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efflux pump inhibition

Indu Jaiswal, Amita Jain, Sanjeev Kumar Verma, Pooja Singh, Surya Kant, Mastan Singh
BACKGROUND: Mycobacterium can develop drug resistance (DR) by mutation of its existing gene. However, the existence of DR without mutation shows the need to look for an alternative mechanism such as the role of efflux pumps. In this study, we examined the effect of efflux pump inhibitors on isoniazid (INH) susceptibility in clinical isolates of Mycobacterium tuberculosis (Mtb). MATERIALS AND METHODS: Resazurin microtiter assay was used to examine the effect of efflux pump inhibitors on minimum inhibitory concentration (MIC) levels of INH in eighteen Mtb clinical isolates...
November 2017: Lung India: Official Organ of Indian Chest Society
Pu Shi, Mingxiang Liao, Bei-Ching Chuang, Robert Griffin, Judy Shi, Marc Hyer, John K Fallon, Philip C Smith, Chao Li, Cindy Q Xia
1. Red blood cell (RBC) partitioning is important in determining pharmacokinetic and pharmacodynamic properties of a compound; however, active transport across RBC membranes is not well understood, particularly without transporter-related cell membrane proteomics data. 2. In this study, we quantified breast cancer resistance protein (BCRP/Bcrp) and MDR1/P-glycoprotein (P-gp) protein expression in RBCs from humans, monkeys, dogs, rats, and mice using nanoLC/MS/MS, and evaluated their effect on RBC partitioning and plasma exposure of their substrates...
November 3, 2017: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
Farhad Jeddi, Narges Soozangar, Mohammad Reza Sadeghi, Mohammad Hossein Somi, Masoud Shirmohamadi, Amir-Taher Eftekhar-Sadat, Nasser Samadi
The efficacy of chemotherapeutic agents remains very poor in gastric cancer (GC) patients due to the development of multidrug resistance (MDR) phenotype. The nuclear factor erythroid 2-related factor 2 (Nrf2), is a pivotal transcriptional factor that regulates phase II detoxifying enzymes, antioxidants and efflux transporters including P-glycoprotein (P-gp). The aim of this study was to investigate the association of Nrf2 and P-gp and their correlations with clinicopathological criteria in GC patients.Nrf2 and MDR1/P-gp expressions in both mRNA and protein levels were examined by real-time PCR and immunohistochemical staining (IHC) respectively, in endoscopic biopsy samples from60 GC patients compared with those expressions in non-GC individuals...
October 26, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Seyed Abbas Mirzaei, Neda Gholamian Dehkordi, Mahsa Ghamghami, Amir Hossein Amiri, Elaheh Dalir Abdolahinia, Fatemeh Elahian
Furanocoumarins derived from herbal and citrus extracts can act as antibacterial, antioxidant, immunomodulator, apoptotic, and selective anticancer agents, prompting a biological investigation to determine and predict their clinical therapeutic significance. Here, the cell cytotoxic effects of bergapten and xanthotoxin were analyzed alone and in combination with standard chemotherapeutics on three multidrug resistant cells and their nonresistant parental counterparts. The furanocoumarins modulatory effects on MDR1, BCRP, and MRP pump expression and function were investigated...
October 25, 2017: Toxicology and Applied Pharmacology
C Li, H-G Xue, L-J Feng, M-L Wang, P Wang, X-D Gai
OBJECTIVE: Multidrug resistance (MDR) is a major cause of chemotherapy failure in the treatment of cancer patients. This study aimed to determine whether saikosaponin D (SSd) can enhance the efficacy of the anticancer drug doxorubicin (Dox) both in vitro and in vivo and whether SSd can alter Dox pharmacokinetics in the serum of mice. MATERIALS AND METHODS: MCF-7/adr cells were used to investigate the effect of SSd on reversing MDR. Cell viability was assessed by MTT assay...
