Systemic Actions of SGLT2 Inhibition on Chronic mTOR Activation as a Shared Pathogenic Mechanism between Alzheimer's Disease and Diabetes

Exploring novel therapeutic strategies: Could psychedelic perspectives offer promising solutions for Alzheimer's disease comorbidities?

The increasing prevalence of dementia within an ageing global population, combined with prolonged life expectancy, accentuates Alzheimer's disease (AD) as a multifaceted healthcare challenge. This challenge is further compounded by the limited therapeutic options currently available. Addressing the intricacies of AD management, the mitigation of comorbidities has emerged as a pivotal facet of treatment. Comorbid conditions, such as neurobehavioral symptoms, play a role in shaping the clinical course, management, and outcomes of this pathology; highlighting the importance of comprehensive care approaches for affected individuals. Exploration of psychedelic compounds in psychiatric and palliative care settings has recently uncovered promising therapeutic potential, enhancing neuroplasticity, emotional processing and connection. These effects are particularly relevant in the context of AD, where psychedelic therapy offers hope not only for mitigating core symptoms but also for addressing the array of comorbidities associated with this condition. The integration of this comprehensive method offers a chance to significantly enhance the care provided to those navigating the intricate landscape of AD. Therefore, the current paper reviews the intricate link between more frequent additional health conditions that may coexist with dementia, particularly in the context of AD, and explores the therapeutic potential of psychedelic compounds in addressing these concurrent conditions.

Neuroprotective effects of empagliflozin against scopolamine-induced memory impairment and oxidative stress in rats

Alzheimer's disease (AD) is one of the most common age-related neurodegenerative disorders. The main medicinal theory for the management of AD belongs to the acetyl-cholinesterase-inhibition pathway and NMDA antagonism. Recent investigation proposed memory improvement by sodium-glucose co-transporter 2 (SGLT2) inhibitors which indicated to improve glycemic control in adults with type 2 diabetes mellitus. According to the lack of sufficient evidence about the efficacy of empagliflozin (EMPA) for memory improvement, in comparison with donepezil (DON), the present research was carried out in order to investigate this hypothesis towards scopolamine-induced neurotoxicity on experimental male Wistar rats. The animals divided into two sets, each included 4 groups: The first set of Healthy animals [Control, EMPA (4 or 10 mg/kg), DON (1 mg/kg)]. The second set of rat Alzheimer model, which received 2 mg/kg Scopolamine by intraperitoneal route for 10 days followed by other treatments [AD, AD+ EMPA (4 or 10 mg/kg) and AD+DON]. Normal rats and AD rats, with each group receiving different substances for 8 consecutive days and 24 h after the accomplishment of the drug administrations, the memory functions assessed through Morris water maze (MWM) paradigm. This task was followed by decapitation of rats in order to evaluate the biochemical oxidative stress parameters in brain tissue. Our data indicated that EMPA significantly improved animals' performance in the behavioral test with a significant decrease in oxidative stress and antioxidant imbalance. In addition, EMPA (4 mg/kg) significantly reduced both cellular malondialdehyde and protein carbonyl content while conversely increased the total reduced glutathione content. Besides, the levels of total as well as endogenous antioxidants in the ferric reducing antioxidant power assay reported to be augmented. It seems that EMPA significantly improved both cellular biochemical aspects and memory performance in animal models in accordance with histopathological assessments. Conclusively, 4 mg/kg EMPA demonstrated better results in all aspects that were evaluated during this research.

Resveratrol: A Natural Compound Targeting the PI3K/Akt/mTOR Pathway in Neurological Diseases

Neurological diseases (NDs), including neurodegenerative disorders and acute injuries, are a significant global health concern. The PI3K/Akt/mTOR pathway, a crucial signaling cascade, is responsible for the survival of cells, proliferation, and metabolism. Dysregulation of this pathway has been linked to neurological conditions, indicating its potential as a vital target for therapeutic approaches. Resveratrol (RSV), a natural compound found in berries, peanuts, and red grapes, has antioxidant, anti-cancer, and anti-inflammatory effects. Its ability to modulate the PI3K/Akt/mTOR pathway has been interesting in NDs. Studies have shown that RSV can activate the PI3K/Akt pathway, promoting cell survival and inhibiting apoptosis of neuronal cells. Its impact on mTOR, a downstream effector of Akt, further contributes to its neuroprotective effects. RSV's ability to restore autophagic flux presents a promising avenue for therapeutic intervention. Its anti-inflammatory properties suppress inflammatory responses by inhibiting key signaling molecules within the pathway. Additionally, RSV's role in enhancing mitochondrial function contributes to its neuroprotective profile. This study highlights RSV's potential as a multifaceted therapeutic agent in NDs, specifically by PI3K/Akt/mTOR pathway modulation. Additional investigation is required to optimize its therapeutic capacity in diverse neurological conditions.

Reducing Alzheimer's disease risk with SGLT2 inhibitors: From glycemic control to neuroprotection

Recent research has established a strong link between metabolic abnormalities and an increased risk of dementia. In parallel, there is growing epidemiological evidence supporting the neuroprotective effects of antidiabetic medications against cognitive impairments. Among these, sodium-glucose co-transporter (SGLT2) inhibitors have emerged as pharmacological candidates with promising potential in alleviating the burden of age-related diseases, particularly neurodegenerative diseases (NDD). SGLT2 inhibitor therapies are FDA-approved medications routinely prescribed to manage diabetes. This novel class was initially developed to address cardiovascular disorders and to reduce the risk of hypoglycemia associated with insulin-secretagogue agents. It subsequently attracted growing interest for its beneficial effects on central nervous system (CNS) disorders. However, the molecular mechanisms through which these glucose-lowering therapies mitigate cognitive decline and limit the progression of certain brain degenerative diseases remain largely unexplored. Consequently, the neuroscientific community needs further studies that gather, analyze, and critically discuss the available mechanistic evidence regarding the neuroprotective effects of SGLT2 inhibitors. This review aims to critically examine the most relevant published findings, both in vitro and in vivo, as well as human studies evaluating the impact of SGLT2 inhibitors exposure on Alzheimer's disease (AD). It seeks to integrate the current understanding of their beneficial effects at the molecular level and their role in addressing the pathophysiology and neuropathology of AD. These insights will help extend our knowledge of how SGLT2 inhibitor therapies are associated with reduced risk of dementia and thus shed light on the link between diabetes and AD.

