Diosmin protects against cerebral ischemia/reperfusion injury through activating JAK2/STAT3 signal pathway in mice

Mitigating Bisphenol-Induced Neurotoxicity: Exploring the Therapeutic Potential of Diosmin in Zebrafish Larvae

Neurological disorders are commonly accompanied by inflammation of the brain, which can be triggered by oxidative stress and cell damage caused by hazardous environmental substances. The ubiquitous harmful chemical bisphenol A (BPA) has been linked to several neuropsychiatric disorders and is thought to contribute to oxidative damage. This study explored the mechanisms underlying the effects of BPA on neurological health. Diosmin (DM) is a natural flavonoid (C28H32O15) found in various plants, including citrus fruits and it possess various pharmacological activities. This study investigated the neuroprotective effects of DM on BPA-induced neuroinflammation in zebrafish larvae, suggesting its potential therapeutic uses. Developmental toxicity, including mortality, hatching rate, and heart rate, was evaluated to determine DM toxicity. Oxidative stress biomarkers such as reactive oxygen species (ROS), superoxide anions (O-2), lipid peroxidation (LPO), and nitric oxide (NO) were quantified using colorimetric assays in the head region of the larvae. Antioxidant enzyme activities were measured to assess the impact of DM on antioxidant defences. Neuroinflammation was evaluated by analysing pro-inflammatory markers using RT-qPCR, and motor neuron function was assessed using acetylcholinesterase (AChE) activity and behavioural assays. The findings indicate that exposure to DM prevents neurotoxicity induced by BPA by increasing antioxidant defence enzymes and reducing the levels of ROS, O2-, LPO, and NO in the head region of zebrafish larvae. Furthermore, DM enhanced motor neuron function by increasing AChE activity and decreasing neuroinflammation by reducing the levels of pro-inflammatory markers influenced by BPA. This study suggests that DM offers neuroprotection against BPA-induced oxidative damage and neuroinflammation, thereby paving the way for the development of new treatment options for neurological disorders.

Behavioral deficits after traumatic brain injury: Neuroprotective effect of Diosmin

Following traumatic brain injury (TBI), the progression of brain tissue injuries and subsequent psychiatric complications considerably affect the quality of life in humans. Diosmin (DM) is a flavonoid and has been demonstrated to improve cognitive deficit and amplify brain electrical activity in the rat model of traumatic brain injury. We aimed to explore the potential protective effects of DM on single-unit neuronal firing, as well as on motor function and behaviors related to depression and anxiety associated with TBI. Forty-eight Wistar rats were randomly divided into sham-operated, TBI, and TBI + DM (100 mg/kg/day; P.O.) Groups. Depression and anxiety-like behaviors and motor function were evaluated through standard behavioral tests and Rotarod apparatus at scheduled points in time. We also measured the neuronal firing rate in the striatum. The results indicated that DM pretreatment significantly improved TBI-induced depression and anxiety-like behaviors (P < 0.01), and motor coordination (P < 0.05). The striatum neuronal firing rate in the TBI + DM Group was significantly higher than the TBI group (216 Vs 49.38 Hz, P < 0.001). The findings suggest that pretreatment with DM may offer protective benefits against TBI-associated behavioral deficits.

Neuroprotective potential of hispidulin and diosmin: a review of molecular mechanisms

Flavonoids are an important class of natural products, particularly, belong to a class of plant secondary metabolites having a polyphenolic structure. They are widely found in fruits, vegetables, and certain beverages. Hispidulin and diosmin are naturally occurring flavonoids recognized for their potential health benefits, such as antioxidant, anti-inflammatory, and neuroprotective properties. Hispidulin is present in several plants, including Arnica montana, Salvia officinalis (sage), and Eupatorium arnottianum. Diosmin is mainly extracted from citrus fruits like lemons and oranges and can also be synthesized from hesperidin, another flavonoid found in citrus fruits. Neurodegenerative diseases are characterized by complex signaling pathways that contribute to neuronal deterioration. The JAK/STAT pathway is involved in inflammatory responses, while the NF-κB/NLRP3 pathway is associated with metabolic stress and inflammation, both facilitating neurodegeneration. Conversely, the AMPK/pGSK3β pathway is crucial for neuroprotection, regulating cellular responses to oxidative stress and promoting neuronal survival. Additionally, the BACE/Aβ pathway exacerbates neuronal damage by triggering inflammatory and oxidative stress responses, highlighting critical targets for therapeutic strategies. Hispidulin and diosmin have emerged as promising agents in the modulation of mediators involved in neuroinflammation and neurodegenerative diseases. Oxidative stress and inflammatory pathways, including those driven by Aβ/BACE1 and JAK/STAT signaling, are central to neuronal damage and disease progression. Recent studies highlight that hispidulin and diosmin exhibit notable neuroprotective effects by targeting these mediators. Hispidulin has been shown to impact key inflammatory cytokines and adhesion molecules, while diosmin influences proinflammatory cytokine production and inflammasome activation. Both compounds offer potential therapeutic benefits by modulating crucial mediators linked to neuroinflammation and neurodegeneration. This review article is designed to explore the intricate mechanistic interplay underlying the neuroprotective effects of hispidulin and diosmin.

Diosmin alleviates NLRP3 inflammasome-dependent cellular pyroptosis after stroke through RSK2/CREB pathway

In the context of our previous analyses on the main active ingredients of Jieyudan, a classic formula targeting aphasia in stroke, we further delve into the function and mechanisms of its active ingredient, Diosmin (DM), which may exert neuroprotective effects, in ischemic stroke. Herein, bioinformatics analysis revealed targets of DM and their intersection with differentially expressed genes in ischemic stroke. Middle cerebral artery occlusion (MCAO) rats and oxygen-glucose deprivation (OGD) cells were used to construct in vivo and in vitro models of ischemic stroke. The effects of DM on MCAO rats were assessed by Zea-Longa score, Morris water maze, TTC staining, Nissl staining, immunohistochemistry, and Western blot. At the cellular level, cell counting kit-8 assay and Western blot were carried out to verify the mechanism of DM in ischemic stroke. In vivo, DM decreased neurological deficit score, cerebral infarct volume and neuronal damage, and improved cognitive function in MCAO rats. In vitro, DM increased the viability of OGD-treated cells. In addition, DM down-regulated the expressions of NLR family pyrin domain containing 3 (NLRP3) and pyroptosis-associated proteins, while up-regulating ribosomal protein S6 kinase A3 (RSK2) level and activating cyclic-AMP response element-binding protein (CREB) signaling. Conversely, RSK2 inhibitor LJH685 reduced the viability and promoted pyroptosis-associated protein levels, which also partially reversed the effects of DM in vitro. Collectively, DM plays a therapeutic role in ischemic stroke by inhibiting NLRP3 inflammasome-mediated cellular pyroptosis via the RSK2/CREB pathway.

Diosmin: A promising phytochemical for functional foods, nutraceuticals and cancer therapy

Diosmin, a potent bioflavonoid derived from citrus fruits, has gained significant attention for its anticancer potential, reflecting a critical need in the ongoing battle against cancer. Amidst increasing cancer incidence, the quest for safer and more effective treatments has brought diosmin to the forefront, given its unique pharmacological profile distinct from other flavonoids. Diosmin's anticancer mechanisms are multifaceted, involving apoptosis induction, angiogenesis inhibition, and metastasis prevention. Extensive research encompassing cellular studies, animal models, and limited clinical trials underscores its efficacy not only against cancer but also in managing chronic venous insufficiency and hemorrhoids, attributing to its anti-inflammatory properties. Furthermore, diosmin exhibits low toxicity and complements conventional chemotherapy, proposing its utility as an adjunct therapy in cancer treatment protocols. The review delves into the specific anticancer advantages of diosmin, distinguishing it from the broader flavonoid category. It provides a detailed analysis of its implications in preclinical and clinical settings, advocating for its consideration in the oncological therapeutic arsenal. By juxtaposing diosmin with other herbal medicines, the review offers a nuanced perspective on its role within the wider context of natural anticancer agents, emphasizing the need for further clinical research to substantiate its efficacy and safety in oncology.

The impact of cytokines in neuroinflammation-mediated stroke

Cerebral stroke is ranked as the third most common contributor to global mortality and disability. The involvement of inflammatory mechanisms, both peripherally and within the CNS, holds significance in the pathophysiological cascades following the initiation of stroke. After the onset of acute stroke, predominantly ischemic, a subsequent phase of neuroinflammation ensues. It is a dual-effect process that not only exacerbates injury, leading to cell death, but paradoxically, it also serves a shielding role in facilitating recovery. Cytokines serve as pivotal mediators within the inflammatory cascade, actively contributing to the progression of ischemic damage. Stroke is followed by increased expression of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, etc. leading to the recruitment and stimulation of glial cells and peripheral leukocytes at the site of injury, promoting neuroinflammation. Cytokines can directly induce neuronal injury and death through various mechanisms, including excitotoxicity, oxidative stress, HPA-axis activation, secretion of matrix metalloproteinase and apoptosis. They can also amplify the inflammatory response, leading to further neuronal damage. Therapeutic strategies aimed at modulating cytokine release, immune response and cytokine signalling or activity are being explored as potential interventions to mitigate neuroinflammation and its detrimental effects in stroke. In this review, we have given a concise summary of our current knowledge of the function of various cytokines, brain inflammation and various signalling and molecular pathways including JAK/STAT3, TGF-β/Smad, MAPK, HMGB1/TLR and NF-κB modulated cytokines regulation in stroke. Therapeutic agents such as MCC950, genistein, edaravone, minocycline, etc. targeting various cytokines-associated signalling pathways have shown efficacy in preclinical and clinical trials reducing the pathophysiology of the illness were also addressed in this study.

