Gypenoside IX Suppresses p38 MAPK/Akt/NFκB Signaling Pathway Activation and Inflammatory Responses in Astrocytes Stimulated by Proinflammatory Mediators

Gypenoside LXXV Alleviates Colitis by Reprograming Macrophage Polarization via the Glucocorticoid Receptor Pathway

An imbalance in the macrophage phenotype is closely related to various inflammatory diseases. Here, we discovered that gypenoside LXXV (GP-75), a type of saponin from Gynostemma pentaphyllum, can reprogram M1-like macrophages into M2-like ones. On a mechanistic level, GP-75 inhibits NF-κB-COX2 signaling by targeting the glucocorticoid receptor (GR). Administration of GP-75, either orally or by intraperitoneal injection, significantly alleviates ulcerative colitis in mice, a pathogenesis associated with macrophage polarization. Clodronate liposomes, which deplete macrophages in mice, as well as GR antagonist RU486, abrogate the anticolitis effect of GP-75, thus confirming the pivotal role of macrophages in GP-75 function. We also showed that GP-75 has no toxicity in mice. Overall, this is the first report that demonstrates the effect of GP-75 on macrophage reprograming and as an agent against colitis. Because G. pentaphyllum is gaining popularity as a functional food, our findings offer new perspectives on the use of gypenosides as potential nutraceuticals for medical purposes.

Neuroprotective effects of Gypenosides: A review on preclinical studies in neuropsychiatric disorders

Gynostemma pentaphyllum (Thunb.) Makino is a perennial creeping herb belonging to the Cucurbitaceae family that has a long history of usage in traditional oriental medicine. Gypenosides are the primary bioactive compounds in Gynostemma pentaphyllum. Because of the medicinal value of gypenosides, functional food and supplements containing gypenosides have been promoted and consumed with popularity, especially among Asian communities. This review presented the progress made in the research of pharmacological properties of gypenosides on diseases of the nervous system and their possible mechanism of action. To date, preclinical studies have demonstrated the therapeutic effects of gypenosides in alleviating neuropsychiatric disorders like depression, Parkinson's disease, Alzheimer's disease, secondary dementia, stroke, optic neuritis, etc. Pharmacological studies have discovered that gypenosides can modulate various major signaling pathways like NF-κB, Nrf2, AKT, ERK1/2, contributing to the neuroprotective properties. However, there is a dearth of clinical research on gypenosides, with current investigations on the compounds being mainly conducted in vitro and on animals. Future studies focusing on isolating and purifying novel gypenosides and investigations on exploring the potential molecular mechanism underlying their biological activities are warranted, which may serve as a foundation for further clinical trials for the betterment of human health.

Obstructive sleep apnea affects cognition: dual effects of intermittent hypoxia on neurons

Obstructive sleep apnea (OSA) is a common respiratory disorder. Multiple organs, especially the central nervous system (CNS), are damaged, and dysfunctional when intermittent hypoxia (IH) occurs during sleep for a long time. The quality of life of individuals with OSA is significantly impacted by cognitive decline, which also escalates the financial strain on their families. Consequently, the development of novel therapies becomes imperative. IH induces oxidative stress, endoplasmic reticulum stress, iron deposition, and neuroinflammation in neurons. Synaptic dysfunction, reactive gliosis, apoptosis, neuroinflammation, and inhibition of neurogenesis can lead to learning and long-term memory impairment. In addition to nerve injury, the role of IH in neuroprotection was also explored. While causing neuron damage, IH activates the neuronal self-repairing mechanism by regulating antioxidant capacity and preventing toxic protein deposition. By stimulating the proliferation and differentiation of neural stem cells (NSCs), IH has the potential to enhance the ratio of neonatal neurons and counteract the decline in neuron numbers. This review emphasizes the perspectives and opportunities for the neuroprotective effects of IH and informs novel insights and therapeutic strategies in OSA.

Huangqi-Guizhi-Wuwu decoction regulates differentiation of CD4+ T cell and prevents against experimental autoimmune encephalomyelitis progression in mice

BACKGROUND

Multiple sclerosis (MS) is a demyelination disorder caused by an overactive immune response. Its pathological characteristics include CNS inflammation, white matter demyelination, glial cell proliferation, and so on. Huangqi-Guizhi-Wuwu Decoction (HGWD), which is recorded in the Synopsis of the Golden Chamber, is used clinically for the therapy of MS, but its mechanism is still elusive.

PURPOSE

This study was aimed to investigate the impact of HGWD on the classical animal model for MS, experimental autoimmune encephalomyelitis (EAE), and explore the underlying action mechanism.

RESULTS

HGWD ameliorated the pathogenesis of EAE mice, and improved their neurobehavior and pathological tissue damage. Network pharmacology predictions revealed the action mechanism of HGWD in EAE mice might be related to its effect on the immune system of mice. HGWD effectively suppressed the inflammatory infiltration in CNS, while also preventing the elevation of CD4+T cells of mice with EAE. HGWD could increase the ratio of Treg cells, up-regulate the secretion of IL-10 and Foxp3 mRNA expression, inhibit the ratio of Th1 and Th17 cells, down-regulate the IFN-γ and IL-17 protein expression, as well as the RORγT and T-bet gene expression in EAE mice. In addition, HGWD-containing serum modulated Th1/Th17/Treg cell differentiation in vitro. Moreover, HGWD inhibited the p-JAK1, p-JAK2, p-STAT1, p-STAT3 and p-STAT4 proteins and elevated the p-STAT5 protein in lymphoid tissues of EAE mice.

CONCLUSION

HGWD improved the progress of EAE by regulating the proportion of CD4+T cell subtype differentiation, which might be exerted through JAK/STAT signaling pathway, providing a pharmacological basis for the clinical treatment of MS.

Gypenoside Pretreatment Alleviates the Cerebral Ischemia Injury via Inhibiting the Microglia-Mediated Neuroinflammation

Neuroinflammation is closely related to prognosis in ischemic stroke. Microglia are the main immune cells in the nervous system. Under physiological conditions, microglia participate in clearance of dead cells, synapse pruning and regulation of neuronal circuits to maintain the overall health of the nervous system. Once ischemic stroke occurs, microglia function in the occurrence and progression of neuroinflammation. Therefore, the regulation of microglia-mediated neuroinflammation is a potential therapeutic strategy for ischemic stroke. The anti-inflammatory activity of gypenosides (GPs) has been confirmed to be related to the activity of microglia in other neurological diseases. However, the role of GPs in neuroinflammation after ischemic stroke has not been studied. In this study, we investigated whether GPs could reduce neuroinflammation by regulating microglia and the underlying mechanism through qRT-PCR and western blot. Results showed that GPs pretreatment mitigated blood-brain barrier (BBB) damage in the mice subjected to middle cerebral artery occlusion (MCAO) and improved motor function. According to the results of immunofluorescence staining, GPs pretreatment alleviated neuroinflammation in MCAO mice by reducing the number of microglia and promoting their phenotypic transformation from M1 to M2. Furthermore, GPs pretreatment reduced the number of astrocytes in the penumbra and inhibited their polarization into the A1 type. We applied oxygen and glucose deprivation (OGD) on BV2 cells to mimic ischemic conditions in vitro and found similar effect as that in vivo. At the molecular level, the STAT-3/HIF1-α and TLR-4/NF-κB/HIF1-α pathways were involved in the anti-inflammatory effects of GPs in vitro and in vivo. Overall, this research indicates that GPs are potential therapeutic agents for ischemic stroke and has important reference significance to further explore the possibility of GPs application in ischemic stroke.

Essential Oil of Matricaria chamomilla Alleviate Psoriatic-Like Skin Inflammation by Inhibiting PI3K/Akt/mTOR and p38MAPK Signaling Pathway

Background

The traditional Matricaria chamomilla L. has been used to treat dermatitis for thousands of years. Due to emerging trends in alternative medicine, patients prefer natural remedies to relieve their symptoms. Therefore, finding safe and effective plant medicines for topical applications on the skin is an important treatment strategy for dermatologists. German chamomile (Matricaria chamomilla L.) from the Compositae family is a famous medicinal plant, often known as the "star of medicinal species."However, the function of Matricaria chamomilla essential oil on skin inflammation has not been thoroughly examined in earlier research.

