Micheliolide suppresses LPS-induced neuroinflammatory responses

Navigating IL-6: From molecular mechanisms to therapeutic breakthroughs

This concise review navigates the intricate realm of Interleukin-6 (IL-6), an important member of the cytokine family. Beginning with an introduction to cytokines, this narrative review unfolds with the historical journey of IL-6, illuminating its evolving significance. A crucial section unravels the three distinct signaling modes employed by IL-6, providing a foundational understanding of its versatile interactions within cellular landscapes. Moving deeper, the review meticulously dissects IL-6's signaling mechanisms, unraveling the complexities of its pleiotropic effects in both physiological responses and pathological conditions. A significant focus is dedicated to the essential role IL-6 plays in inflammatory diseases, offering insights into its associations and implications for various health conditions. The review also takes a therapeutic turn by exploring the emergence of anti-IL-6 monoclonal inhibitors, marking a profound stride in treatment modalities. Diving into the molecular realm, the review explores small molecules as agents for IL-6 inhibition, providing a nuanced perspective on diverse intervention strategies. As the review embarks on the final chapters, it contemplates future aspects, offering glimpses into potential research trajectories and the evolving landscape of IL-6-related studies.

Pharmacological potential of micheliolide: A focus on anti-inflammatory and anticancer activities

Micheliolide (MCL) is a chief constituent of plants such as Magnolia grandiflora L., Michelia compressa (Maxim.) Sarg. and Michelia champaca L. It is known to exhibit significant anticancer activity by various scientific investigations. This review aims to emphasize the anticancer and antiinflammatory activities of MCL. In this review, we summarized the published data in peer-reviewed manuscripts published in English. Our search was based on the following scientific search engines and databases: Scopus, Google Scholar, ScienceDirect, Springer, PubMed, and SciFinder, MCL possesses a broad spectrum of medicinal properties like other sesquiterpene lactones. The anticancer activity of this compound may be attributed to the modulation of several signaling cascades (PI3K/Akt and NF-κB pathways). It also induces apoptosis by arresting the cell cycle at the G1/G0 phase, S phase, and G2/M phase in many cancer cell lines. Very little data is available on its modulatory action on other signaling cascades like MAPK, STAT3, Wnt, TGFβ, Notch, EGFR, etc. This compound can be potentiated as a novel anticancer drug after thorough investigations in vitro, in vivo, and in silico-based studies.

Synthesis and Anti-Inflammatory Activity of Ferulic Acid-Sesquiterpene Lactone Hybrids

Acute lung injury (ALI) is a respiratory failure disease associated with high mortality rates in patients. The primary pathological damage is attributed to the excessive release of pro-inflammatory mediators in pulmonary tissue. However, specific therapy for ALI has not been developed. In this study, a series of novel ferulic acid-parthenolide (FA-PTL) and ferulic acid-micheliolide (FA-MCL) hybrid derivatives were designed, synthesized, and evaluated for their anti-inflammatory activities in vitro. Compounds 2, 4, and 6 showed pronounced anti-inflammatory activity against LPS-induced expression of pro-inflammatory cytokines in vitro. Importantly, compound 6 displayed good water solubility, and treatment of mice with compound 6 (10 mg/kg) significantly prevented weight loss and ameliorated inflammatory cell infiltration and edema in lung tissue, as well as improving the alveolar structure. These results suggest that compound 6 (((1aR,7aS,8R,10aS,10bS,E)-8-((dimethylamino)methyl)-1a-methyl-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(4-hydroxy-3-methoxyphenyl)acrylate 2-hydroxypropane-1,2,3-tricarboxylate) might be considered as a lead compound for further evaluation as a potential anti-ALI agent.

