Ginkgolides and bilobalide protect BV2 microglia cells against OGD/reoxygenation injury by inhibiting TLR2/4 signaling pathways

Shuxuening Injection Inhibits Apoptosis and Reduces Myocardial Ischemia-Reperfusion Injury in Rats through PI3K/AKT Pathway

OBJECTIVE

To investigate the main components and potential mechanism of Shuxuening Injection (SXNI) in the treatment of myocardial ischemia-reperfusion injury (MIRI) through network pharmacology and in vivo research.

METHODS

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) and PharmMapper databases were used to extract and evaluate the effective components of Ginkgo biloba leaves, the main component of SXNI. The Online Mendelian Inheritance in Man (OMIM) and GeneCards databases were searched for disease targets and obtain the drug target and disease target intersections. The active ingredient-target network was built using Cytoscape 3.9.1 software. The STRING database, Metascape online platform, and R language were used to obtain the key targets and signaling pathways of the anti-MIRI effects of SXNI. In order to verify the therapeutic effect of different concentrations of SXNI on MIRI in rats, 60 rats were first divided into 5 groups according to random number table method: the sham operation group, the model group, SXNI low-dose (3.68 mg/kg), medium-dose (7.35 mg/kg), and high-dose (14.7 mg/kg) groups, with 12 rats in each group. Then, another 60 rats were randomly divided into 5 groups: the sham operation group, the model group, SXNI group (14.7 mg/kg), SXNI+LY294002 group, and LY294002 group, with 12 rats in each group. The drug was then administered intraperitoneally at body weight for 14 days. The main biological processes were validated using in vivo testing. Evans blue/triphenyltetrazolium chloride (TTC) double staining, hematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, enzyme-linked immunosorbent assay (ELISA), and Western blot analysis were used to investigate the efficacy and mechanism of SXNI in MIRI rats.

RESULTS

Eleven core targets and 30 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were selected. Among these, the phosphoinositide 3-kinase (PI3K)/ protein kinase B (AKT) pathway was closely related to SXNI treatment of MIRI. In vivo experiments showed that SXNI reduced the myocardial infarction area in the model group, improved rat heart pathological damage, and reduced the cardiomyocyte apoptosis rate (all P<0.01). After SXNI treatment, the p-PI3K/PI3K and p-AKT/AKT ratios as well as B-cell lymphoma-2 (Bcl-2) protein expression in cardiomyocytes were increased, while the Bax and cleaved caspase 3 protein expression levels were decreased (all P<0.05). LY294002 partially reversed the protective effect of SXNI on MIRI.

CONCLUSION

SXNI protects against MIRI by activating the PI3K/AKT signaling pathway.

Taming microglia: the promise of engineered microglia in treating neurological diseases

Microglia, the CNS-resident immune cells, are implicated in many neurological diseases. Nearly one in six of the world's population suffers from neurological disorders, encompassing neurodegenerative and neuroautoimmune diseases, most with dysregulated neuroinflammation involved. Activated microglia become phagocytotic and secret various immune molecules, which are mediators of the brain immune microenvironment. Given their ability to penetrate through the blood-brain barrier in the neuroinflammatory context and their close interaction with neurons and other glial cells, microglia are potential therapeutic delivery vehicles and modulators of neuronal activity. Re-engineering microglia to treat neurological diseases is, thus, increasingly gaining attention. By altering gene expression, re-programmed microglia can be utilized to deliver therapeutics to targeted sites and control neuroinflammation in various neuroinflammatory diseases. This review addresses the current development in microglial engineering, including genetic targeting and therapeutic modulation. Furthermore, we discuss limitations to the genetic engineering techniques and models used to test the functionality of re-engineered microglia, including cell culture and animal models. Finally, we will discuss future directions for the application of engineered microglia in treating neurological diseases.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Inflammation, Autoimmunity and Neurodegenerative Diseases, Therapeutics and Beyond

Neurodegenerative disease (ND) incidence has recently increased due to improved life expectancy. Alzheimer's (AD) or Parkinson's disease (PD) are the most prevalent NDs. Both diseases are poly genetic, multifactorial and heterogenous. Preventive medicine, a healthy diet, exercise, and controlling comorbidities may delay the onset. After the diseases are diagnosed, therapy is needed to slow progression. Recent studies show that local, peripheral and age-related inflammation accelerates NDs' onset and progression. Patients with autoimmune disorders like inflammatory bowel disease (IBD) could be at higher risk of developing AD or PD. However, no increase in ND incidence has been reported if the patients are adequately diagnosed and treated. Autoantibodies against abnormal tau, β amyloid and α- synuclein have been encountered in AD and PD and may be protective. This discovery led to the proposal of immune-based therapies for AD and PD involving monoclonal antibodies, immunization/ vaccines, pro-inflammatory cytokine inhibition and anti-inflammatory cytokine addition. All the different approaches have been analysed here. Future perspectives on new therapeutic strategies for both disorders are concisely examined.

Sodium salicylate ameliorates exercise-induced muscle damage in mice by inhibiting NF-kB signaling

BACKGROUND

Eccentric muscle contraction can cause muscle damage, which reduces the efficiency of exercise. Previous evidence suggested that Sodium salicylate (SS) could improve the repair of aged muscle. This study intends to investigate whether SS can impact skeletal muscle damage caused by eccentric exercise.

METHODS

Eccentric treadmill exercise was performed to induce muscle damage in mice. Plasma levels of muscle damage markers were estimated. RT-qPCR was employed for detecting mRNA levels of proinflammatory mediators in murine gastrocnemius muscle. Immunofluorescence staining of laminin/DAPI was utilized for quantifying centrally nucleated myofibers in the gastrocnemius muscle. Western blotting was implemented to examine protein levels of mitsugumin 53 (MG53), matrix metalloproteinase (MMP)-2/9, and NF-κB signaling-related markers.

RESULTS

SS administration reduced muscle damage marker production in the plasma and decreased the levels of proinflammatory mediators, MG53 and MMP-2/9 in mice after exercise. SS alleviated the severity of muscle damage in the gastrocnemius of mice after eccentric exercise. SS blocked NF-κB signaling pathway in the gastrocnemius muscle.

CONCLUSION

SS administration ameliorates skeletal muscle damage caused by eccentric exercise in the mouse model.

Oncogenic BRAFV600E induces microglial proliferation through extracellular signal-regulated kinase and neuronal death through c-Jun N-terminal kinase

Activating V600E in v-Raf murine sarcoma viral oncogene homolog B (BRAF) is a common driver mutation in cancers of multiple tissue origins, including melanoma and glioma. BRAFV600E has also been implicated in neurodegeneration. The present study aims to characterize BRAFV600E during cell death and proliferation of three major cell types of the central nervous system: neurons, astrocytes, and microglia. Multiple primary cultures (primary cortical mixed culture) and cell lines of glial cells (BV2) and neurons (SH-SY5Y) were employed. BRAFV600E and BRAFWT expression was mediated by lentivirus or retrovirus. Blockage of downstream effectors (extracellular signal-regulated kinase 1/2 and JNK1/2) were achieved by siRNA. In astrocytes and microglia, BRAFV600E induces cell proliferation, and the proliferative effect in microglia is mediated by activated extracellular signal-regulated kinase, but not c-Jun N-terminal kinase. Conditioned medium from BRAFV600E-expressing microglia induced neuronal death. In neuronal cells, BRAFV600E directly induces neuronal death, through c-Jun N-terminal kinase but not extracellular signal-regulated kinase. We further show that BRAF-related genes are enriched in pathways in patients with Parkinson's disease. Our study identifies distinct consequences mediated by distinct downstream effectors in dividing glial cells and in neurons following the same BRAF mutational activation and a causal link between BRAF-activated microglia and neuronal cell death that does not require physical proximity. It provides insight into a possibly important role of BRAF in neurodegeneration as a result of either dysregulated BRAF in neurons or its impact on glial cells.

Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy

Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system (CNS) and long-term illness consequences. They may be associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system. The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the neurotherapeutic management of long COVID. Ginkgo biloba leaf extract (EGb) contains several bioactive ingredients, e.g., bilobalide, quercetin, ginkgolides A-C, kaempferol, isorhamnetin, and luteolin. They have various pharmacological and medicinal effects, including memory and cognitive improvement. Ginkgo biloba, through its anti-apoptotic, antioxidant, and anti-inflammatory activities, impacts cognitive function and other illness conditions like those in long COVID. While preclinical research on the antioxidant therapies for neuroprotection has shown promising results, clinical translation remains slow due to several challenges (e.g., low drug bioavailability, limited half-life, instability, restricted delivery to target tissues, and poor antioxidant capacity). This review emphasizes the advantages of nanotherapies using nanoparticle drug delivery approaches to overcome these challenges. Various experimental techniques shed light on the molecular mechanisms underlying the oxidative stress response in the nervous system and help comprehend the pathophysiology of the neurological sequelae of SARS-CoV-2 infection. To develop novel therapeutic agents and drug delivery systems, several methods for mimicking oxidative stress conditions have been used (e.g., lipid peroxidation products, mitochondrial respiratory chain inhibitors, and models of ischemic brain damage). We hypothesize the beneficial effects of EGb in the neurotherapeutic management of long-term COVID-19 symptoms, evaluated using either in vitro cellular or in vivo animal models of oxidative stress.

Icariin protects cerebral neural cells from ischemia‑reperfusion injury in an in vitro model by lowering ROS production and intracellular calcium concentration

Ischemia is one of the major causes of stroke. The present study investigated the protection of cultured neural cells by icariin (ICA) against ischemia-reperfusion (I/R) injury and possible mechanisms underlying the protection. Neural cells were isolated from neonatal rats and cultured in vitro. The cells were subjected to oxygen-glucose deprivation and reoxygenation (OGD-R) as an I/R mimic to generate I/R injury, and were post-OGD-R treated with ICA. Following the treatments, cell viability, apoptosis, reactive oxygen species (ROS), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and Ca²⁺ concentration were assessed using Cell Counting Kit-8 assay, flow cytometry, CyQUANT™ LDH Cytotoxicity Assay, H₂DCFDA and SOD colorimetric activity kit. After OGD-R, considerable I/R injury was observed in the neural cells, as indicated by reduced cell viability, increased apoptosis and increased production of ROS and LDH (P<0.05). Cellular Ca²⁺ concentration was also increased, while SOD activity remained unchanged. Post-OGD-R ICA treatments increased cell viability up to 87.1% (P<0.05) and reduced apoptosis as low as 6.6% (P<0.05) in a concentration-dependent manner. The treatments also resulted in fewer ROS (P<0.05), lower extracellular LDH content (440.5 vs. 230.3 U/l; P<0.05) and reduced Ca²⁺ increase (P<0.05). These data suggest that ICA protects the neural cells from I/R injury in an in vitro model through antioxidation activity and maintaining cellular Ca²⁺ homeostasis. This function may be explored as a potential therapeutic strategy for ischemia-related diseases after further in vivo studies.

Selective ischemic-hemisphere targeting Ginkgolide B liposomes with improved solubility and therapeutic efficacy for cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury (CI/RI) remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies. One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier (BBB), which affects the intracerebral delivery of drugs. Ginkgolide B (GB), a major bioactive component in commercially available products of Ginkgo biloba, has been shown significance in CI/RI treatment by regulating inflammatory pathways, oxidative damage, and metabolic disturbance, and seems to be a candidate for stroke recovery. However, limited by its poor hydrophilicity and lipophilicity, the development of GB preparations with good solubility, stability, and the ability to cross the BBB remains a challenge. Herein, we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid (DHA) to obtain a covalent complex GB-DHA, which can not only enhance the pharmacological effect of GB, but can also be encapsulated in liposomes stably. The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion (MCAO) rats. Compared to the marketed ginkgolide injection, Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion. Low levels of reactive oxygen species (ROS) and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment, while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype, which modulate neuroinflammatory and angiogenesis. In addition, Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway. Thus, transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.

Glial Cells Response in Stroke

As the second-leading cause of death, stroke faces several challenges in terms of treatment because of the limited therapeutic interventions available. Previous studies primarily focused on metabolic and blood flow properties as a target for treating stroke, including recombinant tissue plasminogen activator and mechanical thrombectomy, which are the only USFDA approved therapies. These interventions have the limitation of a narrow therapeutic time window, the possibility of hemorrhagic complications, and the expertise required for performing these interventions. Thus, it is important to identify the contributing factors that exacerbate the ischemic outcome and to develop therapies targeting them for regulating cellular homeostasis, mainly neuronal survival and regeneration. Glial cells, primarily microglia, astrocytes, and oligodendrocytes, have been shown to have a crucial role in the prognosis of ischemic brain injury, contributing to inflammatory responses. They play a dual role in both the onset as well as resolution of the inflammatory responses. Understanding the different mechanisms driving these effects can aid in the development of therapeutic targets and further mitigate the damage caused. In this review, we summarize the functions of various glial cells and their contribution to stroke pathology. The review highlights the therapeutic options currently being explored and developed that primarily target glial cells and can be used as neuroprotective agents for the treatment of ischemic stroke.

TiO2-Nanowired Delivery of Chinese Extract of Ginkgo biloba EGb-761 and Bilobalide BN-52021 Enhanced Neuroprotective Effects of Cerebrolysin Following Spinal Cord Injury at Cold Environment

Military personnel during combat or peacekeeping operations are exposed to extreme climates of hot or cold environments for longer durations. Spinal cord injury is quite common in military personnel following central nervous system (CNS) trauma indicating a possibility of altered pathophysiological responses at different ambient temperatures. Our previous studies show that the pathophysiology of brain injury is exacerbated in animals acclimated to cold (5 °C) or hot (30 °C) environments. In these diverse ambient temperature zones, trauma exacerbated oxidative stress generation inducing greater blood-brain barrier (BBB) permeability and cell damage. Extracts of Ginkgo biloba EGb-761 and BN-52021 treatment reduces brain pathology following heat stress. This effect is further improved following TiO₂ nanowired delivery in heat stress in animal models. Several studies indicate the role of EGb-761 in attenuating spinal cord induced neuronal damages and improved functional deficit. This is quite likely that these effects are further improved following nanowired delivery of EGb-761 and BN-52021 with cerebrolysin-a balanced composition of several neurotrophic factors and peptide fragments in spinal cord trauma. In this review, TiO₂ nanowired delivery of EGb-761 and BN-52021 with nanowired cerebrolysin is examined in a rat model of spinal cord injury at cold environment. Our results show that spinal cord injury aggravates cord pathology in cold-acclimated rats and nanowired delivery of EGb-761 and BN-52021 with cerebrolysin significantly induced superior neuroprotection, not reported earlier.

Pestalotiopsis Diversity: Species, Dispositions, Secondary Metabolites, and Bioactivities

Pestalotiopsis species have gained attention thanks to their structurally complex and biologically active secondary metabolites. In past decades, several new secondary metabolites were isolated and identified. Their bioactivities were tested, including anticancer, antifungal, antibacterial, and nematicidal activity. Since the previous review published in 2014, new secondary metabolites were isolated and identified from Pestalotiopsis species and unidentified strains. This review gathered published articles from 2014 to 2021 and focused on 239 new secondary metabolites and their bioactivities. To date, 384 Pestalotiopsis species have been discovered in diverse ecological habitats, with the majority of them unstudied. Some may contain secondary metabolites with unique bioactivities that might benefit pharmacology.

JQ1 inhibits high glucose-induced migration of retinal microglial cells by regulating the PI3K/AKT signaling pathway

Diabetic retinopathy (DR) is one of the main leading causes of visual impairment worldwide. The current study elucidates the role of JQ1 in DR. A diabetic model was constructed by STZ injection and a high-fat diet. After establishment of the diabetic model, rats were assigned to treatment groups: 1) control, 2) diabetic model, and 3) diabetic+JQ1 model. In vitro Transwell and wound-healing assays were used to measure BV2 cell viability by stimulation with low glucose and high glucose with or without JQ1 and 740Y-P. Pathological methods were used to analyze DR, and Western blotting was used to analyze protein expression. Identification of enriched pathways in DR was performed by bioinformatics. Histopathological examination demonstrated that JQ1 rescued the loss of retinal cells and increased the thickness of retinal layers in diabetic rats. JQ1 attenuated high glucose-stimulated BV2 microglial motility and migration. The bioinformatics analysis implied that the Pl3K-Akt signaling pathway was enriched in DR. JQ1 decreased the phosphorylation of PI3K and AKT as well as the immunostaining of PI3K in BV2 cells. 740Y-P (a PI3K agonist) significantly reversed the decrease in p-PI3K and p-AK in BV2 cells. Additionally, JQ1 decreased the protein expression of p-PI3K, p-AKT, and MMP2/9 and immunostaining of PI3K in retinal tissues of rats. JQ1 suppresses the PI3K/Akt cascade by targeting MMP expression, thus decreasing the viability and invasion capacity of retinal microglia, suggesting an interesting treatment target for DR.

