Simvastatin Displays an Antioxidative Effect by Inhibiting an Increase in the Serum 8-Isoprostane Level in Patients With Acute Ischemic Stroke: Brief Report

Antioxidants and Dementia Risk: Consideration through a Cerebrovascular Perspective

A number of natural and chemical compounds that exert anti-oxidative properties are demonstrated to be beneficial for brain and cognitive function, and some are reported to reduce the risk of dementia. However, the detailed mechanisms by which those anti-oxidative compounds show positive effects on cognition and dementia are still unclear. An emerging body of evidence suggests that the integrity of the cerebrovascular blood-brain barrier (BBB) is centrally involved in the onset and progression of cognitive impairment and dementia. While recent studies revealed that some anti-oxidative agents appear to be protective against the disruption of BBB integrity and structure, few studies considered the neuroprotective effects of antioxidants in the context of cerebrovascular integrity. Therefore, in this review, we examine the mechanistic insights of antioxidants as a pleiotropic agent for cognitive impairment and dementia through a cerebrovascular axis by primarily focusing on the current available data from physiological studies. Conclusively, there is a compelling body of evidence that suggest antioxidants may prevent cognitive decline and dementia by protecting the integrity and function of BBB and, indeed, further studies are needed to directly examine these effects in addition to underlying molecular mechanisms.

Oxidative stress in severe acute illness

The overall redox potential of a cell is primarily determined by oxidizable/reducible chemical pairs, including glutathione–glutathione disulfide, reduced thioredoxin–oxidized thioredoxin, and NAD⁺–NADH (and NADP–NADPH). Current methods for evaluating oxidative stress rely on detecting levels of individual byproducts of oxidative damage or by determining the total levels or activity of individual antioxidant enzymes. Oxidation–reduction potential (ORP), on the other hand, is an integrated, comprehensive measure of the balance between total (known and unknown) pro-oxidant and antioxidant components in a biological system. Much emphasis has been placed on the role of oxidative stress in chronic diseases, such as Alzheimer's disease and atherosclerosis. The role of oxidative stress in acute diseases often seen in the emergency room and intensive care unit is considerable. New tools for the rapid, inexpensive measurement of both redox potential and total redox capacity should aid in introducing a new body of literature on the role of oxidative stress in acute illness and how to screen and monitor for potentially beneficial pharmacologic agents.

Association between statin use and short-term outcome based on severity of ischemic stroke: a cohort study

BACKGROUND

Statins reportedly improve clinical outcomes for ischemic stroke patients. However, it is unclear whether the contribution of statin treatment varies depending on the severity of stroke. We sought to investigate the relationship between statin use and the outcome of acute first-ever ischemic stroke patients stratified by stroke severity.

METHODS

A total of 7,455 acute first-ever ischemic stroke patients without statin treatment before onset were eligible from the China National Stroke Registry. A National Institutes of Health Stroke Scale (NIHSS) score of 0 to 4 was defined as minor stroke, and a NIHSS score of >4 was defined as non-minor stroke. We analyzed the association between statin use during hospitalization and mortality as well as functional outcome (measured by a modified Rankin Scale score of 0-5) at 3 months after onset using multivariable logistic regression models.

RESULTS

A total of 3,231 (43.3%) patients received statin treatment during hospitalization. Multivariable analysis showed that statin use during hospitalization decreased mortality of ischemic stroke patients (OR, 0.51; 95%CI, 0.38-0.67), but did not improve poor functional outcomes (OR, 0.95; 95CI%, 0.81-1.11) at 3 months. The interaction between statin use and stroke severity was significant both in dependence and death outcome (P = 0.04 for dependence outcome, P = 0.03 for death outcome). After stratification by stroke severity, statin use during hospitalization decreased the mortality of stroke (OR, 0.44; 95%CI, 0.31-0.62) and poor functional outcome (OR, 0.73; 95%CI, 0.57-0.92) at 3 months in the non-minor stroke group.

CONCLUSIONS

Statin use during hospitalization may improve the clinical outcome of acute first-ever ischemic stroke depending on the severity of stroke. Non-minor stroke patients may obtain benefit from statin treatment with improvements in poor functional outcomes and mortality.

The significance of matrix metalloproteinase (MMP)-2 and MMP-9 in the ischemic stroke

There is a continuous urgent need to explore the pathogenesis and biochemical changes within the infarcted area during acute ischemic stroke (IS). Matrix metalloproteinases (MMPs), prevailing extracellular endopeptideses, can digest proteins located extracellulary, e.g. collagen, proteoglycans, elastin or fibronectin. Among MMPs, gelatinases (MMP-2 and MMP-9) are the most investigated enzymes. Gelatinases possess the ability to active numerous pro-inflammatory agents as chemokine CXCL-8, interleukin 1β or tumor necrosis factor α. Moreover, due to digestion of collagen type IV (the component of basal membranes) and tight junction proteins (TJPs) they facilitate to cross the endothelium by leukocytes. Due to the significant role of gelatinases during brain ischemia, their selective inhibition seems to be an interesting kind of treatment of acute stroke. The synthetic inhibitors of gelatineses decrease the infarct volume in animal models of IS. In clinical practice statins, the lipid-lowering drugs possess the ability to inhibit the activity of MMP-9 during acute IS. This review briefly provides the most important information about the involvement of MMP-2 and MMP-9 in the pathogenesis of brain ischemia.