Inhibition of JNK Alleviates Chronic Hypoperfusion-Related Ischemia Induces Oxidative Stress and Brain Degeneration via Nrf2/HO-1 and NF-κB Signaling

Acupoint catgut embedding attenuates oxidative stress and cognitive impairment in chronic cerebral ischemia by inhibiting the Ang II/AT1R/NOX axis

Chronic cerebral ischemia (CCI) is a common neurological disorder, characterized by progressive cognitive impairment. Acupoint catgut embedding (ACE) represents a modern acupuncture form that has shown neuroprotective effects; nevertheless, its effects on CCI and the mechanisms remain largely unknown. Here, we aimed to explore the therapeutic action of ACE in CCI-induced cognitive impairment and its mechanisms. The cognitive function of CCI rats was determined using Morris water maze test, and histopathological changes in the brain were assessed through hematoxylin-eosin (HE) staining. To further explore the molecular mechanisms, the expression levels of oxidative stress markers and the Ang II/AT1R/NOX axis-associated molecules in the hippocampus were evaluated using enzyme-linked immunosorbent assay (ELISA), western blotting, and immunohistochemistry. Here, we observed that ACE treatment alleviated cognitive dysfunction and histopathological injury in CCI rats. Intriguingly, candesartan (an AT1R blocker) enhanced the beneficial effects of ACE on ameliorating cognitive impairment in CCI rats. Mechanistically, ACE treatment blocked the Ang II/AT1R/NOX pathway and subsequently suppressed oxidative stress, thus mitigating cognitive impairment in CCI. Our findings first reveal that ACE treatment could suppress cognitive impairment in CCI, which might be partly due to the suppression of Ang II/AT1R/NOX axis.

Inhibitory effect of Incarvillea diffusa Royle extract in the formation of calcium oxalate nephrolithiasis by regulating ROS-induced Nrf2/HO-1 pathway in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Calcium oxalate (CaOx) kidney stones are widely acknowledged as the most prevalent type of urinary stones, with high incidence and recurrence rates. Incarvillea diffusa Royle (ID) is a traditionally used medicinal herb in the Miao Minzu of Guizhou province, China, for treating urolithiasis. However, the active components and the underlying mechanism of its pharmacodynamic effects remain unclear.

AIM OF THE STUDY

This study aimed to investigate the potential inhibitory effect of the active component of ID on the formation of CaOx nephrolithiasis and elucidate the underlying mechanism.

MATERIALS AND METHODS

In vivo, a CaOx kidney stone model was induced in Sprague-Dawley (SD) rats using an ethylene glycol and ammonium chloride protocol for four weeks. Forty-eight male SD rats were randomly assigned to 6 groups (n = 8): blank group, model group, apocynin group, and low, medium, and high dose of ID's active component (IDW) groups. After three weeks of administration, rat urine, serum, and kidney tissues were collected. Renal tissue damage and crystallization, Ox, BUN, Ca2+, CRE, GSH, MDA, SOD contents, and levels of IL-1β, IL-18, MCP-1, caspase-1, IL-6, and TNF-α in urine, serum, and kidney tissue were assessed using HE staining and relevant assay kits, respectively. Protein expression of Nrf2, HO-1, p38, p65, and Toll-4 in kidney tissues was quantified via Western blot. The antioxidant capacities of major compounds were evaluated through DPPH, O2·-, and ·OH radical scavenging assays, along with their effects on intracellular ROS production in CaOx-induced HK-2 cells.

RESULTS

We found that IDW could significantly reduce the levels of CRE, GSH, MDA, Ox, and BUN, and enhancing SOD activity. Moreover, it could inhibit the secretion of TNF-α, IL-1β, IL-18, MCP-1, caspase-1, and decreased protein expression of Nrf2, HO-1, p38, p65, and Toll-4 in renal tissue. Three major compounds isolated from IDW exhibited promising antioxidant activities and inhibited intracellular ROS production in CaOx-induced HK-2 cells.

CONCLUSIONS

IDW facilitated the excretion of supersaturated Ca2+ and decreased the production of Ox, BUN in SD rat urine, and mitigated renal tissue damage by regulating Nrf2/HO-1 signaling pathway. Importantly, the three major compounds identified as active components of IDW contributed to the inhibition of CaOx nephrolithiasis formation. Overall, IDW holds significant potential for treating CaOx nephrolithiasis.

Impact of intraoperative dexmedetomidine on postoperative delirium and pro-inflammatory cytokine levels in elderly patients undergoing thoracolumbar compression fracture surgery: A prospective, randomized, placebo-controlled clinical trial

BACKGROUND

This study evaluates the efficacy of dexmedetomidine (DEX) in reducing postoperative delirium (POD) and modulating pro-inflammatory cytokines in elderly patients undergoing thoracolumbar compression fracture surgery.

METHODS

In this randomized, double-blind, placebo-controlled trial conducted from October 2022 to January 2023 at Anting Hospital in Shanghai, 218 elderly patients were randomized into DEX (n = 110) and normal saline (NS, n = 108) groups. The DEX group received 0.5 µg/kg/h DEX, and delirium incidence was assessed using the Confusion Assessment Method (CAM) on days 1 to 3 post-surgery. Levels of interleukins IL-1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured pre-operation (T0) and on postoperative days 1 (T1) and 3 (T3). Preoperative (T0) and postoperative day 1 (T1) cerebrospinal fluid (CSF) samples were treated with varying concentrations of olanzapine or DEX to observe their regulatory effects on the expression of Phospho-ERK1/2 and Phospho-JNK.

