Eriocalyxin B ameliorates experimental autoimmune encephalomyelitis by suppressing Th1 and Th17 cells

Eriocalyxin B alleviated ischemic cerebral injury by limiting microglia-mediated excessive neuroinflammation in mice

Excessive neuroinflammation mediated by microglia has a detrimental effect on the progression of ischemic stroke. Eriocalyxin B (EriB) was found with a neuroprotective effect in mice with Parkinson's disease via the suppression of microglial overactivation. This study aimed to investigate the roles of EriB in permanent middle cerebral artery occlusion (pMCAO) mice. The pMCAO was induced in the internal carotid artery of the mice by the intraluminal filament method, and EriB (10 mg/kg) was administered immediately after surgery by intraperitoneal injection. The behavior score, 2,3,5-triphenyltetrazole chloride staining, Nissl staining, TUNEL, immunohistochemistry, immunofluorescence, PCR, ELISA, and immunoblotting revealed that EriB administration reduced brain infarct and neuron death and ameliorated neuroinflammation and microglia overactivation in pMCAO mice, manifested by alterations of TUNEL-positive cell numbers, ionized calcium binding adaptor molecule 1 (Iba-1)-positive cell numbers, and expression of tumor necrosis factor-α, interleukin 6, IL-1β, inducible nitric oxide synthase, and arginase 1. In addition, EriB suppressed ischemia-induced activation of nuclear factor kappa B (NF-κB) signaling in the brain penumbra, suggesting the involvement of NF-κB in EriB function. In conclusion, EriB exerted anti-inflammatory effects in ischemia stroke by regulating the NF-κB signaling pathway, and this may provide insights into the neuroprotective effect of EriB in the treatment of ischemic stroke.

Ethnobotanical, Phytochemical, and Pharmacological Properties of the Subfamily Nepetoideae (Lamiaceae) in Inflammatory Diseases

Nepetoideae is the most diverse subfamily of Lamiaceae, and some species are well known for their culinary and medicinal uses. In recent years, there has been growing interest in the therapeutic properties of the species of this group regarding inflammatory illnesses. This study aims to collect information on traditional uses through ethnobotanical, pharmacological, and phytochemical information of the subfamily Nepetoideae related to inflammatory diseases. UNAM electronic resources were used to obtain the information. The analysis of the most relevant literature was compiled and organised in tables. From this, about 106 species of the subfamily are traditionally recognised to alleviate chronic pain associated with inflammation. Pharmacological studies have been carried out in vitro and in vivo on approximately 308 species belonging to the genera Salvia, Ocimum, Thymus, Mentha, Origanum, Lavandula, and Melissa. Phytochemical and pharmacological evaluations have been performed and mostly prepared as essential oil or high polarity extracts, whose secondary metabolites are mainly of a phenolic nature. Other interesting and explored metabolites are diterpenes from the abietane, clerodane, and kaurane type; however, they have only been described in some species of the genera Salvia and Isodon. This review reveals that the Nepetoideae subfamily is an important source for therapeutics of the inflammatory process.

Investigation of targets and anticancer mechanisms of covalently acting natural products by functional proteomics

Eriocalyxin B (EB), 17-hydroxy-jolkinolide B (HJB), parthenolide (PN), xanthatin (XT) and andrographolide (AG) are terpenoid natural products with a variety of promising antitumor activities, which commonly bear electrophilic groups (α,β-unsaturated carbonyl groups and/or epoxides) capable of covalently modifying protein cysteine residues. However, their direct targets and underlying molecular mechanisms are still largely unclear, which limits the development of these compounds. In this study, we integrated activity-based protein profiling (ABPP) and quantitative proteomics approach to systematically characterize the covalent targets of these natural products and their involved cellular pathways. We first demonstrated the anti-proliferation activities of these five compounds in triple-negative breast cancer cell MDA-MB-231. Tandem mass tag (TMT)-based quantitative proteomics showed all five compounds commonly affected the ubiquitin mediated proteolysis pathways. ABPP platform identified the preferentially modified targets of EB and PN, two natural products with high anti-proliferation activity. Biochemical experiments showed that PN inhibited the cell proliferation through targeting ubiquitin carboxyl-terminal hydrolase 10 (USP10). Together, this study uncovered the covalently modified targets of these natural products and potential molecular mechanisms of their antitumor activities.

Eriocalyxin B ameliorated Crohn's disease-like colitis by restricting M1 macrophage polarization through JAK2/STAT1 signalling

BACKGROUND AND AIMS

M1 polarization of macrophages in the intestine is an important maintenance factor of the inflammatory response in Crohn's disease (CD). Eriocalyxin B (EriB) is a natural medicine that antagonizes inflammation. Our study aimed to determine the effects of EriB on CD-like colitis in mice, as well as the possible mechanism.

METHODS

2,4,6-trinitrobenzene sulfonic acid (TNBS) mice and Il-10^-/- mice were used as CD animal models, and the therapeutic effect of EriB on CD-like colitis in mice was addressed by the disease activity index (DAI) score, weight change, histological analysis and flow cytometry assay. To assess the direct role of EriB in regulating macrophage polarization, bone marrow-derived macrophages (BMDMs) were induced to M1 or M2 polarization separately. Molecular docking simulations and blocking experiments were performed to explore the potential mechanisms by which EriB regulates the macrophage polarization.

RESULTS

EriB treatment reduced body weight loss, DAI score and histological score, demonstrating the improvement of colitis symptoms in mice. In vivo and in vitro experiments both showed that EriB decreased the M1 polarization of macrophages, and suppressed the release of proinflammatory cytokines (IL-1β, TNF-α and IL-6) in mouse colons and BMDMs. The activation of Janus kinase 2/signal transducer and activator of transcription 1 (JAK2/STAT1) signals could be inhibited by EriB, which may be related to the regulation of EriB on M1 polarization.

CONCLUSIONS

EriB inhibits the M1 polarization of macrophages by attenuating the JAK2/STAT1 pathway, which partially explains the potential mechanism by which EriB ameliorates colitis in mice, and provides a new regimen for the clinical treatment of CD.

