Pretreatment with bisoprolol and vitamin E alone or in combination provides neuroprotection against cerebral ischemia/reperfusion injury in rats

MPO and its role in cancer, cardiovascular and neurological disorders: An update

Myeloperoxidase (MPO) is an enzyme that contains a heme group, found mostly in neutrophils and in small amounts in monocytes and plays a major role in their anti-microbial activity. However, excessive levels of MPO have been linked to various disorders and identified as a major cause of tissue destruction. Inhibiting its activity can reduce the severity and extent of tissue damage. Over activity of MPO during chronic inflammation has been shown to be involved in tumorigenesis by inducing a hyper-mutagenic environment through oxidant interaction with DNA, causing DNA modification. Vascular endothelium is one of the most important targets of MPO and high levels have been associated with increased rates of cardiomyopathy, ischemic stroke, heart failure, myocardial infarction, and atrial fibrillation. Therefore, it may be considered a therapeutic target in the treatment of cardiovascular disorders. MPO also participates in the pathogenesis of neurodegenerative diseases. For example, an increase in MPO levels has been observed in the brain tissue of patients with Alzheimer's, Multiple sclerosis (MS), and Parkinson's diseases. In Alzheimer's disease, active MPO is mostly found in the location of beta amyloids and microglia. Therefore, targeting MPO may be a potential treatment and prevention strategy for neurological disorders. This review will discuss MPO's physiological and pathological role in cancer, cardiovascular, and neurological disorders.

Interactions Between Ferroptosis and Oxidative Stress in Ischemic Stroke

Ischemic stroke is a devastating condition that occurs due to the interruption of blood flow to the brain, resulting in a range of cellular and molecular changes. In recent years, there has been growing interest in the role of ferroptosis, a newly identified form of regulated cell death, in ischemic stroke. Ferroptosis is driven by the accumulation of lipid peroxides and is characterized by the loss of membrane integrity. Additionally, oxidative stress, which refers to an imbalance between prooxidants and antioxidants, is a hallmark of ischemic stroke and significantly contributes to the pathogenesis of the disease. In this review, we explore the interactions between ferroptosis and oxidative stress in ischemic stroke. We examine the underlying mechanisms through which oxidative stress induces ferroptosis and how ferroptosis, in turn, exacerbates oxidative stress. Furthermore, we discuss potential therapeutic strategies that target both ferroptosis and oxidative stress in the treatment of ischemic stroke. Overall, this review highlights the complex interplay between ferroptosis and oxidative stress in ischemic stroke and underscores the need for further research to identify novel therapeutic targets for this condition.

Neuroprotective effects of ivermectin against transient cerebral ischemia-reperfusion in rats

Stroke is a leading cause of disability and death worldwide. Ivermectin is a broad-spectrum anti-parasitic agent with potential anti-bacterial, anti-viral, and anti-cancer effects. However, the effects of ivermectin on the brain are poorly described. This study examined the effects of ivermectin on cerebral ischemia-reperfusion (IR) in rats. A rat model of transient global IR was induced by bilateral carotid artery occlusion for 20 min. Rats received ivermectin (2 mg/kg/day, ip) one hour after inducing cerebral IR for three consecutive days at 24-h intervals. Next, we examined the effects of ivermectin on brain infarction, histopathology, malondialdehyde levels, myeloperoxidase activity, spatial learning and memory, and phospho-AMPK protein levels. The results showed that ivermectin reduced brain infarct size (P < 0.001) and histopathological changes such as cerebral leukocyte accumulation and edema (P < 0.05) compared to untreated rats with IR. Treatment with ivermectin also decreased myeloperoxidase activity (P < 0.01) and malondialdehyde levels (P < 0.05) while increasing AMPK activity (P < 0.001), memory, and learning compared to the untreated IR group. Overall, we show for the first time that ivermectin conferred neuroprotective effects in a rat model of cerebral IR. Our results indicate that three days of treatment with ivermectin reduced brain infarct size, lipid peroxidation, and myeloperoxidase activity and improved memory and learning in rats with cerebral IR. These effects likely occurred via AMPK-dependent mechanisms.

Potential Role of Natural Antioxidants in Countering Reperfusion Injury in Acute Myocardial Infarction and Ischemic Stroke

Stroke and acute myocardial infarction are leading causes of mortality worldwide. The latter accounts for approximately 9 million deaths annually. In turn, ischemic stroke is a significant contributor to adult physical disability globally. While reperfusion is crucial for tissue recovery, it can paradoxically exacerbate damage through oxidative stress (OS), inflammation, and cell death. Therefore, it is imperative to explore diverse approaches aimed at minimizing ischemia/reperfusion injury to enhance clinical outcomes. OS primarily arises from an excessive generation of reactive oxygen species (ROS) and/or decreased endogenous antioxidant potential. Natural antioxidant compounds can counteract the injury mechanisms linked to ROS. While promising preclinical results, based on monotherapies, account for protective effects against tissue injury by ROS, translating these models into human applications has yielded controversial evidence. However, since the wide spectrum of antioxidants having diverse chemical characteristics offers varied biological actions on cell signaling pathways, multitherapy has emerged as a valuable therapeutic resource. Moreover, the combination of antioxidants in multitherapy holds significant potential for synergistic effects. This study was designed with the aim of providing an updated overview of natural antioxidants suitable for preventing myocardial and cerebral ischemia/reperfusion injuries.

The Promising Effect of Topiramate on Random-Pattern Skin Flap Survival in Rats

BACKGROUND

Partial necrosis of skin flaps following plastic and reconstructive surgeries is one of the major problems in these medical interventions. This study was conducted to evaluate the beneficial effects of topiramate an anti-epileptic agent on ischemic random skin flaps.

MATERIALS AND METHODS

Twenty-four Wistar rats were provided and randomly divided into four experimental groups (control group and low-, intermediate- and high-dose treatment groups). A rat random-pattern skin flap model was performed in all groups, and animals in the low-, intermediate- and high-dose experimental groups were administered topiramate intraperitoneally at doses of 25, 50 and 100 mg/kg, respectively, 1 h before raising the flap and once daily for 7 consecutive days after the initial surgical procedure. Control rats received vehicle according to the same schedule. On postoperative day 7 the flap necrotic area was measured, and tissue samples were stained with hematoxylin and eosin for histological analysis. Furthermore, the oxidative stress in flap tissue was assessed by measuring the activity of superoxide dismutase (SOD), glutathione (GSH) level and the content of malondialdehyde (MDA).

RESULTS

Treating animals with 50 and 100 mg/kg topiramate significantly decreased the necrotic flap areas as compared to the control group. Histological studies demonstrated that in intermediate and high dose topiramate groups the inflammatory cell numbers were attenuated and microvessel development were markedly increased. Furthermore, the MDA contents were significantly reduced and GSH levels were significantly increased in these groups as compared to the control group. However, the SOD activity was increased significantly only in high-dose group as compared to the control group.

CONCLUSIONS

These findings indicated that topiramate in doses of 50 and 100 mg/kg increases random skin flap survival.

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