Methods

GC-MS analyzed the components of MCEO, and this study explored the anti-inflammation effects of MCEO on psoriasis with network pharmacological pathway prediction. Following this, we used clinical samples of psoriasis patients to confirm the secretory characteristic of relative inflammatory markers. The therapeutic effect of MCEO on skin inflammation was detected by examination of human keratinocytes HaCaT. At the same time, we prepared imiquimod-induced psoriatic-like skin inflammation in mice to investigate thoroughly the potential inhibition functions of MCEO on psoriatic skin injury and inflammation.

Results

MCEO significantly reduced interleukin-22/tumor necrosis factor α/lipopolysaccharide-stimulated elevation of HaCaT cell inflammation, which was correlated with downregulating PI3K/Akt/mTOR and p38MAPK pathways activation mediated by MCEO in HaCaT cells treated with IL-22/TNF-α/LPS. Skin inflammation was evaluated based on the PASI score, HE staining, and relative inflammatory cytokine levels. The results showed that MCEO could significantly contribute to inflammatory skin disease treatment.

Conclusion

MCEO inhibited inflammation in HaCaT keratinocytes induced by IL-22/TNF-α/LPS, the potential mechanisms associated with inhibiting excessive activation and crosstalk between PI3K/Akt/mTOR and p38MAPK pathways. MCEO ameliorated skin injury in IMQ-induced psoriatic-like skin inflammation of mice by downregulating the levels of inflammatory cytokines but not IL-17A. Thus, anti-inflammatory plant drugs with different targets with combined applications were a potential therapeutic strategy in psoriasis.

Total Saponins of Panax Notoginseng Modulate the Astrocyte Inflammatory Signaling Pathway and Attenuate Inflammatory Injury Induced by Oxygen- Glucose Deprivation/Reperfusion Injury in Rat Brain Microvascular Endothelial Cells

OBJECTIVE

Reperfusion after cerebral ischemia causes brain injury. Total saponins of Panax notoginseng (PNS) have potential roles in protecting against cerebral ischemia-reperfusion injury. However, whether PNS regulates astrocytes on oxygen-glucose deprivation/reperfusion (OGD/R) injury in rat brain microvascular endothelial cells (BMECs) and its mechanism still need further clarification.

METHODS

Rat C6 glial cells were treated with PNS at different doses. Cell models were established by exposing C6 glial cells and BMECs to OGD/R. Cell viability was assessed, and levels of nitrite concentration, inflammatory factors (iNOS, IL-1β, IL-6, IL-8, TNF-α), and oxidative stress-related factors (MDA, SOD, GSH-Px, T-AOC) were subsequently measured through CCK8, Grice analysis, Western blot, and ELISA, respectively. The co-cultured C6 and endothelial cells were treated with PNS for 24 hours before model establishment. Then transendothelial electrical resistance (TEER), lactate dehydrogenase (LDH) activity, brain-derived neurotrophic factor (BDNF) content, and mRNA and protein levels and positive rates of tight junction proteins [Claudin-5, Occludin, ZO-1] were measured by a cell resistance meter, corresponding kits, ELISA, RT-qPCR, Western blot, and immunohistochemistry, respectively.

RESULTS

PNS had no cytotoxicity. PNS reduced iNOS, IL-1β, IL-6, IL-8, and TNF-α levels in astrocytes, promoted T-AOC level and SOD and GSH-Px activities, and inhibited MDA levels, thus inhibiting oxidative stress in astrocytes. In addition, PNS alleviated OGD/R injury, reduced Na-Flu permeability, and enhanced TEER, LDH activity, BDNF content, and levels of tight junction proteins Claudin-5, Occludin, ZO-1 in the culture system of astrocytes and rat BMECs after OGD/R.

CONCLUSION

PNS repressed astrocyte inflammation and attenuated OGD/R injury in rat BMECs.

Current and promising therapies based on the pathogenesis of Graves' ophthalmopathy

Graves' ophthalmopathy (GO) is a hyperthyroidism-related and immune-mediated disease that poses a significant threat to human health. The pathogenesis of GO primarily involves T cells, B cells, and fibroblasts, suggesting a pivotal role for the thyrotropin-antibody-immunocyte-fibroblast axis. Traditional treatment approaches for Graves' disease (GD) or GO encompass antithyroid drugs (ATDs), radioactive iodine, and beta-blockers. However, despite decades of treatment, there has been limited improvement in the global incidence of GO. In recent years, promising therapies, including immunotherapy, have emerged as leading contenders, demonstrating substantial benefits in clinical trials by inhibiting the activation of immune cells like Th1 and B cells. Furthermore, the impact of diet, gut microbiota, and metabolites on GO regulation has been recognized, suggesting the potential of non-pharmaceutical interventions. Moreover, as traditional Chinese medicine (TCM) components have been extensively explored and have shown effective results in treating autoimmune diseases, remarkable progress has been achieved in managing GO with TCM. In this review, we elucidate the pathogenesis of GO, summarize current and prospective therapies for GO, and delve into the mechanisms and prospects of TCM in its treatment.

Gypenoside-14 Reduces Depression via Downregulation of the Nuclear Factor Kappa B (NF-kB) Signaling Pathway on the Lipopolysaccharide (LPS)-Induced Depression Model

Neuroinflammation is a common pathogenetic sign of depression and is closely linked to the development of depression. Many clinical anti-inflammatory drugs act as antidepressants by reducing the neuroinflammatory response. Previous research found that gypenosides and their bioactive compound gypenoside-14 (GP-14) had neuroprotective effects against hypoxia-induced injury and reduced neuroinflammation-related high-altitude cerebral edema. Here we investigated the effects of GP-14 on the lipopolysaccharide (LPS)-induced depression-like behavior model. LPS (0.5 mg/kg) was injected into mice intraperitoneally for 7 consecutive days to induce depression-like behavior, which is considered a model for the exacerbation of depression. GP-14 in the amount of 100 mg/kg was simultaneously administered by gavage for 7 days. In the LPS-induced depression model, GP-14 not only attenuated depression-like behavior but also improved the anxiety-like behavior of the mice. Additionally, GP-14 treatment mitigated learning and cognitive decline in depressed mice. ELISA and immunofluorescence staining results revealed that GP-14 inhibited the upregulation of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and suppressed the activation of astrocytes induced with LPS, indicating its potent anti-inflammatory effect. GP-14 pretreatment in C8 cells and primary astrocytes can inhibit the activation of the NF-κB signaling pathway and downregulate the levels of pro-inflammatory factors. In summary, our findings showed that GP-14 had significant anti-inflammation and anti-depression properties; thus, GP-14 could be a promising lead compound for treating depression.

Taurochenodeoxycholic acid reduces astrocytic neuroinflammation and alleviates experimental autoimmune encephalomyelitis in mice

OBJECTIVE

Multiple sclerosis (MS) is an immune regulatory disease that affects the central nervous system (CNS). The main pathological features include demyelination and neurodegeneration, and the pathogenesis is associated with astrocytic neuroinflammation. Taurochenodeoxycholic acid (TCDCA) is one of the conjugated bile acids in animal bile, and it is not clear whether TCDCA could improve MS by inhibiting the activation of astrocytes. This study was aimed to evaluate the effects of TCDCA on experimental autoimmune encephalomyelitis (EAE)-a classical animal model of MS, and to probe its mechanism from the aspect of suppressing astrocytic neuroinflammation. It is expected to prompt the potential application of TCDCA for the treatment of MS.

