated hemoglobin, triglyceride and total cholesterol. Quantitative RT-PCR assay revealed that in the STZ-induced diabetic mice treated with GBG05-FF, the expression of hepatic genes involved in gluconeogenesis (phosphoenolpyruvate carboxykinase (PEPCK), glucose 6-phosphatase (G6Pase)), glycogenolysis (liver glycogen phosphorylase (LGP)) and glycogenesis (glycogen synthase (GS)) was suppressed, while the expression of the genes involved in glucose uptake (glucose transporter (GLUT) 1, GLUT4) and ß-oxidation (acyl-CoA oxidase (ACO), carnitine palmitoyl transferase 1a (CPT1a), mitochondrial medium chain acyl-CoA dehydrogenase (MCAD)) in muscle were increased. GBG05-FF delayed diabetes-associated muscle atrophy by activating mTOR. The major bioactive compounds including ginsenoside Rg1, Rg3(S), Rg3(R), Rg5, Rk1 and Rh4 were evaluated for glucose uptake effect in C2C12 myotubes; the data indicated that Rh4 significantly (p<0.05) increased glucose uptake. CONCLUSION: Collectively, the results suggested that GBG05-FF is a potentially useful agent for treatment of diabetes by increasing glucose uptake.
Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Fígado/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Panax/química , Extratos Vegetais/farmacologia , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Linhagem Celular , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/enzimologia , Relação Dose-Resposta a Droga , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Hipoglicemiantes/isolamento & purificação , Insulina/sangue , Fígado/enzimologia , Masculino , Camundongos Endogâmicos ICR , Fibras Musculares Esqueléticas/enzimologia , Panax/classificação , Fosforilação , Fitoterapia , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Transdução de Sinais/efeitos dos fármacos , Estreptozocina , Fatores de TempoRESUMO
Shikonin (SKN), a highly liposoluble naphthoquinone pigment isolated from the roots of Lithospermum erythrorhizon, is known to exert antibacterial, wound-healing, anti-inflammatory, antithrombotic, and antitumor effects. The aim of this study was to examine SKN antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The SKN was analyzed in combination with membrane-permeabilizing agents Tris and Triton X-100, ATPase inhibitors sodium azide and N,N'-dicyclohexylcarbodiimide, and S. aureus-derived peptidoglycan; the effects on MRSA viability were evaluated by the broth microdilution method, time-kill test, and transmission electron microscopy. Addition of membrane-permeabilizing agents or ATPase inhibitors together with a low dose of SKN potentiated SKN anti-MRSA activity, as evidenced by the reduction of MRSA cell density by 75% compared to that observed when SKN was used alone; in contrast, addition of peptidoglycan blocked the antibacterial activity of SKN. The results indicate that the anti-MRSA effect of SKN is associated with its affinity to peptidoglycan, the permeability of the cytoplasmic membrane, and the activity of ATP-binding cassette (ABC) transporters. This study revealed the potential of SKN as an effective natural antibiotic and of its possible use to substantially reduce the use of existing antibiotic may also be important for understanding the mechanism underlying the antibacterial activity of natural compounds.
RESUMO
Human skin is the first line of defense for the protection of the internal organs of the body from different stimuli. Ultraviolet B (UVB), one of the harmful radiations for skin, is widely known to induce abnormally increased cytokine release from keratinocytes leading to inflammatory skin disorders. IL-6 and IL-8 induce an acute-phase response and stimulate leukocyte infiltration in the skin. Previous studies have shown that chronic exposure to UVB radiation increases cyclooxygenase-2 (COX2) expression through various cell signaling pathways, resulting in skin cancer. Recent studies have shown that the activation of extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 MAPK is strongly correlated with acute inflammation and development of skin cancer caused by an increased expression of COX-2. Ixerisoside A (IXA) is an active constituent of Ixeris dentata of the Compositae (Asteraceae) family. The effect of IXA on skin inflammation has yet to be elucidated. To determine the anti-inflammatory effects of IXA, we examined its effect on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of IXA. In this study, pro-inflammatory cytokine production was determined by enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (rt-pcr), and western blot analysis to evaluate the activation of mitogen-activated protein kinases (MAPKs). IXA inhibited UVB-induced production of the pro-inflammatory cytokines IL-6 and IL-8 in a dose-dependent manner. Moreover, IXA inhibited the expression of COX-2, ERK, JNK, and p38 MAPKs, indicating that the secretion of the pro-inflammatory cytokines IL-6 and IL-8, and COX-2 expression was inhibited by blocking MAPK phosphorylation. These results indicated that IXA potentially protects against UVB-induced skin inflammation.
