Curcumin Protects against Ischemic Stroke by Titrating Microglia/Macrophage Polarization

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

JOURNAL/nrgr/04.03/01300535-202509000-00022/figure1/v/2024-11-05T132919Z/r/image-tiff Poststroke cognitive impairment is a major secondary effect of ischemic stroke in many patients; however, few options are available for the early diagnosis and treatment of this condition. The aims of this study were to (1) determine the specific relationship between hypoxic and α-synuclein during the occur of poststroke cognitive impairment and (2) assess whether the serum phosphorylated α-synuclein level can be used as a biomarker for poststroke cognitive impairment. We found that the phosphorylated α-synuclein level was significantly increased and showed pathological aggregation around the cerebral infarct area in a mouse model of ischemic stroke. In addition, neuronal α-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia, suggesting that hypoxia is the underlying cause of α-synuclein-mediated pathology in the brains of mice with ischemic stroke. Serum phosphorylated α-synuclein levels in patients with ischemic stroke were significantly lower than those in healthy subjects, and were positively correlated with cognition levels in patients with ischemic stroke. Furthermore, a decrease in serum high-density lipoprotein levels in stroke patients was significantly correlated with a decrease in phosphorylated α-synuclein levels. Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury, some of them exhibited decreased cognitive function and reduced phosphorylated α-synuclein levels. Taken together, our results suggest that serum phosphorylated α-synuclein is a potential biomarker for poststroke cognitive impairment.

Ayahuasca reverses ischemic stroke-induced neuroinflammation and oxidative stress

BACKGROUND

Ischemic stroke is a leading cause of death and disability worldwide. Survivors face disability and psychiatric sequelae resulting from ischemia-induced cell death and associated neuroinflammation, and oxidative stress. Herbal medicines have been shown to elicit neuroprotective effects following stroke due to their anti-inflammatory and antioxidant effects. Preliminary evidence suggests that Ayahuasca (AYA), a decoction made from the vine Banisteriopsis caapi containing β-carbolines and the shrub Psychotria viridis containing N, N-Dimethyltryptamine, might attenuate ischemia-induced neuroinflammation and oxidative stress. Therefore, in this study we investigated the putative protective effects of AYA in the middle cerebral artery occlusion (MCAO) model of ischemic stroke.

METHODS

Wistar rats were subjected to the MCAO stroke model or sham surgery on day 0. After 24-h, rats were treated for three days with AYA (2 and 4 mL/kg, gavage) or saline. Neurological score was assessed for 72-h post-stroke. Rats were tested in the elevated plus maze, open field, and novel object recognition tests to assess locomotion, anxiety-like behavior, and recognition memory. Interleukin (IL)-6, IL-10 myeloperoxidase (MPO) activity, and the nitrite/nitrate (N/N) concentrations were determined in the prefrontal cortex (PFC), hippocampus (HPC), hypothalamus (HYP) and cortex. as markers of inflammation. Oxidative stress was quantified in the same brain areas as measured by the levels of thiobarbituric acid reactive species (TBARS), protein carbonylation, and superoxide dismutase (SOD), and catalase (CAT) activity. Mitochondrial metabolism was assessed quantifying the activity of complex 1(CI), CII, citrate synthase (CS), succinate dehydrogenase (SDH), and creatine kinase (CK).

RESULTS

No differences were observed regarding neurological deficits, locomotion, anxiety-like behavior, and recognition memory. However, AYA reversed the stroke-induced increase in IL-6 levels in the PFC and the HPC, IL-10 in the PFC, HPC, and HYP, MPO activity in the PFC, and N/N concentration and CAT activity in the HYP. Moreover, AYA decreased TBARS levels in the PFC and HPC and brain-derived neurotrophic factor (BDNF) in the PFC, and increased SOD activity in the cortex. Lastly, AYA increased CI activity in the HPC and cortex and decreased SDH and CK activity in the HPC.

CONCLUSION

AYA administration following ischemic stroke modulates oxidative stress and neuroinflammation in the PFC, HPC, and HYP. Despite no significant improvements in neurological or behavioral scores, these molecular changes suggest a neuroprotective role of AYA. Future studies should explore the timing of AYA treatment and putative long-term effects on functional recovery, as well as its potential in other brain regions critical for cognitive and motor functions.

Post-Stroke Recovery: A Review of Hydrogel-Based Phytochemical Delivery Systems

Stroke remains a leading cause of disability worldwide, underscoring the urgent need for novel and innovative therapeutic strategies to enhance neuroprotection, support regeneration, and improve functional recovery. Previous research has shown that phytochemicals such as curcumin, tannic acid, gallic acid, ginsenosides, resveratrol, and isorhamnetin display extensive neuroprotective properties, including antioxidant, anti-inflammatory, and anti-apoptotic effects. These natural compounds could also promote neurogenesis, angiogenesis, and the preservation of the blood-brain barrier. Despite their promising bioactivities, clinical application is often limited by poor solubility, bioavailability, and suboptimal pharmacokinetics. Hydrogels offer a promising solution by encapsulating and controlling the gradual release of these phytochemicals directly at the site of injury. Recent advancements in hydrogel formulations, constructed from biopolymers and functionalized using nanotechnological approaches, could significantly improve the solubility, stability, and targeted delivery of phytochemicals. Controlled release profiles from pH-sensitive and environment-responsive hydrogels could ensure that the compounds' therapeutic effects are optimally timed with individual and critical stages of post-stroke repair. Moreover, hydrogel scaffolds with tailored material properties and biocompatibility can create a favorable microenvironment, reducing secondary inflammation, enhancing tissue regeneration, and potentially improving functional and cognitive outcomes following stroke. This review explores the potential of integrating phytochemicals within hydrogel-based delivery systems specifically designed for post-stroke recovery. The design and synthesis of biocompatible, biodegradable hydrogels functionalized especially with phytochemicals and their applications are also discussed. Lastly, we emphasize the need for additional robust and translatable preclinical studies.

Exosomes: an innovative therapeutic target for cerebral ischemia-reperfusion injury

Ischemic stroke is caused by artery stenosis or occlusion, which reduces blood flow and may cause brain damage. Treatment includes restoring blood supply; however, ischemia-reperfusion can still aggravate tissue injury. Reperfusion injury can increase levels of reactive oxygen species, exacerbate mitochondrial dysfunction, create excessive autophagy and ferroptosis, and cause inflammation during microglial infiltration. Cerebral ischemia-reperfusion injury (CIRI) is a key challenge in the treatment of ischemic stroke. Currently, thrombolysis (e.g., rt-PA therapy) and mechanical thrombectomy are the primary treatments, but their application is restricted by narrow therapeutic windows (<4.5 h) and risks of hemorrhagic complications. Exosomes reduce CIRI by regulating oxidative stress, mitochondrial autophagy, inflammatory responses, and glial cell polarization. In addition, their noncellular characteristics provide a safer alternative to stem cell therapy. This article reviews the research progress of exosomes in CIRI in recent years.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

Temporal Transcriptomic Differences in Stroke Between Diabetic and Non-Diabetic Mice

Diabetes is a key risk factor for ischemic stroke and negatively impacts long-term outcomes post-stroke. However, genomic studies on diabetic stroke remain insufficient. This study aims to investigate the interaction between diabetes and stroke from the acute phase to the early recovery phase by establishing a diabetic stroke animal model and comparing transcriptome sequencing results with those of non-diabetic stroke models. The study identified a greater number of downregulated genes in the diabetic stroke group compared to the non-diabetic group at different stages post-stroke. Functional enrichment analysis revealed an enhanced immune response and a relatively lower neurodegeneration potential in the diabetic group. Post-stroke, a higher presence of CD4 + T cells, eosinophils, and M1 macrophages was observed in the diabetic group. Additionally, time-series analysis identified a set of genes with time-specific expression patterns following diabetic stroke. This study underscores the role of inflammation and immune responses as potential factors exacerbating ischemic stroke in diabetes while also identifying gene regulatory networks at different stages post-stroke. These findings provide new insights into the role of diabetes in stroke and suggest potential therapeutic targets for improving outcomes in diabetic patients.

Effect and mechanism of Dichloroacetate in the treatment of stroke and the resolution strategy for side effect

Stroke is a serious disease that leads to high morbidity and mortality, and ischemic stroke accounts for more than 80% of strokes. At present, the only effective drug recombinant tissue plasminogen activator is limited by its indications, and its clinical application rate is not high. Therefore, it is urgent to develop effective new drugs according to the pathological mechanism. In the hypoxic state after ischemic stroke, anaerobic glycolysis has become the main way to provide energy to the brain. This process is essential for the maintenance of important brain functions and has important implications for recovery after stroke. However, acidosis caused by anaerobic glycolysis and lactic acid accumulation is an important pathological process after ischemic stroke. Dichloroacetate (DCA) is an orphan drug that has been used for decades to treat children with genetic mitochondrial diseases. Some studies have confirmed the role of DCA in stroke, but the conclusions are conflicting because some believe that DCA is not effective for ischemic stroke and may aggravate hemorrhagic stroke. This study reviews these studies and finds that DCA has a good effect on ischemic stroke. DCA can protect ischemic stroke by improving oxidative stress, reducing neuroinflammation, inhibiting apoptosis, protecting blood-brain barrier, and regulating metabolism. We also describe the differences in the outcomes of DCA in the treatment of ischemic stroke and the reasons why DCA aggravate hemorrhagic stroke. In addition, DCA, as a water disinfection byproduct, has been concerned about its toxicity. We describe the causes and solutions of peripheral neuropathy caused by DCA. In summary, this study analyzes the neuroprotective mechanism of DCA in ischemic stroke and the contradiction of the different research results, and discusses the causes and solutions of its adverse effects.