RESULTS

Dexmedetomidine significantly lowered the incidence of POD to 18.2%, compared to 30.6% in the NS group (P = .033). While all patients showed an initial increase in cytokine levels after surgery, by T3, IL-6 and TNF-α levels notably decreased in the DEX group, with no significant change in IL-1β levels across groups. The adverse events rate was similar between groups, demonstrating the safety of DEX in this population. In postoperative CSF samples, treatment with 0.5 mM DEX significantly downregulated Phospho-JNK and upregulated Phospho-ERK1/2 expression, demonstrating a dose-dependent modulation of inflammatory responses.

CONCLUSION

Dexmedetomidine is effective in reducing early POD in elderly patients post-thoracolumbar compression fracture surgery. It also decreases IL-6 and TNF-α levels, indicating its potential in managing postoperative inflammatory responses. Treatment with 0.5 mM DEX significantly modulated Phospho-ERK1/2 and Phospho-JNK expressions in postoperative CSF samples, indicating a dose-dependent effect on reducing inflammation. This study contributes to understanding DEX's role in improving postoperative outcomes in elderly patients.

Piceatannol selectively inhibited the JNK3 enzyme and augmented apoptosis through inhibition of Bcl-2/Cyt-c/caspase-dependent pathways in the oxygen-glucose deprived SHSY-5Y cell lines: In silico and in vitro study

JNK3, a neuronal kinase activated by stress, plays a role in stress-induced apoptosis, leading to neuronal cell death following cerebral ischemia. This study investigates the neuroprotective effects of piceatannol (PCT) in SHSY-5Y neuroblastoma cells after hypoxic injury and its interaction with JNK3. We analyzed the crystal coordinates, interaction energies, and amino acid interactions to determine PCT's selectivity for JNK3. The electrostatic potential was computed using density functional theory, while molecular dynamics assessed the stability and structural consistency of the JNK3-PCT complex. We used SP600125 (SP6), a JNK3 inhibitor, as a reference compound. Additionally, we performed cell-free JNK 1, 2, and 3 kinase assays to evaluate the isoform selectivity of PCT. Cytotoxicity and cell viability were determined by an MTT test. To assess apoptosis, we used acridine orange/ethidium bromide dual fluorescent labeling and ANNEXIN A5-FITC flow cytometry. Western blot was used to evaluate the attenuation of JNK3 and apoptotic proteins. In silico studies revealed a stronger binding affinity between PCT and JNK3 compared to JNK1 and JNK2, which was further supported by the in vitro kinase assay. PCT-treated cells exhibited a decrease in Cyt-c and caspase-3 expression and an increase in Bcl-2 level, compared to hypoxic control (p < .001). PCT also demonstrated superior efficacy over SP6 in inhibiting JNK3 phosphorylation (p < .001). Furthermore, PCT significantly increased the expression of neuronal genes, including NgN1, neuroD2, and survivin (p < .001). In conclusion, PCT is a potential JNK3 inhibitor, since it inhibited phosphorylation and the Bcl-2/Cyt-C/caspase-3-dependent apoptotic pathway after ischemic/hypoxic insult.

Piceatannol improved cerebral blood flow and attenuated JNK3 and mitochondrial apoptotic pathway in a global ischemic model to produce neuroprotection

Cerebral ischemia is one of the leading causes of death and disability worldwide. The only FDA-approved treatment is recanalization with systemic tissue plasminogen activators like alteplase, although reperfusion caused by recanalization can result in neuroinflammation, which can cause brain cell apoptosis. Therefore, after an ischemic/reperfusion injury, interventions are needed to minimize the neuroinflammatory cascade. In the present study, piceatannol (PCT) was studied for its neuroprotective efficacy in a rat model of global ischemic injury by attenuating c-Jun N-terminal kinase 3 (JNK3) downstream signaling. PCT is a resveratrol analog and a polyphenolic stilbenoid naturally occurring in passion fruit and grapes. The neuroprotective efficacy of PCT (1, 5, 10 mg/kg) in ischemic conditions was assessed through pre- and post-treatment. Cerebral blood flow (CBF) and tests for functional recovery were assessed. Protein and gene expression were done for JNK3 and other inflammatory markers. A docking study was performed to identify the amino acid interaction. The results showed that PCT improved motor and memory function as measured by a functional recovery test believed to be due to an increase in cerebral blood flow. Also, the caspase signaling which promotes apoptosis was found to be down-regulated; however, nitric oxide synthase expression was up-regulated, which could explain the enhanced cerebral blood flow (CBF). According to our findings, PCT impeded c-Jun N-terminal kinase 3 (JNK3) signaling by suppressing phosphorylation and disrupting the mitochondrial apoptotic pathway, which resulted in the neuroprotective effect. Molecular docking analysis was performed to investigate the atomic-level interaction of JNK3 and PCT, which reveals that Met149, Leu206, and Lys93 amino acid residues are critical for the interaction of PCT and JNK3. According to our current research, JNK3 downstream signaling and the mitochondrial apoptosis pathway are both inhibited by PCT, which results in neuroprotection under conditions of global brain ischemia. Piceatannol attenuated JNK3 phosphorylation during the ischemic condition and prevented neuronal apoptosis.

Protective role of hesperetin in sorafenib-induced hepato- and neurotoxicity in mice via modulating apoptotic pathways and mitochondrial reprogramming

INTRODUCTION

Sorafenib, an FDA-approved standard chemotherapy for advanced hepatocellular carcinoma, is associated with numerous adverse effects that significantly impact patients' physiological well-being. Consequently, identifying agents that mitigate these side effects while enhancing efficacy is crucial. Hesperetin, a flavone present in fruits and vegetables, possesses antioxidant, anti-inflammatory, and anti-cancer properties. This study aimed to investigate the hepatotoxic and neurotoxic effects of sorafenib and the potential protective role of hesperetin.