Empagliflozin Dampens Doxorubicin-Induced Chemobrain in Rats: The Possible Involvement of Oxidative Stress and PI3K/Akt/mTOR/NF-κB/TNF-α Signaling Pathways

Chemobrain is a cognitive impairment observed in up to 75% of cancer patients treated with doxorubicin (DOX). Cognitive deficits associated with DOX are complex, and multiple interplay pathways contribute to memory impairment and the loss of concentration. Empagliflozin (EMPA), a sodium-glucose co-transporter-2 (SGLT-2) inhibitor with neuroprotective potential, has recently been elucidated because of its regulatory effects on oxidative stress and neuroinflammation. Thus, this study aimed to explore the protective mechanisms of EMPA in DOX-induced chemobrain. Rats were allocated to four groups: normal (NC), EMPA, DOX, and EMPA + DOX. Chemobrain was induced in the third and fourth groups by DOX (2 mg/kg, IP) on the 0th, 7th, 14th, and 21st days of the study, while EMPA was administered (10 mg/kg, PO) for 28 consecutive days in both the EMPA and EMPA + DOX groups. Behavioral and biochemical assessments were then performed. Rats treated with DOX exhibited significant memory, learning, and muscle coordination dysfunctions. Moreover, DOX boosted oxidative stress in the brain, as evidenced by elevated malondialdehyde (MDA) content together with decreased levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and reduced glutathione (GSH). Neuroinflammation was also observed as an upsurge of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) (p65). Additionally, DOX diminished the expression of brain-derived neurotrophic factor (BDNF) and increased phosphoinositol-3-kinase (PI3K), phosphorylated-Akt (pAkt), and mammalian target of rapamycin (mTOR) content. EMPA exhibited potent neuroprotective potential in DOX-induced cognitive impairment, attributed to its antioxidant and neuroplasticity-enhancing properties and suppression of the PI3K/Akt/mTOR/NF-κB/TNF-α signaling pathway.

Unveiling the mTOR pathway modulation by SGLT2 inhibitors: a novel approach to Alzheimer's disease in type 2 diabetes

Alzheimer's disease (AD) is a neurological condition causing cognitive deterioration, leading to severe consequences. As the global prevalence of AD increases, new treatment approaches are needed to supplement current conventional therapies, as traditional treatments are not meeting the increasing demand for alternative treatments. It is increasingly evident that treating metabolic disorders like diabetes mellitus, obesity, and AD by blocking mechanistic target of rapamycin (mTOR) signalling is advantageous. Chronic mTOR activation may cause AD's metabolic, lysosomal, and mitochondrial dysfunction, tau hyperphosphorylation, amyloid plaque development, and disruption of the blood-brain barrier through endothelial cell malfunction. Chronic glucose loss through sodium-glucose transporter 2 (SGLT2) inhibitions can restore mTOR cycling, potentially halting or slowing AD pathogenesis. Chronic activation of mTOR is implicated in pathophysiological aspects of AD, such as metabolic dysfunction, tau hyperphosphorylation, amyloid plaque formation, and disruption of the blood-brain barrier. SGLT-2 inhibitors, commonly used in treating Type 2 Diabetes, have been shown to reduce mTOR activation and restore circadian regularity, a new finding in cognitive decline and metabolic disorders. Conversely, SGLT2 inhibitors decrease oxidative damage, inflammation, insulin signaling pathways, and proliferation of endothelial cells to enhance vascular tone, flexibility, and contractility. Along with reducing the formation of plaque containing amyloid and improving brain function, neural plasticity, acetylcholinesterase (AChE) activity, damage to the brain, and cognitive decline, they also regulate the mTOR pathway in the brain. Thus, repurposing SGLT-2 inhibitors, primarily used in diabetes treatment, presents a promising avenue for changing the way that AD is managed. The purpose of this review was to focus on the mTOR signalling cascade of SGLT 2 inhibitors to AD management in Type 2 Diabetes mellitus.

SGLT2i and Cardiovascular Events in Patients With Concomitant Atrial Fibrillation and Diabetes: A TriNetX Cohort Study

AIMS

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) enhance cardiovascular outcomes in individuals with type 2 diabetes mellitus (T2DM). Whether such effects also occur in T2DM patients with atrial fibrillation (AF) remains unknown. We aimed to investigate SGLT2i use on cardiovascular outcomes in patients with concomitant AF and T2DM.

METHODS

Patients with both AF and T2DM were identified from TriNetX, an international electronic medical record. Participants were divided into 2 groups according to their use of SGLT2i, at a 1:1 distribution through propensity score matching (PSM). The hazard ratio (HR) for clinical outcomes was determined using multivariate Cox hazards regression model.

RESULTS

We studied 339 792 patients with AF and T2DM, with 32 945 (9.70%) SGLT2i users. Following PSM, 17 011 patients aged 68.4 ± 7.9 years were included in each group. After a 3-year follow-up, patients treated with SGLT2i showed significantly reduced risks of stroke (adjusted HR: 0.830, P < .001), dementia (adjusted HR: 0.662, P < .001), long-standing persistent AF (adjusted HR: 0.917, P < .001), heart failure (adjusted HR: 0.833, P < .001), and all-cause mortality (adjusted HR: 0.532, P < .001).

