Sulforaphane activates the cerebral vascular Nrf2-ARE pathway and suppresses inflammation to attenuate cerebral vasospasm in rat with subarachnoid hemorrhage

A Randomised Controlled Trial of SFX-01 After Subarachnoid Haemorrhage - The SAS Study

SFX-01 is a novel drug for clinical delivery of sulforaphane (SFN). SFN is a potent nuclear factor erythroid 2-related factor 2 activator that reduces inflammation and oxidation, improving outcomes after subarachnoid haemorrhage (SAH) in animal models. This was a multi-centre, double-blind, placebo-controlled, parallel-group randomised clinical trial to evaluate the safety, pharmacokinetics and efficacy of 28 days of SFX-01 300 mg BD in patients aged 18-80 with spontaneous SAH and high blood load on CT. Primary outcomes were (1) safety, (2) plasma and CSF SFN and metabolite levels and (3) vasospasm on transcranial doppler ultrasound. Secondary outcomes included CSF haptoglobin and malondialdehyde and clinical outcome on the modified Rankin Scale (mRS) and SAH outcome tool (SAHOT). A total of 105 patients were randomised (54 SFX-01, 51 placebo). There were no differences in adverse events other than nausea (9 SFX-01 (16.7%), 1 placebo (2.0%)). SFN, SFN-glutathione and SFN-N-acetyl-cysteine AUClast were 16.2, 277 and 415 h × ng/ml. Plasma SFN was higher in GSTT1 null individuals (t = 2.40, p = 0.023). CSF levels were low with many samples below the lower limit of quantification and predicted by the CSF/serum albumin ratio (R2 = 0.182, p = 0.039). There was no difference in CSF haptoglobin (1.981 95%CI 0.992-3.786, p = 0.052) or malondialdehyde (1.12 95%CI 0.7477-1.687, p = 0.572) or middle cerebral artery flow velocity (1.04 95%CI 0.903-1.211, p = 0.545) or functional outcome (mRS 1.647 95%CI 0.721-3.821, p = 0.237, SAHOT 1.082 95%CI 0.464-2.525, p = 0.855). SFX-01 is safe and effective for the delivery of SFN in acutely unwell patients. SFN penetrated CSF less than expected and did not reduce large vessel vasospasm or improve outcome. Trial registration: NCT02614742 clinicaltrials.gov.

Anti-Inflammatory Therapeutic Mechanisms of Isothiocyanates: Insights from Sulforaphane

Isothiocyanates (ITCs) belong to a group of natural products that possess a highly reactive electrophilic -N=C=S functional group. They are stored in plants as precursor molecules, glucosinolates, which are processed by the tyrosinase enzyme upon plant tissue damage to release ITCs, along with other products. Isolated from broccoli, sulforaphane is by far the most studied antioxidant ITC, acting primarily through the induction of a transcription factor, the nuclear factor erythroid 2-related factor 2 (Nrf2), which upregulates downstream antioxidant genes/proteins. Paradoxically, sulforaphane, as a pro-oxidant compound, can also increase the levels of reactive oxygen species, a mechanism which is attributed to its anticancer effect. Beyond highlighting the common pro-oxidant and antioxidant effects of sulforaphane, the present paper was designed to assess the diverse anti-inflammatory mechanisms reported to date using a variety of in vitro and in vivo experimental models. Sulforaphane downregulates the expression of pro-inflammatory cytokines, chemokines, adhesion molecules, cycloxyhenase-2, and inducible nitric oxide synthase. The signalling pathways of nuclear factor κB, activator protein 1, sirtuins 1, silent information regulator sirtuin 1 and 3, and microRNAs are among those affected by sulforaphane. These anti-inflammatory actions are sometimes due to direct action via interaction with the sulfhydryl structural moiety of cysteine residues in enzymes/proteins. The following are among the topics discussed in this paper: paradoxical signalling pathways such as the immunosuppressant or immunostimulant mechanisms; crosstalk between the oxidative and inflammatory pathways; and effects dependent on health and disease states.

Red Blood Cells in the Cerebrospinal Fluid Compartment After Subarachnoid Haemorrhage: Significance and Emerging Therapeutic Strategies

Subarachnoid haemorrhage (SAH) is a subtype of stroke that predominantly impacts younger individuals. It is associated with high mortality rates and can cause long-term disabilities. This review examines the contribution of the initial blood load and the dynamics of clot clearance to the pathophysiology of SAH and the risk of adverse outcomes. These outcomes include hydrocephalus and delayed cerebral ischaemia (DCI), with a particular focus on the impact of blood located in the cisternal spaces, as opposed to ventricular blood, in the development of DCI. The literature described underscores the prognostic value of haematoma characteristics, such as volume, density, and anatomical location. The limitations of traditional radiographic grading systems are discussed, compared with the more accurate volumetric quantification techniques for predicting patient prognosis. Further, the significance of red blood cells (RBCs) and their breakdown products in secondary brain injury after SAH is explored. The review presents novel interventions designed to accelerate clot clearance or mitigate the effects of toxic byproducts released from erythrolysis in the cerebrospinal fluid following SAH. In conclusion, this review offers deeper insights into the complex dynamics of SAH and discusses the potential pathways available for advancing its management.

Sulforaphane's Multifaceted Potential: From Neuroprotection to Anticancer Action

Sulforaphane (SFN) is a naturally occurring compound found in cruciferous vegetables such as broccoli and cauliflower. It has been widely studied for its potential as a neuroprotective and anticancer agent. This review aims to critically evaluate the current evidence supporting the neuroprotective and anticancer effects of SFN and the potential mechanisms through which it exerts these effects. SFN has been shown to exert neuroprotective effects through the activation of the Nrf2 pathway, the modulation of neuroinflammation, and epigenetic mechanisms. In cancer treatment, SFN has demonstrated the ability to selectively induce cell death in cancer cells, inhibit histone deacetylase, and sensitize cancer cells to chemotherapy. SFN has also shown chemoprotective properties through inhibiting phase I metabolizing enzymes, modulating phase II xenobiotic-metabolizing enzymes, and targeting cancer stem cells. In addition to its potential as a therapeutic agent for neurological disorders and cancer treatment, SFN has shown promise as a potential treatment for cerebral ischemic injury and intracranial hemorrhage. Finally, the ongoing and completed clinical trials on SFN suggest potential therapeutic benefits, but more research is needed to establish its effectiveness. Overall, SFN holds significant promise as a natural compound with diverse therapeutic applications.