Curcumin Regulates Microglia Polarization to Alleviate Ischemic Stroke by Targeting microRNA-205-5p/Kruppel-Like Factor 2 (KLF2)/Activating Transcription Factor 2 (ATF2) Axis

Ischemic stroke (IS) often causes fearful sequela, even death. Curcumin was beneficial to IS, but its underlying molecular mechanism is unclear. Mice were subjected to middle cerebral artery occlusion (MCAO) surgery, and BV-2 cells were treated with oxygen-glucose deprivation/reoxygenation (OGD/R) induction to establish IS models in vivo and in vitro. Abundance of genes and proteins was determined using quantitative real-time polymerase chain reaction (RT-qPCR), immunofluorescence (IF), and western blot. Interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-10 (IL-10) levels were analyzed using enzyme-linked immunosorbent assay (ELISA). Modified neurological severity score (mNSS), corner test, foot fault test, adhesive removal test, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were applied to evaluate the brain injury of mice. The correlation between miR-205-5p and Kruppel-like factor 2 (KLF2) was affirmed using dual luciferase reporter assay. Our results revealed that curcumin alleviated brain damage in MCAO mice through driving microglia M2 polarization. Of note, curcumin resulted in decreased miR-205-5p expression in MCAO mice. miR-205-5p knockdown resulted in promoted microglia M2 polarization in OGD/R conditions and achieved similar results to curcumin treatment in MCAO mice. Moreover, curcumin played a promoting role in microglia M2 polarization under OGD/R conditions, while miR-205-5p overexpression or KLF2 knockdown abolished these effects. On the mechanism, miR-205-5p was a target of curcumin, and miR-205-5p further interacted with KLF2 to inhibit activating transcription factor 2 (ATF2) expression. miR-205-5p, decreased by curcumin, suppressed microglia M2 polarization to worsen IS injury through the mediating KLF2/ATF2 axis.

Promoting remyelination in central nervous system diseases: Potentials and prospects of natural products and herbal medicine

Myelin damage is frequently associated with central nervous system (CNS) diseases and is a critical factor influencing neurological function and disease prognosis. Nevertheless, the majority of current treatments for the CNS concentrate on gray matter injury and repair strategies, while clinical interventions specifically targeting myelin repair remain unavailable. In recent years, natural products and herbal medicine have achieved considerable progress in the domain of myelin repair, given their remarkable curative effect and low toxic side effects, demonstrating significant therapeutic potential. In this review, we present a rather comprehensive account of the mechanisms underlying myelin formation, injury, and repair, with a particular emphasis on the interactions between oligodendrocytes and other glial cells. Furthermore, we summarize the natural products and herbal medicine currently employed in remyelination along with their mechanisms of action, highlighting the potential and challenges of certain natural compounds to enhance myelin repair. This review aims to facilitate the expedited development of innovative therapeutics derived from natural products and herbal medicine and furnish novel insights into myelin repair in the CNS.

Curcumin-Loaded Gelatin Nanoparticles Cross the Blood-Brain Barrier to Treat Ischemic Stroke by Attenuating Oxidative Stress and Neuroinflammation

Background

Ischemic stroke is a medical emergency for which effective treatment remains inadequate. Curcumin (Cur) is a natural polyphenolic compound that is regarded as a potent neuroprotective agent. Compared to synthetic pharmaceuticals, Cur possesses minimal side effects and exhibits multiple mechanisms of action, offering significant advantages in the treatment of ischemic stroke. However, drawbacks such as poor water solubility and transmembrane permeability limit the efficacy of Cur. In recent years, nano-delivery systems have attracted great interest in the field of stroke therapy as an effective method to improve drug solubility and cross the blood-brain barrier (BBB).

Methods

In this study, a novel nanomedicine (Cur@GAR NPs) for ischemic stroke treatment was developed based on Cur-loaded gelatin nanoparticles (Cur@Gel NPs) that were then functionalized and modified with rabies virus glycoprotein (RVG29) to target brain tissue. The stability, antimicrobial properties, antioxidant properties, neuroprotective effects, neuronal cell uptake, and biocompatibility of Cur@GAR NPs were investigated in vitro. The in vivo therapeutic effect of Cur@GAR NPs on ischemic stroke was investigated in a middle cerebral artery occlusion (MCAO) rat model using the Morris water maze test and the open field test, and the potential mechanism of action was further investigated by histological analysis.

Results

The resulting Cur@GAR NPs improved the solubility of Cur and exhibited good dispersion. In vitro studies have shown that Cur@GAR NPs exhibit great antimicrobial properties, antioxidant properties and intracellular reactive oxygen species (ROS) protection. Notably, RVG29 significantly enhanced the uptake of Cur@GAR NPs by SH-SY5Y cells. Furthermore, in vivo studies verified the role of Cur@GAR NPs in reducing nerve damage and supporting neurological recovery. In the MCAO rat model, Cur@GAR NPs significantly attenuated neuroinflammation, reduced neuronal apoptosis and restored behavioral functions to a great extent.

Conclusion

Together these findings implied that Cur@GAR NPs could provide a novel and promising approach for effective ischemic stroke treatment.

Curcumin loaded hydrogel with double ROS-scavenging effect regulates microglia polarization to promote poststroke rehabilitation

Cyclodextrins are used to include curcumin to form complex, which is subsequently loaded into a reactive oxygen species (ROS) responsive hydrogel (Cur gel). This gel exhibits a dual ROS scavenging effect. The gel can neutralize extracellular ROS to lead to a ROS-sensitive curcumin release. The released curcumin complex can eliminate intracellular ROS. Furthermore, the Cur gel effectively downregulates the expression of CD16 and IL-1β while upregulating CD206 and TGF-β in oxygen and glucose-deprived (OGD) BV2 cells. Additionally, it restores the expression of synaptophysin and PSD95 in OGD N2a cells. Upon injection into the stroke cavity, the Cur gel reduces CD16 expression and increases CD206 expression in the peri-infarct area of stroke mice, indicating an in vivo anti-inflammatory polarization of microglia. Colocalization studies using PSD95 and VGlut-1 stains, along with Golgi staining, reveal enhanced neuroplasticity. As a result, stroke mice treated with the Cur gel exhibit the most significant motor function recovery. Mechanistic investigations demonstrate that the released curcumin complex scavenges ROS and suppresses the activation of the ROS-NF-κB signaling pathway by inhibiting the translocation of p47-phox and p67-phox to lead to anti-inflammatory microglia polarization. Consequently, the Cur gel exhibits promising potential for promoting post-stroke rehabilitation in clinics.

Rapamycin Alleviates Neuronal Injury and Modulates Microglial Activation After Cerebral Ischemia

Neurons and microglia are sensitive to cerebral microcirculation and their responses play a crucial part in the pathological processes, while they are also the main target cells of many drugs used to treat brain diseases. Rapamycin exhibits beneficial effects in many diseases; however, whether it can affect neuronal injury or alter the microglial activation after global cerebral ischemia remains unclear. In this study, we performed global cerebral ischemia combined with rapamycin treatment in CX3CR1GFP/+ mice and explored the effects of rapamycin on neuronal deficit and microglial activation. Our results showed that rapamycin reduced neuronal loss, neurodegeneration, and ultrastructural damage after ischemia by histological staining and transmission electron microscopy (TEM). Interestingly, rapamycin suppressed de-ramification and proliferation of microglia and reduced the density of microglia. Immunofluorescence staining indicated that rapamycin skewed microglial polarization toward an anti-inflammatory state. Furthermore, rapamycin as well suppressed the activation of astrocytes. Meanwhile, quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed a significant reduction of pro-inflammatory factors as well as an elevation of anti-inflammatory factors upon rapamycin treatment. As a result of these effects, behavioral tests showed that rapamycin significantly alleviated the brain injury after stroke. Together, our study suggested that rapamycin attenuated neuronal injury, altered microglial activation state, and provided a more beneficial immune microenvironment for the brain, which could be used as a promising therapeutic approach to treat ischemic cerebrovascular diseases.

