Vasodilator effects of sulforaphane in cerebral circulation: A critical role of endogenously produced hydrogen sulfide and arteriolar smooth muscle KATP and BK channels in the brain

Hydrogen Sulfide can Scavenge Free Radicals to Improve Spinal Cord Injury by Inhibiting the p38MAPK/mTOR/NF-κB Signaling Pathway

Spinal cord injury (SCI) causes irreversible cell loss and neurological dysfunctions. Presently, there is no an effective clinical treatment for SCI. It can be the only intervention measure by relieving the symptoms of patients such as pain and fever. Free radical-induced damage is one of the validated mechanisms in the complex secondary injury following primary SCI. Hydrogen sulfide (H2S) as an antioxidant can effectively scavenge free radicals, protect neurons, and improve SCI by inhibiting the p38MAPK/mTOR/NF-κB signaling pathway. In this report, we analyze the pathological mechanism of SCI, the role of free radical-mediated the p38MAPK/mTOR/NF-κB signaling pathway in SCI, and the role of H2S in scavenging free radicals and improving SCI.

Dual-channel fluorescent probe for discriminative detection of H2S and N2H4: Exploring sensing mechanism and real-time applications

A highly efficient system incorporates the real-time visualization of the two toxic molecules (H2S and N2H4) and the recognition of corresponding transforms using a fluorescent sensor. In this paper, a dual-responsive probe (QS-DNP) based on methylquinolinium-salicyaldehyde-2,4-dinitrophenyl was developed that can simultaneously detect H2S and N2H4 at two independent fluorescent channels without signal crosstalk. QS-DNP showed excellent anti-interference, high selectivity, outstanding water solubility, low LOD values (H2S: 51 nM; N2H4: 40 nM), low cytotoxicity, and mitochondrial localization properties. The 2,4-dinitrophenyl site was sensitive to H2S, and the CC bridge was reactive to N2H4, with strong fluorescence at 680 and 488 nm, respectively. The wavelength gap between these two channels is 192 nm; verify that there is no signal crosstalk throughout detection. By this means, the probe was used to simultaneously detect H2S and N2H4 in real soil samples, food samples, and living cells. The endogenous H2S and N2H4 were monitored in HeLa cells and investigated the mitochondria organelle of living cells with a positive charge on QS-DNP. Overall, all results emphasize that the QS-DNP probe is a powerful tool for the simultaneous detection of H2S and N2H4 and presents a potential new sensing approach.

Preeclampsia to COVID-19: A journey towards improved placental and vascular function using sulforaphane

Excess inflammation and oxidative stress are common themes in many pathologies of pregnancy including preeclampsia and more recently severe COVID-19. The risk of preeclampsia increases following maternal infection with COVID-19, potentially relating to significant overlap in pathophysiology with endothelial, vascular and immunological dysfunction common to both. Identifying a therapy which addresses these injurious processes and stabilises the endothelial and vascular maternal system would help address the significant global burden of maternal and neonatal morbidity and mortality they cause. Sulforaphane is a naturally occurring phytonutrient found most densely within cruciferous vegetables. It has anti-inflammatory, antioxidant and immune modulating properties via upregulation of phase-II detoxification enzymes. This review will cover the common pathways shared by COVID-19 and preeclampsia and offer a potential therapeutic target via nuclear factor erythroid 2-related factor upregulation in the form of sulforaphane.

Cerebroprotective actions of hydrogen sulfide in the epileptic brain in newborn pigs

BACKGROUND

Neonatal epileptic seizures cause postictal dysregulation of cerebral blood flow. Hydrogen sulfide (H₂S), a mediator with vasodilator and antioxidant properties, is produced in the brain by astrocyte cystathionine β-synthase (CBS). This study investigated whether H₂S improves the cerebral vascular outcome of seizures.

METHODS

Epileptic seizures were induced in newborn pigs using bicuculline. The effects of the CBS inhibitor aminooxyacetate (AOA) and the H₂S donor NaHS on cerebral vascular outcome of seizures were examined in live pigs, cerebral endothelial cells, and cortical astrocytes.

