scholarly journals Antioxidant, Anti-Inflammatory, and Multidrug Resistance Modulation Activity of Silychristin Derivatives

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 303 ◽  
Author(s):  
Jitka Viktorová ◽  
Simona Dobiasová ◽  
Kateřina Řehořová ◽  
David Biedermann ◽  
Kristýna Káňová ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Resistance Modulation

Silychristin A is the second most abundant compound of silymarin. Silymarin complex was previously described as an antioxidant with multidrug resistance modulation activity. Here, the results of a classical biochemical antioxidant assay (ORAC) were compared with a cellular assay evaluating the antioxidant capacity of pure silychristin A and its derivatives (anhydrosilychristin, isosilychristin and 2,3-dehydrosilychristin A). All the tested compounds acted as antioxidants within the cells, but 2,3-dehydro- and anhydro derivatives were almost twice as potent as the other tested compounds. Similar results were obtained in LPS-stimulated macrophages, where 2,3-dehydro- and anhydrosilychristin inhibited NO production nearly twice as efficiently as silychristin A. The inhibition of P-glycoprotein (P-gp) was determined in vitro, and the respective sensitization of doxorubicin-resistant ovarian carcinoma overproducing P-gp was detected. Despite the fact that the inhibition of P-gp was demonstrated in a concentration-dependent manner for each tested compound, the sensitization of the resistant cell line was observed predominantly for silychristin A and 2,3-dehydrosilychristin A. However, anhydrosilychristin and isosilychristin affected the expression of both the P-gp (ABCB1) and ABCG2 genes. This is the first report showing that silychristin A and its 2,3-dehydro-derivative modulate multidrug resistance by the direct inhibition of P-gp, in contrast to anhydrosilychristin and isosilychristin modulating multidrug resistance by downregulating the expression of the dominant transmembrane efflux pumps.

Dietary Nucleotide Supplements in Infant Formula Modify the Expression of P-glycoprotein in the Intestinal Epithelium in vitro

2009 ◽  
Vol 79 (56) ◽  
pp. 381-387 ◽  
Author(s):  
Mary Bebawy ◽  
Christine Rasmussen ◽  
Shwetha Sambasivam ◽  
Shisan Bao
Keyword(s):  
Infant Formula ◽  
Dependent Manner ◽  
Drug Bioavailability ◽  
Concentration Dependent Manner ◽  
Glycoprotein P ◽  
Colon Cells ◽  
P Glycoprotein ◽  
Dietary Nucleotides

The effect of dietary nucleotides at concentrations found in supplemented infant formula on P-glycoprotein (P-gp) expression in colon cells was examined. We report that P-gp expression in colon cells was significantly decreased in a time- and concentration-dependent manner. When colon cells were co-cultured with lymphocytes, so as to mimic the involvement of gut-associated lymphoid tissue in normal gut pathophysiology, we observed a reversal of this effect with a demonstrated increase in P-gp expression. These findings have important implications on effects of nucleotide exposure on increasing drug bioavailability, reducing the capacity for xenobiotic efflux, and increasing the risk of inflammatory bowel disease in susceptible infants. Future studies are directed at defining both the mechanisms underlying these findings and effects of dietary nucleotide supplementation in vivo.

scholarly journals Immuno-oncology agent IPI-549 is a modulator of P-glycoprotein (P-gp, MDR1, ABCB1)-mediated multidrug resistance (MDR) in cancer: In vitro and in vivo

2019 ◽  
Vol 442 ◽  
pp. 91-103 ◽  
Author(s):  
Albert A. De Vera ◽  
Pranav Gupta ◽  
Zining Lei ◽  
Dan Liao ◽  
Silpa Narayanan ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Glycoprotein P ◽  
P Glycoprotein

scholarly journals ATP-dependent thermostabilization of human P-glycoprotein (ABCB1) is blocked by modulators

2019 ◽  
Vol 476 (24) ◽  
pp. 3737-3750 ◽  
Author(s):  
Sabrina Lusvarghi ◽  
Suresh V. Ambudkar
Keyword(s):  
Conformational Changes ◽  
Drug Transport ◽  
Atp Hydrolysis ◽  
Atp Binding ◽  
Dependent Manner ◽  
Deficient Mutant ◽  
Concentration Dependent Manner ◽  
Glycoprotein P ◽  
Binding Domains ◽  
P Glycoprotein