CONCLUSION

The use of SGLT2i was associated with reduced risks of stroke, dementia, long-standing persistent AF, heart failure, and mortality in patients with both AF and T2DM. SGLT2i may be considered as a potential first-line therapy for this population.

Blood Pressure Management Strategies and Podocyte Health

Hypertension (HTN) is one of the key global cardiovascular risk factors, which is tightly linked to kidney health and disease development. Podocytes, glomerular epithelial cells that play a pivotal role in maintenance of the renal filtration barrier, are significantly affected by increased glomerular capillary pressure in HTN. Damage or loss of these cells causes proteinuria, which marks the initiation of the HTN-driven renal damage. It goes without saying that effective blood pressure (BP) management should not only mitigate cardiovascular risks but also preserve renal function by protecting podocyte integrity. This review offers a comprehensive examination of current BP management strategies and their implications for podocyte structure and function and emphasizes strategies for the reduction of proteinuria in HTN. We explore primary and secondary antihypertensive agents, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, and diuretics, as well as newer therapies (sodium-glucose cotransporter-2 blocking and endothelin receptor antagonism), emphasizing their mechanistic roles in safeguarding podocytes and curtailing proteinuria.

Anti-diabetic agents and the risks of dementia in patients with type 2 diabetes: a systematic review and network meta-analysis of observational studies and randomized controlled trials

OBJECTIVE

To evaluate the association between anti-diabetic agents and the risks of dementia in patients with type 2 diabetes (T2D).

METHODS

Literature retrieval was conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrial.gov between January 1995 and October 2024. Observational studies and randomized controlled trials (RCTs) in patients with T2D, which intercompared anti-diabetic agents or compared them with placebo, and reported the incidence of dementia were included. Conventional and network meta-analyses of these studies were implemented. Results were exhibited as the odds ratio (OR) or risk ratio (RR) with 95% confidence interval (CI).

RESULTS

A total of 41 observational studies (3,307,483 participants) and 23 RCTs (155,443 participants) were included. In the network meta-analysis of observational studies, compared with non-users, sodium glucose cotransporter-2 inhibitor (SGLT-2i) (OR = 0.56, 95%CI, 0.45 to 0.69), glucagon-like peptide-1 receptor agonist (GLP-1RA) (OR = 0.58, 95%CI, 0.46 to 0.73), thiazolidinedione (TZD) (OR = 0.68, 95%CI, 0.57 to 0.81) and metformin (OR = 0.89, 95%CI, 0.80 to 0.99) treatments were all associated with reduced risk of dementia in patients with T2D. The surface under the cumulative ranking curve (SUCRA) evaluation conferred a rank order as SGLT-2i > GLP-1RA > TZD > dipeptidyl peptidase-4 inhibitor (DPP-4i) > metformin > α-glucosidase inhibitor (AGI) > glucokinase activator (GKA) > sulfonylureas > glinides > insulin in terms of the cognitive benefits. Meanwhile, compared with non-users, SGLT-2i (OR = 0.43, 95%CI, 0.30 to 0.62), GLP-1RA (OR = 0.54, 95%CI, 0.30 to 0.96) and DPP-4i (OR = 0.73, 95%CI, 0.57 to 0.93) were associated with a reduced risk of Alzheimer's disease while a lower risk of vascular dementia was observed in patients receiving SGLT-2i (OR = 0.42, 95%CI, 0.22 to 0.80) and TZD (OR = 0.52, 95%CI, 0.36 to 0.75) treatment. In the network meta-analysis of RCTs, the risks of dementia were comparable among anti-diabetic agents and placebo.

CONCLUSION

Compared with non-users, SGLT-2i, GLP-1RA, TZD and metformin were associated with the reduced risk of dementia in patients with T2D. SGLT-2i, and GLP-1RA may serve as the optimal choice to improve the cognitive prognosis in patients with T2D.

Empagliflozin-activated AMPK elicits neuroprotective properties in reserpine-induced depression via regulating dynamics of hippocampal autophagy/inflammation and PKCζ-mediated neurogenesis

RATIONALE

Major depression has been an area of extensive research during the last decades, for it represents a leading cause of disability and suicide. The stark rise of depression rates influenced by life stressors, economic threats, pandemic era, and resistance to classical treatments, has made the disorder rather challenging. Adult hippocampal neurogenesis and plasticity are particularly sensitive to the dynamic interplay between autophagy and inflammation. In fact, the intricate balance between the two processes contributes to neuronal homeostasis and survival.

OBJECTIVES

Having demonstrated promising potentials in AMPK activation, a major metabolic sensor and autophagy regulator, empagliflozin (Empa) was investigated for possible antidepressant properties in the reserpine rat model of depression.

RESULTS

While the reserpine protocol elicited behavioral, biochemical, and histopathological changes relevant to depression, Empa outstandingly hindered these pathological perturbations. Importantly, hippocampal autophagic response markedly declined with reserpine which disrupted the AMPK/mTOR/Beclin1/LC3B machinery and, conversely, neuro-inflammation prevailed under the influence of the NLRP3 inflammasome together with oxidative/nitrative stress. Consequently, AMPK-mediated neurotrophins secretion obviously deteriorated through PKCζ/NF-κB/BDNF/CREB signal restriction. Empa restored hippocampal monoamines and autophagy/inflammation balance, driven by AMPK activation. By promoting the atypical PKCζ phosphorylation (Thr403) which subsequently phosphorylates NF-κB at Ser311, AMPK successfully reinforced BDNF/CREB signal and hippocampal neuroplasticity. The latter finding was supported by hippocampal CA3 toluidine blue staining to reveal intact neurons.