Depression-reminiscent Behavior Induced by Chronic Unpredictable Mild Stress Paradigm in Mice Substantially Abrogated by Diosmin

Background:

Diosmin has already been described and documented to be neuroprotective, antioxidant and anti-inflammatory. It may possess or hold depressionalleviating activity. Therefore, the purpose of the current research protocol is to investigate the depression-relieving proficiency of diosmin in stressed and unstressed mice.

Methods:

Male mice (Swiss albino) were imperiled to an unpredictable chronic stress paradigm every day for three sequential weeks, and depression-resembling behavioral despair was induced. Imipramine 15 mg/kg and diosmin (25, 50 and 100 mg/kg) were dispensed for 21 successive days to discrete groups of stressed and unstressed mice.

Results:

Both diosmin (100 mg/kg) and 15 mg/kg imipramine administration for 3 consecutive weeks substantially or significantly diminished the immobility period of mice imperiled to stress in comparison to stressed mice gauzed with the vehicle. Diosmin (25, 50 and 100 mg/kg) and imipramine considerably reinstated the diminished sucrose proclivity (sucrose preference percentage; %) in stressed mice, demonstrating their considerable or substantial depression-relieving effects. The locomotor activities of mice were not considerably altered by these drugs. Antidepressant-like activity of diosmin for immobility periods and preference for sucrose was observed to be analogous to imipramine. Diosmin (100 mg/kg) and imipramine substantially quashed CUMS- persuaded escalation of plasma corticosterone and nitrite levels, malondialdehyde levels and MAO-A activity in the brain of stressed mice. Both drugs also substantially reversed CUMS-prompted reduction in catalase activity and brain glutathione levels.

Conclusion:

Accordingly, diosmin revealed significant anti-depressive activity in mice imperiled to chronic mild unpredictable stress paradigm conceivably via mitigation of nitrosative and oxidative stress, reticence of brain MAO-A action, and sink drop of plasma corticosterone degrees.

Effect of scutellarin on BV-2 microglial-mediated apoptosis in PC12 cells via JAK2/STAT3 signalling pathway

Previous studies have shown that scutellarin inhibits the excessive activation of microglia, reduces neuronal apoptosis, and exerts neuroprotective effects. However, whether scutellarin regulates activated microglia-mediated neuronal apoptosis and its mechanisms remains unclear. This study aimed to investigate whether scutellarin can attenuate PC12 cell apoptosis induced by activated microglia via the JAK2/STAT3 signalling pathway. Microglia were cultured in oxygen-glucose deprivation (OGD) medium, which acted as a conditioning medium (CM) to activate PC12 cells, to investigate the expression of apoptosis and JAK2/STAT3 signalling-related proteins. We observed that PC12 cells apoptosis in CM was significantly increased, the expression and fluorescence intensity of the pro-apoptotic protein Bax and apoptosis-related protein cleaved caspase-3 were increased, and expression of the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2) was decreased. Phosphorylation levels and fluorescence intensity of the JAK2/STAT3 signalling pathway-related proteins JAK2 and STAT3 decreased. After treatment with scutellarin, PC12 cells apoptosis as well as cleaved caspase-3 and Bax protein expression and fluorescence intensity decreased. The expression and fluorescence intensity of Bcl-2, phosphorylated JAK2, and STAT3 increased. AG490, a specific inhibitor of the JAK2/STAT3 signalling pathway, was used. Our findings suggest that AG490 attenuates the effects of scutellarin. Our study revealed that scutellarin inhibited OGD-activated microglia-mediated PC12 cells apoptosis which was regulated via the JAK2/STAT3 signalling pathway.

JAK2/STAT3 as a new potential target to manage neurodegenerative diseases: An interactive review

Neurodegenerative diseases (NDDs) are a collection of incapacitating disorders in which neuroinflammation and neuronal apoptosis are major pathological consequences due to oxidative stress. Neuroinflammation manifests in the impacted cerebral areas as a result of pro-inflammatory cytokines stimulating the Janus Kinase2 (JAK2)/Signal Transducers and Activators of Transcription3 (STAT3) pathway via neuronal cells. The pro-inflammatory cytokines bind to their respective receptor in the neuronal cells and allow activation of JAK2. Activated JAK2 phosphorylates tyrosines on the intracellular domains of the receptor which recruit the STAT3 transcription factor. The neuroinflammation issues are exacerbated by the active JAK2/STAT3 signaling pathway in conjunction with additional transcription factors like nuclear factor kappa B (NF-κB), and the mammalian target of rapamycin (mTOR). Neuronal apoptosis is a natural process made worse by persistent neuroinflammation and immunological responses via caspase-3 activation. The dysregulation of micro-RNA (miR) expression has been observed in the consequences of neuroinflammation and neuronal apoptosis. Neuroinflammation and neuronal apoptosis-associated gene amplification may be caused by dysregulated miR-mediated aberrant phosphorylation of JAK2/STAT3 signaling pathway components. Therefore, JAK2/STAT3 is an attractive therapeutic target for NDDs. Numerous synthetic and natural small molecules as JAK2/STAT3 inhibitors have therapeutic advances against a wide range of diseases, and many are now in human clinical studies. This review explored the interactive role of the JAK2/STAT3 signaling system with key pathological factors during the reinforcement of NDDs. Also, the clinical trial data provides reasoning evidence about the possible use of JAK2/STAT3 inhibitors to abate neuroinflammation and neuronal apoptosis in NDDs.

Novel insight into the therapeutical potential of flavonoids from traditional Chinese medicine against cerebral ischemia/reperfusion injury

Cerebral ischemia/reperfusion injury (CIRI) is a major contributor to poor prognosis of ischemic stroke. Flavonoids are a broad family of plant polyphenols which are abundant in traditional Chinese medicine (TCM) and have beneficial effects on several diseases including ischemic stroke. Accumulating studies have indicated that flavonoids derived from herbal TCM are effective in alleviating CIRI after ischemic stroke in vitro or in vivo, and exhibit favourable therapeutical potential. Herein, we systematically review the classification, metabolic absorption, neuroprotective efficacy, and mechanisms of TCM flavonoids against CIRI. The literature suggest that flavonoids exert potential medicinal functions including suppressing excitotoxicity, Ca2+ overloading, oxidative stress, inflammation, thrombin's cellular toxicity, different types of programmed cell deaths, and protecting the blood-brain barrier, as well as promoting neurogenesis in the recovery stage following ischemic stroke. Furthermore, we identified certain matters that should be taken into account in future research, as well as proposed difficulties and opportunities in transforming TCM-derived flavonoids into medications or functional foods for the treatment or prevention of CIRI. Overall, in this review we aim to provide novel ideas for the identification of new prospective medication candidates for the therapeutic strategy against ischemic stroke.

IL-22 relieves hepatic ischemia-reperfusion injury by inhibiting mitochondrial apoptosis based on the activation of STAT3

INTRODUCTION

Interleukin-22 (IL-22) has been proven to exhibit a protective role in hepatic ischemia-reperfusion injury (HIRI). This study aimed to explore the change of IL-22 and IL-22 receptor 1 (IL-22R1) axis in HIRI and its role in mitochondrial apoptosis associated with STAT3 activation.

MATERIALS AND METHODS

I/R mice were examined for the expression of IL-22, IL-22R1 and IL-22BP. The roles of IL-22 in hepatic histopathology and oxidative stress injuries (ALT, MDA and SOD) were determined. Oxidative stress damages of AML-12 cells were induced by H2O2, and were indicated by apoptosis, Ca2+ concentration, and mitochondrial function. The effects of IL-22 on p-STAT3Try705 were analyzed.

RESULTS

We found that the expression of IL-22, IL-22R1, and IL-22BP was elevated 24 h after I/R induction, while decreased 48 h after I/R induction. Furthermore, we also discovered that IL-22 rescued the morphological damages and dysfunction of hepatocytes induced by H2O2, which were antagonized by IL-22BP, an endogenous antagonist of IL-22. Additionally, increased levels of Ca2+ concentration, MDA, ROS, apoptosis and mitochondrial dysfunction were noticed in H2O2-treated hepatocytes. However, IL-22 ameliorated the effects of I/R or H2O2. The protective effects of IL-22 were reversed by AG490, a specific antagonist of STAT3.

CONCLUSIONS

In conclusion, our results indicated that IL-22 inhibited I/R-induced oxidative stress injury, Ca2+ overload, and mitochondrial apoptosis via STAT3 activation.

Enriched environment promotes post-stroke angiogenesis through astrocytic interleukin-17A

Objective

Our previous studies have revealed that the protective effect of an enriched environment (EE) may be linked with astrocyte proliferation and angiogenesis. However, the relationship between astrocytes and angiogenesis under EE conditions still requires further study. The current research examined the neuroprotective effects of EE on angiogenesis in an astrocytic interleukin-17A (IL-17A)-dependent manner following cerebral ischemia/reperfusion (I/R) injury.