Curcumol ameliorates neuroinflammation after cerebral ischemia-reperfusion injury via affecting microglial polarization and Treg/Th17 balance through Nrf2/HO-1 and NF-κB signaling

Neuroinflammation caused by microglia and other immune cells plays pivotal role in cerebral ischemia/reperfusion injury and recovery. Modulating microglial polarization or Treg/Th17 balance from pro-inflammatory phenotype to anti-inflammatory phenotype are promising strategies for the treatment of cerebral ischemia. Curcumol has potential to fight against oxidative stress and inflammation, but whether it has protective effect in cerebral ischemia is uncertain. In the present study, cerebral ischemia was induced in C57BL/6 mice via middle cerebral artery occlusion (MCAO). MCAO mice were treated with curcumol for 7 days, then post-stroke ischemic injury, neurological deficits, microglial polarization and brain leukocyte infiltration were evaluated by TTC staining, behavioural tests, flow cytometry, western blot and immunofluorescence. We found that poststroke administration of curcumol reduced infarct volume, attenuated neuronal damage and inflammation, and improved motor function recovery of MCAO mice. Curcumol skewed microglial polarization toward anti-inflammatory phenotype in MCAO mice in vivo or after oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. In addition, curcumol reduced local T cell infiltration in ischemic brain of MCAO mice and impaired Treg/Th17 balance. Curcumol inhibited ROS production and regulated Nrf2/HO-1 and NF-κB signaling in microglia. Finally, inhibiting Nrf2/HO-1 signaling or activating NF-κB signaling abrogated the influence of curcumol on microglial polarization. In conclusion, curcumol treatment reduced brain damage and neuroinflammation via modulating anti-inflammatory microglial polarization and Treg/Th17 balance through Nrf2/HO-1 and NF-κB signaling. Curcumol might be a promising treatment strategy for stroke patients.

Longevity and anti-aging effects of curcumin supplementation

Aging is a gradual and irreversible process that is accompanied by an overall decline in cellular function and a significant increase in the risk of age-associated disorders. Generally, delaying aging is a more effective method than treating diseases associated with aging. Currently, researchers are focused on natural compounds and their therapeutic and health benefits. Curcumin is the main active substance that is present in turmeric, a spice that is made up of the roots and rhizomes of the Curcuma longa plant. Curcumin demonstrated a positive impact on slowing down the aging process by postponing age-related changes. This compound may have anti-aging properties by changing levels of proteins involved in the aging process, such as sirtuins and AMPK, and inhibiting pro-aging proteins, such as NF-κB and mTOR. In clinical research, this herbal compound has been extensively examined in terms of safety, efficacy, and pharmacokinetics. There are numerous effects of curcumin on mechanisms related to aging and human diseases, so we discuss many of them in detail in this review.

Isobavachalcone alleviates ischemic stroke by suppressing HDAC1 expression and improving M2 polarization

Ischemic stroke is a serious cerebrovascular condition. Isobavachalcone (ISO) has been documented to exhibit an anti-inflammatory effect across a variety of diseases; however, its protective impact on ischemic stroke remains unexplored. In this study, we evaluated the influence of ISO in both transient middle cerebral artery occlusion/reperfusion (tMCAO/R) rat models and oxygen-glucose deprivation/reperfusion (OGD/R) cell models. We observed that pretreatment with 50 mg/kg ISO diminished the volume of brain infarction, reduced brain edema, and ameliorated neurological deficits in rats. A reduction in Nissl bodies was noted in the tMCAO/R group, which was reversed following treatment with 50 mg/kg ISO. TUNEL/NeuN double staining revealed a decrease in TUNEL-positive cells in tMCAO/R rats treated with ISO. Furthermore, ISO treatment suppressed the expression of cleaved caspase-3 and BAX, while elevating the expression of BCL-2 in tMCAO/R rats. The levels of CD86 and iNOS were elevated in tMCAO/R rats; conversely, ISO treatment enhanced the expression of CD206 and Arg-1. Additionally, the expression of TNF-α, IL-6, and IL-1β was elevated in tMCAO/R rats, whereas ISO treatment counteracted this effect. ISO treatment also increased the expression of TGF-β and IL-10 in the ischemic penumbra of tMCAO/R rats. It was found that ISO treatment hindered microglial M1 polarization and favored M2 polarization. Histone Deacetylase 1 (HDAC1) is the downstream target protein of ISO, with ISO treatment resulting in decreased HDAC1 expression in both tMCAO/R rats and OGD/R-induced cells. Overexpression of HDAC1 was shown to promote microglial M1 polarization and inhibit M2 polarization in OGD/R+ISO cells. Overall, ISO treatment mitigated brain damage following ischemic stroke by promoting M2 polarization and attenuated ischemic injury by repressing HDAC1 expression.

An Update on the Application of Nano Phytomedicine as an Emerging Therapeutic Tool for Neurodegenerative Diseases

Abstract:

The existence of the blood-brain barrier (BBB), a densely woven network of blood vessels and endothelial cells designed to prevent the infiltration of foreign substances into the brain, the methods employed in developing treatments for neurodegenerative disorders (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Multiple sclerosis, Amyotrophic lateral sclerosis, and others, pose significant challenges and complexities. These illnesses have had a terrible impact on the human population's health. Because early detection of these problems is poor and no good therapy has been established, they have emerged as the biggest lifethreatening healthcare burden worldwide compared to other significant illnesses. Traditional drug delivery techniques do not offer efficient treatment for NDs due to constraints in the BBB design, efflux pumps, and metabolic enzyme expression. Nanotechnology has the potential to significantly enhance ND therapy by utilizing systems that have been bioengineered to engage with living organisms at the cellular range. Compared to traditional techniques, nanotechnological technologies have several potential ways for crossing the BBB and increasing therapeutic efficacy in the brain. The introduction and growth of nanotechnology indicate promising potential for overcoming this issue. Engineered nanoparticles coupled with therapeutic moieties and imaging agents with dimensions ranging from 1-100 nm can improve effectiveness, cellular uptake, selective transport, and drug delivery to the brain due to their changed physicochemical properties. Conjugates of nanoparticles and medicinal plants, or their constituents known as nano phytomedicine, have recently gained importance in developing cutting-edge neuro-therapeutics due to their abundant natural supply, promising targeted delivery to the brain, and lower potential for adverse effects. This study summarizes the common NDs, their prevalence and pathogenesis, and potential herbal nanoformulation for treating NDs.

Progress in the Treatment of Central Nervous System Diseases Based on Nanosized Traditional Chinese Medicine

Traditional Chinese Medicine (TCM) is widely used in clinical practice to treat diseases related to central nervous system (CNS) damage. However, the blood-brain barrier (BBB) constitutes a significant impediment to the effective delivery of TCM, thus substantially diminishing its efficacy. Advances in nanotechnology and its applications in TCM (also known as nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain region. This review provides an overview of the physiological and pathological mechanisms of the BBB and systematically classifies the common TCM used to treat CNS diseases and types of nanocarriers that effectively deliver TCM to the brain. Additionally, drug delivery strategies for nano-TCMs that utilize in vivo physiological properties or in vitro devices to bypass or cross the BBB are discussed. This review further focuses on the application of nano-TCMs in the treatment of various CNS diseases. Finally, this article anticipates a design strategy for nano-TCMs with higher delivery efficiency and probes their application potential in treating a wider range of CNS diseases.

Curcumin Lowers the Accelerated Speed of Epileptogenesis by Traumatic Brain Injury

Background

Traumatic brain injury or TBI can underlie epilepsy. Prevention of PTE has been of great interest to scientists. Given the antiepileptic, antioxidant and anti-inflammatory activities of curcumin, we examined whether this compound can affect epileptogenesis in rats after TBI.

Methods

Curcumin was injected once a day for two weeks. TBI was induced in the temporal cortex of anesthetized rats using a controlled cortical impact device. One day after TBI, pentylenetetrazole (PTZ), 35 mg/kg, was injected i.p. every other day until manifestation of generalized seizures. The number of PTZ injections was then recorded. Moreover, the extent of cortical and hippocampal IL-1β and glial fibrillary acidic protein (GFAP) expression in the epileptic rats were measured by Western blot analysis.

Results

Curcumin 50 and 150 mg/kg prevented the development of kindling, whereas TBI accelerated the rate of kindling. Curcumin 20 mg/kg prohibited kindling facilitation by TBI, and reduced the expression of IL-1β and GFAP induced by TBI.

Conclusion

Curcumin can stop the acceleration of epileptogenesis after TBI in rats. Inhibiting hippocampal and cortical overexpression of IL-1β and GFAP seems to be involved in this activity.

Identification of hypoxia- and immune-related biomarkers in patients with ischemic stroke

Background

The immune microenvironment and hypoxia play crucial roles in the pathophysiology of ischemic stroke (IS). Hence, in this study, we aimed to identify hypoxia- and immune-related biomarkers in IS.

Methods

The IS microarray dataset GSE16561 was examined to determine differentially expressed genes (DEGs) utilizing bioinformatics-based analysis. The intersection of hypoxia-related genes and DEGs was conducted to identify differentially expressed hypoxia-related genes (DEHRGs). Then, using weighted correlation network analysis (WGCNA), all of the genes in GSE16561 dataset were examined to create a co-expression network, and module-clinical trait correlations were examined for the purpose of examining the genes linked to immune cells. The immune-related DEHRGs were submitted to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. A protein-protein interaction (PPI) network was constructed by Cytoscape plugin MCODE, in order to extract hub genes. The miRNet was used to predict hub gene-related transcription factors (TFs) and miRNAs. Finally, a diagnostic model was developed by least absolute shrinkage and selection operator (LASSO) logistic regression.