Di- and Triterpenoids from the Rhizomes of Isodon amethystoides and Their Anti-inflammatory Activities

Amethystoidesic acid (1), a triterpenoid with an unprecedented 5/6/6/6 tetracyclic skeleton, and six undescribed diterpenoids, amethystoidins A-F (2-7), were isolated from the rhizomes of Isodon amethystoides along with 31 known di- and triterpenoids (8-38). Their structures were fully elucidated via extensive spectroscopic analysis including 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and electronic circular dichroism (ECD) calculations. Compound 1 is the first example of a triterpenoid possessing a rare ring system (5/6/6/6) derived from a contracted A-ring and the 18,19-seco-E-ring of ursolic acid. Compounds 6, 16, 21, 22, 24, and 27 significantly inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, which could be partly mediated by the downregulation of LPS-induced inducible nitric oxide synthase (iNOS) protein expression.

Acidifiers Attenuate Diquat-Induced Oxidative Stress and Inflammatory Responses by Regulating NF-κB/MAPK/COX-2 Pathways in IPEC-J2 Cells

In this study, we evaluated the protective effects and potential mechanisms of acidifiers on intestinal epithelial cells exposure to oxidative stress (OS). IPEC-J2 cells were first pretreated with 5 × 10⁻⁵ acidifiers for 4 h before being exposed to the optimal dose of diquat to induce oxidative stress. The results showed that acidifiers attenuated diquat-induced oxidative stress, which manifests as the improvement of antioxidant capacity and the reduction in reactive oxygen species (ROS) accumulation. The acidifier treatment decreased cell permeability and enhanced intestinal epithelial barrier function through enhancing the expression of claudin-1 and occludin in diquat-induced cells. Moreover, acidifier treatment attenuated diquat-induced inflammatory responses, which was confirmed by the decreased secretion and gene expression of pro-inflammatory (TNF-α, IL-8) and upregulated anti-inflammatory factors (IL-10). In addition, acidifiers significantly reduced the diquat-induced gene and protein expression levels of COX-2, NF-κB, I-κB-β, ERK1/2, and JNK2, while they increased I-κB-α expression in IPEC-J2 cells. Furthermore, we discovered that acidifiers promoted epithelial cell proliferation (increased expression of PCNA and CCND1) and inhibited apoptosis (decreased expression of BAX, increased expression of BCL-2). Taken together, these results suggest that acidifiers are potent antioxidants that attenuate diquat-induced inflammation, apoptosis, and maintain cellular barrier integrity by regulating the NF-κB/MAPK/COX-2 signaling pathways.

Atom-precise fluorescent copper cluster for tumor microenvironment targeting and transient chemodynamic cancer therapy

BACKGROUND

Reactive oxygen species (ROS) have been widely studied for cancer therapy. Nevertheless, instability and aspecific damages to cellular biomolecules limit the application effect. Recently, significant research efforts have been witnessed in the flourishing area of metal nanoclusters (NCs) with atomically precise structures for targeted release of ROS but few achieved success towards targeting tumor microenvironment.

RESULTS

In this work, we reported an atomically precise nanocluster Cu6(C4H3N2S)6 (Cu6NC), which could slowly break and generate ROS once encountered with acidic. The as-prepared Cu6NC demonstrated high biological safety and efficient chemodynamic anti-tumor properties. Moreover, Cu6NC enabled transient release of ROS and contained targeting behavior led by the tumor microenvironment. Both in vitro and in vivo experiments confirmed that Cu6NC demonstrated a low cytotoxicity for normal cells, while presented high cytotoxicity for tumor cells with a concentration-dependent manner.

CONCLUSIONS

This work not only reported a promising candidate for chemodynamic cancer therapy, but also paved the route to address clinical issues at the atomic level.

Total Synthesis of Isorosthin L and Isoadenolin I

Total syntheses of two Isodon diterpenes, isorosthin L and isoadenolin I, are reported. The synthetic strategy features a quick assembly of two simple building blocks through a diastereoselective intermolecular aldol reaction and a subsequent radical cyclization for efficient construction of a rather complex advanced intermediate bearing a quaternary stereocenter present in all Isodon diterpenes. Oxidative cleavage of the C-C bond in the cyclopentane enabled the conversion to a lactone moiety which is desired for the construction of the molecular skeleton through reductive coupling with an aldehyde carbonyl group.

Natural Molecules Targeting Thioredoxin System and Their Therapeutic Potential

Significance: Thioredoxin (Trx) and thioredoxin reductase are two core members of the Trx system. The system bridges the gap between the universal reducing equivalent NADPH and various biological molecules and plays an essential role in maintaining cellular redox homeostasis and regulating multiple cellular redox signaling pathways. Recent Advance: In recent years, the Trx system has been well documented as an important regulator of many diseases, especially tumorigenesis. Thus, the development of potential therapeutic molecules targeting the system is of great significance for disease treatment. Critical Issues: We herein first discuss the physiological functions of the Trx system and the role that the Trx system plays in various diseases. Then, we focus on the introduction of natural small molecules with potential therapeutic applications, especially the anticancer activity, and review their mechanisms of pharmacological actions via interfering with the Trx system. Finally, we further discuss several natural molecules that harbor therapeutic potential and have entered different clinical trials. Future Directions: Further studies on the functions of the Trx system in multiple diseases will not only improve our understanding of the pathogenesis of many human disorders but also help develop novel therapeutic strategies against these diseases. Antioxid. Redox Signal. 34, 1083-1107.

Effect of Eriocalyxin B on prostatic inflammation and pelvic pain in a mouse model of experimental autoimmune prostatitis

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common disease in males. Eriocalyxin B (EriB), a natural diterpenoid purified from Isodon eriocalyx var. laxiflora, was previously reported to have antitumor effects via multiple immune-related pathways. In this study, we investigated the effect of EriB on CP/CPPS using a mouse model of experimental autoimmune prostatitis (EAP) and explored its potential mechanisms.

