Original Research Article Expressions of P-glycoprotein in treatment – Resistant Helicobacter pylori patients Marhanis Omar a, *, Andrew Crowe b , Chin Yen Tay c , Jeffery Hughes b a Faculty of Pharmacy, Universiti Kebangsaan Malaysia, 53000 Kuala Lumpur, Malaysia b School of Pharmacy, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia c School of Pathology and Laboratory Medicine, University of Western Australia, Western Australia 6009 Australia Introduction Antibiotics are used along with proton pump inhibitors to produce a synergistic effect in Helicobacter pylori eradication therapy (Stedman and Barclay, 2000). The aim of H. pylori eradication is to cure peptic ulcer disease and reduce the lifetime risk of gastric cancer (Hunt et al., 2011). In Australia, the first-line standard regimen for the H. pylori eradication is a 7 day course consisting of two antibiotics namely amoxicillin (1 g twice daily) and clarithromycin (500 mg twice daily) together with proton pump inhibitor to increase antibiotic efficacy (Stenstrőm et al., 2008). The standard eradication regimen is useful in preventing gastric ulcer and may eradicate j o u r n a l o f a p p l i e d b i o m e d i c i n e x x x ( 2 0 1 4 ) x x x – x x x a r t i c l e i n f o Article history: Received 20 September 2013 Received in revised form 28 January 2014 Accepted 4 February 2014 Available online xxx Keywords: Protein expression ABCB1 Antibiotic resistance Peptic ulcer disease Gastrointestinal tract a b s t r a c t Objective: There is an increasing incidence of Helicobacter pylori eradication therapy failure secondary to antibiotic resistance. In this study, we aimed to assess the P-glycoprotein expression levels among subjects who were H. pylori-positive and received multiple courses of eradication therapy to understand factors that may associate with their non-responses. Methods: Eleven resistant subjects were recruited during their hospital visit for upper gastrointestinal endoscopies. H. pylori infection status was confirmed by rapid urease test and bacterial culture. P-glycoprotein expressions from the antral and duodenal biopsies were measured by Western blot. The data was compared with H. pylori-negative (n = 54) and H. pylori-positive-treatment naïve (n = 22) that were recruited earlier in another study. Results: The resistant group showed higher relative antral P-glycoprotein expression com- pared to the H. pylori-negative group ( p = 0.0361). Most subjects demonstrated resistance to clarithromycin (72%), metronidazole (63.6%) or both (54.5%). No significant difference was observed between the P-glycoprotein expression in H. pylori-treatment resistant and H. pylori-positive-treatment naïve groups ( p = 0.319). Conclusion: H. pylori infection induces the expression of P-glycoprotein in the antrum. This study shows a potential protective mechanism which may be exploited through the use of P- glycoprotein inducers, such as rifabutin, may be beneficial in eradication regimens. # 2014 Faculty of Health and Social Studies, University of South Bohemia in Ceske Budejovice. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved. * Corresponding author. Tel.: +60 392897782; fax: +60 326983271. E-mail addresses: marhanis@pharmacy.ukm.my (M. Omar), A.P.Crowe@curtin.edu.au (A. Crowe), alfred.tay@uwa.edu.au (C.Y. Tay), J.D.Hughes@curtin.edu.au (J. Hughes). JAB-22; No. of Pages 7 Please cite this article in press as: Omar, M., et al., Expressions of P-glycoprotein in treatment – Resistant Helicobacter pylori patients. J. Appl. Biomed. (2014), http://dx.doi.org/10.1016/j.jab.2014.02.001 Available online at www.sciencedirect.com ScienceDirect journal homepage: http://www.elsevier.com/locate/jab 1214-021X/$ – see front matter # 2014 Faculty of Health and Social Studies, University of South Bohemia in Ceske Budejovice. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved. http://dx.doi.org/10.1016/j.jab.2014.02.001