A Bufadienolide-Enriched Fraction of Bryophyllum pinnatum Inhibits Human Myometrial Contractility In Vitro

Planta Medica ◽  
2018 ◽  
Vol 85 (05) ◽  
pp. 385-393 ◽  
Author(s):  
Stefanie Santos ◽  
Christian Haslinger ◽  
Kristian Klaic ◽  
Maria Faleschini ◽  
Mónica Mennet ◽  
...  
Keyword(s):  
Cell Viability ◽  
Area Under The Curve ◽  
Progressive Increase ◽  
Human Myometrium ◽  
Organ Bath ◽  
Relaxant Effect ◽  
System Cell ◽  
Myometrial Contractility ◽  
Bryophyllum Pinnatum

Abstract Bryophyllum pinnatum has been used since the 1970s to prevent premature labour, first in anthroposophic hospitals and, more recently, also in the main Swiss perinatal centres. However, it is not known which compounds in B. pinnatum leaves contribute to the tocolytic effect. Here we studied the effects of a flavonoid-enriched fraction, the corresponding flavonoid aglycon mixture, a bufadienolide-enriched fraction, and B. pinnatum leaf press juice on human myometrial contractility in vitro. The strength (area under the curve and amplitude) and frequency of contractions were recorded using strips of human myometrium mounted in an organ bath system. Cell viability assays were performed with the human myometrium hTERT-C3 and PHM1 – 41 cell lines. Repeated addition of the flavonoid-enriched fraction, flavonoid aglycon mixture, bufadienolide-enriched fraction, or B. pinnatum leaf press juice led to a progressive decrease of contraction strength, without jeopardising the vitality of myometrium strips. The bufadienolide-enriched fraction was the most active, since 1 µg/mL of the bufadienolide-enriched fraction lowered the area under the curve to 40.1 ± 11.8% of the initial value, whereas 150 µg/mL of the flavonoid-enriched fraction, 6.2 µg/mL of the flavonoid aglycon mixture, and 10 µg/mL of the B. pinnatum leaf press juice were required to achieve comparable inhibition. A progressive increase of contraction frequency was observed, except in the case of the flavonoid aglycon mixture, which did not affect frequency. None of the test substances decreased myometrial cell viability, even at concentrations of 500 µg/mL of the flavonoid-enriched fraction, 40 µg/mL of the flavonoid aglycon mixture, 3.8 µg/mL of the bufadienolide-enriched fraction, and 75 µg/mL of the B. pinnatum leaf press juice, i.e., higher than those used in the myometrium experiments. Given the concentrations of flavonoids in the flavonoid-enriched fraction and B. pinnatum leaf press juice, and of bufadienolides in the bufadienolide-enriched fraction and B. pinnatum leaf press juice, it appears that bufadienolides may be mainly responsible for the relaxant effect.

scholarly journals Bryophyllum pinnatum enhances the inhibitory effect of atosiban and nifedipine on human myometrial contractility: an in vitro study

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
S. Santos ◽  
C. Haslinger ◽  
M. Mennet ◽  
U. von Mandach ◽  
M. Hamburger ◽  
...  
Keyword(s):  
Cell Viability ◽  
Therapeutic Potential ◽  
Inhibitory Effect ◽  
Human Myometrium ◽  
Anthroposophic Medicine ◽  
Organ Bath ◽  
Amplitude Data ◽  
Myometrial Contractility ◽  
Bryophyllum Pinnatum