Pharmacological Modulations of Nrf2 and Therapeutic Implications in Aneurysmal Subarachnoid Hemorrhage

An aneurysmal subarachnoid hemorrhage (aSAH) is a subtype of stroke with high morbidity and mortality. The main causes of a poor prognosis include early brain injury (EBI) and delayed vasospasm, both of which play a significant role in the pathophysiological process. As an important mechanism of EBI and delayed vasospasm, oxidative stress plays an important role in the pathogenesis of aSAH by producing reactive oxygen species (ROS) through the mitochondria, hemoglobin, or enzymatic pathways in the early stages of aSAH. As a result, antioxidant therapy, which primarily targets the Nrf2-related pathway, can be employed as a potential strategy for treating aSAH. In the early stages of aSAH development, increasing the expression of antioxidant enzymes and detoxifying enzymes can relieve oxidative stress, reduce brain damage, and improve prognosis. Herein, the regulatory mechanisms of Nrf2 and related pharmacological compounds are reviewed, and Nrf2-targeted drugs are proposed as potential treatments for aSAH.

Genetic variation in NFE2L2 is associated with outcome following aneurysmal subarachnoid haemorrhage

BACKGROUND AND PURPOSE

Nuclear factor erythroid 2-related factor 2 (NRF2; encoded by the NFE2L2 gene) has been implicated in outcome following aneurysmal subarachnoid haemorrhage (aSAH) through its activity as a regulator of inflammation, oxidative injury and blood breakdown product clearance. The aim of this study was to identify whether genetic variation in NFE2L2 is associated with clinical outcome following aSAH.

METHODS

Ten tagging single nucleotide polymorphisms (SNPs) in NFE2L2 were genotyped and tested for association with dichotomized clinical outcome, assessed by the modified Rankin scale, in both a discovery and a validation cohort. In silico functional analysis was performed using a range of bioinformatic tools.

RESULTS

One SNP, rs10183914, was significantly associated with outcome following aSAH in both the discovery (n = 1007) and validation cohorts (n = 466). The risk of poor outcome was estimated to be 1.33-fold (95% confidence interval 1.12-1.58) higher in individuals with the T allele of rs10183914 (p_{meta-analysis}  = 0.001). In silico functional analysis identified rs10183914 as a potentially regulatory variant with effects on transcription factor binding in addition to alternative splicing with the T allele, associated with a significant reduction in the NFE2L2 intron excision ratio (p_sQTL  = 1.3 × 10^-7 ).

CONCLUSIONS

The NFE2L2 SNP, rs10183914, is significantly associated with outcome following aSAH. This is consistent with a clinically relevant pathophysiological role for oxidative and inflammatory brain injury due to blood and its breakdown products in aSAH. Furthermore, our findings support NRF2 as a potential therapeutic target following aSAH and other forms of intracranial haemorrhage.

Molecular mechanisms of neuronal death in brain injury after subarachnoid hemorrhage

Subarachnoid haemorrhage (SAH) is a common cerebrovascular disease with high disability and mortality rates worldwide. The pathophysiological mechanisms involved in an aneurysm rupture in SAH are complex and can be divided into early brain injury and delayed brain injury. The initial mechanical insult results in brain tissue and vascular disruption with hemorrhages and neuronal necrosis. Following this, the secondary injury results in diffused cerebral damage in the peri-core area. However, the molecular mechanisms of neuronal death following an aneurysmal SAH are complex and currently unclear. Furthermore, multiple cell death pathways are stimulated during the pathogenesis of brain damage. Notably, particular attention should be devoted to necrosis, apoptosis, autophagy, necroptosis, pyroptosis and ferroptosis. Thus, this review discussed the mechanism of neuronal death and its influence on brain injury after SAH.

Inflammation and Oxidative Stress: Potential Targets for Improving Prognosis After Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) has a high mortality rate and causes long-term disability in many patients, often associated with cognitive impairment. However, the pathogenesis of delayed brain dysfunction after SAH is not fully understood. A growing body of evidence suggests that neuroinflammation and oxidative stress play a negative role in neurofunctional deficits. Red blood cells and hemoglobin, immune cells, proinflammatory cytokines, and peroxidases are directly or indirectly involved in the regulation of neuroinflammation and oxidative stress in the central nervous system after SAH. This review explores the role of various cellular and acellular components in secondary inflammation and oxidative stress after SAH, and aims to provide new ideas for clinical treatment to improve the prognosis of SAH.

Adverse Effects of Oxidative Stress on Bone and Vasculature in Corticosteroid-Associated Osteonecrosis: Potential Role of Nuclear Factor Erythroid 2-Related Factor 2 in Cytoprotection

Significance: Osteonecrosis (ON) is characterized by bone tissue death due to disturbance of the nutrient artery. The detailed process leading to the necrotic changes has not been fully elucidated. Clinically, high-dose corticosteroid therapy is one of the main culprits behind osteonecrosis of the femoral head (ONFH). Recent Advances: Numerous studies have proposed that such ischemia concerns various intravascular mechanisms. Of all reported risk factors, the involvement of oxidative stress in the irreversible damage suffered by bone-related and vascular endothelial cells during ischemia simply cannot be overlooked. Several articles also have sought to elucidate oxidative stress in relation to ON using animal models or in vitro cell cultures. Critical Issues: However, as far as we know, antioxidant monotherapy has still not succeeded in preventing ONFH in humans. To provide this desideratum, we herein summarize the current knowledge about the influence of oxidative stress on ON, together with data about the preventive effects of administering antioxidants in corticosteroid-induced ON animal models. Moreover, oxidative stress is counteracted by nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent cytoprotective network through regulating antioxidant expressions. Therefore, we also describe Nrf2 regulation and highlight its role in the pathology of ON. Future Directions: This is a review of all available literature to date aimed at developing a deeper understanding of the pathological mechanism behind ON from the perspective of oxidative stress. It may be hoped that this synthesis will spark the development of a prophylactic strategy to benefit corticosteroid-associated ONFH patients. Antioxid. Redox Signal. 35, 357-376.