METHODS

The EAP model was established in nonobese diabetic mice by intradermal injecting a mixture of prostate antigens and Complete Freund's Adjuvant on days 0 and 28. Then, EAP mice received daily intraperitoneal injections of EriB (5 or 10 mg/kg/d) for 14 days, from days 28 to 42 (EAP+EriB5 or EAP+EriB10 groups). The histopathological appearance of the prostate tissues was evaluated. Chronic pelvic pain development was assessed by cutaneous allodynia. Inflammatory cytokines were measured by enzyme-linked immunosorbent assay tests. We then explored anti-inflammatory potential mechanisms of EriB by studying the effects of PI3K inhibitor wortmannin (EAP+EriB10+Wort group) and NF-κB inhibitor SC75741 (EAP+EriB10+SC group) on prostate inflammation and pelvic pain using this model.

RESULTS

Histological analyses revealed significant prostate inflammation in EAP mice compared with control mice. Significantly increased pelvic pain was detected in EAP mice (P < .05). Compared with the EAP+Veh group, chronic pain development, histological appearance, and cytokine levels demonstrated that EriB could alleviate the severity of EAP in a dose-dependent manner though upregulation of the PI3K/Akt/mTOR pathway and downregulation of the NF-κB pathway. Further mechanism research demonstrated that the PI3K/AKT/mTOR pathway could be blocked by wortmannin, but was not affected by SC75741. In addition, the NF-κB pathway could be further inhibited by SC75741 compared with the EAP+EriB10+Veh group. However, wortmannin could reactivate the NF-κB pathway, indicating that the PI3K/AKT/mTOR pathway negatively regulates the NF-κB pathway during EriB treatment.

CONCLUSIONS

The results of the present study suggested that EriB could alleviate the severity of prostatic inflammation and pelvic pain in an EAP mouse model. These findings may broaden the value of EriB as a promising candidate for the treatment of CP/CPPS.

Eriodictyol suppresses Th17 differentiation and the pathogenesis of experimental autoimmune encephalomyelitis

T helper 17 (Th17) cells that express interleukin-17 (IL-17) play a key role in various inflammatory diseases, such as multiple sclerosis (MS), and its animal model experimental autoimmune encephalomyelitis (EAE). The retinoic acid receptor-related orphan receptors γt (RORγt) have an indispensable effect on the differentiation of this cell type, and are thus considered a valuable target in the treatment of Th17-related disorders. In this study, we found that eriodictyol (EDT), a natural flavonoid abundant in citrus fruits and peanuts, was located directly in the binding pocket of RORγt, and induced a conformational change that resulted in the effective suppression of the receptor's activity, thus offering insight into the transcriptional inhibition of RORγt-dependent genes. Consistent with this, EDT dose-dependently (5-10 μM) blocked murine Th17 differentiation, and markedly reduced IL-17A secretion in vitro. Furthermore, this compound has been found to have novel properties for directly inhibiting Th1 cell development and promoting Treg cell differentiation at high doses (≥10 μM). EDT administration significantly decreased the clinical severity in the EAE model, with inhibited demyelination and reduced inflammatory responses in the periphery and in the central nervous system (CNS). In the adoptive transfer model, EDT also remarkably suppressed the Th17 cell infiltration and pathogenicity. Collectively, our data demonstrated that EDT, as an agent for the pharmacological inhibition of RORγt, has great potential for immunomodulation, and for use in the treatment of Th17-mediated autoimmune disease.

Eriocalyxin B Inhibits Adipogenesis in 3T3-L1 Adipocytes by Cell Cycle Arrest

Eriocalyxin B, an ent-Kaurene diterpenoid extracted from a traditional Chinese herb Isodon eriocalyx, has been shown to possess multifunctional activities such as anti-cancer and anti-inflammatory. However, the function and mechanism of the compound in adipocyte differentiation is still unknown. Here we reported that eriocalyxin B blunted adipogenesis remarkably by inhibiting the accumulation of lipid droplets, triglycerides and the expressions of adipogenesis-related factors, including C/EBPβ, C/EBPα, PPARγ, and FABP4. Moreover, we showed that the inhibition might be the consequence of cell cycle being arrested at the G2/M phase during the mitotic clonal expansion of adipocyte differentiation, most likely by suppressing mRNAs and proteins of CDK1, CDK2, Cyclin A and Cyclin B1. Overall, we conclude that eriocalyxin B is capable of inhibiting adipocyte differentiation at the early stage through downregulating the proteins involved in cell cycle progression.

Tanshinone IIA Ameliorates CNS Autoimmunity by Promoting the Differentiation of Regulatory T Cells

Tanshinone IIA (TSA), an important natural lipophilic diterpene compound from the traditional Chinese herb Salvia miltiorrhiza Bunge, has long been widely used for the prevention and treatment of various diseases because of its anti-inflammatory activities; however, the anti-inflammatory mechanism remains unknown. In the present work, we examined the effects of TSA on experimental autoimmune encephalomyelitis (EAE), a model of autoreactive T/B cell-mediated central nervous system (CNS) autoimmunity. The data showed that TSA significantly attenuates the severity of EAE when administered at the pre-onset and peak of clinical disease. In vivo, the protective effects of TSA on EAE mice are correlated with diminished inflammatory infiltration, demyelination, and GM-CSF-producing CD4+ T cells in the spinal cord and selectively increased regulatory T (Treg) cell frequencies in both the spinal cord and spleen. We further confirm that TSA can promote the polarization of naïve CD4+ T cells into Treg cells both by targeting dendritic cells (DCs) to drive transforming growth factor β1 (TGF-β1) upregulation and by directly targeting naïve CD4+ T cells in vitro. Most importantly, we showed that TSA-induced Treg cells display an effective suppressive activity at a level comparable to TGF-β1-polarized Treg Cells in vitro and in vivo. Taken together, our data provide evidence that TSA can promote Treg cell differentiation, and TSA may have a promising application as a therapeutic agent for the treatment of neuroinflammatory diseases.

