Taurolidine Acts on Bacterial Virulence Factors and Does Not Induce Resistance in Periodontitis-Associated Bacteria—An In-Vitro Study

The aims of the present study were: (a) to determine the mechanism of action of taurolidine against bacterial species associated with periodontal disease, and (b) to evaluate the potential development of resistance against taurolidine as compared with minocycline. After visualizing the mode of action of taurolidine by transmission electron micrographs, the interaction with most important virulence factors (lipopolysaccharide (LPS), Porphyromonas gingivalis gingipains, Aggregatibacter actinomycetemcomitans leukotoxin), was analyzed. Then, 14 clinical isolates from subgingival biofilm samples were transferred on agar plates containing subinhibitory concentrations of taurolidine or minocycline up to 50 passages. Before and after each 10 passages, minimal inhibitory concentrations (MICs) were determined. Increasing MICs were screened for efflux mechanism. Taurolidine inhibited in a concentration-dependent manner the activities of LPS and of the arginine-specific gingipains; however, an effect on A. actinomycetemcomitans leukotoxin was not detected. One P. gingivalis strain developed a resistance against taurolidine, which was probably linked with efflux mechanisms. An increase of MIC values of minocycline occurred in five of the 14 included strains after exposure to subinhibitory concentrations of the antibiotic. The present results indicate that: (a) taurolidine interacts with LPS and gingipains, and (b) development of resistance seems to be a rare event when using taurolidine.

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Activity of taurolidine on species associated with periodontitis

10.21203/rs.2.13864/v1 ◽

2019 ◽

Author(s):

Sabrina Radakovic ◽

Simon Schmid ◽

Nicola Andreoli ◽

Sandor Nietzsche ◽

Jürg Zumbrunn ◽

...

Keyword(s):

Cell Wall ◽

Mode Of Action ◽

Bacterial Species ◽

Rare Event ◽

Dependent Manner ◽

Oral Streptococci ◽

Concentration Dependent Manner ◽

Development Of Resistance ◽

Potential Development ◽

Subinhibitory Concentrations

Abstract Background Taurolidine is thought to be an alternative antimicrobial in periodontal therapy. The purpose of this follow-up taurolidine study was to determine in more detail the mode of action of taurolidine against bacterial species being associated with periodontal disease. Further, a potential development of resistance against taurolidine in comparison with minocycline was to evaluate. Results Visualizing the mode of action of taurolidine to Porphyromonas gingivalis by scanning and transmission electron micrographs showed in part pores and release of constituents from the cell wall. The interaction of taurolidin with bacterial cell wall is also supported by the finding that taurolidine inhibited in a concentration-dependent manner the activities of LPS and of the P. gingivalis arginine-specific gingipains. However, an effect on A. actinomycetemcomitans leukotoxin was not found. When transferring 14 clinical isolates from subgingival biofilm samples (4 P. gingivalis, 2 A. actinomycetemcomitans, 2 Tannerella forsythia, 2 Fusobacterium nucleatum, 4 oral streptococci) on agar plates containing subinhibitory concentrations of taurolidine up to 50 passages, one P. gingivalis strain developed a resistance against taurolidine which was probably linked with efflux mechanisms. When antimicrobial pressure was removed, MIC reverted to baseline value. Testing development of resistance to minocycline in a similar way, an increase of MIC values occurred in five of the 14 included strains after exposure to subinhibitory concentrations of the antibiotic. Efflux might play a role in one A. actinomycetemcomitans strains, but obviously not in the other four strains. Removing antimicrobial pressure for a few passages did not revert the increased MIC values. Conclusion Taurolidine interacts with LPS and gingipains. Development of resistance seems to be a rare event when applying taurolidine. A potential development of resistance might be associated with efflux mechanisms.

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Taurolidine acts on bacterial virulence factors and does not induce resistance in periodontitis-associated bacteria

10.21203/rs.2.13864/v2 ◽

2019 ◽

Author(s):

Sabrina Radakovic ◽

Simon Schmid ◽

Nicola Andreoli ◽

Sandor Nietzsche ◽

Jürg Zumbrunn ◽

...