Assuntos
Citocinas/biossíntese , Mediadores da Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lactonas/farmacologia , Substâncias Protetoras/farmacologia , Sesquiterpenos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Citocinas/genética , Ativação Enzimática/efeitos dos fármacos , Expressão Gênica , Humanos , Queratinócitos/efeitos da radiação , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Extratos Vegetais/farmacologia , Raios UltravioletaRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) infection is a serious clinical problem worldwide. The aim of the present study was to examine the antimicrobial activity of oxyresveratrol (ORV) against MRSA. The antimicrobial activity of ORV was evaluated against three strains of MRSA and one methicillin-susceptible S. aureus (MSSA) strain using a minimal inhibitory concentration (MIC) assay, MTT colorimetric assay, checkerboard dilution test and time-kill assay. The MIC of ORV for all strains was moderate at 125 µg/ml. Of note, the antimicrobial activity and fractional inhibitory concentration index values of ORV were markedly increased in the presence of a non-growth inhibitory dose of certain antibiotics. Time-kill curves revealed that a combination of ORV with ciprofloxacin or with gentamicin reduced bacterial counts to below the lowest detectable limit after 24 h. These effective combinations may be used as potential antimicrobial regimens for use in the management of MRSA.
Assuntos
Sinergismo Farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Estilbenos/administração & dosagem , Antibióticos Antituberculose/administração & dosagem , Ciprofloxacina/administração & dosagem , Gentamicinas/administração & dosagem , Humanos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologiaRESUMO
Galla rhois is a commonly used traditional medicine for the treatment of pathogenic bacteria in Korea as well as in other parts of Asia. Methyl gallate (MG), a major component of Galla Rhois, exhibits strong antibacterial activity, but its mechanism of action against Salmonella spp. is unclear. In the present study, we investigated the antibacterial actions of MG against Salmonella. The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of MG against Salmonella strains ranged from 3.9 to 125 µg/ml. In vitro bacterial viability test indicated that MG significantly decreased the viability of Salmonella over 40% when combined with ATPase inhibitors. The time-kill curves showed that a combined MG and ATPase inhibitors (DCCD and NaN3) treatment reduced the bacterial counts dramatically after 24 h. Oral administration of MG showed a strong anti-bacterial activity against WS-5 infected BALB/c mice. In contrast to the untreated Salmonella infected control animals, MG treated groups showed no clinical symptoms of the disease, such as lethargy and liver damage. It was observed that MG treatment significantly increased the survival of animals from Salmonella infection, while in untreated groups all animal succumbed to disease by the sixth day post infection. Thus, the present study demonstrates the therapeutic ability of MG against Salmonella infections.
Assuntos
Antibacterianos/uso terapêutico , Ácido Gálico/análogos & derivados , Extratos Vegetais/uso terapêutico , Salmonelose Animal/tratamento farmacológico , Salmonella/efeitos dos fármacos , Administração Oral , Anacardiaceae/química , Animais , Antibacterianos/administração & dosagem , Ácido Gálico/administração & dosagem , Ácido Gálico/química , Ácido Gálico/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/administração & dosagem , Extratos Vegetais/químicaRESUMO
Tectorigenin (TTR) is an O-methylated isoflavone derived from the rhizome of Belamacanda chinensis (L.) DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN) derived from S. aureus. Transmission electron microscopy (TEM) was used to monitor survival characteristics and changes in S. aureus morphology. The MIC values of TTR against all the tested strains were 125 µ g/mL. The OD(600) of each suspension treated with a combination of Triton X-100, DCCD, and NaN3 with TTR (1/10 × MIC) had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 µ g/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 µ g/mL directly bind to and inhibit TTR at 62.5 µ g/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.