RESULTS

Brain H₂S was elevated during seizures. AOA blocked H₂S and reduced functional hyperemia in the epileptic brain. The endothelium- and astrocyte-dependent vasodilation of pial arterioles was impaired 48 h after seizures suggesting cerebral vascular dysfunction. Systemic NaHS elevated brain H₂S and blocked reactive oxygen species in the epileptic brain and in primary endothelial cells and astrocytes during inflammatory and excitotoxic conditions. Postictal cerebrovascular dysfunction was exaggerated in H₂S-inhibited pigs and minimized in NaHS-treated pigs.

CONCLUSIONS

H₂S elevation in the epileptic brain via activation of CBS contributes to functional hyperemia and exhibits cerebroprotective properties. The H₂S donor NaHS enhances brain antioxidant defense and provides a therapeutic approach for preventing adverse cerebral vascular outcome of neonatal epileptic seizures.

IMPACT

Epileptic seizures in neonates lead to prolonged postictal cerebral vascular dysregulation. The role of hydrogen sulfide (H₂S), a mediator with vasodilator and antioxidant properties, in the epileptic brain has been explored. Astrocytes are major sites of enzymatic H₂S production in the epileptic brain. Postictal cerebral vascular dysfunction is exaggerated when astrocyte H₂S production is pharmacologically inhibited during seizures. Postictal cerebral vascular dysfunction is minimized when the brain H₂S is elevated by systemic administration of NaHS during seizures. NaHS provides a therapeutic approach for improving cerebrovascular outcome of epileptic seizures via a mechanism that involves the antioxidant potential of H₂S.

Regulation of blood pressure by natural sulfur compounds: Focus on their mechanisms of action

Natural sulfur compounds are emerging as therapeutic options for the management of hypertension and prehypertension. They are mainly represented by polysulfides from Alliaceae (i.e., garlic) and isothiocyanates from Brassicaceae (or crucifers). The beneficial cardiovascular effects of these compounds, especially garlic polysulfides, are well known and widely reported both in preclinical and clinical studies. However, only a few authors have linked the ability of natural sulfur compounds to induce vasorelaxation and subsequent antihypertensive effects with their ability to release hydrogen sulfide (H₂S) in biological tissue. H₂S is an endogenous gasotransmitter involved in vascular tone regulation. Some cardiovascular diseases, such as hypertension, are associated with lower plasma H₂S levels. Consequently, exogenous sources of H₂S (H₂S donors) have been designed and synthesized or identified among secondary plant metabolites as potential therapeutic options. In addition to antioxidant effects due to its chemical properties as a reducing agent, H₂S induces vasorelaxation by interacting with a range of molecular targets. The mechanisms of action accounting for H₂S-induced vasodilation include opening of vascular potassium channels (such as ATP-sensitive (K_ATP) and voltage-operated (Kv7) channels), inhibition of 5-phosphodiesterase (5-PDE), and activation of vascular endothelial growth factor receptor-2 (VEGFR-2). These effects may be attributed to H₂S-induced S-persulfidation (or S-sulfhydration), which is a posttranslational modification of cysteine residues of many types of proteins resulting in structural and functional alterations (activation/inhibition). Thus, H₂S donors, such as natural sulfur compounds, are promising antihypertensive agents with novel mechanisms of action.

Hydrogen sulfide poisoning in forensic pathology and toxicology: mechanism and metabolites quantification analysis

Historically, hydrogen sulfide (H₂S) poisoning has extremely high and irreparable mortality. Currently, the identification of H₂S poisoning needs to combine with the case scene analysis in forensic medicine. The anatomy of the deceased seldom had obvious features. There are also a few reports about H₂S poisoning in detail. As a result, we give a comprehensive analysis of the related knowledge on the forensic aspect of H₂S poisoning. Furthermore, we provide the analytical methods of H₂S and its metabolite-which may assist in H₂S poisoning identification.

Hydrogen Sulfide-Induced Vasodilation: The Involvement of Vascular Potassium Channels

Hydrogen sulfide (H₂S) has been highlighted as an important gasotransmitter in mammals. A growing number of studies have indicated that H₂S plays a key role in the pathophysiology of vascular diseases and physiological vascular homeostasis. Alteration in H₂S biogenesis has been reported in a variety of vascular diseases and H₂S supplementation exerts effects of vasodilation. Accumulating evidence has shown vascular potassium channels activation is involved in H₂S-induced vasodilation. This review aimed to summarize and discuss the role of H₂S in the regulation of vascular tone, especially by interaction with different vascular potassium channels and the underlying mechanisms.