Micheliolide prevents estrogen deficiency-induced bone loss via inhibiting osteoclast bone resorption

Osteoporosis is one of the major health problems characterized by decreased bone density and increased risk of fractures. Nowadays, the treating strategies against osteoporosis are efficient, but still have some drawbacks. Micheliolide, a guaianolide sesquiterpene lactone isolated from Michelia compressa and Michelia champac, has been reported to have anti-inflammatory effects. Here, our data suggest that Micheliolide could protect mice from ovariectomy induced bone loss. According to the Micro-CT scan and histomorphometry quantification data, Micheliolide treatment inhibits excessive osteoclast bone resorption without affecting bone formation in estrogen deficiency mice. Consistently, our data suggest that Micheliolide could inhibit osteoclastogenesis in vitro. Additionally, we confirmed that Micheliolide inhibits osteoclasts formation via inhibiting P38 MAPK signaling pathway, and P79350 (a P38 agonist) could rescue this effect. In summary, our data suggest that Micheliolide could ameliorate estrogen deficiency-induced bone loss via attenuating osteoclastogenesis. Hence, Micheliolide could be used as a novel anti-resorptive agent against osteoporosis.

Effects of Natural Product-Derived Compounds on Inflammatory Pain via Regulation of Microglial Activation

Inflammatory pain is a type of pain caused by tissue damage associated with inflammation and is characterized by hypersensitivity to pain and neuroinflammation in the spinal cord. Neuroinflammation is significantly increased by various neurotransmitters and cytokines that are expressed in activated primary afferent neurons, and it plays a pivotal role in the development of inflammatory pain. The activation of microglia and elevated levels of pro-inflammatory cytokines are the hallmark features of neuroinflammation. During the development of neuroinflammation, various intracellular signaling pathways are activated or inhibited in microglia, leading to the regulation of inflammatory proteins and cytokines. Numerous attempts have been conducted to alleviate inflammatory pain by inhibiting microglial activation. Natural products and their compounds have gained attention as potential candidates for suppressing inflammatory pain due to verified safety through centuries of use. Many studies have also shown that natural product-derived compounds have the potential to suppress microglial activation and alleviate inflammatory pain. Herein, we review the literature on inflammatory mediators and intracellular signaling involved in microglial activation in inflammatory pain, as well as natural product-derived compounds that have been found to suppress microglial activation. This review suggests that natural product-derived compounds have the potential to alleviate inflammatory pain through the suppression of microglial activation.

Integrating network pharmacology and pharmacological validation to explore the effect of Shi Wei Ru Xiang powder on suppressing hyperuricemia

ETHNOPHARMACOLOGICAL RELEVANCE

Shi Wei Ru Xiang powder (SWR) is a traditional Tibetan medicinal formula with the effect of dispelling dampness and dispersing cold. In clinical practice, SWR is generally used for the treatment of hyperuricemia (HUA). However, its exact pharmacological mechanism remains unclear.

AIMS OF THE STUDY

To preliminarily elucidate the regulatory effects and possible mechanisms of SWR on hyperuricemia using network pharmacology and experimental validation.

MATERIALS AND METHODS

A mouse model of hyperuricemia was used to evaluate the alleviating effect of SWR on hyperuricemia. The major components of SWR were acquired by UPLC-Q/TOF-MS. The potential molecular targets and associated signaling pathways were predicted through network pharmacology. The mechanism of action of SWR in ameliorating hyperuricemia was further investigated by pharmacological evaluation.

RESULTS

Mice with hyperuricemia and renal dysfunction were ameliorated by SWR. The 36 components of SWR included phenolic acids, terpenoids, alkaloids and flavonoids were identified. Network pharmacological analysis showed the involvement of the above compounds, and 115 targets were involved to treat hyperuricemia, involving multiple biological processes and different signaling pathways. Pharmacological experiments validated that SWR ameliorated hyperuricemic nephropathy in mice by modulating the mitogen-activated protein kinase (MAPK) signaling pathway, nuclear factor kappaB (NF-κB) signaling pathway and NOD-like receptor signaling pathway.

CONCLUSION

MAPK signaling pathway, NF-κB signaling pathway and NOD-like receptor signaling pathway play important roles in the therapeutic effects of SWR on hyperuricemia.