RESUMO
Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots of Desmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains of S. aureus ranges from 15.6 to 31.25 µ g/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of the ß -lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics ( ß -lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.
RESUMO
Ultraviolet B (UVB) irradiation causes skin damage and inflammation by inducing the secretion of various cytokines, which are immune regulators produced by cells. To prevent skin inflammation, keratinocytes that have been irreversibly damaged by UVB must be eliminated through apoptosis. Ixeris dentata (I. dentata) (family Asteraceae) is a perennial medicinal herb indigenous to Korea. It is used in Korea, China and Japan to treat indigestion, pneumonia, diabetes, hepatitis, contusions and tumors. Guaiane-type sesquiterpene lactones were isolated from the whole extract of I. dentata. This led to the isolation of the anti-inflammatory sesquiterpene lactone compound tectroside (TES), which was tested on a human keratinocyte cell line. To determine the anti-inflammatory effects of TES, we examined its influence on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of TES. In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction and western blot analysis to evaluate the activation of mitogen-activated protein kinases (MAPKs). TES inhibited UVB-induced production of the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 in a dose-dependent manner. In addition, TES inhibited the expression of cyclooxygenase (COX)-2 and the phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) MAPKs, suggesting that it inhibits the secretion of the pro-inflammatory cytokines IL-6 and IL-8 and COX-2 expression by blocking MAPK phosphorylation. These results suggest that TES can potentially protect against UVB-induced skin inflammation.
Assuntos
Anti-Inflamatórios/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Lactonas/farmacologia , Sesquiterpenos de Guaiano/farmacologia , Raios Ultravioleta/efeitos adversos , Anti-Inflamatórios/química , Asteraceae/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Ciclo-Oxigenase 2/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-6/biossíntese , Interleucina-8/biossíntese , Queratinócitos/metabolismo , Lactonas/química , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , RNA Mensageiro/genética , Sesquiterpenos de Guaiano/químicaRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) are spread among infected patients, with infection rates increasing at an alarming rate. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of infectious diseases worldwide. Under the selection pressure of exposure to antibiotics, microorganisms evolve to survive against the new conditions imposed by therapy. Therefore, there exists a need to develop alternative natural or combination drug therapies. Curcumin (CCM), a natural polyphenolic flavonoid isolated from the rhizome of a plant, Curcuma longa Linné., has been found to possess many beneficial biological activities. The aim of this study was to investigate the synergistic effect of curcumin and antibiotics as well as to determine the antibacterial activity of CCM against specific MRSA strains. The antibacterial activity of CCM was assessed by the broth microdilution method (by calculating the minimal inhibitory concentration [MIC]), checkerboard dilution test, and time-kill assay. Antimicrobial activity of CCM was observed against all tested strains. The MICs of CCM against 10 strains of S. aureus ranged from 125 to 250 µg/ml. In the checkerboard test, CCM markedly reduced the MICs of the antibiotics oxacillin (OXI), ampicillin (AMP), ciprofloxacin (CIP), and norfloxacin (NOR) used against MRSA. The time-kill curves showed that a combined CCM and OXI treatment reduced the bacterial counts below the lowest detectable limit after 24h. This study suggested that CCM reduced the MICs of several antibiotics tested, notably of OXI, AMP, CIP, and NOR, and that CCM in combination with antibiotics could lead to the development of new combination of antibiotics against MRSA infection.
Assuntos
Antibacterianos/farmacologia , Curcuma/química , Curcumina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Ampicilina/farmacologia , Ciprofloxacina/farmacologia , Curcumina/química , Curcumina/isolamento & purificação , Sinergismo Farmacológico , Humanos , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Norfloxacino/farmacologia , Oxacilina/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Rizoma/química , Fatores de TempoRESUMO
OBJECTIVE: Cheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms. METHODS: In this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs. These allergic mediators included interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and ß-hexosaminidase (ß-hex). RESULTS: Our data revealed that CITE inhibited the production of IL-6, PGD2, LTC4, and ß-hex induced by PMA plus A23187 (P<0.05). CONCLUSION: These findings indicate that CITE has the potential for use in the treatment of allergy.