Methods

A rat model of ischemic stroke based on middle cerebral artery occlusion (MCAO) for 120 min followed by reperfusion was established, after which rats were housed in either EE or standard conditions. A set of behavior tests were conducted, including the modified neurological severity scores (mNSS) and the rotarod test. The infarct volume was evaluated by means of 2,3,5-Triphenyl tetrazolium chloride (TTC) staining. To evaluate the levels of angiogenesis, the protein levels of CD34 were examined by means of immunofluorescence and western blotting, while the protein and mRNA levels of IL-17A, vascular endothelial growth factor (VEGF), and the angiogenesis-associated factors interleukin-6 (IL-6), JAK2, and STAT3 were detected by western blotting and real-time quantitative PCR (RT-qPCR).

Results

We found that EE promoted functional recovery, reduced infarct volume, and enhanced angiogenesis compared to rats in standard conditions. IL-17A expression in astrocytes was also increased in EE rats. EE treatment increased the levels of microvascular density (MVD) and promoted the expression of CD34, VEGF, IL-6, JAK2, and STAT3 in the penumbra, while the intracerebroventricular injection of the IL-17A-neutralizing antibody in EE rats attenuated EE-mediated functional recovery and angiogenesis.

Conclusion

Our findings revealed a possible neuroprotective mechanism of astrocytic IL-17A in EE-mediated angiogenesis and functional recovery after I/R injury, which might provide the theoretical basis for EE in clinical practise for stroke patients and open up new ideas for the research on the neural repair mechanism mediated by IL-17A in the recovery phase of stroke.

Chrysophanol facilitates long-term neurological recovery through limiting microglia-mediated neuroinflammation after ischemic stroke in mice

BACKGROUND

Inflammation plays an important role in ischemic brain injury and affects brain recovery and neuroplasticity. Chrysophanol (CHR), has attracted attention for its protective effects through immunomodulatory and anti-inflammatory properties. However, the effect of CHR for brain recovery and neuroplasticity is not clear. The current study aimed to investigate the effect of CHR in the chronic phase of stroke in mice, and to elucidate the underlying mechanisms.

METHODS

C57BL/6 mice were subjected to treatment with Vehicle or CHR immediately through intraperitoneal injection daily for 14 d after distal middle cerebral artery occlusion (dMCAO). Neurological deficits were monitored up to 28 days after stroke. Nissl and Golgi stain, neural plasticity, and microglia-associated inflammatory cytokines were detected. Primary cortical neuron and BV2 microglia cell lines were employed to explore the underlying mechanism in vitro.

RESULTS

Compared with Vehicle group, CHR mitigated the histological damage, facilitated the neural plasticity and improved the neurological function up to 4 weeks after stroke. In vitro, CHR promoted the complexity of neurons and the spine density by modulating microglial polarization and reducing the expression of microglia-associated inflammatory cytokines, especially IL-6. In vivo, microglia activation and inflammatory cytokines were significantly increased after dMCAO and downregulated by CHR. Further investigation showed STAT3 is the major downstream effector of IL-6 signaling.

CONCLUSIONS

CHR ameliorated microenvironment for neural plasticity and exhibited neuroprotection via arresting microglia toward pro-inflammatory phenotype and downregulation of the expressions of pro-inflammatory cytokines, especially of IL-6. IL-6-STAT3 signaling might be CHR's therapeutic target for neuroinflammatory responses after stroke.

Purpurogallin improves neurological functions of cerebral ischemia and reperfusion mice by inhibiting endoplasmic reticulum stress and neuroinflammation

BACKGROUND

Purpurogallin (PPG) has been testified to have neuroprotective effects. This study intends to probe the neuroprotection of PPG on cerebral ischemia/reperfusion (I/R) injury and its potential mechanism.

METHODS

C57/B6 mice, BV2 microglia and HT22 hippocampal neurons were used for in-vivo and in-vitro experiments. I/R injury models were constructed using middle cerebral artery occlusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R), respectively. The expression of apoptosis and inflammatory proteins, and endoplasmic reticulum (ER) stress proteins were gauged by Western blotting (WB). The contents of inflammatory cytokines in OGD/R-induced BV2 microglia were testified by enzyme-linked immunosorbent assay (ELISA). Cell counting kit-8 (CCK-8), TUNEL assay and flow cytometry (FCM) were utilized to examine the viability and apoptosis of cells. The neurological, learning and memory functions were evaluated by the modified neurological severity score (mNSS) and water maze experiment. 2, 3, 5-triphenyltetrazole chloride (TTC) staining was utilized to calculate the volume of cerebral infarction and cerebral edema in the peri-infarct area. Apoptosis-related proteins, inflammation-related proteins and ER stress proteins were gauged by WB. ELISA was conducted to verify inflammatory cytokines.

RESULTS

PPG treatment notably abated the expression of ER stress proteins and inflammatory factors in OGD/R-induced BV2 microglia and boosted HT22 neuron's viability and eased their apoptosis in comparison to the control group. In vivo, PPG treatment signally lessened cerebral infarct area, cerebral edema, and neurological deficit scores in MCAO/R mice. Additionally, PPG caused a dramatic decline in neuronal apoptosis and levels of ER stress proteins and inflammatory factors in the brain's peri-infarct region of MCAO/R mice. Mechanically, PPG blocked the TLR4/NF-κB pathway in OGD/R-induced BV2, HT22 neurons, and the MCAO/R mice.

CONCLUSION

PPG attenuates brain I/R damage probably by suppressing ER stress and neuroinflammation via inactivation of the TLR4/NF-κB pathway, suggesting that PPG may be a candidate drug for treating cerebral I/R injury.

The potential neuroprotective effect of diosmin in rotenone-induced model of Parkinson's disease in rats

Most treatments for Parkinson's disease (PD) focus on improving the symptoms and the dopaminergic effects; nevertheless, they cannot delay the disease progression. Diosmin (DM), a naturally occurring flavone that is obtained from citrus fruits, has demonstrated anti-apoptotic, anti-inflammatory and antioxidative properties in many diseases. This study aimed to assess the neuroprotective effects of diosmin in rotenone-induced rat model of PD and investigate its potential underlying mechanisms. A preliminary dose-response study was conducted where rats were treated with DM (50,100 and 200 mg/kg, p.o.) concomitantly with rotenone (2 mg/kg, s.c.) for 4 weeks. Catalepsy, motor impairment, spontaneous locomotion, body weight, histological examination and tyrosine hydroxylase (TH) immunoreactivity were evaluated in both the midbrains and striata of rats. Treatment with DM (200 mg/kg) showed the most promising outcome therefore, it was selected for further evaluation of α-synuclein, Bax, Bcl2, nuclear factor kappa B (NF-кB), nuclear factor erythroid 2- related factor 2 (Nrf2), and heme oxygenase-1 (HO-1), in addition to biochemical analysis of tumor necrosis factor-α (TNF-α). Results showed that DM (200 mg/kg, p.o.) prevented rotenone-induced motor impairment, weight reduction and histological damage. Furthermore, it significantly inhibited rotenone-induced decrease in TH expression. These results were correlated with reduction in α-synuclein immunoreactivity, together with improvement of Bax/Bcl2 ratio compared to rotenone group. DM also attenuated rotenone-induced increase in NF-кB expression as well as TNF- α levels. Moreover, DM inhibited rotenone-induced upregulation of Nrf2/HO-1 pathway. Thus, the current study suggests that DM might be a promising candidate for managing the neuropathological course of PD.

Tricin attenuates cerebral ischemia/reperfusion injury through inhibiting nerve cell autophagy, apoptosis and inflammation by regulating the PI3K/Akt pathway

To elucidate the effect of tricin in cerebral ischemia/reperfusion (I/R) injury and examine its possible underlying mechanisms. Rats were randomly divided into Sham (exposed the right internal carotid arteries), I/R, and tricin (administered at various doses) groups. After the cerebral I/R injury model was established, a Morris water maze test and a tetrazolium chloride assay were performed. Apoptosis and autophagy were assessed in the nerve cells of hippocampus tissue, and the levels of inflammatory markers within animal serum were detected. Proteins related to apoptosis and the PI3K/Akt pathway were evaluated. To further investigate the mechanisms by which tricin affects brain damage, mouse neuroblastoma cells N2a were divided into control, oxygen-glucose deprivation and reoxygenation (OGD/R), tricin, PI3K/Akt activator, and tricin + PI3K/Akt inhibitor groups. The cell viability, apoptosis, inflammatory factors, and PI3K/Akt pathway related proteins in N2a cells were also detected. The results revealed that I/R-induced learning and memory dysfunction was improved by tricin treatment. The area of cerebral infarction, the levels of apoptosis and autophagy in nerve cells, and the serum inflammatory marker content were all decreased following tricin treatment. Additionally, the expression of Beclin-1 protein was downregulated, while the expression of Bcl-2 protein, p-PI3K/PI3K and p-Akt/Akt was upregulated after tricin treatment. Mechanistically, tricin or PI3K/Akt activator ameliorated OGD/R-induced apoptosis, autophagy, and inflammation. However, these effects were reversed following PI3K/Akt inhibitor treatment in OGD/R-induced N2a cells. In summary, this study suggested that tricin can against I/R-induced brain injury by inhibiting autophagy, apoptosis and inflammation, and activating the PI3K/Akt signaling pathway.