Sesquiterpene Lactones and Cancer: New Insight into Antitumor and Anti-inflammatory Effects of Parthenolide-Derived Dimethylaminomicheliolide and Micheliolide

Applied science nowadays works on the isolation and application of biological macromolecules (BMM). These BMM are isolates from plants using different techniques and used as anticancer, antimicrobial, and anti-inflammatory drugs. Parthenolide (PLT) is one of the most important biological macromolecules and a naturally occurring sesquiterpene lactone that is isolated from a plant species Tanacetum parthenium (T. parthenium). The anti-cancer and anti-inflammatory effects of PTL isolated from T. parthenium were previously reported and summarized in detail. These biological activities make it a vital candidate for further researches and drugs development. As per the previously obtained findings, the sesquiterpene is very much known for some biological activities; therefore, the anti-cancer and anti-inflammatory activities of the sesquiterpene were critically reviewed. During the research process, PTL was found to be unstable in both acidic and basic conditions with low solubility, so structurally related compounds micheliolide (MCL) and Dimethylaminomicheliolide (DMAMCL) (a prodrug of MCL) were developed. In this article, we briefly review the therapeutic effects of PTL and its derivative DMAPT on inflammatory diseases and tumors, focusing on the current application of PTL in targeted therapy and combination therapy, together with anti-inflammatory and anti-tumor functions of MCL and DMAMCL. The uniqueness of this biological macromolecule is not to harm the normal cell but target the cancerous cells. Therefore, the current literature review might be helpful and useful for prospects based on the effects of MCL and DMAMCL on cancer.

ACT001 attenuates microglia-mediated neuroinflammation after traumatic brain injury via inhibiting AKT/NFκB/NLRP3 pathway

Background

Microglia-mediated neuroinflammatory response following traumatic brain injury (TBI) is considered as a vital secondary injury factor, which drives trauma-induced neurodegeneration and is lack of efficient treatment. ACT001, a sesquiterpene lactone derivative, is reportedly involved in alleviation of inflammatory response. However, little is known regarding its function in regulating innate immune response of central nervous system (CNS) after TBI. This study aimed to investigate the role and underlying mechanism of ACT001 in TBI.

Methods

Controlled cortical impact (CCI) models were used to establish model of TBI. Cresyl violet staining, evans blue extravasation, neurobehavioral function assessments, immunofluorescence and transmission electron microscopy were used to evaluate therapeutic effects of ACT001 in vivo. Microglial depletion was induced by administering mice with colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622. Cell-cell interaction models were established as co-culture system to simulate TBI conditions in vitro. Cytotoxic effect of ACT001 on cell viability was assessed by cell counting kit-8 and activation of microglia cells were induced by Lipopolysaccharides (LPS). Pro-inflammatory cytokines expression was determined by Real-time PCR and nitric oxide production. Apoptotic cells were detected by TUNEL and flow cytometry assays. Tube formation was performed to evaluate cellular angiogenic ability. ELISA and western blot experiments were used to determine proteins expression. Pull-down assay was used to analyze proteins that bound ACT001.

Results

ACT001 relieved the extent of blood-brain barrier integrity damage and alleviated motor function deficits after TBI via reducing trauma-induced activation of microglia cells. Delayed depletion of microglia with PLX5622 hindered therapeutic effect of ACT001. Furthermore, ACT001 alleviated LPS-induced activation in mouse and rat primary microglia cells. Besides, ACT001 was effective in suppressing LPS-induced pro-inflammatory cytokines production in BV2 cells, resulting in reduction of neuronal apoptosis in HT22 cells and improvement of tube formation in bEnd.3 cells. Mechanism by which ACT001 functioned was related to AKT/NFκB/NLRP3 pathway. ACT001 restrained NFκB nuclear translocation in microglia cells through inhibiting AKT phosphorylation, resulting in decrease of NLRP3 inflammasome activation, and finally down-regulated microglial neuroinflammatory response.

Conclusions

Our study indicated that ACT001 played critical role in microglia-mediated neuroinflammatory response and might be a novel potential chemotherapeutic drug for TBI.

Autophagy Induced by Micheliolide Alleviates Acute Irradiation-Induced Intestinal Injury via Inhibition of the NLRP3 Inflammasome

Radiation-induced enteropathy (RIE) is one of the most common and fatal complications of abdominal radiotherapy, with no effective interventions available. Pyroptosis, a form of proinflammatory regulated cell death, was recently found to play a vital role in radiation-induced inflammation and may represent a novel therapeutic target for RIE. To investigate this, we found that micheliolide (MCL) exerted anti-radiation effects in vitro. Therefore, we investigated both the therapeutic effects of MCL in RIE and the possible mechanisms by which it may be therapeutic. We developed a mouse model of RIE by exposing C57BL/6J mice to abdominal irradiation. MCL treatment significantly ameliorated radiation-induced intestinal tissue damage, inflammatory cell infiltration, and proinflammatory cytokine release. In agreement with these observations, the beneficial effects of MCL treatment in RIE were abolished in Becn1^+/− mice. Furthermore, super-resolution microscopy revealed a close association between NLR pyrin domain three and lysosome-associated membrane protein/light chain 3-positive vesicles following MCL treatment, suggesting that MCL facilitates phagocytosis of the NLR pyrin domain three inflammasome. In summary, MCL-mediated induction of autophagy can ameliorate RIE by NLR pyrin domain three inflammasome degradation and identify MCL as a novel therapy for RIE.