Abstract Background The herbal medicine Bryophyllum pinnatum has been used as a tocolytic agent in anthroposophic medicine and, recently, in conventional settings alone or as an add-on medication with tocolytic agents such as atosiban or nifedipine. We wanted to compare the inhibitory effect of atosiban and nifedipine on human myometrial contractility in vitro in the absence and in the presence of B. pinnatum press juice (BPJ). Methods Myometrium biopsies were collected during elective Caesarean sections. Myometrial strips were placed under tension into an organ bath and allowed to contract spontaneously. Test substances alone and at concentrations known to moderately affect contractility in this setup, or in combination, were added to the organ bath, and contractility was recorded throughout the experiments. Changes in the strength (measured as area under the curve (AUC) and amplitude) and frequency of contractions after the addition of all test substances were determined. Cell viability assays were performed with the human myometrium hTERT-C3 and PHM1–41 cell lines. Results BPJ (2.5 μg/mL), atosiban (0.27 μg/mL), and nifedipine (3 ng/mL), moderately reduced the strength of spontaneous myometrium contractions. When BPJ was added together with atosiban or nifedipine, inhibition of contraction strength was significantly higher than with the tocolytics alone (p = 0.03 and p < 0.001, respectively). In the case of AUC, BPJ plus atosiban promoted a decrease to 48.8 ± 6.3% of initial, whereas BPJ and atosiban alone lowered it to 70.9 ± 4.7% and to 80.9 ± 4.1% of initial, respectively. Also in the case of AUC, BPJ plus nifedipine promoted a decrease to 39.9 ± 4.6% of initial, at the same time that BPJ and nifedipine alone lowered it to 78.9 ± 3.8% and 71.0 ± 3.4% of initial. Amplitude data supported those AUC data. The inhibitory effects of BPJ plus atosiban and of BPJ plus nifedipine on contractions strength were concentration-dependent. None of the test substances, alone or in combination, decreased myometrial cell viability. Conclusions BPJ enhances the inhibitory effect of atosiban and nifedipine on the strength of myometrial contractions, without affecting myometrium tissue or cell viability. The combination treatment of BPJ with atosiban or nifedipine has therapeutic potential.

In Vitro Comparative Effect of Carbetocin and Oxytocin in Pregnant Human Myometrium with and without Oxytocin Pretreatment

2016 ◽  
Vol 124 (2) ◽  
pp. 378-386 ◽  
Author(s):  
Naida M. Cole ◽  
Jose C. A. Carvalho ◽  
Magda Erik-Soussi ◽  
Nivetha Ramachandran ◽  
Mrinalini Balki
Keyword(s):  
Dose Response ◽  
Salt Solution ◽  
Area Under The Curve ◽  
Primary Outcome Measure ◽  
Human Myometrium ◽  
Control Group ◽  
Organ Bath ◽  
Motility Index ◽  
Elective Cesarean

Abstract Background The purpose of this study was to compare in vitro contractile effects of oxytocin and carbetocin on human term pregnant myometrium with and without oxytocin pretreatment. Methods This laboratory investigation was conducted on myometrial samples from women undergoing elective cesarean deliveries. The samples were dissected into four strips and suspended in individual organ bath chambers containing physiologic salt solution. After equilibration, they were pretreated with oxytocin 10−5 M (experimental group) or physiologic salt solution (control group) for 2 h and then subjected to dose–response testing with increasing concentrations of oxytocin or carbetocin (10−10 to 10−5 M). The amplitude, frequency, motility index (amplitude × frequency), and area under the curve of contractions were recorded and analyzed during the equilibration and dose–response periods. Comparisons were made between oxytocin-induced and carbetocin-induced contractions in control and oxytocin-pretreated groups. Motility index was the primary outcome measure. Results Sixty-three experiments were performed (carbetocin, n = 31; oxytocin, n = 32) on samples from 18 women. The motility index of contractions (√g.contractions/10 min) produced by oxytocin was significantly higher than carbetocin in both control (regression-estimated difference, 0.857; 95% CI, 0.290 to 1.425; P = 0.003) and oxytocin-pretreated (0.813; 0.328 to 1.299; P = 0.001) groups. The motility index was significantly lower in oxytocin-pretreated groups than their respective controls for both oxytocin (−1.040; −1.998 to −0.082; P = 0.03) and carbetocin (−0.996; −1.392 to −0.560; P &lt; 0.001). Conclusions In vitro contractions produced by oxytocin are superior to carbetocin in human myometrium with or without oxytocin pretreatment. Oxytocin pretreatment results in attenuation of contractions induced by both oxytocin and carbetocin.

In vitro effect on myometrial contractility by a combination of Bryophyllum pinnatum juice and atosiban

2017 ◽  
Author(s):  
S Santos ◽  
C Haslinger ◽  
M Hamburger ◽  
M Mennet ◽  
O Potterat ◽  
...  
Keyword(s):  
Myometrial Contractility ◽  
Vitro Effect ◽  
Bryophyllum Pinnatum

A -enriched fraction of Bryophyllum pinnatum inhibits human myometrial contractility in vitro