Keyword(s):

Cell Wall ◽

Mode Of Action ◽

Bacterial Species ◽

Rare Event ◽

Dependent Manner ◽

Oral Streptococci ◽

Concentration Dependent Manner ◽

Development Of Resistance ◽

Potential Development ◽

Subinhibitory Concentrations

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Human Neuronal Cell Lines as An In Vitro Toxicological Tool for the Evaluation of Novel Psychoactive Substances

International Journal of Molecular Sciences ◽

10.3390/ijms22136785 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6785

Author(s):

Valeria Sogos ◽

Paola Caria ◽

Clara Porcedda ◽

Rafaela Mostallino ◽

Franca Piras ◽

...

Keyword(s):

Cell Death ◽

Neuronal Cell ◽

In Vitro Study ◽

Dependent Manner ◽

Novel Psychoactive Substances ◽

Psychoactive Substances ◽

Concentration Dependent Manner ◽

Mechanisms Of Toxicity ◽

Neuronal Cell Lines

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.

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The Modulation of PCSK9 and LDLR by Supercritical CO2 Extracts of Mentha longifolia and Isolated Piperitone Oxide, an In Vitro Study

Molecules ◽

10.3390/molecules26133886 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3886

Author(s):

Stefania Sut ◽

Irene Ferrarese ◽

Maria Giovanna Lupo ◽

Nicola De Zordi ◽

Elisa Tripicchio ◽

...

Keyword(s):

Mass Spectrometry ◽

Cell Lines ◽

Hepatoma Cell ◽

Density Lipoprotein ◽

In Vitro Study ◽

Volatile Constituent ◽

Dependent Manner ◽

Human Hepatoma Cell ◽

Concentration Dependent Manner

In the present study the ability of supercritical carbon dioxide (SCO2) extracts of M. longifolia L. leaves to modulate low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) expression was evaluated in cultured human hepatoma cell lines Huh7 and HepG2. Two SCO2 extracts, one oil (ML-SCO2) and a semisolid (MW-SCO2), were subjected to detailed chemical characterization by mono- and bidimensional nuclear magnetic resonance (1D, 2D-NMR), gas chromatography coupled with mass spectrometry (GC-MS) and liquid chromatography coupled with mass spectrometry (LC-MS). Chemical analysis revealed significant amounts of fatty acids, phytosterols and terpenoids. ML-SCO2 was able to induce LDLR expression at a dose of 60 µg/mL in HuH7 and HepG2 cell lines. Furthermore, ML-SCO2 reduced PCSK9 secretion in a concentration-dependent manner in both cell lines. Piperitone oxide, the most abundant compound of the volatile constituent of ML-SCO2 (27% w/w), was isolated and tested for the same targets, showing a very effective reduction of PCSK9 expression. The overall results revealed the opportunity to obtain a new nutraceutical ingredient with a high amount of phytosterols and terpenoids using the SCO2 extraction of M. longifolia L., a very well-known botanical species used as food. Furthermore, for the first time we report the high activity of piperitone oxide in the reduction of PCSK9 expression.

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Thrombin activatable fibrinolysis inhibitor (TAFI) affects fibrinolysis in a plasminogen activator concentration-dependent manner

Thrombosis and Haemostasis ◽

10.1160/th03-06-0377 ◽

2004 ◽

Vol 91 (03) ◽

pp. 473-479 ◽

Cited By ~ 15

Author(s):

Ana Guimarães ◽

Dingeman Rijken

Keyword(s):

