Antacid Therapy in Coronary Artery Disease and Heart Failure: Proton Pump Inhibitors vs. H2 Receptor Blockers

Radioprotective Effects of Vitamin C, Cimetidine, and Famotidine on Lipid Peroxidase and Hepatic Glutathione Levels in Mouse Liver

Radiation therapy is one of the most effective treatments for approximately 60% of patients with cancer. During radiation exposure, the overproduction of reactive oxygen species (ROS) disrupts the lipid layer of the membrane, leading to subsequent peroxide radical formation. Cimetidine (Cim) and famotidine (Fam) are histamine H2 receptor antagonists (H2 blocker), also known as peptic ulcer drugs, that exert radioprotective effects. Vitamin C (Vit.C) is an effective free radical and ROS scavenger with significant radioprotective effects. In this experimental study, male mice (6-8 weeks and 28 ± 3 g) were used in five groups. To evaluate ionizing radiation, gamma rays were used at two doses of 2 and 4 Gy and different doses of Cim, Fam, and Vit.C administered as the protectives. Finally, the livers of the mice were isolated and homogenized. The levels of lipid peroxidase and reduced and oxidized glutathione were measured using standard methods. With increasing radiation dose, lipid peroxidase activity, GSSG level, and glutathione content increased. The findings showed that in the drug-only group, Vit.C had better protection than the other two drugs, and the combination of the three drugs had excellent radiation protection. Radiation protection of normal cells in radiotherapy is a valuable necessity. A number of drugs can protect cells against ionizing radiation through different mechanisms. The results suggest that Fam, Cim, and Vit.C can be radioprotective individually or in combination.

Gastroprotection in Heart Failure and Outcomes: A Systematic Review of Proton Pump Inhibitors and Histamine-2 Receptor Antagonists

PURPOSE

The management of heart failure (HF) frequently includes gastroprotection via proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs). This systematic review evaluates their impact on HF outcomes, including exacerbation, hospitalization, mortality, and major adverse cardiac events (MACE).

METHODS

In accordance with PRISMA guidelines, a complete search across databases such as PubMed/Medline, Scopus, and Web of Science was conducted until December 10, 2023. The inclusion criteria covered research on adult patients with HF that focused on the effects of PPI and H2RA usage. The risk of bias was determined via the Newcastle-Ottawa Scale (NOS), and data were synthesized quantitatively.

RESULTS

Eleven studies encompassing 996,498 participants were analyzed. The data is not consistent across all research; however, some have suggested that PPI use may be linked to an increased risk of cardiovascular illnesses and heart failure aggravation. Conversely, H2RAs appeared to offer potential benefits in certain high-risk groups, potentially reducing all-cause and cardiovascular mortality. However, the limitations of the available studies should be taken into consideration when interpreting these findings.

CONCLUSION

The review suggests that there may be differences in the impact of PPIs and H2RAs on HF outcomes. While some evidence indicates that PPIs may be linked to increased risks in HF patients, and H2RAs may offer potential benefits, these findings are not definitive and should be interpreted with caution. Further research is necessary to clarify these associations and guide clinical practice.

REGISTRATION

PROSPERO CRD42023491752.

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.

Recent Advances in Metal-Hydride-Based Disease Treatment

In comparison to traditional antioxidant treatment methods, the use of hydrogen to eliminate reactive oxygen species from the body has the advantages of high biological safety, strong selectivity, and high clearance rate. As an energy storage material, metal hydrides have been extensively studied and used in transporting hydrogen as clean energy, which can achieve a high hydrogen load and controlled hydrogen release. Considering the antioxidant properties of hydrogen and the delivery ability of metal hydrides, metal-hydride-based disease treatment strategies have attracted widespread attention. Up to now, metal hydrides have been reported for the treatment of tumors and a range of inflammation-related diseases. However, limited by the insufficient investment, the use of metal hydrides in disease treatment still has many shortcomings, such as low targeting efficiency, limited therapeutic activity, and complex material preparation process. Particularly, metal hydrides have been found to have a series of optical, acoustic, and catalytic properties when scaled up to the nanoscale, and these properties are also widely used to promote disease treatment effects. From this new perspective, we comprehensively summarize the very recent research progress on metal-hydride-based disease treatment in this review. Ultimately, the challenges and prospects of such a burgeoning cancer theranostics modality are outlooked to provide inspiration for the further development and clinical translation of metal hydrides.

Inappropriate Use of Proton Pump Inhibitors Increases Cardiovascular Events in Patients with Coronary Heart Disease

Antiplatelet drugs, as the cornerstone of the treatment of coronary heart disease, control the progression of the disease, but bring a higher risk of gastrointestinal bleeding. Relevant guidelines recommend the use of proton pump inhibitors (PPIs) to minimize the risk of gastrointestinal bleeding in patients receiving dual antiplatelet therapy. But for people at low risk of gastrointestinal bleeding, the harms associated with routine use of PPIs may far outweigh the benefits. PPIs increase the risk of lower gastrointestinal bleeding, inhibit the effect of antiplatelet drugs, impair vascular endothelial function, meanwhile induce hypomagnesemia, iron deficiency, vitamins D and K deficiency, etc. Eventually, PPIs may lead to an increase in cardiovascular events. However, the situation is that PPIs are often overused. This review elucidates the mechanisms by which PPIs increase cardiovascular events, thereby reminding clinicians to rationally prescribe PPIs.