MATERIALS AND METHODS

Swiss albino mice were orally administered sorafenib (100 mg/kg) alone or in combination with hesperetin (50 mg/kg) over 21 days. Behavioral assessments for anxiety and depressive-like behaviors were conducted. Additionally, evaluations encompassed apoptotic activity, mitochondrial integrity, liver enzyme levels, proliferation rates, and histopathological changes.

RESULTS

Combining hesperetin with sorafenib showed improvements in behavioral alterations, liver damage, brain mitochondrial dysfunction, and liver apoptosis compared to the sorafenib-only group in mice.

CONCLUSION

Hesperetin exhibits potential as an adjunct to sorafenib, mitigating its side effects by attenuating its toxicity, enhancing efficacy, and potentially reducing the occurrence of sorafenib-induced resistance through the downregulation of hepatocyte growth factor levels.

Nrf2: Therapeutic target of islet function protection in diabetes and islet transplantation

Nuclear factor-erythroid 2-related factor 2 (Nrf2) has been reported as a major intracellular regulator of antioxidant stress, notably in islet β cells with low antioxidant enzyme content. Nrf2 is capable of regulating antioxidant function, while it can also regulate insulin secretion, proliferation, and differentiation of β cells, ER stress, as well as mitochondrial function. Thus, Nrf2 pharmacological activators have been employed in the laboratory for the treatment of diabetic mice. Islet cells are exposed to oxidative environment when islet is being transplanted. Accordingly, less than 50% of islet cells are well transplanted, and their normal function is maintained. The pharmacological activation of Nrf2 has been confirmed to protect islet cells at different stages of transplantation stages during experiments for islet transplantation.

Purpurin ameliorates D-galactose-induced aging phenotypes in mouse hippocampus by reducing inflammatory responses

Purpurin, an anthraquinone, has potent anti-oxidant and anti-inflammatory effects in various types of brain damage. In a previous study, we showed that purpurin exerts neuroprotective effects against oxidative and ischemic damage by reducing pro-inflammatory cytokines. In the present study, we investigated the effects of purpurin against D-galactose-induced aging phenotypes in mice. Exposure to 100 mM D-galactose significantly decreased cell viability in HT22 cells, and purpurin treatment significantly ameliorated the reduction of cell viability, formation of reactive oxygen species, and lipid peroxidation in a concentration-dependent manner. Treatment with 6 mg/kg purpurin significantly improved D-galactose-induced memory impairment in the Morris water maze test in C57BL/6 mice and alleviated the reduction of proliferating cells and neuroblasts in the subgranular zone of the dentate gyrus. In addition, purpurin treatment significantly mitigated D-galactose-induced changes of microglial morphology in the mouse hippocampus and the release of pro-inflammatory cytokines such as interleukin-1β, interleukin-6, and tumor necrosis factor-α. In addition, purpurin treatment significantly ameliorated D-galactose-induced phosphorylation of c-Jun N-terminal kinase and cleavage of caspase-3 in HT22 cells. These results suggest that purpurin can delay aging by reducing the inflammatory cascade and phosphorylation of the c-Jun N-terminal in the hippocampus.

Imperatorin exerts antioxidant effects in vascular dementia via the Nrf2 signaling pathway

Imperatorin, an active ingredient extracted from Angelica and Qianghuo, has anti-inflammatory, anti-oxidative stress damage, blocking calcium channels, and other properties. Our preliminary findings revealed the protective role of imperatorin in the treatment of vascular dementia, we further explored the underlying mechanisms concerning the neuroprotection function of imperatorin in vascular dementia. The cobalt chloride (C_OCl2)-induced chemical hypoxia and hypoglycemia of hippocampal neuronal cells was applied as in vitro vascular dementia model. Primary neuronal cells was isolated from the hippocampal tissue of SD suckling rats within 24 h of birth. Hippocampal neurons were identified by immunofluorescence staining of microtubule-associated protein 2. Silencing or overexpression of Nrf2 was conducted by transfection of corresponding plasmids in hippocampal neuronal cells. Cell viability was detected by MTT assay to determine the optimal modeling concentration of CoCl2. Mitochondrial membrane potential, intracellular reactive oxygen species and apoptosis rate was measured by flow cytometry. The expression of anti-oxidative proteins was detected by quantitative real-time PCR and western blot, including Nrf2, NQO-1 and HO-1. Nrf2 nuclear translocation was detected using laser confocal microscopy. The modeling concentration of CoCl2 was 150umol/l, and the best interventional concentration of imperatorin was 7.5umol/l. Significantly, imperatorin facilitated the nuclear localization of Nrf2, promoted the expressions of Nrf2, NQO-1, and HO-1 relative to the model-control group. Moreover, imperatorin reduced the mitochondrial membrane potential and ameliorated CoCl2-induced hypoxic apoptosis in hippocampal neurons. On the contrary, silencing Nrf2 completely abrogated the protective effects of imperatorin. Imperatorin might be an effective drug for preventing and treating vascular dementia.

Zinc supplementation ameliorates sorafenib-induced cognitive impairment through ROS/JNK signaling pathway

Sorafenib, a multiple kinase inhibitor, is widely used in cancer patients. Recently, clinical studies highlighted the relationship between cognitive deficits and sorafenib exposure. Zinc abundant in the body has been reported to exert neuroprotective activities. However, the effects of zinc supplementation on sorafenib-induced cognitive impairment are still unknown. In the current study, we verified that mice challenged with sorafenib displayed characteristic features of cognitive impairment. However, zinc treatment effectively improved these changes. Histopathological staining also showed that zinc significantly alleviated hippocampal microstructural and ultrastructural damages induced by sorafenib. Meanwhile, zinc significantly reduced sorafenib-induced ROS production and neuronal cells apoptosis in vivo and vitro. Additionally, we also investigated whether zinc protected against sorafenib-induced neuronal cells apoptosis via ROS/JNK pathway through treating SH-SY5Y cells with the NAC or the specific JNK activator anisomycin. The results indicated that NAC performed the same protective effects as zinc in sorafenib-challenged SH-SY5Y cells and activation of JNK by anisomycin partly abolished the protective effects of zinc. Collectively, the present study suggested that inhibition of oxidative stress and the JNK pathway might contribute to the protective effects of zinc against sorafenib-caused cognitive impairment in vivo and vitro.

