Omeprazole induces vascular remodeling by mechanisms involving xanthine oxidoreductase and matrix metalloproteinase activation

Inhibitors of gastric acid secretion increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling

The use of inhibitors of gastric acid secretion (IGAS), especially proton pump inhibitors (PPI), has been associated with increased cardiovascular risk. While the mechanisms involved are not known, there is evidence supporting increased oxidative stress, a major activator of matrix metalloproteinases (MMP), as an important player in such effect. However, there is no study showing whether other IGAS such as histamine H2-receptor blockers (H2RB) cause similar effects. This study aimed at examining whether treatment with the H2RB ranitidine promotes oxidative stress resulting in vascular MMP activation and corresponding functional and structural alterations in the vasculature, as compared with those found with the PPI omeprazole. Male Wistar rats were treated (4 weeks) with vehicle (2% tween 20), omeprazole (10 mg/Kg/day; i.p.) or ranitidine (100 mg/Kg/day; gavage). Then the aorta was collected to perform functional, biochemical, and morphometric analysis. Both ranitidine and omeprazole increased gastric pH and oxidative stress assessed in situ with the fluorescent dye dihydroethidium (DHE) and with lucigenin chemiluminescence assay. Both IGAS augmented vascular activated MMP-2. These findings were associated with aortic remodeling (increased media/lumen ratio and number of cells/μm2). Both IGAS also impaired the endothelium-dependent relaxation induced by acetylcholine (isolated aortic ring preparation). This study provides evidence that the H2RB ranitidine induces vascular dysfunction, redox alterations, and remodeling similar to those found with the PPI omeprazole. These findings strongly suggest that IGAS increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling, which helps to explain the increased cardiovascular risk associated with the use of those drugs.

Quercetin decreases cardiac hypertrophic mediators and maladaptive coronary arterial remodeling in renovascular hypertensive rats without improving cardiac function

Oxidative stress and MMP activity are found in the hearts and arteries in hypertension and contribute to the resulting hypertrophy and dysfunction. Quercetin is a flavonoid that reduces MMP-2 activity and ameliorates hypertrophic vascular remodeling of hypertension. The hypothesis is that treatment of hypertensive rats with quercetin ameliorates coronary maladaptive remodeling and decreases hypertrophic cardiac dysfunction by decreasing oxidative stress and MMP activity. Male Sprague-Dawley two-kidney, one-clip (2K1C) and Sham rats were treated with quercetin (10 mg/kg/day) or its vehicle for 8 weeks by gavage. Rats were analyzed at 10 weeks of hypertension. Systolic blood pressure (SBP) was examined by tail-cuff plethysmography. Cardiac left ventricles were used to determine MMP activity by in situ zymography and oxidative stress by dihydroethidium. Immunofluorescence was performed to detect transforming growth factor (TGF)-β and nuclear factor kappa B (NFkB). Morphological analyses of heart and coronary arteries were done by H&E and picrosirius red, and cardiac function was measured by Langendorff. SBP was increased in 2K1C rats, and quercetin did not reduce it. However, quercetin decreased both oxidative stress and TGF-β in the left ventricles of 2K1C rats. Quercetin also decreased the accentuated MMP activity in left ventricles and coronary arteries of 2K1C rats. Quercetin ameliorated hypertension-induced coronary arterial hypertrophic remodeling, although it did not reduce cardiac hypertrophic remodeling and dysfunction. Quercetin decreases cardiac oxidative stress and TGF-β and MMP activity in addition to improving coronary remodeling, yet does not ameliorate cardiac dysfunction in 2K1C rats.

Untargeted metabolomics analysis of omeprazole-enhanced chemosensitivity to cisplatin in mice with non-small cell lung cancer

Drug resistance of tumors remains a major barrier in cisplatin (CDDP)-based chemotherapy. Omeprazole (OME) is often utilized during chemotherapy to alleviate gastrointestinal symptoms. In a previous investigation, we demonstrated a protective effect of OME against CDDP-induced kidney injury. To further establish whether OME could enhance chemosensitivity to CDDP and the underlying mechanisms, an in vivo tumor-bearing mouse model with CDDP-resistant A549 non-small cell lung cancer (A549/CDDP) was established in the current study. A high-performance liquid chromatography-time of flight mass spectrometry (HPLC-TOF/MS)-based untargeted metabolomics approach for tumor tissue and serum was employed to explore the mechanisms underlying the enhanced therapeutic effects of co-administration of CDDP and OME. Notably, tumor weights of mice in the CDDP + OME group were significantly decreased compared with those treated with CDDP alone. HE and TUNEL staining revealed more significant apoptosis of tumor cells in the group co-administered CDDP + OME relative to CDDP alone. Overexpression of multidrug resistance-associated protein 2 in CDDP-resistant tumors was significantly reversed upon treatment with CDDP + OME. PCA score plots of the groups co-treated with CDDP + OME were clearly separated from those treated with CDDP alone in metabolomics analysis for tumor and serum samples, clearly suggesting that co-administration of OME enhances the antitumor effect of CDDP. Subsequently, 10 and 7 metabolites in CDDP + OME group with significant changes in tumor and serum compared with CDDP group, respectively, were identified. Pathway analysis both in tumor and serum samples revealed regulation of the metabolism of purines, several amino acids and riboflavin in enhanced chemotherapy with both OME and CDDP. The collective findings provide beneficial novel insights into drug-drug interactions, which could improve the application of CDDP in clinical practice.