CONCLUSION

The current study highlights an interesting role for Empa as a regulator of autophagic and inflammatory responses in the pathology of depression. The study also pinpoints an unusual contribution for NF-κB in neurotrophins secretion via AMPK/PKCζ/NF-κB/BDNF/CREB signal transduction. Accordingly, Empa can have special benefits in diabetic patients with depressive symptoms.

LIMITATIONS

The influence of p-NF-κB (Ser311) on NLRP3 inflammasome assembly and activation has not been investigated, which can represent an interesting point for further research.

Sodium-Glucose Cotransporter-2 Inhibitors, Dulaglutide, and Risk for Dementia : A Population-Based Cohort Study

BACKGROUND

Both sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may have neuroprotective effects in patients with type 2 diabetes (T2D). However, their comparative effectiveness in preventing dementia remains uncertain.

OBJECTIVE

To compare the risk for dementia between SGLT2 inhibitors and dulaglutide (a GLP-1 RA).

DESIGN

Target trial emulation study.

SETTING

Nationwide health care data of South Korea obtained from the National Health Insurance Service between 2010 and 2022.

PATIENTS

Patients aged 60 years or older who have T2D and are initiating treatment with SGLT2 inhibitors or dulaglutide.

MEASUREMENTS

The primary outcome was the presumed clinical onset of dementia. The date of onset was defined as the year before the date of dementia diagnosis, assuming that the time between the onset of dementia and diagnosis was 1 year. The 5-year risk ratios and risk differences comparing SGLT2 inhibitors with dulaglutide were estimated in a 1:2 propensity score-matched cohort adjusted for confounders.

RESULTS

Overall, 12 489 patients initiating SGLT2 inhibitor treatment (51.9% dapagliflozin and 48.1% empagliflozin) and 1075 patients initiating dulaglutide treatment were included. In the matched cohort, over a median follow-up of 4.4 years, the primary outcome event occurred in 69 participants in the SGLT2 inhibitor group and 43 in the dulaglutide group. The estimated risk difference was -0.91 percentage point (95% CI, -2.45 to 0.63 percentage point), and the estimated risk ratio was 0.81 (CI, 0.56 to 1.16).

LIMITATION

Residual confounding is possible; there was no adjustment for hemoglobin A1c levels or duration of diabetes; the study is not representative of newer drugs, including more effective GLP-1 RAs; and the onset of dementia was not measured directly.

CONCLUSION

Under conventional statistical criteria, a risk for dementia between 2.5 percentage points lower and 0.6 percentage point greater for SGLT2 inhibitors than for dulaglutide was estimated to be highly compatible with the data from this study. However, whether these findings generalize to newer GLP-1 RAs is uncertain. Thus, further studies incorporating newer drugs within these drug classes and better addressing residual confounding are required.

PRIMARY FUNDING SOURCE

Ministry of Food and Drug Safety of South Korea.

mTOR and SGLT-2 Inhibitors: Their Synergistic Effect on Age-Related Processes

The aging process contributes significantly to the onset of chronic diseases, which are the primary causes of global mortality, morbidity, and healthcare costs. Numerous studies have shown that the removal of senescent cells from tissues extends lifespan and reduces the occurrence of age-related diseases. Consequently, there is growing momentum in the development of drugs targeting these cells. Among them, mTOR and SGLT-2 inhibitors have garnered attention due to their diverse effects: mTOR inhibitors regulate cellular growth, metabolism, and immune responses, while SGLT-2 inhibitors regulate glucose reabsorption in the kidneys, resulting in various beneficial metabolic effects. Importantly, these drugs may act synergistically by influencing senescence processes and pathways. Although direct studies on the combined effects of mTOR inhibition and SGLT-2 inhibition on age-related processes are limited, this review aims to highlight the potential synergistic benefits of these drugs in targeting senescence.

Comprehensive Overview of Alzheimer's Disease: Etiological Insights and Degradation Strategies

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder and affects millions of individuals globally. AD is associated with cognitive decline and memory loss that worsens with aging. A statistical report using U.S. data on AD estimates that approximately 6.9 million individuals suffer from AD, a number projected to surge to 13.8 million by 2060. Thus, there is a critical imperative to pinpoint and address AD and its hallmark tau protein aggregation early to prevent and manage its debilitating effects. Amyloid-β and tau proteins are primarily associated with the formation of plaques and neurofibril tangles in the brain. Current research efforts focus on degrading amyloid-β and tau or inhibiting their synthesis, particularly targeting APP processing and tau hyperphosphorylation, aiming to develop effective clinical interventions. However, navigating this intricate landscape requires ongoing studies and clinical trials to develop treatments that truly make a difference. Genome-wide association studies (GWASs) across various cohorts identified 40 loci and over 300 genes associated with AD. Despite this wealth of genetic data, much remains to be understood about the functions of these genes and their role in the disease process, prompting continued investigation. By delving deeper into these genetic associations, novel targets such as kinases, proteases, cytokines, and degradation pathways, offer new directions for drug discovery and therapeutic intervention in AD. This review delves into the intricate biological pathways disrupted in AD and identifies how genetic variations within these pathways could serve as potential targets for drug discovery and treatment strategies. Through a comprehensive understanding of the molecular underpinnings of AD, researchers aim to pave the way for more effective therapies that can alleviate the burden of this devastating disease.

Glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, anti-diabetic drugs in heart failure and cognitive impairment: potential mechanisms of the protective effects

Heart failure and cognitive impairment emerge as public health problems that need to be addressed due to the aging global population. The conditions that often coexist are strongly related to advancing age and multimorbidity. Epidemiological evidence indicates that cardiovascular disease and neurodegenerative processes shares similar aspects, in term of prevalence, age distribution, and mortality. Type 2 diabetes increasingly represents a risk factor associated not only to cardiometabolic pathologies but also to neurological conditions. The pathophysiological features of type 2 diabetes and its metabolic complications (hyperglycemia, hyperinsulinemia, and insulin resistance) play a crucial role in the development and progression of both heart failure and cognitive dysfunction. This connection has opened to a potential new strategy, in which new classes of anti-diabetic medications, such as glucagon-like peptide-1 receptor (GLP-1R) agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors, are able to reduce the overall risk of cardiovascular events and neuronal damage, showing additional protective effects beyond glycemic control. The pleiotropic effects of GLP-1R agonists and SGLT2 inhibitors have been extensively investigated. They exert direct and indirect cardioprotective and neuroprotective actions, by reducing inflammation, oxidative stress, ions overload, and restoring insulin signaling. Nonetheless, the specificity of pathways and their contribution has not been fully elucidated, and this underlines the urgency for more comprehensive research.

Risk of Dementia in Patients with Diabetes Using Sodium-Glucose Transporter 2 Inhibitors (SGLT2i): A Systematic Review, Meta-Analysis, and Meta-Regression

INTRODUCTION

Dementia is quite prevalent and among the leading causes of death worldwide. According to earlier research, diabetes may increase the possibility of developing dementia. However, the association between antidiabetic agents and dementia is not yet clear. This investigation examines the association between the use of sodium-glucose transporter 2 inhibitors (SGLT2i) and the risk of dementia in patients with diabetes.

METHODS

Up to April 18, 2023, four databases-Europe PMC, Medline, Scopus, and Cochrane Library-were searched for relevant literature. We included all studies that examine dementia risk in adults with diabetes who use SGLT2i. Random-effect models were used to compute the outcomes in this investigation, producing pooled odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Pooled data from seven observational studies revealed that SGLT2i use was linked to a lower risk of dementia in people with diabetes (OR 0.45, 95% CI 0.34-0.61; p < 0.00001, I2 = 97%). The reduction in the risk of dementia due to SGLT2i's neuroprotective effect was only significantly affected by dyslipidemia (p = 0.0004), but not by sample size (p = 0.2954), study duration (p = 0.0908), age (p = 0.0805), sex (p = 0.5058), hypertension (p = 0.0609), cardiovascular disease (p = 0.1619), or stroke (p = 0.2734).

CONCLUSIONS

According to this research, taking SGLT2i reduces the incidence of dementia in people with diabetes by having a beneficial neuroprotective impact. Randomized controlled trials (RCTs) are still required in order to verify the findings of our research.

Cognitive Benefits of Sodium-Glucose Co-Transporters-2 Inhibitors in the Diabetic Milieu

Patients with diabetes are at higher risk of cognitive impairment and memory loss than the normal population. Thus, using hypoglycemic agents to improve brain function is important for diabetic patients. Sodium-glucose cotransporters-2 inhibitors (SGLT2i) are a class of therapeutic agents used in the management of diabetes that has some pharmacologic effects enabling them to fight against the onset and progress of memory deficits. Although the exact mediating pathways are not well understood, emerging evidence suggests that SGLT2 inhibition is associated with improved brain function. This study reviewed the possible mechanisms and provided evidence suggesting SGLT2 inhibitors could ameliorate cognitive deficits.

Preclinical Studies of Canagliflozin, a Sodium-Glucose Co-Transporter 2 Inhibitor, and Donepezil Combined Therapy in Alzheimer's Disease

The incidence of neurodegenerative diseases, such as Alzheimer's disease (AD), is continuously growing worldwide, which leads to a heavy economic and societal burden. The lack of a safe and effective causal therapy in cognitive decline is an aggravating factor and requires investigations into the repurposing of commonly used drugs. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are a new and efficient class of hypoglycemic drugs and, due to their pleiotropic effects, have indications that go beyond diabetes. There is emerging data from murine studies that SGLT2i can cross the blood-brain barrier and may have neuroprotective effects, such as increasing the brain-derived neurotrophic factor (BDNF), reducing the amyloid burden, inhibiting acetylcholinesterase (AChE) and restoring the circadian rhythm in the mammalian target of rapamycin (mTOR) activation. The current study investigates the effect of an SGLT2i and donepezil, under a separate or combined 21-day treatment on AD-relevant behaviors and brain pathology in mice. The SGLT2i canagliflozin was found to significantly improve the novelty preference index and the percentage of time spent in the open arms of the maze in the novel object recognition and elevated plus maze test, respectively. In addition, canagliflozin therapy decreased AChE activity, mTOR and glial fibrillary acidic protein expression. The results also recorded the acetylcholine M1 receptor in canagliflozin-treated mice compared to the scopolamine group. In the hippocampus, the SGLT2i canagliflozin reduced the microgliosis and astrogliosis in males, but not in female mice. These findings emphasize the value of SGLT2i in clinical practice. By inhibiting AChE activity, canagliflozin represents a compound that resembles AD-registered therapies in this respect, supporting the need for further evaluation in dementia clinical trials.

GLP-1 Analogs, SGLT-2, and DPP-4 Inhibitors: A Triad of Hope for Alzheimer's Disease Therapy

Alzheimer's is a prevalent, progressive neurodegenerative disease marked by cognitive decline and memory loss. The disease's development involves various pathomechanisms, including amyloid-beta accumulation, neurofibrillary tangles, oxidative stress, inflammation, and mitochondrial dysfunction. Recent research suggests that antidiabetic drugs may enhance neuronal survival and cognitive function in diabetes. Given the well-documented correlation between diabetes and Alzheimer's disease and the potential shared mechanisms, this review aimed to comprehensively assess the potential of new-generation anti-diabetic drugs, such as GLP-1 analogs, SGLT-2 inhibitors, and DPP-4 inhibitors, as promising therapeutic approaches for Alzheimer's disease. This review aims to comprehensively assess the potential therapeutic applications of novel-generation antidiabetic drugs, including GLP-1 analogs, SGLT-2 inhibitors, and DPP-4 inhibitors, in the context of Alzheimer's disease. In our considered opinion, antidiabetic drugs offer a promising avenue for groundbreaking developments and have the potential to revolutionize the landscape of Alzheimer's disease treatment.