Interference with long noncoding RNA SNHG3 alleviates cerebral ischemia-reperfusion injury by inhibiting microglial activation

Neuroinflammation plays a strong part in cerebral ischemia-reperfusion injury, and microglial activation is regarded as a marker for neuroinflammation. Long noncoding RNA small nucleolar RNA host gene 3 (lncRNA SNHG3) is heavily expressed in cerebral ischemia-reperfusion models, but its mechanism is rarely studied. This study aims to explore whether SNHG3 is involved in cerebral ischemia-reperfusion injury by promoting microglial activation and inflammatory factor secretion. Activation of microglia was induced through oxygen-glucose deprivation/reoxygenation (OGD/R) or LPS and the cerebral ischemia-reperfusion injury in mice was induced by transient middle cerebral artery occlusion (tMCAO). Levels of SNHG3, IL-6, and TNF-α were determined by quantitative real-time PCR. Immunofluorescence was used for the detection of Iba-1 expression. Western blot was carried out for the detection of Iba-1 and histone deacetylase 3 (HDAC3) protein levels. An ELISA was performed to detect TNF-α and IL-6 levels. RNA pull-down, RNA immunoprecipitation, and co-Immunoprecipitation assays were conducted to detect the binding between SNHG3 and HDAC3. A H&E staining assay was applied to observe pathologic changes. Microglial activation was observed with immunohistochemistry. Levels of SNHG3, microglial activation marker Iba-1, proinflammatory factors (TNF-α and IL-6) were highly expressed in cell models (treated with OGD/R or LPS) and mouse models (tMCAO). Besides, SNHG3 could bind to HDAC3 and promote its expression. Through further study, we found that SNHG3 could stabilize the protein levels of HDAC3 and inhibit the ubiquitination of HDAC3. Furthermore, interference with SNHG3 down-regulated the levels of HDAC3, Iba-1, TNF-α, and IL-6, whereas the overexpression of HDAC3 reversed the results. The H&E staining assay demonstrated that the condition of vacuoles of different sizes, uneven cytoplasmic staining, and inflammatory infiltration in the brain tissue was improved by interference with SNHG3. The immunohistochemistry result showed that microglial activation marker Iba-1 was increased in the shRNA-SNHG3 group, indicating that interference with SNHG3 inhibited the activation of microglia in the brain. LncRNA SNHG3 aggravated cerebral ischemia-reperfusion injury by promoting the activation of microglia, increasing the levels of HDAC3, and the secretion of inflammatory factors.

Sesquiterpene Lactones: Promising Natural Compounds to Fight Inflammation

Inflammation is a crucial and complex process that reestablishes the physiological state after a noxious stimulus. In pathological conditions the inflammatory state may persist, leading to chronic inflammation and causing tissue damage. Sesquiterpene lactones (SLs) are composed of a large and diverse group of highly bioactive plant secondary metabolites, characterized by a 15-carbon backbone structure. In recent years, the interest in SLs has risen due to their vast array of biological activities beneficial for human health. The anti-inflammatory potential of these compounds results from their ability to target and inhibit various key pro-inflammatory molecules enrolled in diverse inflammatory pathways, and prevent or reduce the inflammatory damage on tissues. Research on the anti-inflammatory mechanisms of SLs has thrived over the last years, and numerous compounds from diverse plants have been studied, using in silico, in vitro, and in vivo assays. Besides their anti-inflammatory potential, their cytotoxicity, structure–activity relationships, and pharmacokinetics have been investigated. This review aims to gather the most relevant results and insights concerning the anti-inflammatory potential of SL-rich extracts and pure SLs, focusing on their effects in different inflammatory pathways and on different molecular players.