Preconditioning Exercise in Rats Attenuates Early Brain Injury Resulting from Subarachnoid Hemorrhage by Reducing Oxidative Stress, Inflammation, and Neuronal Apoptosis

Subarachnoid hemorrhage (SAH) is a catastrophic form of stroke responsible for significant morbidity and mortality. Oxidative stress, inflammation, and neuronal apoptosis are important in the pathogenesis of early brain injury (EBI) following SAH. Preconditioning exercise confers neuroprotective effects, mitigating EBI; however, the basis for such protection is unknown. We investigated the effects of preconditioning exercise on brain damage and sensorimotor function after SAH. Male rats were assigned to either a sham-operated (Sham) group, exercise (Ex) group, or no-exercise (No-Ex) group. After a 3-week exercise program, they underwent SAH by endovascular perforation. Consciousness level, neurological score, and sensorimotor function were studied. The expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), 4-hydroxynonenal (4HNE), nitrotyrosine (NT), ionized calcium-binding adaptor molecule 1 (Iba1), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1β (IL-1β), 14-3-3γ, p-β-catenin Ser37, Bax, and caspase-3 were evaluated by immunohistochemistry or western blotting. The terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling (TUNEL) assay was also performed. After SAH, the Ex group had significantly reduced neurological deficits, sensorimotor dysfunction, and consciousness disorder compared with the No-Ex group. Nrf2, HO-1, and 14-3-3γ were significantly higher in the Ex group, while 4HNE, NT, Iba1, TNF-α, IL-6, IL-1β, Bax, caspase-3, and TUNEL-positive cells were significantly lower. Our findings suggest that preconditioning exercise ameliorates EBI after SAH. The expression of 4HNE and NT was reduced by Nrf2/HO-1 pathway activation; additionally, both oxidative stress and inflammation were reduced. Furthermore, preconditioning exercise reduced apoptosis, likely via the 14-3-3γ/p-β-catenin Ser37/Bax/caspase-3 pathway.

Cruciferous vegetables: rationale for exploring potential salutary effects of sulforaphane-rich foods in patients with chronic kidney disease

Sulforaphane (SFN) is a sulfur-containing isothiocyanate found in cruciferous vegetables (Brassicaceae) and a well-known activator of nuclear factor-erythroid 2-related factor 2 (Nrf2), considered a master regulator of cellular antioxidant responses. Patients with chronic diseases, such as diabetes, cardiovascular disease, cancer, and chronic kidney disease (CKD) present with high levels of oxidative stress and a massive inflammatory burden associated with diminished Nrf2 and elevated nuclear transcription factor-κB-κB expression. Because it is a common constituent of dietary vegetables, the salutogenic properties of sulforaphane, especially it’s antioxidative and anti-inflammatory properties, have been explored as a nutritional intervention in a range of diseases of ageing, though data on CKD remain scarce. In this brief review, the effects of SFN as a senotherapeutic agent are described and a rationale is provided for studies that aim to explore the potential benefits of SFN-rich foods in patients with CKD.

Discovery of Sulforaphane as a Potent BACE1 Inhibitor Based on Kinetics and Computational Studies

BACE1 is the rate-limiting enzyme involved in the production and deposition of β-amyloid (Aβ). Since neurotoxic Aβ plays a critical role in Alzheimer’s disease (AD) pathogenesis, BACE1 has emerged as a key target for preventing AD. In the present study, the potential of sulforaphane, an isothiocyanate found in cruciferous vegetables, as a BACE1 inhibitor has been investigated. Sulforaphane exhibited six times more potent activity against BACE1 compared to well-known positive controls including resveratrol and quercetin. Sulforaphane presented selective and non-competitive BACE1 inhibitory activity with low off-target inhibition of BACE2 and other aspartic and serine proteases. In addition, sulforaphane presented negative binding energy, suggesting that the compound had a high affinity for BACE1. It interacted with locations other than the active binding sites of BACE1 through van der Waals forces. Overall, sulforaphane appeared to be a promising candidate with potent and selective BACE1 inhibitory properties that play an important role in AD prevention.

Sulforaphane mitigates LPS-induced neuroinflammation through modulation of Cezanne/NF-κB signalling

AIM

Neuroinflammation is a potent pathological process of various neurodegenerative diseases. Sulforaphane (SFN) is a natural product and acts as a neuroprotective agent to suppress inflammatory response in brain. The present study investigated the protective effect of Sulforaphane (SFN) on lipopolysaccharide (LPS)-induced neuroinflammation.

MATERIALS AND METHODS

Rats were divided into three groups: control group, LPS group and LPS + SFN group. Morris water maze test was carried out to evaluate the spatial memory and learning function of rats. The inflammatory cytokines levels in hippocampal tissues, plasma were measured by ELISA. The western blot was used to detect Cezanne/NF-κB signalling. For in vitro study, the Cezanne siRNA and scrambled control were transfected into BV2 cells, and then treated with or without 20 μM SFN before exposed to LPS. The inflammatory cytokines levels and Cezanne/NF-κB signalling were detected by ELISA and western blot, respectively. Co-IP assay were applied to investigate the regulation of Cezanne on ubiquitination of TRAF6 and RIP1.

KEY FINDINGS

SFN improved LPS-induced neurocognitive dysfunction in rats. It inhibited the neuroinflammation and activation of NF-κB pathway induced by LPS. The modulation of TRAF6 and RIP1 ubiquitination by Cezanne was playing a pivotal role in relation to the mechanism of SFN inhibiting NF-κB pathway.