Poly (ADP-Ribose) polymerase 1 and parthanatos in neurological diseases: From pathogenesis to therapeutic opportunities

Poly (ADP-ribose) polymerase-1 (PARP-1) is the most extensively studied member of the PARP superfamily, with its primary function being the facilitation of DNA damage repair processes. Parthanatos is a type of regulated cell death cascade initiated by PARP-1 hyperactivation, which involves multiple subroutines, including the accumulation of ADP-ribose polymers (PAR), binding of PAR and apoptosis-inducing factor (AIF), release of AIF from the mitochondria, the translocation of the AIF/macrophage migration inhibitory factor (MIF) complex, and massive MIF-mediated DNA fragmentation. Over the past few decades, the role of PARP-1 in central nervous system health and disease has received increasing attention. In this review, we discuss the biological functions of PARP-1 in neural cell proliferation and differentiation, memory formation, brain ageing, and epigenetic regulation. We then elaborate on the involvement of PARP-1 and PARP-1-dependant parthanatos in various neuropathological processes, such as oxidative stress, neuroinflammation, mitochondrial dysfunction, excitotoxicity, autophagy damage, and endoplasmic reticulum (ER) stress. Additional highlight contains PARP-1's implications in the initiation, progression, and therapeutic opportunities for different neurological illnesses, including neurodegenerative diseases, stroke, autism spectrum disorder (ASD), multiple sclerosis (MS), epilepsy, and neuropathic pain (NP). Finally, emerging insights into the repurposing of PARP inhibitors for the management of neurological diseases are provided. This review aims to summarize the exciting advancements in the critical role of PARP-1 in neurological disorders, which may open new avenues for therapeutic options targeting PARP-1 or parthanatos.

Molecular Research on Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia worldwide [...].

Molecular and neural roles of sodium-glucose cotransporter 2 inhibitors in alleviating neurocognitive impairment in diabetic mice

Diabetes causes a variety of molecular changes in the brain, making it a real risk factor for the development of cognitive dysfunction. Complex pathogenesis and clinical heterogeneity of cognitive impairment makes the efficacy of current drugs limited. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) gained our attention as drugs with potential beneficial effects on the CNS. In the present study, these drugs ameliorated the cognitive impairment associated with diabetes. Moreover, we verified whether SGLT2i can mediate the degradation of amyloid precursor protein (APP) and modulation of gene expression (Bdnf, Snca, App) involved in the control of neuronal proliferation and memory. The results of our research proved the participation of SGLT2i in the multifactorial process of neuroprotection. SGLT2i attenuate the neurocognitive impairment through the restoration of neurotrophin levels, modulation of neuroinflammatory signaling, and gene expression of Snca, Bdnf, and App in the brain of diabetic mice. The targeting of the above-mentioned genes is currently seen as one of the most promising and developed therapeutic strategies for diseases associated with cognitive dysfunction. The results of this work could form the basis of a future administration of SGLT2i in diabetics with neurocognitive impairment.

Brain insulin signaling and cognition: Possible links

Poor cognitive ability is a consequence of a wide variety of neurobehavioral disorders and is a growing health problem, especially among the elderly and patients with diabetes. The precise underlying cause of this complication is not well-defined. However, recent studies have highlighted the possible role of insulin hormone signaling in brain tissue. Insulin is a metabolic peptide integral to whole body energy homeostasis; it does, however, have extrametabolic impacts, such as upon neuronal circuits. Therefore, it has been suggested that insulin signaling may modify cognitive ability by yet unknown pathways. In the current review, we discuss the cognitive role of brain insulin signaling and consider the possible links between brain insulin signaling and cognitive ability.

Acteoside and ursolic acid synergistically protects H2O2-induced neurotrosis by regulation of AKT/mTOR signalling: from network pharmacology to experimental validation

CONTEXT

Ursolic acid (UA) and acteoside (ATS) are important active components that have been used to treat Alzheimer's disease (AD) because of their neuroprotective effects, but the exact mechanism is still unclear.

OBJECTIVE

Network pharmacology was used to explore the mechanism of UA + ATS in treating AD, and cell experiments were used to verify the mechanism.

MATERIALS AND METHODS

UA + ATS targets and AD-related genes were retrieved from TCMSP, STITCH, SwissTargetPrediction, GeneCards, DisGeNET and GEO. Key targets were obtained by constructing protein interaction network through STRING. The neuroprotective effects of UA + ATS were verified in H₂O₂-treated PC12 cells. The subsequent experiments were divided into Normal, Model (H₂O₂ pre-treatment for 4 h), Control (H₂O₂+ solvent pre-treatment), UA (5 μM), ATS (40 μM), UA (5 μM) + ATS (40 μM). Then apoptosis, mitochondrial membrane potential, caspase-3 activity, ATG5, Beclin-1 protein expression and Akt, mTOR phosphorylation levels were detected.

RESULTS

The key targets of UA + ATS-AD network were mainly enriched in Akt/mTOR pathway. Cell experiments showed that UA (ED₅₀: 5 μM) + ATS (ED₅₀: 40 μM) could protect H₂O₂-induced (IC₅₀: 250 μM) nerve damage by enhancing cells viability, combating apoptosis, restoring MMP, reducing the activation of caspase-3, lessening the phosphorylation of Akt and mTOR, and increasing the expression of ATG5 and Beclin-1.

CONCLUSIONS

ATS and UA regulates multiple targets, bioprocesses and signal pathways against AD pathogenesis. ATS and UA synergistically protects H₂O₂-induced neurotrosis by regulation of AKT/mTOR signalling.

