scholarly journals Mechanisms of P-Glycoprotein Modulation by Semen Strychni Combined with Radix Paeoniae Alba

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Li-Li Liu ◽  
Yong-Mei Guan ◽  
Xue-Ping Lu ◽  
Xin-Li Liang ◽  
Li-Hua Chen
Keyword(s):  
Atpase Activity ◽  
Cell Model ◽  
Chinese Herb ◽  
Therapeutic Window ◽  
Therapeutic Effects ◽  
Mrna Levels ◽  
P Glycoprotein ◽  
Mdr1 Mrna ◽  
Radix Paeoniae Alba ◽  
Semen Strychni

Semen Strychni has been extensively used as a Chinese herb, but its therapeutic window is narrowed by the strong toxicity of the compound, which limits its effectiveness. Radix Paeoniae Alba has been reported to reduce the toxic effects and increase the therapeutic effects of Semen Strychni, but the underlying mechanism remains unknown. This research aimed to explore the mechanism through which P-glycoprotein (P-gp) is modulated by Semen Strychni combined with Radix Paeoniae Alba in vitro. An MTT assay was used to study cytotoxicity in an MDCK-MDR1 cell model. Rh123 efflux and accumulation were measured to assess P-gp function. The expression levels of MDR1 mRNA and P-gp protein in MDCK-MDR1 cells were investigated. A P-gp ATPase activity assay kit was applied to detect the effect on P-gp ATPase activity. Semen Strychni combined with Radix Paeoniae Alba could induce P-gp-mediated drug transport by inhibiting brucine and strychnine transport in MDCK-MDR1 cells, enhancing the P-gp efflux function, upregulating the P-gp expression and MDR1 mRNA levels, and stimulating P-gp ATPase activity.

Paeoniflorin and albiflorin regulate P-gp-mediated aconitine and hypaconitine transport through an Madin Darby canine kidney-multi drug resistance protein 1 cell model

2021 ◽  
Vol 11 (8) ◽  
pp. 1394-1401
Author(s):  
Yun-Feng Liu ◽  
Yong-Mei Guan ◽  
Shi-Yu Huang ◽  
Lu Wu ◽  
Wei-Feng Zhu ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Cell Model ◽  
Multi Drug Resistance ◽  
Cytotoxic Effects ◽  
Transport Studies ◽  
Diphenyltetrazolium Bromide ◽  
Mdr1 Mrna ◽  
Attenuation Mechanism ◽  
Radix Aconiti ◽  
Radix Paeoniae Alba

Aconitine and hypaconitine are the main active ingredients of Radix Aconiti, paeoniflorin and albiflorin are the primary components of Radix Paeoniae Alba. Both Radix Aconiti and Radix Paeoniae Alba are herbs that are commonly used in traditional Chinese medicine. This study sought to explore the mechanistic transport of aconitine and hypaconitine across MDCK-MDR1 cells and to assess the effect of paeoniflorin and albiflorin on aconitine and hypaconitine transmembrane transport as a potential attenuation mechanism. Drug cytotoxicity was tested via the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and transport studies were performed in both directions. The effects of drugs on P-gp ATPase activity, P-gp efflux function, MDR1 mRNA and P-gp expression were evaluated in MDCK-MDR1 cells. Aconitine and hypaconitine treatment with the verapamil could significantly decrease the efflux rate (ER). The ER of aconitine and hypaconitine were significantly increased with the coadministration of paeoniflorin and albiflorin, suggesting that paeoniflorin and albiflorin can promote the efflux of these two alkaloids. Aconitine and hypaconitine can induce P-gp enzymatic activity, inhibit P-gp-mediated efflux, and downregulate the expression of P-gp protein to produce cytotoxic effects. When treatment in combination with paeoniflorin and albiflorin, it could stimulated P-gp ATPase activity, increasing mRNA expression, enhance P-gp efflux function, and upregulate P-gp protein expression.

scholarly journals Role of the highly structured 5′-end region of MDR1 mRNA in P-glycoprotein expression

2007 ◽  
Vol 406 (3) ◽  
pp. 445-455 ◽  
Author(s):  
Rebecca A. Randle ◽  
Selina Raguz ◽  
Christopher F. Higgins ◽  
Ernesto Yagüe
Keyword(s):  
Multidrug Resistance ◽  
Drug Exposure ◽  
Cytotoxic Drugs ◽  
Initiation Factor ◽  
Mrna Levels ◽  
Translational Repressor ◽  
P Glycoprotein ◽  
Mdr1 Mrna ◽  
Cytotoxic Stress