Results

Between the control and IS samples, 4171 DEGs were found. Thereafter, the intersection of hypoxia-related genes and DEGs was conducted to obtain 45 DEHRGs. Ten significantly differentially infiltrated immune cells were found-namely, CD56dim natural killer cells, activated CD8 T cells, activated dendritic cells, activated B cells, central memory CD8 T cells, effector memory CD8 T cells, natural killer cells, gamma delta T cells, plasmacytoid dendritic cells, and neutrophils-between IS and control samples. Subsequently, we identified 27 immune-related DEHRGs through the intersection of DEHRGs and genes in important modules of WGCNA. The immune-related DEHRGs were primarily enriched in response to hypoxia, cellular polysaccharide metabolic process, response to decreased oxygen levels, polysaccharide metabolic process, lipid and atherosclerosis, and HIF-1 signaling pathway H. Using MCODE, FOS, DDIT3, DUSP1, and NFIL3 were found to be hub genes. In the validation cohort and training set, the AUC values of the diagnostic model were 0.9188034 and 0.9395085, respectively.

Conclusion

In brief, we identified and validated four hub genes-FOS, DDIT3, DUSP1, and NFIL3-which might be involved in the pathological development of IS, potentially providing novel perspectives for the diagnosis and treatment of IS.

The role and therapeutic potential of nuclear factor κB (NF-κB) in ischemic stroke

Stroke is a prevalent cerebrovascular condition with a global impact, causing significant rates of illness and death. Despite extensive research, the available treatment options for stroke remain restricted. Hence, it is crucial to gain a deeper understanding of the molecular mechanisms associated with the onset and advancement of stroke in order to establish a theoretical foundation for novel preventive and therapeutic approaches. NF-κB, also known as nuclear factor κB, is a transcription factor responsible for controlling the expression of numerous genes and plays a crucial role in diverse physiological processes. NF-κB is triggered and regulates neuroinflammation and other processes after stroke, promoting the generation of cytokine storms and contributing to the advancement of ischemic stroke (IS). Therefore, NF-κB could potentially play a vital role in stroke by regulating diverse pathophysiological processes. This review provides an overview of the functions of NF-κB in stroke and its governing mechanisms. In addition, our attention is directed towards various potential therapies that aim to inhibit the NF-κB signaling pathway in order to offer valuable insights for the advancement of innovative treatment approaches for stroke.

Exploring Chinese herbal medicine for ischemic stroke: insights into microglia and signaling pathways

Ischemic stroke is a prevalent clinical condition affecting the central nervous system, characterized by a high mortality and disability rate. Its incidence is progressively rising, particularly among younger individuals, posing a significant threat to human well-being. The activation and polarization of microglia, leading to pro-inflammatory and anti-inflammatory responses, are widely recognized as pivotal factors in the pathogenesis of cerebral ischemia and reperfusion injury. Traditional Chinese herbal medicines (TCHMs) boasts a rich historical background, notable efficacy, and minimal adverse effects. It exerts its effects by modulating microglia activation and polarization, suppressing inflammatory responses, and ameliorating nerve injury through the mediation of microglia and various associated pathways (such as NF-κB signaling pathway, Toll-like signaling pathway, Notch signaling pathway, AMPK signaling pathway, MAPK signaling pathway, among others). Consequently, this article focuses on microglia as a therapeutic target, reviewing relevant pathway of literature on TCHMs to mitigate neuroinflammation and mediate IS injury, while also exploring research on drug delivery of TCHMs. The ultimate goal is to provide new insights that can contribute to the clinical management of IS using TCHMs.

Mechanisms of immune response and cell death in ischemic stroke and their regulation by natural compounds

Ischemic stroke (IS), which is the third foremost cause of disability and death worldwide, has inflammation and cell death as its main pathological features. IS can lead to neuronal cell death and release factors such as damage-related molecular patterns, stimulating the immune system to release inflammatory mediators, thereby resulting in inflammation and exacerbating brain damage. Currently, there are a limited number of treatment methods for IS, which is a fact necessitating the discovery of new treatment targets. For this review, current research on inflammation and cell death in ischemic stroke was summarized. The complex roles and pathways of the principal immune cells (microglia, astrocyte, neutrophils, T lymphocytes, and monocytes/macrophage) in the immune system after IS in inflammation are discussed. The mechanisms of immune cell interactions and the cytokines involved in these interactions are summarized. Moreover, the cell death mechanisms (pyroptosis, apoptosis, necroptosis, PANoptosis, and ferroptosis) and pathways after IS are explored. Finally, a summary is provided of the mechanism of action of natural pharmacological active ingredients in the treatment of IS. Despite significant recent progress in research on IS, there remain many challenges that need to be overcome.

Curcumin and analogues in mitigating liver injury and disease consequences: From molecular mechanisms to clinical perspectives

BACKGROUND

Liver injury is a prevalent global health concern, impacting a substantial number of individuals and leading to elevated mortality rates and socioeconomic burdens. Traditional primary treatment options encounter resource constraints and high costs, prompting exploration of alternative adjunct therapies, such as phytotherapy. Curcumin demonstrates significant therapeutic potential across various medical conditions, particularly emerging as a promising candidate for liver injury treatment.

PURPOSE

This study aims to provide current evidence maps of curcumin and its analogs in the context of liver injury, covering aspects of biosafety, toxicology, and clinical trials. Importantly, it seeks to summarize the intricate mechanisms modulated by curcumin.

METHODS

We conducted a comprehensive search of MEDLINE, Web of Science, and Embase up to July 2023. Titles and abstracts were reviewed to identify studies that met our eligibility criteria. The screening process involved three authors independently assessing the potential of curcumin mitigating liver injury and its disease consequences by reviewing titles, abstracts, and full texts.

RESULTS

Curcumin and its analogs have demonstrated low toxicity in vitro and in vivo. However, the limited bioavailability has hindered their advanced use in liver injury. This limitation can potentially be addressed by nano-curcumin and emerging drug delivery systems. Curcumin plays a role in alleviating liver injury by modulating the antioxidant system, as well as cellular and molecular pathways. The specific mechanisms involve multiple pathways, such as NF-κB, p38/MAPK, and JAK2/STAT3, and the pro-apoptosis Bcl-2/Bax/caspase-3 axis in damaged cells. Additionally, curcumin targets nutritional metabolism, regulating the substance in liver cells and tissues. The microenvironment associated with liver injury, like extracellular matrix and immune cells and factors, is also regulated by curcumin. Initial evaluation of curcumin and its analogs through 12 clinical trials demonstrates their potential application in liver injury.

CONCLUSION

Curcumin emerges as a promising phytomedicine for liver injury owing to its effectiveness in hepatoprotection and low toxicity profile. Nevertheless, in-depth investigations are warranted to unravel the complex mechanisms through which curcumin influences liver tissues and overall physiological milieu. Moreover, extensive clinical trials are essential to determine optimal curcumin dosage forms, maximizing its benefits and achieving favorable clinical outcomes.

Blood-brain Barrier and Neurovascular Unit Dysfunction in Parkinson's Disease: From Clinical Insights to Pathogenic Mechanisms and Novel Therapeutic Approaches

The blood-brain barrier (BBB) plays a crucial role in the central nervous system by tightly regulating the influx and efflux of biological substances between the brain parenchyma and peripheral circulation. Its restrictive nature acts as an obstacle to protect the brain from potentially noxious substances such as blood-borne toxins, immune cells, and pathogens. Thus, the maintenance of its structural and functional integrity is vital in the preservation of neuronal function and cellular homeostasis in the brain microenvironment. However, the barrier's foundation can become compromised during neurological or pathological conditions, which can result in dysregulated ionic homeostasis, impaired transport of nutrients, and accumulation of neurotoxins that eventually lead to irreversible neuronal loss. Initially, the BBB is thought to remain intact during neurodegenerative diseases, but accumulating evidence as of late has suggested the possible association of BBB dysfunction with Parkinson's disease (PD) pathology. The neurodegeneration occurring in PD is believed to stem from a myriad of pathogenic mechanisms, including tight junction alterations, abnormal angiogenesis, and dysfunctional BBB transporter mechanism, which ultimately causes altered BBB permeability. In this review, the major elements of the neurovascular unit (NVU) comprising the BBB are discussed, along with their role in the maintenance of barrier integrity and PD pathogenesis. We also elaborated on how the neuroendocrine system can influence the regulation of BBB function and PD pathogenesis. Several novel therapeutic approaches targeting the NVU components are explored to provide a fresh outlook on treatment options for PD.

Insights on Natural Products Against Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that causes the death of motor neurons and consequent muscle paralysis. Despite many efforts to address it, current therapy targeting ALS remains limited, increasing the interest in complementary therapies. Over the years, several herbal preparations and medicinal plants have been studied to prevent and treat this disease, which has received remarkable attention due to their blood-brain barrier penetration properties and low toxicity. Thus, this review presents the therapeutic potential of a variety of medicinal herbs and their relationship with ALS and their physiopathological pathways.