Protective role of lidocaine against cerebral ischemia-reperfusion injury: An in vitro study

Lidocaine, a local anesthetic, is a valuable agent for the treatment of neuronal ischemia/reperfusion (I/R) injury. The aim of the present study was to investigate the role of lidocaine in oxygen-glucose deprivation/reperfusion (OGD/R)-induced cortical neurons and explore the related molecular mechanisms. Cerebral cortical neurons were isolated from Sprague-Dawley rat embryos and stimulated with OGD/R to establish an in vitro I/R injury model. Subsequently, neuronal cell viability, cytotoxicity and apoptosis were evaluated by performing the MTT assay, lactate dehydrogenase (LDH) assay and flow cytometry, respectively. The results suggested that OGD/R exposure significantly decreased cerebral cortical neuron cell viability, accelerated LDH release and induced cell apoptosis compared with control neurons, indicating that cerebral I/R injury was stimulated by OGD/R treatment. Further investigation indicated that 10 µM lidocaine significantly enhanced neuronal cell viability, and reduced LDH release and neuronal cell apoptosis in OGD/R-exposed cells compared with the OGD/R + saline group, which indicated that lidocaine displayed neuroprotective effects against I/R damage. In addition, the findings of the present study suggested that OGD/R exposure significantly decreased Bcl-2 and Bcl-xl protein expression levels, but increased Bax protein expression levels, the Bax/Bcl-2 ratio and caspase-3 activity compared with control neurons. However, lidocaine reversed OGD/R-mediated alterations to apoptosis-related protein expression. Furthermore, the results of the present study indicated that lidocaine increased Wnt3a, β-catenin and cyclin D1 expression levels in OGD/R-exposed cells compared with the OGD/R + saline group, thus activating the Wnt/β-catenin signaling pathway. The findings of the present study suggested that lidocaine served a protective role in OGD/R-triggered neuronal damage by activating the Wnt/β-catenin signaling pathway; therefore, lidocaine may serve as a potential candidate for the treatment of cerebral I/R injury.

Diosmin Inhibits Glioblastoma Growth through Inhibition of Autophagic Flux

Diosmin, a natural flavone glycoside acquired through dehydrogenation of the analogous flavanone glycoside hesperidin, is plentiful in many citrus fruits. Glioblastoma multiforme (GBM) is the most malignant primary brain tumor; the average survival time of GBM patients is less than 18 months after standard treatment. The present study demonstrated that diosmin, which is able to cross the blood-brain barrier, inhibited GBM cell growth in vitro and in vivo. Diosmin also impeded migration and invasion by GBM8401and LN229 GBM cells by suppressing epithelial-mesenchymal transition, as indicated by increased expression of E-cadherin and decreased expression of Snail and Twist. Diosmin also suppressed autophagic flux, as indicated by increased expression of LC3-II and p62, and induced cell cycle arrest at G1 phase. Importantly, diosmin did not exert serious cytotoxic effects toward control SVG-p12 astrocytes, though it did reduce astrocyte viability at high concentrations. These findings provide potentially helpful support to the development of new therapies for the treatment of GBM.

Adiponectin alleviated renal cell apoptosis and inflammation via inactivation of JAK2/STAT3 signal pathway in an acute pyelonephritis mouse model

Background

Acute pyelonephritis (APN), an acute and severe kidney infection, is usually treated with antibiotics. However, APN treatment has become increasingly challenging because of bacterial resistance. Adiponectin, an adipokine, has recently been reported to exhibit profound anti-inflammatory and anti-apoptotic effects. However, the effect of adiponectin on the outcomes of APN treatment remains unclear. In this study, we aimed to investigate the effects of adiponectin on APN and the mechanisms underlying these effects.

Methods

Wild-type C57 mice and adiponectin-knockout (KO) mice were divided into 6 groups: the wild-type control group, the wild-type model group, the wild-type adiponectin intervention group, the KO control group, the KO model group, and the adiponectin-KO intervention group. We measured white blood cell (WBC) and neutrophil counts (NC) using a multispecies hematology analyzer; tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) using enzyme-linked immunosorbent assay (ELISA); blood urea nitrogen (BUN) and serum creatinine (SCr) levels using colorimetry; and the protein levels of JAK2, STAT3, p-JAK2, p-STAT3, Bcl-2, and Bax in renal tissues using western blot analysis. Apoptotic cells were detected using the transferase-mediated dUTP nick end labelling (TUNEL) assay.

Results

Compared to the wild-type mice, the KO mice showed a more severe inflammatory response and kidney damage after Escherichia coli infection. After treatment with exogenous adiponectin injection, the inflammatory response, oxidative stress, and kidney damage were partly alleviated. Adiponectin KO led to JAK2/STAT3 signaling activation, and exogenous adiponectin administration inactivated JAK2/STAT3 signaling in the APN model. APN can lead to an increase in the level of the protein Bax and a decrease in the level of the bcl-2 protein, thereby increasing apoptosis; this effect was inhibited by adiponectin.

Conclusions

Through use of a pyelonephritis mouse model, we demonstrated that adiponectin might alleviate renal cell apoptosis and inflammatory response by inactivating the JAK2/STAT3 signaling pathway.

Nose-to-brain delivery of borneol modified tanshinone IIA nanoparticles in prevention of cerebral ischemia/reperfusion injury

Targeted treatment of cerebral ischemia/reperfusion injury (CIRI) remains a problem due to the difficulty in drug delivery across the blood–brain barrier (BBB). In this study, we developed Bo-TSA-NP, a novel tanshinone IIA (TSA) loaded nanoparticles modified by borneol, which has long been proved with the ability to enhance other drugs’ transport across the BBB. The Bo-TSA-NP, with a particle size of about 160 nm, drug loading of 3.6%, showed sustained release and P-glycoprotein (P-gp) inhibition property. It demonstrated a significantly higher uptake by 16HBE cells in vitro through the clathrin/caveolae-mediated endocytosis and micropinocytosis. Following intranasal (IN) administration, Bo-TSA-NP significantly improved the preventive effect on a rat model of CIRI with improved neurological scores, decreased cerebral infarction areas and a reduced content of malondialdehyde (MDA) and increased activity of superoxide dismutase (SOD) in rat brain. In conclusion, these results indicate that Bo-TSA-NP is a promising nose-to-brain delivery system that can enhance the prevention effect of TSA on CIRI.

Neuroprotective Phytochemicals in Experimental Ischemic Stroke: Mechanisms and Potential Clinical Applications

Ischemic stroke is a challenging disease with high mortality and disability rates, causing a great economic and social burden worldwide. During ischemic stroke, ionic imbalance and excitotoxicity, oxidative stress, and inflammation are developed in a relatively certain order, which then activate the cell death pathways directly or indirectly via the promotion of organelle dysfunction. Neuroprotection, a therapy that is aimed at inhibiting this damaging cascade, is therefore an important therapeutic strategy for ischemic stroke. Notably, phytochemicals showed great neuroprotective potential in preclinical research via various strategies including modulation of calcium levels and antiexcitotoxicity, antioxidation, anti-inflammation and BBB protection, mitochondrial protection and antiapoptosis, autophagy/mitophagy regulation, and regulation of neurotrophin release. In this review, we summarize the research works that report the neuroprotective activity of phytochemicals in the past 10 years and discuss the neuroprotective mechanisms and potential clinical applications of 148 phytochemicals that belong to the categories of flavonoids, stilbenoids, other phenols, terpenoids, and alkaloids. Among them, scutellarin, pinocembrin, puerarin, hydroxysafflor yellow A, salvianolic acids, rosmarinic acid, borneol, bilobalide, ginkgolides, ginsenoside Rd, and vinpocetine show great potential in clinical ischemic stroke treatment. This review will serve as a powerful reference for the screening of phytochemicals with potential clinical applications in ischemic stroke or the synthesis of new neuroprotective agents that take phytochemicals as leading compounds.

The bidirectional role of the JAK2/STAT3 signaling pathway and related mechanisms in cerebral ischemia-reperfusion injury

The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway, a well-conserved and basic intracellular signaling cascade, is mostly inactivated under basal conditions, although it can be phosphorylated under extracellular stimulation; in addition, it can influence the transcription and expression of multiple genes involved in biological processes such as cellular growth, metabolism, differentiation, degradation and angiogenesis. The inflammatory response, apoptosis, oxidative stress and angiogenesis are the main factors involved in the pathogenesis of ischemic stroke. Numerous studies have confirmed that the JAK2/STAT3 axis can be activated rapidly by ischemic stress, which is closely related to the regulation of these important pathological processes. However, different opinions on the specific role of this signaling pathway remain. In this paper, we review and summarize previous studies on the JAK2/STAT3 pathway in ischemic stroke.

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.