Two new 7, 20-epoxy-ent-kauranes from the aerial parts of Isodon eriocalyx

Two previously undescribed 7, 20-epoxy-ent-kauranes along with six known ent-kauranoids, were isolated from the aerial parts of Isodon eriocalyx. The structures of new compounds were established on the basis of extensive spectroscopic analyses. Compound 2 could inhibit the production of interleukin - 1β (IL - 1β) in monosodium urate (MSU) and lipopolysaccharide (LPS) induced macrophages.

Exosome derived from CD137-modified endothelial cells regulates the Th17 responses in atherosclerosis

The role of exosomes derived from endothelial cells (ECs) in the progression of atherosclerosis (AS) and inflammation remains largely unexplored. We aimed to investigate whether exosome derived from CD137‐modified ECs (CD137‐Exo) played a major role in AS and to elucidate the potential mechanism underlying the inflammatory effect. Exosomes derived from mouse brain microvascular ECs treated with agonist anti‐CD137 antibody were used to explore the effect of CD137 signalling in AS and inflammation in vitro and vivo. CD137‐Exo efficiently induced the progression of AS in ApoE^−/− mice. CD137‐Exo increased the proportion of Th17 cells both in vitro and vivo. The IL‐6 contained in CD137‐Exo which is regulated by Akt and NF‐КB pathway was verified to activate Th17 cell differentiation. IL‐17 increased apoptosis, inhibited cell viability and improved lactate dehydrogenase (LDH) release in ECs subjected to inflammation induced by lipopolysaccharide (LPS). The expression of soluble intercellular adhesion molecule1 (sICAM‐1), monocyte chemoattractant protein‐1 (MCP‐1) and E‐selectin in the supernatants of ECs after IL‐17 treatment was dramatically increased. CD137‐Exo promoted the progression of AS and Th17 cell differentiation via NF‐КB pathway mediated IL‐6 expression. This finding provided a potential method to prevent local and peripheral inflammation in AS.

Microglial Phenotypes and Their Relationship to the Cannabinoid System: Therapeutic Implications for Parkinson's Disease

Parkinson’s disease is a neurodegenerative disorder, the motor symptoms of which are associated classically with Lewy body formation and nigrostriatal degeneration. Neuroinflammation has been implicated in the progression of this disease, by which microglia become chronically activated in response to α-synuclein pathology and dying neurons, thereby acquiring dishomeostatic phenotypes that are cytotoxic and can cause further neuronal death. Microglia have a functional endocannabinoid signaling system, expressing the cannabinoid receptors in addition to being capable of synthesizing and degrading endocannabinoids. Alterations in the cannabinoid system—particularly an upregulation in the immunomodulatory CB₂ receptor—have been demonstrated to be related to the microglial activation state and hence the microglial phenotype. This paper will review studies that examine the relationship between the cannabinoid system and microglial activation, and how this association could be manipulated for therapeutic benefit in Parkinson’s disease.

Eriocalyxin B Biological Activity: A Review on Its Mechanism of Action

Natural products, a rich source of bioactive chemical compounds, have served humans as a safer drug of choice since times. Eriocalyxin B, an ent-Kaurene diterpenoid, has been extracted from a traditional Chinese herb Isodon eriocalyx. Experimental data support the anticancer and anti-inflammatory activities of EriB. This natural entity exhibits anticancer effects against breast, pancreatic, leukemia, ovarian, lung, bladder, and colorectal cancer. EriB has capability to inhibit the proliferation of cancer cells by prompting apoptosis, arresting cell cycle, and modulating cell signaling pathways. The regulation of signaling pathways in cancerous cells by EriB involves the modulation of various apoptosis-related factors (Bak, Bax, caspases, XIAP, survivin, and Beclin-1), transcriptional factors (nuclear factor kappa B [NF-κB], STAT3, Janus-activated kinase 2, Notch, AP-1, and lκBα), enzymes (cyclooxygenase 2, matrix metalloproteinase 2 [MMP-2], MMP-9, and poly (ADP-ribose) polymerase), cytokines, and protein kinases (mitogen-activated protein kinase and ERK1/2). This review proposes that EriB supplies a novel opportunity for the cure of cancer but supplementary investigations along with preclinical trials are obligatory to effectively figure out its biological and pharmacological applications.

Scopoletin Suppresses Activation of Dendritic Cells and Pathogenesis of Experimental Autoimmune Encephalomyelitis by Inhibiting NF-κB Signaling

Scopoletin, a phenolic coumarin derived from many medical or edible plants, is involved in various pharmacological functions. In the present study, we showed that Scopoletin effectively ameliorated experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), through novel regulatory mechanisms involving inhibition of NF-κB activity in dendritic cells (DCs). Scopoletin treatment significantly improved the severity of the disease and prominently decreased inflammation and demyelination of central nervous system (CNS) in EAE mice. Disease alleviation correlated with the downregulation of major histocompatibility complex (MHC) class II, CD80 and CD86, expressed on DCs of CNS or spleens, and the infiltration and polarization of encephalitogenic Th1/Th17 cells. Consistent with the in vivo data, Scopoletin-treated, bone marrow-derived dendritic cells (BM-DCs) exhibited reduced expression of MHC class II and costimulatory molecules (e.g., CD80 and CD86) and reduced NF-κB phosphorylation. These findings, for the first time, demonstrated the ability of Scopoletin to impair DC activation, downregulating pathogenic Th1/Th17 inflammatory cell responses and, eventually, reducing EAE severity. Our study demonstrates new evidence that natural products derived from medical or edible plants, such as Scopoletin, will be valuable in developing a novel therapeutic agent for MS in the future.