Involvement of the gut-brain axis in vascular depression via tryptophan metabolism: A benefit of short chain fatty acids

Cerebral hemodynamic dysfunction and hypoperfusion have been found to underlie vascular depression, but whether the gut-brain axis is involved remains unknown. In this study, a rat model of bilateral common carotid artery occlusion (BCCAO) was adopted to mimic chronic cerebral hypoperfusion. A reduced sucrose preference ratio, increased immobility time in the tail suspension test and forced swim test, and compromised gut homeostasis were found. A promoted conversion of tryptophan (Trp) into kynurenine (Kyn) instead of 5-hydroxytryptamine (5-HT) was observed in the hippocampus and gut of BCCAO rats. Meanwhile, 16S ribosomal RNA gene sequencing suggested a compromised profile of the gut SCFA-producing microbiome, with a decreased serum level of SCFAs revealed by targeted metabolomics analysis. With SCFA supplementation, BCCAO rats exhibited ameliorated depressive-like behaviors and improved gut dysbiosis, compared with the salt-matched BCCAO group. Enzyme-linked immunosorbent assays and quantitative RT-PCR suggested that SCFA supplementation suppressed the conversion of Trp to Kyn and rescued the reduction in 5-HT levels in the hippocampus and gut. In addition to inhibiting the upregulation of inflammatory cytokines, SCFA supplementation ameliorated the activated oxidative stress and reduced the number of microglia and the expression of its proinflammatory markers in the hippocampus post BCCAO. In conclusion, our data suggested the participation of the gut-brain axis in vascular depression, shedding light on the neuroprotective potential of treatment with gut-derived SCFAs.

RETRACTED: Carveol ameliorates mercury-induced oxidative stress, neuroinflammation, and neurodegeneration in a mouse brain

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief. Sections of panels from Figure 7B appear similar to each other. Also, inconsistencies have been noticed between the text of the subsection 2.5.4. ‘Morris Water Maze (MWM) test’ and Figure 6E. The journal records indicated that the names of the authors Sajid Rashid, Nadia Hussain, Mehreen Gul, Muhammad Ikram and Jingbo Li were added to the revised version of the article without exceptional approval by the handling Editor, which is contrary to the journal policy on changes to authorship.

Targeting Nrf2 in ischemia-reperfusion alleviation: From signaling networks to therapeutic targeting

The nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of redox balance and it responds to various cell stresses that oxidative stress is the most well-known one. The Nrf2 should undergo nuclear translocation to exert its protective impacts and decrease ROS production. On the other hand, ischemic/reperfusion (I/R) injury is a pathological event resulting from low blood flow to an organ and followed by reperfusion. The I/R induces cell injury and organ dysfunction. The present review focuses on Nrf2 function in alleviation of I/R injury. Stimulating of Nrf2 signaling ameliorates I/R injury in various organs including lung, liver, brain, testis and heart. The Nrf2 enhances activity of antioxidant enzymes to reduce ROS production and prevent oxidative stress-mediated cell death. Besides, Nrf2 reduces inflammation via decreasing levels of pro-inflammatory factors including IL-6, IL-1β and TNF-α. Nrf2 signaling is beneficial in preventing apoptosis and increasing cell viability. Nrf2 induces autophagy to prevent apoptosis during I/R injury. Furthermore, it can interact with other molecular pathways including PI3K/Akt, NF-κB, miRNAs, lncRNAs and GSK-3β among others, to ameliorate I/R injury. The therapeutic agents, most of them are phytochemicals such as resveratrol, berberine and curcumin, induce Nrf2 signaling in I/R injury alleviation.

Lupeol Treatment Attenuates Activation of Glial Cells and Oxidative-Stress-Mediated Neuropathology in Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) signifies a major cause of death and disability. TBI causes central nervous system (CNS) damage under a variety of mechanisms, including protein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammation. Astrocytes and microglia, cells of the CNS, are considered the key players in initiating an inflammatory response after injury. Several evidence suggests that activation of astrocytes/microglia and ROS/LPO have the potential to cause more harmful effects in the pathological processes following traumatic brain injury (TBI). Previous studies have established that lupeol provides neuroprotection through modulation of inflammation, oxidative stress, and apoptosis in Aβ and LPS model and neurodegenerative disease. However, the effects of lupeol on apoptosis caused by inflammation and oxidative stress in TBI have not yet been investigated. Therefore, we explored the role of Lupeol on antiapoptosis, anti-inflammatory, and antioxidative stress and its potential mechanism following TBI. In these experiments, adult male mice were randomly divided into four groups: control, TBI, TBI+ Lupeol, and Sham group. Western blotting, immunofluorescence staining, and ROS/LPO assays were performed to investigate the role of lupeol against neuroinflammation, oxidative stress, and apoptosis. Lupeol treatment reversed TBI-induced behavioral and memory disturbances. Lupeol attenuated TBI-induced generation of reactive oxygen species/lipid per oxidation (ROS/LPO) and improved the antioxidant protein level, such as nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1 (HO-1) in the mouse brain. Similarly, our results indicated that lupeol treatment inhibited glial cell activation, p-NF-κB, and downstream signaling molecules, such as TNF-α, COX-2, and IL-1β, in the mouse cortex and hippocampus. Moreover, lupeol treatment also inhibited mitochondrial apoptotic signaling molecules, such as caspase-3, Bax, cytochrome-C, and reversed deregulated Bcl2 in TBI-treated mice. Overall, our study demonstrated that lupeol inhibits the activation of astrocytes/microglia and ROS/LPO that lead to oxidative stress, neuroinflammation, and apoptosis followed by TBI.