Overexpression of P-glycoprotein, encoded by the MDR1 (multidrug resistance 1) gene, is often responsible for multidrug resistance in acute myeloid leukaemia. We have shown previously that MDR1 (P-glycoprotein) mRNA levels in K562 leukaemic cells exposed to cytotoxic drugs are up-regulated but P-glycoprotein expression is translationally blocked. In the present study we show that cytotoxic drugs down-regulate the Akt signalling pathway, leading to hypophosphorylation of the translational repressor 4E-BP [eIF (eukaryotic initiation factor) 4E-binding protein] and decreased eIF4E availability. The 5′-end of MDR1 mRNA adopts a highly-structured fold. Fusion of this structured 5′-region upstream of a reporter gene impeded its efficient translation, specifically under cytotoxic stress, by reducing its competitive ability for the translational machinery. The effect of cytotoxic stress could be mimicked in vivo by blocking the phosphorylation of 4E-BP by mTOR (mammalian target of rapamycin) using rapamycin or eIF4E siRNA (small interfering RNA), and relieved by overexpression of either eIF4E or constitutively-active Akt. Upon drug exposure MDR1 mRNA was up-regulated, apparently stochastically, in a small proportion of cells. Only in these cells could MDR1 mRNA compete successfully for the reduced amounts of eIF4E and translate P-glycoprotein. Consequent drug efflux and restoration of eIF4E availability results in a feed-forward relief from stress-induced translational repression and to the acquisition of drug resistance.

Relation between MDR1 mRNA levels, resistance factor, and the efficiency of P-glycoprotein-mediated efflux of pirarubicin in multidrug-resistant K562 sublines

2002 ◽  
Vol 80 (11) ◽  
pp. 1054-1063 ◽  
Author(s):  
Jintana Meesungnoen ◽  
Jean-Paul Jay-Gerin ◽  
Samlee Mankhetkorn
Keyword(s):  
Prolonged Exposure ◽  
Multidrug Resistant ◽  
Resistance Factor ◽  
Cytotoxic Agents ◽  
Hill Coefficient ◽  
Mrna Levels ◽  
Experimental Conditions ◽  
P Glycoprotein ◽  
Mdr1 Mrna ◽  
Acidic Organelles

In this work, we sought to investigate the relation existing between MDR1 mRNA levels, the resistance factor (RF), and the efficiency of efflux of pirarubicin (THP) mediated by P-glycoprotein (P-gp) in multidrug-resistant (MDR) K562 sublines. The MDR K562 sublines were selected from K562/adr cells by exposure to different adriamycin concentrations: 300 nM (K562/300), 1000 nM (K562/1000), and 10 000 nM (K562/10000), yielding RF values of 23.2, 26.5, and 39.6, respectively. The analysis of the P-gp encoding MDR1 gene overexpression by reverse transcriptase – polymerase chain reaction provided evidence of increased MDR1 mRNA levels when the adriamycin concentration used for the MDR cell selection increased. We used spectrofluorometric methods to determine the kinetics of the uptake and P-gp-mediated efflux of THP in the different selected MDR K562 sublines. Our data showed that (i) the maximal rate of P-gp-mediated efflux of THP, Vmax, increased with increasing RF; (ii) the observed Michaelis constant, Km, had the same value for all selected sublines, thus leading to an overall increase in the ratio Vmax/Km (5.1 × 10–3, 6.2 × 10–3, 6.8 × 10–3, and 9.3 × 10–3 s–1 for K562/adr, K562/300, K562/1000, and K562/10000 cells, respectively), and (iii) the determination of the Hill coefficient (nH) gave values close to 2, which suggested a positive cooperative transport of THP with the expelling of two molecules of THP per turnover of P-gp. This study demonstrated that, in the K562/adr sublines used in our experiments, P-gp played a major role in conferring the MDR phenotype. Moreover, under our experimental conditions, intracellular acidic organelles were shown to contribute to decreased drug–target interaction and, thereby, decreased cytotoxicity. The variation of the concentrations of THP accumulated in the acidic organelles as a function of the total THP concentration added to the cells was the same, within the limits of experimental errors, whatever the degree of resistance of the studied MDR K562 sublines. Finally, this study suggested that, in the selected MDR K562 sublines, the K+/H+ antiporter exchanger could be activated by the pirarubicin transport, leading to a probable acidification of intracellular pH. The P-gp-mediated efflux of THP and an accumulation of THP in acidic organelles confer an advantage for MDR cells in surviving prolonged exposure to cytotoxic agents and giving rise to high degrees of resistance. Key words: multidrug resistance, P-glycoprotein, pirarubicin, acidic organelles, MDR1 mRNA levels, fluorescence spectroscopy, kinetic parameters.