Role of hydrogen sulfide in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a common acute and severe disease worldwide, which imposes a heavy burden on families and society. However, the current therapeutic strategies for SAH are unsatisfactory. Hydrogen sulfide (H₂ S), as the third gas signaling molecule after carbon monoxide and nitric oxide, has been widely studied recently. There is growing evidence that H₂ S has a promising future in the treatment of central nervous system diseases. In this review, we focus on the effects of H₂ S in experimental SAH and elucidate the underlying mechanisms. We demonstrate that H₂ S has neuroprotective effects and significantly reduces secondary damage caused by SAH via antioxidant, antiinflammatory, and antiapoptosis mechanisms, and by alleviating cerebral edema and vasospasm. Based on these findings, we believe that H₂ S has great potential in the treatment of SAH and warrants further study to promote its early clinical application.

H2S in Horticultural Plants: Endogenous Detection by an Electrochemical Sensor, Emission by a Gas Detector, and Its Correlation with L-Cysteine Desulfhydrase (LCD) Activity

H2S has acquired great attention in plant research because it has signaling functions under physiological and stress conditions. However, the direct detection of endogenous H2S and its potential emission is still a challenge in higher plants. In order to achieve a comparative analysis of the content of H2S among different plants with agronomical and nutritional interest including pepper fruits, broccoli, ginger, and different members of the genus Allium such as garlic, leek, Welsh and purple onion, the endogenous H2S and its emission was determined using an ion-selective microelectrode and a specific gas detector, respectively. The data show that endogenous H2S content range from pmol to μmol H2S · g-1 fresh weight whereas the H2S emission of fresh-cut vegetables was only detected in the different species of the genus Allium with a maximum of 9 ppm in garlic cloves. Additionally, the activity and isozymes of the L-cysteine desulfhydrase (LCD) were analyzed, which is one of the main enzymatic sources of H2S, where the different species of the genus Allium showed the highest activities. Using non-denaturing gel electrophoresis, the data indicated the presence of up to nine different LCD isozymes from one in ginger to four in onion, leek, and broccoli. In summary, the data indicate a correlation between higher LCD activity with the endogenous H2S content and its emission in the analyzed horticultural species. Furthermore, the high content of endogenous H2S in the Allium species supports the recognized benefits for human health, which are associated with its consumption.

Protein S-sulfhydration: Unraveling the prospective of hydrogen sulfide in the brain, vasculature and neurological manifestations

Hydrogen sulfide (H₂S) and hydrogen polysulfides (H₂S_n) are essential regulatory signaling molecules generated by the entire body, including the central nervous system. Researchers have focused on the classical H₂S signaling from the past several decades, whereas the last decade has shown the emergence of H₂S-induced protein S-sulfhydration signaling as a potential therapeutic approach. Cysteine S-persulfidation is a critical paradigm of post-translational modification in the process of H₂S signaling. Additionally, studies have shown the cross-relationship between S-sulfhydration and other cysteine-induced post-translational modifications, namely nitrosylation and carbonylation. In the central nervous system, S-sulfhydration is involved in the cytoprotection through various signaling pathways, viz. inflammatory response, oxidative stress, endoplasmic reticulum stress, atherosclerosis, thrombosis, and angiogenesis. Further, studies have demonstrated H₂S-induced S-sulfhydration in regulating different biological processes, such as mitochondrial integrity, calcium homeostasis, blood-brain permeability, cerebral blood flow, and long-term potentiation. Thus, protein S-sulfhydration becomes a crucial regulatory molecule in cerebrovascular and neurodegenerative diseases. Herein, we first described the generation of intracellular H₂S followed by the application of H₂S in the regulation of cerebral blood flow and blood-brain permeability. Further, we described the involvement of S-sulfhydration in different biological and cellular functions, such as inflammatory response, mitochondrial integrity, calcium imbalance, and oxidative stress. Moreover, we highlighted the importance of S-sulfhydration in cerebrovascular and neurodegenerative diseases.