Plasminogen Activator ◽

In Vitro Study ◽

Inhibitory Effect ◽

Retardation Factor ◽

Clot Lysis ◽

Dependent Manner ◽

Plasma Clot ◽

Concentration Dependent Manner ◽

Plasmin Inhibitor

SummaryTAFIa was shown to attenuate fibrinolysis. In our in vitro study, we investigated how the inhibitory effect of TAFIa depended on the type and concentration of the plasminogen activator (PA). We measured PA-mediated lysis times of plasma clots under conditions of maximal TAFI activation by thrombin-thrombomodulin in the absence and presence of potato carboxypeptidase inhibitor. Seven different PAs were compared comprising both tPA-related (tPA, TNK-tPA, DSPA), bacterial PA-related (staphylokinase and APSAC) and urokinase-related (tcu-PA and k2tu-PA) PAs. The lysis times and the retardation factor were plotted against the PA concentration. The retardation factor plots were bell-shaped. At low PA concentrations, the retardation factor was low, probably due to the limited stability of TAFIa. At intermediate PA concentrations the retardation factor was maximal (3-6 depending on the PA), with TNK-tPA, APSAC and DSPA exhibiting the strongest effect. At high PA concentrations, the retardation factor was again low, possibly due to inactivation of TAFIa by plasmin or to a complete conversion of glu-plasminogen into lys-plasminogen. Using individual plasmas with a reduced plasmin inhibitor activity (plasmin inhibitor Enschede) the bell-shaped curve of the retardation factor shifted towards lower tPA and DSPA concentrations, but the height did not decrease. In conclusion, TAFIa delays the lysis of plasma clots mediated by all the plasminogen activators tested. This delay is dependent on the type and concentration of the plasminogen activator, but not on the fibrin specificity of the plasminogen activator. Furthermore, plasmin inhibitor does not play a significant role in the inhibition of plasma clot lysis by TAFI.

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Toxicity Effects of Methylene Blue on Rat Intervertebral Disc Annulus Fibrosus Cells

January 2018 - Pain Physician ◽

10.36076/ppj/2019.22.155 ◽

2019 ◽

Vol 2 (22.2) ◽

pp. 155-164

Author(s):

Liang Zhang

Keyword(s):

Methylene Blue ◽

Cell Apoptosis ◽

Annulus Fibrosus ◽

Caspase 3 ◽

In Vitro Study ◽

Collagen Type I ◽

Type I ◽

Dependent Manner ◽

Concentration Dependent Manner

Background: There is an increasing local application of methylene blue (MB) in the treatment of discogenic low back pain (LBP) and percutaneous transforaminal endoscopic discectomy (PTED) procedures. MB could generate DNA damage and induce apoptosis in different cell types; however, the effects of MB on intervertebral disc (IVD) annulus fibrosus (AF) cells are not clearly understood. Objective: The objective of this study was to investigate the effects of different concentrations of MB on rat AF cells in vitro. Study Design: This study used an experimental design. Setting: This research was conducted at the Orthopaedic Institute of the Clinical Medical College of Yangzhou University. Methods: AF cells were isolated and cultured with different concentrations of MB (0, 2, 20, and 200 μg/mL) and assessed to determine the possible cytotoxic effects of MB. The cell proliferation was detected by Cell Counting Kit-8 (CCK-8) assay. The inverted phase-contrast microscopy was used to perform morphological observation of apoptotic cells, and flow cytometry was used to measure the incidence of cell apoptosis. The mRNA and protein expression levels of apoptosis-associated genes (caspase-3, Bcl-2, and Bax) and other related genes (collagen type I, transforming growth factor β1 [TGF-β1], fibroblast growth factor [bFGF], and tissue inhibitor of metalloproteinase-1 [TIMP-1]) were analyzed by quantitative real-time PCR (RT-PCR) and Western blotting. Results: Our results indicated that MB reduced cell viability in a concentration- and timedependent manner. MB also induced marked AF cell apoptosis in a concentration-dependent manner observed by inverted phase-contrast microscopy, flow cytometry, and indicated by the increased expression of caspase-3. Both RT-PCR and Western blotting revealed significant upregulation of Bax and caspase-3 expression levels accompanied by decreased expression of Bcl2 in a concentration-dependent manner. Moreover, collagen type I, TGF-β1, bFGF, and TIMP-1 mRNA and protein levels were also found to be decreased by MB in a concentration-dependent manner. Limitations: Limitations of this study were the in vitro study design and lack of in vivo validation of the observed effects of MB on human IVD cells. Conclusions: Our results indicate that a high concentration of MB can not only inhibit proliferation and paracrine function of AF cells, but can also induce cell apoptosis in a concentration-dependent manner, suggesting that it is necessary to choose low concentrations of MB in practical application and limit the use of MB in the treatment of discogenic LBP to research protocols. Key words: Methylene blue, annulus fibrosus cell, proliferation, apoptosis, paracrine

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Panax notoginsengAttenuates Bleomycin-Induced Pulmonary Fibrosis in Mice

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/404761 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Kuen-Daw Tsai ◽

Shu-Mei Yang ◽

Jen-Chih Lee ◽

Ho-Yiu Wong ◽

Chuen-Ming Shih ◽

...