RESULTS

TCDCA effectively alleviated the progression of EAE and improved the impaired neurobehavior in mice. It mitigated the hyperactivation of astrocytes and down-regulated the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in the brain cortex. In the C6 astrocytic cell line induced by lipopolysaccharide (LPS), TCDCA treatment dose-dependently decreased the production of NO and the protein expression of iNOS and glial fibrillary acidic protein (GFAP). TCDCA consistently inhibited the mRNA expressions of COX2, iNOS and other inflammatory mediators. Furthermore, TCDCA decreased the protein expression of phosphorylated serine/threonine kinase (AKT), inhibitor of NFκB α (IκBα) and nuclear factor κB (NFκB). And TCDCA also inhibited the nuclear translocation of NFκB. Conversely, as an inhibitor of the G-protein coupled bile acid receptor Gpbar1 (TGR5), triamterene eliminated the effects of TCDCA in LPS-stimulated C6 cells.

CONCLUSION

TCDCA improves the progress of EAE by inhibiting the astrocytic neuroinflammation, which might be exerted by the regulation of TGR5 mediated AKT/NFκB signaling pathway. These findings may prompt the potential application of TCDCA for MS therapy by suppressing astrocyte inflammation.

Discovery of New Heterocyclic/Benzofuran Hybrids as Potential Anti-Inflammatory Agents: Design, Synthesis, and Evaluation of the Inhibitory Activity of Their Related Inflammatory Factors Based on NF-κB and MAPK Signaling Pathways

NF-κB and MAPK are classic inflammation signaling pathways which regulate inflammation signal transmission and induce the expression of many inflammatory factors. Based on the potent anti-inflammatory activity of benzofuran and its derivatives, several new heterocyclic/benzofuran hybrids were first designed and synthesized by molecular hybridization. Their structure was confirmed by ¹H NMR, ¹³C NMR, HRMS or X-single crystal diffraction. The anti-inflammatory activity of these new compounds was screened by compounds; compound 5d exhibited an excellent inhibitory effect on the generation of NO (IC₅₀ = 52.23 ± 0.97 μM), and low cytotoxicity (IC₅₀ > 80 μM) against the RAW-264.7 cell lines. To further elucidate the possible anti-inflammatory mechanisms of compound 5d, the hallmark protein expressions of the NF-κB and MAPK pathways were studied in LPS-stimulated RAW264.7 cells. The results indicate that compound 5d not only significantly inhibits the phosphorylation levels of IKKα/IKKβ, IKβα, P65, ERK, JNK and P38 in the classic MAPK/NF-κB signaling pathway in a dose-dependent manner, but also down-regulates the secretion of pro-inflammatory factors such as NO, COX-2, TNF-α and IL-6. Further, the in vivo anti-inflammatory activity of compound 5d indicated that it could regulate the involvement of neutrophils, leukocytes and lymphocytes in inflammation processes, and reduce the expression of IL-1β, TNF-α and IL-6 in serum and tissues. These results strongly suggest that the piperazine/benzofuran hybrid 5d has a good potential for developing an anti-inflammatory lead compound, and the anti-inflammatory mechanism might be related to the NF-κB and MAPK signaling pathways.

An instant beverage rich in nutrients and secondary metabolites manufactured from stems and leaves of Panax notoginseng

Introduction

Radix Notoginseng, one of the most famous Chinese traditional medicines, is the dried root of Panax notoginseng (Araliaceae). Stems and leaves of P. notoginseng (SLPN) are rich in secondary metabolites and nutrients, and authorized as a food resource, however, its utilization needs further research.

Methods

A SLPN-instant beverage was manufactured from SLPN through optimization by response surface design with 21-fold of 48.50% ethanol for 39 h, and this extraction was repeated twice; the extraction solution was concentrated to 1/3 volume using a vacuum rotatory evaporator at 45°C, and then spray dried at 110°C. Nutritional components including 14 amino acids, ten mineral elements, 15 vitamins were detected in the SLPN-instant beverage; forty-three triterpenoid saponins, e.g., ginsenoside La, ginsenoside Rb3, notoginsenoside R1, and two flavonoid glycosides, as well as dencichine were identified by UPLC-MS.

Results

The extraction rate of SLPN-instant beverage was 37.89 ± 0.02%. The majority nutrients were Gly (2.10 ± 0.63 mg/g), His (1.23 ± 0.07 mg/g), α-VE (18.89 ± 1.87 μg/g), β-VE (17.53 ± 1.98 μg/g), potassium (49.26 ± 2.70 mg/g), calcium (6.73 ± 0.27 mg/g). The total saponin of the SLPN-instant beverage was 403.05 ± 34.98 mg/g, majority was notoginsenoside Fd and with contents of 227 ± 2.02 mg/g. In addition, catechin and γ-aminobutyric acid were detected with levels of 24.57 ± 0.21 mg/g and 7.50 ± 1.85 mg/g, respectively. The SLPN-instant beverage showed good antioxidant activities with half maximal inhibitory concentration (IC₅₀) for scavenging hydroxyl (OH^-) radicals, superoxide anion (O^2-) radicals, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS+) radicals were 0.1954, 0.2314, 0.4083, and 0.3874 mg/mL, respectively.

Conclusion

We optimized an analytical method for in depth analysis of the newly authorized food resource SLPN. Together, an instant beverage with antioxidant activity, rich in nutrients and secondary metabolites, was manufactured from SLPN, which may improve the utilization of SLPN.

APP Knock-In Mice Produce E22P-Aβ Exhibiting an Alzheimer's Disease-like Phenotype with Dysregulation of Hypoxia-Inducible Factor Expression

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that requires further pathological elucidation to establish effective treatment strategies. We previously showed that amyloid β (Aβ) toxic conformer with a turn at positions 22-23 is essential for forming highly toxic oligomers. In the present study, we evaluated phenotypic changes with aging in AD model AppNL-P-F/NL-P-F (NL-P-F) mice with Swedish mutation (NL), Iberian mutation (F), and mutation (P) overproducing E22P-Aβ, a mimic of toxic conformer utilizing the knock-in technique. Furthermore, the role of the toxic conformer in AD pathology was investigated. NL-P-F mice produced soluble toxic conformers from an early age. They showed impaired synaptic plasticity, glial cell activation, and cognitive decline, followed by the accumulation of Aβ plaques and tau hyperphosphorylation. In addition, the protein expression of hypoxia-inducible factor (HIF)-1α was increased, and gene expression of HIF-3α was decreased in NL-P-F mice. HIF dysregulation due to the production of soluble toxic conformers may be involved in AD pathology in NL-P-F mice. This study could reveal the role of a highly toxic Aβ on AD pathogenesis, thereby contributing to the development of a novel therapeutic strategy targeting the toxic conformer.

Therapeutic Effect of Gypenosides on Antioxidant Stress Injury in Orbital Fibroblasts of Graves’ Orbitopathy

Purpose

To examine the impact of gypenosides (Gyps) on oxidative stress damage of orbital fibroblasts (OFs) from Graves' ophthalmopathy (GO) patients.

Methods

The relationship between Gyps and GO oxidative stress was understood by bioinformatics analysis. Orbital connective tissues of GO and non-GO patients were obtained for primary OF culture. The proliferation level of OFs was measured by Cell Counting Kit-8 method, and the appropriate intervention concentration of Gyps and H₂O₂ was obtained. The expression of apoptosis-related protein mRNA was analyzed by RT-qPCR technique. ROS and SOD test suites were employed to detect the oxidative stress level in OFs. Flow cytometry apoptosis detection, TUNEL detection, and lactate dehydrogenase detection were used to analyze the level of apoptosis. Western blotting detection was utilized to examine the regulatory pathway of oxidative stress, apoptosis, and autophagy-related proteins. The changes of cell morphology, autophagosome, and autophagy lysosome were observed by transmission electron microscope.

Results

The suitable intervention concentration of Gyps is 100 μg/mL, and the suitable intervention concentration of high concentration H₂O₂ is 350 μM. In comparison with the blank control group, the H₂O₂ intervention group enhanced the expression of apoptosis-related mRNA, the expression of ROS and SOD, the apoptosis rate, the expression of autophagy activation-related protein and Nrf2/ERK/HO-1 protein, and the number of autophagosomes and autophagy lysosomes. Compared with H₂O₂ intervention group, the expression of apoptosis-related mRNA decreased, ROS expression decreased, SOD expression increased, apoptosis rate decreased, autophagy activation-related protein expression decreased, Nrf2/ERK/HO-1 protein expression increased, and the quantity of autophagosomes and autophagy lysosomes decreased in H₂O₂ + Gyps intervention group.