Sulforaphane Ameliorates Metabolic Changes Associated With Status Epilepticus in Immature Rats

Status epilepticus (SE) is a common paediatric emergency with the highest incidence in the neonatal period and is a well-known epileptogenic insult. As previously established in various experimental and human studies, SE induces long-term alterations to brain metabolism, alterations that directly contribute to the development of epilepsy. To influence these changes, organic isothiocyanate compound sulforaphane (SFN) has been used in the present study for its known effect of enhancing antioxidative, cytoprotective, and metabolic cellular properties via the Nrf2 pathway. We have explored the effect of SFN in a model of acquired epilepsy induced by Li-Cl pilocarpine in immature rats (12 days old). Energy metabolites PCr, ATP, glucose, glycogen, and lactate were determined by enzymatic fluorimetric methods during the acute phase of SE. Protein expression was evaluated by Western blot (WB) analysis. Neuronal death was scored on the FluoroJadeB stained brain sections harvested 24 h after SE. To assess the effect of SFN on glucose metabolism we have performed a series of 18F-DG μCT/PET recordings 1 h, 1 day, and 3 weeks after the induction of SE. Responses of cerebral blood flow (CBF) to electrical stimulation and their influence by SFN were evaluated by laser Doppler flowmetry (LDF). We have demonstrated that the Nrf2 pathway is upregulated in the CNS of immature rats after SFN treatment. In the animals that had undergone SE, SFN was responsible for lowering glucose uptake in most regions 1 h after the induction of SE. Moreover, SFN partially reversed hypometabolism observed after 24 h and achieved full reversal at approximately 3 weeks after SE. Since no difference in cell death was observed in SFN treated group, these changes cannot be attributed to differences in neurodegeneration. SFN per se did not affect the glucose uptake at any given time point suggesting that SFN improves endogenous CNS ability to adapt to the epileptogenic insult. Furthermore, we had discovered that SFN improves blood flow and accelerates CBF response to electrical stimulation. Our findings suggest that SFN improves metabolic changes induced by SE which have been identified during epileptogenesis in various animal models of acquired epilepsy.

Glucoraphanin Increases Intracellular Hydrogen Sulfide (H2S) Levels and Stimulates Osteogenic Differentiation in Human Mesenchymal Stromal Cell

Osteopenia and osteoporosis are among the most prevalent consequences of ageing, urging the promotion of healthy nutritional habits as a tool in preventing bone fractures. Glucosinolates (GLSs) are organosulfur compounds considered relatively inert precursors of reactive derivatives isothiocyanates (ITCs). Recent evidence suggests that GLSs may exert biological properties based on their capacity to release hydrogen sulfide (H₂S). H₂S-donors are known to exert anabolic function on bone cells. Here, we investigated whether a GLS, glucoraphanin (GRA) obtained from Tuscan black kale, promotes osteogenesis in human mesenchymal stromal cells (hMSCs). H₂S release in buffer and intracellular H₂S levels were detected by amperometric measurements and fluorimetric/cytofluorimetric analyses, respectively. Alizarin red staining assay and real-time PCR were performed to evaluate mineral apposition and mRNA expression of osteogenic genes. Using an in vitro cell culture model, our data demonstrate a sulforaphane (SFN)-independent osteogenic stimulation of GRA in hMSCs, at least partially attributable to H₂S release. In particular, GRA upregulated the expression of osteogenic genes and enhanced mineral apposition while increasing intracellular concentrations of H₂S. Overall, this study suggests the feasibility of using cruciferous derivatives as natural alternatives to chemical H₂S-donors as adjuvant therapies in the treatment of bone-wasting diseases.

Diet and Hydrogen Sulfide Production in Mammals

Significance: In recent times, it has emerged that some dietary sulfur compounds can act on mammalian cell signaling systems via their propensity to release hydrogen sulfide (H₂S). H₂S plays important biochemical and physiological roles in the heart, gastrointestinal tract, brain, kidney, and immune systems of mammals. Reduced levels of H₂S in cells and tissues correlate with a spectrum of pathophysiological conditions, including heart disease, diabetes, obesity, and altered immune function. Recent Advances: In the last decade, researchers have now begun to explore the mechanisms by which dietary-derived sulfur compounds, in addition to cysteine, can act as sources of H₂S. This research has led to the identified several compounds, organic sulfides, isothiocyanates, and inorganic sulfur species including sulfate that can act as potential sources of H₂S in mammalian cells and tissues. Critical Issues: We have summarised progress made in the identification of dietary factors that can impact on endogenous H₂S levels in mammals. We also describe current research focused on how some sulfur molecules present in dietary plants, and associated chemical analogues, act as sources of H₂S, and discuss the biological properties of these molecules as studied in a range of in vitro and in vivo systems. Future Directions: The identification of sulfur compounds in edible plants that can act as novel H₂S releasing molecules is intriguing. Research in this area could inform future studies exploring the impact of diet on H₂S levels in mammalian systems. Despite recent progress, additional work is needed to determine the mechanisms by which H₂S is released from these molecules following ingestions of dietary plants in humans, whether the amounts of H₂S produced is of physiological significance following the metabolism of these compounds in vivo, and if diet could be used to manipulated H₂S levels in humans. Importantly, this will lead to a better understanding of the biological significance of H₂S generated from dietary sources, and this information could be used in the development of plant breeding initiatives to increase the levels of H₂S releasing sulfur compounds in crops, or inform dietary intervention strategies that could be used to alter the levels of H₂S in humans.