The Development of Novel Drug Treatments for Stroke Patients: A Review

Acute ischemic stroke is a critical condition that can result in disability and death. The consequences of this medical condition depend on various factors, including the size of the stroke, affected brain region, treatment onset, and the type of treatment. The primary objective of stroke treatment is to restart ischemic penumbra tissue perfusion and reduce infarct volume by sustaining blood flow. Recent research on the condition’s pathological pathways and processes has significantly improved treatment options beyond restoring perfusion. Many studies have concentrated on limiting injury severity via the manipulation of molecular mechanisms of ischemia, particularly in animal research. This article reviews completed and ongoing research on the development of acute ischemic stroke drugs. This study focuses on three main categories of antithrombotic drugs, thrombolytic drugs, and neuroprotective agents. The paper outlines findings from animal and clinical trials and explores the working mechanisms of these drugs.

Effect of Crocin From Saffron (Crocus sativus L.) Supplementation on Oxidant/Antioxidant Markers, Exercise Capacity, and Pulmonary Function Tests in COPD Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

Background: Chronic obstructive pulmonary disease (COPD) is a progressive and chronic respiratory disorder characterized by reversible airflow limitation and lung parenchyma destruction. The main feature of COPD is inflammation and disturbance of the oxidant/antioxidant balance in the airways. The therapeutic use of herbal supplements with antioxidant and anti-inflammatory properties seems to be very useful in the medical management of patients with COPD. Method: COPD patients were divided into placebo and intervention groups (each group n = 23) in a clinical trial study. The intervention group received crocin supplementation (30 mg/day for 12 weeks), and the control group received a placebo. Pre- and after the intervention, pulmonary function tests (PFTs), exercise capacity (using a 6-min walking distance test (6MWD)), and serum levels of total oxidant status (TOS), total antioxidant capacity (TAOC), and NF-kB were assessed using the ELISA test. Results: Intervention with crocin for 12 weeks in COPD patients decreased serum levels of TOS and NF-κB as well as increased TAOC. In addition, the results of the 6MWD test reveal an improvement in patients' exercise capacity. Conclusion: Crocin supplementation appears to effectively establish oxidant/antioxidant balance and improve inflammatory conditions in patients with COPD.

Endoplasmic Reticulum Stress and the Unfolded Protein Response in Cerebral Ischemia/Reperfusion Injury

Ischemic stroke is an acute cerebrovascular disease characterized by sudden interruption of blood flow in a certain part of the brain, leading to serious disability and death. At present, treatment methods for ischemic stroke are limited to thrombolysis or thrombus removal, but the treatment window is very narrow. However, recovery of cerebral blood circulation further causes cerebral ischemia/reperfusion injury (CIRI). The endoplasmic reticulum (ER) plays an important role in protein secretion, membrane protein folding, transportation, and maintenance of intracellular calcium homeostasis. Endoplasmic reticulum stress (ERS) plays a crucial role in cerebral ischemia pathophysiology. Mild ERS helps improve cell tolerance and restore cell homeostasis; however, excessive or long-term ERS causes apoptotic pathway activation. Specifically, the protein kinase R-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1) pathways are significantly activated following initiation of the unfolded protein response (UPR). CIRI-induced apoptosis leads to nerve cell death, which ultimately aggravates neurological deficits in patients. Therefore, it is necessary and important to comprehensively explore the mechanism of ERS in CIRI to identify methods for preserving brain cells and neuronal function after ischemia.

Genistein mitigates oxidative stress and inflammation by regulating Nrf2/HO-1 and NF-κB signaling pathways in hypoxic-ischemic brain damage in neonatal mice

Background

Oxidative stress and neuroinflammation play crucial roles in the progression of neonatal hypoxic-ischemic brain damage (HIBD). Genistein, a natural phytoestrogen, has been found to protect against ischemic brain injury. However, its effects and potential mechanisms in HIBD have not yet been explored.

Methods

A neonatal mouse model of hypoxia-ischemia (HI) and a cell model of oxygen-glucose deprivation/reperfusion (OGD/R) were employed. In the in vivo study, genistein (10 mg/kg; ip) was administered in mice once daily for 3 consecutive days before the operation and once immediately after HI. The effects of genistein treatment on acute brain damage and long-term responses were evaluated. Neuronal injury and apoptosis were estimated using hematoxylin and eosin (H&E) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, respectively. The expression of apoptosis-related proteins were also measured by Western blot analysis. Dihydroethidium (DHE) staining and glutathione (GSH) and malondialdehyde (MDA) production were determined to assess the extent of oxidative stress. The messenger RNA (mRNA) levels of proinflammatory cytokines were detected using real-time quantitative polymerase chain reaction (RT-qPCR) to evaluate the extent of neuroinflammation. In the in vitro study, cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) assays, as well as propidium iodide (PI) staining, were performed to analyse the neuroprotective effects of genistein on primary cortical neurons. Western blot assays were used to detect the levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), phosphorylated inhibitor kappa B-α (p-IκB-α) and phosphorylated nuclear factor-kappa B (p-NF-κB) both in vivo and in vitro.

