Effect of sacubitril/valsartan on cognitive impairment in colchicine-induced Alzheimer's model in rats

Association between treatment with sacubitril/valsartan and the risk of Alzheimer's disease: a clinical update

Since 2014, sacubitril/valsartan (Entresto®) is widely prescribed for heart failure. Despite neprilysin inhibition's benefits in heart failure, concerns about potential amyloid-beta (Aβ) accumulation and Alzheimer's disease (AD) risk have persisted. This narrative review, a decade post-approval, evaluates the risk of amyloid pathology and neurocognitive disorders in long-term sacubitril/valsartan use. Clinical trials, real-world studies, and pharmacovigilance data do not indicate an increased risk of cognitive decline. In patients treated with sacubitril/valsartan blood-based amyloid biomarkers show perturbations, while neuroimaging biomarkers reveal no significant increase in amyloid load. Despite a theoretical risk of amyloid accumulation and AD under treatment with sacubitril/valsartan, current clinical data appears reassuring, and there is no signal indicating an increased risk of cognitive decline, but a perturbation of amyloid blood-based biomarkers, which implies great caution when interpreting biomarkers in this context.

Effect of spermidine on long non-coding RNAs MALAT1 in a rotenone induced-rat model of Parkinson's disease

BACKGROUND

Spermidine is a natural biologically active substance that has widespread influences on the body.

OBJECTIVE

This study aims to enhance our understanding of the potential effect of spermidine on long non-coding RNA MALAT1 and explore the underlying mechanism in the rotenone-induced rat model of Parkinson's disease.

METHODS

Rats were sacrificed after locomotor behavioral testing. Striatal tissues were used to assess the expression of MALAT1, oxidative stress markers, and autophagy markers.

RESULTS

Our study found that treatment with spermidine for 2 weeks during the induction of the model significantly improved behavioral assessment, dopamine levels, and attenuated the histopathological changes that occurred in PD in comparison to the non-treated group.

CONCLUSION

Our preliminary study supports the protective effect of spermidine on the activation of autophagy and its antioxidant properties. Part of the antioxidant activity is due to the inhibition of MALAT1. However, MALAT1 does not correlate with the spermidine-induced autophagy pathway.

Sacubitril/valsartan and the risk of incident dementia in heart failure: a nationwide propensity-matched cohort study

BACKGROUND

Sacubitril acts to inhibit neprilysin and as neprilysin is involved in amyloid-beta degradation in the central nervous system, and there is concern that sacubitril/valsartan may increase the risk of dementia. We aimed to compare the risk of incident dementia associated with sacubitril/valsartan and angiotensin II receptor blockers (ARBs).

METHODS

Patients with heart failure with reduced ejection fraction treated with either sacubitril/valsartan or ARB, identified from the Korean National Health Insurance Service database, were matched in a 1:2 ratio using propensity scores (6789 on sacubitril/valsartan and 13,578 on ARBs) and followed up for incident dementia.

RESULTS

During a mean follow-up of 2.5 years, 526 (2.6%) patients were newly diagnosed with dementia: Alzheimer dementia in 282, vascular dementia in 8, and other dementia in 236. There was no significant difference in the risk of overall dementia (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.70-1.01), Alzheimer dementia (HR 0.85, 95% CI 0.67-1.10), vascular dementia (HR 0.98, 95% CI 0.23-4.11), and all other dementias (HR 0.81, 95% CI 0.62-1.07) between sacubitril/valsartan users and ARB users. These results were consistent regardless of initial sacubitril/valsartan dose and subgroups including old age, previous mild cognitive impairment, previous stroke, and concomitant antiplatelet or anticoagulation. Sensitivity analysis with a 1-year lag period for dementia assessment confirmed the main analysis. Meanwhile, risk of incident stroke was lower in sacubitril/valsartan users compared to ARBs users.

CONCLUSIONS

In a nationwide propensity-matched cohort of patients with heart failure, sacubitril/valsartan was not associated with an increased risk of incident dementia compared to ARBs.

Pharmacological profile of agmatine: An in-depth overview

Agmatine, a naturally occurring polyamine derived from arginine via arginine decarboxylase, has been shown to play multifaceted roles in the mammalian body, impacting a wide range of physiological and pathological processes. This comprehensive review delineates the significant insights into agmatine's pharmacological profile, emphasizing its structure and metabolism, neurotransmission and regulation, and pharmacokinetics and function. Agmatine's biosynthesis is highly conserved across species, highlighting its fundamental role in cellular functions. In the brain, comparable to established neurotransmitters, agmatine acts as a neuromodulator, influencing the regulation, metabolism, and reabsorption of neurotransmitters that are key to mood disorders, learning, cognition, and the management of anxiety and depression. Beyond its neuromodulatory functions, agmatine exhibits protective effects across various cellular and systemic contexts, including neuroprotection, nephroprotection, cardioprotection, and cytoprotection, suggesting a broad therapeutic potential. The review explores agmatine's interaction with multiple receptor systems, including NMDA, α2-adrenoceptors, and imidazoline receptors, elucidating its role in enhancing cell viability, neuronal protection, and synaptic plasticity. Such interactions underpin agmatine's potential in treating neurological diseases and mood disorders, among other conditions. Furthermore, agmatine's pharmacokinetics, including its absorption, distribution, metabolism, and excretion, are discussed, underlining the complexity of its action and the potential for therapeutic application. The safety and efficacy of agmatine supplementation, demonstrated through various animal and human studies, affirm its potential as a beneficial therapeutic agent. Conclusively, the diverse physiological and therapeutic effects of agmatine, spanning neurotransmission, protection against cellular damage, and modulation of various receptor pathways, position it as a promising candidate for further research and clinical application. This review underscores the imperative for continued exploration into agmatine's mechanisms of action and its potential in pharmacology and medicine, promising advances in the treatment of numerous conditions.