Exploring the Involvement of the Amyloid Precursor Protein A673T Mutation against Amyloid Pathology and Alzheimer's Disease in Relation to Therapeutic Editing Tools

Alzheimer's disease (AD) is biologically defined as a complex neurodegenerative condition with a multilayered nature that leads to a progressive decline in cognitive function and irreversible neuronal loss. It is one of the primary diseases among elderly individuals. With an increasing incidence and a high failure rate for pharmaceutical options that are merely symptom-targeting and supportive with many side effects, there is an urgent need for alternative strategies. Despite extensive knowledge on the molecular basis of AD, progress concerning effective disease-modifying therapies has proven to be a challenge. The ability of the CRISPR-Cas9 gene editing system to help identify target molecules or to generate new preclinical disease models could shed light on the pathogenesis of AD and provide promising therapeutic possibilities. Here, we sought to highlight the current understanding of the involvement of the A673T mutation in amyloid pathology, focusing on its roles in protective mechanisms against AD, in relation to the recent status of available therapeutic editing tools.

Endocannabinoid Modulation in Neurodegenerative Diseases: In Pursuit of Certainty

Simple Summary

Neurodegenerative diseases represent an important cause of morbidity and mortality worldwide. Existing therapeutic options are limited and focus mostly on improving symptoms and reducing exacerbations. The endocannabinoid system is involved in the pathophysiology of such disorders, an idea which has been highlighted by recent scientific work. The current work focusses its attention on the importance and implications of this system and its synthetic and natural ligands in disorders such as Alzheimer’s, Parkinson’s, Huntington’s and multiple sclerosis.

Abstract

Neurodegenerative diseases are an increasing cause of global morbidity and mortality. They occur in the central nervous system (CNS) and lead to functional and mental impairment due to loss of neurons. Recent evidence highlights the link between neurodegenerative and inflammatory diseases of the CNS. These are typically associated with several neurological disorders. These diseases have fundamental differences regarding their underlying physiology and clinical manifestations, although there are aspects that overlap. The endocannabinoid system (ECS) is comprised of receptors (type-1 (CB1R) and type-2 (CB2R) cannabinoid-receptors, as well as transient receptor potential vanilloid 1 (TRPV1)), endogenous ligands and enzymes that synthesize and degrade endocannabinoids (ECBs). Recent studies revealed the involvement of the ECS in different pathological aspects of these neurodegenerative disorders. The present review will explore the roles of cannabinoid receptors (CBRs) and pharmacological agents that modulate CBRs or ECS activity with reference to Alzheimer’s Disease (AD), Parkinson’s Disease (PD), Huntington’s Disease (HD) and multiple sclerosis (MS).

Chemical Composition and Antioxidant Activity of Ammi visnaga L. Essential Oil

The present study evaluated the chemical composition and the in vitro and in vivo antioxidant potential of Ammi visnaga L. essential oil to provide a scientific basis for the use of this plant in the traditional pharmacopoeia. Gas chromatography-mass spectrometry was used to identify the volatile constituents present of the oil. The in vitro antioxidant capacity was evaluated by the DPPH and the reducing power assays. For the in vivo tests, oral administration of Ammi visnaga L. oil (600 and 1200 mg/kg body weight) was performed in Swiss albino mice treated with acetaminophen (400 mg/kg). The toxic effect of acetaminophen and the action of the essential oil were measured by determining the levels of lipid peroxidation and antioxidant enzymes in liver and kidneys homogenates. The major components identified were butanoic acid, 2-methyl-, pentyl ester, (Z)-β-ocimene, D-limonene, linalool, pulegone and lavandulyl-butyrate. The in vitro DPPH and reducing power assays showed moderate to low free radical scavenging activity and the antioxidant power was positively correlated with the polyphenols' concentration. In vivo, the Ammi visnaga L. essential oil showed a high antioxidant capacity at both concentrations (600 and 1200 mg/kg), effectively increasing the levels of reduced glutathione, superoxide dismutase, and catalase and significantly reducing the lipid peroxidation. The results obtained from this study suggest that Ammi visnaga L. could represent a source of molecules with antioxidant potential in the prevention of free radical-related diseases.

Comprehensive investigation of molecular signatures and pathways linking Alzheimer's disease and Epilepsy via bioinformatic approaches

BACKGROUND

Epileptic activity is frequent in patients with Alzheimer's disease (AD), and this may accelerate AD progression; however, the relationship between AD and epilepsy remains unclear.

OBJECTIVE

We aimed to investigate the molecular pathways and genes linking AD and epilepsy using bioinformatics approaches.

METHODS

Gene expression profiles of AD (GSE1297) and epilepsy (GSE28674) were derived from the Gene Expression Omnibus (GEO) database. The top 50% expression variants were subjected to weighted gene co-expression network analysis (WGCNA) to identify key modules associated with these diseases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for the key modules were performed, and the intersected terms of functional enrichment and common genes within the key modules were selected. The overlapping genes were subjected to analyses of protein-protein interaction (PPI) network, transcription factor (TF)-mRNA network, microRNA (miRNA)-mRNA network, and drug prediction.

RESULTS

We identified 229 and 1187 genes in the AD-associated purple and epilepsy-associated blue modules, respectively. Six shared functional terms between the two modules included "calcium ion binding" and "calcium signaling pathway." According to 17 common genes discovered, 130 TF-mRNA pairs and 56 miRNA-mRNA pairs were established. The topological analyses of the constructed regulatory networks suggested that TF - FOXC1 and miRNA - hsa-mir-335-5p might be vital co-regulators of gene expression in AD and epilepsy. In addition, CXCR4 was identified as a hub gene, becoming the putative target for 20 drugs.

CONCLUSION

Our study provided novel insights into the molecular connection between AD and epilepsy, which might be beneficial for exploring shared mechanisms and designing disease-modifying therapies.