In silico identification of strong binders of the SARS-CoV-2 receptor-binding domain

The world is currently witnessing the spread of the deadly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the coronavirus disease 2019 (COVID-19). In less than three months since the first cases were reported, the World Health Organization declared it a pandemic disease. Although several treatment and prevention strategies are currently under investigation, a continuous effort to investigate and develop effective cures is urgently needed. Thus, we performed molecular docking and structure-based virtual screening of libraries of approved drugs, antivirals, inhibitors of protein-protein interactions, and one million other small molecules to identify strong binders of the SARS-CoV-2 receptor-binding domain (RBD) that might interfere with the receptor recognition process, so as to inhibit the viral cellular entry. According to our screening and selection criteria, three approved antivirals (elbasvir, grazoprevir, and sovaprevir) and 4 other drugs (hesperidin, pamaqueside, diosmin, and sitogluside) were identified as potent binders of the RBD. The binding of these molecules involved several RBD residues required for the interaction of the virus with its cellular receptor. Furthermore, this study also discussed the pharmacological action of the 4 non-antiviral drugs on hematological and neurological disorders that, in addition to inhibiting the viral entry, could be beneficial against the neurological disorders identified in COVID-19 patients. Besides, six other small-molecules were identified, with no pharmacological description so far, exhibiting strong binding affinities to the RBD that we believe worth being investigated as inhibitors of the SARS-CoV-2-receptor interaction.

Therapeutic potential of diosmin, a citrus flavonoid against arsenic-induced neurotoxicity via suppression of NOX 4 and its subunits

OBJECTIVES:

Water contaminated with arsenic affected millions of people worldwide and arsenic exposure is related to various neurological disorders. Hence, the current study was planned to investigate the neuroprotective activity of diosmin (DSN) against arsenic induced neurotoxicity as an attempt to identify therapeutic intervention to combat arsenicism.

MATERIALS AND METHODS:

Sodium arsenite an inducer of neurotoxicity was administered orally (13 mg/kg) and DSN treatment at two selected doses (50 and 100 mg/kg) was done for 21 days. Behavioral and biochemical variations were examined by various parameters. Furthermore, histopathological and immunohistochemistry studies were done with the brain sections.

RESULTS:

The behavioral studies evidenced that arsenic has suppressed the exploratory behavior and motor coordination in rats and DSN treatment has recovered the behavioral changes to normal. Arsenic administration has also found to induce oxidative stress and DSN co-treatment has ameliorated the oxidative stress markers. Interestingly, depleted levels of neurotransmitters were observed with the arsenic and it was restored back by the DSN treatment. Histopathological alterations like pyknosis of the neuronal cells were identified with arsenic exposure and subsided upon DSN co administration. Immunohistochemical studies have revealed the expression of NOX4 and its gp91^phox and P47^phox subunits and its suppression by DSN treatment may be the key therapeutic factor of it.

CONCLUSIONS:

Treatment with DSN showed a beneficial effect in protecting against arsenic-induced neurotoxicity by suppressing the toxicity changes and the antioxidant effect of DSN might be attributed to its ability of suppressing NOX4 and its subunits.

Hydroxysafflor Yellow A Confers Neuroprotection from Focal Cerebral Ischemia by Modulating the Crosstalk Between JAK2/STAT3 and SOCS3 Signaling Pathways

Natural bioactive compounds have increasingly proved to be promising in evidence- or target-directed treatment or modification of a spectrum of diseases including cerebral ischemic stroke. Hydroxysafflor yellow A (HSYA), a major active component of the safflower plant, has drawn more interests in recent year for its multiple pharmacological actions in the treatment of cerebrovascular and cardiovascular diseases. Although the Janus kinase signaling, such as JAK2/STAT3 pathway, has been implicated in the modulation of the disease, the inhibition or activation of the pathway that contributed to the neuronal prevention from ischemic damages remains controversial. In this study, a series of experiments were performed to examine the dose- and therapeutic time window-related pharmacological efficacies of HSYA with emphasis on the HSYA-modulated interaction of JAK2/STAT3 and SOCS3 signaling in the MCAO rats. We found that HSYA treatment significantly rescued the neurological and functional deficits in a dose-dependent manner in the MCAO rats within 3 h after ischemia. HSYA treatment with a dosage of 8 mg/kg or higher markedly downregulated the expression of the JAK2-mediated signaling that was activated in response to ischemic insult, while it also promoted the expression of SOCS3 coordinately. In the subsequent experiments with the use of the JAK2 inhibitor WP1066, we found that the treatment of WP1066 alone or combination of WP1066/HSYA all exhibited inhibitory effects on JAK2-mediated signaling, while there was no influence on the SOCS3 activity of corresponding efficacious data in the MCAO rats, suggesting that excessive activation of JAK2/STAT3 might be necessary for HSYA to provoke SOCS3-negative feedback signaling. Taking together, our study demonstrates that HSYA might modulate the crosstalk between JAK2/STAT3 and SOCS3 signaling pathways that eventually contributed to its therapeutic roles against cerebral ischemic stroke.

Folic Acid Deficiency Enhances the Tyr705 and Ser727 Phosphorylation of Mitochondrial STAT3 in In Vivo and In Vitro Models of Ischemic Stroke

Ischemic stroke remains one of the most common causes of death and disability worldwide. The stroke patients with an inadequate intake of folic acid tend to have increased brain injury and poorer prognosis. However, the precise mechanisms underlying the harmful effects of folic acid deficiency (FD) in ischemic stroke is still elusive. Here, we aimed to test the hypothesis that mitochondrial localized STAT3 (mitoSTAT3) expression may be involved in the process of neuronal damage induced by FD in in vivo and in vitro models of ischemic stroke. Our results exhibited that FD increased infarct size and aggravated the damage of mitochondrial ultrastructure in ischemic brains. Meanwhile, FD upregulated the phosphorylation levels of mitoSTAT3 at Tyr705 (Y705) and Ser727 (S727) sites in the rat middle cerebral artery occlusion/reperfusion (MCAO/R) model and oxygen-glucose deprivation followed by reperfusion (OGD/R) N2a cells. Furthermore, the inhibition of JAK2 by AG490 led to a significant decrease in FD-induced phosphorylation of Y705, while S727 phosphorylation was unaffected. Conversely, U0126 and LY294002, which respectively inhibited phosphorylation of ERK1/2 and Akt, partially prevented S727 phosphorylation, but had limited effects on the level of pY705, suggesting that phosphorylation of Y705 and S727 is regulated via independent mechanisms in FD-treated brains.

Alpha-pinene exerts neuroprotective effects via anti-inflammatory and anti-apoptotic mechanisms in a rat model of focal cerebral ischemia-reperfusion

BACKGROUND

Ischemic stroke is a severe neurological disorder that affected millions of people worldwide. Neuro-inflammation and apoptosis play an essential role in the pathogenesis of neuronal death during ischemic stroke. Alpha-pinene is a bicyclic terpenoid with anti-inflammatory and anti-apoptotic activities. Accordingly, the main purpose of this study was to assess the protective effect of α-pinene in ischemic stroke.

MATERIALS AND METHODS

To induce ischemic stroke in male Wistar rats, the middle cerebral artery was occluded for 60 min followed by 24 h reperfusion. Alpha-pinene was injected intraperitoneally at the beginning of reperfusion. A day after reperfusion, the neurological deficits, volume of infarct area, and blood-brain barrier (BBB) permeability were evaluated. The mRNA expression of inflammatory cytokines as well as pro- and anti-apoptotic genes was assessed by using reverse transcription-polymerase chain reaction. The protein levels of inflammatory cytokines were also measured by ELISA method.

RESULTS

The results showed that α-pinene (50 and 100 mg/kg) significantly improved sensorimotor function and decreased the volume of infarct area in the brain. The high permeability of BBB was also alleviated by α-pinene (50 and 100 mg/kg) in ischemic areas. Besides, α-pinene (100 mg/kg) attenuated neuro-inflammation through decreasing both the gene and protein expression of TNF-α and IL-1β in the hippocampus, cortex, and striatum. Besides, α-pinene (100 mg/kg) suppressed apoptosis via downregulation of the pro-apoptotic Bax mRNA expression with a concomitant upregulation of anti-apoptotic Bcl-2 gene expression.

CONCLUSIONS

Overall, it was concluded that α-pinene exerts neuroprotective effect during ischemic stroke through attenuating neuroinflammation and inhibition of apoptosis.

Potential anti-TB investigational compounds and drugs with repurposing potential in TB therapy: a conspectus

The latest WHO report estimates about 1.6 million global deaths annually from TB, which is further exacerbated by drug-resistant (DR) TB and comorbidities with diabetes and HIV. Exiguous dosing, incomplete treatment course, and the ability of the tuberculosis bacilli to tolerate and survive current first-line and second-line anti-TB drugs, in either their latent state or active state, has resulted in an increased prevalence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and totally drug-resistant TB (TDR-TB). Although a better understanding of the TB microanatomy, genome, transcriptome, proteome, and metabolome, has resulted in the discovery of a few novel promising anti-TB drug targets and diagnostic biomarkers of late, no new anti-TB drug candidates have been approved for routine therapy in over 50 years, with only bedaquiline, delamanid, and pretomanid recently receiving tentative regulatory approval. Considering this, alternative approaches for identifying possible new anti-TB drug candidates, for effectively eradicating both replicating and non-replicating Mycobacterium tuberculosis, are still urgently required. Subsequently, several antibiotic and non-antibiotic drugs with known treatment indications (TB targeted and non-TB targeted) are now being repurposed and/or derivatized as novel antibiotics for possible use in TB therapy. Insights gathered here reveal that more studies focused on drug-drug interactions between licensed and potential lead anti-TB drug candidates need to be prioritized. This write-up encapsulates the most recent findings regarding investigational compounds with promising anti-TB potential and drugs with repurposing potential in TB therapy.