Neprilysin inhibitors and risk of Alzheimer's disease: A future perspective

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disease with multifaceted neuropathological disorders. AD is characterized by intracellular accumulation of phosphorylated tau proteins and extracellular deposition of amyloid beta (Aβ). Various protease enzymes, including neprilysin (NEP), are concerned with the degradation and clearance of Aβ. Indeed, a defective neuronal clearance pathway due to the dysfunction of degradation enzymes might be a possible mechanism for the accumulation of Aβ and subsequent progression of AD neuropathology. NEP is one of the most imperative metalloproteinase enzymes involved in the clearance of Aβ. This review aimed to highlight the possible role of NEP inhibitors in AD. The combination of sacubitril and valsartan which is called angiotensin receptor blocker and NEP inhibitor (ARNI) may produce beneficial and deleterious effects on AD neuropathology. NEP inhibitors might increase the risk of AD by the inhibition of Aβ clearance, and increase brain bradykinin (BK) and natriuretic peptides (NPs), which augment the pathogenesis of AD. These verdicts come from animal model studies, though they may not be applied to humans. However, clinical studies revealed promising safety findings regarding the use of ARNI. Moreover, NEP inhibition increases various neuroprotective peptides involved in inflammation, glucose homeostasis and nerve conduction. Also, NEP inhibitors may inhibit dipeptidyl peptidase 4 (DPP4) expression, ameliorating insulin and glucagon-like peptide 1 (GLP-1) levels. These findings proposed that NEP inhibitors may have a protective effect against AD development by increasing GLP-1, neuropeptide Y (NPY) and substance P, and deleterious effects by increasing brain BK. Preclinical and clinical studies are recommended in this regard.

Anti-Hyperuricemic, Anti-Arthritic, Hemolytic Activity and Therapeutic Safety of Glycoconjugated Triazole-Phthalimides

Hyperuricemia, the metabolic alteration that leads to gout or gouty arthritis, is increasing worldwide. Glycoconjugated triazole-phthalimides show potent anti-inflammatory activity. The aim of this study was to evaluate the anti-hyperuricemia effect of glycoconjugated triazole-phthalimides. To develop hyperuricemia, groups of mice received orally potassium oxonate (250 mg/kg) for 7 days, and F2, F3 and F4 glycoconjugated triazole-phthalimides (20 mg/kg), allopurinol (300 mg/kg), and 1% carboxymethylcellulose; indomethacin (2 and 4 mg/kg) was the positive control for anti-arthritic effect. Genotoxic and mutagenic effects were evaluated by the comet and micronucleus assays, respectively. The hemolytic action of the compounds was evaluated. Phthalimides F2, F3 and F4 significantly reduced the levels of serum uric acid, creatinine and urea in hyperuricemic animals. In addition, the compounds were efficient in reducing protein denaturation in a dose-dependent manner. In an interesting way, the histopathological analysis of kidneys from groups treated with F2, F3 and F4 showed a glomerular architecture, with the Bowman's capsule and renal tubules having a normal appearance and without inflammatory changes. Also, F2 and F4 showed a small increase in micronuclei, indicating a low mutagenic effect, whilst by comet assay only, we could infer that F4 affected the frequency and damage index, thus indicating a very small genotoxic action. Similarly, the phthalimides showed a low degree of erythrocyte hemolysis (<3%). Our data demonstrate that the new glycoconjugate triazole-phthalimides have potential to treat hyperuricemia and its secondary complications, such as gouty arthritis, with a low to non-significant rate of erythrocytes hemolysis, genotoxicity and mutagenicity making these molecules strong candidates as pharmaceutical agents for treatment requiring uric-acid-lowering therapy.

Electrochemical Determination of the Drug Colchicine in Pharmaceutical and Βiological Samples Using a 3D-Printed Device

In this work, a simple, fast, and sensitive voltammetric method for the trace determination of the alkaloid drug colchicine (Colc) using a 3D-printed device is described. The electrochemical method was based on the adsorptive accumulation of the drug at a carbon-black polylactic acid (CB/PLA) working electrode, followed by voltammetric determination of the accumulated species. The plastic sensor was printed in a single step by a low-cost dual extruder 3D-printer and featured three CB/PLA electrodes (serving as working, reference, and counter electrodes) and a holder, printed from a non-conductive PLA filament. The electrochemical parameters that affected the response of the device towards Colc determination, such as accumulation time and potential, solution pH, and other variables, were optimized. Under the selected conditions, the oxidation current of Colc was proportional to the concentration of Colc, and its quantification was conducted in the concentration range of 0.6-2.2 μmol L^-1 with a limit of detection of 0.11 μmol L^-1 in phosphate buffer (pH 7.0). Both within-device and between-device reproducibility were lower than 9%, revealing satisfactory operational and fabrication reproducibility. Furthermore, the 3D-printed device was employed for the voltammetric determination of Colc in pharmaceutical tablets and in human urine with satisfactory results, justifying its suitability for low-cost routine analysis of Colc.