October 2017: European Review for Medical and Pharmacological Sciences
Si-Min Zhou, Lan-Lan Dong, Yuan He, Hong Xiao
OBJECTIVE: To construct a genetically engineered Escherichia coli expressing chromate (Cr) ion transporter ChrA and test its Cr resistance capacity. METHODS: ChrA gene was cloned by PCR from the DNA template of Serratia sp. S2 and linked with the prokaryotic vector pET-28a (+). The recombinant vector was transformed into E.coli BL21 (DE3) cells for expression of ChrA protein. Cr (VI) risistance and Cr (VI) uptake and efflux of the engineered bacteria were tested, and the effects of Cr loading time, oxyanions (ulfate, molybdate, vanadate, tungstate), and respiratory inhibitors (valinomycin, CN(-), oligomycin, and NADH) on Cr (VI) efflux were examined to analyze the pathway of Cr (VI) transport by ChrA protein...
October 20, 2017: Nan Fang Yi Ke da Xue Xue Bao, Journal of Southern Medical University
Borisz Varga, Ákos Csonka, Andrea Csonka, Joseph Molnár, Leonard Amaral, Gabriella Spengler
Phenothiazines have been used in many areas of medicine, mainly in psychopharmacology. These compounds are able to effectively inhibit dopamine, histamine, serotonin, acetylcholine, and α-adrenergic receptors; thus, their effect and side-effect profiles are extremely diverse. Besides their antipsychotic activity, phenothiazines have a significant antimicrobial effect as well, since they can enhance the bactericidal function of macrophages and inhibit efflux pumps. They are also able to eliminate bacterial resistance plasmids and destroy bacteria by their membrane-destabilizing effect...
November 2017: Anticancer Research
Samsher Singh, Nitin P Kalia, Prashant Joshi, Ajay Kumar, Parduman R Sharma, Ashok Kumar, Sandip B Bharate, Inshad A Khan
This study elucidated the role of boeravinone B, a NorA multidrug efflux pump inhibitor, in biofilm inhibition. The effects of boeravinone B plus ciprofloxacin, a NorA substrate, were evaluated in NorA-overexpressing, wild-type, and knocked-out Staphylococcus aureus (SA-1199B, SA-1199, and SA-K1758, respectively). The mechanism of action was confirmed using the ethidium bromide accumulation and efflux assay. The role of boeravinone B as a human P-glycoprotein (P-gp) inhibitor was examined in the LS-180 (colon cancer) cell line...
2017: Frontiers in Microbiology
Jian Xu, Rokeya Tasneen, Charles A Peloquin, Deepak V Almeida, Si-Yang Li, Kala Barnes-Boyle, Yu Lu, Eric Nuermberger
Drug efflux pumps play an important role in intrinsic and acquired drug resistance. Verapamil, an efflux inhibitor that enhances the activity of bedaquiline, clofazimine and other drugs against Mycobacterium tuberculosis has been proposed as a potential adjunctive agent for treatment of tuberculosis (TB). However, the extent to which verapamil enhances in vivo efficacy by inhibiting bacterial efflux pumps versus inhibiting mammalian drug transporters to improve oral bioavailability has not been delineated. We found that verapamil potentiated the in vitro activity of bedaquiline and clofazimine against M...
October 16, 2017: Antimicrobial Agents and Chemotherapy
Rania M Hathout, Sherweit H El-Ahmady, AbdelKader A Metwally
The current study introduces a new idea of utilising several bio/chemoinformatics tools in comparing two bio-similar natural molecules viz. curcumin and bisdemethoxycurcumin (BDMC) in order to select a potential nose-to-brain remedy for Alzheimer disease. The comparison comprised several bio/chemo informatics tools. It encompassed all levels starting from loading the drug in a certain carrier; PLGA nanoparticles, to the biopharmaceutical level investigating the interaction with mucin and inhibition of P-gp blood-brain barrier efflux pumps...