2019 ◽  
Author(s):  
S Santos ◽  
C Haslinger ◽  
K Kalic ◽  
MT Faleschini ◽  
M Mennet ◽  
...  
Keyword(s):  
Myometrial Contractility ◽  
Bryophyllum Pinnatum

scholarly journals Influence of oxytocin receptor single nucleotide sequence variants on contractility of human myometrium: an in vitro functional study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
F. Füeg ◽  
S. Santos ◽  
C. Haslinger ◽  
B. Stoiber ◽  
L. Schäffer ◽  
...  
Keyword(s):  
Mode Of Delivery ◽  
Oxytocin Receptor ◽  
Functional Study ◽  
Human Myometrium ◽  
Sequence Variants ◽  
Organ Bath ◽  
Single Nucleotide ◽  
Allele Distribution ◽  
Stimulation Of

Abstract Background Oxytocin receptor (OXTR) gene variants have been shown to affect the prevalence of preterm birth, mode of delivery and oxytocin (OXT) requirements for labor induction and augmentation. We hypothesized that this might be associated with different myometrium responses to oxytocin. Our aim was to investigate the influence of a selection of eight OXTR gene single nucleotide variants on oxytocin-induced stimulation of human myometrium contractility in vitro. Methods Human myometrium biopsies were collected during elective cesarean sections at term, if patients had given informed consent. Myometrial strips were submerged under tension in an organ bath and allowed to contract; the remaining material was stored at − 80 °C for further determination of relevant genetics and mRNA level. The area under the curve (AUC) of all contractions taking place in the absence of OXT and of those occurring upon OXT addition (for 30 min each) was measured. OXT stimulation, defined as the ratio between AUC measurements after OXT addition and those in the absence of OXT was calculated for each strip. TaqMan™ Assays were used to detect the allele distribution of the eight OXTR variants and to determine the relative amounts of OXTR-mRNA in the samples. For each variant, oxytocin stimulation of contractility was compared between samples homozygous for the reference allele (reference group) and samples with at least one variant allele (variant group) by linear regression. Results Sixty samples were included in the present study. For rs1042778, rs11706648, rs4686301, rs53576, rs237895, and rs237902, OXT stimulation was similar in the reference and in the variant groups. However, the values of OXT stimulation differed significantly between the reference and the variant groups for rs4686302 (3.1 vs. 4.1 times; p = 0.022) and rs237888 (3.2 vs. 5.5 times; p = 0.001). No significant differences between the levels of OXTR-mRNA in the various reference and corresponding variant groups were detected. Conclusions Patients with variant alleles of rs237888 and/or rs4686302 may be more sensitive to oxytocin stimulation, explaining why these sequence variants have been associated with lower cesarean section prevalence and premature birth, respectively.

scholarly journals In Vitro Effects of Propofol on Gravid Human Myometrium

2008 ◽  
Vol 36 (6) ◽  
pp. 802-806 ◽  
Author(s):  
A. S. Thind ◽  
R. J. Turner
Keyword(s):  
Isometric Tension ◽  
Human Myometrium ◽  
Organ Bath ◽  
Dependent Manner ◽  
Uterine Contractility ◽  
Time Curve ◽  
Lower Segment Caesarean Section ◽  
Uterine Muscle ◽  
In Vitro Effects

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle. Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 × 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5°C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer. Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 /μg/ml, 5 /μg/ml and 8 /μg/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 μ/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 ± 6.5% of control at 2 μg/ml 53±4.3% at 5 μ/ml and 45 ± 4.1% at 8 μg/ml. This decrease in contractility was statistically significant at concentrations >2 μg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner.

scholarly journals Effect of dual tocolysis with fenoterol and atosiban in human myometrium

2019 ◽  
Vol 47 (2) ◽  
pp. 190-194 ◽  
Author(s):  
Bernhard Stoiber ◽  
Christian Haslinger ◽  
Marie Kristin Schäffer ◽  
Roland Zimmermann ◽  
Leonhard Schäffer
Keyword(s):  
Area Under The Curve ◽  
Antagonistic Effect ◽  
Additive Effect ◽  
University Hospital ◽  
Rank Test ◽  
Human Myometrium ◽  
Tissue Samples ◽  
Significant Difference ◽  
Signed Rank Test