Assuntos
Anti-Inflamatórios/uso terapêutico , Células da Medula Óssea/patologia , Medicamentos de Ervas Chinesas/uso terapêutico , Hipersensibilidade/tratamento farmacológico , Mastócitos/patologia , Animais , Anti-Inflamatórios/farmacologia , Calcimicina/farmacologia , Degranulação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Hipersensibilidade/patologia , Interleucina-6/metabolismo , Leucotrieno C4/farmacologia , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Prostaglandina D2/biossíntese , Acetato de Tetradecanoilforbol/farmacologia , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
OBJECTIVE: To elucidate the molecular mechanisms underlying the anti-inflammatory effects of Danggui Liuhuang Decoction () or Dangkwiyughwang-tang (DGLHT) water extract. METHODS: Effect of DGLHT on the lipopolysaccharide (LPS)-induced production of several pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E(2) (PGE(2)), and interleukin-6 (IL-6) were examined by using enzymelinked immunosorbent assay. To determine the underlying mechanism of the inhibitory effects of DGLHT, the expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) protein, as well as iNOS, COX-2, and IL-6 mRNA levels were examined by Western blot and reverse transcription polymerase chain reaction (RT-PCR). Mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW 264.7 cells were also examined by Western blot. RESULTS: DGLHT inhibited LPS-induced production of NO, PGE(2), and IL-6 productions and the expressions of iNOS and COX-2. Furthermore, DGLHT suppressed LPS-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). CONCLUSIONS: DGLHT has inhibitory effects on the LPSinduced production of PGE(2), NO, and IL-6 and on the expressions of iNOS and COX-2 in murine macrophages. These anti-inflammatory effects occur through inhibition of MAPK phosphorylation.
RESUMO
Tetrandrine (TET) is a bis-benzylisoquinoline alkaloid derived from the radix of Stephania tetrandra S. Moore. TET performs a wide spectrum of biological activities. The radix of S. tetrandrae has been used traditionally in Asia, including Korea, to treat congestive circulatory disorders and inflammatory diseases. The aim of this study was to examine the mechanism of antibacterial activity of tetrandrine against Staphylococcus aureus. The mechanism was investigated by studying the effects of TET in combination with detergent or membrane potential un-couplers. In addition, the direct involvement of peptidoglycan (PGN) was assessed in titration assays. TET activity against S. aureus was 125-250 µg/mL, and the minimum inhibitory concentration (MIC) of the two reference strains was 250 µg/mL. The OD(600) of each suspension treated with a combination of ethylenediaminetetraacetic acid (EDTA), tris(hydroxymethyl) aminomethane (TRIS), and Triton X-100 (TX) with TET (0.25×MIC) had been reduced from 43% to 96%. Additional structure-function studies on the antibacterial activity of TET in combination with other agents may lead to the discovery of more effective antibacterial agents.
Assuntos
Antibacterianos/farmacologia , Benzilisoquinolinas/farmacologia , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/metabolismo , Farmacorresistência Bacteriana , Ácido Edético/química , Inibidores Enzimáticos/farmacologia , Testes de Sensibilidade Microbiana , Octoxinol/química , Peptidoglicano/metabolismo , Staphylococcus aureus/patogenicidade , Stephania tetrandra/química , Trometamina/químicaRESUMO
Punica granatum is commonly used in Korea as a traditional medicine for the treatment of pathogenic bacteria. In this study, we investigated the in vitro and in vivo antimicrobial activity of P. granatum peel EtOH extract (PGPE) against 16 strains of Salmonella. The minimal inhibitory concentrations of PGPE were in the range of 62.5-1000 x03BCg mL(-1). In addition, the in vivo antibacterial activity of the PGPE extract was examined in a S. typhimurium infection mouse model. Mice were initially infected with S. typhimurium and then with PGPE. The extract was found to have significant effects on mortality and the numbers of viable S. typhimurium recovered from feces. Although clinical signs and histological damage were rarely observed in the treated mice, the untreated controls showed signs of lethargy and histological damage in the liver and spleen. Taken together, the results of this study indicate that PGPE has the potential to provide an effective treatment for salmonellosis.