Flexicaulin A, An ent-Kaurane Diterpenoid, Activates p21 and Inhibits the Proliferation of Colorectal Carcinoma Cells through a Non-Apoptotic Mechanism

Natural products, explicitly medicinal plants, are an important source of inspiration of antitumor drugs, because they contain astounding amounts of small molecules that possess diversifying chemical entities. For instance, Isodon (formerly Rabdosia), a genus of the Lamiaceae (formerly Labiatae) family, has been reported as a rich source of natural diterpenes. In the current study, we evaluated the in vitro anti-proliferative property of flexicaulin A (FA), an Isodon diterpenoid with an ent-kaurane structure, in human carcinoma cells, by means of cell viability assay, flow cytometric assessment, quantitative polymerase chain reaction array, Western blotting analysis, and staining experiments. Subsequently, we validated the in vivo antitumor efficacy of FA in a xenograft mouse model of colorectal carcinoma. From our experimental results, FA appears to be a potent antitumor molecule, since it significantly attenuated the proliferation of human colorectal carcinoma cells in vitro and restricted the growth of corresponsive xenograft tumors in vivo without causing any adverse effects. Regarding its molecular mechanism, FA considerably elevated the expression level of p21 and induced cell cycle arrest in the human colorectal carcinoma cells. While executing a non-apoptotic mechanism, we believe the antitumor potential of FA opens up new horizons for the therapy of colorectal malignancy.

Diterpene synthases facilitating production of the kaurane skeleton of eriocalyxin B in the medicinal plant Isodon eriocalyx

The Isodon plants (Lamiaceae) have been used in traditional Chinese medicine to alleviate sufferings from inflammations and cancers. This feature has been attributed to the presence of pharmacologically active ent-kaurane diterpenoids such as eriocalyxin B and oridonin. The Isodon eriocalyx (Dunn) Kudô species native to southwest China can accumulate a particularly high content of ent-kaurane diterpenoids (∼1.5% w/w of dried leaves). We previously identified diterpene synthases IeCPS1 and IeCPS2 as ent-copalyl diphosphate synthases (ent-CPS) potentially involved in Isodon ent-kaurane diterpenoids biosynthesis. In this study, analysis of RNA-seq transcriptome of the I. eriocalyx plant revealed three other diterpene synthase genes (IeCPS3, IeKS1, and IeKSL1). Their functional characterization through coupled in vitro enzyme assays has confirmed that IeCPS3 is an ent-CPS specifically producing ent-copalyl diphosphate (ent-CPP). IeKS1 accepted ent-CPP to produce exclusively ent-kaurene and may thus be defined as an ent-kaurene synthase (ent-KS). When IeKSL1 was combined with IeCPS2 or IeCPS3, no product was detected. Based on tissue-specific expression and metabolic localization studies, the IeCPS3 and IeKS1 transcripts were significantly accumulated in leaves where the ent-kaurane diterpenoid eriocalyxin B dominates, whereas weak expression of both were observed in germinating seeds in which gibberellin biosynthetic pathway is normally active. Our findings suggest that both IeCPS3 and IeKS1 possess dual roles in general (gibberellins) and specialized diterpenoid metabolism, such as that of the Isodon ent-kaurane diterpenoids.

Maoeriocalysins A–D, four novelent-kaurane diterpenoids fromIsodon eriocalyxand their structure determination utilizing quantum chemical calculation in conjunction with quantitative interproton distance analysis

Maoeriocalysin A, an unprecedented 4,5-seco-3,5-cyclo-7,20-epoxy-ent-kauranoid, together with three rare 9,10-seco-ent-kauranoids, maoeriocalysins B–D, were isolated.

EriB targeted inhibition of microglia activity attenuates MPP+ induced DA neuron injury through the NF-κB signaling pathway

Accumulating evidence indicates that microglia activation is associated with an increased risk for developing Parkinson’s disease (PD). With the progressive and selective degeneration of dopaminergic (DA) neurons, proinflammatory cytokines are elevated in the substantia nigra (SN) of PD patients. Thus, anti-inflammation has become one of the therapeutic strategies of PD. Eriocalyxin B (EriB), a diterpenoid isolated from Isodoneriocalyx, was previously reported to have anti-inflammatory effects. MPTP mouse model and MPP⁺ cell model were prepared to detect the role of EriB in regulating microglia activation and neuron protection. Midbrain tissue and primary cultured microglia and neuron were used to examine microglia activation and neuron damage by immunofluorescence, real-time PCR, western-blot and Elisa assay. Open field activity test was to evaluate the changes of behavioral activity in MPTP-induced PD mouse model. EriB was efficacious in protecting DA neurons by inhibiting microglia activation in PD mice model. Treatment with EriB led to amelioration of disordered sports of PD mice model, which correlated with reduced microglia-associated inflammation and damaged DA neurons. EriB treatment abolished MPP⁺ induced microglia activation damages to DA neurons in a microglia and DA neurons co-culture system. The underlying mechanism of EriB-induced protective effects involved inhibition of microglia associated proinflammatory cytokines production through the phenotypic shift of microglial cells as well as activator of transcription and nuclear factor-κB (NF-κB) signaling pathways. These findings demonstrate that EriB exerts potent anti-inflammatory effects through selective modulation of microglia activation by targeting NF-κB signaling pathways, thus exerting the protective effect against on MPP⁺-induced DA neurons injury. This study may provide insights into the promising therapeutic role of EriB for PD.

A polysaccharide from Eclipta prostrata alleviates experimental autoimmune encephalomyelitis through inhibiting Th17 cells

Eclipta prostrata has long been used as a medicinal herb in China. EAP20-1, a homogeneous polysaccharide with anti-complementary activity had been obtained from E. prostrate by using anion-exchange and size-exclusion chromatography. In this study, we found that EAP20-1 could inhibit in vitro lymphocyte proliferation stimulated by concanavalin-A or anti-CD3/anti-CD28 antibodies. Furthermore, in experimental autoimmune encephalomyelitis (EAE) mice, EAP20-1 treatment relieved the clinical symptoms, accompanied by reduced neuroinflammation and demyelination in spinal cords. Mechanistically, EAP20-1 reduced the mRNA expression of interleukin (IL)-17, IL-22, and RAR-related orphan receptor gamma t (RORγt) in the spleen; inhibited auto-reactive T cell proliferation and decreased the percentage of Th17 cells in response to myelin oligodendrocyte glycoprotein (MOG35-55) ex vivo. Moreover, EAP20-1 directly inhibited naïve CD4 + T cells differentiate into Th17 cells in vitro. These results indicating EAP20-1 could benefit EAE through inhibiting Th17 cell differentiation and suggesting a therapeutic potential of EAP20-1 in MS.

