Novel Peritoneal Sclerosis Rat Model Developed by Administration of Bleomycin and Lansoprazole.

In our preliminary experiment, peritoneal sclerosis likely induced by peritoneal dialysis was unexpectedly observed in the livers of rats given bleomycin and lansoprazole. We examined whether this peritoneal thickening around the liver was time-dependently induced by administration of both drugs. Male Wistar rats were injected with bleomycin and/or lansoprazole for 2 or 4 weeks. The 3YB-1 cell line derived from rat fibroblasts was treated by bleomycin and/or lansoprazole for 24 h. The administration of both drugs together, but not individually, thickened the peritoneal tissue around the liver. There was accumulation of collagen fibers, macrophages, and eosinophils under mesothelial cells. Expressions of Col1a1, Mcp1 and Mcp3 genes were increased in the peritoneal tissue around the liver and in 3YB-1 cells by the administration of both drugs together, and Opn genes had increased expressions in this tissue and 3YB-1 cells. Mesothelial cells indicated immunoreactivity against both cytokeratin, a mesothelial cell marker, and αSMA, a fibroblast marker, around the livers of rats given both drugs. Administration of both drugs induced the migration of macrophages and eosinophils and induced fibrosis associated with the possible activation of fibroblasts and the possible promotion of the mesothelial-mesenchymal transition. This might become a novel model of peritoneal sclerosis for peritoneal dialysis.

Lansoprazole-induced osteoporosis via the IP3R- and SOCE-mediated calcium signaling pathways.

BACKGROUND: Many clinical studies have shown a correlation between proton pump inhibitors (PPIs) and osteoporosis or fractures. The purpose of this study was to establish a murine model of chronic oral PPI administration to verify whether PPIs caused bone metabolic impairment and investigate the relevant molecular mechanism underlying the effects of PPIs on MC3T3-E1 murine osteoblasts. METHODS: A lansoprazole-induced bone loss model was used to investigate the damaging effects of PPIs. In vivo, immunohistochemistry, Hematoxylin-Eosin (HE) staining, micro-CT analysis, and blood biochemical analyses were used to evaluate the effect of lansoprazole on bone injury in mice. In vitro, the effects of lansoprazole and related signaling pathways in MC3T3-E1 cells were investigated by CCK-8 assays, EdU assays, flow cytometry, laser confocal microscopy, patch clamping, reverse transcription-quantitative polymerase chain reaction and Western blotting. RESULTS: After 6 months of lansoprazole gavage in ICR mice, the micro-CT results showed that compared with that in the vehicle group, the bone mineral density (BMD) in the high-dose group was significantly decreased (P < 0.05), and the bone microarchitecture gradually degraded. Biochemical analysis of bone serum showed that blood calcium and phosphorus were both decreased (P < 0.01). We found that long-term administration of lansoprazole impaired skeletal function in mice. In vitro, we found that lansoprazole (LPZ) could cause calcium overload in MC3T3-E1 cells leading to apoptosis, and 2-APB, an inhibitor of IP3R calcium release channel and SOCE pathway, effectively blocked increase in calcium caused by LPZ, thus protecting cell viability. CONCLUSIONS: Longterm administration of LPZ induced osteoporotic symptoms in mice, and LPZ triggered calcium increases in osteoblasts in a concentration-dependent manner. Intracellular calcium ([Ca2+]i) persisted at a high concentration, thereby causing endoplasmic reticulum stress (ERS) and inducing osteoblast apoptosis.

Lansoprazole a Proton Pump Inhibitor Prevents IBD by Reduction of Oxidative Stress and NO Levels in the Rat.

The inflammatory disease's increased prevalence leads to a major concern around the world. Still, there is a lack of effective and successful therapy in the reversal of Inflammatory Bowel Disease (IBD) symptoms. Whereas, reactive oxygen species (ROS) production and muddled defense capacity of antioxidants in IBD subjects reported several times. Many proton pump inhibitors have been reported previously for their anti-inflammatory effect. The present study is aimed to assess the ameliorative effect of lansoprazole in experimentally induced IBD in rats. Thirty-six female Sprague Dawley rats were divided equally into six groups based on their body weight. Lansoprazole (1, 5, and 10 mg/kg, p.o.) and 5-aminosalicylate (5-ASA, 100 mg/kg, p.o.) served as standard control respectively, given for 18 days once a day. On the 11th day of the study, colitis was induced by intrarectal instillation of 2, 4-Dinitrobenzene sulfonic acid (DNBS), and treatment was continued for the next 7 days. Administration of lansoprazole (at 5 and 10 mg/kg) significantly reduced DAI (Disease Activation Index) and CMDI (Colon Macroscopic Damage Index); which further justifies a reduction in colon inflammation grades, as well as histopathological changes, and reflected by the stalling of body weight. The anti-inflammatory effects were indicated by lowered MPO (myeloperoxidase) and SOD (superoxide dismutase) in colon tissue as well as restores colonic NO (nitric oxide) level. The study shows lansoprazole improved DAI and CMDI scores, reduction of neutrophil infiltration, and an improved antioxidant status indicating an anti-ulcerative effect in DNBS-induced experimental colitis that is comparable with 5-ASA treatment.

