RESUMO
Viral infections may predispose the airways to secondary bacterial infections that can lead to unfavorable progression of principally self-limiting illnesses. Such complicated respiratory infections include pneumonia, bronchitis, sinusitis, acute otitis media, and sepsis, which cause high morbidity and lethality. Some of the pathogenic consequences of viral infections, like the expression of bacterial adhesion receptors and the disturbance of physical barrier integrity due to inflammation, may create permissive conditions for co-infections. Influenza virus A (H3N2) is a major pathogen that causes secondary bacterial infections and inflammation that lead to pneumonia. The herbal medicine Echinacea purpurea, on the other hand, has been widely used to prevent and treat viral respiratory infections, and recent clinical data suggest that it may prevent secondary infection complications as well. We investigated the role of standardized E. purpurea (Echinaforce® extract or EF) on H3N2-induced adhesion of live nontypeable Haemophilus influenzae (NTHi) and Staphylococcus aureus, along with the expression of bacterial receptors, intracellular adhesion molecule-1 (ICAM-1), fibronectin, and platelet activating factor receptor (PAFr), by BEAS-2B cells. Inflammatory processes were investigated by determining the cellular expression of IL-6 and IL-8 and the involvement of Toll-like receptor (TLR-4) and NFκB p65. We found that influenza virus A infection increased the adhesion of H. influenzae and S. aureus to bronchial epithelial cells via upregulated expression of the ICAM-1 receptor and, to some extent, of fibronectin and PAFr. Echinaforce (EF) significantly reduced the expression of ICAM-1, fibronectin, and PAFr and consequently the adhesion of both bacterial strains. EF also effectively prevented the super-expression of inflammatory cytokines by suppressing the expression of NFκB and possibly TLR-4. These results indicate that E. purpurea has the potential to reduce the risk of respiratory complications by preventing virus-induced bacterial adhesion and through the inhibition of inflammation super-stimulation (cytokine storms).
Assuntos
Anti-Infecciosos/farmacologia , Echinacea/química , Células Epiteliais/efeitos dos fármacos , Superinfecção/prevenção & controle , Receptor 4 Toll-Like/antagonistas & inibidores , Fator de Transcrição RelA/antagonistas & inibidores , Linhagem Celular , Coinfecção , Células Epiteliais/citologia , Células Epiteliais/microbiologia , Células Epiteliais/virologia , Fibronectinas/genética , Fibronectinas/imunologia , Regulação da Expressão Gênica , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/crescimento & desenvolvimento , Haemophilus influenzae/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H3N2/patogenicidade , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/virologia , Extratos Vegetais/farmacologia , Glicoproteínas da Membrana de Plaquetas/genética , Glicoproteínas da Membrana de Plaquetas/imunologia , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/imunologia , Transdução de Sinais , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Superinfecção/microbiologia , Superinfecção/virologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologiaRESUMO
Cedar leaf oil (CLO), derived from the Western red cedar, Thuja plicata, was evaluated as a safe and acceptable broad spectrum antimicrobial agent, with a view to its potential applications in buildings, including the alleviation of sick building syndrome. Various Gram-positive and Gram-negative human bacteria, and two fungal organisms, all known to be common environmental sources of potential infection, were selected and tested quantitatively, and all of them were found to be susceptible to CLO liquid and vapor. Bacterial spores and Aspergillus niger were sensitive, although less so than the vegetative bacteria. Similar tests with cultured human lung cells showed that continuous exposure to CLO vapor for at least 60 minutes was not toxic to the cells. Based on these results, CLO shows promise as a prospective safe, green, broad-spectrum anti-microbial agent for decontamination of buildings.
Assuntos
Anti-Infecciosos/farmacologia , Folhas de Planta/química , Óleos de Plantas/farmacologia , Thuja/química , Testes de Sensibilidade MicrobianaRESUMO
The methanol extract of the underground part of Rhodiola rosea was found to show inhibitory activity against Staphylococcus aureus. Bioactivity-guided fractionation of a 95% ethanol extract from the stems of R. rosea led to the isolation of five compounds: gossypetin-7-O-L-rhamnopyranoside (1), rhodioflavonoside (2), gallic acid (3), trans-p-hydroxycinnamic acid (4) and p-tyrosol (5). Their structures were elucidated by UV, IR, MS and NMR data, as well as by comparison with those of the literature. Compounds 1 and 2 were evaluated for their antibacterial and antiprostate cancer cell activities. Compounds 1 and 2 exhibited activity against Staphylococcus aureus with minimum inhibitory concentrations of 50 microg/mL and 100 microg/mL, respectively. Cytotoxicity studies of 1 and 2 also displayed activity against the prostate cancer cell line with IC(50) values of 50 microg/mL and 80 microg/mL, respectively.