The effects of curcumin-piperine supplementation on inflammatory, oxidative stress and metabolic indices in patients with ischemic stroke in the rehabilitation phase: a randomized controlled trial

BACKGROUND

Stroke is a leading cause of death worldwide, which is associated with a heavy economic and social burden. The purpose of this study was to investigate the effects of supplementation with curcumin-piperine combination in patients with ischemic stroke in the rehabilitation stage.

METHODS

In this randomized controlled trial, 66 patients with stroke were randomized into two groups receiving curcumin-piperine tablets (500 mg curcumin + 5 mg piperine) and matched placebo tablets for 12 weeks. High-sensitivity C-reactive protein (hs-CRP), carotid intima-media thickness (CIMT), thrombosis, total antioxidant capacity (TAC), lipid profile, anthropometric indices, blood pressure, and quality of life were assessed before and after the intervention. Statistical data analysis was done using SPSS22 software.

RESULTS

A total of 56 patients with a mean age of 59.80 ± 4.25 years completed the trial. Based on ANCOVA test, adjusted for baseline values, curcumin-piperine supplementation for 12 weeks resulted in significant reductions in serum levels of hs-CRP (p = 0.026), total cholesterol (TC) (p = 0.009), triglycerides (TG) (p = 0.001), CIMT (p = 0.002), weight (P = 0.001), waist circumference (p = 0.024), and systolic and diastolic blood pressure (p < 0.001), and a significant increase in TAC (p < 0.001) in comparison to the placebo. Pain score significantly increased in both groups; however, its increase was significantly higher in the placebo group compared with the intervention group (p = 0.007). No significant changes were observed between the two groups in terms of serum fibrinogen, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and quality of life indices.

CONCLUSION

Curcumin-piperine supplementation had beneficial effects on CIMT, serum hs-CRP, TC, TG, TAC, and systolic and diastolic blood pressure in patients with ischemic stroke in the rehabilitation stage.

Panax notoginseng: derived exosome-like nanoparticles attenuate ischemia reperfusion injury via altering microglia polarization

Cerebral ischemia/reperfusion (CI/R) injury is a clinical conundrum during the treatment of ischemic stroke. Cell-derived exosomes (CDE) were proved to be therapeutically effective for CI/R injury. However, production of CDE is time and effort consuming. Increasing studies reported that plants can also generate exosome-like nanoparticles (ELN) which are therapeutically effective and have higher yield compared with CDE. In this study, a commonly used Chinese herb Panax notoginseng (PN), whose active ingredients were well-documented in the treatment of CI/R injury, was chosen as a source of ELNs. It was found that Panax notoginseng derived exosome like nanoparticles (PDN) could enter the brain without modification and ameliorate cerebral infarct volume, improve behavior outcome and maintained the integrity of BBB. PDNs attenuated CI/R injury by altering the phenotype of microglia from "pro-inflammation" M1 type to "anti-inflammation" M2 type. Also, we found that lipids from PDNs were the major therapeutic effective component. As a mechanism of action, PDN was proved to exert therapeutic effect via activating pI3k/Akt pathway.

Levistilide A ameliorates neuroinflammation via inhibiting JAK2/STAT3 signaling for neuroprotection and cognitive improvement in scopolamine-induced Alzheimer's disease mouse model

Alzheimer's disease (AD) is a progressive neurodegenerative disease associated with cognitive impairment and dementia, which has become a major public health problem. There are no effective therapeutic agents used to treat AD in clinic for the extremely complex pathogenesis. Here we identify Levistilide A (LA), one of the major active natural terpene lactone constituents from Chinese herbal medicine Angelicae sinensis and Chuanxiong Rhizoma, as a potent neuroinflammation inhibitor for neuroprotection and cognitive improvement of AD. We show that LA suppresses neuronal apoptosis, restores cholinergic system function, and lowers neuroinflammation in vivo to improve scopolamine (SCOP)-induced learning and memory deficits. In addition, LA inhibits the release of IL-1β, IL-6 and TNF-α, while increasing the production of IL-4 and IL-10 for anti-inflammatory effects in LPS or Aβ-induced BV2 and HMC3 cells. Furthermore, the conditioned medium (CM) from LA-treated BV2 or HMC3 cells enhances the viability of SH-SY5Y and HT-22 cells, and LA reverses M1 to M2 phenotype transformation of BV2 and HMC3 cells accompanied by the inhibited Iba-1 expression and mRNA level of IL-1β, IL-6, TNF-α and NOS2, and the increased expression of ARG1, CD206 and CD163. Mechanistically, we analyze JAK2/STAT3 signaling as possible targets of LA using network pharmacology approaches, and further experimentally validate that LA inhibits the phosphorylation of JAK2 and STAT3, and STAT3 expression within nucleus both in vitro and in vivo. Collectively, we identify LA as a potential neuroinflammation inhibitor for neuroprotection and cognitive improvement, which is expected to be a candidate for AD therapy.

Nanoarchitectonics of tannic acid based injectable hydrogel regulate the microglial phenotype to enhance neuroplasticity for poststroke rehabilitation

BACKGROUND

Stroke is the second leading cause of mortality and disability worldwide. Poststroke rehabilitation is still unsatisfactory in clinics, which brings great pain and economic burdens to stroke patients. In this study, an injectable hydrogel in which tannic acid (TA) acts as not only a building block but also a therapeutic drug, was developed for poststroke rehabilitation.

METHODS

TA is used as a building block to form an injectable hydrogel (TA gel) with carboxymethyl chitosan (CMCS) by multivalent hydrogen bonds. The morphology, rheological properties, and TA release behavior of the hydrogel were characterized. The abilities of the TA gel to modulate microglial (BV2 cells) polarization and subsequently enhance the neuroplasticity of neuro cells (N2a cells) were assessed in vitro. The TA gel was injected into the cavity of stroke mice to evaluate motor function recovery, microglial polarization, and neuroplasticity in vivo. The molecular pathway through which TA modulates microglial polarization was also explored both in vitro and in vivo.

RESULTS

The TA gel exhibited sustainable release behavior of TA. The TA gel can suppress the expression of CD16 and IL-1β, and upregulate the expression of CD206 and TGF-β in oxygen and glucose-deprived (OGD) BV2 cells, indicating the regulation of OGD BV2 cells to an anti-inflammatory phenotype in vitro. This finding further shows that the decrease in synaptophysin and PSD95 in OGD N2a cells is effectively recovered by anti-inflammatory BV2 cells. Furthermore, the TA gel decreased CD16/iNOS expression and increased CD206 expression in the peri-infarct area of stroke mice, implying anti-inflammatory polarization of microglia in vivo. The colocalization of PSD95 and Vglut1 stains, as well as Golgi staining, showed the enhancement of neuroplasticity by the TA gel. Spontaneously, the TA gel successfully recovered the motor function of stroke mice. The western blot results in vitro and in vivo suggested that the TA gel regulated microglial polarization via the NF-κB pathway.

CONCLUSION

The TA gel serves as an effective brain injectable implant to treat stroke and shows promising potential to promote poststroke rehabilitation in the clinic.

Pharmacological intervention of curcumin via the NLRP3 inflammasome in ischemic stroke

Ischemic-induced neuronal injury arises due to low oxygen/nutrient levels and an inflammatory response that exacerbates neuronal loss. NOD-like receptor family pyrin domain-containing 3 (NLRP3) is an important regulator of inflammation after ischemic stroke, with its inhibition being involved in nerve regeneration. Curcumin, a main active ingredient in Chinese herbs, plays a positive role in neuronal repair and neuroprotection by regulating the NLRP3 signaling pathway. Nevertheless, the signaling mechanisms relating to how curcumin regulates NLRP3 inflammasome in inflammation and neural restoration following ischemic stroke are unknown. In this report, we summarize the main biological functions of the NLRP3 inflammasome along with the neuroprotective effects and underlying mechanisms of curcumin via impairment of the NLRP3 pathway in ischemic brain injury. We also discuss the role of medicinal interventions that target the NLRP3 and potential pathways, as well as possible directions for curcumin therapy to penetrate the blood-brain barrier (BBB) and hinder inflammation in ischemic stroke. This report conclusively demonstrates that curcumin has neuroprotective properties that inhibit inflammation and prevent nerve cell loss, thereby delaying the progression of ischemic brain damage.

Montelukast sodium protects against focal cerebral ischemic injury by regulating inflammatory reaction via promoting microglia polarization

BACKGROUND

Neuroinflammation plays an important role in brain injury and repair. Regulation of post-stroke inflammation may be a reasonable strategy to treat ischemic stroke. The present study demonstrates that montelukast sodium protected brain tissue by regulating the post-stroke inflammatory reaction.

METHODS

Adult male mice underwent distal occlusion of the middle cerebral artery (d-MCAO) surgery, followed by intraperitoneal injection of montelukast sodium or equivalent saline, from day 0-7 after the operation. On the 7th day, Rotarod and adhesive-removal test were performed. M AP2 staining, and Iba1, CD206, and CD16/32 co staining were performed. BV2 microglial cell lines were co-cultured with different concentrations of montelukast sodium with or without lipopolysaccharide (LPS). Real-time polymerase chain reaction (rt-PCR) and enzyme linked immunosorbent assay (ELISA) were used to detect the mRNA expression of M1 and M2 phenotypic microglia markers and the release of cytokines representing from different phenotypes of microglia cells.