The JAK2/STAT3 pathway is involved in dexmedetomidine-induced myocardial protection in rats undergoing cardiopulmonary bypass

Background

Many studies have reported that dexmedetomidine protects organs from ischemia/reperfusion-induced injury. However, the mechanism of this protective effect remains inconclusive.

Methods

Rats were randomly divided into 6 groups (n=8). Rats in the sham group were not subjected to cardiopulmonary bypass (CPB) while rats in the other groups underwent CPB for 2 h. Groups L and H received a low and a high dose of dexmedetomidine, respectively. Rats in group AG490 received 10 mg/kg of the Janus kinase 2 (JAK2) inhibitor, AG490, 30 min before anesthesia. Plasma levels of the inflammatory cytokines, interleukin (IL)-6 and IL-10, were measured by enzyme-linked immunosorbent (ELISA), and the apoptosis rate of myocardial cells, the expression of JAK2 and signal transducer and activator of transcription (STAT)3 mRNA, and the protein expression of JAK2, STAT3, pJAK2, pSTAT3, and caspase-3 were analyzed in myocardial tissues by real-time quantitative polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry.

Results

We observed that, in both group L and group H, the level of IL-6 decreased (P<0.05), and the apoptosis rate of myocardial cells were reduced (P<0.05) compared to those in the CPB group. Moreover, qRT-PCR results revealed that dexmedetomidine administration reduced the expression of JAK2 and STAT3 mRNA (P<0.05); pJAK2 and pSTAT3 (P<0.05) protein levels were also reduced as assessed by western blotting and immunohistochemistry (P<0.05).

Conclusions

Dexmedetomidine treatment reduced CPB-related myocardial injury by inhibiting inflammatory reactions and myocardial apoptosis, and can be a potential therapy in CPB-related surgery.

Renalase Attenuates Mouse Fatty Liver Ischemia/Reperfusion Injury through Mitigating Oxidative Stress and Mitochondrial Damage via Activating SIRT1

Liver ischemia/reperfusion (IR) injury is a severe complication of liver surgery. Moreover, nonalcoholic fatty liver disease (NAFLD) patients are particularly vulnerable to IR injury, with higher rates of postoperative morbidity and mortality after liver surgeries. Our previous study found that renalase (RNLS) was highly sensitive and responsive to oxidative stress, which may be a promising biomarker for the evaluation of the severity of liver IR injury. However, the role of RNLS in liver IR injury remains unclear. In the present study, we intensively explored the role and mechanism of RNLS in fatty liver IR injury in vivo and in vitro. C57BL/6 mice were divided into 2 groups feeding with high-fat diet (HFD) and control diet (CD), respectively. After 20 weeks' feeding, they were suffered from portal triad blockage and reflow to induce liver IR injury. Additionally, oleic acid (OA) and tert-butyl hydroperoxide (t-BHP) were used in vitro to induce steatotic hepatocytes and to simulate ROS burst and mimic cellular oxidative stress following portal triad blockage and reflow, respectively. Our data showed that RNLS was downregulated in fatty livers, and RNLS administration effectively attenuated IR injury by reducing ROS production and improving mitochondrial function through activating SIRT1. Additionally, the downregulation of RNLS in the fatty liver was mediated by a decrease of signal transduction and activator of transcription 3 (STAT3) expression under HFD conditions. These findings make RNLS a promising therapeutic strategy for the attenuation of liver IR injury.

Neuroprotective Effect of SCM-198 through Stabilizing Endothelial Cell Function

Leonurine, also named SCM-198, which was extracted from Herba leonuri, displayed a protective effect on various cardiovascular and brain diseases, like ischemic stroke. Ischemic stroke which is the leading cause of morbidity and mortality, ultimately caused irreversible neuron damage. This study is aimed at exploring the possible therapeutic potential of SCM-198 in the protection against postischemic neuronal injury and possible underlying mechanisms. A transient middle cerebral artery occlusion (tMCAO) rat model was utilized to measure the protective effect of SCM-198 on neurons. TEM was used to determine neuron ultrastructural changes. The brain slices were stained with Nissl staining solution for Nissl bodies. Fluoro-Jade B (FJB) was used for staining the degenerating neurons. In the oxygen-glucose deprivation and re-oxygenation (OGD/R) model of bEnd.3 cells treated with SCM-198 (0.1, 1, 10 μM). Then, the bEnd.3 cells were cocultured with SH-SY5Y cells. Cell viability, MDA level, CAT activity, and apoptosis were examined to evaluate the cytotoxicity of these treatments. Western blot and immunofluorescent assays were used to examine the expression of protein related to the p-STAT3/NOX4/Bcl-2 signaling pathway. Coimmunoprecipitation was performed to determine the interaction between p-STAT3 and NOX4. In the transient middle cerebral artery occlusion (tMCAO) rat model, we found that treatment with SCM-198 could ameliorate neuron morphology and reduce the degenerating cell and neuron loss. In the in vitro model of bEnd.3 cell oxygen-glucose deprivation and reoxygenation (OGD/R), treatment with SCM-198 restored the activity of catalase (CAT), improved the expression of Cu-Zn superoxide dismutase (SOD1), and decreased the malondialdehyde (MDA) production. SCM-198 treatment prevented OGD/R-induced cell apoptosis as indicated by increased cell viability and decreased the number of TUNEL-positive cells, accompanied with upregulation of Bcl-2 and Bcl-xl protein and downregulation Bax protein. The results were consistent with SH-SY5Y cells which coculture with bEnd.3 cells. The forthcoming study revealed that SCM-198 activated the p-STAT3/NOX4/Bcl-2 signaling pathway. All the data indicated that SCM-198 protected against oxidative stress and neuronal damage in in vivo and in vitro injury models via the p-STAT3/NOX4/Bcl-2 signaling pathway. Our results suggested that SCM-198 could be the potential drug for neuroprotective effect through stabilizing endothelial cell function.

The Potential Protective Effects of Diosmin on Streptozotocin-Induced Diabetic Cardiomyopathy in Rats

BACKGROUND

Diabetic cardiomyopathy (DCM) is a nonischemic myocardial disorder characterized by metabolic disturbances and oxidative stress in diabetic patients. The present paper aims to determine the protective effect of the phlebotrophic drug, diosmin, on DCM in a model of high-fat diet-fed and streptozotocin-induced type 2 diabetes in the rat.

MATERIALS AND METHODS

The animals were divided into 4 groups (8 rats/group) as follows: vehicle-treated nondiabetic control group, vehicle-treated diabetic group, diosmin (50 mg/kg)-treated diabetic group and diosmin (100 mg/kg)-treated diabetic group. Treatment was given once daily orally by gavage for 6 weeks. Oxidant and antioxidant stress markers, inflammatory markers and proapoptotic and antiapoptotic gene expression using quantified real-time polymerase chain reaction were investigated.

RESULTS

Diosmin treatment in diabetic rats lowered elevated blood glucose levels, homeostatic model assessment for insulin resistance, cardiac creatine kinase and lactate dehydrogenase enzymes, cardiac malondialdehyde and nitric oxide. Moreover, diosmin increased plasma insulin and c-peptide levels, cardiac glutathione content, superoxide dismutase, catalase and glutathione S-transferase activities. Also, diosmin treatment significantly (P < 0.05) lowered the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), down-regulated cardiac Bcl-2-associated X protein and caspase 3 and 9 and up-regulated B-cell lymphoma 2 mRNA expression levels.

CONCLUSIONS

Diosmin may have a sizeable therapeutic potential in the treatment of DCM due to antidiabetic, antioxidative stress, anti-inflammatory and antiapoptotic effects. Detailed studies are needed to disclose the precise mechanisms motivating the protective effect of diosmin‏.

The chondroprotective effect of diosmin on human articular chondrocytes under oxidative stress

Excessive oxidative stress, which can amplify inflammatory responses, is involved in the pathologic progression of knee osteoarthritis. Diosmin is known to possess a variety of biological functions such as antiinflammatory and antioxidant activities. We therefore demonstrated the chondroprotective potentials of diosmin on human articular chondrocytes under oxidative stress. The cytotoxicity of diosmin (5, 10, 50, and 100 μM) to chondrocytes was first evaluated. Subsequently, the cells were treated with diosmin (5 and 10 μM) after hydrogen peroxide (H₂ O₂ ) exposure. We found that the cytotoxicity of diosmin occurred in a dose-dependent manner (10, 50, and 100 μM), and low-dose diosmin (5 μM) slightly impaired cell viability. Diosmin supplementations (5 and 10 μM) did not show beneficial effects on mitochondrial activity, cytotoxicity, proliferation, and survival and the cell senescence was ameliorated in H₂ O₂ -exposed chondrocytes. On the other hand, diosmin down-regulated the mRNA levels of iNOS, COX-2, IL-1β, COL1A1, MMP-3, and MMP-9; up-regulated TIMP-1 and SOX9; and improved COL2A1 in chondrocytes under oxidative stresses. Furthermore, diosmin also regulated glutathione reductase and glutathione peroxidase of H₂ O₂ -exposed chondrocytes. In conclusion, diosmin displayed a remarkable antiinflammatory effect compared with the antioxidant capacity on human chondrocytes. Diosmin can maintain the homeostasis of extracellular matrix of articular cartilage.

