Molecular mechanism and functional consequences of lansoprazole-mediated heme oxygenase-1 induction

Lansoprazole protects hepatic cells against cisplatin-induced oxidative stress through the p38 MAPK/ARE/Nrf2 pathway

Lansoprazole, a proton pump inhibitor, can exert antioxidant effects through the induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, independently of the inhibition of acid secretion in the gastrointestinal tract. Lansoprazole has been reported to provide hepatoprotection in a drug-induced hepatitis animal model through the Nrf2/heme oxygenase-1 (HO1) pathway. We sought to investigate the molecular mechanism of cytoprotection by lansoprazole. An in vitro experimental model was conducted using cultured rat hepatic cells treated with lansoprazole to analyze the expression levels of Nrf2 and its downstream genes, the activity of Nrf2 using luciferase reporter assays, cisplatin-induced cytotoxicity, and signaling pathways involved in Nrf2 activation. Lansoprazole treatment of rat liver epithelial RL34 cells induced transactivation of Nrf2 and the expression of the Nrf2-dependent antioxidant genes encoding HO1, NAD(P)H quinone oxidoreductase-1, and glutathione S-transferase A2. Furthermore, cycloheximide chase experiments revealed that lansoprazole prolongs the half-life of the Nrf2 protein. Notably, cell viability was significantly increased by lansoprazole treatment in a cisplatin-induced cytotoxicity model. Moreover, the siRNA knockdown of Nrf2 fully abolished the cytoprotective effect of lansoprazole, whereas the inhibition of HO1 by tin-mesoporphyrin only partially abolished this. Finally, lansoprazole promoted the phosphorylation of p38 mitogen-activated protein kinase (MAPK) but not that of the extracellular signal-regulated kinase or the c-Jun N-terminal kinase. Using SB203580, a specific inhibitor for p38 MAPK, the lansoprazole-induced Nrf2/antioxidant response elements pathway activation and cytoprotective effects were shown to be exclusively p38 MAPK dependent. Lansoprazole was shown by these results to exert a cytoprotective effect on liver epithelial cells against the cisplatin-induced cytotoxicity through the p38 MAPK signaling pathway. This could have potential applications for the prevention and treatment of oxidative injury in the liver.

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.

Gastroesophageal Reflux and Its Association With Atrial Fibrillation: A Traditional Review

Atrial fibrillation (AF) is a common arrhythmia, and gastroesophageal reflux disease (GERD) is a common gastroenterology disease; both are highly encountered daily in clinical practice. Since both share common predisposing factors, we can conclude that there is a link between them. To date, the precise mechanism of reflux disease as a possible cause of atrial fibrillation remains uncertain. However, some possibilities can be postulated, such as the inflammation process, and sympathovagal imbalance represents the main factors for how GERD can initiate AF. Vigorous aerobic exercise in healthy people can bring about acidic esophageal reflux, which is a common risk factor for AF. Various inflammatory markers such as C-reaction protein (CRP) and interleukins have been a central role in initiating AF. A large hiatal hernia (HH) can cause direct compression on the left atrium that is possibly predisposing to atrial arrhythmogenesis. It has been sporadically reported that using a proton pump inhibitor to treat GERD in patients with coexisting AF has a noticeable effect on decreasing symptoms of AF and recurrence with less cost and side effects.

Computational discovery of therapeutic candidates for preventing preterm birth

Few therapeutic methods exist for preventing preterm birth (PTB), or delivery before completing 37 weeks of gestation. In the US, progesterone (P4) supplementation is the only FDA-approved drug for use in preventing recurrent spontaneous PTB. However, P4 has limited effectiveness, working in only approximately one-third of cases. Computational drug repositioning leverages data on existing drugs to discover novel therapeutic uses. We used a rank-based pattern-matching strategy to compare the differential gene expression signature for PTB to differential gene expression drug profiles in the Connectivity Map database and assigned a reversal score to each PTB-drug pair. Eighty-three drugs, including P4, had significantly reversed differential gene expression compared with that found for PTB. Many of these compounds have been evaluated in the context of pregnancy, with 13 belonging to pregnancy category A or B - indicating no known risk in human pregnancy. We focused our validation efforts on lansoprazole, a proton-pump inhibitor, which has a strong reversal score and a good safety profile. We tested lansoprazole in an animal inflammation model using LPS, which showed a significant increase in fetal viability compared with LPS treatment alone. These promising results demonstrate the effectiveness of the computational drug repositioning pipeline to identify compounds that could be effective in preventing PTB.

