The Ethyl Acetate Subfraction of Polygonum cuspidatum Root Containing Emodin Affect EBV Gene Expression and Induce EBV-Positive Cells Apoptosis.

Epstein-Barr virus (EBV), a human herpesvirus, is several human lymphoid malignancies-associated. Our earlier study found the effect of Polygonum cuspidatum root on promoting EBV-positive apoptosis. Therefore, this study investigated the effects of the Polygonum cuspidatum ethyl acetate subfraction containing emodin on EBV gene expression and anti-EBV tumor cells. Resultantly, the the Polygonum cuspidatum ethyl acetate subfraction containing emodin (F3a) promoted Raji cell death (50% cytotoxic concentration, CC50: 12.08 µg/mL); the 12.5 µg/mL F3a effect transcribed BRLF1 and BNLF1 and increased latent membrane protein 1 (LMP1), which may reduce the intracellular phospho-extracellular signal-regulated kinase (ERK) and phospho-inhibitor of Nuclear factor kappa B α (IκBα). Meanwhile, the Raji cells increased the intracellular reactive-oxygen species (ROS), activated the apoptosis-related proteins, cleaved caspase 3 and poly(ADP-ribose)polymerase (PARP), and increased the apoptosis percentage. Therefore, the Polygonum cuspidatum ethyl acetate subfraction containing emodin could be a therapeutic drug for EBV-related tumors.

The Potential Role of Sulbactam and Cephalosporins Plus Daptomycin Against Daptomycin-Nonsusceptible VISA and H-VISA Isolates: An in Vitro Study.

This study assesses the synergistic effect of the combination of cephalosporins and sulbactam with daptomycin against daptomycin-nonsusceptible, vancomycin-intermediate resistant Staphylococcus aureus (VISA) or heterogeneous vancomycin-intermediate S. aureus (h-VISA) isolates. The in vitro activity of daptomycin against daptomycin-nonsusceptible VISA/h-VISA isolates after adding cephalosporins with or without sulbactam was evaluated. The MIC of daptomycin against the VISA/h-VISA isolates was reduced after adding cephalosporins to daptomycin. Except for one VISA and two h-VISA isolates, the other VISA/h-VISA isolates became daptomycin-susceptible (MICs 1 mg/L). After adding sulbactam to each daptomycin/cephalosporin combination, the MIC of daptomycin against the VISA/h-VISA isolates decreased for 5 (33.3%), 6 (40.0%), 6 (40.0%), and 6 (40.0%) isolates with the cefazolin, cefmetazole, cefotaxime, and cefepime combinations, respectively. Synergism using the checkerboard method was noted in 100% of cefazolin and cefotaxime combinations and 87% and 80% of cefmetazole and cefepime combinations for all the VISA and h-VISA isolates. With the addition of sulbactam, synergism was noted in 100% of cefazolin, cefmetazole, and cefotaxime combinations and 93% of the cefepime combinations for all the VISA and h-VISA isolates. Almost all the FICs for the three-drug combinations were lower than those for the two-drug combinations. Using time-killing methods, a synergistic effect against five h-VISA isolates was observed. A synergistic effect of daptomycin, sulbactam, and each cephalosporin was observed for all VISA isolates. In conclusion, the activity of daptomycin against daptomycin-nonsusceptible VISA/h-VISA isolates can be enhanced by adding cephalosporins, and partially further promoted by sulbactam.

Appropriate composites of cefoperazone-sulbactam against multidrug-resistant organisms.