Conclusion

Gyps can decrease the oxidative stress level of OFs generated by H₂O₂, reduce cell autophagy, and reduce apoptosis. Gyps may regulate the oxidative stress response of OFs in GO patients via the Nrf2/ERK/HO-1 signaling pathway.

Curcumin Regulates Anti-Inflammatory Responses by AXL/JAK2/STAT3 Signaling Pathway in experimental autoimmune encephalomyelitis

Microglia-mediated neuroinflammation plays an important role in multiple sclerosis (MS). This study explored whether curcumin has a protective effect on experimental autoimmune encephalomyelitis (EAE), and the specific mechanism was investigated. We found that curcumin attenuates the severity of EAE mice. It inhibits the activation of microglia in the spinal cord of EAE mice and LPS-stimulated BV-2 cells. The findings clarify that curcumin may inhibit the inflammatory response mediated by microglia by inactivating the AXL/JAK2/STAT3 signaling pathway, which laid a theoretical foundation for the clinical management of MS.

Hyodeoxycholic acid inhibits lipopolysaccharide-induced microglia inflammatory responses through regulating TGR5/AKT/NF-κB signaling pathway

BACKGROUND

Hyodeoxycholic acid (HDCA) is a natural secondary bile acid with enormous pharmacological effects, such as modulating inflammation in neuron. However, whether HDCA could suppress microglial inflammation has not been elucidated yet.

AIMS

To determine the anti-microglial inflammatory effect of HDCA in lipopolysaccharide (LPS) models and its mechanisms.

METHODS

The effect of HDCA was evaluated in LPS-stimulated BV2 microglial cells in vitro and the cortex of LPS-treated mice in vivo. Immunohistochemistry and immunofluorescence were used to visualize the localization of nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) and ionized calcium-binding adaptor protein-1 (Iba-1), respectively. The mRNA expression of inflammatory cytokines was measured by RT-qPCR. The protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), takeda G-coupled protein receptor 5 (TGR5), and the phosphorylation of protein kinase B (AKT), NF-κB, and inhibitor of NF-κB protein α (IκBα) was examined by Western blot.

RESULTS

HDCA inhibited the inflammatory responses in LPS-treated BV2 cells and in the cortex of LPS-treated mice, evidenced by decreased production of inflammatory mediators such as iNOS, COX-2, tumor necrosis factor (TNF-α), interleukin (IL)-6, and IL-1β. Further study demonstrated that HDCA repressed the phosphorylation, nuclear translocation, and transcriptional activity of NF-κB and inhibited the activation of AKT in BV-2 cells induced by LPS. Meanwhile, addition of TGR5 inhibitor, triamterene, abolished the effects of HDCA on TGR5, AKT, and NF-κB.

CONCLUSION

The present study demonstrated that HDCA prevents LPS-induced microglial inflammation in vitro and in vivo, the action of which is via regulating TGR5/AKT/NF-κB signaling pathway.

New Therapeutic Horizon of Graves' Hyperthyroidism: Treatment Regimens Based on Immunology and Ingredients From Traditional Chinese Medicine

Graves’ disease is an autoimmune disease characterized by goiter and hyperthyroidism, and 25% patients develop GO. Traditional treatment options, such as antithyroid drugs, radioiodine or thyroidectomy, have remained largely unchanged over the past 70 years. For many patients, there is a high rate of recurrence after antithyroid drugs and lifelong hypothyroidism after ablation and thyroidectomy. The symptoms and quality of life of some patients have not been effectively improved. The clinical demand for new therapeutic regimens, coupled with a deeper understanding of the pathophysiology and immunobiology of Graves’ disease, has led to the emergence of several new therapeutic ideas, including biologics, small molecule peptides, immunomodulators and teprotumumab, a specific antibody targeting IGF-1R. Besides, the elements of TCM have attracted more and more interests in modern medicine, because some effective components have been successfully used in the treatment of autoimmune diseases. Based on the pathophysiology and efficacy of clinical management and treatment in Graves’ hyperthyroidism, here we review the new strategies under investigation and summarize the effective components of traditional Chinese medicine used for Graves’ hyperthyroidism, and explore their mechanisms. These therapies have opened a new window for the treatment of Graves’ disease, but the exact mechanism and the research direction still need to be further explored.

A bioactive gypenoside (GP-14) alleviates neuroinflammation and blood brain barrier (BBB) disruption by inhibiting the NF-κB signaling pathway in a mouse high-altitude cerebral edema (HACE) model

BACKGROUND

Neuroinflammation caused by peripheral lipopolysaccharides (LPS) under hypoxia is a key contributor to the development of high altitude cerebral edema (HACE). Our previous studies have shown that gypenosides and their bioactive compounds prevent hypoxia-induced neural injuries in vitro and in vivo. However, their effect on neuroinflammation-related HACE remains to be illustrated. The present study aimed to investigate the effects of GP-14 in HACE mouse model.

METHODS

HACE mice were treated with GP-14 (100 and 200 mg/kg) for 7 days. After the treatments, the level of serum inflammation cytokines and the transcription of inflammatory factors in brain tissue were determined. The activation of microglia, astrocyte and the changes of IgG leakage and the protein levels of tight junction proteins were detected. Furthermore, the inflammatory factors and nuclear factor-κB (NF-κB) signaling pathway in BV-2 cells and primary microglia were detected.

RESULTS

GP-14 pretreatment alleviated both the serum and neural inflammatory responses caused by LPS stimulation combined with hypobaric hypoxia exposure. In addition, GP-14 pretreatment inhibited microglial activation, accompanied by a decrease in the M1 phenotype and an increase in the M2 phenotype. Moreover, the disruption of the blood brain barrier (BBB) integrity, including increased IgG leakage and decreased expression of tight junction proteins, was attenuated by GP-14 pretreatment. Based on the BV-2 and primary microglial models, the inflammatory response and activation of the NF-κB signaling pathway were also inhibited by GP-14 pretreatment.

CONCLUSION

Taken together, our results demonstrated that GP-14 exhibited prominent protective roles against neuroinflammation and BBB disruption in a mouse HACE model. GP-14 could be a potential choice for the treatment of HACE in the future.

Network pharmacology analysis reveals neuroprotection of Gynostemma pentaphyllum (Thunb.) Makino in Alzheimer' disease

Background

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders in the world, but still lack of effective drug treatment. Gynostemma Pentaphyllum (Thunb.) Makino (GpM), a Chinese medicinal herb, plays important roles in anti-inflammation, anti-oxidative stress and anti-tumor, which has been reported to ameliorate cognitive impairment of AD. However, the neuroprotective mechanism of GpM remains unclear. This study aims to investigate the targets and possible signaling pathways of GpM in the treatment of AD.

Methods

Active compounds of GpM and their putative target proteins were selected from Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform. AD-associated targets were identified from GeneCards, the Online Mendelian Inheritance in Man (OMIM) database and the Therapeutic Target Database (TTD). The intersecting targets of GpM and AD were identified and Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out to analyze the mechanism of them. Compound-target-pathway (CTP) network and protein–protein interaction (PPI) network were constructed and analyzed to elucidate the correlation between compounds, proteins and pathways. Molecular docking was performed to further demonstrate the possibility of GpM for AD.

Results

A total of 13 active compounds of GpM, 168 putative target proteins of compounds and 722 AD-associated targets were identified. Eighteen intersecting targets of GpM and AD were found and the epidermal growth factor receptor (EGFR), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), nitric oxide synthase in endothelial (NOS3) and serum paraoxonase/arylesterase 1 (PON1) were selected as the primary targets of GpM in the treatment of AD. The neuroprotective effect of GPM was related to a variety of pathways, including amoebiasis, HIF-1 signaling pathway, cytokine-cytokine receptor interaction and so on.