Inhibition of miR-337-3p involved in the protection of CoCl2 -induced injury in PC12 cells via activating JAK2/STAT3 signaling pathway

OBJECTIVE

To investigate the possibility of microRNA (miR)-337-3p in the protection of hypoxia-induced injury in PC12 cells via modulating the JAK2/STAT3 signaling pathway.

METHODS

Dual-luciferase reporter assay analyzed the relationship between the miR-337-3p and JAK2. PC12 cells were divided into normal, CoCl₂ , CoCl2 + NC, CoCl2 + inhibitors, CoCl2 + JAK2, and CoCl2 + mimics + JAK2 groups. Then, PC12 cell viability and apoptosis were measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and Annexin-V-fluorescein isothiocyanate/propidium iodide methods. Quantitative real-time polymerase chain reaction and Western blot analysis were used to determine expressions. Besides, the intracellular reactive oxygen species (ROS) was examined by dichloro-dihydro-fluorescein diacetate (DCFH-DA) while the mitochondrial membrane potential (MMP) by using JC-1.

RESULTS

The negative targeting relationship between miR-337-3p and JAK2 was confirmed. When compared with the normal group, miR-337-3p was increased while JAK2 and STAT3 were decreased in CoCl₂ -induced PC12 cells, with decreased cell viability. Moreover, either miR-337-3p inhibitor or JAK2 overexpression could partially reverse CoCl₂ -induced decrease in PC12 cell viability. Besides, CoCl₂ could also trigger PC12 cell apoptosis by increasing cleaved caspase 3 and Bax but decreasing Bcl-2 and Bcl-XL, which, however, were abolished with the transfection of miR-337-3p inhibitors or lentivirus transfection to activate JAK2. Compared with the CoCl₂ group, the average of fluorescent signals of ROS in the CoCl2 + inhibitors group and the CoCl2 + JAK2 group was lower, while the activities of superoxide dismutase, catalase, glutathione peroxidase, and total anti-oxidative capacity were higher, together with an increase in MMP.

CONCLUSION

Inhibiting miR-337-3p could activate the JAK2/STAT3 signaling pathway to suppress CoCl ₂ -induced cytotoxicity and apoptosis and ameliorate oxidative stress and MMP in PC12 cells.

Profiling and comparison of the metabolites of diosmetin and diosmin in rat urine, plasma and feces using UHPLC-LTQ-Orbitrap MSn

Diosmin (diosmetin-7-O-rutinoside) and its aglycone diosmetin, natural bioflavonoids distributing in a variety of citrus fruits and Chinese herbal medicines, possessed positive effects against hepatic, renal, lung, gastric, cerebral and cardiac injury. However, the in vivo metabolic profiles of diosmin and diosmetin in urine, plasma and feces still remain ambiguous. In this study, metabolites of diosmin and diosmetin were identified using an UHPLC-LTQ-Orbitrap MSⁿ strategy coupled with multiple metabolite templates, extracted ion chromatograms (EICs) and diagnostic product ions (DPIs). As a result, 46 diosmetin metabolites and 64 diosmin metabolites were respectively identified in rat biological samples. Methylation, demethylation, hydroxylation, glycosylation, glucuronidation, diglucuronidation and sulfation were common metabolic pathways of diosmetin and diosmin, while demethoxylation, decarbonylation, dihydroxylation and dehydroxylation were particular metabolic pathways of diosmin comparing with that of diosmetin. Diosmetin was not detected in all the biological samples, suggesting that it was quickly transformed into other metabolites in vivo. Diosmin and diosmetin-7-O-glucoside identified in urine and feces as well as their subsequent metabolites accounted for a substantial part of all the diosmin metabolic products. Metabolic profiles of diosmetin and diosmin indicated that they were primarily excreted through the urine route possibly originating from the dominant role of their phase II metabolism in vivo. Our results have provided a better understanding of the similarities and differences in pharmacodynamics and pharmacokinetics of diosmetin and diosmin in the future.

Long noncoding RNA C2dat1 protects H9c2 cells against hypoxia injury by downregulating miR-22

Myocardial ischemia is accompanied with hypoxia injury in myocardial cells. Long noncoding RNAs (lncRNA) CAMK2D-associated transcript 1 (C2dat1) C2dat1) has been linked with several ischemic diseases. However, the investigation regarding its role in myocardial ischemia is relatively rare. The aim of this study was to examine the role of C2dat1 in hypoxia response in H9c2 cells. H9c2 cells were subjected to hypoxia to evoke cell damage. Expressions of C2dat1, miR-22, and VEGF in H9c2 cells were altered by transfection, and then cell survival, migration, and invasion were respectively assessed posttransfection. Regulatory relationship between C2dat1, miR-22, and VEGF, as well as the involvement of PI3K/AKT/mTOR and JAK/STAT3 pathways in H9c2 cells injury was then studied. C2dat1 upregulation ameliorated hypoxia injury in H9c2 cells due to the increased viability, migration, and invasion, as well as the decreased apoptosis. miR-22 was negatively regulated by C2dat1. The effects of C2dat1 on H9c2 cells injured by hypoxia were attenuated when miR-22 was overexpressed. VEGF was a target gene of miR-22, and VEGF exerted similar protective effects to C2dat1. Finally, we found that silence of C2dat1 deactivated PI3K/AKT/mTOR and JAK/STAT3 pathways via regulating miR-22 and its downstream gene VEGF. C2dat1-miR-22-VEGF axis could regulate hypoxia injury in H9c2 cells. C2dat1 alleviated hypoxia injury possibly via downregulating miR-22, then upregulating VEGF, which further enhancing the activation of PI3K/AKT/mTOR and JAK/STAT3 pathways.

Inhibition of Connexin43 hemichannels with Gap19 protects cerebral ischemia/reperfusion injury via the JAK2/STAT3 pathway in mice

Functional disruption of the neurovascular unit may lead to aggravation of ischemic cerebral injury. Connexin43 (Cx43)-dependent gap junctional channels (GJCs) are critical in maintaining brain homeostasis. However, excessive opening of hemichannels (HCs) after cerebral ischemia may cause apoptosis and finally lead to amplification of ischemic injury. Previous studies indicated that Cx43 mimetic peptides Gap26 and Gap27 may protect cerebral ischemic injury, but the latest studies showed they also inhibit the opening of GJCs, which are beneficial for neuroprotection. Recent studies showed that Gap19 is a new specific inhibitor of Cx43 HCs. We investigated the role of Gap19 on cerebral ischemia/reperfusion (I/R) injury in a mouse model of middle cerebral artery occlusion (MCAO). Ventricle-injected Gap19 significantly alleviated infarct volume, neuronal cell damage and neurological deficits after ischemia, the neuroprotective effect of Gap19 was significant stronger than Gap26. Post-treatment with TAT-Gap19 still provided neuroprotection when it was administered intraperitoneally at 4 h after reperfusion. In addition, we found that Gap19 decreased the levels of cleaved caspase-3 and Bax and increased the level of Bcl-2, suggesting the anti-apoptotic activity of specifically blocking the Cx43 HCs. Furthermore, our data indicate that Gap19 treatment increased the levels of phosphorylated JAK2 and STAT3 both in vivo and in vitro. Gap19 inhibited hemichannel activity assessed by dye uptake in astrocytes. And we detected that pSTAT3 co-localized with Cx43 together in astrocytes after oxygen glucose deprivation (OGD) injury. Finally, AG490, a blocker of the JAK2/STAT3 pathway, could reverse the neuroprotective effects of Gap19 both in vivo and in vitro. Our experiment investigated the anti-apoptotic activity of Gap19, the specific inhibitor of Cx43 HCs, and the potential mechanisms. Our results demonstrated that Gap19 plays an anti-apoptotic role via activating the JAK2/STAT3 pathway after cerebral I/R injury, indicating that specific blocking of Cx43 HCs is a potential target for ischemic stroke.

Targeting Keap-1/Nrf-2 pathway and cytoglobin as a potential protective mechanism of diosmin and pentoxifylline against cholestatic liver cirrhosis

AIM

The effects of diosmin (DS), pentoxifylline (PTX) and their combination on inflammatory response, oxidant/antioxidant balance, cytoglobin and cirrhotic reaction during bile duct ligation (BDL) were investigated and explored.

MAIN METHODS

Fifty adult male Wistar albino rats were randomly allocated to five groups as following, sham: received vehicle only, BDL: subjected to common BDL without treatment, BDL plus DS: received 100 mg/kg/day orally, BDL plus PTX: received 50 mg/kg/day orally, BDL plus DS plus PTX: received DS and PTX in the same manner. The test period lasted 28 days, liver tissues and blood samples were collected to investigate biochemical markers (liver function biomarkers, oxidative stress markers, and antifibrotic markers), mRNA expression of Nrf-2, Keap-1, NF-κB-p65 and p38-MAPK by real-time PCR, protein expression of cytoglobin and NF-κB-p65 by western blot and iNOS and eNOS by immunohistochemistry. Histopathological study was performed to confirm our results.