October 12, 2017: Natural Product Research
Rolando Cannalire, Diana Machado, Tommaso Felicetti, Sofia Santos Costa, Serena Massari, Giuseppe Manfroni, Maria Letizia Barreca, Oriana Tabarrini, Isabel Couto, Miguel Viveiros, Stefano Sabatini, Violetta Cecchetti
Mycobacterium avium is a difficult-to-treat pathogen able to quickly develop drug resistance. Like for other microbial species, overexpression of efflux pumps is one of the main mechanisms in developing multidrug resistance. Although the use of efflux pumps inhibitors (EPIs) represents a promising strategy to reverse resistance, to date few M. avium EPIs are known. Recently, we showed that in-house 2-phenylquinoline S. aureus NorA EPIs exhibited also a good activity against M. avium efflux pumps. Herein, we report a series of 3-phenylquinolones designed by modifying the isoflavone biochanin A, a natural EPI of the related M...
September 12, 2017: European Journal of Medicinal Chemistry
Iva Jancíková, Jakub Zahumenský, Yvetta Gbelská, Dana Gášková
Multidrug transporters are often responsible for failure of medical treatment, since they expel a variety of structurally and functionally unrelated drugs out of the cell. We found that the fluorescent probe diS-C3(3) is a substrate of not only Pdr5p of Saccharomyces cerevisiae (ScPdr5p) but also of its less-explored Kluyveromyces lactis homologue (KlPdr5p). This enabled us to compare the ability of azoles to competitively inhibit the Pdr5p-mediated probe efflux in the two species. In K. lactis, these azoles completely inhibit probe transport by KlPdr5p and also compete with each other for transport...
November 1, 2017: FEMS Yeast Research
Jannik Donner, Michael Reck, Boyke Bunk, Michael Jarek, Constantin Benjamin App, Jan P Meier-Kolthoff, Jörg Overmann, Rolf Müller, Andreas Kirschning, Irene Wagner-Döbler
The myxobacterial secondary metabolite carolacton inhibits growth of Streptococcus pneumoniae and kills biofilm cells of the caries- and endocarditis-associated pathogen Streptococcus mutans at nanomolar concentrations. Here, we studied the response to carolacton of an Escherichia coli strain that lacked the outer membrane protein TolC. Whole-genome sequencing of the laboratory E. coli strain TolC revealed the integration of an insertion element, IS5, at the tolC locus and a close phylogenetic relationship to the ancient E...
September 2017: MSphere
Namrata Rana, Helen E Jesse, Mariana Tinajero-Trejo, Jonathan A Butler, John D Tarlit, Milena L von Und Zur Muhlen, Christoph Nagel, Ulrich Schatzschneider, Robert K Poole
Carbon monoxide-releasing molecules (CORMs) are a promising class of new antimicrobials, with multiple modes of action that are distinct from those of standard antibiotics. The relentless increase in antimicrobial resistance, exacerbated by a lack of new antibiotics, necessitates a better understanding of how such novel agents act and might be used synergistically with established antibiotics. This work aimed to understand the mechanism(s) underlying synergy between a manganese-based photoactivated carbon monoxide-releasing molecule (PhotoCORM), [Mn(CO)3(tpa-κ(3)N)]Br [tpa=tris(2-pyridylmethyl)amine], and various classes of antibiotics in their activities towards Escherichia coli EC958, a multi-drug-resistant uropathogen...
September 28, 2017: Microbiology
Xuchun Liu, Gengyun Sun
Shikonin (SHK) is a natural naphthoquinone pigment isolated from Lithospermum erythrorhizon, that has been reported to suppress the growth of a number of cancer cell types. Adriamycin (AD) is typically used as an effective anticancer agent; however, it has the propensity to induce drug resistance. The aim of the present study was to investigate the effects of SHK alone and in combination with AD on lung adenocarcinoma cells and the underlying molecular mechanisms of their effects. Colony formation, MTT and propidium iodide staining assays demonstrated that the co-treatment of A549 cells with SHK and AD significantly decreased cell viability and potently induced apoptosis...