SIGNIFICANCE

The results of our study demonstrated that SFN could attenuate LPS-induced neuroinflammation through the modulation of Cezanne/NF-κB signalling.

Sulforaphane improves vascular reactivity in mouse and human arteries after "preeclamptic-like" injury

INTRODUCTION

The widespread maternal endothelial dysfunction that underlies the manifestations of preeclampsia is thought to arise from excessive placental production of antiangiogenic factors and enhanced oxidative stress. Therefore, we assessed whether the natural antioxidant sulforaphane could improve vascular function.

METHODS

Cell viability of human umbilical vein endothelial cells (HUVECs) was assessed after 24 or 48 h in normoxia (20% O₂) or hypoxia (1% O₂) with or without sulforaphane. To model vascular dysfunction associated with preeclampsia, mouse mesenteric arteries were incubated in trophoblast conditioned media (TCM), and human omental arteries incubated in preeclamptic explant media (PEM) with or without sulforaphane. Both media are rich in antiangiogenic compounds associated with preeclampsia. TCM was generated from primary cytotrophoblast cells from term placentae of normotensive, while PEM was generated from explants from preeclamptic women. Reactivity was assessed by wire myography. sulforaphane's actions as a vasodilator were also investigated.

RESULTS

Under conditions of hypoxia, sulforaphane improved HUVEC viability. In mouse mesenteric arteries, sulforaphane reduced contraction evoked by potassium (p < 0.001), phenylephrine and endothelin 1 (all p < 0.001). Sulforaphane also inhibited Ca²⁺-induced contraction (p = 0.014). Sulforaphane prevented TCM-induced augmentation of phenylephrine and angiotensin II-mediated contraction of mouse mesenteric arteries. In human omental arteries, sulforaphane induced vasodilation (p < 0.001), and prevented PEM-induced endothelial dysfunction by restoring arterial sensitivity to the endothelium-dependent vasodilator bradykinin (p = 0.008).

DISCUSSION

Sulforaphane causes relaxation in arteries and protects against arterial dysfunction induced by placental-derived antiangiogenic factors, which are known to contribute to the preeclampsia.

Role of Nrf2 and Its Activators in Cardiocerebral Vascular Disease

Cardiocerebral vascular disease (CCVD) is a common disease with high morbidity, disability, and mortality. Oxidative stress (OS) is closely related to the progression of CCVD. Abnormal redox regulation leads to OS and overproduction of reactive oxygen species (ROS), which can cause biomolecular and cellular damage. The Nrf2/antioxidant response element (ARE) signaling pathway is one of the most important defense systems against exogenous and endogenous OS injury, and Nrf2 is regarded as a vital pharmacological target. The complexity of the CCVD pathological process and the current difficulties in conducting clinical trials have hindered the development of therapeutic drugs. Furthermore, little is known about the role of the Nrf2/ARE signaling pathway in CCVD. Clarifying the role of the Nrf2/ARE signaling pathway in CCVD can provide new ideas for drug design. This review details the recent advancements in the regulation of the Nrf2/ARE system and its role and activators in common CCVD development.

Traumatic Brain Injury and Blood-Brain Barrier (BBB): Underlying Pathophysiological Mechanisms and the Influence of Cigarette Smoking as a Premorbid Condition

Traumatic brain injury (TBI) is among the most pressing global health issues and prevalent causes of cerebrovascular and neurological disorders all over the world. In addition to the brain injury, TBI may also alter the systemic immune response. Thus, TBI patients become vulnerable to infections, have worse neurological outcomes, and exhibit a higher rate of mortality and morbidity. It is well established that brain injury leads to impairments of the blood-brain barrier (BBB) integrity and function, contributing to the loss of neural tissue and affecting the response to neuroprotective drugs. Thus, stabilization/protection of the BBB after TBI could be a promising strategy to limit neuronal inflammation, secondary brain damage, and acute neurodegeneration. Herein, we present a review highlighting the significant post-traumatic effects of TBI on the cerebrovascular system. These include the loss of BBB integrity and selective permeability, impact on BBB transport mechanisms, post-traumatic cerebral edema formation, and significant pathophysiological factors that may further exacerbate post-traumatic BBB dysfunctions. Furthermore, we discuss the post-traumatic impacts of chronic smoking, which has been recently shown to act as a premorbid condition that impairs post-TBI recovery. Indeed, understanding the underlying molecular mechanisms associated with TBI damage is essential to better understand the pathogenesis and progression of post-traumatic secondary brain injury and the development of targeted treatments to improve outcomes and speed up the recovery process. Therapies aimed at restoring/protecting the BBB may reduce the post-traumatic burden of TBI by minimizing the impairment of brain homeostasis and help to restore an optimal microenvironment to support neuronal repair.

Study protocol for SFX-01 after subarachnoid haemorrhage (SAS): a multicentre randomised double-blinded, placebo controlled trial

INTRODUCTION

Subarachnoid haemorrhage (SAH) from a ruptured cerebral aneurysm carries high morbidity and mortality. Despite huge advances in techniques to secure the aneurysm, there has been little progress in the treatment of the deleterious effects of the haemorrhage.Sulforaphane is an Nrf2 inducer with anti-oxidant and anti-inflammatory properties. It has been shown to improve clinical outcome in experimental models of SAH, but is unstable. SFX-01 (Evgen Pharma) is a novel composition comprised of synthetic sulforaphane stabilised within an α-cyclodextrin complex. On ingestion, the complex releases sulforaphane making SFX-01 an ideal vehicle for delivery of sulforaphane.