RESULTS

Montelukast sodium prolonged the time that d-MCAO mice remained on the rotating bar, shortened the time to remove the sticker on the opposite claw, and reduced the infarct volume, promoting the transformation of microglial cells/macrophages around the infarct to the M2 phenotype. Montelukast sodium increased the mRNA expression of Arg-1, CD206, TGF-β, and IL-10 in BV2 microglial cell lines stimulated by LPS, while decreased the expression of iNOS, TNF-α, and CD16/32.

CONCLUSION

Montelukast sodium can protect against focal cerebral ischemic injury by regulating inflammatory reaction via promoting microglia polarization.

Research progress on the mechanism of curcumin in cerebral ischemia/reperfusion injury: a narrative review

Cerebral ischemia/reperfusion (I/R) injury can result in different levels of cerebral impairment, and in severe cases, death. Curcumin, an essential bioactive component of turmeric, has a rich history as a traditional medicine for various ailments in numerous countries. Experimental and clinical research has established that curcumin offers a protective effect against cerebral I/R injury. Curcumin exerts its protective effects by acting on specific mechanisms such as antioxidant, anti-inflammatory, inhibition of ferroptosis and pyroptosis, protection of mitochondrial function and structure, reduction of excessive autophagy, and improvement of endoplasmic reticulum (ER) stress, which ultimately help to preserve the blood-brain barrier (BBB) and reducing apoptosis. There is currently a shortage of drugs undergoing clinical trials for the treatment of cerebral I/R injury, highlighting the pressing need for research and development of novel treatments to address this injury. The primary objective of this study is to establish a theoretical basis for future clinical applications of curcumin by delineating the mechanisms and protective effects of curcumin against cerebral I/R injury. Adapted with permission from [1].

Regulation of microglia polarization after cerebral ischemia

Stroke ranks second as a leading cause of death and permanent disability globally. Microglia, innate immune cells in the brain, respond rapidly to ischemic injury, triggering a robust and persistent neuroinflammatory reaction throughout the disease's progression. Neuroinflammation plays a critical role in the mechanism of secondary injury in ischemic stroke and is a significant controllable factor. Microglia activation takes on two general phenotypes: the pro-inflammatory M1 type and the anti-inflammatory M2 type, although the reality is more complex. The regulation of microglia phenotype is crucial to controlling the neuroinflammatory response. This review summarized the key molecules and mechanisms of microglia polarization, function, and phenotypic transformation following cerebral ischemia, with a focus on the influence of autophagy on microglia polarization. The goal is to provide a reference for the development of new targets for the treatment for ischemic stroke treatment based on the regulation of microglia polarization.

GLP-1R knockdown abrogates the protective effects of liraglutide on ischaemic stroke via inhibition of M2 polarisation and activation of NLRP3 inflammasome by reducing Nrf2 activation

Liraglutide has been recently discovered to penetrate the blood-brain barrier to exert neuroprotective effects. However, relevant mechanisms of the protective effects of liraglutide on ischaemic stroke remain to be elucidated. This study examined the mechanism of GLP-1R in regulating the protective effect of liraglutide against ischaemic stroke. Middle cerebral artery occlusion (MCAO) male Sprague-Dawley rat model with/without GLP-1R or Nrf2 knockdown was established and subjected to liraglutide treatment. Then neurological deficit and brain oedema of rats was evaluated and brain tissues were subjected to TTC, Nissl, TUNEL and immunofluorescence staining. Rat primary microglial cells firstly underwent lipopolysaccharide (LPS) treatment, then GLP-1R or Nrf2 knockdown treatment, and finally Liraglutide treatment to research the NLRP3 activation. As a result, Liraglutide protected rats' brain tissues after MCAO, which attenuated brain oedema, infarct volume, neurological deficit score, neuronal apoptosis and Iba1 expression but enhanced live neurons. However, GLP-1R knockdown abrogated these protective effects of liraglutide on MCAO rats. According to in vitro experiments, Liraglutide promoted M2 polarisation, activated Nrf2 and inhibited NLRP3 activation in LPS-induced microglial cells, but GLP-1R or Nrf2 knockdown reversed these effects of Liraglutide on LPS-induced microglial cells. Further, Nrf2 knockdown counteracted the protection of liraglutide on MCAO rats, whereas sulforaphane (agonist of Nrf2) counteracted the effect of Nrf2 knockdown on liraglutide-treated MCAO rats. Collectively, GLP-1R knockdown abrogated the protection of liraglutide on MCAO rats by activating NLRP3 via inactivating Nrf2.

Regulatory mechanisms of natural compounds from traditional Chinese herbal medicines on the microglial response in ischemic stroke

BACKGROUND

Development of clinically effective neuroprotective agents for stroke therapy is still a challenging task. Microglia play a critical role in brain injury and recovery after ischemic stroke. Traditional Chinese herbal medicines (TCHMs) are based on a unique therapeutic principle, have various formulas, and have long been widely used to treat stroke. Therefore, the active compounds in TCHMs and their underlying mechanisms of action are attracting increasing attention in the field of stroke drug development.

PURPOSE

To summarize the regulatory mechanisms of TCHM-derived natural compounds on the microglial response in animal models of ischemic stroke.

METHODS

We searched studies published until 10 April 2023 in the Web of Science, PubMed, and ScienceDirect using the following keywords: natural compounds, natural products or phytochemicals, traditional Chinese Medicine or Chinese herbal medicine, microglia, and ischemic stroke. This review was prepared according to PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analysis) guidelines.

RESULTS

Natural compounds derived from TCHMs can attenuate the M1 phenotype of microglia, which is involved in the detrimental inflammatory response, via inhibition of NF-κB, MAPKs, JAK/STAT, Notch, TLR4, P2X7R, CX3CR1, IL-17RA, the NLRP3 inflammasome, and pro-oxidant enzymes. Additionally, the neuroprotective response of microglia with the M2 phenotype can be enhanced by activating Nrf2/HO-1, PI3K/AKT, AMPK, PPARγ, SIRT1, CB2R, TREM2, nAChR, and IL-33/ST2. Several clinical trials showed that TCHM-derived natural compounds that regulate microglial responses have significant and safe therapeutic effects, but further well-designed clinical studies are needed.

CONCLUSIONS

Further research regarding the direct targets and potential pleiotropic or synergistic effects of natural compounds would provide a more reasonable approach for regulation of the microglial response with the possibility of successful stroke drug development.

Else_BRB_110660Docosahexaenoic acid promotes M2 microglia phenotype via activating PPARγ-mediated ERK/AKT pathway against cerebral ischemia-reperfusion injury

In ischemia-reperfusion stroke, microglia play a dual role in brain injury as well as brain repair, and promoting their switch from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 phenotype is considered to be a potential therapeutic strategy. Docosahexaenoic acid (DHA) is an essential long-chain omega-3 polyunsaturated fatty acid that exhibits potent anti-inflammatory properties in the acute phase of ischemic stroke, but its effect on microglia polarization is unknown. Thus, the objective of this study was to investigate the neuroprotective effects of DHA on rat brain following ischemia-reperfusion injury, and to investigate the mechanism by which DHA regulates microglia polarization. We administered DHA 5mg/kg intraperitoneally daily for 3 d following a transient middle cerebral artery occlusion reperfusion model in rats. The protective effects of DHA on cerebral ischemia-reperfusion injury were detected by TTC staining, HE staining, Nissler staining, and TUNEL staining. Quantitative real-time PCR, immunofluorescence, western blot, and enzyme-linked immunosorbent assay were used to detect the expression of M1 and M2 microglia-associated markers and PPARγ-mediated ERK/AKT signaling pathway proteins. We found that DHA significantly improved brain injury by decreasing the expression of the M1 phenotypic marker (iNOS, CD16) and increasing the expression of the M2 phenotypic marker (Arg-1, CD206). DHA also increased the expression of peroxisome proliferator-activated receptor gamma (PPARγ) mRNA and protein, increased the expression of the pathway protein AKT, and decreased the expression of ERK1/2. In addition, DHA promoted the expression of anti-inflammatory factor IL-10 and decreased the expression of pro-inflammatory factors TNF-α and IL-1β. However, the PPARγ antagonist GW9662 greatly blocked these beneficial effects. These results suggest that DHA may activate PPARγ to inhibit ERK and activate AKT signaling pathways to regulate microglia polarization, thereby reducing neuroinflammation and promoting neurological recovery to alleviate cerebral ischemia-reperfusion injury.