CB1 as a novel target for Ginkgo biloba's terpene trilactone for controlling chemotherapy-induced peripheral neuropathy (CIPN)

The application of antineoplastic chemotherapeutic agents causes a common side effect known as chemotherapy-induced peripheral neuropathy (CIPN) that leads to reducing the quality of patient's life. This research involves the performance of molecular docking and molecular dynamic (MD) simulation studies to explore the impact of terpenoids of Ginkgo biloba on the targets (CB-1, TLR4, FAAH-1, COX-1, COX-2) that can significantly affect the controlling of CIPN's symptoms. According to the in-vitro and in-vivo investigations, terpenoids, particularly ginkgolides B, A, and bilobalide, can cause significant effects on neuropathic pain. The molecular docking results disclosed the tendency of our ligands to interact with mainly CB1 and FAAH-1, as well as partly with TLR4, throughout their interactions with targets. Terpene trilactone can exhibit a lower rate of binding energy than CB1's inhibitor (7dy), while being precisely located in the CB1's active site and capable of inducing stable interactions by forming hydrogen bonds. The analyses of MD simulation proved that ginkgolide B was a more suitable activator and inhibitor for CB1 and TLR4, respectively, when compared to bilobalide and ginkgolide A. Moreover, bilobalide is capable of inhibiting FAAH-1 more effectively than the two other ligands. According to the analyses of ADME, every three ligands followed the Lipinski's rule of five. Considering these facts, the exertion of three ligands is recommended for their anti-inflammatory, neuroprotective, and anti-nociception influences caused by primarily activating CB1 and inhibiting FAAH-1 and TLR4; in this regard, these compounds can stand as potential candidates for the control and treatment of CIPN's symptoms.

Elevated serum IL-10 is associated with severity of neonatal encephalopathy and adverse early childhood outcomes

BACKGROUND

Neonatal encephalopathy (NE) contributes substantially to child mortality and disability globally. We compared cytokine profiles in term Ugandan neonates with and without NE, with and without perinatal infection or inflammation and identified biomarkers predicting neonatal and early childhood outcomes.

METHODS

In this exploratory biomarker study, serum IL-1α, IL-6, IL-8, IL-10, TNFα, and VEGF (<12 h) were compared between NE and non-NE infants with and without perinatal infection/inflammation. Neonatal (severity of NE, mortality) and early childhood (death or neurodevelopmental impairment to 2.5 years) outcomes were assessed. Predictors of outcomes were explored with multivariable linear and logistic regression and receiver-operating characteristic analyses.

RESULTS

Cytokine assays on 159 NE and 157 non-NE infants were performed; data on early childhood outcomes were available for 150 and 129, respectively. NE infants had higher IL-10 (p < 0.001), higher IL-6 (p < 0.017), and lower VEGF (p < 0.001) levels. Moderate and severe NE was associated with higher IL-10 levels compared to non-NE infants (p < 0.001). Elevated IL-1α was associated with perinatal infection/inflammation (p = 0.013). Among NE infants, IL-10 predicted neonatal mortality (p = 0.01) and adverse early childhood outcome (adjusted OR 2.28, 95% CI 1.35-3.86, p = 0.002).

CONCLUSIONS

Our findings support a potential role for IL-10 as a biomarker for adverse outcomes after neonatal encephalopathy.

IMPACT

Neonatal encephalopathy is a common cause of child death and disability globally. Inflammatory cytokines are potential biomarkers of encephalopathy severity and outcome. In this Ugandan health facility-based cohort, neonatal encephalopathy was associated with elevated serum IL-10 and IL-6, and reduced VEGF at birth. Elevated serum IL-10 within 12 h after birth predicted severity of neonatal encephalopathy, neonatal mortality, and adverse early childhood developmental outcomes, independent of perinatal infection or inflammation, and provides evidence to the contribution of the inflammatory processes. Our findings support a role for IL-10 as a biomarker for adverse outcomes after neonatal encephalopathy in a sub-Saharan African cohort.

Carnosol suppresses microglia cell inflammation and apoptosis through PI3K/AKT/mTOR signaling pathway

Ischemic stroke is the most common type of acute cerebrovascular disease. Carnosol is a polyphenol compound extracted from rosemary. This study aimed to explore the effects of carnosol on the oxygen-glucose deprivation (OGD) treated BV2 microglia cells. MTT and EdU assays were used to detect the cell viability and proliferation. Flow cytometry was conducted to measure the apoptosis rates. Additionally, the protein expression was determined by western blot. The inflammatory factors and antioxidant indexes were detected by corresponding kits. Carnosol promoted the proliferation and inhibited the apoptosis of the OGD treated BV2 cells. What's more, the protein expressions of PCNA and Bcl-2 were up-regulated, the Bax expression was down-regulated after carnosol treatment. In addition, carnosol decreased the levels of MDA, LPO, TNF-α, IL-1β and IL-6, and increased the levels of GSH, SOD, IL-4 and IL-10 in the OGD treated BV2 cells. Furthermore, the PI3K/AKT/mTOR signaling pathway was activated after carnosol treatment and inhibition of the PI3K/AKT/mTOR signaling pathway reversed the carnosol effects. Carnosol promotes the proliferation, inhibits the apoptosis, relieves the oxidative damage and inflammation of OGD treated cells through regulating the PI3K/AKT/mTOR signaling pathway.

Overexpression of microRNA-381-3p ameliorates hypoxia/ischemia-induced neuronal damage and microglial inflammation via regulating the C-C chemokine receptor type 2 /nuclear transcription factor-kappa B axis

microRNAs, as small endogenous RNAs, influence umpteen sophisticated cellular biological functions regarding neurodegenerative and cerebrovascular diseases. Here, we interrogated miR-381-3p’s influence on BV2 activation and neurotoxicity in ischemic and hypoxic environment. Oxygen-glucose deprivation (OGD) was adopted to induce microglial activation and HT-22 neuron damage. Quantitative polymerase chain reaction (qRT-PCR) was taken to check miR-381-3p expression in OGD-elicited BV2 cells and HT-22 neurons. It transpired that miR-381-3p expression was lowered in BV2 cells and HT-22 cells elicited by OGD. miR-381-3p up-regulation remarkably hampered inflammatory mediator expression in BV2 cells induced by OGD and weakened HT22 neuron apoptosis. In vivo, miR-381-3p expression was abated in HI rats’ ischemic lesions, and miR-381-3p up-regulation could ameliorate inflammation and neuron apoptosis in their brain. C-C chemokine receptor type 2 (CCR2) was identified as the downstream target of miR-381-3p, and miR-381-3p suppressed the CCR2/NF-κB pathway to mitigate microglial activation and neurotoxicity. Therefore, we believed that miR-381-3p overexpression exerts anti-inflammation and anti-apoptosis in ischemic brain injury by targeting CCR2

Bilobalide: A review of its pharmacology, pharmacokinetics, toxicity, and safety

Bilobalide is a natural sesquiterpene trilactone from Ginkgo biloba leaves. It has good water solubility and is widely used in food and pharmaceutical fields. In the last decade, a plethora of studies on the pharmacological activities of bilobalide has been conducted and demonstrated that bilobalide possessed an extensive range of pharmacological activities such as neuroprotective, antioxidative, antiinflammatory, anti-ischemic, and cardiovascular protective activities. Pharmacokinetic studies indicated that bilobalide may have the characteristics of rapid absorption, good bioavailability, wide distribution, and slow elimination. This review aims to summarize the advances in pharmacological, pharmacokinetics, toxicity, and safety studies of bilobalide in the last decade with an emphasis on its neuroprotective and antiinflammatory activities, to provide researchers with the latest information and point out the limitations of relevant research at the current stage and the aspects that should be strengthened in future research.