METHODS AND ANALYSIS

The objective of the study is to assess the safety, pharmacokinetics and efficacy of SFX-01. This is a prospective, multicentre, randomised, double-blind placebo-controlled trial in patients aged 18-80 years with aneurysmal subarachnoid haemorrhage in the previous 48 hours. 90 patients will be randomised to receive SFX-01 (300 mg) or placebo two times per day for up to 28 days.Safety will be assessed using blood tests and adverse event reporting.Pharmacokinetics will be assessed based on paired blood and cerebrospinal fluid (CSF) sulforaphane levels on day 7. A subgroup will have hourly samples taken during 6 hours post-dosing on days 1 and 7. Pharmacodynamics will be assessed by haptoglobin and malondialdehyde levels, and maximum flow velocity of middle cerebral artery will be measured by transcranial Doppler ultrasound.Clinical outcomes will be assessed at days 28, 90 and 180 with modified Rankin Scale, Glasgow Outcome Score, SAH Outcome Tool, Short Form-36, Brain Injury Community Rehabilitation Outcome Scales and Check List for Cognitive and Emotional consequences following stroke. MRI at 6 months including quantitative susceptibility mapping and volumetric T1 will measure iron deposition and cortical volume.Safety, CSF sulforaphane concentration and middle cerebral artery flow velocity will be primary outcomes and all others secondary.

ETHICS AND DISSEMINATION

Ethical approval was obtained from South Central Hampshire A committee. Outcomes of the trial will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02614742.

Emerging promise of sulforaphane-mediated Nrf2 signaling cascade against neurological disorders

Neurological disorders represent a great challenge and are the leading cause of death and disability globally. Although numerous complicated mechanisms are involved in the progressions of chronic and acute neurodegenerative disorders, most of the diseases share mutual pathogenic features such as oxidative stress, mitochondrial dysfunction, neuroinflammation, protein misfolding, excitotoxicity, and neuronal damage, all of these are the common targets of nuclear factor erythroid 2 related factor 2 (Nrf2) signaling cascade. No cure has yet been discovered to tackle these disorders, so, intervention approaches targeting phytochemicals have been recommended as an alternative form of treatment. Sulforaphane is a sulfur-rich dietary phytochemical which has several activities such as antioxidant, anti-inflammatory, and anti-tumor via multiple targets and various mechanisms. Given its numerous actions, sulforaphane has drawn considerable attention for neurological disorders in recent years. Nrf2 is one of the most crucial targets of sulforaphane which has potential in regulating the series of cytoprotective enzyme expressions that have neuroprotective, antioxidative, and detoxification actions. Neurological disorders are auspicious candidates for Nrf2-targeted treatment strategy. Sulforaphane protects various neurological disorders by regulating the Nrf2 pathway. In this article, we recapitulate current studies of sulforaphane-mediated Nrf2 activation in the treatment of various neurological disorders.

Organic Isothiocyanates as Hydrogen Sulfide Donors

Significance: Hydrogen sulfide (H₂S), the "new entry" in the series of endogenous gasotransmitters, plays a fundamental role in regulating the biological functions of various organs and systems. Consequently, the lack of adequate levels of H₂S may represent the etiopathogenetic factor of multiple pathological alterations. In these diseases, the use of H₂S donors represents a precious and innovative opportunity. Recent Advances: Natural isothiocyanates (ITCs), sulfur compounds typical of some botanical species, have long been investigated because of their intriguing pharmacological profile. Recently, the ITC moiety has been proposed as a new H₂S-donor chemotype (with a l-cysteine-mediated reaction). Based on this recent discovery, we can clearly observe that almost all the effects of natural ITCs can be explained by the H₂S release. Consistently, the ITC function was also used as an original H₂S-releasing moiety for the design of synthetic H₂S donors and original "pharmacological hybrids." Very recently, the chemical mechanism of H₂S release, resulting from the reaction between l-cysteine and some ITCs, has been elucidated. Critical Issues: Available literature gives convincing demonstration that H₂S is the real player in ITC pharmacology. Further, countless studies have been carried out on natural ITCs, but this versatile moiety has been used only rarely for the design of synthetic H₂S donors with optimal drug-like properties. Future Directions: The development of more ITC-based synthetic H₂S donors with optimal drug-like properties and selectivity toward specific tissues/pathologies seem to represent a stimulating and indispensable prospect of future experimental activities.

Nuclear factor erythroid 2 - related factor 2 and its relationship with cellular response in nickel exposure: a systems biology analysis

Background

Nickel and nickel-containing compounds (NCC) are known human carcinogens. However, the precise molecular mechanisms of nickel-induced malignant transformation remain unknown. Proposed mechanisms suggest that nickel and NCC may participate in the dual activation/inactivation of enzymatic pathways involved in cell defenses against oxidative damage, where Nuclear factor-erythroid 2 related factor 2 (Nrf2) plays a central role.

Methods

For assessing the potential role of proteins involved in the Nrf2-mediated response to nickel and NCC exposure, we designed an interactome network using the STITCH search engine version 5.0 and the STRING software 10.0. The major NCC-protein interactome (NCPI) generated was analyzed using the MCODE plugin, version 1.5.1 for the detection of interaction modules or subnetworks. Main centralities of the NCPI were determined with the CentiScape 2.2 plugin of Cytoscape 3.4.0 and main biological processes associated with each cluster were assessed using the BiNGO plugin of Cytoscape 3.4.0.

Results

Water-soluble NiSO₄ and insoluble Ni₃S₂ were the most connected to proteins involved in the NCPI network. Nfr2 was detected as one of the most relevant proteins in the network, participating in several multifunctional protein complexes in clusters 1, 2, 3 and 5. Ontological analysis of cluster 3 revealed several processes related to unfolded protein response (UPR) and response to endoplasmic reticulum (ER) stress.

Conclusions

Cellular response to NCC exposure was very comparable, particularly concerning oxidative stress response, inflammation, cell cycle/proliferation, and apoptosis. In this cellular response, Nfr2 was highly centralized and participated in several multifunctional protein complexes, including several related to ER-stress. These results add evidence on the possible Ni²⁺ induced – ER stress mainly associated with insoluble NCC. In this scenario, we also show how protein degradation mediated by ubiquitination seems to play key roles in cellular responses to Ni.