Cognitive impairment and type 2 diabetes mellitus: Focus of SGLT2 inhibitors treatment

Gliflozins are a novel class of oral anti-diabetic drugs, acting as inhibitors of sodium-glucose co-transporters (SGLTs) through the proximal convoluted tubules (PCT) and intestinal epithelium. The sodium-glucose co-transporters 2 (SGLT2) are mainly expressed in S1 and S2 segments of the proximal convoluted tubule in the kidneys. Clinical guidelines recommend their use especially in Type 2 Diabetes mellitus (T2DM) patients with vascular complications and/or heart failure highlighting the importance of sodium-glucose co-transporter 2 inhibitors (SGLT2i) pleiotropic effects. Interestingly, cognitive decline is a widely recognized complication of T2DM and, in addition, to clarify its pathophysiology, there is an urgent need to understand how and if diabetes therapies can control diabetes-related cognitive dysfunction. At the time, although SGLT2 proteins are present in the Central Nervous System (CNS), the SGLT2i effects on cognitive impairments remain partly unknown. In pre-clinical studies, SGLT2i ameliorates cognitive dysfunction in obese and T2DM mice, reducing oxidative stress, neuroinflammation and improving neuronal plasticity and mitochondrial brain pathway. In addition, SGLT2i could bring back mTOR to a physiological state of activation, stopping neurodegenerative diseases' onset or progression. Instead, clinical studies on T2DM-related cognitive dysfunction treated by SGLT2i are much more limited. For these reasons, further studies are needed to better elucidate if SGLT2i therapy can affect T2DM-related cognitive decline. In this scenario, this review aims to summarize the state of knowledge on the role of SGLT2i in T2DM-related cognitive dysfunction and stimulate new clinical trials.

New treatment approaches for Alzheimer's disease: preclinical studies and clinical trials centered on antidiabetic drugs

INTRODUCTION

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) represent two major chronic diseases that affect a large percentage of the population and share common pathogenetic mechanisms, including oxidative stress and inflammation. Considering their common mechanistic aspects, and given the current lack of effective therapies for AD, accumulating research has focused on the therapeutic potential of antidiabetic drugs in the treatment or prevention of AD.

AREAS COVERED

This review examines the latest preclinical and clinical evidence on the potential of antidiabetic drugs as candidates for AD treatment. Numerous approved drugs for T2DM, including insulin, metformin, glucagon-like peptide-1 receptor agonists (GLP-1 RA), and sodium glucose cotransporter 2 inhibitors (SGLT2i), are in the spotlight and may constitute novel approaches for AD treatment.

EXPERT OPINION

Among other pharmacologic agents, GLP-1 RA and SGLT2i have so far exhibited promising results as novel treatment approaches for AD, while current research has centered on deciphering their action on the central nervous system (CNS). Further investigation is crucial to reveal the most effective pharmacological agents and their optimal combinations, maximize their beneficial effects on neurons, and find ways to increase their distribution to the CNS.

Neuroprotective Effect of SGLT2 Inhibitors

Patients with diabetes are at higher risk of cardiovascular diseases and cognitive impairment. SGLT2 inhibitors (Empagliflozin, Canagliflozin, Dapagliflozin, Ertugliflozin, Sotagliflozin) are newer hypoglycemic agents with many pleiotropic effects. In this review, we discuss their neuroprotective potential. SGLT2 inhibitors (SGLT2i) are lipid-soluble and reach the brain/serum ratio from 0.3 to 0.5. SGLT receptors are present in the central nervous system (CNS). Flozins are not fully SGLT2-selective and have an affinity for the SGLT1 receptor, which is associated with protection against ischemia/reperfusion brain damage. SGLT2i show an anti-inflammatory and anti-atherosclerotic effect, including reduction of proinflammatory cytokines, M2 macrophage polarization, JAK2/STAT1 and NLRP3 inflammasome inhibition, as well as cIMT regression. They also mitigate oxidative stress. SGLT2i improve endothelial function, prevent remodeling and exert a protective effect on the neurovascular unit, blood-brain barrier, pericytes, astrocytes, microglia, and oligodendrocytes. Flozins are also able to inhibit AChE, which contributes to cognitive improvement. Empagliflozin significantly increases the level of cerebral BDNF, which modulates neurotransmission and ensures growth, survival, and plasticity of neurons. Moreover, they may be able to restore the circadian rhythm of mTOR activation, which is quite a novel finding in the field of research on metabolic diseases and cognitive impairment. SGLT2i have a great potential to protect against atherosclerosis and cognitive impairment in patients with type 2 diabetes mellitus.

Major Phytocannabinoids and Their Related Compounds: Should We Only Search for Drugs That Act on Cannabinoid Receptors?

The most important discoveries in pharmacology, such as certain classes of analgesics or chemotherapeutics, started from natural extracts which have been found to have effects in traditional medicine. Cannabis, traditionally used in Asia for the treatment of pain, nausea, spasms, sleep, depression, and low appetite, is still a good candidate for the development of new compounds. If initially all attention was directed to the endocannabinoid system, recent studies suggest that many of the clinically proven effects are based on an intrinsic chain of mechanisms that do not necessarily involve only cannabinoid receptors. Recent research has shown that major phytocannabinoids and their derivatives also interact with non-cannabinoid receptors such as vanilloid receptor 1, transient receptor ankyrin 1 potential, peroxisome proliferator-activated receptor-gamma or glitazone receptor, G55 protein-coupled receptor, and nuclear receptor, producing pharmacological effects in diseases such as Alzheimer's, epilepsy, depression, neuropathic pain, cancer, and diabetes. Nonetheless, further studies are needed to elucidate the precise mechanisms of these compounds. Structure modulation of phytocannabinoids, in order to improve pharmacological effects, should not be limited to the exploration of cannabinoid receptors, and it should target other courses of action discovered through recent research.