Glial Cells as Therapeutic Approaches in Brain Ischemia-Reperfusion Injury

Ischemic stroke is the second cause of mortality and the first cause of long-term disability constituting a serious socioeconomic burden worldwide. Approved treatments include thrombectomy and rtPA intravenous administration, which, despite their efficacy in some cases, are not suitable for a great proportion of patients. Glial cell-related therapies are progressively overcoming inefficient neuron-centered approaches in the preclinical phase. Exploiting the ability of microglia to naturally switch between detrimental and protective phenotypes represents a promising therapeutic treatment, in a similar way to what happens with astrocytes. However, the duality present in many of the roles of these cells upon ischemia poses a notorious difficulty in disentangling the precise pathways to target. Still, promoting M2/A2 microglia/astrocyte protective phenotypes and inhibiting M1/A1 neurotoxic profiles is globally rendering promising results in different in vivo models of stroke. On the other hand, described oligodendrogenesis after brain ischemia seems to be strictly beneficial, although these cells are the less studied players in the stroke paradigm and negative effects could be described for oligodendrocytes in the next years. Here, we review recent advances in understanding the precise role of mentioned glial cell types in the main pathological events of ischemic stroke, including inflammation, blood brain barrier integrity, excitotoxicity, reactive oxygen species management, metabolic support, and neurogenesis, among others, with a special attention to tested therapeutic approaches.

Neuroprotective effects of Ginkgolide B in focal cerebral ischemia through selective activation of prostaglandin E2 receptor EP4 and the downstream transactivation of epidermal growth factor receptor

The present study was undertaken to identify whether prostaglandin E2 receptor is the potential receptor/binding site for Ginkgolide A, Ginkgolide B, Ginkgolide K, and Bilobalide, the four main ingredients of the Ginkgo biloba L., leaves. Using functional assays, we identified EP4, coupled with Gs protein, as a target of Ginkgolide B. In human neuroblastoma SH-SY5Y cells suffered from oxygen-glucose deprivation/reperfusion, Ginkgolide B-activated PKA, Akt, and ERK1/2 as well as Src-mediated transactivation of epidermal growth factor receptor. These resulted in downstream signaling pathways, which enhanced cell survival and inhibited apoptosis. Knockdown of EP4 prevented Ginkgolide B-mediated Src, epidermal growth factor receptor (EGFR), Akt, and ERK1/2 phosphorylation and neuroprotective effects. Moreover, Src inhibitor prevented Ginkgolide B-mediated EGFR transactivation and the downstream Akt and ERK1/2 activation, while the phosphorylation of PKA induced by Ginkgolide B was not affected, indicating Ginkgolide B might transactivate EGFR in a ligand-independent manner. EP4 knockdown in a rat middle cerebral artery occlusion (MCAO) model prevented Ginkgolide B-mediated infarct size reduction and neurological assessment improvement. At the same time, the increased expressions of p-Akt, p-ERK1/2, p-PKA, p-Src, and p-EGFR and the deceased expression of cleaved capases-3 induced by Ginkgolide B in cerebral cortex were blocked due to EP4 knockdown. In conclusion, Ginkgolide B exerts neuroprotective effects in rat MCAO model through the activation of EP4 and the downstream transactivation of EGFR.

Baicalin and Geniposide Inhibit Polarization and Inflammatory Injury of OGD/R-Treated Microglia by Suppressing the 5-LOX/LTB4 Pathway

Cerebral ischemia causes severe neurological disorders and neuronal dysfunction. Baicalin (BC), geniposide (GP), and their combination (BC/GP) have been shown to inhibit post-ischemic inflammatory injury by inhibiting the 5-LOX/CysLTs pathway. The aims of this study were to observe the inhibitory effects of BC/GP on the activation of microglial cells induced by oxygen glucose deprivation and reoxygenation (OGD/R) and to investigate whether the 5-LOX/LTB4 pathway was involved in these effects. Molecular docking showed that BC and GP exhibited considerable binding activity with LTB4 synthase LTA4H. BV-2 microglia were transfected with a 5-LOX overexpression lentiviral vector, and then OGD/R was performed. The effects of different concentrations of BC, GP, and BC/GP (6.25 μM, 12.5 μM, and 25 μM) on cell viability and apoptosis of microglia were evaluated by MTT and flow cytometry. The expression of TNF-α, IL-1β, NF-κB, and pNF-κB also was measured by ELISA, Western blots and immunofluorescence. Western blots and qRT-PCR analysis were used to determine the levels of CD11b, CD206, and 5-LOX pathway proteins. Results showed that BC, GP, and BC/GP reduced the apoptosis caused by OGD/R in a dose-dependent manner, and cell viability was significantly increased at a concentration of 12.5 μM. OGD/R significantly increased the release of TNF-α, IL-1β, NF-κB, pNF-κB, and CD11b. These effects were suppressed by BC, GP, and BC/GP, and the OGD/R-induced transfer of NF-κB p65 from the ctytoplasm to the nucleus was inhibited in microglia. Interestingly, the LTB4 inhibitor, U75302, exhibited the same effect. Also, BC, GP, and BC/GP significantly reduced the expression of 5-LOX pathway proteins. These results demonstrated that BC/GP inhibited OGD/R-induced polarization in BV2 microglia by regulating the 5-LOX/LTB4 signaling pathways and attenuating the inflammatory response. Our results supported the theoretical basis for additional in-depth study of the function of BC/GP and the value of determining its unique target, which might provide a new therapeutic strategy for ischemic cerebrovascular disease.

Bilobalide Enhances AMPK Activity to Improve Liver Injury and Metabolic Disorders in STZ-Induced Diabetes in Immature Rats via Regulating HMGB1/TLR4/NF-κB Signaling Pathway

This study was aimed at examining the effect and underlying mechanisms of bilobalide (BB) on hepatic injury in streptozotocin- (STZ-) induced diabetes mellitus (DM) in immature rats. Immature rats (one day old) were randomly divided into five groups: group I, control nondiabetic rats; group II, STZ-induced, untreated diabetic rats; groups III/IV/V, STZ-induced and BB-treated diabetic rats, which were intraperitoneally injected with BB (2.5 mg/kg, 5 mg/kg, or 10 mg/kg) after 3 days followed by STZ treatment. We observed that BB improved the histopathological changes and maintained normal glucose metabolism, blood lipid, and liver function indicators, such as fasting blood glucose, obesity index, HbA1c, HOMA-IR, fast serum insulin, adiponectin, total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), aspartate transaminase (AST), and alanine transaminase (ALT) in STZ-induced DM in immature rats by a biochemical analyzer or ELISA. Meanwhile, Western blot analysis showed that in STZ-induced DM immature rats, BB decreased the expression of apoptosis-related proteins Bax, cleaved caspase-3, and cleaved caspase-9 while enhancing the Bcl-2 expression; BB downregulated the expression of ACC related to fat anabolism, while upregulating the expression of CPT-1 related to fat catabolism. Strikingly, treatment with BB significantly increased the expression of AMPKα1 as well as inhibited HMGB1, TLR4, and p-P65 expression in hepatic tissues of immature DM rats. AMPK inhibitor (compound C, CC) cotreated with BB undermined the protective effect of BB on the liver injury. The results of the present study suggested BB may have a significant role in alleviating liver damage in the STZ-induced immature DM rats.

The therapeutic effects of ginkgolides in Guillain-Barré syndrome and experimental autoimmune neuritis

BACKGROUND

Guillain-Barré syndrome (GBS) is an acquired immune-mediated inflammatory peripheral neuropathy. The immune regulation of ginkgolides have been revealed in recent years. We herein investigate the potential therapeutic effects of ginkgolides both on GBS and its animal model, experimental autoimmune neuritis (EAN).

METHODS

EAN in C57BL/6 mice induced by subcutaneous injection with peripheral nerve myelin P0 protein peptide 180-199 (P0 peptide) were treated with ginkgolides at three different doses. GBS patients were randomly divided into two groups, the experimental group and the control group. The experimental group were treated with ginkgolides as soon as diagnosed.

RESULTS

Our data indicated that ginkgolides administration daily ameliorated the score of EAN and delayed the peak of disease in EAN mice. Ginkgolides also down-regulated the proportions of T helper (Th) 17 cells in EAN spleens. Furthermore, we also found that administration of ginkgolides significantly decreased the levels of interferon (IFN)-γ and interleukin-12 (IL)-12 in GBS patients.