Haemoglobin scavenging in intracranial bleeding: biology and clinical implications

Haemoglobin is released into the CNS during the breakdown of red blood cells after intracranial bleeding. Extracellular free haemoglobin is directly neurotoxic. Haemoglobin scavenging mechanisms clear haemoglobin and reduce toxicity; these mechanisms include erythrophagocytosis, haptoglobin binding of haemoglobin, haemopexin binding of haem and haem oxygenase breakdown of haem. However, the capacity of these mechanisms is limited in the CNS, and they easily become overwhelmed. Targeting of haemoglobin toxicity and scavenging is, therefore, a rational therapeutic strategy. In this Review, we summarize the neurotoxic mechanisms of extracellular haemoglobin and the peculiarities of haemoglobin scavenging pathways in the brain. Evidence for a role of haemoglobin toxicity in neurological disorders is discussed, with a focus on subarachnoid haemorrhage and intracerebral haemorrhage, and emerging treatment strategies based on the molecular pathways involved are considered. By focusing on a fundamental biological commonality between diverse neurological conditions, we aim to encourage the application of knowledge of haemoglobin toxicity and scavenging across various conditions. We also hope that the principles highlighted will stimulate research to explore the potential of the pathways discussed. Finally, we present a consensus opinion on the research priorities that will help to bring about clinical benefits.

Cerebrovascular and Neurological Disorders: Protective Role of NRF2

Cellular defense mechanisms, intracellular signaling, and physiological functions are regulated by electrophiles and reactive oxygen species (ROS). Recent works strongly considered imbalanced ROS and electrophile overabundance as the leading cause of cellular and tissue damage, whereas oxidative stress (OS) plays a crucial role for the onset and progression of major cerebrovascular and neurodegenerative pathologies. These include Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD), stroke, and aging. Nuclear factor erythroid 2-related factor (NRF2) is the major modulator of the xenobiotic-activated receptor (XAR) and is accountable for activating the antioxidative response elements (ARE)-pathway modulating the detoxification and antioxidative responses of the cells. NRF2 activity, however, is also implicated in carcinogenesis protection, stem cells regulation, anti-inflammation, anti-aging, and so forth. Herein, we briefly describe the NRF2–ARE pathway and provide a review analysis of its functioning and system integration as well as its role in major CNS disorders. We also discuss NRF2-based therapeutic approaches for the treatment of neurodegenerative and cerebrovascular disorders.

Neuroprotective Role of the Nrf2 Pathway in Subarachnoid Haemorrhage and Its Therapeutic Potential

The mechanisms underlying poor outcome following subarachnoid haemorrhage (SAH) are complex and multifactorial. They include early brain injury, spreading depolarisation, inflammation, oxidative stress, macroscopic cerebral vasospasm, and microcirculatory disturbances. Nrf2 is a global promoter of the antioxidant and anti-inflammatory response and has potential protective effects against all of these mechanisms. It has been shown to be upregulated after SAH, and Nrf2 knockout animals have poorer functional and behavioural outcomes after SAH. There are many agents known to activate the Nrf2 pathway. Of these, the actions of sulforaphane, curcumin, astaxanthin, lycopene, tert-butylhydroquinone, dimethyl fumarate, melatonin, and erythropoietin have been studied in SAH models. This review details the different mechanisms of injury after SAH including the contribution of haemoglobin (Hb) and its breakdown products. It then summarises the evidence that the Nrf2 pathway is active and protective after SAH and finally examines the evidence supporting Nrf2 upregulation as a therapy after SAH.

Effects of sulforaphane in the central nervous system

Sulforaphane (SFN) is an active component extracted from vegetables like cauliflower and broccoli. Activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling is a common mechanism for the anti-oxidative and anti-inflammatory activity of some herb-derived compounds, such as icariin and berberine. However, due to its peculiar ability in Nrf2 activation, SFN is recognized as an activator of Nrf2 and recommended as a supplementation for prevention and/or treatment of disorders like neoplasm and heart failure. In the central nervous system (CNS), the prophylactic and/or therapeutic effects of SFN have been revealed in recent years. For example, it has been reported to prevent the progression of Alzheimer's disease, Parkinson's disease, cerebral ischemia, Huntington's disease, multiple sclerosis, epilepsy, and psychiatric disorders via promotion of neurogenesis or inhibition of oxidative stress and neuroinflammation. SFN is also implicated in reversing cognition, learning, and memory impairment in rodents induced by scopolamine, lipopolysaccharide, okadaic acid, and diabetes. In models of neurotoxicity, SFN has been shown to suppress neurotoxicity induced by a wide range of toxic factors, such as hydrogen peroxide, prion protein, hyperammonemia, and methamphetamine. To date, no consolidated source of knowledge about the pharmacological effects of SFN in the CNS has been presented in the literature. In this review, we summarize and discuss the pharmacological effects of SFN as well as their possible mechanisms in prevention and/or therapy of disorders afflicting the CNS, aiming to get a further insight into how SFN affects the pathophysiological process of CNS disorders.

NRF2 and NF-қB interplay in cerebrovascular and neurodegenerative disorders: Molecular mechanisms and possible therapeutic approaches

Electrophiles and reactive oxygen species (ROS) play a major role in modulating cellular defense mechanisms as well as physiological functions, and intracellular signaling. However, excessive ROS generation (endogenous and exogenous) can create a state of redox imbalance leading to cellular and tissue damage (Ma and He, 2012) [1]. A growing body of research data strongly suggests that imbalanced ROS and electrophile overproduction are among the major prodromal factors in the onset and progression of several cerebrovascular and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and aging (Ma and He, 2012; Ramsey et al., 2017; Salminen et al., 2012; Sandberg et al., 2014; Sarlette et al., 2008; Tanji et al., 2013) [1-6]. Cells offset oxidative stress by the action of housekeeping antioxidative enzymes (such as superoxide dismutase, catalase, glutathione peroxidase) as well direct and indirect antioxidants (Dinkova-Kostova and Talalay, 2010) [7]. The DNA sequence responsible for modulating the antioxidative and cytoprotective responses of the cells has been identified as the antioxidant response element (ARE), while the nuclear factor erythroid 2-related factor (NRF2) is the major regulator of the xenobiotic-activated receptor (XAR) responsible for activating the ARE-pathway, thus defined as the NRF2-ARE system (Ma and He, 2012) [1]. In addition, the interplay between the NRF2-ARE system and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB, a protein complex that controls cytokine production and cell survival), has been further investigated in relation to neurodegenerative and neuroinflammatory disorders. On these premises, we provide a review analysis of current understanding of the NRF2-NF-ĸB interplay, their specific role in major CNS disorders, and consequent therapeutic implication for the treatment of neurodegenerative and cerebrovascular diseases.