scholarly journals Icariin protects against cage layer osteoporosis by intervening in steroid biosynthesis and glycerophospholipid metabolism

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhengwang Yu ◽  
Jie Huang ◽  
Zhongxin Zhou
Keyword(s):  
Metabolic Diseases ◽  
Chinese Herb ◽  
Therapeutic Effects ◽  
Mineral Density ◽  
Steroid Biosynthesis ◽  
Metabolic Pathway Analysis ◽  
Effective Prevention ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
Low Calcium

AbstractCage layer osteoporosis (CLO) is a common bone metabolism disease in the breeding industry of China. However, effective prevention for CLO has not been developed. Icariin (ICA), the main bioactive component of the Chinese herb Epimedium, has been shown to have good therapeutic effects on bone-related diseases. In this study, the effects of ICA were further evaluated in a low-calcium diet-induced CLO, and a serum metabolomics assay was performed to understand the underlying mechanisms. A total of 144 31-wk-old Lohmann pink-shell laying hens were randomly allocated to 4 groups with 6 replicates of 6 hens per replicate. The 4 dietary treatment groups consisted of a basal diet (3.5% calcium), a low-calcium diet (2.0% calcium), and a low-calcium diet supplemented with 0.5 or 2.0 g/kg ICA. The results showed that ICA exerted good osteoprotective effects on low-calcium diet-induced CLO. ICA significantly increased femur bone mineral density, improved bone microstructure, decreased bone metabolic level, and upregulated mRNA expression of bone formation genes in femoral bone tissue. Serum untargeted metabolomics analysis showed that 8 metabolite levels were significantly changed after ICA treatment, including increased contents of 7-dehydrocholesterol, 7-oxocholesterol, desmosterol, PC (18:1(9Z)/18:1(9Z)), PS (18:0/18:1(9Z)), N,N-dimethylaniline and 2-hydroxy-butanoic acid and decreased N2,N2-dimethylguanosine. Metabolic pathway analysis based on the above 8 metabolites indicated that ICA mainly perturbed steroid biosynthesis and glycerophospholipid metabolism. These findings suggest that ICA can effectively prevent bone loss in low-calcium diet-induced CLO by mediating steroid biosynthesis and glycerophospholipid metabolism and provide new information for the regulation of bone metabolic diseases.

scholarly journals Pulchinenosides from Pulsatilla Chinensis Increase P-Glycoprotein Activity and Induce P-Glycoprotein Expression

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yali Liu ◽  
Ling Zhang ◽  
Shaofeng Wei ◽  
Jinyang Cai ◽  
Zhenzhong Zang ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
Pcr Analysis ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Human Intestinal Epithelial Cells ◽  
Pulsatilla Chinensis ◽  
Dependent Transport ◽  
Cytotoxic Studies

Five pulchinenosides (pulchinenoside B3, pulchinenoside BD, pulchinenoside B7, pulchinenoside B10, and pulchinenoside B11) isolated from Pulsatilla chinensis (Bge) Regel saponins extract exhibited strong antitumor activities but poor gastrointestinal absorption properties. The enteric induction of P-glycoprotein (P-gp) is understood to restrict the oral bioavailability of some pharmaceutical compounds and lead to adverse drug reactions. Therefore, the present investigation was intended to delineate the impacts of pulchinenosides on cellular P-gp function and expression using Sf9 membrane vesicles and LS180 cells as a surrogate of human intestinal epithelial cells. Preliminary cytotoxic studies showed that 10 μM was an acceptable concentration for cytotoxicity and antiproliferation studies for all pulchinenosides using the alamarBlue assay. The cell cycle of LS180 cells detected by flow cytometry was not significantly influenced after 48 hours of coincubation with 10 μM of pulchinenosides. In the presence of pulchinenosides, the ATP-dependent transport of N-methyl-quinidine mediated by P-glycoprotein was stimulated significantly. The upregulation of P-glycoprotein and mRNA levels was found by Western blot and real-time PCR analysis in LS180 cells. Parallel changes indicate that all pulchinenosides are exposed to pulchinenosides-mediated transcriptional regulation. In conclusion, pulchinenosides could induce P-glycoprotein expression and directly increase its functional activity.