Results

Our results showed that genistein treatment effectively reduced cerebral infarction, attenuated neuronal injury and apoptosis, and contributed to the long-term recovery of neurological outcomes and brain atrophy in neonatal HIBD mice. Moreover, genistein ameliorated HIBD-induced oxidative stress and neuroinflammation. Meanwhile, genistein significantly increased cell viability, reversed neuronal injury and decreased cell apoptosis after OGD/R injury. Finally, the activation of the Nrf2/HO-1 pathway and inhibition of the NF-κB pathway by genistein were verified in the brain tissues of neonatal mice subjected to HIBD and in primary cortical neurons exposed to OGD/R.

Conclusions

Genistein exerted neuroprotective effects on HIBD by attenuating oxidative stress and neuroinflammation through the Nrf2/HO-1 and NF-κB signalling pathways.

Tannic acid protects aged brain against cerebral hypoperfusion via modulation of Nrf2 and inflammatory pathways

Current study purposed to investigate the neuroprotective effects of Tannic Acid (TA) on mild chronic cerebral hypoperfusion model in rats. Male Wistar rats were subjected to permanent Unilateral Common Carotid Artery Occlusion (UCCAO), followed by TA treatment (0.05% w/v) in drinking water for one month. Nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO-1), heme oxygenase-1 (HO-1), factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor-α (TNF-α), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, blood triglyceride, blood glucose, and liver enzymes' activity were detected after the experimental period. Also, behavioral tests, hematoxylin and eosin (H&E) staining, and PET scan were performed after treatment. Post-treatment of TA improved locomotion and memory function (P < 0.001), and reduced neural cell death (P < 0.001) in the treatment group compared to UCCAO rats. Furthermore, long-term TA treatment significantly increased the levels of Nrf2 (P < 0.001), NQO-1 (P < 0.001), and HO-1 (P < 0.001) in the hippocampus of the treatment group compared to the UCCAO group. TA consumption in the treatment group applied its anti-inflammatory effects via reducing the activity of NF-κB and TNF-α in comparison with the UCCAO group (P < 0.001 for both). Blood triglyceride, blood glucose, and liver enzymes did not change considerably in the groups (P > 0.05). The current results indicate that long-term post-treatment of TA exhibits protective effects against memory deficit and motor dysfunction. The cellular mechanism of TA in hypoperfused rats might be associated with the activation of antioxidant pathways, especially the Nrf2 pathway, and suppressing inflammatory factors like NF-κB and TNF-α.

Cycloastragenol, a Triterpenoid Saponin, Regulates Oxidative Stress, Neurotrophic Dysfunctions, Neuroinflammation and Apoptotic Cell Death in Neurodegenerative Conditions

Here, we have unveiled the effects of cycloastragenol against Aβ (Amyloid-beta)-induced oxidative stress, neurogenic dysfunction, activated mitogen-activated protein (MAP) kinases, and mitochondrial apoptosis in an Aβ-induced mouse model of Alzheimer's disease (AD). The Aβ-induced mouse model was developed by the stereotaxic injection of amyloid-beta (5 μg/mouse/intracerebroventricular), and cycloastragenol was given at a dose of 20 mg/kg/day/p.o for 6 weeks daily. For the biochemical analysis, we used immunofluorescence and Western blotting. Our findings showed that the injection of Aβ elevated oxidative stress and reduced the expression of neurogenic markers, as shown by the reduced expression of brain-derived neurotrophic factor (BDNF) and the phosphorylation of its specific receptor tropomyosin receptor kinase B (p-TrKB). In addition, there was a marked reduction in the expression of NeuN (neuronal nuclear protein) in the Aβ-injected mice brains (cortex and hippocampus). Interestingly, the expression of Nrf2 (nuclear factor erythroid 2-related factor 2), HO-1 (heme oxygenase-1), p-TrKB, BDNF, and NeuN was markedly enhanced in the Aβ + Cycloastragenol co-treated mice brains. We have also evaluated the expressions of MAP kinases such as phospho c-Jun-N-terminal kinase (p-JNK), p-38, and phospho-extracellular signal-related kinase (ERK1/2) in the experimental groups, which suggested that the expression of p-JNK, p-P-38, and p-Erk were significantly upregulated in the Aβ-injected mice brains; interestingly, these markers were downregulated in the Aβ + Cycloastragenol co-treated mice brains. We also checked the expression of activated microglia and inflammatory cytokines, which showed that cycloastragenol reduced the activated microglia and inflammatory cytokines. Moreover, we evaluated the effects of cycloastragenol against mitochondrial apoptosis and memory dysfunctions in the experimental groups. The findings showed significant regulatory effects against apoptosis and memory dysfunction as revealed by the Morris water maze (MWM) test. Collectively, the findings suggested that cycloastragenol regulates oxidative stress, neurotrophic processes, neuroinflammation, apoptotic cell death, and memory impairment in the mouse model of AD.

