Diana Barrera-Oviedo

Ischemic stroke is a leading cause of death and long-term disability worldwide. It results from cerebral blood flow obstruction (ischemia) and, in some cases, the restoration of cerebral blood flow (reperfusion), triggering a cascade of pathophysiological events collectively known as the ischemic cascade and reperfusion injury, which leads to the activation of different regulated cell death types, and this review focuses on necroptosis and ferroptosis. Both pathways are closely linked to oxidative stress and contribute significantly to neuronal death and inflammation following ischemic stroke. Dysregulation of redox homeostasis, iron dyshomeostasis, glutathione depletion, and mitochondrial dysfunction are key events in neuronal damage. Understanding the interplay between oxidative stress and these pathways is crucial for developing effective neuroprotective therapies. This review highlights recent advances in understanding necroptosis and ferroptosis in ischemic stroke, proposing redox-targeted interventions as promising strategies to mitigate brain injury and improve outcomes in patients affected by this condition.

Background/Objectives: Ischemic stroke is a leading cause of death and disability, and neuroprotection therapies, or those that increase recovery, are not available. While the garlic-derived bioactive compound S-allyl cysteine (SAC) has shown neuroprotective properties, its subacute long-term effects remain underexplored, particularly in females. Methods: We evaluated whether SAC supports functional recovery after ischemia/reperfusion (IR), focusing on neurotrophin signaling, tropomyosin receptor kinase B (TrkB), protein kinase B (AKT), and extracellular signal-regulated kinase (ERK). Adult female Wistar rats underwent 1 h of ischemia and 15 days of reperfusion. SAC (100 mg/kg, i.p.) was administered at the onset of reperfusion and daily for 15 days. Motor and cognitive deficit tests were performed. Infarct area, Ki67, brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF), pTrkB, pAKT, and pERK levels were quantified in the cortex, striatum, and hippocampus. Results: MicroPET analysis revealed comparable glucose uptake between the IR and IR + SAC groups, indicating similar ischemic severity. SAC reduced infarct area (54.7%) and significantly improved motor deficits (53.9%), circling behavior (38.9%), and long-term memory compared with ischemia/reperfusion (IR) animals. SAC increased the proportion of Ki67-positive cells (4.3-fold in the cortex and 1.8-fold in the striatum) and enhanced neurotrophin levels, NGF (cortex), BDNF (cortex and striatum), VEGF (striatum), pTrkB, pAKT, and pERK (cortex and striatum). Conclusions: SAC supports post-ischemic recovery, improving motor performance and preserving long-term recognition memory, effects that could be associated with increased cell proliferation, neurotrophin levels, and activation of the TrkB, AKT, and ERK pathways.

Ionic channels are present in eucaryotic plasma and intracellular membranes. They coordinate and control several functions. Potassium channels belong to the most diverse family of ionic channels that includes ATP-dependent potassium (KATP) channels in the potassium rectifier channel subfamily. These channels were initially described in heart muscle and then in other tissues such as pancreatic, skeletal muscle, brain, and vascular and non-vascular smooth muscle tissues. In pancreatic beta cells, KATP channels are primarily responsible for maintaining the membrane potential and for depolarization-mediated insulin release, and their decreased density and activity may be related to insulin resistance. KATP channels’ relationship with insulin resistance is beginning to be explored in extra-pancreatic beta tissues like the skeletal muscle, where KATP channels are involved in insulin-dependent glucose recapture and their activation may lead to insulin resistance. In adipose tissues, KATP channels containing Kir6.2 protein subunits could be related to the increase in free fatty acids and insulin resistance; therefore, pathological processes that promote prolonged adipocyte KATP channel inhibition might lead to obesity due to insulin resistance. In the central nervous system, KATP channel activation can regulate peripheric glycemia and lead to brain insulin resistance, an early peripheral alteration that can lead to the development of pathologies such as obesity and Type 2 Diabetes Mellitus (T2DM). In this review, we aim to discuss the characteristics of KATP channels, their relationship with clinical disorders, and their mechanisms and potential associations with peripheral and central insulin resistance.

Ionic channels are present in eucaryotic plasmatic and intracellular membranes. They coordinate and control several functions. One of the most diverse ionic channels family are the potassium (K) channels. Within this family are the ATP-dependent potassium channels (KATP), which belong to the potassium rectifier channel family. These channels were initially described in heart muscle, yet they are also present in different types of tissues such as pancreatic, skeletal muscle, brain, and vascular and non-vascular smooth muscle. In ß-pancreatic cells, KATP are primarily responsible for maintaining membrane potential and for the depolarization mediated insulin release. KATP density/activity seems to be determinant in physiological the outcome, in pancreatic cells decrease of this density/activity may be related to Insulin resistance (IR). In extra pancreatic tissues KATP relation with IR is beginning to be explored. It is possible that in skeletal muscle, the KATP are involved in insulin dependent glucose recapture and that KATP activation leads to IR. In adipose tissue, KATP containing Kir6.2, could be related to increase in free fatty acids and insulin resistance, therefore, pathological processes leading to a prolonged adipocyte KATP inhibition might promote obesity related to insulin resistance. In central nervous system KATP activation can regulate peripheric glycemia and lead to brain IR which could be a much earlier manifestation of peripheral alterations that lead to the development of pathologies such as obesity and type 2 diabetes mellitus. In this review we aim to discuss the KATP channel characteristics, its relationship to known clinical disorders and the mechanisms and potential relations with peripheral and central insulin resistance.

Stroke represents one of the main causes of death and disability in the world; despite this, pharmacological therapies against stroke remain insufficient. Ischemic stroke is the leading etiology of stroke. Different molecular mechanisms, such as excitotoxicity, oxidative stress, and inflammation, participate in cell death and tissue damage. At a preclinical level, different garlic compounds have been evaluated against these mechanisms. Additionally, there is evidence supporting the participation of garlic compounds in other mechanisms that contribute to brain tissue recovery, such as neuroplasticity. After ischemia, neuroplasticity is activated to recover cognitive and motor function. Some garlic-derived compounds and preparations have shown the ability to promote neuroplasticity under physiological conditions and, more importantly, in cerebral damage models. This work describes damage/repair mechanisms and the importance of garlic as a source of antioxidant and anti-inflammatory agents against damage. Moreover, we examine the less-explored neurotrophic properties of garlic, culminating in proposals and observations based on our review of the available information. The aim of the present study is to propose that garlic compounds and preparations could contribute to the treatment of ischemic stroke through their neurotrophic effects.