In vitro activity of mastoparan-AF alone and in combination with clinically used antibiotics against multiple-antibiotic-resistant Escherichia coli isolates from animals

Lin, Chun-Ching; Hou, Roger F.; Shyu, Ching-Lin; Shia, Wei-Yau; Lin, Chuen‐Fu; Tu, Wu‐Chun

doi:10.1016/j.peptides.2012.03.002

Cited by 22 publications

(20 citation statements)

References 50 publications

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“…Stimulation of PLC has been described previously (3) for rat mast cells and hepatocytes and human HL-60 leukaemia cells, whereas inhibition of PLC has been found for SH-SY5Y human neuro-blastoma cells and human astrocytoma cells (3). Results of recent studies have indicated that there is a possibility of stimulation of programmable cell death in various types of cells (4)(5)(6).…”

Section: Introductionmentioning

confidence: 92%

Effect of pertussis toxin on calcium influx in three contraction models

et al. 2014

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Abstract. Pertussis toxin (PTX) blocks G protein activation and inhibits signal transmission from the activated receptor to effectors that are specific for the G protein-coupled receptor. The aim of the present study was to evaluate the effect of PTX on vascular smooth muscle cells that were stimulated pharmacologically with phenylephrine (α-adrenoceptor agonist), mastoparan-7 (direct G-protein activator) and Bay K8644 (direct calcium channel activator). The changes in perfusion pressure that were proportional to the degree of phenylephrine-induced constriction of rat tail arteries were assessed. Concentration-response curves (CRCs) that were obtained for phenylephrine, mastoparan-7 and Bay K8644 presented a sigmoidal association. A significantly reduced calcium influx to the cytoplasm in the presence of mastoparan-7 resulted in a significant rightward shift of the CRCs with a significant reduction in maximal responses. The presence of PTX did not change mastoparan-7 and Bay K8644-induced contraction, whereas the significant inhibition of phenylephrine-induced contraction was found. The results of the experiments indicated that PTX significantly inhibited phenylephrine-induced contraction of vascular smooth muscle cells by inhibition of calcium influx from the intra-and extracellular calcium space. PTX did not change the smooth muscle contraction that was induced by mastoparan-7 and Bay K8644. The predominant effect of mastoparan-7 may be associated with other binding sites as compared to the G-protein or PTX may bind to other sites than mastoparan-7.

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Section: Introductionmentioning

confidence: 92%

Effect of pertussis toxin on calcium influx in three contraction models

et al. 2014

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“…Polycationic a-helical peptides have been reported to exhibit synergistic effects by enhancing the uptake of some antibiotics. [9][10][11][12][13][14][15] Small cationic cyclic peptides from the polymycin family have also been shown to exhibit synergy with small hydrophobic antibiotics. [16] Therefore, these cationic cyclooctapeptides, in their fast acting capacity to compromise the integrity of bacterial membranes, could present themselves as valuable synergists by enhancing the uptake of some antibiotics.…”

Section: Time Course Assaymentioning

confidence: 99%

“…[9][10][11][12][13] For example, recently Zhang et al reported in vitro synergistic activities of brevinin-2CE in combination with five kinds of antibiotics against clinical isolates of extended-spectrum b-lactamase producing E. coli and methicillin-resistant S. aureus. [14] Anti-methicillin-resistant S. aureus activity of mouse b-defensin 3 in combination with ampicillin has also shown synergism.…”

Section: Introductionmentioning

confidence: 99%

In Vitro Synergy Between Some Cationic Amphipathic Cyclooctapeptides and Antibiotics

et al. 2015

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The antimicrobial activities of some cationic amphipathic cyclooctapeptides in combination with select antibiotics are investigated. Accordingly, cyclooctapeptides (CPs 1-11) derived from the sequence cyclo[Leu-D-Leu-Leu-D-Leu-Lys-DLys-Lys-D-Lys] were tested against Escherichia coli and Staphylococcus aureus. Synergistic effects were evaluated in combination with tetracycline, chloramphenicol, oflaxacin, rifampicin, colistin, clindamycin, and vancomycin by the checkerboard titration assay. The results show that these cyclooctapeptides are fast acting bactericidals and are comparable to the related a-helical peptides in their activities. Significantly, some of these cyclooctapeptides exert selective synergistic effects in combination with the bacteriostatic tetracycline against S. aureus; a greater than 4-fold decrease in the minimum inhibition concentration was observed. Their synergism with the other evaluated antibiotics was generally partial or additive. Cationic amphipathic cyclooctapeptides in combination with some antibiotics could offer a possible solution to the increasing antimicrobial resistance predicament.

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“…By contrast, the inhibition of PLC by mastoparan has been demonstrated in SH-SY5Y human neuroblastoma cells and in human astrocytoma cells (1). Recent studies suggested the possibility of programmed cell death stimulation in different types of cells (2)(3)(4).…”

Section: Introductionmentioning

confidence: 99%

Direct regulation of vascular smooth muscle contraction by mastoparan-7

et al. 2013

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Abstract. Mastoparan-7 (mas-7) is a basic tetradecapeptide isolated from wasp venom, which activates guanine nucleotide-binding regulatory proteins (G-proteins) and stimulates apoptosis. In smooth muscle cells, mas-7 leads to an increase in the perfusion pressure. The main aim of this study was to evaluate the physiological effect of the direct stimulation of G-proteins in comparison to the typical stimulation of receptors in vascular smooth muscle cells (VSMCs). Experiments were performed on the isolated and perfused tail artery of Wistar rats. The contraction force in our model was measured by an increased level of perfusion pressure with a constant flow. The concentration response curves (CRCs) obtained for mas-7 were sigmoidal. In comparison to the curves for phenylephrine and vasopressin, the mas-7 curve was significantly shifted to the right with a significant reduction in maximal response. Mas-7 significantly increased the perfusion pressure for the intra-and extracellular calcium (Ca 2+ ) influx to the cytoplasm. The presence of the pertussis toxin (PT) did not affect the mas-7-induced contraction. In comparison to phenylephrine and vasopressin, all the values of perfusion pressure following stimulation of the G-proteins by mas-7 were significantly lower. The results of our experiments suggested that mas-7 significantly induces the contraction of VSMCs. The binding site for mas-7 is different from that for PT; thus, PT does not affect VSMC contraction. The tissue effect of this stimulation is comparable to the stimulatory effect of partial agonists. Current knowledge regarding the apoptosis pathway reveals the significance of Ca 2+ ions involved in this process. Therefore, mas-7 may induce apoptosis through an increase in the cytoplasmic Ca 2+ concentration; however, the use of this mechanism in anticancer therapy must be preceded by a molecule modification that eliminates the vasoconstrictive effect.

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In vitro activity of mastoparan-AF alone and in combination with clinically used antibiotics against multiple-antibiotic-resistant Escherichia coli isolates from animals

Cited by 22 publications

References 50 publications

Effect of pertussis toxin on calcium influx in three contraction models

Effect of pertussis toxin on calcium influx in three contraction models

In Vitro Synergy Between Some Cationic Amphipathic Cyclooctapeptides and Antibiotics

Direct regulation of vascular smooth muscle contraction by mastoparan-7

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