scholarly journals Regulation of mdr2 P-glycoprotein expression by bile salts

1997 ◽  
Vol 321 (2) ◽  
pp. 389-395 ◽  
Author(s):  
Charles M. G. FRIJTERS ◽  
Roelof OTTENHOFF ◽  
Michel J. A. van WIJLAND ◽  
Carin M. J. van NIEUWKERK ◽  
Albert K. GROEN ◽  
...  
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Control Diet ◽  
Mrna Level ◽  
Northern Blotting ◽  
Mrna Levels ◽  
Male Mice ◽  
Complete Replacement ◽  
P Glycoprotein ◽  
Mrna Content

The phosphatidyl translocating activity of the mdr2 P-glycoprotein (Pgp) in the canalicular membrane of the mouse hepatocyte is a rate-controlling step in the biliary secretion of phospholipid. Since bile salts also regulate the secretion of biliary lipids, we investigated the influence of the type of bile salt in the circulation on mdr2 Pgp expression and activity. Male mice were fed a purified diet to which either 0.1% (w/w) cholate or 0.5% (w/w) ursodeoxycholate was added. This led to a near-complete replacement of the endogenous bile salt pool (mainly tauromuricholate) by taurocholate or tauroursodeoxycholate respectively. The phospholipid secretion capacity was then determined by infusion of increasing amounts of tauroursodeoxycholate. Cholate feeding resulted in a 55% increase in maximal phospholipid secretion compared with that in mice on the control diet. Northern blotting revealed that cholate feeding increased mdr2 Pgp mRNA levels by 42%. Feeding with ursodeoxycholate did not influence the maximum rate of phospholipid output or the mdr2 mRNA content. Female mice had a higher basal mdr2 Pgp mRNA level than male mice, and this was also correlated with a higher phospholipid secretion capacity. This could be explained by the 4-fold higher basal cholate content in the bile of female compared with male mice. Our results suggest that the type of bile salts in the circulation influences the expression of the mdr2 gene.

Astragalus membranaceus modulates Th1/2 immune balance and activates PPARγ in a murine asthma model

2014 ◽  
Vol 92 (5) ◽  
pp. 397-405 ◽  
Author(s):  
Shih-Ming Chen ◽  
Yau-Sheng Tsai ◽  
Su-Wen Lee ◽  
Ya-Hui Liu ◽  
Shuen-Kuei Liao ◽  
...  
Keyword(s):  
Airway Inflammation ◽  
Chinese Herb ◽  
A549 Cells ◽  
Nuclear Hormone Receptor ◽  
Astragalus Membranaceus ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Th2 Cytokines ◽  
Asthma Model ◽  
Murine Asthma Model

Astragalus membranaceus, a traditional Chinese herb, has been used to improve airway inflammation and asthma. The present study investigated whether A. membranaceus has immunotherapeutic effects on asthma, a chronic inflammatory mucosal disease that is associated with excess production of IgE, eosinophilia, T helper 2 (Th2) cytokines, and bronchial hyperresponsiveness. An ovalbumin (OVA)-induced, chronic inflammatory airway murine asthma model was used to examine the status of pulmonary inflammation after the administration of A. membranaceus. The IgE levels in serum and bronchoalveolar lavage fluid showed a tendency to decrease after the administration of A. membranaceus. The number of eosinophils decreased and infiltration of inflammatory cells and collagen deposition declined in lung sections after A. membranaceus administration. The RNA and protein levels of Th2 cytokines and the ratio of the GATA3/T-bet mRNA levels decreased after A. membranaceus treatment. Furthermore, the mRNA level of peroxisome proliferator-activated receptor γ (PPARγ), a nuclear hormone receptor, increased in the lung tissues of A. membranaceus–treated mice. Finally, an A. membranaceus water extract activated PPARγ activity in either human embryonic kidney 293 (HEK293) or A549 cells in a PPARγ-responsive element-containing luciferase reporter assay. These results indicate that A. membranaceus has an inhibitory effect on airway inflammation in a murine model of asthma through modulating the imbalanced relationship between Th1 and Th2 cytokines.