Keyword(s):

Animal Model ◽

Pulmonary Fibrosis ◽

Culture Media ◽

Chinese Herb ◽

In Vitro Study ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Macrophage Cells ◽

Anti Inflammatory

Panax notoginseng(PN) is a traditional Chinese herb experimentally proven to have anti-inflammatory effects, and it is used clinically for the treatment of atherosclerosis, cerebral infarction, and cerebral ischemia. This study aimed to determine the anti-inflammatory effects of PN against bleomycin-induced pulmonary fibrosis in mice. First, in an in vitro study, culture media containing lipopolysaccharide (LPS) was used to stimulate macrophage cells (RAW 264.7 cell line). TNF-αand IL-6 levels were then determined before and after treatment with PN extract. In an animal model (C57BL/6 mice), a single dose of PN (0.5 mg/kg) was administered orally on Day 2 or Day 7 postbleomycin treatment. The results showed that TNF-αand IL-6 levels increased in the culture media of LPS-stimulated macrophage cells, and this effect was significantly inhibited in a concentration-dependent manner by PN extract. Histopathologic examination revealed that PN administered on Day 7 postbleomycin treatment significantly decreased inflammatory cell infiltrates, fibrosis scores, and TNF-α, TGF-β, IL-1β, and IL-6 levels in bronchoalveolar lavage fluid when compared with PN given on Day 2 postbleomycin treatment. These results suggest that PN administered in the early fibrotic stage can attenuate pulmonary fibrosis in an animal model of idiopathic pulmonary fibrosis.

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Effect of Astaxanthin on the Expression and Activity of Aquaporin-3 in Skin in an In-Vitro Study

Life ◽

10.3390/life10090193 ◽

2020 ◽

Vol 10 (9) ◽

pp. 193

Author(s):

Nobutomo Ikarashi ◽

Risako Kon ◽

Chika Nagoya ◽

Airi Ishikura ◽

Yuri Sugiyama ◽

...

Keyword(s):

Water Channel ◽

In Vitro Study ◽

Expression Level ◽

Dependent Manner ◽

Hacat Cells ◽

Concentration Dependent Manner ◽

Aquaporin 3 ◽

Skin Function ◽

Skin Moisture

Astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione) is a red lipophilic pigment with strong antioxidant action. Oral or topical administration of astaxanthin has been reported to improve skin function, including increasing skin moisture. In this study, we examined the mechanism by which astaxanthin improves skin function by focusing on the water channel aquaporin-3 (AQP3), which plays important roles in maintaining skin moisture and function. When astaxanthin was added to PHK16-0b or HaCaT cells, the mRNA expression level of AQP3 increased significantly in a concentration-dependent manner in both cell lines. The AQP3 protein expression level was also confirmed to increase when astaxanthin was added to HaCaT cells. Similarly, when astaxanthin was added to 3D human epidermis model EpiSkin, AQP3 expression increased. Furthermore, when glycerol and astaxanthin were simultaneously added to EpiSkin, glycerol permeability increased significantly compared with that observed for the addition of glycerol alone. We demonstrated that astaxanthin increases AQP3 expression in the skin and enhances AQP3 activity. This result suggests that the increased AQP3 expression in the skin is associated with the increase in skin moisture by astaxanthin. Thus, we consider astaxanthin useful for treating dry skin caused by decreased AQP3 due to factors such as diabetes mellitus and aging.