Conclusions

Our findings elucidate the active compounds, targets and pathways of GpM involved in effects of anti-AD. The novel mechanism of GpM against AD provides more treatment options for AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03534-z.

Dammarane-type saponins from Gynostemma pentaphyllum and their cytotoxicities

Heat-processed Gynostemma pentaphyllum has shown strong activity against human lung carcinoma A549 cells. In this study, two dammarane-type saponins together with two known compounds were isolated from the ethanol extract of the heat-processed leaves of G. pentaphyllum. They were identified as 2α,3β,12β-trihydroxydammar-20(22),24-diene-3-O-β-D-glucopyranoside (1, namely damulin E), 2α,3β,12β-trihydroxydammar-20,24-diene-3-O-β-D-glucopyranoside (2, namely damulin F), damulin A (3) and damulin B (4), respectively, using NMR and mass spectra. Damulin E and damulin F showed moderate activity against A549, H1299, T24, SH-SY5Y and K562 cell lines in vitro using CCK-8 assay.

New dammarane-type triterpenoid saponins from Gynostemma pentaphyllum and their Sirt1 agonist activity

Gynostemma pentaphyllum (Thunb.) Makino (Cucurbitaceae family) is a perennial creeping plant with a common Chinese name of "south ginseng". To date, more than 250 individual saponins with dammarane-type skeleton have been isolated from G. pentaphyllum. The purpose of this study was the isolation and structural characterization of novel, minor gypenosides from G. pentaphyllum and evaluation of their Sirt1 agonist activity. Individual saponins from G. pentaphyllum were isolated and purified by a variety of chromatography techniques, and their structures were elucidated by means of various spectroscopic analysis and comparision with the reported data. Sirt1 enzyme activity detection kit was used to preliminarily evaluate the Sirt1 agonist activity of thirty three individual saponins purified from G. pentaphyllum. Fourteen new triterpenoid saponins named gypenoside CII-CXV (1-14) along with twenty six known compounds (15-40) were isolated from G. pentaphyllum. Thirty three of all the isolates were screened for Sirt1 agonist activity, and the results showed that three dammarane-type saponins (2, 18, 37) and one cucurbitane-type saponin 33 exhibited satisfactory Sirt1 agonist activity. These findings suggested that G. pentaphyllum was worthy of further investigation to find small molecule Sirt1 agonist and facilitate their utilization as "south ginseng".

(-)-Syringaresinol suppressed LPS-induced microglia activation via downregulation of NF-κB p65 signaling and interaction with ERβ

Albiziae Cortex (AC) is a well-known traditional Chinese medicine with sedative-hypnotic effects and neuroprotective ability. However, the bioactive components of AC responsible for the neuro-protective actitivity remain unknown. Here, we investigated the anti-neuroinflammatory effects of (-)-syringaresinol (SYR) extracted from AC in microglia cells and wild-type mice. As a result, (-)-SYR significantly reduced lipopolysaccharide (LPS)-induced production of interleukin - 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin -1 beta (IL-1β), cycloxygenase-2 (COX-2), and nitric oxide (NO) in BV2 microglia cells. (-)-SYR also significantly reduced M1 marker CD40 expression and increased M2 marker CD206 expression. Moreover, we found that (-)-SYR inhibited LPS-induced NF-κB activation by suppressing the translocation of NF-κB p65 into the nucleus in a concentration-dependent manner. Meanwhile, estrogen receptor β (ERβ) was found to be implied in the anti-inflammatory activity of (-)-SYR in BV2 microglia. In vivo experiments revealed that administration of (-)-SYR in mice significantly reduced microglia/astrocytes activation and mRNA levels of proinflammatory mediators. Taken together, our data indicated that (-)-SYR exerted the anti-neuroinflammatory effects by inhibiting NF-κB activation and modulation of microglia polarization, and via interaction with ERβ. The anti-neuroinflammatory activity of (-)-SYR may provide a new therapeutic avenue for the treatment of brain diseases associated with inflammation.

Evaluation of Anti-inflammatory Nutraceuticals in LPS-induced Mouse Neuroinflammation Model: An Update

It is known that peripheral infections, accompanied by inflammation, represent significant risk factors for the development of neurological disorders by modifying brain development or affecting normal brain aging. The acute effects of systemic inflammation on progressive and persistent brain damage and cognitive impairment are well documented. Anti-inflammatory therapies may have beneficial effects on the brain, and the protective properties of a wide range of synthetic and natural compounds have been extensively explored in recent years. In our previous review, we provided an extensive analysis of one of the most important and widely-used animal models of peripherally induced neuroinflammation and neurodegeneration - lipopolysaccharide (LPS)-treated mice. We addressed the data reproducibility in published research and summarized basic features and data on the therapeutic potential of various natural products, nutraceuticals, with known anti-inflammatory effects, for reducing neuroinflammation in this model. Here, recent data on the suitability of the LPS-induced murine neuroinflammation model for preclinical assessment of a large number of nutraceuticals belonging to different groups of natural products such as flavonoids, terpenes, non-flavonoid polyphenols, glycosides, heterocyclic compounds, organic acids, organosulfur compounds and xanthophylls, are summarized. Also, the proposed mechanisms of action of these molecules are discussed.

Gypenosides Inhibit Inflammatory Response and Apoptosis of Endothelial and Epithelial Cells in LPS-Induced ALI: A Study Based on Bioinformatic Analysis and in vivo/vitro Experiments

Introduction

Severe inflammatory response leads to poor prognosis of acute lung injury (ALI), the role of gypenosides (GPs) on ALI is not fully clear. The study aimed at investigating the effects of GPs on ALI.

Methods

We firstly established LPS-induced ALI mice model. Then, we tested whether GPs contributed to alleviate inflammatory response and lung injury of ALI in vivo. In order to identify specific mechanisms of the phenomenon, we conducted a bioinformatic analysis of LPS-induced ALI mice based on GEO database to identify hub differentially expressed genes (DEGs). PPI network of the DEGs was used to find hub-genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted based on the DAVID database to identify which pathways the genes enriched. Then, we tested whether GPs inhibited lung injury and inflammatory response via the enriched pathways. We also tested whether GPs inhibited the apoptosis of endothelial and epithelial cells secondary to severe inflammation.

Results

We found GPs significantly alleviated lung injury and improved the survival rate of LPS-induced ALI mice in vivo. Bioinformatic analysis identified 20 hub-genes from DEGs, they were mainly enriched in NF-κB and TNF-α pathways. GPs could reduce the lung injury and inflammatory response via inhibiting NF-κB and TNF-α pathways in vivo. Our results indicated that GPs also inhibited inflammatory response of epithelial and endothelial cells via NF-κB and TNF-α pathways in vitro. Severe inflammatory response could also lead to apoptosis of endothelial and epithelial cells. Our results indicated that GPs effectively inhibited the apoptosis of endothelial and epithelial cells.

Conclusion

Our study suggested GPs contributed to alleviated lung injury in vivo and inhibited inflammation and apoptosis of endothelial and epithelial cells in vitro, providing novel strategies for the prevention and therapy for ALI.

Panaxytriol Inhibits Lipopolysaccharide-Induced Microglia Activation in Brain Inflammation in Vivo

Brain inflammation is a pathological characteristic of neurodegenerative diseases. In this condition, excessively activated microglia elevate proinflammatory mediator levels. We previously reported that panaxytriol inhibited lipopolysaccharide (LPS)-induced microglia activation in vitro. However, the effects of panaxytriol on microglia activation in vivo require confirmation. In the present study, we found that panaxytriol suppressed both microglia and astrocyte activation by injected LPS intracerebrally to mice with LPS-induced brain inflammation. Panaxytriol was more effective on microglia than astrocytes. Moreover, panaxytriol tended to reduce LPS-induced spontaneous motor activity dysfunction. These results suggested that panaxytriol could improve brain health by suppressing microglia activation in neurodegenerative diseases.