Taurine treatment reverses protein malnutrition-induced endothelial dysfunction of the pancreatic vasculature: The role of hydrogen sulfide

BACKGROUND

Protein malnutrition in childhood predisposes individuals to vascular and pancreatic endocrine dysfunction, thus increasing the risk of diabetes and hypertension. Because taurine may reduce cardiometabolic risk, we hypothesized that taurine treatment has a beneficial effect on the pancreatic vasculature during protein restriction.

METHODS AND RESULTS

Weaned mice were fed a normal or a low-protein diet and were treated with or without taurine for 3 months. The lieno-pancreatic artery (LPA) from low-protein diet-treated mice exhibited impaired endothelium-dependent relaxation to acetylcholine that was associated with decreased endothelium-derived hyperpolarization (EDH), hydrogen sulfide (H₂S) production, and H₂S-synthesizing CBS expression and impaired vasorelaxation to an H₂S-donor, NaHS. These changes were prevented by taurine treatment. We compared the effects of taurine with the effects of the direct vasodilator hydralazine and found that both normalized blood pressure and the endothelial vasodilator function of the LPA in the mice fed a protein-restricted diet. However, only taurine restored the CBS expression in the LPA and insulin secretion in response to high glucose. The LPA supplies the pancreas and shares morphometry with the mesenteric resistance artery (MRA). However, in the MRA, low-protein diet-induced endothelial dysfunction is driven by impaired NOS-derived NO with no changes in H₂S signaling.

CONCLUSIONS

The results suggest that taurine protects against protein malnutrition-induced endothelial dysfunction in the LPA by upregulating the CBS-H₂S pathway. Considering the importance of the pancreatic vasculature for endocrine islet activity, taurine may be a potential therapy for the vascular and metabolic dysfunction associated with malnutrition and comorbidities.

The Potential of Hydrogen Sulfide Donors in Treating Cardiovascular Diseases

Hydrogen sulfide (H2S) has long been considered as a toxic gas, but as research progressed, the idea has been updated and it has now been shown to have potent protective effects at reasonable concentrations. H2S is an endogenous gas signaling molecule in mammals and is produced by specific enzymes in different cell types. An increasing number of studies indicate that H2S plays an important role in cardiovascular homeostasis, and in most cases, H2S has been reported to be downregulated in cardiovascular diseases (CVDs). Similarly, in preclinical studies, H2S has been shown to prevent CVDs and improve heart function after heart failure. Recently, many H2S donors have been synthesized and tested in cellular and animal models. Moreover, numerous molecular mechanisms have been proposed to demonstrate the effects of these donors. In this review, we will provide an update on the role of H2S in cardiovascular activities and its involvement in pathological states, with a special focus on the roles of exogenous H2S in cardiac protection.