P-glycoprotein (P-gp), an ATP-binding cassette transporter associated with multidrug resistance in cancer cells, is capable of effluxing a number of xenobiotics as well as anticancer drugs. The transport of molecules through the transmembrane (TM) region of P-gp involves orchestrated conformational changes between inward-open and inward-closed forms, the details of which are still being worked out. Here, we assessed how the binding of transport substrates or modulators in the TM region and the binding of ATP to the nucleotide-binding domains (NBDs) affect the thermostability of P-gp in a membrane environment. P-gp stability after exposure at high temperatures (37–80°C) was assessed by measuring ATPase activity and loss of monomeric P-gp. Our results show that P-gp is significantly thermostabilized (>22°C higher IT50) by the binding of ATP under non-hydrolyzing conditions (in the absence of Mg2+). By using an ATP-binding-deficient mutant (Y401A) and a hydrolysis-deficient mutant (E556Q/E1201Q), we show that thermostabilization of P-gp requires binding of ATP to both NBDs and their dimerization. Additionally, we found that transport substrates do not affect the thermal stability of P-gp either in the absence or presence of ATP; in contrast, inhibitors of P-gp including tariquidar and zosuquidar prevent ATP-dependent thermostabilization in a concentration-dependent manner, by stabilizing the inward-open conformation. Altogether, our data suggest that modulators, which bind in the TM regions, inhibit ATP hydrolysis and drug transport by preventing the ATP-dependent dimerization of the NBDs of P-gp.

scholarly journals Pharmacokinetic Alteration of Paclitaxel by Ferulic Acid Derivative

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 593 ◽  
Author(s):  
Jaeok Lee ◽  
Song Wha Chae ◽  
LianJi Ma ◽  
So Yeon Lim ◽  
Sarah Alnajjar ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Ferulic Acid ◽  
Acid Derivative ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Substrate Drug

P-glycoprotein (P-gp) is known to be involved in multidrug resistance (MDR) and modulation of pharmacokinetic (PK) profiles of substrate drugs. Here, we studied the effects of synthesized ferulic acid (FA) derivatives on P-gp function in vitro and examined PK alteration of paclitaxel (PTX), a well-known P-gp substrate drug by the derivative. Compound 5c, the FA derivative chosen as a significant P-gp inhibitor among eight FA candidates by in vitro results, increased PTX AUCinf as much as twofold versus the control by reducing PTX elimination in rats. These results suggest that FA derivative can increase PTX bioavailability by inhibiting P-gp existing in eliminating organs.

scholarly journals Reversal of Cancer Multidrug Resistance (MDR) Mediated by ATP-Binding Cassette Transporter G2 (ABCG2) by AZ-628, a RAF Kinase Inhibitor

2020 ◽  
Vol 8 ◽  
Author(s):  
Jing-Quan Wang ◽  
Qiu-Xu Teng ◽  
Zi-Ning Lei ◽  
Ning Ji ◽  
Qingbin Cui ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Kinase Inhibitor ◽  
Efflux Pump ◽  
Simulation Analysis ◽  
Chemotherapeutic Agents ◽  
Dynamics Simulation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Raf Kinase

Overexpression of ABCG2 remains a major impediment to successful cancer treatment, because ABCG2 functions as an efflux pump of chemotherapeutic agents and causes clinical multidrug resistance (MDR). Therefore, it is important to uncover effective modulators to circumvent ABCG2-mediated MDR in cancers. In this study, we reported that AZ-628, a RAF kinase inhibitor, effectively antagonizes ABCG2-mediated MDR in vitro. Our results showed that AZ-628 completely reversed ABCG2-mediated MDR at a non-toxic concentration (3 μM) without affecting ABCB1-, ABCC1-, or ABCC10 mediated MDR. Further studies revealed that the reversal mechanism was by attenuating ABCG2-mediated efflux and increasing intracellular accumulation of ABCG2 substrate drugs. Moreover, AZ-628 stimulated ABCG2-associated ATPase activity in a concentration-dependent manner. Docking and molecular dynamics simulation analysis showed that AZ-628 binds to the same site as ABCG2 substrate drugs with higher score. Taken together, our studies indicate that AZ-628 could be used in combination chemotherapy against ABCG2-mediated MDR in cancers.