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.

Natural compounds against cytotoxic drug-induced cardiotoxicity: A review on the involvement of PI3K/Akt signaling pathway

Cardiotoxicity is a critical concern in the use of several cytotoxic drugs. Induction of apoptosis, inflammation, and autophagy following dysregulation of the PI3K/Akt signaling pathway contributes to the cardiac damage induced by these drugs. Several natural compounds (NCs), including ferulic acid, gingerol, salvianolic acid B, paeonol, apigenin, calycosin, rutin, neferine, higenamine, vincristine, micheliolide, astragaloside IV, and astragalus polysaccharide, have been reported to suppress cytotoxic drug-induced cardiac injury. This article reviews these NCs that have been reported to have a protective effect against cytotoxic drug-induced cardiotoxicity through regulation of the PI3K/Akt signaling pathway.

The potential role of sesquiterpene lactones isolated from medicinal plants in the treatment of the metabolic syndrome - A review

Metabolic syndrome comprises a cluster of metabolic disorders related to the development of cardiovascular disease and type 2 diabetes mellitus. In latter years, plant secondary metabolites have become of special interest because of their potential role in preventing and managing metabolic syndrome. Sesquiterpene lactones constitute a large and diverse group of biologically active compounds widely distributed in several medicinal plants used for the treatment of metabolic disorders. The structural diversity and the broad spectrum of biological activities of these compounds drew significant interests in the pharmacological applications. This review describes selected sesquiterpene lactones that have been experimentally validated for their biological activities related to risk factors of metabolic syndrome, together with their mechanisms of action. The potential beneficial effects of sesquiterpene lactones discussed in this review demonstrate that these substances represent remarkable compounds with a diversity of molecular structure and high biological activity, providing new insights into the possible role in metabolic syndrome management.

Micheliolide alleviates ankylosing spondylitis (AS) by suppressing the activation of the NLRP3 inflammasome and maintaining the balance of Th1/Th2 via regulating the NF-κB signaling pathway

Background

Ankylosing spondylitis (AS) is a common form of inflammatory arthritis. Micheliolide (MCL), a sesquiterpene lactone, is reportedly involved in the alleviation of inflammatory response. This study aimed to investigate the mechanism of MCL in the treatment of AS.

Methods

Mice were randomly divided into five groups: the sham group, the MCL (50 mg/kg) group, the AS model group, the AS + MCL (20 mg/kg) group, and the AS + MCL (50 mg/kg) group. After the addition of the inhibitor celastrol, mice were randomly divided into five groups: the sham group, the AS model group, the AS + MCL (50 mg/kg) group, the AS + Celastrol (1 mg/kg) group, and the AS + Celastrol (1 mg/kg) + MCL (50 mg/kg) group.

Results

Compared with the AS model mice, the protein expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-18 were decreased after MCL treatment. The protein expression levels of capase-1 p10, IL-1β p17, NOD-like receptor family and pyrin domain containing 3 (NLRP3), caspase-1, and apoptosis-associated speck-like protein (ASC) were also reduced. The protein expression levels of Interferon (IFN)-γ were down-regulated, but levels of IL-4 were increased. Western blotting and immunohistochemistry revealed that the levels of p-IκB α were up-regulated, while the levels of phosphorylated-p65 were down-regulated. After the addition of celastrol, MCL treatment significantly reduced the levels of p-p65, NLRP3, caspase-1, and ASC. Meanwhile, the levels of IFN-γ were markedly down-regulated, but the levels of IL-4 were enhanced.

Conclusions

Our study found that MCL suppressed the activation of NLRP3 inflammasome and maintained the balance of Th1/Th2 via regulating NF-κB signaling. Therefore, MCL could potentially be used to treat AS.