Low-dose curcumin enhances hippocampal neurogenesis and memory retention in young mice

Adult neurogenesis generates new functional neurons from adult neural stem cells in various regions, including the subventricular zone (SVZ) of the lateral ventricles and subgranular zone (SGZ) of hippocampal dentate gyrus (DG). Available evidence shows hippocampal neurogenesis can be negatively or positively regulated by dietary components. In a previous study, we reported that curcumin (diferuloylmethane; a polyphenolic found in curry spice) stimulates the proliferation of embryonic neural stem cells (NSCs) by activating adaptive cellular stress responses. Here, we investigated whether subchronic administration of curcumin (once daily at 0.4, 2, or 10 mg/kg for 14 days) promotes hippocampal neurogenesis and neurocognitive function in young (5-week-old) mice. Oral administration of low-dose curcumin (0.4 mg/kg) increased the proliferation and survival of newly generated cells in hippocampus, but surprisingly, high-dose curcumin (10 mg/kg) did not effectively upregulate the proliferation or survival of newborn cells. Furthermore, hippocampal BDNF levels and phosphorylated CREB activity were elevated in only low-dose curcumin-treated mice. Passive avoidance testing revealed that low-dose curcumin increased cross-over latency times, indicating enhanced memory retention, and an in vitro study showed that low-concentration curcumin increased the proliferative activity of neural progenitor cells (NPCs) by upregulating NF1X levels. Collectively, our findings suggest that low-dose curcumin has neurogenic effects and that it may prevent age and neurodegenerative disease-related cognitive deficits.

The Implications of Microglial Regulation in Neuroplasticity-Dependent Stroke Recovery

Stroke causes varying degrees of neurological deficits, leading to corresponding dysfunctions. There are different therapeutic principles for each stage of pathological development. Neuroprotection is the main treatment in the acute phase, and functional recovery becomes primary in the subacute and chronic phases. Neuroplasticity is considered the basis of functional restoration and neurological rehabilitation after stroke, including the remodeling of dendrites and dendritic spines, axonal sprouting, myelin regeneration, synapse shaping, and neurogenesis. Spatiotemporal development affects the spontaneous rewiring of neural circuits and brain networks. Microglia are resident immune cells in the brain that contribute to homeostasis under physiological conditions. Microglia are activated immediately after stroke, and phenotypic polarization changes and phagocytic function are crucial for regulating focal and global brain inflammation and neurological recovery. We have previously shown that the development of neuroplasticity is spatiotemporally consistent with microglial activation, suggesting that microglia may have a profound impact on neuroplasticity after stroke and may be a key therapeutic target for post-stroke rehabilitation. In this review, we explore the impact of neuroplasticity on post-stroke restoration as well as the functions and mechanisms of microglial activation, polarization, and phagocytosis. This is followed by a summary of microglia-targeted rehabilitative interventions that influence neuroplasticity and promote stroke recovery.

Role of curcumin and its nanoformulations in the treatment of neurological diseases through the effects on stem cells

Curcumin from turmeric is a natural phenolic compound with a promising potential to regulate fundamental processes involved in neurological diseases, including inflammation, oxidative stress, protein aggregation, and apoptosis at the molecular level. In this regard, employing nanoformulation can improve curcumin efficiency by reducing its limitations, such as low bioavailability. Besides curcumin, growing data suggest that stem cells are a noteworthy candidate for neurodegenerative disorders therapy due to their anti-inflammatory, anti-oxidative, and neuronal-differentiation properties, which result in neuroprotection. Curcumin and stem cells have similar neurogenic features and can be co-administered in a cell-drug delivery system to achieve better combination therapeutic outcomes for neurological diseases. Based on the evidence, curcumin can induce the neuroprotective activity of stem cells by modulating their related signalling pathways. The present review is about the role of curcumin and its nanoformulations in the improvement of neurological diseases alone and through the effect on different categories of stem cells by discussing the underlying mechanisms to provide a roadmap for future investigations.

The Role of Green Tea Catechin Epigallocatechin Gallate (EGCG) and Mammalian Target of Rapamycin (mTOR) Inhibitor PP242 (Torkinib) in the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition that has physical and psychological consequences for patients. SCI is accompanied by scar formation and systemic inflammatory response leading to an intense degree of functional loss. The catechin, epigallocatechin gallate (EGCG), an active compound found in green tea, holds neuroprotective features and is known for its anti-inflammatory potential. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that exists in two functionally distinct complexes termed mTOR complex 1 and 2 (mTORC1; mTORC2). Inhibition of mTORC1 by rapamycin causes neuroprotection, leading to partial recovery from SCI. In this study the effects of EGCG, PP242 (an inhibitor of both complexes of mTOR), and a combination of EGCG and PP242 in SCI have been examined. It has been found that both EGCG and PP242 significantly improved sensory/motor functions following SCI. However, EGCG appeared to be more effective (BBB motor test, from 2 to 8 weeks after SCI, p = 0.019, p = 0.007, p = 0.006, p = 0.006, p = 0.05, p = 0.006, and p = 0.003, respectively). The only exception was the Von Frey test, where EGCG was ineffective, while mTOR inhibition by PP242, as well as PP242 in combination with EGCG, significantly reduced withdrawal latency starting from week three (combinatorial therapy (EGCG + PP242) vs. control at 3, 5, and 7 weeks, p = 0.011, p = 0.007, and p = 0.05, respectively). It has been found that EGCG was as effective as PP242 in suppressing mTOR signaling pathways, as evidenced by a reduction in phosphorylated S6 expression (PP242 (t-test, p < 0.0001) or EGCG (t-test, p = 0.0002)). These results demonstrate that EGCG and PP242 effectively suppress mTOR pathways, resulting in recovery from SCI in rats, and that EGCG acts via suppressing mTOR pathways.

Stem Cell-derived Extracellular Vesicles: A Promising Nano Delivery Platform to the Brain?

A very important cause of the frustration with drug therapy for central nervous system (CNS) diseases is the failure of drug delivery. The blood-brain barrier (BBB) prevents most therapeutic molecules from entering the brain while maintaining CNS homeostasis. Scientists are keen to develop new brain drug delivery systems to solve this dilemma. Extracellular vesicles (EVs), as a class of naturally derived nanoscale vesicles, have been extensively studied in drug delivery due to their superior properties. This review will briefly present current brain drug delivery strategies, including invasive and non-invasive techniques that target the brain, and the application of nanocarriers developed for brain drug delivery in recent years, especially EVs. The cellular origin of EVs affects the surface protein, size, yield, luminal composition, and other properties of EVs, which are also crucial in determining whether EVs are useful as drug carriers. Stem cell-derived EVs, which inherit the properties of parental cells and avoid the drawbacks of cell therapy, have always been favored by researchers. Thus, in this review, we will focus on the application of stem cell-derived EVs for drug delivery in the CNS. Various nucleic acids, proteins, and small-molecule drugs are loaded into EVs with or without modification and undergo targeted delivery to the brain to achieve their therapeutic effects. In addition, the challenges facing the clinical application of EVs as drug carriers will also be discussed. The directions of future efforts may be to improve drug loading efficiency and precise targeting.

Curcumin's mechanism of action against ischemic stroke: A network pharmacology and molecular dynamics study

Ischemic stroke (IS) is one of the major global causes of death and disability. Because blood clots block the neural arteries provoking ischemia and hypoxia in the brain tissue, IS results in irreversible neurological damage. Available IS treatments are currently limited. Curcumin has gained attention for many beneficial effects after IS, including neuroprotective and anti-inflammatory; however, its precise mechanism of action should be further explored. With network pharmacology, molecular docking, and molecular dynamics (MD), this study aimed to comprehensively and systematically investigate the potential targets and molecular mechanisms of curcumin on IS. We screened 1096 IS-related genes, 234 potential targets of curcumin, and 97 intersection targets. KEGG and GO enrichment analyses were performed on these intersecting targets. The findings showed that the treatment of IS using curcumin is via influencing 177 potential signaling pathways (AGE-RAGE signaling pathway, p53 signaling pathway, necroptosis, etc.) and numerous biological processes (the regulation of neuronal death, inflammatory response, etc.), and the AGE-RAGE signaling pathway had the largest degree of enrichment, indicating that it may be the core pathway. We also constructed a protein-protein interaction network and a component-target-pathway network using network pharmacology. From these, five key targets were screened: NFKB1, TP53, AKT1, STAT3, and TNF. To predict the binding conformation and intermolecular affinities of the key targets and compounds, molecular docking was used, whose results indicated that curcumin exhibited strong binding activity to the key targets. Moreover, 100 ns MD simulations further confirmed the docking findings and showed that the curcumin-protein complex could be in a stable state. In conclusion, curcumin affects multiple targets and pathways to inhibit various important pathogenic mechanisms of IS, including oxidative stress, neuronal death, and inflammatory responses. This study offers fresh perspectives on the transformation of curcumin to clinical settings and the development of IS therapeutic agents.

Immunomodulatory Therapeutic Effects of Curcumin on M1/M2 Macrophage Polarization in Inflammatory Diseases

BACKGROUND

Due to their plasticity, macrophages exert critical effects on both promoting and suppressing inflammatory processes. Pathologic inflammatory conditions are frequently correlated with dynamic alterations in macrophage activation, with classically activated M1 cells associated with the promotion and maintenance of inflammation and M2 cells being linked to the resolution or smouldering of chronic inflammation. Inflammation deputes a common feature of various chronic diseases and the direct involvement in the insurgence and development of these conditions. Macrophages participate in an autoregulatory loop characterizing the inflammatory process, as they produce a wide range of biologically active mediators that exert either deleterious or beneficial effects during the inflammation. Therefore, balancing the favorable ratios of M1/M2 macrophages can help ameliorate the inflammatory landscape of pathologic conditions. Curcumin is a component of turmeric with many pharmacological properties.