Total flavonoids of astragalus attenuates experimental autoimmune encephalomyelitis by suppressing the activation and inflammatory responses of microglia via JNK/AKT/NFκB signaling pathway

BACKGROUND

Microglia-mediated neuroinflammation is one of the most prominent characteristics of multiple sclerosis (MS), a chronic demyelination disease. As one of the main active ingredients in Astragali radix, total flavonoids of Astragalus (TFA) has multiple pharmacological effects such as immunomodulation, anti-inflammation and and anti-tumor. However, little is known about whether TFA could inhibit microglia-mediated neuroinflammation in MS.

PURPOSE

This study was aimed to elucidate whether TFA could inhibit microglia-mediated neuroinflammation in MS.

STUDY DESIGN

In the present study, we explored the protective effect of TFA on experimental autoimmune encephalomyelitis (EAE), an animal model of MS, in mice for the first time, and discussed its mechanism from the aspect of anti-microglia-mediated neuroinflammation.

METHODS

The mice received oral administration of TFA (25 and 50 mg/kg) daily from two days before immunization and continued until day 21 post-immunization. The effect of TFA on EAE in mice and its mechanism were investigated by ELISA, Western blot, real-time PCR, luciferase reporter assay, histopathology and immunohistochemistry.

RESULTS

TFA were shown to alleviate the severity of EAE in mice. It inhibited the excessive activation of microglia both in spinal cords of EAE mice and in LPS-stimulated BV-2 cells, evidenced by weakening the production of inflammatory mediators such as NO, TNF-α, IL-6, and IL-1β markedly at either protein or mRNA level. Further study demonstrated that TFA repressed the phosphorylation, nuclear translocation and transcriptional activity of NFκB, and inhibited the activation of AKT and JNK signaling in BV-2 cells induced by LPS. The agonists of AKT and JNK, anisomycin and SC79, could partly abolish the inhibitory effect of TFA on the production of inflammatory mediators in BV-2 cells induced by LPS.

CONCLUSIONS

Taken together, our results clarified that TFA inhibited microglia-mediated inflammation in EAE mice probably through deactivating JNK/AKT/NFκB signaling pathways. The novel findings may lay a theoretical foundation for the clinical application of TFA in the treatment of MS.

Urolithin A Prevents Focal Cerebral Ischemic Injury via Attenuating Apoptosis and Neuroinflammation in Mice

Neuroinflammation contributes to neuronal death in cerebral ischemia. Urolithin A (UA), a gut microbial metabolite of ellagic acid, has emerged as a potential anti-inflammatory agent. However, its roles and precise mechanisms in stroke remain unknown. Here we found that UA treatment ameliorated infarction, neurological deficit scores, and spatial memory deficits after cerebral ischemia. Furthermore, UA significantly reduced neuron loss and promoted neurogenesis after ischemic stroke. We also found that UA attenuated apoptosis by regulating apoptotic-related proteins. Meanwhile, UA treatment inhibited glial activation via affecting inflammatory signaling pathways, specifically by enhancing cerebral AMPK and IκBa activation while decreasing the activation of Akt, P65NFκB, ERK, JNK, and P38MAPK. Our findings reveal a key role of UA against ischemic stroke through modulating apoptosis and neuroinflammation in mice.

Cinnamaldehyde Inhibits Inflammation of Human Synoviocyte Cells Through Regulation of Jak/Stat Pathway and Ameliorates Collagen-Induced Arthritis in Rats

Cinnamaldehyde (Cin), a bioactive cinnamon essential oil from traditional Chinese medicine herb Cinnamomum cassia, has been reported to have multipharmacological activities including anti-inflammation. However, its role and molecular mechanism of anti-inflammatory activity in musculoskeletal tissues remains unclear. Here, we first investigated the effects and molecular mechanisms of Cin in human synoviocyte cells. Then in vivo therapeutic effect of Cin on collagen-induced arthritis (CIA) also studied. Cell Counting Kit ‎CCK-8 assay was performed to evaluate the cell cytotoxicity. Proinflammatory cytokine expression was evaluated using quantitative polymerase chain reaction and ELISA. Protein expression was measured by western blotting. The in vivo effect of Cin (75 mg/kg per day) was evaluated in rats with CIA by gavage administration. Disease progression was assessed by clinical scoring, radiographic, and histologic examinations. Cin significantly inhibited interleukin (IL)-1β-induced IL-6, IL-8, and tumor necrosis factor-α release from human synoviocyte cells. The molecular analysis revealed that Cin impaired IL-6-induced activation of Janus kinase 2 (JAK2), signal transducer and activator of transcription 1 (STAT1), and STAT3 signaling pathway by inhibiting the phosphorylation of JAK2, STAT1, and STAT3, without affecting NF-κB pathway. Cin reduced collagen-induced swollen paw volume of arthritic rats. The anti-inflammation effects of Cin were associated with decreased severity of arthritis, joint swelling, and reduced bone erosion and destruction. Furthermore, serum IL-6 level was decreased when Cin administered therapeutically to CIA rats. Cin suppresses IL-1β-induced inflammation in synoviocytes through the JAK/STAT pathway and alleviated collagen-induced arthritis in rats. These data indicated that Cin might be a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug. SIGNIFICANCE STATEMENT: In this study, we found that cinnamaldehyde (Cin) suppressed proinflammatory cytokines secretion in rheumatology arthritis synoviocyte cells by Janus kinase/signal transducer and activator of transcription pathway. The in vivo results showed that Cin ameliorated collagen-induced arthritis in rats. These findings indicate that Cin is a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug.

Anti‑inflammatory role of Prunus persica L. Batsch methanol extract on lipopolysaccharide‑stimulated glial cells

Glial cells are the resident immune cells of the central nervous system. Reactive glial cells release inflammatory mediators that induce neurotoxicity or aggravate neurodegeneration. Regulation of glial activation is crucial for the initiation and progression of neuropathological conditions. Constituents of the peach tree (Prunus persica L. Batsch), which has a global distribution, have been found to exert therapeutic effects in pathological conditions, such as rashes, eczema and allergies. However, the therapeutic potential of its aerial parts (leaves, fruits and twigs) remains to be elucidated. The present study aimed to evaluate the anti-inflammatory role of P. persica methanol extract (PPB) on lipopolysaccharide (LPS)-stimulated glial cells. High-performance liquid chromatography coupled with tandem mass spectrometry analysis showed that PPB contained chlorogenic acid and catechin, which have antioxidant properties. Western blot and reverse transcription polymerase chain reaction results indicated that PPB reduced the transcription of various proinflammatory enzymes (nitric oxide synthase and cyclooxygenase-2) and cytokines [tumor necrosis factor-α, interleukin (IL)-1β and IL-6] in LPS-stimulated BV2 cells. In addition, PPB inhibited the activation of NF-κB and various mitogen-activated protein kinases required for proinflammatory mediator transcription. Finally, nitrite measurement and immunocytochemistry results indicated that PPB also suppressed nitrite production and NF-κB translocation in LPS-stimulated primary astrocytes. Thus, PPB may be used as a potential therapeutic agent for neurodegenerative diseases and neurotoxicity via the suppression of glial cell activation.

Ginkgo diterpene lactones inhibit cerebral ischemia/reperfusion induced inflammatory response in astrocytes via TLR4/NF-κB pathway in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. (Ginkgoaceae) is a traditional Chinese medicine known to treating stroke and other cardio-cerebrovascular diseases for thousands of years in China. Ginkgo diterpene lactones (GDL) attracted much attention because of their neuroprotective properties.

AIM OF THE STUDY

To uncover the effects of GDL, which consist of ginkgolide A (GA), ginkgolide B (GB), and ginkgolide K (GK), on ischemic stroke, as well as the underlying molecular mechanisms.

MATERIALS AND METHODS

We used middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) models mimicking the process of ischemia/reperfusion in vivo and in vitro, respectively. Anticoagulant effects of GDL were investigated on platelet activating factor (PAF), arachidonic acid (AA) and adenosine diphosphate (ADP)-induced platelet aggregation both in vivo and in vitro. We also evaluated the effects of GDL on lipopolysaccharide (LPS)-induced inflammatory response in primary cultured rats' astrocytes. Infarct size, neurological deficit score, and brain edema were measured at 72 h after MCAO. Immunohistochemistry was utilized to analyze neurons necrosis and astrocytes activation. Expression of pro-inflammatory cytokines, including tumor necrotic factor-α (TNF-α) and interleukin-1β (IL-1β) were detected using enzyme-linked immunosorbent assay (ELISA) and real time PCR. The levels of toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) were assessed by real time PCR or Western blot.