Neuroprotective effects of natural compounds on LPS-induced inflammatory responses in microglia

Neuroinflammation is one of the main mechanisms involved in the progression of neurodegeneration. The activation of microglia is the main feature of neuroinflammation, promoting the release of neurotoxic molecules and pro-inflammatory cytokines and resulting in the progressive neuronal cell death. Thus, suppression of the over-activation of microglia using novel pharmacological agents is an attractive issue to alleviate the neuroinflammatory processes associated with neurodegeneration. In recent years, medicinal plants-derived natural compounds have received extensive attention as useful sources of new neuroprotective agents for treating neurological disorders. In this review, we summarized the detailed research progress on the natural compounds derived from medicinal plants with potential anti-inflammatory effects and their molecular mechanisms on modulating the LPS-induced inflammatory responses in microglia. The natural compounds that efficacious in inhibiting the microglia activation include flavonoids, glycosides, phenolics, terpenoids, quinones, alkaloids, lignans, coumarins, chalcone, stilbene and others (biphenyl, phenylpropanoid, oxy carotenoid). They can reduce the expression of neurotoxic mediators (NO, PGE2, iNOS, COX-2) and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β), down-regulate inflammatory markers and prevent neural damage. They exert anti-neuroinflammatory effects by modulating relevant signaling pathways (NF-κB, MAPKs, Nrf2/HO-1, PI3K/Akt, JAK/STAT) as demonstrated by experimental data. The present work reviews the role of microglia activation in neuroinflammation, highlighting the potential anti-inflammatory effects of natural compounds as a promising approach to develop innovative neuroprotective strategy.

Long-term every-other-day administration of DMAMCL has little effect on aging and age-associated physiological decline in mice

The activation of transcription factor NF-κB is currently identified as one of the driving forces to the aging process. Genetic impairment of NF-κB signaling pathway or pharmacological inhibition of NF-κB activity has been shown to extend healthspan and lifespan in animal models, and delay or reduce many age-related symptoms. However, the aging intervention strategies based on NF-κB inhibition by the suitable small molecular compound is currently still lacking. The water-soluble dimethylaminomicheliolide (DMAMCL), can inhibit NF-κB activity and is currently undergoing clinical trials. In this study, we showed that 15 months of DMAMCL administration started in 1-year old male mice was well-tolerated and safe, and improved or had little effect on some age-associated symptoms, such as neurobehavioral phenotypes, physical performance, cardiac function, hematological parameters, immune aging phenotypes, clinical chemistry parameters, and glucose homeostasis. At the molecular level, DMAMCL administration mitigated serum levels of several age-associated inflammatory cytokines, including IL-6, IL-1α, IL-1β, TNF-α, IFN-γ, and CXCL2, and inhibited NF-κB activity in several aged tissues. Collectively, our results indicate that current strategy of DMAMCL administration may has little effect on aging process in mice, and provide basic clues to further exploit the possibility of DMAMCL-based aging intervention to promote healthy aging.

ACT001 reduces the expression of PD-L1 by inhibiting the phosphorylation of STAT3 in glioblastoma

ACT001, which is derived from an ancient anti-inflammatory drug, has been shown to cross the blood-brain barrier in preclinical studies and has demonstrated anti-glioblastoma (GBM) activity in clinical trials. However, its pharmacological potential for anti-GBM immune response modulation remains unclear. The chemical structure of ACT001 indicates that it may bind to STAT3 and thus modulate antitumor immune response. Methods: Bioinformatics and immunohistochemistry (IHC) were used to assess STAT3 and PD-L1 expression in gliomas. Western blotting, RT-PCR and immunofluorescence were used to detect PD-L1 and p-STAT3 expression in glioma cells exposed to ACT001. Chromatin immunoprecipitation, an ACT001-Biotin probe, and a dual-luciferase reporter assay were used to detect direct modulation. The in vivo efficacy of ACT001 was evaluated in GL261 murine glioma model. Survival analyses were conducted using the log-rank (Mantel-Cox) test. Results: Bioinformatic analysis of 1,837 samples from 4 public glioma datasets showed that STAT3 mRNA expression was correlated with the degree of malignancy and therapeutic resistance and that STAT3 mRNA expression was related to immunosuppression, leukocyte infiltration, and PD-L1 expression. IHC staining of 53 tissue samples confirmed that relatively high phosphorylated STAT3 and PD-L1 protein expression was associated with a relatively advanced World Health Organization (WHO) glioma grade. Next, we confirmed that ACT001 treatment reduced PD-L1 expression and STAT3 phosphorylation. An ACT001-biotin probe was used to verify that ACT001 bound to STAT3. We also demonstrated that STAT3 bound to the PD-L1 promoter. The inhibition of PD-L1 expression and STAT3 phosphorylation by ACT001 could be rescued by STAT3 overexpression. Additionally, ACT001 inhibited GBM growth and decreased PD-L1 expression in vivo. The expression of the M2 markers CD206 and CD163 was decreased, while that of the antitumor immune markers iNOS and IFNγ was increased by ACT001 in vivo. Conclusion: Our results demonstrate that STAT3 plays a key role in immunosuppression of glioma and is inhibited by ACT001. ACT001 inhibits PD-L1 transcription and modulates anti-tumor immune response in glioma bearing mice. These findings will help us to understand the mechanism of ACT001 in GBM therapy.