Sulforaphane Protects Piglet Brains from Neonatal Hypoxic-Ischemic Injury

The striatal, primary sensorimotor cortical, and thalamic neurons are highly vulnerable to hypoxia-ischemia (HI) in term newborns. In a piglet model of HI that exhibits similar selective regional vulnerability, we tested the hypothesis that early treatment with sulforaphane, an activator of the Nrf2 transcription factor, protects vulnerable neurons from HI injury. Anesthetized piglets (aged 3-7 days) were subjected to 45 min of hypoxia and 7 min of airway occlusion. At 15 min after resuscitation, the piglets received intravenous vehicle or sulforaphane. At 4 days of recovery, the density of viable neurons in the putamen of vehicle-treated piglets was 31 ± 34% (±SD) that of sham-operated controls. Treatment with sulforaphane significantly increased viability to 77 ± 31%. In the sensorimotor cortex, neuronal viability was also increased; it was 59 ± 35% in the vehicle-treated and 89 ± 15% in the sulforaphane-treated animals. Treatment with sulforaphane increased the nuclear Nrf2 and γ-glu-tamylcysteine synthetase expression at 6 h of recovery in these regions. We conclude that systemic administration of sulforaphane 15 min after HI can induce the translocation of Nrf2 to the nucleus, increase expression of an enzyme involved in glutathione synthesis, and salvage neurons in the highly vulnerable putamen and sensorimotor cortex in a large-animal model of HI. Therefore, targeting Nrf2 activation soon after recovery from HI is a feasible approach for neuroprotection in the newborn brain.

Pharmacological modulation of the hydrogen sulfide (H2 S) system by dietary H2 S-donors: A novel promising strategy in the prevention and treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents the most common age-related metabolic disorder, and its management is becoming both a health and economic issue worldwide. Moreover, chronic hyperglycemia represents one of the main risk factors for cardiovascular complications. In the last years, the emerging evidence about the role of the endogenous gasotransmitter hydrogen sulfide (H₂ S) in the pathogenesis and progression of T2DM led to increasing interest in the pharmacological modulation of endogenous "H₂ S-system". Indeed, H₂ S directly contributes to the homeostatic maintenance of blood glucose levels; moreover, it improves impaired angiogenesis and endothelial dysfunction under hyperglycemic conditions. Moreover, H₂ S promotes significant antioxidant, anti-inflammatory, and antiapoptotic effects, thus preventing hyperglycemia-induced vascular damage, diabetic nephropathy, and cardiomyopathy. Therefore, H₂ S-releasing molecules represent a promising strategy in both clinical management of T2DM and prevention of macro- and micro-vascular complications associated to hyperglycemia. Recently, growing attention has been focused on dietary organosulfur compounds. Among them, garlic polysulfides and isothiocyanates deriving from Brassicaceae have been recognized as H₂ S-donors of great pharmacological and nutraceutical interest. Therefore, a better understanding of the therapeutic potential of naturally occurring H₂ S-donors may pave the way to a more rational use of these nutraceuticals in the modulation of H₂ S homeostasis in T2DM.

Acute antioxidant and cytoprotective effects of sulforaphane in brain endothelial cells and astrocytes during inflammation and excitotoxicity

Sulforaphane (SFN), a bioactive phytochemical isothiocyanate, has a wide spectrum of cytoprotective effects that involve induction of antioxidant genes. Nongenomic antioxidant effects of SFN have not been investigated. Brain oxidative stress during inflammation and excitotoxicity leads to neurovascular injury. We tested the hypothesis that SNF exhibits acute antioxidant effects and prevents neurovascular injury during oxidative stress. In primary cultures of cerebral microvascular endothelial cells (CMVEC) and cortical astrocytes from the newborn pig brain, a pro-inflammatory cytokine TNF-α and an excitotoxic glutamate elevate reactive oxygen species (ROS) and cause cell death by apoptosis. Nox4 NADPH oxidase is the main Nox isoform in CMVEC and cortical astrocytes that is acutely activated by TNF-α and glutamate leading to ROS-mediated cell death by apoptosis. The Nox4 inhibitor GKT137831 blocked NADPH oxidase activity and overall ROS elevation, and prevented apoptosis of CMVEC and astrocytes exposed to TNF-α and glutamate, supporting the leading role of Nox4 in the neurovascular injury. Synthetic SFN (10-11 -10-6  mol/L) inhibited NADPH oxidase activity and reduced overall ROS production in CMVEC and astrocytes within 1-hour exposure to TNF-α and glutamate. Furthermore, in the presence of SFN, the ability of TNF-α and glutamate to produce apoptosis in CMVEC and cortical astrocytes was completely prevented. Overall, SFN at low concentrations exhibits antioxidant and antiapoptotic effects in cerebral endothelial cells and cortical astrocytes via a via a nongenomic mechanism that involves inhibition of Nox4 NADPH oxidase activity. SFN may prevent cerebrovascular injury during brain oxidative stress caused by inflammation and glutamate excitotoxicity.