Comparative transcriptome analysis of roots, stems and leaves of Isodon amethystoides reveals candidate genes involved in Wangzaozins biosynthesis

BACKGROUND

Isodon amethystoides (Ben-th) Cy Wu et Hsuan is an important traditional medicinal plant endowed with pharmacological properties effective in the treatment of various diseases, including pulmonary tuberculosis. The tetracyclic diterpenoids, Wangzaozins (Wangzaozin A, glaucocalyxin A, glaucocalyxin B), are the major bioactive compounds of I. amethystoides. However, the molecular information about the biosynthesis of these compounds still remains unclear.

RESULTS

An examination of the accumulated levels of Wangzaozins in I. amethystoides revealed considerable variations in the root, stem, and leaf tissues of this plant, indicating possible differences in metabolite biosynthesis and accumulation among various tissues. To better elucidate the tetracyclic diterpenoid biosynthesis pathway, we generated transcriptome sequences from the root, stem, and leaf tissues, and performed de novo sequence assembly, yielding 230,974 transcripts and 114,488 unigenes, with average N50 lengths of 1914 and 1241 bp, respectively. Putative functions could be assigned to 73,693 transcripts (31.9%) based on BLAST searches against annotation databases, including GO, KEGG, Swiss-Prot, NR, and Pfam. Moreover, the candidate genes involving in the diterpenoid biosynthesis, such as CPS, KSL, were also analyzed. The expression profiles of eight transcripts, involving the tetracyclic diterpenoid biosynthesis, were validated in different I. amethystoides tissues by qRT-PCR, unraveling the gene expression profile of the pathway. The differential expressions of ISPD, ISPF and ISPH (MEP pathway), and IaCPS and IaKSL (diterpenoid pathway) candidate genes in leaves and roots, may contribute to the high accumulation of Wangzaozins in I. amethystoides leaves.

CONCLUSION

The genomic dataset and analyses reported here lay the foundations for further research on this important medicinal plant.

The flavonoid kurarinone inhibits clinical progression of EAE through inhibiting Th1 and Th17 cell differentiation and proliferation

INTRODUCTION

The flavonoid kurarinone suppresses CD4+ T-cell-mediated chronic inflammatory dermatitis. However, kurarinone's effects upon autoimmune central nervous system (CNS) disease remain unknown. We investigated the potential therapeutic effects and molecular mechanism(s) of kurarinone in an experimental autoimmune encephalomyelitis (EAE) murine model of multiple sclerosis (MS).

MATERIALS AND METHODS

Myelin oligodendrocyte glycoprotein (MOG_35-55) peptide-induced EAE was constructed in wild-type mice. Effects of kurarinone (100 mg/kg/day) upon clinical scores were assessed based on physical traits and signs. Spinal cord sections were extracted to assess inflammation, demyelination, and mRNA expression of key pro-inflammatory cytokines and chemokines. CNS-infiltrating mononuclear cells (MNCs) and splenocytes were harvested; flow cytometry was then applied to determine CD4+ and CD8+ T-cell percentages as well as Th1/Th2/Th17 subset percentages. Purified naïve CD4+ T-cells underwent in vitro T-cell polarization and proliferation to assess kurarinone's effects.

RESULTS

Prophylactic and treatment regimens of kurarinone significantly improved clinical scores in the MOG_35-55 peptide-induced EAE model (P < 0.05). Kurarinone significantly lowered CNS inflammation and demyelination (61% and 83% decreases, respectively; P < 0.05), significantly decreased MNC infiltration into CNS tissue (42% decrease; P < 0.05), and significantly inhibited levels of several pro-inflammatory cytokines and chemokines (P < 0.05). Kurarinone significantly lowered CD4+ and CD8+ CNS T-cell counts (51% and 80% decreases, respectively; P < 0.05) and significantly reduced CNS Th1 and Th17 cell percentages (24% and 44% decreases, respectively; P < 0.05). Kurarinone significantly inhibited in vitro Th1, Th2, and Th17 cell differentiation and proliferation (P < 0.05).

CONCLUSIONS

Kurarinone significantly inhibits the clinical progression of EAE through the inhibition of Th1 and Th17 cell differentiation and proliferation. Kurarinone may show promise as an immunomodulatory therapeutic agent in treating MS.

Glycyrrhizin Protects Mice Against Experimental Autoimmune Encephalomyelitis by Inhibiting High-Mobility Group Box 1 (HMGB1) Expression and Neuronal HMGB1 Release

The inflammatory mediator high-mobility group box 1 (HMGB1) plays a critical role in the pathogenesis of human multiple sclerosis (MS) and mouse experimental autoimmune encephalomyelitis (EAE). Glycyrrhizin (GL), a glycoconjugated triterpene extracted from licorice root, has the ability to inhibit the functions of HMGB1; however, GL’s function against EAE has not been thoroughly characterized to date. To determine the benefit of GL as a modulator of neuroinflammation, we used an in vivo study to examine GL’s effect on EAE along with primary cultured cortical neurons to study the GL effect on HMGB1 release. Treatment of EAE mice with GL from onset to the peak stage of disease resulted in marked attenuation of EAE severity, reduced inflammatory cell infiltration and demyelination, decreased tumor necrosis factor-alpha (TNF-α), IFN-γ, IL-17A, IL-6, and transforming growth factor-beta 1, and increased IL-4 both in serum and spinal cord homogenate. Moreover, HMGB1 levels in different body fluids were reduced, accompanied by a decrease in neuronal damage, activated astrocytes and microglia, as well as HMGB1-positive astrocytes and microglia. GL significantly reversed HMGB1 release into the medium induced by TNF-α stimulation in primary cultured cortical neurons. Taken together, the results indicate that GL has a strong neuroprotective effect on EAE mice by reducing HMGB1 expression and release and thus can be used to treat central nervous system inflammatory diseases, such as MS.