OBJECTIVE

Recent results from both in-vivo and in-vitro studies have indicated that curcumin can affect polarization and/or functions of macrophage subsets in the context of inflammation-related diseases. There is no comprehensive review of the impact of curcumin on cytokines involved in macrophage polarization in the context of inflammatory diseases. The present review will cover some efforts to explore the underlying molecular mechanisms by which curcumin modulates the macrophage polarization in distant pathological inflammatory conditions, such as cancer, autoimmunity, renal inflammation, stroke, atherosclerosis, and macrophage-driven pathogenesis.

RESULTS

The accumulation of the findings from in vitro and in vivo experimental studies suggests that curcumin beneficially influences M1 and M2 macrophages in a variety of inflammatory diseases with unfavorable macrophage activation.

CONCLUSION

Curcumin not only enhances anti-tumor immunity (via shifting M polarization towards M1 phenotype and/or up-regulation of M1 markers expression) but ameliorates inflammatory diseases, including autoimmune diseases (experimental autoimmune myocarditis and Behcet's disease), nephropathy, chronic serum sickness, stroke, and atherosclerosis.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Long-Circulation and Brain Targeted Isoliquiritigenin Micelle Nanoparticles: Formation, Characterization, Tissue Distribution, Pharmacokinetics and Effects for Ischemic Stroke

PURPOSE

We designed a novel isoliquiritigenin (ISL) loaded micelle prepared with DSPE-PEG2000 as the drug carrier modified with the brain-targeting polypeptide angiopep-2 to improve the poor water solubility and low bioavailability of ISL for the treatment of acute ischemic stroke.

METHODS

Thin film evaporation was used to synthesize the ISL micelles (ISL-M) modified with angiopep-2 as the brain targeted ligands. The morphology of the micelles was observed by the TEM. The particle size and zeta potential were measured via the nanometer particle size analyzer. The drug loading, encapsulation and in vitro release rates of micelles were detected by the HPLC. The UPLC-ESI-MS/MS methods were used to measure the ISL concentrations of ISL in plasma and main tissues after intravenous administration, and compared the pharmacokinetics and tissue distributions between ISL and ISL-M. In the MCAO mice model, the protective effects of ISL and ISL-M were confirmed via the behavioral and molecular biology experiments.

RESULTS

The results showed that the drug loading of ISL-M was 7.63 ± 2.62%, the encapsulation efficiency was 68.17 ± 6.23%, the particle size was 40.87 ± 4.82 nm, and the zeta potential was -34.23 ± 3.35 mV. The in vitro release experiments showed that ISL-M had good sustained-release effect and pH sensitivity. Compared with ISL monomers, the ISL-M could significantly prolong the in vivo circulation time of ISL and enhance the accumulation in the brain tissues. The ISL-M could ameliorate the brain injury induced by the MCAO mice via inhibition of cellular autophagy and neuronal apoptosis. There were no the cellular structural damages and other adverse effects for ISL-M on the main tissues and organs.

CONCLUSION

The ISL-M could serve as a promising and ideal drug candidate for the clinical application of ISL in the treatment of acute ischemic stroke.

Regulation of N6-methyladenosine (m6A) RNA methylation in microglia-mediated inflammation and ischemic stroke

N6-methyladenosine (m6A) is the most abundant post-transcription modification, widely occurring in eukaryotic mRNA and non-coding RNA. m6A modification is highly enriched in the mammalian brain and is associated with neurological diseases like Alzheimer’s disease (AD) and Parkinson’s disease (PD). Ischemic stroke (IS) was discovered to alter the cerebral m6A epi-transcriptome, which might have functional implications in post-stroke pathophysiology. Moreover, it is observed that m6A modification could regulate microglia’s pro-inflammatory and anti-inflammatory responses. Given the critical regulatory role of microglia in the inflammatory processes in the central nervous system (CNS), we speculate that m6A modification could modulate the post-stroke microglial inflammatory responses. This review summarizes the vital regulatory roles of m6A modification in microglia-mediated inflammation and IS. Stroke is associated with a high recurrence rate, understanding the relationship between m6A modification and stroke may help stroke rehabilitation and develop novel therapies in the future.

The action of curcumin against damage resulting from cerebral stroke: a systematic review

Stroke is the second leading cause of morbidity and mortality globally. Treatments for stroke are limited, and preventive treatments are scarce. Curcumin (CUR) has several biological effects, as described in the literature, which highlight its antioxidant and neuroprotective effects. Therefore, this qualitative systematic review aimed to investigate the effects of CUR on damage caused by stroke in rodent models. A systematic search was performed on three databases PubMed, Scopus, and Web of Science. In addition, the risk-of-bias and quality of the studies were assessed using SYRCLE and Collaborative Approach for Meta-Analysis and Review of Animal Data from Experimental Studies, respectively. The selection, inclusion, and exclusion criteria were established by the authors. At the end of our systematic search of the three databases, we found a total of 728 articles. After excluding duplicates and triplicates and reading the abstracts, keywords, and full texts, 53 articles were finally included in this systematic review. CUR exerts several beneficial effects against the damage caused by both ischemic and hemorrhagic stroke, via different pathways. However, because of its low bioavailability, Free-form CUR only exerted significant effects when it was administered at high concentrations. In contrast, when CUR was administered using nanostructured systems, positive responses were observed even at low concentrations. The mechanisms of action of CUR, free or in nanostructure, are extremely important for the recovery of injured brain tissue after a stroke; CUR has neuroprotective, antioxidant, anti-inflammatory, and anti-apoptotic effects and helps to maintain the integrity of the blood-brain barrier. Finally, we concluded that CUR presents an extremely important and significant response profile against the damage caused by stroke, making it a possible therapeutic candidate for individuals affected by this disease.

Ameliorating potential of curcumin and its analogue in central nervous system disorders and related conditions: A review of molecular pathways

Curcumin, isolated from turmeric (Curcuma longa L.) is one of the broadly studied phytomolecule owing to its strong antioxidant and anti-inflammatory potential and has been considered a promising therapeutic candidate in a wide range of disorders. Considering, its low bioavailability, different curcumin analogs have been developed to afford desired pharmacokinetic profile and therapeutic outcome in varied pathological states. Several preclinical and clinical studies have indicated that curcumin ameliorates mitochondrial dysfunction, inflammation, oxidative stress apoptosis-mediated neural cell degeneration and could effectively be utilized in the treatment of different neurodegenerative diseases. Hence, in this review, we have summarized key findings of experimental and clinical studies conducted on curcumin and its analogues with special emphasis on molecular pathways, viz. NF-kB, Nrf2-ARE, glial activation, apoptosis, angiogenesis, SOCS/JAK/STAT, PI3K/Akt, ERK1/2 /MyD88 /p38 MAPK, JNK, iNOS/NO, and MMP pathways involved in imparting ameliorative effects in the therapy of neurodegenerative disorders and associated conditions.

Polyphenols for the Treatment of Ischemic Stroke: New Applications and Insights

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Currently, the main therapeutic strategy involves the use of intravenous thrombolysis to restore cerebral blood flow to prevent the transition of the penumbra to the infarct core. However, due to various limitations and complications, including the narrow time window in which this approach is effective, less than 10% of patients benefit from such therapy. Thus, there is an urgent need for alternative therapeutic strategies, with neuroprotection against the ischemic cascade response after IS being one of the most promising options. In the past few decades, polyphenolic compounds have shown great potential in animal models of IS because of their high biocompatibility and ability to target multiple ischemic cascade signaling pathways, although low bioavailability is an issue that limits the applications of several polyphenols. Here, we review the pathophysiological changes following cerebral ischemia and summarize the research progress regarding the applications of polyphenolic compounds in the treatment of IS over the past 5 years. Furthermore, we discuss several potential strategies for improving the bioavailability of polyphenolic compounds as well as some essential issues that remain to be addressed for the translation of the related therapies to the clinic.

Mechanisms Underlying Curcumin-Induced Neuroprotection in Cerebral Ischemia

Ischemic stroke is the leading cause of death and disability worldwide, and restoring the blood flow to ischemic brain tissues is currently the main therapeutic strategy. However, reperfusion after brain ischemia leads to excessive reactive oxygen species production, inflammatory cell recruitment, the release of inflammatory mediators, cell death, mitochondrial dysfunction, endoplasmic reticulum stress, and blood-brain barrier damage; these pathological mechanisms will further aggravate brain tissue injury, ultimately affecting the recovery of neurological functions. It has attracted the attention of researchers to develop drugs with multitarget intervention effects for individuals with cerebral ischemia. A large number of studies have established that curcumin plays a significant neuroprotective role in cerebral ischemia via various mechanisms, including antioxidation, anti-inflammation, anti-apoptosis, protection of the blood-brain barrier, and restoration of mitochondrial function and structure, restoring cerebral circulation, reducing infarct volume, improving brain edema, promoting blood-brain barrier repair, and improving the neurological functions. Therefore, summarizing the results from the latest literature and identifying the potential mechanisms of action of curcumin in cerebral ischemia will serve as a basis and guidance for the clinical applications of curcumin in the future.