Salvinorin A ameliorates cerebral vasospasm through activation of endothelial nitric oxide synthase in a rat model of subarachnoid hemorrhage

OBJECTIVE

This study aimed to demonstrate the potential of salvinorin A (SA) for cerebral vasospasm after subarachnoid hemorrhage (SAH) and investigate mechanisms of therapeutic effect using rat SAH model.

METHODS

Salvinorin A was injected intraperitoneally, and the neurobehavioral changes were observed at 12 hours, 24 hours, 48 hours, and 72 hours after SAH. Basilar artery was observed by magnetic resonance imaging (MRI). The inner diameter and thickness of basilar artery were measured. The morphological changes and the apoptosis in CA1 area of hippocampus were detected. Endothelin-1 (ET-1) and nitric oxide (NO) levels were detected by ELISA kit. The protein expression of endothelial NO synthase (eNOS) and aquaporin-4 (AQP-4) was determined by Western blot for potential mechanism exploration.

RESULTS

Salvinorin A administration could relieve neurological deficits, decrease the neuronal apoptosis, and alleviate the morphological changes in CA1 area of hippocampus. SA alleviated CVS by increasing diameter and decreasing thickness of basilar artery, and such changes were accompanied by the decreased concentration of ET-1 and increased level of NO. Meanwhile, SA increased the expression of eNOS and decreased the expression of AQP-4 protein in the basilar artery and hippocampus.

CONCLUSIONS

Salvinorin A attenuated CVS and alleviated brain injury after SAH via increasing expression of eNOS and NO content, and decreasing ET-1 concentration and AQP-4 protein expression.

Crucifers and related vegetables and supplements for neurologic disorders: what is the evidence?

PURPOSE OF REVIEW

Neurologic disorders have varied pathophysiology, yet many of them appear to have core molecular pathways that are aberrant. We review the evidence that a dietary component may have utility in ameliorating or preventing at least some of them.

RECENT FINDINGS

The weight of evidence supporting prescriptive dietary recommendations to promote or enhance healthspan has been building for decades. Cruciferous vegetables are a key part of the arsenal of nutrition-based approaches for reducing the burden of chronic disease. Much new evidence suggests that neurological disorders are among the potential targets for this approach. This evidence includes at least nine clinical studies of neurodevelopmental conditions like autism spectrum disorder and schizophrenia, and there are a great many studies in animal model systems, of neurodegenerative disorders like Alzheimer's and Parkinson's diseases. This review highlights the most bioactive and most well-studied compounds from crucifers - the isothiocyanates, in particular sulforaphane.

SUMMARY

There is great promise for the regular use of cruciferous vegetables or supplements containing standardized levels of bioactives in the treatment and prevention of neurologic disorders. Many clinical and animal studies are underway, and the evidence is building to support this strategy.

New highlights on the health-improving effects of sulforaphane

In this paper, we review recent evidence about the beneficial effects of sulforaphane (SFN), which is the most studied member of isothiocyanates, on both in vivo and in vitro models of different diseases, mainly diabetes and cancer. The role of SFN on oxidative stress, inflammation, and metabolism is discussed, with emphasis on those nuclear factor E2-related factor 2 (Nrf2) pathway-mediated mechanisms. In the case of the anti-inflammatory effects of SFN, the point of convergence seems to be the downregulation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), with the consequent amelioration of other pathogenic processes such as hypertrophy and fibrosis. We emphasized that SFN shows opposite effects in normal and cancer cells at many levels; for instance, while in normal cells it has protective actions, in cancer cells it blocks the induction of factors related to the malignity of tumors, diminishes their development, and induces cell death. SFN is able to promote apoptosis in cancer cells by many mechanisms, the production of reactive oxygen species being one of the most relevant ones. Given its properties, SFN could be considered as a phytochemical at the forefront of natural medicine.

In Vitro Modulation of Redox and Metabolism Interplay at the Brain Vascular Endothelium: Genomic and Proteomic Profiles of Sulforaphane Activity

Sulforaphane (SFN) has been shown to protect the brain vascular system and effectively reduce ischemic injuries and cognitive deficits. Given the robust cerebrovascular protection afforded by SFN, the objective of this study was to profile these effects in vitro using primary mouse brain microvascular endothelial cells and focusing on cellular redox, metabolism and detoxification functions. We used a mouse MitoChip array developed and validated at the FDA National Center for Toxicological Research (NCTR) to profile a host of genes encoded by nuclear and mt-DNA following SFN treatment (0-5 µM). Corresponding protein expression levels were assessed (ad hoc) by qRT-PCR, immunoblots and immunocytochemistry (ICC). Gene ontology clustering revealed that SFN treatment (24 h) significantly up-regulated ~50 key genes (>1.5 fold, adjusted p < 0.0001) and repressed 20 genes (<0.7 fold, adjusted p < 0.0001) belonging to oxidative stress, phase 1 & 2 drug metabolism enzymes (glutathione system), iron transporters, glycolysis, oxidative phosphorylation (OXPHOS), amino acid metabolism, lipid metabolism and mitochondrial biogenesis. Our results show that SFN stimulated the production of ATP by promoting the expression and activity of glucose transporter-1, and glycolysis. In addition, SFN upregulated anti-oxidative stress responses, redox signaling and phase 2 drug metabolism/detoxification functions, thus elucidating further the previously observed neurovascular protective effects of this compound.