OBJECTIVES: This study aims to assess the in vitro activity of different cefoperazone-sulbactam ratios against different multidrug-resistant organisms (MDROs). MATERIALS AND METHODS: Minimum inhibitory concentrations (MICs) and susceptibility rates of cefoperazone, sulbactam and cefoperazone-sulbactam at fixed ratios of 2:1, 1:1 and 1:2 against 344 MDRO clinical isolates, including extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (n=58), ESBL-producing Klebsiella pneumoniae (n=58), carbapenem-resistant Enterobacteriaceae (n=57), carbapenem-resistant Pseudomonas aeruginosa (n=49) and carbapenem-resistant Acinetobacter baumannii (n=122), were measured. RESULTS: Combined treatment with sulbactam and cefoperazone resulted in decreased MIC50 values across all MDROs, as well as decreases in most MIC90 values, except for carbapenem-resistant Enterobacteriaceae and carbapenem-resistant P. aeruginosa (MIC90 values remained >64 mg/L). Susceptibility rates of treatment with cefoperazone alone against all MDROs were much lower than that of cefoperazone-sulbactam combination (all P<0.05), except in carbapenem-resistant P. aeruginosa. Additionally, the susceptibility rate gradually increased as the ratio of cefoperazone-sulbactam was adjusted from 2:1 to 1:1 and to 1:2 for carbapenem-resistant Enterobacteriaceae, ESBL-producing K. pneumoniae and carbapenem-resistant A. baumannii. There were no significant ratio-dependent changes in susceptibility rates with cefoperazone-sulbactam in carbapenem-resistant P. aeruginosa. CONCLUSION: Adding sulbactam enhances cefoperazone activity against most MDROs excluding carbapenem-resistant P. aeruginosa, and the activity of cefoperazone-sulbactam against these MDROs is greatest at a ratio of 1:2, followed by ratios of 1:1 and 2:1.

Chronic exposure to Rhodobacter sphaeroides extract Lycogen™ prevents UVA-induced malondialdehyde accumulation and procollagen I down-regulation in human dermal fibroblasts.

UVA contributes to the pathogenesis of skin aging by downregulation of procollagen I content and induction of matrix metalloproteinase (MMP)-associated responses. Application of antioxidants such as lycopene has been demonstrated as a convenient way to achieve protection against skin aging. Lycogen™, derived from the extracts of Rhodobacter sphaeroides, exerts several biological effects similar to that of lycopene whereas most of its anti-aging efficacy remains uncertain. In this study, we attempted to examine whether Lycogen™ could suppress malondialdehyde (MDA) accumulation and restore downregulated procollagen I expression induced by UVA exposure. In human dermal fibroblasts Hs68 cells, UVA repressed cell viability and decreased procollagen I protein content accompanied with the induction of MMP-1 and MDA accumulation. Remarkably, incubation with 50 µM Lycogen™ for 24 h ameliorated UVA-induced cell death and restored UVA-induced downregulation of procollagen in a dose-related manner. Lycogen™ treatment also prevented the UVA-induced MMP-1 upregulation and intracellular MDA generation in Hs68 cells. Activation of NFκB levels, one of the downstream events induced by UVA irradiation and MMP-1 induction, were also prevented by Lycogen™ administration. Taken together, our findings demonstrate that Lycogen™ may be an alternative agent that prevents UVA-induced skin aging and could be used in cosmetic and pharmaceutical applications.

Inhibition of Epstein-Barr virus lytic cycle by an ethyl acetate subfraction separated from Polygonum cuspidatum root and its major component, emodin.

Polygonum cuspidatum is widely used as a medicinal herb in Asia. In this study, we examined the ethyl acetate subfraction F3 obtained from P. cuspidatum root and its major component, emodin, for their capacity to inhibit the Epstein-Barr virus (EBV) lytic cycle. The cell viability was determined by the MTT [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide] method. The expression of EBV lytic proteins was analyzed by immunoblot, indirect immunofluorescence and flow cytometric assays. Real-time quantitative PCR was used to assess the EBV DNA replication and the transcription of lytic genes, including BRLF1 and BZLF1. Results showed that the F3 and its major component emodin inhibit the transcription of EBV immediate early genes, the expression of EBV lytic proteins, including Rta, Zta, and EA-D and reduces EBV DNA replication, showing that F3 and emodin are potentially useful as an anti-EBV drug.

Antiproliferative activity and apoptosis induction of Eucalyptus Citriodora resin and its major bioactive compound in melanoma B16F10 cells.

Antiproliferative activity and apoptosis induction of ethyl acetate of Eucalyptus citriodora resin (EAEER), and its major bioactive compound in melanoma B16F10 cells were investigated. 6-[1-(p-Hydroxy-phenyl)ethyl]-7-O-methyl aromadendrin (HEMA), a flavanol derivative, was isolated from EAEER and identified on the basis of its mass and NMR spectra. The results from MTT assay showed high antiproliferative effects of EAEER and HEMA on B16F10 cells. Moreover, EAEER- and HEMA-induced cell apoptosis was association with the decrease in the mitochondrial transmembrane potentials (Δψ(m)), increase in Bax/Bcl-2 ratio, and activation of caspase-3. Cells treated with EAEER and HEMA generated intracellular reactive oxygen species (ROS) and nitric oxide (NO), indicating that ROS and RNS play important roles in the induction of apoptosis in B16F10 cells. Taken together, EAEER and its major bioactive compound, HEMA, inhibited the proliferation of B16F10 cells via apoptosis and may be a potential antimelanoma agent.