October 2017: Oncology Letters
Mengjiao Lu, Cuixiang Yu, Xueyan Cui, Jinyi Shi, Lei Yuan, Shujuan Sun
Candida species are the primary opportunistic pathogens of nosocomial fungal infections, causing both superficial and life-threatening systemic infections. Combination therapy for fungal infections has attracted considerable attention, especially for those caused by drug-resistant fungi. Gentamicin, an aminoglycoside antibiotic, has a weak antifungal activity against Fusarium. The aim of this study was to investigate the interactions of gentamicin with azoles against the Candida species and the underlying mechanism...
September 21, 2017: International Journal of Antimicrobial Agents
Jonathan Nzakizwanayo, Paola Scavone, Shirin Jamshidi, Joseph A Hawthorne, Harriet Pelling, Cinzia Dedi, Jonathan P Salvage, Charlotte K Hind, Fergus M Guppy, Lara M Barnes, Bhavik A Patel, Khondaker M Rahman, Mark J Sutton, Brian V Jones
Proteus mirabilis forms extensive crystalline biofilms on indwelling urethral catheters that block urine flow and lead to serious clinical complications. The Bcr/CflA efflux system has previously been identified as important for development of P. mirabilis crystalline biofilms, highlighting the potential for efflux pump inhibitors (EPIs) to control catheter blockage. Here we evaluate the potential for drugs already used in human medicine (fluoxetine and thioridazine) to act as EPIs in P. mirabilis, and control crystalline biofilm formation...
September 22, 2017: Scientific Reports
Siwen Li, Hongzhuo Shi, Wenqiang Chang, Yi Li, Ming Zhang, Yanan Qiao, Hongxiang Lou
We isolated twelve sesquiterpenes from Chinese liverwort Tritomaria quinquedentata (Huds.) Buch., including four new compounds. Among them, five eudesmane sesquiterpenes were ineffective against Candida albicans wild strain SC5314 but active towards efflux pumps-deficient strain DSY654 using Alamar blue assay. Further test of the most active agent of ent-isoalantolactone (8, ent-iLL) showed that it also inhibited the yeast-to-hyphal switch of DSY654 cells. The intracellular content measurement using high performance liquid chromatography (HPLC) revealed that ent-iLL was intracellularly accumulated in C...
September 9, 2017: Bioorganic & Medicinal Chemistry
A Şükrü Aynacıoğlu, Ayhan Bilir, Kenji Kadomatsu
Multidrug resistance (MDR) to chemotherapy may significantly affect the outcome of cancer treatment. ATP-dependent drug efflux pumps, including P-glycoprotein (P-gp), contribute to the resistance of various chemotherapeutic agents. Overexpression of P-gp in tumor cells induces chemoresistance via pumping the anticancer drugs out of the cells. In addition to taking part in many biological processes such as development, reproduction and repair, midkine (MK) also plays important roles in the pathogenesis of malignant diseases as well as in the regulation of MDR...
September 2017: Medical Hypotheses
Divya Muthiah, Richard Callaghan
ZSTK474 is a potent phosphoinositide 3-kinase (PI3K) inhibitor that reduces cell proliferation via G1-arrest. However, there is little information on the susceptibility of this anticancer drug to resistance conferred by the multidrug pumps P-glycoprotein (ABCB1) and ABCG2. We have demonstrated that ZSTK474 generated cytotoxicity in cells over-expressing either pump with potency similar to that in drug sensitive cells. In addition, the co-administration of ZSTK474 with the cytotoxic anti-cancer drugs vinblastine and mitoxantrone caused a potentiated cytotoxic effect in both drug sensitive and efflux pump expressing cells...
November 15, 2017: European Journal of Pharmacology
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