CONCLUSIONS

Our results suggested that ginkgolides ameliorated the clinical score of EAN through down-regulating the proportions of Th 17 cells. Ginkgolides also suppressed inflammation response by decreasing pro-inflammatory cytokines IFN-γ and IL-12, suggesting ginkgolides had potential therapeutic effects on GBS patients and EAN in the future.

Chip-based serum proteomics approach to reveal the potential protein markers in the sub-acute stroke patients receiving the treatment of Ginkgo Diterpene Lactone Meglumine Injection

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. is a kind of traditional Chinese medicinal material with a long history. Its main active ingredients, ginkgolides, can be used for the treatment of stroke and other cardio-cerebrovascular diseases. Ginkgo Diterpene Lactone Meglumine Injection (GDLI), a modernized TCM, has attracted much attention because of its neuroprotective and anti-inflammatory properties.

AIM OF THE STUDY

To uncover the effects of GDLI on ischemic stroke patients, as well as the underlying biomarkers involved in sub-acute stroke.

MATERIALS AND METHODS

We used a state-of-the-art targeted proteomics chip to investigate the association between numerous serum proteins (1101 proteins) and the sub-acute phase post-ischemic stroke. Then, the relative proteins of anti-apoptosis, anticoagulant, and neuroprotection of GDLI were verified in animal models.

RESULTS

Compared with the serum from healthy volunteers, we identified 15 up-regulated proteins and 26 down-regulated proteins (FC ≥ 1.5) involved in inflammatory response, immune response, and nervous system development in the sub-acute ischemic stroke. The pro-inflammatory proteins, such as IL17, MSP-R, G-CSF-R, TLR3, MIP-3β, TNFRSF19, and TNFRSF12, were significantly increased in serum, illustrating that the chronic inflammatory state was evident in the sub-acute stage of ischemic stroke. However, the common pro-inflammatory proteins, such as IL-1β, IL-6, IL-8, TNF-α, IFN-γ, and IL-10, known to be up-regulated in acute stroke, had close or lightly lower levels than healthy humans (FC ≥ 1.5, P > 0.05). And some cytokines (IL3, CCL13, TNFRSF3, IL10 R beta, HLA-A, IL-1 F8/FIL1 eta, TNFRSF8, CCL18) were also markedly down-regulated in the sub-acute phase of stroke. These proteins are highly associated with the onset of stroke-induced immunosuppression and post-stroke infection. Moreover, we noticed that Ginkgo Diterpene Lactone Meglumine Injection (GDLI) treatment for 14 days was helpful to the recovery of patients in the subacute period. After the treatment of GDLI, it was observed that several inflammatory cytokines (i.e. IL-17 and IL-28A), chemokine (i.e. CCL14), and Coagulation Factor III were reduced. Meanwhile, the anti-inflammatory cytokines (IL-10 R alpha, GREMLIN, and Activin C) and neurotrophic factors (Neurturin and IGFBP2) were found to be up-regulated in stroke patients through self-control observation. Finally, we identified the IGFBP2 as a novel marker in the animal models.

CONCLUSIONS

In summary, the potential markers in sub-acute stroke patients were highly different from known protein markers in the acute phase of ischemic stroke. The serum protein IGFBP2 could be novel biomarkers for the treatment of GDLI in sub-acute stroke patients. Our present findings provide an innovative insight into the novel treatment of GDLI in ischemic stroke therapy.

Inhibition of microglial receptor-interacting protein kinase 1 ameliorates neuroinflammation following cerebral ischaemic stroke

Microglia are rapidly activated following ischaemic stroke and participate in the induction of neuroinflammation, which exacerbates the injury of ischaemic stroke. However, the mechanisms regulating ischaemic microglia remain unclear. In the present study, middle cerebral artery occlusion and oxygen and glucose deprivation models were established for in vivo and vitro monitoring of experimental stroke. We applied recombinant human thioredoxin‐1 (rhTrx‐1) and Necrostatin‐1 (Nec‐1, inhibitor of RIPK1) to examine the role of receptor‐interacting protein kinase 1 (RIPK1) in the development of inflammation in ischaemic microglia via explored the inflammatory responses and the associated mechanisms. Molecular docking results indicated that rhTrx‐1 could directly bind to RIPK1. In vivo and vitro data revealed that rhTrx‐1 reduced necroptosis, mitochondrial membrane potential damage, reactive oxygen species accumulation and NLR Family, pyrin domain‐containing 3 protein (NLRP3) inflammasome activation and regulated the microglial M1/M2 phenotypic changes by inhibiting RIPK1 expression in ischaemic microglia. Consistent with these findings, further in vivo experiments revealed that rhTrx‐1 treatment attenuated cerebral ischaemic injury by inhibiting the inflammatory response. Our data demonstrated the role of RIPK1 in microglia‐induced neuroinflammation following cerebral ischaemia. Administration of rhTrx‐1 provides neuroprotection in ischaemic stroke‐induced microglial neuroinflammation by inhibiting RIPK1 expression.

Alzheimer's disease: natural products as inhibitors of neuroinflammation

Alzheimer’s disease (AD) is the most common form of dementia and affects 44 million people worldwide. New emerging evidence from pre-clinical and clinical investigations shows that neuroinflammation is a major pathological component of AD suggesting that anti-inflammatory strategies are important in delaying the onset or slowing the progression of the disease. However, efforts to employ current anti-inflammatory agents in AD clinical trials have produced limited success. Consequently, there is a need to explore anti-inflammatory natural products, which target neuroinflammatory pathways relevant to AD pathogenesis. This review summarises important druggable molecular targets of neuroinflammation and presents classes of anti-neuroinflammatory natural products with potentials for preventing and reducing symptoms of AD.

bFGF promotes neurological recovery from neonatal hypoxic-ischemic encephalopathy by IL-1β signaling pathway-mediated axon regeneration

INTRODUCTION

Neonatal hypoxia-ischemic brain damage (HIBD) can lead to serious neuron damage and dysfunction, causing a significant worldwide health problem. bFGF as a protective reagent promotes neuron repair under hypoxia/ischemia (HI). However, how bFGF and downstream molecules were regulated in HI remains elusive.

METHODS

We established an in vitro HI model by culturing primary cortical neurons and treated with oxygen-glucose deprivation (OGD). We suppressed the expression of bFGF by using siRNA (small interfering RNA) interference to detect the neuronal morphological changes by immunofluorescence staining. To determine the potential mechanisms regulated by bFGF, the change of downstream molecular including IL-1β was examined in bFGF knockdown condition. IL-1β knockout (KO) rats were generated using CRISPR/Cas9-mediated technologies. We used an accepted rat model of HI, to assess the effect of IL-1β deletion on disease outcomes and carried out analysis on the behavior, histological, cellular, and molecular level.

RESULTS

We identified that OGD can induce endogenous expression of bFGF. Both OGD and knockdown of bFGF resulted in reduction of neuron numbers, enlarged cell body and shortened axon length. We found molecules closely related to bFGF, such as interleukin-1β (IL-1β). IL-1β was up-regulated after bFGF interference under OGD conditions, suggesting complex signaling between bFGF and OGD-mediated pathways. We found HI resulted in up-regulation of IL-1β mRNA in cortex and hippocampus. IL-1β KO rats markedly attenuated the impairment of long-term learning and memory induced by HI. Meanwhile, IL-1β^-/- (KO, homozygous) group showed better neurite growth and less apoptosis in OGD model. Furthermore, serine/threonine protein kinase (AKT1) mRNA and protein expression was significantly up-regulated in IL-1β KO rats.

CONCLUSIONS

We showed that IL-1β-mediated axon regeneration underlie the mechanism of bFGF for the treatment of HIBD in neonatal rats. Results from this study would provide insights and molecular basis for future therapeutics in treating HIBD.

Role of the neurovascular unit in the process of cerebral ischemic injury

Cerebral ischemic injury exhibits both high morbidity and mortality worldwide. Traditional research of the pathogenesis of cerebral ischemic injury has focused on separate analyses of the involved cell types. In recent years, the neurovascular unit (NVU) mechanism of cerebral ischemic injury has been proposed in modern medicine. Hence, more effective strategies for the treatment of cerebral ischemic injury may be provided through comprehensive analysis of brain cells and the extracellular matrix. However, recent studies that have investigated the function of the NVU in cerebral ischemic injury have been insufficient. In addition, the metabolism and energy conversion of the NVU depend on interactions among multiple cell types, which make it difficult to identify the unique contribution of each cell type. Therefore, in the present review, we comprehensively summarize the regulatory effects and recovery mechanisms of four major cell types (i.e., astrocytes, microglia, brain-microvascular endothelial cells, and neurons) in the NVU under cerebral ischemic injury, as well as discuss the interactions among these cell types in the NVU. Furthermore, we discuss the common signaling pathways and signaling factors that mediate cerebral ischemic injury in the NVU, which may help to provide a theoretical basis for the comprehensive elucidation of cerebral ischemic injury.