Regulation of adipocyte differentiation and metabolism by lansoprazole.

AIMS: Lansoprazole (LPZ) is one of the most commonly prescribed drugs for treatment of acid-related diseases, and it is increasingly recognized for its potential application as an anti-diabetic therapy. Although LPZ target tissues remain poorly understood, possible sites of action include adipose tissue. In this study, we assessed effects of LPZ on adipocyte differentiation and function by using 3T3-L1 preadipocytes and HFD-induced obesity mice as an in vitro and in vivo model, respectively. MAIN METHODS: Oil red O staining and intracellular triacylglycerol content were used to determine lipid accumulation. Glucose uptake was performed to measure mature adipocyte function. Expression of adipocyte genes was determined by qRT-PCR and immunoblotting. KEY FINDINGS: LPZ has dual effects on differentiation of 3T3-L1 cells. At low concentrations, LPZ enhanced adipocyte differentiation via induction of PPARγ and C/EBPα, two master adipogenic transcription factors, as well as lipogenic proteins, ACC1 and FASN. Increasing of adipocyte number subsequently increased basal and insulin-stimulated glucose uptake, and expression of Glut4 mRNA. Conversely, high concentrations of LPZ strongly inhibited differentiation and expression of PPARγ and C/EBPα, and maintained expression of preadipocytes markers, ß-catenin and Pref-1. Inhibition of adipogenesis by LPZ reduced mature adipocyte number, Glut4 mRNA expression and insulin-stimulated glucose uptake. In addition, treatment with LPZ at 200 mg/kg significantly reduced body weight gain and total fat mass in HFD-induced obese mice. SIGNIFICANCE: These results indicate that effects of LPZ on adipocyte differentiation are dependent on concentration and are correlated with PPARγ and C/EBPα.

Predictive Performance of Physiologically Based Pharmacokinetic (PBPK) Modeling of Drugs Extensively Metabolized by Major Cytochrome P450s in Children.

The accuracy of physiologically based pharmacokinetic (PBPK) model prediction in children, especially those younger than 2 years old, has not been systematically evaluated. The aim of this study was to characterize the pediatric predictive performance of the PBPK approach for 10 drugs extensively metabolized by CYP1A2 (theophylline), CYP2C8 (desloratidine, montelukast), CYP2C9 (diclofenac), CYP2C19 (esomeprazole, lansoprazole), CYP2D6 (tramadol), and CYP3A4 (itraconazole, ondansetron, sufentanil). Model performance in children was evaluated by comparing simulated plasma concentration-time profiles with observed clinical results for each drug and age group. PBPK models reasonably predicted the pharmacokinetics of desloratadine, diclofenac, itraconazole, lansoprazole, montelukast, ondansetron, sufentanil, theophylline, and tramadol across all age groups. Collectively, 58 out of 67 predictions were within 2-fold and 43 out of 67 predictions within 1.5-fold of observed values. Developed PBPK models can reasonably predict exposure in children age 1 month and older for an array of predominantly CYP metabolized drugs.

Lansoprazole is an antituberculous prodrug targeting cytochrome bc1.

Better antibiotics capable of killing multi-drug-resistant Mycobacterium tuberculosis are urgently needed. Despite extensive drug discovery efforts, only a few promising candidates are on the horizon and alternative screening protocols are required. Here, by testing a panel of FDA-approved drugs in a host cell-based assay, we show that the blockbuster drug lansoprazole (Prevacid), a gastric proton-pump inhibitor, has intracellular activity against M. tuberculosis. Ex vivo pharmacokinetics and target identification studies reveal that lansoprazole kills M. tuberculosis by targeting its cytochrome bc1 complex through intracellular sulfoxide reduction to lansoprazole sulfide. This novel class of cytochrome bc1 inhibitors is highly active against drug-resistant clinical isolates and spares the human H(+)K(+)-ATPase thus providing excellent opportunities for targeting the major pathogen M. tuberculosis. Our finding provides proof of concept for hit expansion by metabolic activation, a powerful tool for antibiotic screens.