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Gentamycin inhibition of kcl-induced contractions of myometrium isolated from non-pregnant and pregnant cows

Veterinární Medicína ◽

10.17221/5729-vetmed ◽

2012 ◽

Vol 49 (No. 11) ◽

pp. 401-405

Author(s):

H. Ocal ◽

M. Yuksel ◽

A. Ayar

Keyword(s):

Isometric Force ◽

In Vitro Study ◽

Displacement Transducer ◽

Ion Concentration ◽

Rank Test ◽

Organ Bath ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Signed Rank Test

The aim of this study was to investigate the effects of gentamycin on KCl-induced contractions of myometrium isolated from both non-pregnant and pregnant cows. Myometrial strips were isolated from non-pregnant and pregnant cows and suspended in a jacketed organ bath filled with Krebs’ solution at 37°C (pH 7.4) continuously bubbled with 95% oxygen and 5% carbon dioxide; isometric contractions were recorded using an isometric force displacement transducer. After manifestation of spontaneous contractions, KCl (60 mM) was applied to the bath and the effects of gentamycin (300 µM, 600 µM) on the amplitude (g) and frequency of KCl-induced contractions were evaluated in 10-minute intervals. Data were statistically analysed using Student’s t-test and Wilcoxon signed-rank test. Gentamycin inhibited the frequency and amplitude of KCl-induced contractions in a concentration dependent manner. At 300 µM and 600 µM, gentamycin significantly inhibited the amplitude and reduced the frequency of contractions of myometrium isolated from both pregnant and non-pregnant cows. However, an increase in the extracellular Ca<sup>+</sup> ion concentration virtually reversed this blockade. The results of this in vitro study indicate that gentamycin inhibits KCl-induced contractions of myometrium isolated from both non-pregnant and pregnant cows.

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Potential of Prebiotic D-Tagatose for Prevention of Oral Disease

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.767944 ◽

2021 ◽

Vol 11 ◽

Author(s):

Shota Mayumi ◽

Masae Kuboniwa ◽

Akito Sakanaka ◽

Ei Hashino ◽

Asuka Ishikawa ◽

...

Keyword(s):

Amino Acids ◽

Bacterial Species ◽

Viable Cell ◽

Oral Disease ◽

Dependent Manner ◽

Oral Streptococci ◽

Concentration Dependent Manner ◽

Carbohydrate Source ◽

Dental Biofilm

Recent studies have shown phenotypic and metabolic heterogeneity in related species including Streptococcus oralis, a typical oral commensal bacterium, Streptococcus mutans, a cariogenic bacterium, and Streptococcus gordonii, which functions as an accessory pathogen in periodontopathic biofilm. In this study, metabolites characteristically contained in the saliva of individuals with good oral hygiene were determined, after which the effects of an identified prebiotic candidate, D-tagatose, on phenotype, gene expression, and metabolic profiles of those three key bacterial species were investigated. Examinations of the saliva metabolome of 18 systemically healthy volunteers identified salivary D-tagatose as associated with lower dental biofilm abundance in the oral cavity (Spearman’s correlation coefficient; r = -0.603, p = 0.008), then the effects of D-tagatose on oral streptococci were analyzed in vitro. In chemically defined medium (CDM) containing D-tagatose as the sole carbohydrate source, S. mutans and S. gordonii each showed negligible biofilm formation, whereas significant biofilms were formed in cultures of S. oralis. Furthermore, even in the presence of glucose, S. mutans and S. gordonii showed growth suppression and decreases in the final viable cell count in a D-tagatose concentration-dependent manner. In contrast, no inhibitory effects of D-tagatose on the growth of S. oralis were observed. To investigate species-specific inhibition by D-tagatose, the metabolomic profiles of D-tagatose-treated S. mutans, S. gordonii, and S. oralis cells were examined. The intracellular amounts of pyruvate-derived amino acids in S. mutans and S. gordonii, but not in S. oralis, such as branched-chain amino acids and alanine, tended to decrease in the presence of D-tagatose. This phenomenon indicates that D-tagatose inhibits growth of those bacteria by affecting glycolysis and its downstream metabolism. In conclusion, the present study provides evidence that D-tagatose is abundant in saliva of individuals with good oral health. Additionally, experimental results demonstrated that D-tagatose selectively inhibits growth of the oral pathogens S. mutans and S. gordonii. In contrast, the oral commensal S. oralis seemed to be negligibly affected, thus highlighting the potential of administration of D-tagatose as an oral prebiotic for its ability to manipulate the metabolism of those targeted oral streptococci.

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