Protective effects of the astaxanthin derivative, adonixanthin, on brain hemorrhagic injury

Astaxanthin is beneficial for human health and is used as a dietary supplement. The present study was performed in order to examine the protective effects of the astaxanthin derivative, adonixanthin, against cell death caused by hemoglobin, collagenase, lipopolysaccharide, and hydrogen peroxide, which are associated with hemorrhagic brain injury. In an in vitro study, adonixanthin exerted cytoprotective effects against each type of damage, and its effects were stronger than those of astaxanthin. The increased production of reactive oxygen species in human brain endothelial cells in the hemoglobin treatment group was inhibited by adonixanthin. Moreover, adonixanthin suppressed cell death in SH-SY5Y cells. In an in vivo study, the oral administration of adonixanthin improved blood-brain barrier hyper-permeability in an autologous blood ICH model. We herein demonstrated for the first time that adonixanthin exerted protective effects against hemorrhagic brain damage by activating antioxidant defenses, and has potential as a protectant against intracerebral hemorrhage.

P-glycoprotein (ABCB1) and Oxidative Stress: Focus on Alzheimer's Disease

ATP-binding cassette (ABC) transporters, in particular P-glycoprotein (encoded by ABCB1), are important and selective elements of the blood-brain barrier (BBB), and they actively contribute to brain homeostasis. Changes in ABCB1 expression and/or function at the BBB may not only alter the expression and function of other molecules at the BBB but also affect brain environment. Over the last decade, a number of reports have shown that ABCB1 actively mediates the transport of beta amyloid (Aβ) peptide. This finding has opened up an entirely new line of research in the field of Alzheimer's disease (AD). Indeed, despite intense research efforts, AD remains an unsolved pathology and effective therapies are still unavailable. Here, we review the crucial role of ABCB1 in the Aβ transport and how oxidative stress may interfere with this process. A detailed understanding of ABCB1 regulation can provide the basis for improved neuroprotection in AD and also enhanced therapeutic drug delivery to the brain.

Curcumin mitigates cerebral vasospasm and early brain injury following subarachnoid hemorrhage via inhibiting cerebral inflammation

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH)-induced cerebral vasospasm and early brain injury is a fatal clinical syndrome. Cerebral vasospasm and early brain injury are associated with inflammatory response and oxidative stress. Whether curcumin, which plays important roles to regulate inflammatory cytokines and inhibit oxidative stress, inhibits SAH-induced inflammation and oxidative stress are largely unknown.

METHODS

Adult male rats underwent autologous blood injection into prechiasmatic cistern to induce SAH. Curcumin (150 mg/kg) was administered at 0.5, 24 and 48 hr post-SAH. Mortality calculation and neurological outcomes as well as morphological vasospasm of anterior cerebral artery were studied. Superoxide dismutase, lipid peroxidation, and inflammatory cytokines (MCP-1 and TNF-α) expression in prefrontal region were quantified. Furthermore, p65 and phosphor-p65 were quantitatively analyzed.

RESULTS

Curcumin remarkedly reduced mortality and ameliorated neurological deficits after SAH induction (p < .05); morphological results showed that cerebral vasospasm in curcumin-treated group was mitigated (p < .05). SAH-induced MCP-1 and TNF-α overexpression were inhibited in curcumin-treated group (p < .05). Importantly, phosphor-p65 was significantly inhibited after curcumin treatment (p < .05).

CONCLUSIONS

Curcumin can inhibit SAH-induced inflammatory response via restricting NF-κB activation to alleviate cerebral vasospasm and early brain injury.

Actinidia chinensis Planch. Improves the Indices of Antioxidant and Anti-Inflammation Status of Type 2 Diabetes Mellitus by Activating Keap1 and Nrf2 via the Upregulation of MicroRNA-424

The fruit juice of Actinidia chinensis Planch. has antioxidant and anti-inflammation properties on patients with type 2 diabetes mellitus (T2DM), but the molecular mechanism was unclear. The patients took the juice and the serum level of antioxidant miR-424, Kelch-like ECH-associated protein 1 (Keap1), erythroid-derived 2-like 2 (Nrf2), and biochemical indices were measured. The juice increased the levels of serum microRNA-424, Keap1, and Nrf2 and reduced the levels of interleukin-1 (IL-1) beta and IL-6 in T2DM patients. The levels of SOD and GSH were higher while the levels of ALT and AST were lower in the patients consuming the juice when compared to the patients without taking the juice. The Spearman rank correlation analysis showed that the serum levels of miR-424 were positively related to Keap1 and Nrf2 levels while Keap1 and Nrf2 levels were positively related to the levels of SOD and GSH and negatively related to IL-1 beta and IL-6. Thus, FJACP improves the indices of antioxidant and anti-inflammation status by activating Keap1 and Nrf2 via the upregulation of miR-424 in the patients with T2DM. This trial is registered with ChiCTR-ONC-17011087 on 04/07/2017.

Sulforaphane Protects against Brain Diseases: Roles of Cytoprotective Enzymes

Sulforaphane (SFN) is a kind of isothiocyanate derived from broccoli and other cruciferous vegetables. Because of its roles of antioxidant, anti-inflammatory, and anti-tumor through multiple targets and various mechanisms, SFN has drawn broad attention of the researchers. One of the most important target of SFN is nuclear factor erythroid 2 related factor 2 (Nrf2), wildly known for its ability to regulate the expression of a series of cytoprotective enzymes with antioxidative, prosurvival, and detoxification effects. Multiple researches have shown that SFN protects against central nervous system diseases through Nrf2pathway. In this article, we list SFN contents in common cruciferous vegetables, and summarize recent advances in the protective effects of SFN against acute brain injuries and neurodegenerative diseases through activating Nrf2 signaling pathway.