RESULTS

Compared with MCAO/R rats, GDL significantly reduced infarct size and brain edema, improved neurological deficit score. Meanwhile, GDL suppressed platelet aggregation, astrocytes activation, pro-inflammatory cytokines releasing, TLR4 mRNA expression and transfer of NF-κB from cytoplasm to nucleus. Furthermore, GDL alleviated OGD/R injury and LPS-induced inflammatory response in primary astrocytes, characterized by promoting cell viability, decreasing lactate dehydrogenase (LDH) activity, and inhibiting IL-1β and TNF-α releasing.

CONCLUSIONS

In summary, GDL attenuate cerebral ischemic injury, inhibit platelet aggregation and astrocytes activation. The anti-inflammatory activity might be associated with the downregulation of TLR4/NF-κB signal pathway. Our present findings provide an innovative insight into the novel treatment of GDL in ischemic stroke therapy.

Early astragaloside IV administration attenuates experimental autoimmune encephalomyelitis in mice by suppressing the maturation and function of dendritic cells

AIMS

Dendritic cells (DCs) actively participate in the pathogenesis of multiple sclerosis (MS), an autoimmune disease. Astragaloside IV (ASI), an active monomer isolated from the Chinese medicine Astragalus membranaceus, has a wide range of pharmacological effects. We aimed to elucidate the effects of ASI on the development of DCs in the early stage of MS/EAE.

MAIN METHODS

The mice were administered with ASI (20 mg/kg) daily 3 days in advance of EAE induction and continuously until day 7 post-immunization. The effect of ASI on CD11c⁺ DC cells from bone marrow (BMDCs) or the spleen of EAE mice at day 7 post-immunization were investigated respectively by flow cytometry, ELISA, western blot, real-time PCR and immunofluorescence.

KEY FINDINGS

ASI administration in the early stage of EAE was demonstrated to delay the onset and alleviate the severity of the disease. ASI inhibited the maturation and the antigen presentation of DCs in spleen of EAE mice and LPS-stimulated BMDCs, as evidenced by decreased expressions of CD11c, CD86, CD40 and MHC II. Accordingly, DCs treated by ASI secreted less IL-6 and IL-12, and prevented the differentiation of CD4⁺ T cells into Th1 and Th17 cells, which was probably through inhibiting the activation of NFκB and MAPKs signaling pathways.

SIGNIFICANCE

Our results implicated the alleviative effect of early ASI administration on EAE might be mediated by suppressing the maturation and function of DCs. The novel findings may add to our knowledge of ASI in the potentially clinical treatment of MS.

Medicinal Value and Potential Therapeutic Mechanisms of Gynostemma pentaphyllum (Thunb.) Makino and Its Derivatives: An Overview

:

Gynostemma pentaphyllum (Thunb.) Makino (GpM) and its derivatives, especially gypenosides (Gyps), are widely used as safe and convenient natural herbal drugs for the treatment of many diseases for a long time, and Gyps have different oral bioavailability (OB) values and low ability to cross the blood-brain barrier (BBB). The effects of GpM and isolates on fibrosis, inflammation, oxidation, proliferation and migration are proved. GpM shows bidirectional regulation effect on proliferation, oxidation and apoptosis in tumor and non-tumor cells. GpM and its extractions can resist proliferation, activate oxidation and apoptosis in tumor cells and have opposite effects on non-tumor cells. We succinctly present some current views of medicinal value and potential therapeutic mechanisms of GpM and its derivatives.

Inhibition of HDAC6 alleviating lipopolysaccharide-induced p38MAPK phosphorylation and neuroinflammation in mice

Context: Researchers in a variety of fields have extensively focused on histone deacetylase 6 (HDAC6) due to its aggravation of inflammatory reaction. However, relevant studies examining whether HDAC6 could exacerbate lipopolysaccharide (LPS)-induced inflammation are still lacking. Objective: We assessed the role of HDAC6 in LPS-induced brain inflammation and used the HDAC6-selective inhibitor Tubastatin A (TBSA) to investigate the potential mechanisms further. Materials and methods: Brain inflammation was induced in Kunming (KM) mice via intraperitoneal (I.P.), injection of Lipopolysaccharide (LPS) (1 mg/kg), the TBSA (0.5 mg/kg) was delivered via intraperitoneal. The phosphorylated p38 (p-p38) Mitogen-activated protein kinases (MAPK) and expression of typical inflammatory mediators, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in both the hippocampus and cortex, were examined by immunoblotting. Nissl staining was used to detect the neuronal damage in the hippocampus and the cortex. Results: About 1 mg/kg LPS via daily intraperitoneal (I.P.) injections for 12 days significantly increased p38 MAPK phosphorylation, TNF-α and IL-6 expression, and neuronal loss. However, 0.5 mg/kg TBSA (three days before LPS treatment) by I.P. injections for 15 days could reverse the above results. Conclusions: This present study provided evidence that TBSA significantly suppressed LPS-induced neuroinflammation and the expression of p-p38. Results derived from our study might help reveal the effective targeting strategies of LPS-induced brain inflammation through inhibiting HDAC6.

Hydrogen-rich Saline Alleviated the Hyperpathia and Microglia Activation via Autophagy Mediated Inflammasome Inactivation in Neuropathic Pain Rats

Neuropathic pain is a complication after a spinal nerve injury. The inflammasomes are now identified to be responsible for triggering inflammation in neuropathic pain. Autophagy participates in the process of neuropathic pain and can regulate the inflammasome activation in different diseases. Our previous research reported that hydrogen exerted a protective effect against neuropathic pain. Therefore, we focused on the mechanism and role of autophagy and inflammasome, by which hydrogen alleviated the hyperpathia induced by neuropathic pain. The results showed that neuropathic pain stimulated activation of inflammasome NLRP3 and autophagy pathway in the microglial cells of the spinal cord. The inhibition of NLRP3 inhibited the hyperpathia induced by spinal nerve litigation surgery. The absence of autophagy aggravated the inflammasome activity and hyperpathia. Hydrogen promoted autophagy related protein expression, inhibited the inflammasome NLRP3 pathway activation, and relieved the hyperpathia induced by neuropathic pain. Hydrogen treatment could alleviate hyperpathia by autophagy-mediated NLRP3 inactivation.

Research on the Potential Mechanism of Gypenosides on Treating Thyroid-Associated Ophthalmopathy Based on Network Pharmacology

Thyroid-associated ophthalmopathy is the commonest orbital disease in adults. However, shortcomings still exist in treatments. The aim of this study was to identify the efficacy and potential mechanism of gypenosides in the treatment of thyroid-associated ophthalmopathy. The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform was screened for active compounds of gypenosides, and targets were predicted using Swiss Target Prediction. The targets of thyroid-associated ophthalmopathy were obtained from Online Mendelian Inheritance in Man, Comparative Toxicogenomic Database and GeneCards Human gene database. Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome Pathways were determined based on the common targets. Protein-protein interaction (PPI) network was constructed to further understand of relationship among target genes, compounds and proteins. Molecular docking was performed to investigate the binding ability between gypenosides and hub genes. A total of 70 targets for gypenosides and 804 targets for thyroid-associated ophthalmopathy were obtained with 8 common targets identified. GO analysis and KEGG pathway analysis revealed that the hub genes were enriched in JAK-STAT, while Reactome pathways analysis indicated genes enriched in interleukin pathways. PPI network showed STAT1, STAT3, and STAT4 were at the center. Additionally, molecular docking indicated that STAT1 and STAT3 display good binding forces with gypenosides. This study indicates that target genes mainly enriched in JAK-STAT signaling pathway, particularly in STATs, which can be combined with gypenosides. This may suggest that gypenosides have curative effect on thyroid-associated ophthalmopathy via the JAK-STAT pathway.