Isolation, evaluation of bioactivity and structure determination of amethinol A, a prototypic amethane diterpene from Isodon amethystoides bearing a six/five/seven-membered carbon-ring system

We report the isolation of a novel diterpene, designated as `amethane', from Isodon amethystoides (Lamiaceae). The diterpene [amethinol A; systematic name: (4aR,4bR,7R,10aS)-4b,7-dihydroxy-7-isopropyl-1,1-dimethyl-9-oxododecahydrobenzo[a]azulene-4a(2H)-carboxylic acid], possesses a unique skeleton containing a six/five/seven-membered tricyclic system. Intermolecular O-H...O close contacts were found to the carboxyl, carbonyl and hydroxy groups, connecting molecules into a two-dimensional structure. A possible biosynthetic pathway has been proposed. In addition, the compound was evaluated for its biological activities against different disease targets, and was found to significantly attenuate RORγt-dependent autoimmune responses.

Eriocalyxin B, a natural diterpenoid, inhibited VEGF-induced angiogenesis and diminished angiogenesis-dependent breast tumor growth by suppressing VEGFR-2 signaling

Eriocalyxin B (EriB), a natural ent-kaurane diterpenoid isolated from the plant Isodon eriocalyx var. laxiflora, has emerged as a promising anticancer agent. The effects of EriB on angiogenesis were explored in the present study. Here we demonstrated that the subintestinal vein formation was significantly inhibited by EriB treatment (10, 15 μM) in zebrafish embryos, which was resulted from the alteration of various angiogenic genes as shown in transcriptome profiling. In human umbilical vein endothelial cells, EriB treatment (50, 100 nM) could significantly block vascular endothelial growth factors (VEGF)-induced cell proliferation, tube formation, cell migration and cell invasion. Furthermore, EriB also caused G1 phase cell cycle arrest which was correlated with the down-regulation of the cyclin D1 and CDK4 leading to the inhibition of phosphorylated retinoblastoma protein expression. Investigation of the signal transduction revealed that EriB inhibited VEGF-induced phosphorylation of VEGF receptor-2 via the interaction with the ATP-binding sites according to the molecular docking simulations. The suppression of VEGFR-2 downstream signal transduction cascades was also observed. EriB was showed to inhibit new blood vessel formation in Matrigel plug model and mouse 4T1 breast tumor model. EriB (5 mg/kg/day) treatment was able to decrease tumor vascularization and suppress tumor growth and angiogenesis. Taken together, our findings suggested that EriB is a novel inhibitor of angiogenesis through modulating VEGFR-2 signaling pathway, which could be developed as a promising anti-angiogenic agent for treatment of angiogenesis-related human diseases, such as cancer.

Diterpenoids from Isodon species: an update

Covering: December 2005 to June 2016. Previous review: Nat. Prod. Rep., 2006, 23, 673-698Over the last decade, great efforts have been made to conduct phytochemistry research on the genus Isodon, which have led to the isolation and identification of a number of diterpenoids. At the same time, these newly reported diterpenoids with diverse structures have led to new findings on their biological functions and chemical synthesis research. In this update, we review more than 600 new diterpenoids, including their structures, classifications, biogenetic pathways, bioactivities, and chemical synthesis.

IL-17-triggered downregulation of miR-497 results in high HIF-1α expression and consequent IL-1β and IL-6 production by astrocytes in EAE mice

Interleukin 17 (IL-17) is increasingly recognized as a key factor that contributes to the pathogenesis of multiple sclerosis (MS) and its experimental mouse autoimmune encephalomyelitis (EAE) model. However, the roles and regulatory mechanisms of IL-17-induced pro-inflammatory cytokine production in EAE mice remain largely unclear. In this study, the expression of IL-17, hypoxia inducible factor-1α (HIF-1α), IL-1β, IL-6 and microRNA-497 (miR-497), as well as their intrinsic associations, was investigated using EAE model mice and cultured astrocytes exposed to IL-17 in vitro. We observed markedly increased production of IL-17, HIF-1α, IL-1β and IL-6 in the brain tissues of EAE mice, while the expression and secretion of HIF-1α, IL-1β and IL-6 were also significantly increased when cultured primary astrocytes from mice were stimulated with IL-17. Meanwhile, the expression of miR-497 was downregulated both in vivo and in vitro. Subsequent in vitro experiments revealed that IL-17 induced the production of IL-1β and IL-6 in astrocytes through the upregulation of HIF-1α as a transcriptional factor, indicating that IL-17-mediated downregulation of miR-497 enhanced HIF-1α expression. Furthermore, astrocyte-specific knockdown of IL-17RA and HIF-1α or astrocyte-specific overexpression of miR-497 by infection with different lentiviral vectors containing an astrocyte-specific promotor markedly decreased IL-1β and IL-6 production in brain tissues and alleviated the pathological changes and score of EAE mice. Collectively, these findings indicate that decreased miR-497 expression is responsible for IL-17-triggered high HIF-1α expression and consequent IL-1β and IL-6 production by astrocytes in EAE mice.Cellular & Molecular Immunology advance online publication, 1 May 2017; doi:10.1038/cmi.2017.12.

Suppression of Th17 cell differentiation by misshapen/NIK-related kinase MINK1

T helper type 17 cells (Th17 cells) are major contributors to many autoimmune diseases. In this study, we demonstrate that the germinal center kinase family member MINK1 (misshapen/NIK-related kinase 1) negatively regulates Th17 cell differentiation. The suppressive effect of MINK1 on induction of Th17 cells is mediated by the inhibition of SMAD2 activation through direct phosphorylation of SMAD2 at the T324 residue. The importance of MINK1 to Th17 cell differentiation was strengthened in the animal model of experimental autoimmune encephalomyelitis (EAE). Moreover, we show that the reactive oxygen species (ROS) scavenger N-acetyl cysteine boosts Th17 cell differentiation in a MINK1-dependent manner and exacerbates the severity of EAE. Thus, we have not only established MINK1 as a critical regulator of Th17 cell differentiation, but also clarified that accumulation of ROS may limit the generation of Th17 cells. The contribution of MINK1 to ROS-regulated Th17 cell differentiation may suggest an important mechanism for the development of autoimmune diseases influenced by antioxidant dietary supplements.