Deciphering the Potential Neuroprotective Effects of Luteolin against Aβ1-42-Induced Alzheimer's Disease

The current study was undertaken to unveil the protective effects of Luteolin, a natural flavonoid, against amyloid-beta (Aβ₁–₄₂)-induced neuroinflammation, amyloidogenesis, and synaptic dysfunction in mice. For the development of an AD mouse model, amyloid-beta (Aβ₁–₄₂, 5 μL/5 min/mouse) oligomers were injected intracerebroventricularly (i.c.v.) into mice’s brain by using a stereotaxic frame. After that, the mice were treated with Luteolin for two weeks at a dose of 80 mg/kg/day. To monitor the biochemical changes, we conducted western blotting and immunofluorescence analysis. According to our findings, the infusion of amyloid-beta activated c-Jun N-terminal kinases (p-JNK), p38 mitogen-activated protein kinases, glial fibrillary acidic protein (GFAP), and ionized calcium adaptor molecule 1 (Iba-1) in the cortex and hippocampus of the experimental mice; these changes were significantly inhibited in Aβ₁–₄₂ + Luteolin-treated mice. Likewise, we also checked the expression of inflammatory markers, such as p-nuclear factor-kB p65 (p-NF-kB p65 (Ser536), tissue necrosis factor (TNF-α), and Interleukin1-β (IL-1β), in Aβ₁–₄₂-injected mice brain, which was attenuated in Aβ₁–₄₂ + Luteolin-treated mice brains. Further, we investigated the expression of pro- and anti-apoptotic cell death markers such as Bax, Bcl-2, Caspase-3, and Cox-2, which was significantly reduced in Aβ₁–₄₂ + Lut-treated mice brains compared to the brains of the Aβ-injected group. The results also indicated that with the administration of Aβ₁–₄₂, the expression levels of β-site amyloid precursor protein cleaving enzyme (BACE-1) and amyloid-beta (Aβ₁–₄₂) were significantly enhanced, while they were reduced in Aβ₁–₄₂ + Luteolin-treated mice. We also checked the expression of synaptic markers such as PSD-95 and SNAP-25, which was significantly enhanced in Aβ₁–₄₂ + Lut-treated mice. To unveil the underlying factors responsible for the protective effects of Luteolin against AD, we used a specific JNK inhibitor, which suggested that Luteolin reduced Aβ-associated neuroinflammation and neurodegeneration via inhibition of JNK. Collectively, our results indicate that Luteolin could serve as a novel therapeutic agent against AD-like pathological changes in mice.

The Potential Role of Polyphenols in Oxidative Stress and Inflammation Induced by Gut Microbiota in Alzheimer's Disease

Gut microbiota (GM) play a role in the metabolic health, gut eubiosis, nutrition, and physiology of humans. They are also involved in the regulation of inflammation, oxidative stress, immune responses, central and peripheral neurotransmission. Aging and unhealthy dietary patterns, along with oxidative and inflammatory responses due to gut dysbiosis, can lead to the pathogenesis of neurodegenerative diseases, especially Alzheimer's disease (AD). Although the exact mechanism between AD and GM dysbiosis is still unknown, recent studies claim that secretions from the gut can enhance hallmarks of AD by disturbing the intestinal permeability and blood-brain barrier via the microbiota-gut-brain axis. Dietary polyphenols are the secondary metabolites of plants that possess anti-oxidative and anti-inflammatory properties and can ameliorate gut dysbiosis by enhancing the abundance of beneficial bacteria. Thus, modulation of gut by polyphenols can prevent and treat AD and other neurodegenerative diseases. This review summarizes the role of oxidative stress, inflammation, and GM in AD. Further, it provides an overview on the ability of polyphenols to modulate gut dysbiosis, oxidative stress, and inflammation against AD.

Antioxidative and Anti-inflammatory Effects of Kojic Acid in Aβ-Induced Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a common cause of dementia that is clinically characterized by the loss of memory and cognitive functions. Currently, there is no specific cure for the management of AD, although natural compounds are showing promising therapeutic potentials because of their safety and easy availability. Herein, we evaluated the neuroprotective properties of kojic acid (KA) in an AD mouse model. Intracerebroventricular injection (i.c.v) of Aβ_1-42 (5 μL/5 min/mouse) into wild-type adult mice induced AD-like pathological changes in the mouse hippocampus by increasing oxidative stress and neuroinflammation, affecting memory and cognitive functions. Interestingly, oral treatment of kojic acid (50 mg/kg/mouse for 3 weeks) reversed the AD pathology by reducing the expression of amyloid-beta (Aβ) and beta-site amyloid precursor protein cleaving enzyme1 (BACE-1). Moreover, kojic acid reduced oxidative stress by enhancing the expression of nuclear factor erythroid-related factor 2 (Nrf2) and heme oxygenase 1 (HO1). Also, kojic acid reduced the lipid peroxidation and reactive oxygen species in the Aβ + kojic acid co-treated mice brains. Moreover, kojic acid decreased neuroinflammation by inhibiting Toll-like receptor 4, phosphorylated nuclear factor-κB, tumor necrosis factor-alpha, interleukin 1-beta (TLR-4, p-NFκB, TNFα, and IL-1β, respectively), and glial cells. Furthermore, kojic acid enhanced synaptic markers (SNAP-23, SYN, and PSD-95) and memory functions in AD model mice. Additionally, kojic acid treatment also decreased Aβ expression, oxidative stress, and neuroinflammation in vitro in HT-22 mouse hippocampal cells. To the best of our knowledge, this is the first study to show the neuroprotective effects of kojic acid against an AD mouse model. Our findings could serve as a favorable and alternative strategy for the discovery of novel drugs to treat AD-related neurodegenerative conditions.

Role of Polyphenols as Antioxidant Supplementation in Ischemic Stroke

Stroke is the second most common cause of death globally and the leading cause of death in China. The pathogenesis of cerebral ischemia injury is complex, and oxidative stress plays an important role in the fundamental pathologic progression of cerebral damage in ischemic stroke. Previous studies have preliminarily confirmed that oxidative stress should be a potential therapeutic target and antioxidant as a treatment strategy for ischemic stroke. Emerging experimental studies have demonstrated that polyphenols exert the antioxidant potential to play the neuroprotection role after ischemic stroke. This comprehensive review summarizes antioxidant effects of some polyphenols, which have the most inhibition effects on reactive oxygen species generation and oxidative stress after ischemic stroke.