Membrane anchor of cytochrome P450 reductase suppresses the uncoupling of cytochrome P450.

Cytochrome P450 reductase (CPR) is an important redox partner of microsomal CYPs. CPR is composed of a membrane anchor and a catalytic domain that contains FAD and flavin mononucleotide (FMN) as redox centers and mediates electron transfer to CYP. Although the CPR membrane anchor is believed to be requisite for interaction with CYP, its physiological role is still controversial. To clarify the role of the anchor, we constructed a mutant (Δ60-CPR) in which the N-terminal membrane anchor was truncated, and studied its effect on binding properties, electron transfer to CYP2C19, and drug metabolism. We found that Δ60-CPR could bind to and transfer electrons to CYP2C19 as efficiently as WT-CPR, even in the absence of lipid membrane. In accordance with this, Δ60-CPR could mediate metabolism of amitriptyline (AMT) and imipramine (IMP) in the absence of lipids, although activity was diminished. However, Δ60-CPR failed to metabolize omeprazole (OPZ) and lansoprazole (LPZ). To clarify the reason for this discrepancy in drug metabolism, we investigated the uncoupling reaction of the CYP catalytic cycle. By measuring the amount of H2O2 by-product, we found that shunt pathways were markedly activated in the presence of OPZ/LPZ in the Δ60-CPR mutant. Because H2O2 levels varied among the drugs, we conclude that the proton network in the distal pocket of CYP2C19 is perturbed differently by different drugs, and activated oxygen is degraded to become H2O2. Therefore, we propose a novel role for the membrane anchor as a suppressor of the uncoupling reaction in drug metabolism by CYP.

Prediction of inter-individual variability in the pharmacokinetics of CYP2C19 substrates in humans.

Significant inter-individual variability of exposure for CYP2C19 substrates may be only partly due to genetic polymorphism. Therefore, the in vivo inter-individual variability in hepatic intrinsic clearance (CL(int,h)) of CYP2C19 substrates was estimated from reported AUC values using Monte Carlo simulations. The coefficient of variation (CV) for CL(int,h) in poor metabolizers (PM) expected from genotypes CYP2C19*2/*2, CYP2C19*3/*3 or CYP2C19*2/*3 was estimated as 25.8% from the CV for AUC of omeprazole in PMs. With this, CVs of CL(int,h) in extensive metabolizers (EM: CYP2C19*1/*1), intermediate metabolizers (IM: CYP2C19*1/*2 or *3) and ultra-rapid metabolizers (UM), CYP2C19*17/*17 and *1/*17, were estimated as 66.0%, 55.8%, 6.8% and 48.0%, respectively. To validate these CVs, variability in the AUC of CYP2C19 substrates lansoprazole and rabeprazole, partially metabolized by CYP3A4 in EMs and IMs, were simulated using the CV in CL(int,h) for CYP2C19 EMs and IMs and 33% of the CV previously reported for CYP3A4. Published values were within 2.5-97.5 percentile range of simulated CVs for the AUC. Furthermore, simulated CVs for the AUC of omeprazole and lansoprazole in ungenotyped populations were comparable with published values. Thus, estimated CL(int,h) variability can predict variability in the AUC of drugs metabolized not only by CYP2C19 but also by multiple enzymes.

The stereoselectivity of CYP2C19 on R- and S-isomers of proton pump inhibitors.

PPIs are mainly metabolized by CYP2C19. It has a stereoselectivity effect on R- and S-isomers of PPIs according to previous studies. However, no study has been reported to elucidate the binding mechanism at the atomic level based on the CYP2C19 crystal structure. Recently, the advent of the first crystal structure of CYP2C19 allowed us to take in silico approaches including MD simulation, MM/GBSA calculation, energy decomposition, and alanine scanning to explore the stereoselectivity of CYP2C19 on R- and S-isomers of PPIs. The key residues responsible for the selective binding for R- and S-isomers of omeprazole, lansoprazole, and pantoprazole are disclosed by free energy and alanine scanning analysis. Structural analysis showed that chiral isomers of PPIs alter their conformations to have strong binding affinities with CYP2C19. Furthermore, a theoretical pharmacophore model of PPIs was obtained with the importance of pharmacophore feature being weighted, basing on our results. Our results are valuable for designing and synthesizing new generation of PPIs in the future.