Role of Ginkgolides in the Inflammatory Immune Response of Neurological Diseases: A Review of Current Literatures

The inflammatory immune response (IIR) is a physiological or excessive systemic response, induced by inflammatory immune cells according to changes in the internal and external environments. An excessive IIR is the pathological basis for the generation and development of neurological diseases. Ginkgolides are one of the important medicinal ingredients in Ginkgo biloba. Many studies have verified that ginkgolides have anti-platelet-activating, anti-apoptotic, anti-oxidative, neurotrophic, and neuroimmunomodulatory effects. Inflammatory immunomodulation is mediated by inhibition of the mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. They also inhibit the platelet-activating factor (PAF)-mediated signal transduction to attenuate the inflammatory response. Herein, we reviewed the studies on the roles of ginkgolides in inflammatory immunomodulation and suggested its potential role in novel treatments for neurological diseases.

Bilobalide protects against ischemia/reperfusion-induced oxidative stress and inflammatory responses via the MAPK/NF-휅B pathways in rats

Background

Clinically, skeletal muscle ischemia/reperfusion injury is a life-threatening syndrome that is often caused by skeletal muscle damage and is characterized by oxidative stress and inflammatory responses. Bilobalide has been found to have antioxidative and anti-inflammatory effects. However, it is unclear whether bilobalide can protect skeletal muscle from ischemia/reperfusion injury.

Methods

The effects of bilobalide on ischemia/reperfusion-injured skeletal muscle were investigated by performing hematoxylin and eosin staining and assessing the wet weight/dry weight ratio of muscle tissue. Then, we measured lipid peroxidation, antioxidant activity and inflammatory cytokine levels. Moreover, Western blotting was conducted to examine the protein levels of MAPK/NF-휅B pathway members.

Results

Bilobalide treatment could protected hind limb skeletal muscle from ischemia/reperfusion injury by alleviating oxidative stress and inflammatory responses via the MAPK/NF-휅B pathways.

Conclusions

Bilobalide may be a promising drug for I/R-injured muscle tissue. However, the specific mechanisms for the protective effects still need further study.

Ginkgolide B attenuates myocardial infarction-induced depression-like behaviors via repressing IL-1β in central nervous system

Depression is common in patients with myocardial infarction (MI), attributing to worse outcomes. Inflammatory response in the central nervous system (CNS) is considered to be a potential mechanism underlying MI induced depression. Our former research demonstrated Ginkgo biloba extract played an important role in the repression of hippocampus inflammation in heart failure mice with depressive behaviors. This study was designed to investigate the effect of Ginkgolide B (GB) on MI-induced depression-like behaviors in post MI mice. After MI surgery induced by coronary ligation, MI mice behaved depressingly, detected by open field test (OFT) and the sucrose preference test (SPT), which was reserved by GB treatment. Meanwhile, the reduction of 5-HT and increase of interleukin 1 beta (IL-1β) in median raphe nucleus and cortex indicated potential mechanisms underlying MI-induced depression-like behaviors, which were significantly reserved by GB treatment. Moreover, the consistent variation of IL-1β and phospho-STAT3 expression in brain tissues, indicated a role of STAT3 pathway in IL-1β production and anti-inflammatory effect of GB. In conclusion, GB has great benefits in effective treatment for depression post MI through reducing the levels of proinflammatory cytokines via STAT3 pathway, implicating potential effects in improving depression status in patients with MI.

The therapeutic potential of bilobalide on experimental autoimmune encephalomyelitis (EAE) mice

Inflammatory demyelination in the central nervous system (CNS) is a hallmark of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Besides MS disease-modifying therapy, targeting myelin sheath protection/regeneration is currently a hot spot in the treatment of MS. Here, we attempt to explore the therapeutic potential of Bilobalide (BB) for the myelin protection/regeneration in EAE model. The results showed that BB treatment effectively prevented worsening and demyelination of EAE, accompanied by the inhibition of neuroinflammation that should be closely related to T cell tolerance and M2 macrophages/microglia polarization. BB treatment substantially inhibited the infiltration of T cells and macrophages, thereby alleviating the enlargement of neuroinflammation and the apoptosis of oligodendrocytes in CNS. The accurate mechanism of BB action and the feasibility of clinical application in the prevention and treatment of demyelination remain to be further explored.

Characterising lipoteichoic acid as an in vitro model of acute neuroinflammation

Toll-like receptor 2 (TLR2) is a primary sensor for pathogens, including those derived from gram-positive bacteria. It can also mediate the effects of endogenous inflammatory signals such as β-amyloid peptide (Aβ), thus promoting the microglial activation and subsequent neuronal dysfunction, characteristic of chronic neuroinflammatory conditions. More recently, a role for TLR2 has been proposed in the pathogenesis of disorders associated with acute inflammation, including anxiety and depression. The current study aims to characterise the acute effects of the TLR2 agonist lipoteichoic acid (LTA) on microglial activation and neuronal integrity, and to evaluate the influence of LTA exposure on sensitivity to the inflammation and neuronal dysfunction associated with Aβ. Using BV2 and N2a cells as an in vitro model, we highlight that acute exposure to LTA robustly promotes inflammatory cytokine and nitric oxide (NO) production in microglia but also in neurons, similar to that reported under longer-term and chronic inflammatory conditions. Moreover, we find that exposure to LTA can enhance sensitivity to subthreshold Aβ, promoting an 'M1'-like phenotype in microglia and provoking dysregulation of neuronal activity in acute hippocampal slices. Anti-inflammatory agents, including mimetics of brain-derived neurotrophic factor (BDNF), have proven effective at alleviating chronic neuroinflammatory complications. We further examined the effects of 7,8,3-trihydroxyflavone (7,8,3-THF), a small-molecule TrkB agonist, on LTA-induced microglial activation. We report that 7,8,3-THF can significantly ameliorate interleukin (IL)-6 and NO production in LTA-stimulated BV2 cells. Taken together, our findings offer support for exploration of TLR2 as a potential target for therapeutic intervention into acute neuroinflammatory conditions. Moreover we propose that exposure to gram-positive bacterial pathogens may promote sensitivity to the inflammatory changes characteristic of the aged brain.

Bilobalide assuages morphine-induced addiction in hippocampal neuron cells through upregulation of microRNA-101

Bilobalide exhibits many biological activities, but its effects on morphine stimulation have not been elucidated. The research aims to explore the function and underlying mechanisms of bilobalide in morphine-led hippocampal neuron cells. Cells were treated with or without morphine or oxaliplatin (OXA), bilobalide, or SCH772984 dilutions. miR-101 inhibitor and negative control were transfected into cells. Western blot and quantitative reverse transcription-polymerase chain reaction were, respectively, conducted to measure the relative expression of proteins or RNAs. Morphine improved the expression levels of orexin1 receptor (OX1R) and c-FOS, the p/t-ERK/PKC as well. The c-FOS protein level and p/t-ERK/PKC were significantly elevated by morphine + OXA. Bilobalide had no effect on OX1R and p/t-PKC but evidently decreased the c-FOS and p/t-ERK. The p-ERK and the c-FOS accumulation levels were remarkably reduced by SCH772984. The production of miR-101 was promoted by bilobalide but inhibited by the miR-101 inhibitor. miR-101 inhibitor abolished bilobalide's inhibitory effects on p/t-ERK. Bilobalide exhibited morphine-induced effects on hippocampal neuron cells by upregulating miR-101.

Longxuetongluo capsule alleviates lipopolysaccharide-induced neuroinflammation by regulating multiple signaling pathways in BV2 microglia cells

BACKGROUND

Longxuetongluo capsule (LTC), derived from the total phenolic compounds of Chinese dragon's blood, is now used in the treatment of ischemic stroke in convalescence. The aim of this study is to explore the neuroprotective effect of LTC from the perspective of neuroinflammation.