Chloroquine attenuates thymic stromal lymphopoietin production via suppressing caspase-1 signaling in mast cells

Thymic stromal lymphopoietin (TSLP) produced by mast cells is involved in allergic inflammation pathogenesis. Chloroquine (CQ) is known to be an anti-malarial drug; however, additional protective functions of CQ have been discovered. This study aims to clarify an anti-inflammatory effect of CQ through modulating TSLP levels using an in vitro model of phorbol myristate acetate (PMA) + A23187-activated human mast cell line (HMC-1) and an in vivo model of PMA-irritated ear edema. CQ treatment reduced the production and mRNA expression levels of TSLP in activated HMC-1 cells. CQ down-regulated caspase-1 (CASP1), MAPKs, and NF-κB levels enhanced by stimulation with PMA + A23187. Moreover, ear thickness in ear edema was suppressed following CQ treatment. CQ decreased CASP1 and NF-κB levels in the ear tissue. TSLP levels in the ear tissue and serum were reduced following CQ treatment. Collectively, the above findings elucidate that CQ inhibits the pro-inflammatory mechanisms of TSLP via the down-regulation of distinct intracellular signaling cascade in mast cells. Therefore, CQ may have protective roles against TSLP-mediated inflammatory disorders.

Neuroprotective effects of Senkyunolide I against glutamate-induced cells death by attenuating JNK/caspase-3 activation and apoptosis

Glutamate-induced neurotoxicity is one of the most important pathogenic mechanisms in neurological diseases and is widely used as an in vitro model for ischemic stroke. Senkyunolide I (SEI), an active constituent derived from traditional Chinese medicine Ligusticum chuanxiong Hort. and Angelica sinensis (Oliv.) Diels, has been shown to have beneficial effects against focal cerebral ischemia-reperfusion in rats. However, the mechanisms underlying SEI-mediated neuroprotection remain not well understood. Thus, we explored the influence of SEI in glutamate-mediated injury to mouse neuroblastoma (Neuro2a) cells and determined the mechanisms involved. Neuro2a cells were treated with SEI under exposure to glutamate for 24 h. Cell viability was assessed by using WST-1 reagents, and apoptosis was evaluated using Annexin V-FITC and a PI double staining kit. The protein expression levels of p-AKT, AKT, p-GSK3β, GSK3β, p-p38, p38, p-ERK, ERK, p-JNK, JNK, Bcl-2, Bax, Bcl-xl, p-Bad, Bad, p53, and cleaved caspase-3 were determined by Western blot analysis. Glutamate significantly decreased cell viability and elevated the level of apoptosis. Treatment with SEI reversed those effects. Furthermore, the expression of p-JNK/JNK and cleaved caspase-3 were also reduced after treatment with SEI. Our findings demonstrate that SEI protected Neuro2a cells against glutamate toxicity by regulating JNK/caspase-3 pathway and apoptosis. Thus, SEI maybe a promising candidate for neuroprotection.

Interleukin-22 Plays a Protective Role by Regulating the JAK2-STAT3 Pathway to Improve Inflammation, Oxidative Stress, and Neuronal Apoptosis following Cerebral Ischemia-Reperfusion Injury

The interleukins (ILs) are a pluripotent cytokine family that have been reported to regulate ischemic stroke and cerebral ischemia/reperfusion (I/R) injury. IL-22 is a member of the IL-10 superfamily and plays important roles in tissue injury and repair. However, the effects of IL-22 on ischemic stroke and cerebral I/R injury remain unclear. In the current study, we provided direct evidence that IL-22 treatment decreased infarct size, neurological deficits, and brain water content in mice subjected to cerebral I/R injury. IL-22 treatment remarkably reduced the expression of inflammatory cytokines, including IL-1β, monocyte chemotactic protein- (MCP-) 1, and tumor necrosis factor- (TNF-) α, both in serum and the ischemic cerebral cortex. In addition, IL-22 treatment also decreased oxidative stress and neuronal apoptosis in mice after cerebral I/R injury. Moreover, IL-22 treatment significantly increased Janus tyrosine kinase (JAK) 2 and signal transducer and activator of transcription (STAT) 3 phosphorylation levels in mice and PC12 cells, and STAT3 knockdown abolished the IL-22-mediated neuroprotective function. These findings suggest that IL-22 might be exploited as a potential therapeutic agent for ischemic stroke and cerebral I/R injury.

Palmatine Protects against Cerebral Ischemia/Reperfusion Injury by Activation of the AMPK/Nrf2 Pathway

Palmatine (PAL), a natural isoquinoline alkaloid, possesses extensive biological and pharmaceutical activities, including antioxidative stress, anti-inflammatory, antitumor, neuroprotective, and gastroprotective activities. However, it is unknown whether PAL has a protective effect against ischemic stroke and cerebral ischemia/reperfusion (I/R) injury. In the present study, a transient middle cerebral artery occlusion (MCAO) mouse model was used to mimic ischemic stroke and cerebral I/R injury in mice. Our study demonstrated that PAL treatment ameliorated cerebral I/R injury by decreasing infarct volume, neurological scores, and brain water content. PAL administration attenuated oxidative stress, the inflammatory response, and neuronal apoptosis in mice after cerebral I/R injury. In addition, PAL treatment also decreases hypoxia and reperfusion- (H/R-) induced neuronal injury by reducing oxidative stress, the inflammatory response, and neuronal apoptosis. Moreover, the neuroprotective effects of PAL were associated with the activation of the AMP-activated protein kinase (AMPK)/nuclear factor E2-related factor 2 (Nrf2) pathway, and Nrf2 knockdown offsets PAL-mediated antioxidative stress and anti-inflammatory effects. Therefore, our results suggest that PAL may be a novel treatment strategy for ischemic stroke and cerebral I/R injury.