Activation of Nitric Oxide Release and Oxidative Metabolism by Leukotrienes B4, C4, and D4 in Human Polymorphonuclear Leukocytes

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1399-1405 ◽  
Author(s):  
Gerd Lärfars ◽  
Frédérique Lantoine ◽  
Marie-Aude Devynck ◽  
Jan Palmblad ◽  
Hans Gyllenhammar
Keyword(s):  
Nitric Oxide ◽  
Rank Order ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Kinetic Properties ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cysteinyl Leukotrienes ◽  
Mediators Of Inflammation

Abstract Because arachidonate metabolites are potent mediators of inflammation, we have studied the effects of leukotriene B4(LTB4) and the cysteinyl leukotrienes C4 and D4 (LTC4 and LTD4) on the release of nitric oxide (NO), in vitro, by human polymorphonuclear granulocytes (PMN). Two independent and highly sensitive real-time methods were used for these studies, ie, the NO-dependent oxidation of oxyhemoglobin (HbO2) to methemoglobin and a NO-sensitive microelectrode. When activated with LTB4, LTC4, or LTD4, but not with other lipoxygenase products such as 5S-HETE, 5-oxo-ETE or 5S,12S-diHETE, PMN produced NO in a stimulus- and concentration-dependent manner. The rank order of potency was LTB4 = LTC4 > LTD4, corresponding to 232 ± 50 pmol of NO/106 PMN for 100 nmol/L LTB4 after 30 minutes. The kinetic properties of the responses were similar for all three leukotrienes with a maximum response at 13 ± 3 minutes. Cysteinyl leukotriene and LTB4 antagonists inhibited the agonist-induced NO production by 70%, and treatment with Bordetella pertussis toxin, or chelation of cytosolic Ca2+, [Ca2+]i, also efficiently inhibited this response. In contrast, treatment of PMN with cytochalasin B (5 μg/mL) enhanced the LTB4-induced NO formation by 86%. Thus, this is the first demonstration that the cysteinyl leukotrienes LTC4 and LTD4, as well as LTB4, activate NO release from human PMN by surface receptor, G-protein and [Ca2+]i-dependent mechanisms. This effect differs from activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, for which only LTB4is an activator.

Detection of P-glycoprotein in ovarian cancer: a molecular marker associated with multidrug resistance.

1985 ◽  
Vol 3 (3) ◽  
pp. 311-315 ◽  
Author(s):  
D R Bell ◽  
J H Gerlach ◽  
N Kartner ◽  
R N Buick ◽  
V Ling
Keyword(s):  
Ovarian Cancer ◽  
Multidrug Resistance ◽  
Resistance Mutation ◽  
Advanced Ovarian Cancer ◽  
Surface Glycoprotein ◽  
Glycoprotein P ◽  
Cell Surface Glycoprotein ◽  
P Glycoprotein ◽  
Mutant Lines

A multidrug resistance phenotype is frequently observed in animal and human cell lines selected for in vitro resistance to a single chemotherapeutic agent. Overexpression of a highly conserved cell-surface glycoprotein (P-glycoprotein) is consistently associated with this phenotype in these mutant lines. A monoclonal antibody against P-glycoprotein was used to examine tumor samples from five patients with advanced ovarian cancer for evidence of P-glycoprotein overexpression. High levels of P-glycoprotein were detected in samples from two patients suggesting that a multidrug resistance mutation may also occur in ovarian cancer. This finding has broad implications for the understanding of nonresponse to chemotherapy in a variety of human neoplasms, and may provide a rational explanation for failure of chemotherapy in treatment of advanced ovarian cancer.

P-glycoprotein in human sarcoma: evidence for multidrug resistance.

1987 ◽  
Vol 5 (9) ◽  
pp. 1452-1460 ◽  
Author(s):  
J H Gerlach ◽  
D R Bell ◽  
C Karakousis ◽  
H K Slocum ◽  
N Kartner ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Multidrug Resistant ◽  
Surface Glycoprotein ◽  
Glycoprotein P ◽  
Cell Surface Glycoprotein ◽  
P Glycoprotein ◽  
Drug Treatments ◽  
Tumor Types ◽  
Human Sarcoma

Overexpression of an immunologically conserved, cell-surface glycoprotein (P-glycoprotein) is consistently associated with multidrug resistance in cell lines in vitro. A preliminary survey of specimens from 12 solid tumor types in our laboratories indicates significant overexpression of P-glycoprotein in some sarcomas. When tested by immunoblotting with monoclonal antibodies directed against P-glycoprotein; tumors from six of 25 sarcoma patients displayed elevated levels of P-glycoprotein. Three of the sarcoma patients exhibiting P-glycoprotein had not previously been exposed to chemotherapy, implying that overexpression of this marker and possible concomitant multidrug resistance may not depend only on selection during prior drug treatments. The P-glycoprotein overexpression in the sarcoma specimens is evidence for the presence of multidrug resistant cells in these tumors; thus, our data suggest that this mode of resistance may have clinical significance in sarcoma patients.