Inhibitory effects of resveratrol on the Epstein-Barr virus lytic cycle.

Reactivation of Epstein-Barr virus (EBV) from latency to the lytic cycle is required for the production of viral particles. Here, we examine the capacity of resveratrol to inhibit the EBV lytic cycle. Our results show that resveratrol inhibits the transcription of EBV immediate early genes, the expression of EBV lytic proteins, including Rta, Zta, and EA-D and reduces viron production, suggesting that this compound may be useful for preventing the proliferation of the virus.

Activation of the promoter of the fengycin synthetase operon by the UP element.

Bacillus subtilis F29-3 produces an antifungal peptidic antibiotic that is synthesized nonribosomally by fengycin synthetases. Our previous work established that the promoter of the fengycin synthetase operon is located 86 nucleotides upstream of the translational initiation codon of fenC. This investigation involved transcriptional fusions with a DNA fragment that contains the region between positions -105 and +80 and determined that deleting the region between positions -55 and -42 reduces the promoter activity by 64.5%. Transcriptional fusions in the B. subtilis DB2 chromosome also indicated that mutating the sequence markedly reduces the promoter activity. An in vitro transcription analysis confirmed that the transcription is inefficient when the sequence in this region is mutated. Electrophoretic mobility shift and footprinting analyses demonstrated that the C-terminal domain of the RNA polymerase alpha subunit binds to the region between positions -55 and -39. These results indicated that the sequence is an UP element. Finally, this UP element is critical for the production of fengycin, since mutating the UP sequence in the chromosome of B. subtilis F29-3 reduces the transcription of the fen operon by 85% and prevents the cells from producing enough fengycin to suppress the germination of Paecilomyces variotii spores on agar plates.

Inhibition of the epstein-barr virus lytic cycle by andrographolide.

Andrographis paniculata NEES is a medicinal plant that is commonly used in Asia. This work demonstrates that 25 microg/ml of ethanolic extract from A. paniculata (EEAP) and 5 microg/ml of andrographolide, a bioactive compound in EEAP, effectively inhibit the expression of Epstein-Barr virus (EBV) lytic proteins, Rta, Zta and EA-D, during the viral lytic cycle in P3HR1 cells. Transient transfection analysis revealed that the lack of expression of Rta, Zta and EA-D is caused by the inhibition of the transcription of BRLF1 and BZLF1, two EBV immediate-early genes that encode Rta and Zta, respectively. This study finds that the inhibition prevents the virus from producing mature viral particles. Meanwhile, andrographolide is not toxic to P3HR1 cells when the concentration is below 5 microg/ml, indicating that the compound is potentially useful as an anti-EBV drug.

Extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes among clinical isolates of Escherichia coli and Klebsiella pneumoniae from seven medical centers in Taiwan.

Production of extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes was investigated among 291 Escherichia coli and 282 Klebsiella pneumoniae isolates that showed decreased susceptibilities to extended-spectrum cephalosporins from seven Taiwanese medical centers. CTX-M-type and SHV-type enzymes were the most prevalent extended-spectrum beta-lactamases. CMY-2-like and DHA-1-like beta-lactamases were the most prevalent AmpC-type enzymes.

Functional analysis of fengycin synthetase FenD.

Fengycin is a cyclic lipopeptidic antibiotic produced nonribosomally by Bacillus subtilis. A fengycin synthetase mutant of B. subtilis F29-3 was generated with Tn917lux, which contains a transposon inserted in a 7716-bp gene, fenD. The mutation can be genetically complemented by transforming a plasmid carrying a wild-type fenD, confirming the participation of the gene in fengycin synthesis. Sequencing and biochemical analysis reveal that this gene encodes an enzyme that includes two amino acid-activating modules, FenD1 and FenD2, which activate l-Tyr and l-Thr, the third and the fourth amino acids in fengycin, respectively.