Abstract Objectives To measure the tocolytic effect of the combination of the oxytocin receptor antagonist atosiban with the β-mimetic agent fenoterol on human myometrium of pregnant women. Methods An in vitro study of contractility in human myometrium at the Laboratory of the Department of Obstetrics, University Hospital of Zürich, Switzerland, was performed. Thirty-six human myometrial biopsies were obtained during elective caesarean sections of singleton pregnancies at term. Tissue samples were exposed to atosiban, fenoterol and the combination of atosiban with fenoterol. Contractility was measured as area under the curve during 30 min of spontaneous contractions. The effect of treatment was expressed as the percentage of change from basal activity during 30 min of exposure. Differences were calculated using a paired Wilcoxon signed-rank test. An additive effect of dual tocolysis was assumed when no significant difference was detected between the observed and expected inhibition of dual tocolysis. When inhibition was greater or lower than expected, the dual combination was characterised as “synergistic” or “antagonistic”, respectively. Results Atosiban and fenoterol alone suppressed contractions by a median of 43.2% and 29.8%, respectively. The combination of atosiban plus fenoterol was measured at a level of 67.3% inhibition. There was no significant difference in the expected (63.2%) and observed inhibition effect of dual tocolysis (P=0.945). Conclusion This study demonstrated an additive effect of dual tocolysis of atosiban and fenoterol on human myometrium in vitro, but no synergistic or antagonistic effect.

Contribution of coupling between human myometrial β2-adrenoreceptor and the BKCa channel to uterine quiescence

2004 ◽  
Vol 287 (6) ◽  
pp. C1747-C1752 ◽  
Author(s):  
Boonsri Chanrachakul ◽  
Fiona Broughton Pipkin ◽  
Raheela N. Khan
Keyword(s):  
Protein Interactions ◽  
Therapeutic Potential ◽  
Human Myometrium ◽  
Bkca Channel ◽  
Protein Protein Interactions ◽  
Relaxant Effect ◽  
Functional Correlation ◽  
Myometrial Contractility ◽  
Uterine Relaxation ◽  
Insight Into

The β2-adrenergic receptor (β2-AR) and the large-conductance Ca2+-activated K+ (BKCa) channel have been shown, separately, to be involved in mediating uterine relaxation. Our recent studies reveal that the levels of both β2-AR and BKCa channel proteins in pregnant human myometrium decrease by ∼50% after the onset of labor. We present direct evidence in support of a structural and functional association between the β2-AR and the BKCa channel in pregnant human myometrium. Localization of both proteins is predominantly plasmalemmal, with 60% of β2-AR colocalizing with the BKCa channel. Coimmunoprecipitation studies indicate that BKCa and β2-AR are structurally linked by direct protein-protein interactions. Functional correlation was confirmed by experiments of human myometrial contractility in which the BKCa channel blocker, paxilline, significantly antagonized the relaxant effect of the β2-AR agonist ritodrine. These novel findings provide an insight into the coupling between the β2-AR and BKCa channel and may have utility in the application of this signaling cascade for therapeutic potential in the management of preterm labor.

Stew in its Own Juice: Protein Homeostasis Machinery Inhibition Reduces Cell Viability in Multiple Myeloma Cell Lines

2019 ◽  
Vol 19 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Mariana B. de Oliveira ◽  
Luiz F.G. Sanson ◽  
Angela I.P. Eugenio ◽  
Rebecca S.S. Barbosa-Dantas ◽  
Gisele W.B. Colleoni
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Cell Viability ◽  
Cell Lines ◽  
Treatment Options ◽  
Compensatory Mechanism ◽  
Protein Homeostasis ◽  
Protein Response ◽  
Rpmi 8226

Introduction:Multiple myeloma (MM) cells accumulate in the bone marrow and produce enormous quantities of immunoglobulins, causing endoplasmatic reticulum stress and activation of protein handling machinery, such as heat shock protein response, autophagy and unfolded protein response (UPR).Methods:We evaluated cell lines viability after treatment with bortezomib (B) in combination with HSP70 (VER-15508) and autophagy (SBI-0206965) or UPR (STF- 083010) inhibitors.Results:For RPMI-8226, after 72 hours of treatment with B+VER+STF or B+VER+SBI, we observed 15% of viable cells, but treatment with B alone was better (90% of cell death). For U266, treatment with B+VER+STF or with B+VER+SBI for 72 hours resulted in 20% of cell viability and both treatments were better than treatment with B alone (40% of cell death). After both triplet combinations, RPMI-8226 and U266 presented the overexpression of XBP-1 UPR protein, suggesting that it is acting as a compensatory mechanism, in an attempt of the cell to handle the otherwise lethal large amount of immunoglobulin overload.Conclusion:Our in vitro results provide additional evidence that combinations of protein homeostasis inhibitors might be explored as treatment options for MM.

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