METHODS

Cell viability and lactate dehydrogenase (LDH) release were measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and LDH assay kit. Proinflammatory mediators and cytokines production including Nitric Oxide (NO), prostaglandin E2, (PGE2), interleukin (IL-β), IL-6, and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) assay. In addition, western blot was used to detect the expression of inflammatory proteins associated with the mitogen-activated protein kinases (MAPKs), janus kinase/signal transducer and activator of tranions (JAK/STAT), nuclear transcription factor κB (NF-κB), and nuclear factor erythroid-2-related actor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathways. Moreover, immunofluorescence assay and electrophoretic mobility shift assays (EMSA) were performed to determine the Nrf2 translocation and the binding-DNA activity of NF-κB, respectively.

RESULTS

LTC at 0.5 to 2 μg/mL significantly increased cell viability and decreased LDH, NO, PGE2, IL-1β, IL-6, and TNF-α production in oxygen-glucose deprivation/reoxygenation (OGD/R) and lipopolysaccharide (LPS)-induced BV2 microglia cells. Meanwhile, LTC not only decreased the protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) but also down-regulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38, and up-regulated HO-1 expression via nuclear translocation of Nrf2. LTC can significantly inhibit the phosphorylation of JAK1/STAT3 and reduce the translocation of NF-κB from cytosol to nucleus as well as the binding-DNA activity. PC12 cell pretreated with LTC-condition medium (CM) significantly alleviated LPS-induced neurotoxicity and increased PC12 cell viability in a dose-dependent manner.

CONCLUSION

The present study showed that LTC exhibited a strong antineuroinflammatory activity and neuroprotective effects on LPS-stimulated BV2 microglial cells and PC12 cells.

Protective effects of organic extracts of Alpinia oxyphylla against hydrogen peroxide-induced cytotoxicity in PC12 cells

Alpinia oxyphylla, a traditional herb, is widely used for its neuroprotective, antioxidant and memory-improving effects. However, the neuroprotective mechanisms of action of its active ingredients are unclear. In this study, we investigated the neuroprotective effects of various organic extracts of Alpinia oxyphylla on PC12 cells exposed to hydrogen peroxide-induced oxidative injury in vitro. Alpinia oxyphylla was extracted three times with 95% ethanol (representing extracts 1–3). The third 95% ethanol extract was dried and resuspended in water, and then extracted successively with petroleum ether, ethyl acetate and n-butanol (representing extracts 4–6). The cell counting kit-8 assay and microscopy were used to evaluate cell viability and observe the morphology of PC12 cells. The protective effect of the three ethanol extracts (at tested concentrations of 50, 100 and 200 µg/mL) against cytotoxicity to PC12 cells increased in a concentration-dependent manner. The ethyl acetate, petroleum ether and n-butanol extracts (each tested at 100, 150 and 200 μg/mL) had neuroprotective effects as well. The optimum effective concentration ranged from 50–200 μg/mL, and the protective effect of the ethyl acetate extract was comparatively robust. These results demonstrate that organic extracts of Alpinia oxyphylla protect PC12 cells against apoptosis induced by hydrogen peroxide. Our findings should help identify the bioactive neuroprotective components in Alpinia oxyphylla.

Bilobalide protects H9c2 cell from oxygen-glucose-deprivation-caused damage through upregulation of miR-27a

Background: Myocardial ischemia is a troublesome disease. Bilobalide possesses multiple biological functions. We researched the consequents of bilobalide in OGD-irritated H9c2 cells. Methods: OGD-stimulated H9c2 cells were treated by bilobalide, and/or transfected with miR-27a inhibitor or negative control. Use CCK-8 and flow cytometry to test cell activity and apoptosis, respectively. Luciferase activity experiment was to test targeting link between miR-27a and Tmub1. Levels of cell-cycle and apoptosis relative proteins and phosphorylation of PI3K/AKT and Wnt/β-catenin related proteins were detected through western blot. Results: OGD stimulation reduced cell activity and negatively regulated the expression of CDK4, CDK6 and CyclinD1. Cell apoptosis was increased and its related proteins were affected by OGD. Bilobalide administration reversed all the results above caused by OGD. OGD negatively regulated miR-27a while bilobalide upregulated miR-27a. miR-27a's target gene was Tmub1. The protection consequents of bilobalide were suppressed when cells were transfected with a miR-27a inhibitor that cell activity was reduced and apoptosis was raised. Attenuation in the phosphorylation level of PI3K, AKT and β-catenin by OGD was reversed by bilobalide, whereas there were opposite results after transfected with miR-27a inhibitor. Conclusion: Bilobalide relieved OGD-caused H9c2 cell damage, raising cell activity and attenuating apoptosis via upregulating miR-27a and activating of PI3K/AKT and Wnt/β-catenin signal pathway. Highlights Bilobalide alleviates OGD-induced H9c2 cell injury. Bilobalide upregulates miR-27a expression in OGD-stimulated H9c2 cells. Bilobalide alleviates cell injury by upregulation of miR-27a. Bilobalide actuates PI3K/AKT and Wnt/β-catenin pathways.

Bilobalide Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

Bilobalide, the only sesquiterpene compound from Ginkgo biloba leaf, exhibits various beneficial pharmaceutical activities, such as antioxidant, anti-inflammation, and protective effects for the central nervous system. Several bioactive components extracted from Ginkgo biloba extract reportedly have the potential to attenuate lipid metabolism. However, the effect of bilobalide on lipid metabolism remains unclear. In this study, we used 3T3-L1 cells as the cell model to investigate the effect of bilobalide on adipogenesis. The results showed that bilobalide inhibited 3T3-L1 preadipocyte differentiation and intracellular lipid accumulation. Quantitative real-time PCR and western blotting results indicated that several specific adipogenic transcription factors and a few important adipogenesis-related genes were significantly down regulated on both mRNA and protein levels in bilobalide treatment groups. By contrast, the expression of some lipolytic genes, such as adipose triglyceride lipase, hormone-sensitive lipase (HSL), and carnitine palmitoyltransferase-1α, were all up-regulated by bilobalide treatment, and the phosphorylation of AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase 1, and HSL were stimulated. Furthermore, bilobalide treatment partially restored AMPK activity following its blockade by compound C (dorsomorphin). These results suggested that bilobalide inhibited adipogenesis and promoted lipolysis in 3T3-L1 cells by activating the AMPK signaling pathway.

Bilobalide protects astrocytes from oxygen and glucose deprivation-induced oxidative injury by upregulating manganese superoxide dismutase

Bilobalide (BB), a constituent of the Ginkgo biloba extract, is a neuroprotective agent with multiple mechanisms of action. To further explore the potential therapeutic effects of BB in stroke, we investigated its effects on primary astrocytes using the oxygen and glucose deprivation-reoxygenation (OGD-R) model. Cell viability was measured by lactate dehydrogenase release assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell death was measured by annexin 5 conjgated with fluorescein isothiocyanate (V-FITC) assay, and reactive oxygen species (ROS) production was measured by 2',7'-Dichlorodihydrofluorescein Diacetate (DCFH-DA) probe. Manganese superoxide dismutase (MnSOD) expression was measured by western blot and immunofluorescence. Mitochondrial membrane potential was monitored using JC-1 staining. Our results show that OGD-R downregulated MnSOD and impaired mitochondrial function, which further enhanced ROS production in primary astrocytes. As a result, cell viability was compromised, and cell death increased. BB treatment protected astrocytes from those injuries mainly by restoring MnSOD level as MnSOD inhibitor abolished the effects of BB. In conclusion, we demonstrated that OGD-R induced astrocytic injury, but BB increased the expression of MnSOD, the ROS scavenger, to reverse the exacerbated astrocytic injury.