scholarly journals Multidrug Resistance Modulation Activity of Silybin Derivatives and Their Anti-Inflammatory Potential

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 455 ◽  
Author(s):  
Simona Dobiasová ◽  
Kateřina Řehořová ◽  
Denisa Kučerová ◽  
David Biedermann ◽  
Kristýna Káňová ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Biological Activities ◽  
Biologically Active ◽  
Cancer Drug ◽  
Optical Isomers ◽  
Dependent Manner ◽  
Cancer Resistance ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Dose Dependent

Silybin is considered to be the main biologically active component of silymarin. Its oxidized derivative 2,3-dehydrosilybin typically occurs in silymarin in small, but non-negligible amounts (up to 3%). Here, we investigated in detail complex biological activities of silybin and 2,3-dehydrosilybin optical isomers. Antioxidant activities of pure stereomers A and B of silybin and 2,3-dehydrosilybin, as well as their racemic mixtures, were investigated by using oxygen radical absorption capacity (ORAC) and cellular antioxidant activity (CAA) assay. All substances efficiently reduced nitric oxide production and cytokines (TNF-α, IL-6) release in a dose-dependent manner. Multidrug resistance (MDR) modulating potential was evaluated as inhibition of P-glycoprotein (P-gp) ATPase activity and regulation of ATP-binding cassette (ABC) protein expression. All the tested compounds showed strong dose-dependent inhibition of P-gp pump. Moreover, 2,3-dehydrosilybin A (30 µM) displayed the strongest sensitization of doxorubicin-resistant ovarian carcinoma. Despite these significant effects, silybin B was the only compound acting directly upon P-gp in vitro and also downregulating the expression of respective MDR genes. This compound altered the expression of P-glycoprotein (P-gp, ABCB1), multidrug resistance-associated protein 1 (MRP1, ABCC1) and breast cancer resistance protein (BCRP, ABCG2). 2,3-Dehydrosilybin AB exhibited the most effective inhibition of acetylcholinesterase activity. We can clearly postulate that silybin derivatives could serve well as modulators of a cancer drug-resistant phenotype.

scholarly journals Effects of steroids and verapamil on P-glycoprotein ATPase activity: progesterone, desoxycorticosterone, corticosterone and verapamil are mutually non-exclusive modulators

1996 ◽  
Vol 317 (2) ◽  
pp. 515-522 ◽  
Author(s):  
Stéphane ORLOWSKI ◽  
Lluis M. MIR ◽  
Jean BELEHRADEK ◽  
Manuel GARRIGOS
Keyword(s):  
Atpase Activity ◽  
Binding Sites ◽  
Drug Transport ◽  
Competitive Inhibition ◽  
Membrane Vesicles ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Synergistic Modulation

P-glycoprotein (P-gp) is a membranous ATPase responsible for the multidrug resistance (MDR) phenotype. Using membrane vesicles prepared from the highly resistant cell line DC-3F/ADX we studied the influence on P-gp ATPase activity of four progesterone derivatives which specifically bind to P-gp and reverse MDR. Progesterone and desoxycorticosterone stimulate P-gp ATPase activity with, respectively, apparent concentrations giving half-maximal activation of 20–25 μM and 40–50 μM, and activation factors of 2.3 (at 100 μM progesterone) and 1.8 (at 170 μM desoxycorticosterone). Hydrocortisone above 100 μM stimulates P-gp ATPase activity while corticosterone has no apparent stimulating effect. Our data are consistent with the location of the binding sites for the progesterone derivatives on the P-gp membranous domain. The effects of these steroids on verapamil-stimulated P-gp ATPase activity support a non-competitive mechanism, i.e. the binding sites for verapamil and steroids are mutually non-exclusive for P-gp ATPase modulation. A similar non-competitive inhibition of progesterone-stimulated P-gp ATPase activity by desoxycorticosterone or by corticosterone leads to the conclusion that these steroids, although sharing related structures, have distinct modulating sites on P-gp. As expected from their mutually non-exclusive interactions on P-gp, progesterone and verapamil when mixed induce a synergistic modulation of P-gp ATPase activity. Since drug transport by P-gp is believed to be coupled to its ATPase activity, a corresponding synergistic effect of these two modulators for the inhibition of P-gp-mediated drug resistance can be expected.

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