Astragaloside IV regulates differentiation and induces apoptosis of activated CD4+ T cells in the pathogenesis of experimental autoimmune encephalomyelitis

CD4⁺ T cells, especially T-helper (Th) cells (Th1, Th2 and Th17) and regulatory T cells (Treg) play pivotal role in the pathogenesis of multiple sclerosis (MS), a demyelinating autoimmune disease occurring in central nervous system (CNS). Astragaloside IV (ASI, CAS: 84687-43-4) is one of the saponins isolated from Astragalus membranceus, a traditional Chinese medicine with immunomodulatory effect. So far, whether ASI has curative effect on experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and how it affects the subsets of CD4⁺ T cells, as well as the underlying mechanism have not been clearly elucidated. In the present study, ASI was found to ameliorate the progression and hamper the recurrence of EAE effectively in the treatment regimens. It significantly reduced the demyelination and inflammatory infiltration of CNS in EAE mice by suppressing the percentage of Th1 and Th17 cells, which was closely associated with the inhibition of JAK/STAT and NF-κB signaling pathways. ASI also increased the percentage of Treg cells in spleen and CNS, which was accompanied by elevated Foxp3. However, in vitro experiments disclosed that ASI could regulate the differentiation of Th17 and Treg cells but not Th1 cells. In addition, it induced the apoptosis of MOG-stimulated CD4⁺ T cells probably through modulating STAT3/Bcl-2/Bax signaling pathways. Together, our findings suggested that ASI can modulate the differentiation of autoreactive CD4⁺ T cells and is a potential prodrug or drug for the treatment of MS and other similar autoimmune diseases.

Ibrutinib suppresses LPS-induced neuroinflammatory responses in BV2 microglial cells and wild-type mice

Background

The FDA-approved small-molecule drug ibrutinib is an effective targeted therapy for patients with chronic lymphocytic leukemia (CLL). Ibrutinib inhibits Bruton’s tyrosine kinase (BTK), a kinase involved in B cell receptor signaling. However, the potential regulation of neuroinflammatory responses in the brain by ibrutinib has not been comprehensively examined.

Methods

BV2 microglial cells were treated with ibrutinib (1 μM) or vehicle (1% DMSO), followed by lipopolysaccharide (LPS; 1 μg/ml) or PBS. RT-PCR, immunocytochemistry, and subcellular fractionation were performed to examine the effects of ibrutinib on neuroinflammatory responses. In addition, wild-type mice were sequentially injected with ibrutinib (10 mg/kg, i.p.) or vehicle (10% DMSO, i.p.), followed by LPS (10 mg/kg, i.p.) or PBS, and microglial and astrocyte activations were assessed using immunohistochemistry.

Results

Ibrutinib significantly reduced LPS-induced increases in proinflammatory cytokine levels in BV2 microglial and primary microglial cells but not in primary astrocytes. Ibrutinib regulated TLR4 signaling to alter LPS-induced proinflammatory cytokine levels. In addition, ibrutinib significantly decreased LPS-induced increases in p-AKT and p-STAT3 levels, suggesting that ibrutinib attenuates LPS-induced neuroinflammatory responses by inhibiting AKT/STAT3 signaling pathways. Interestingly, ibrutinib also reduced LPS-induced BV2 microglial cell migration by inhibiting AKT signaling. Moreover, ibrutinib-injected wild-type mice exhibited significantly reduced microglial/astrocyte activation and COX-2 and IL-1β proinflammatory cytokine levels.

Conclusions

Our data provide insights on the mechanisms of a potential therapeutic strategy for neuroinflammation-related diseases.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1308-0) contains supplementary material, which is available to authorized users.

Gypenosides improve diabetic cardiomyopathy by inhibiting ROS-mediated NLRP3 inflammasome activation

NLRP3 inflammasome activation plays an important role in diabetic cardiomyopathy (DCM), which may relate to excessive production of reactive oxygen species (ROS). Gypenosides (Gps), the major ingredients of Gynostemma pentaphylla (Thunb.) Makino, have exerted the properties of anti-hyperglycaemia and anti-inflammation, but whether Gps improve myocardial damage and the mechanism remains unclear. Here, we found that high glucose (HG) induced myocardial damage by activating the NLRP3 inflammasome and then promoting IL-1β and IL-18 secretion in H9C2 cells and NRVMs. Meanwhile, HG elevated the production of ROS, which was vital to NLRP3 inflammasome activation. Moreover, the ROS activated the NLRP3 inflammasome mainly by cytochrome c influx into the cytoplasm and binding to NLRP3. Inhibition of ROS and cytochrome c dramatically down-regulated NLRP3 inflammasome activation and improved the cardiomyocyte damage induced by HG, which was also detected in cells treated by Gps. Furthermore, Gps also reduced the levels of the C-reactive proteins (CRPs), IL-1β and IL-18, inhibited NLRP3 inflammasome activation and consequently improved myocardial damage in vivo. These findings provide a mechanism that ROS induced by HG activates the NLRP3 inflammasome by cytochrome c binding to NLRP3 and that Gps may be potential and effective drugs for DCM via the inhibition of ROS-mediated NLRP3 inflammasome activation.

Picroside II Attenuates CCI-Induced Neuropathic Pain in Rats by Inhibiting Spinal Reactive Astrocyte-Mediated Neuroinflammation Through the NF-κB Pathway

Reactive astrocyte-mediated neuroinflammatory responses in the spinal dorsal horn have been reported to play a pivotal role in pathological pain. Chronic constriction injury (CCI) enhances the activation of nuclear factor kappa B (NF-κB), which is involved in neuropathic pain (NP). Picroside II (PII), a major active component of Picrorhiza scrophulariiflora, has been investigated for its anti-oxidative, anti-inflammatory, and anti-apoptotic activities. Here, we explored the analgesic effects of PII on a model of CCI-induced NP and investigated the levels of the GFAP protein and the mRNA and protein levels of pro-inflammatory cytokines in the spinal cord, including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). CCI significantly induced mechanical allodynia and thermal hyperalgesia. Intraperitoneal administration of PII remarkably reversed the CCI-induced mechanical allodynia and thermal hyperalgesia and reduced the mRNA and protein levels of IL-1β, IL-6, and TNF-α in the spinal cord. Additionally, according to the in vitro data, the PII treatment inhibited LPS-induced increases in the mRNA and protein levels of IL-1β, IL-6, and TNF-α and suppressed the NF-κB pathway by inhibiting the phosphorylation of NF-κB/p65 and the degradation of inhibitor of NF-κB (IκB) in astrocytes without toxicity to astrocytes. Overall, the analgesic effect of PII correlated with the inhibition of spinal reactive astrocyte-mediated neuroinflammation through the NF-κB pathway in rats with NP.

The Neuroglial Dialog Between Cannabinoids and Hemichannels

The formation of gap junctions was initially thought to be the central role of connexins, however, recent evidence had brought to light the high relevance of unopposed hemichannels as an independent mechanism for the selective release of biomolecules during physiological and pathological conditions. In the healthy brain, the physiological opening of astrocyte hemichannels modulates basal excitatory synaptic transmission. At the other end, the release of potentially neurotoxic compounds through astroglial hemichannels and pannexons has been insinuated as one of the functional alterations that negatively affect the progression of multiple brain diseases. Recent insights in this matter have suggested encannabinoids (eCBs) as molecules that could regulate the opening of these channels during diverse conditions. In this review, we discuss and hypothesize the possible interplay between the eCB system and the hemichannel/pannexon-mediated signaling in the inflamed brain and during event of synaptic plasticity. Most findings indicate that eCBs seem to counteract the activation of major neuroinflammatory pathways that lead to glia-mediated production of TNF-α and IL-1β, both well-known triggers of astroglial hemichannel opening. In contrast to the latter, in the normal brain, eCBs apparently elicit the Ca²⁺-activation of astrocyte hemichannels, which could have significant consequences on eCB-dependent synaptic plasticity.