Proton Pump Inhibitor Use Before ICU Admission Is Not Associated With Mortality of Critically Ill Patients

Some studies have shown that the long-term use of proton pump inhibitors (PPIs) is associated with many adverse events that may increase mortality; however, the relationship between premorbid PPI use and in-hospital mortality has yet to be validated in critically ill patients. Therefore, we performed this study to determine whether the preadmission use of PPIs is associated with mortality in patients admitted to the intensive care unit. This was a retrospective study with a large and freely accessible database in critical-care medicine (the Multiparameter Intelligent Monitoring in Intensive Care III project). The clinical data and outcomes of 17 473 patients, consisting of 1895 in the PPI group, 514 in the H₂ -receptor antagonist group, and 15 064 control subjects, were collected during their hospital stay. The study outcome was in-hospital mortality. A total of 17 473 patients were included in our study. PPI use was associated with significantly increased in-hospital mortality in the original model without adjustment for any parameters (odds ratio 1.19; 95%CI 1.03-1.38; P = .02). However, after adjustments had been made for age, sex, Elixhauser score, Simplified Acute Physiology Score, laboratory results, vasopressor use, ventilator use, and other parameters, PPIs were not associated with significantly increased in-hospital mortality (odds ratio 1.04; 95%CI 0.87-1.26; P = .614). In the subgroup analysis among patients with renal or liver disease, we still found that PPIs were not associated with a significant increase in in-hospital mortality. We found no association between PPI use before ICU admission and increased in-hospital mortality in critically ill patients compared with control subjects.

Association of atrial fibrillation and gastroesophageal reflux disease: Natural and therapeutic linkage of the two common diseases

Atrial fibrillation (AF) is a common arrhythmia and gastroesophageal reflux disease (GERD) is popular in Japan. The two common diseases share several predisposing factors such as lifestyle and senescence, and inflammation and oxidative stress play an important role in their development and progression. Incidental cases of AF treated successfully by proton pump inhibitor (PPI) applied for coexisting GERD have been sporadically reported. An increasing evidence indicates that GERD induces the initiation and the perpetuation of AF. This is caused by the autonomic nerve influence, mechanical compression, and propagation of local inflammation due to proximity of left atrium (LA) and lower esophagus. Meanwhile, AF also develops GERD by mechanical and inflammatory actions of LA characterized by remodeling and inflammation. The robust association of AF with GERD is not limited to their natural interaction, i.e., pharmacological or nonpharmacological treatment of AF is reported to aggravate GERD. Many cardiac drugs (anticoagulants, calcium antagonists, and nitrates) induce esophageal mucosal damage and lower esophageal sphincter relaxation promoting acid reflux. These drugs are frequently prescribed in patients with AF for stroke prevention, rate control, and for coexisting coronary heart disease. Catheter ablation also yields both GERD and esophageal thermal injury, which is a precursor lesion of atrioesophageal fistula. The notion that AF and GERD are mutually interdependent is widely and empirically recognized. However, mechanistic link of the two common diseases and objective evaluation of PPI as an adjunctive AF treatment warrant future large-scale prospective trials.

Proton pump inhibitor use is not associated with cardiac arrhythmia in critically ill patients

Hypomagnesemia can lead to cardiac arrythmias. Recently, observational data have linked chronic proton pump inhibitor (PPI) exposure to hypomagnesemia. Whether PPI exposure increases the risk for arrhythmias has not been well studied. Using a large, single-center inception cohort of critically ill patients, we examined whether PPI exposure was associated with admission electrocardiogram readings of a cardiac arrhythmia in more than 8000 patients. There were 25.4% PPI users, whereas 6% were taking a histamine 2 antagonist. In all, 14.0% had a cardiac arrhythmia. PPI use was associated with an unadjusted risk of arrhythmia of 1.15 (95% CI,1.00-1.32; P =.04) and an adjusted risk of arrhythmia of 0.91 (95% CI, 0.77-1.06; P =.22). Among diuretic users (n = 2476), PPI use was similarly not associated with an increased risk of cardiac arrhythmia. In summary, in a large cohort of critically ill patients, PPI exposure is not associated with an increased risk of cardiac arrhythmia.