The aqueous extract of Phellinus igniarius (SH) ameliorates dextran sodium sulfate-induced colitis in C57BL/6 mice

Phellinus igniarius, which is called Sanghuang in Chinese, is a fungal herb widely used in Traditional Chinese Medicine to treat stomachache, inflammation and tumors. Recent studies have demonstrated the antitumor, anti-diabetic, anti-inflammatory and immunity-modulating activities of P. igniarius. In the present study, we investigated that ameliorating effect of the aqueous extract of P. igniarius fruiting body (SH) on dextran sodium sulfate (DSS)-induced colitis in C57BL/6 mice. Treatment with SH (250 and 400 mg/kg) for 8 weeks effectively alleviated the pathological indicators of colitis such as bodyweight reduction, disease activity index score, shortening of colon length and abnormal colon histology. The plasma levels of lipopolysaccharide (LPS) and inflammatory factors such as interleukin-6 (IL-6), IL-1β and tumor necrosis factor (TNF)-α were all significantly reduced. Supplementation of SH (10 mg/L) also inhibited LPS-elicited IL-1β production by RAW264.7 macrophages. Real-time PCR and western blot showed that treatment with SH significantly inhibited the phosphorylation of nuclear factor kappa B inhibitor alpha (IκBα) and decreased the expression of IL-6/IL-1β-maturation genes such as apoptosis-associated speck-like protein (ASC3) and caspase-1 in the colon of DSS-induced colitis mice. These results suggest that SH is adequate for the treatment of colitis. Inhibiting the expression and release of inflammatory factors may participate in the colitis-ameliorating effect of SH.

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.

Desoxo-narchinol A and Narchinol B Isolated from Nardostachys jatamansi Exert Anti-neuroinflammatory Effects by Up-regulating of Nuclear Transcription Factor Erythroid-2-Related Factor 2/Heme Oxygenase-1 Signaling

We previously reported that desoxo-narchinol A and narchinol B from Nardostachys jatamansi DC (Valerianaceae) inhibited the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂), and the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein in lipopolysaccharide (LPS)-stimulated BV2 and primary microglial cells. In this study, we aimed to elucidate the molecular mechanism underlying the anti-neuroinflammatory effects of desoxo-narchinol A and narchinol B. These two compounds inhibited the nuclear factor (NF)-κB pathway, by repressing the phosphorylation and degradation of inhibitor kappa B (IκB)-α, nuclear translocation of the p65/p50 heterodimer, and DNA-binding activity of the p65 subunit. Furthermore, both compounds induced heme oxygenase-1 (HO-1) protein expression, which was mediated by the activation of nuclear transcription factor erythroid-2-related factor 2 (Nrf2). Activation of the Nrf2/HO-1 pathway by desoxo-narchinol A was shown to be regulated by increased phosphorylation of p38 and extracellular signal-regulated kinase (ERK), whereas only p38 was involved in narchinol B-induced activation of the Nrf2/HO-1 pathway. In addition, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling was also involved in the activation of HO-1 by desoxo-narchinol A and narchinol B. These compounds also increased the phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine-9 residue, following phosphorylation of Akt. The anti-neuroinflammatory effect of desoxo-narchinol A and narchinol B was partially blocked by a selective HO-1 inhibitor, suggesting that this effect is partly mediated by HO-1 induction. In addition, both compounds also induced HO-1 protein expression in rat-derived primary microglial cells, which was correlated with their anti-neuroinflammatory effects in LPS-stimulated primary microglial cells. In conclusion, desoxo-narchinol A and narchinol B are potential candidates for the development of preventive agents for the regulation of neuroinflammation in neurodegenerative diseases.