Antioxidant effects of ginkgolides and bilobalide against cerebral ischemia injury by activating the Akt/Nrf2 pathway in vitro and in vivo

Ginkgolide terpenoid lactones, including ginkgolides and bilobalide, are two crucial bioactive constituents of extract of Ginkgo biloba (EGb) which was used in the treatment of cardiovascular and cerebrovascular diseases. The aims of this study were to investigate the antioxidant effects and mechanism of ginkgolides (ginkgolide A (GA), ginkgolide B (GB), ginkgolide K (GK)) and bilobalide (BB) against oxidative stress induced by transient focal cerebral ischemia. In vitro, SH-SY5Y cells were exposed to oxygen-glucose deprivation (OGD) for 4 h followed by reoxygenation with ginkgolides and BB treatments for 6 h, and then cell viability, superoxide dismutase (SOD), and ROS were respectively detected using kit. Western blot was used to confirm the protein levels of hemeoxygenase-1 (HO-1), quinone oxidoreductase l (Nqo1), Akt, phosphorylated Akt (p-Akt), nuclear factor-E2-related factor2 (Nrf2), and phosphorylated Nrf2 (p-Nrf2). GB combined with different concentrations of LY294002 (PI3K inhibitor) were administrated to SH-SY5Y cells for 1 h after OGD, and then p-Akt and p-Nrf2 levels were detected by western blot. In vivo, 2 h of middle cerebral artery occlusion (MCAO) model was established, followed with reperfusion and GB treatments for 24 and 72 h. The infarct volume ratios were confirmed by TTC staining. The protein levels of HO-1, Nqo1, SOD1, Akt, p-Akt, Nrf2, and p-Nrf2 were detected using western blot and immunohistochemistry (IHC). Experimental data in vitro confirm that GA, GB, GK, and BB resulted in significant decrease of ROS and increase of SOD activities and protein levels of HO-1 and Nqo1; however, GB group had a significant advantage in comparison with the GA and GK groups. Moreover, after ginkgolides and BB treatments, p-Akt and p-Nrf2 were significantly upregulated, which could be inhibited by LY294002 in a dose-dependent manner, meanwhile, GB exhibited more effective than GA and GK. In vivo, TTC staining indicated that the infarct volume ratios in MCAO rats were dramatically decreased by GB in a dose-dependent manner. Furthermore, GB significantly upregulated the protein levels of HO-1, Nqo1, SOD, p-Akt, p-Nrf2, and Nrf2. In conclusion, GA, GB, GK, and BB significantly inhibited oxidative stress damage caused by cerebral ischemia reperfusion. Compared with GA, GK, and BB, GB exerts the strongest antioxidant stress effects against ischemic stroke. Moreover, ginkgolides and BB upregulated the levels of antioxidant proteins through mediating the Akt/Nrf2 signaling pathway to protect neurons from oxidative stress injury.

Effects of hydrogen on polarization of macrophages and microglia in a stroke model

It has been confirmed that inflammation plays an important role in the pathogenesis of ischemic stroke. The polarization of microglia as an important participant in the inflammation following stroke is also found to be involved in stroke. This study aimed to investigate the effects of hydrogen gas on the polarization of macrophages/microglia in vitro. Raw264.7 cells were treated with lipopolysaccharides and then exposed to hydrogen. The microglia were treated with the supernatant from oxygen and glucose deprivation-treated neurons and then exposed to hydrogen. The phenotypes of Raw 264.7 cells and microglia were determined by flow cytometry, and cell morphology was observed. Results showed lipopolysaccharides significantly increased the M1 macrophages, and the supernatant from oxygen and glucose deprivation-treated neurons dramatically elevated the proportion of M1 microglia, but both treatments had little influence on the M2 cells. In addition, hydrogen treatment significantly inhibited the increase in M1 cells, but had no influence on M2 ones. Our findings suggest that the neuroprotection of hydrogen may be related to its regulation of microglia in the nervous system after stroke.

Neuroprotective Effect of Modified Xijiao Dihuang Decoction against Oxygen-Glucose Deprivation and Reoxygenation-Induced Injury in PC12 Cells: Involvement of TLR4-MyD88/NF-κB Signaling Pathway

Modified Xijiao Dihuang (XJDH) decoction has been shown to exert powerful neuroprotective properties in clinical ischemic stroke treatment. It consists of 4 Chinese herbs: Buffalo Horn, Paeonia suffruticosa Andrews, Rehmannia glutinosa (Gaertn.) DC, and Paeonia lactiflora Pall. In the present study, the neuroprotective effect and specific mechanisms of XJDH in protecting PC12 cells from oxygen-glucose deprivation-induced injury were investigated. It was found that OGD/R significantly decreased the cell viability and lactate dehydrogenase (LDH) activity and increased the release of IL-1β, IL-6, and TNF-α in PC12 cells, and these effects were suppressed by XJDH and one of its major active constituents, paeoniflorin. Additionally, XJDH inhibited caspase-3 activity and reduced cleaved caspase-3 level. Mechanistic studies showed that the expressions of TLR4, MyD88, TRAF6, and NF-κB p65 and phosphorylation of IκBα and p65 were significantly lower in the XJDH-treated group than in the OGD/R control group. Additionally, XJDH reversed the OGD/R-induced increases in p-JNK and p-ERK1/2 expression. These results suggest that XJDH protects PC12 cells from oxygen-glucose deprivation-induced injury, which may be associated with the inhibition of the TLR4-MyD88/NF-κB signaling pathway. As an anti-inflammation factor, XJDH might be used as a neuronal protection strategy for the ischemia injury and related diseases.

IL-17A Enhances Microglial Response to OGD by Regulating p53 and PI3K/Akt Pathways with Involvement of ROS/HMGB1

Cerebral ischemia-reperfusion injury (IRI) has a complex pathogenesis, and interleukin-17 (IL-17) is a newly identified class of the cytokine family that plays an important role in ischemic inflammation. An oxygen-glucose deprivation (OGD) model showed that IL-17A expression was significantly up-regulated in microglial cells. After IL-17A siRNA transfection, the inhibition of proliferation, and the increased apoptosis in microglial cells, induced by OGD/reperfusion, was improved, and the elevation of Caspase-3, Caspase-8, Caspase-9, and poly ADP ribose polymerase (PARP) activities was inhibited. Mass spectrometry demonstrated that IL-17A functioned through a series of factors associated with oxidative stress and apoptosis and regulated Caspase-3 activity and apoptosis in microglial cells via the p53 and PI3K/Akt signaling pathways. IL-17A, HMGB1, and ROS were regulated mutually to exhibit a synergistic effect in the OGD model of microglial cells, but the down-regulation of IL-17A or HMGB1 expression did not completely inhibit the production of ROS. These findings demonstrated that ROS might be located upstream of IL-17A and HMGB1 so that ROS can regulate HMGB1/IL-17A expression to affect the p53 and PI3K/Akt signaling pathways and therefore promote the occurrence of apoptosis in microglial cells. These findings provide a novel evidence for the role of IL-17A in ischemic cerebral diseases.

Interleukin-10 release from astrocytes suppresses neuronal apoptosis via the TLR2/NFκB pathway in a neonatal rat model of hypoxic-ischemic brain damage

The biological function of interleukin-10 (IL-10) and the relationship between IL-10 secretion and the Toll-like receptor 2 (TLR2) expression levels in the central nervous system following hypoxic-ischemic brain damage (HIBD) are poorly understood. Here, we intend to elucidate the biological function and mechanism of IL-10 secretion following HIBD. In this study, we used a neonatal rat model of HIBD and found that rats injected with adeno-associated virus-IL-10-shRNA (short hairpin RNA) exhibited partially impaired learning and memory function compared to rats administered adeno-associated virus-control-shRNA. In vitro oxygen-glucose deprivation (OGD) induced IL-10 release from astrocytes but not from neurons. Pretreatment with exogenous recombinant IL-10 alleviated OGD-mediated apoptosis of neurons but not astrocytes. In addition, we also observed that hypoxic injury induced a marked increase in IL-10 expression in astrocytes as a result of activation of the TLR2/phosphorylated nuclear factor kappa B (p-NFκB) p65 signaling cascade; furthermore, this effect disappeared upon small interfering RNA targeting rat TLR2 gene (siTLR2) treatment. Pyrrolidinedithiocarbamate, an inhibitor of NFκB activation, reduced the IL-10 expression levels in both OGD-injured astrocytes in vitro and the hippocampi of HIBD rats in vivo but did not significantly affect TLR2 expression. Furthermore, a luciferase assay revealed that p-NFκB p65 could bind the -1700/-1000 bp proximal region of the IL-10 gene promoter to regulate IL-10 secretion from astrocytes and that this interaction could be controlled by OGD treatment. These data suggest that HIBD induces IL-10 secretion from astrocytes to exert a paracrine-induced anti-apoptotic effect on injured neurons via the TLR2/NFκB signaling pathway, which may improve learning and memory dysfunction after ischemic injury.