KEY FINDINGS

Chronic BDL induced a significant alteration in liver functions, oxidative stress and fibrotic markers. Furthermore, unfavorable effects on gene and protein expression were observed after BDL. Histopathological findings of this group showed parallel effects. DS, PTX and their combination treatment significantly ameliorated the disturbance that occurred due to BDL. Similar findings were observed in liver histopathology.

SIGNIFICANCE

DS and PTX could mitigate liver cirrhosis through modulation of Keap-1/Nrf-2/GSH and NF-κB-p65/p38-MAPK signaling pathways. In addition, we demonstrated that the hepatoprotective effect of DS and PTX is mediated by up-regulation of cytoglobin with inhibition of fibrotic reaction.

SH2B1 protects against OGD/R‑induced apoptosis in PC12 cells via activation of the JAK2/STAT3 signaling pathway

Apoptosis acts as the primary pathogenesis of cerebral ischemia/reperfusion (I/R) injury. Prior studies have revealed the effects of src homology 2 (SH2)B adaptor protein 1 (SH2B1) in myocardial infarction; however, involvement of SH2B1 in cerebral I/R injury and the underlying mechanisms remain to be investigated. In the present study, neural-like PC12 cells underwent 6 h of oxygen-glucose deprivation (OGD) followed by 24 h of reoxygenation (OGD/R). PC12 cells were pre-transfected with an adenovirus encoding for SH2B1 or GFP prior to exposure to OGD/R. Cell viability, LDH release and the apoptotic cascade were investigated. Reverse transcription-quantitative polymerase chain reaction and western blotting were employed to analyze mRNA and protein expression levels, respectively. The results of the present study revealed that OGD/R reduced SH2B1 expression in PC12 cells, accompanied by suppressed cell viability and enhanced cell death. Adenovirus-mediated SH2B1 overexpression, however, resulted in increased viability, reduced LDH release and a reduction in the expression levels of proteins associated with the apoptotic cascade in PC12 cells under the OGD/R condition. A mechanistic explanation may be that the positive effects of SH2B1 on neurons were in part derived from the activation of the JAK2/STAT3 signaling pathway. Furthermore, abolishment of JAK2/STAT3 signaling using a pharmacological inhibitor suppressed the inhibitory effects of SH2B1 under the OGD/R condition. The results of the present study suggested that SH2B1 may protect PC12 cells from OGD/R injury partially by the JAK2/STAT3-dependent inhibition of apoptosis and may provide a novel therapeutic target for the treatment of cerebral I/R injury.

Adiponectin Attenuates Oxygen-Glucose Deprivation-Induced Mitochondrial Oxidative Injury and Apoptosis in Hippocampal HT22 Cells via the JAK2/STAT3 Pathway

Ischemic stroke is among the leading causes of morbidity and mortality worldwide. Improving the tolerance of neurons to ischemia and reperfusion injury could be a feasible strategy against ischemia. Adiponectin (APN) is a major adipokine that regulates glucose and lipid metabolism and plays an important role in the protection of the cerebral nervous system. We aimed to investigate the effects of APN on oxygen and glucose deprivation (OGD)-induced neuronal injury in hippocampal neuronal HT22 cells. APN displayed neuroprotective effects against OGD, evidenced by increased cell viability and decreased lactate dehydrogenase release and apoptotic rate. Additionally, APN also maintained mitochondrial ultrastructure and transmembrane potential, attenuated reactive oxygen species and malondialdehyde, and increased superoxide dismutase and glutathione peroxidase activity. Moreover, APN promoted Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation, enhanced STAT3 nuclear translocation, increased the Bcl-2/Bax ratio, and decreased cleaved caspase-3. The aforementioned APN-induced effects were almost reversed by a JAK2 inhibitor, AG490. APN may attenuate OGD-induced hippocampal HT22 neuronal impairment by protecting cells against mitochondrial oxidative stress and apoptosis, mediated by JAK2/STAT3 signaling.

Resveratrol provides neuroprotection by regulating the JAK2/STAT3/PI3K/AKT/mTOR pathway after stroke in rats

Ischemic stroke is a common disease with high mortality and morbidity worldwide. One of the important pathophysiological effects of ischemic stroke is apoptosis. A neuroprotective effect is defined as the inhibition of neuronal apoptosis to rescue or delay the infarction in the surviving ischemic penumbra. Resveratrol is a natural polyphenol that reportedly prevents cerebral ischemia injury by regulating the expression of PI3K/AKT/mTOR. Therefore, this study aimed to elucidate the neuroprotective effect of resveratrol on cerebral ischemia/reperfusion injury and to investigate the signaling pathways and mechanisms through which resveratrol regulates apoptosis in the ischemic penumbra. Rats were subjected to middle cerebral artery occlusion for 2 h followed by 24 h reperfusion. Cerebral infarct volume was measured using 2% TTC staining. TUNEL staining was conducted to evaluate neuronal apoptosis. Western blotting and immunohistochemistry were used to detect the proteins involved in the JAK2/STAT3/PI3K/AKT/mTOR pathway. The results suggested that resveratrol significantly improved neurological function, reduced cerebral infarct volume, decreased neuronal damage, and markedly attenuated neuronal apoptosis; these effects were attenuated by the inhibition of PI3K/AKT with LY294002 and JAK2/STAT3 with AG490. We also found that resveratrol significantly upregulated the expression of p-JAK2, p-STAT3, p-AKT, p-mTOR, and BCL-2 and downregulated expression of cleaved caspase-3 and BAX, which was partially reversed by LY294002 and AG490. These results suggested that resveratrol provides a neuroprotective effect against cerebral ischemia/reperfusion injury, which is partially mediated by the activation of JAK2/STAT3 and PI3K/AKT/mTOR. Resveratrol may indirectly upregulate the PI3K/AKT/mTOR pathway by activating JAK2/STAT3.

Rosmarinic acid elicits neuroprotection in ischemic stroke via Nrf2 and heme oxygenase 1 signaling

Rosmarinic acid (RA) can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in CD-1 mice (Beijing Vital River Laboratory Animal Technology, Beijing, China) by occluding the right middle cerebral artery for 1 hour and allowing reperfusion for 24 hours. After intraperitoneally injecting model mice with 10, 20, or 40 mg/kg RA, functional neurological deficits were evaluated using modified Longa scores. Subsequently, cerebral infarct volume was measured using TTC staining and ischemic brain tissue was examined for cell apoptosis with TUNEL staining. Superoxide dismutase activity and malondialdehyde levels were measured by spectrophometry. Expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), Bcl-2, Bax, Akt, and phospho-Ser473 Akt proteins in ischemic brain tissue was detected by western blot, while mRNA levels of Nrf2, HO-1, Bcl-2, and Bax were analyzed using real time quantitative PCR. In addition, HO-1 enzyme activity was measured spectrophotometrically. RA (20 and 40 mg/kg) greatly improved neurological function, reduced infarct volume, decreased cell apoptosis, upregulated Bcl-2 protein and mRNA expression, downregulated Bax protein and mRNA expression, increased HO-1 and Nrf2 protein and mRNA expression, increased superoxide dismutase activity, and decreased malondialdehyde levels in ischemic brain tissue of model mice. However, intraperitoneal injection of a HO-1 inhibitor (10 mg/kg zinc protoporphyrin IX) reversed the neuroprotective effects of RA on HO-1 enzyme activity and Bcl-2 and Bax protein expression. The PI3K/Akt signaling pathway inhibitor LY294002 (10 mM) inhibited Akt phosphorylation, as well as Nrf2 and HO-1 expression. Our findings suggest that RA has anti-oxidative and anti-apoptotic properties that protect against ischemic stroke by a mechanism involving upregulation of Nrf2 and HO-1 expression via the PI3K/Akt signaling pathway.

Dexmedetomidine reduces the neuronal apoptosis related to cardiopulmonary bypass by inhibiting activation of the JAK2-STAT3 pathway

Cardiopulmonary bypass (CPB) constitutes one of the primary methodologies pertaining to cardiac surgery. However, this form of surgery can cause damage to the body. Many studies have reported that dexmedetomidine confers cerebral protection. In this study, we aimed to investigate the effect and mechanism of dexmedetomidine on neuronal apoptosis caused by CPB. Here, rats were treated with different doses of dexmedetomidine by intravenous infusion 2 hours after CPB. We observed that dexmedetomidine treatment to rats reduces the S100β, NSE levels in plasma, and neuronal apoptosis following CPB in a dose-dependent manner. Furthermore, we observed that the beneficial effect of dexmedetomidine treatment following CPB was associated with a reduction in IL6, an inflammatory cytokine in plasma and cortex. Our results suggest that dexmedetomidine provides neuroprotective effects by inhibiting inflammation and reducing neuronal apoptosis. There was a correlation between the protective effect on the brain and the dose of dexmedetomidine. In addition, dexmedetomidine administration inhibits phosphorylation of JAK2 and STAT3 proteins in the hippocampus of rats 2 hours after CPB. Therefore, we speculate that the JAK2–STAT3 pathway plays an important role in the neuroprotective effects of dexmedetomidine following brain injury induced by CPB.