Proton pump inhibitors as also inhibitors of atrial fibrillation

Proton pump inhibitors (PPIs) are widely used for the treatment of acid-related upper digestive diseases, including gastric and duodenal ulcer and gastroesophageal reflux disease (GERD). Remarkably, several small clinical trials have shown that these drugs also reduce the symptoms and frequency of atrial fibrillation (AF) episodes in patients treated for comorbid acid reflux. Although the mechanism remains unclear, the effect might pinpoint a connection between GERD and AF. To this end, it is known that both oxidants and inflammation affect initiation and maintenance of AF, and PPIs may reduce symptoms and frequency of AF episodes through their antioxidant and anti-inflammatory effects. This review focuses on the anti-AF effects of PPIs beyond their inhibition of gastric acid production.

The proton-pump inhibitor lansoprazole enhances amyloid beta production

A key event in the pathogenesis of Alzheimer’s disease (AD) is the accumulation of amyloid-β (Aβ) species in the brain, derived from the sequential cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. Based on a systems biology study to repurpose drugs for AD, we explore the effect of lansoprazole, and other proton-pump inhibitors (PPIs), on Aβ production in AD cellular and animal models. We found that lansoprazole enhances Aβ37, Aβ40 and Aβ42 production and lowers Aβ38 levels on amyloid cell models. Interestingly, acute lansoprazole treatment in wild type and AD transgenic mice promoted higher Aβ40 levels in brain, indicating that lansoprazole may also exacerbate Aβ production in vivo. Overall, our data presents for the first time that PPIs can affect amyloid metabolism, both in vitro and in vivo.

Heme oxygenase-1 system and gastrointestinal inflammation: A short review

Heme oxygenase-1 (HO-1) system catalyzes heme to biologically active products: carbon monoxide, biliverdin/bilirubin and free iron. It is involved in maintaining cellular homeostasis and many physiological and pathophysiological processes. A growing body of evidence indicates that HO-1 activation may play an important protective role in acute and chronic inflammation of gastrointestinal tract. This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal inflammation studied to date. The ability to upregulate HO-1 by pharmacological means or using gene therapy may offer therapeutic strategies for gastrointestinal inflammation in the future.

Heme oxygenase-1: a novel therapeutic target for gastrointestinal diseases

Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the catabolism of heme, followed by production of biliverdin, free iron and carbon monoxide (CO). HO-1 is a stress-responsive protein induced by various oxidative agents. Recent studies demonstrate that the expression of HO-1 in response to different inflammatory mediators may contribute to the resolution of inflammation and has protective effects in several organs against oxidative injury. Although the mechanism underlying the anti-inflammatory actions of HO-1 remains poorly defined, both CO and biliverdin/bilirubin have been implicated in this response. In the gastrointestinal tract, HO-1 is shown to be transcriptionally induced in response to oxidative stress, preconditioning and acute inflammation. Recent studies suggest that the induction of HO-1 expression plays a critical protective role in intestinal damage models induced by ischemia-reperfusion, indomethacin, lipopolysaccharide-associated sepsis, trinitrobenzene sulfonic acid, and dextran sulfate sodium, indicating that activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in the gastrointestinal tract. In addition, CO derived from HO-1 is shown to be involved in the regulation in gastro-intestinal motility. These in vitro and in vivo data suggest that HO-1 may be a novel therapeutic target in patients with gastrointestinal diseases.

Heme oxygenase-1 system and gastrointestinal tumors

Heme oxygenase-1 (HO-1) system catabolizes heme into three products: carbon monoxide, biliverdin/bilirubin and free iron. It is involved in many physiological and pathophysiological processes. A great deal of data has demonstrated the roles of HO-1 in the formation, growth and metastasis of tumors. The interest in this system by investigators involved in gastrointestinal tumors is fairly recent, and few papers on HO-1 have touched upon this subject. This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal tumors studied to date. The implications for possible therapeutic manipulation of HO-1 in gastrointestinal tumors are also discussed.