scholarly journals Inhibition of Human Efflux Transporter ABCC2 (MRP2) by Self-emulsifying Drug Delivery System: Influences of Concentration and Combination of Excipients

2014 ◽  
Vol 17 (4) ◽  
pp. 447 ◽  
Author(s):  
Liang Li ◽  
Tao Yi ◽  
Christopher Wai-kei Lam
Keyword(s):  
Drug Delivery ◽  
Atpase Activity ◽  
Cell Model ◽  
Ultra Performance Liquid Chromatography ◽  
Inhibitory Effect ◽  
Combined Effects ◽  
Efflux Transporter ◽  
Peg 400 ◽  
Efflux Ratio ◽  
Liquid Chromatography Tandem Mass

PURPOSE: This study investigated influences of concentration and combination of excipients, commonly used in self-emulsifying drug delivery systems (SEDDS), on inhibition of human efflux transporter ABCC2 (MRP2). METHODS: Ten commonly used excipients of SEDDS with inhibitory effect on MRP2 including Cremophor® EL, Cremophor® RH, Pluronic® F127, Maisine® 35-1, β-cyclodextrin, Labrasol®, Pluronic® F68, PEG 2000, PEG 400 and Transcutol® were studied with the Caco-2 cell model. Six excipients with inhibitory effect including Cremophor® EL, Cremophor® RH, Pluronic® F127, PEG 2000, PEG 400 and Transcutol® were further analyzed using the MRP2 vesicle assay and ATPase activity assay. Ultra-performance liquid-chromatography tandem mass spectrometry was used to measure scutellarin as the MRP2 substrate. RESULTS: In studying concentration-dependent effects, five excipients including Cremophor® EL, Cremophor® RH, Pluronic® F127, Maisine® 35-1 and β-cyclodextrin showed concentration-dependent decrease in efflux ratio of scutellarin. The other five excipients did not show such phenomenon, and their inhibitory effects were restricted to be above to certain critical or minimum concentrations. In studying combined effects, PEG 2000 and Pluronic® F127 both showed combined effect with Cremophor® EL on inhibiting MRP2. However, some combinations of excipients such as PEG 400　and Transcutol® with Cremophor® EL increased the scutellarin efflux ratio and decreased the transport of scutellarin and ATPase activity, compared to Cremophor® EL alone. CONCLUSION: The above results suggest that appropriate choice of excipients according to their concentration-dependent and combined effects on MRP2 inhibition can facilitate formulation of SEDDS for improving the bioavailability of drugs that are MRP2 substrates. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Molecular Imaging in Traditional Chinese Medicine Therapy for Neurological Diseases

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Zefeng Wang ◽  
Haitong Wan ◽  
Jinhui Li ◽  
Hong Zhang ◽  
Mei Tian
Keyword(s):  
Chinese Medicine ◽  
Molecular Imaging ◽  
Traditional Chinese Medicine ◽  
Neurological Disorders ◽  
Neurological Diseases ◽  
Chinese Herb ◽  
Public Health Care ◽  
Therapeutic Effects ◽  
Cord Injury

With the speeding tendency of aging society, human neurological disorders have posed an ever increasing threat to public health care. Human neurological diseases include ischemic brain injury, Alzheimer’s disease, Parkinson’s disease, and spinal cord injury, which are induced by impairment or specific degeneration of different types of neurons in central nervous system. Currently, there are no more effective treatments against these diseases. Traditional Chinese medicine (TCM) is focused on, which can provide new strategies for the therapy in neurological disorders. TCM, including Chinese herb medicine, acupuncture, and other nonmedication therapies, has its unique therapies in treating neurological diseases. In order to improve the treatment of these disorders by optimizing strategies using TCM and evaluate the therapeutic effects, we have summarized molecular imaging, a new promising technology, to assess noninvasively disease specific in cellular and molecular levels of living models in vivo, that was applied in TCM therapy for neurological diseases. In this review, we mainly focus on applying diverse molecular imaging methodologies in different TCM therapies and monitoring neurological disease, and unveiling the mysteries of TCM.

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