Efficient Semisynthesis of (-)-Pseudoirroratin A from (-)-Flexicaulin A and Assessment of Their Antitumor Activities

Accumulating evidence indicates that natural ent-kaurane diterpenoids show great potential for medical treatment of different pathological conditions including cytotoxicity, antibacterial, and anti-inflammatory activity. Among a variety of diterpenoids tested, (-)-pseudoirroratin A displayed a promising antitumor property in vitro and in vivo. However, this diterpenoid could merely be isolated in a limited amount from a rare source of Isodon pseudoirrorata. To overcome such scanty source, we developed a novel, facile, and efficient semisynthetic strategy to prepare (-)-pseudoirroratin A from natural (-)-flexicaulin A, which can be expediently obtained from I. flexicaulis in a great quantity. The three-dimensional structure and the absolute configuration of our synthetic diterpenoid have been determined and confirmed with the X-ray crystallographic analysis. More importantly, we demonstrated for the first time that pseudoirroratin A exerted significant cytotoxicity against human colorectal carcinoma cells via an induction of apoptosis, as well as a remarkable suppression on tumor growth in a colon cancer xenograft mouse model.

Deciphering chemical interactions between Glycyrrhizae Radix and Coptidis Rhizoma by liquid chromatography with transformed multiple reaction monitoring mass spectrometry

In this study, we propose an integrated strategy for the efficient identification and quantification of herbal constituents using liquid chromatography with mass spectrometry. First, liquid chromatography with quadrupole time-of-flight mass spectrometry was employed for the chemical profiling of herbs, where a targeted following nontargeted approach was developed to detect trace constituents by using structural correlations and extracted ion chromatograms. Next, ion pairs and parameters of MS² of quadrupole time-of-flight mass spectrometry were selected to design multiple reaction monitoring transitions for the identified compounds on liquid chromatography with triple quadrupole mass spectrometry. The relative concentration of each constituent was then calculated using a semiquantitative calibration curve. The proposed strategy was applied in a study of chemical interactions between Glycyrrhizae Radix and Coptidis Rhizoma. A total of 140 compounds were identified or tentatively characterized from the herbs, 132 of which were relatively quantified. The visualized quantitative results clearly showed codecoction produced significant constituent concentration variations especially for those with a low polarity. The case study also indicated that the present methodology could provide a reliable, accurate, and labor-saving solution for chemical studies of herbal medicines.

Paeoniflorin Ameliorates Experimental Autoimmune Encephalomyelitis via Inhibition of Dendritic Cell Function and Th17 Cell Differentiation

Paeoniflorin (PF) is a monoterpene glycoside and exhibits multiple effects, including anti-inflammation and immunoregulation. To date, the effect of PF on multiple sclerosis (MS) has not been investigated. In this study, we investigated the effect of PF in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. After administered with PF, the onset and clinical symptoms of EAE mice were significantly ameliorated, and the number of Th17 cells infiltrated in central nervous system (CNS) and spleen was also dramatically decreased. Instead of inhibiting the differentiation of Th17 cells directly, PF influenced Th17 cells via suppressing the expression of costimulatory molecules and the production of interlukin-6 (IL-6) of dendritic cells (DCs) in vivo and in vitro, which may be attributable to the inhibition of IKK/NF-κB and JNK signaling pathway. When naïve CD4⁺ T cells were co-cultured with PF-treated dendritic cells under Th17-polarizing condition, the percentage of Th17 cells and the phosphorylation of STAT3 were decreased, as well as the mRNA levels of IL-17, RORα, and RORγt. Our study provided insights into the role of PF as a unique therapeutic agent for the treatment of multiple sclerosis and illustrated the underlying mechanism of PF from a new perspective.

Epieriocalyxin A Induces Cell Apoptosis Through JNK and ERK1/2 Signaling Pathways in Colon Cancer Cells

Colorectal cancer is one of the most commonly diagnosed cancers in the world. Currently, drug resistance of cancer cell to chemotherapy is a major cause for cancer recurrence and death of the patients; therefore, new therapeutic strategy is required to improve the care of colorectal cancer patients. The Chinese herb, Isodon eriocalyx, has been used a therapeutic for a long time in China. In this study, we showed that Epieriocalyxin A (EpiA), a diterpenoid isolated from I. eriocalyx, suppressed Caco-2 colon cancer cell growth. EpiA induced annexin V flipping in cell membrane and DNA fragment. We also showed that EpiA induced the generation of ROS in cells, as well as damage of the mitochondrial membrane. Western blot results showed that both JNK and ERK1/2 activation was decreased after EpiA treatment in a dose-dependent manner. EpiA increased the expression of caspase 3 and Bax, and decreased Bcl2 expression. Our results suggest that EpiA is a novel compound that induces colon cancer apoptosis. EpiA could be a potential drug for colon cancer therapy in the future.

BJ-3105, a 6-Alkoxypyridin-3-ol Analog, Impairs T Cell Differentiation and Prevents Experimental Autoimmune Encephalomyelitis Disease Progression

CD4⁺ T cells are essential in inflammation and autoimmune diseases. Interferon-γ (IFN-γ) secreting T helper (Th1) and IL-17 secreting T helper (Th17) cells are critical for several autoimmune diseases. To assess the inhibitory effect of a given compound on autoimmune disease, we screened many compounds with an in vitro Th differentiation assay. BJ-3105, a 6-alkoxypyridin-3-ol analog, inhibited IFN-γ and IL-17 production from polyclonal CD4⁺ T cells and ovalbumin (OVA)-specific CD4⁺ T cells which were activated by T cell receptor (TCR) engagement. BJ-3105 ameliorated the experimental autoimmune encephalomyelitis (EAE) model by reducing Th1 and Th17 generation. Notably, Th cell differentiation was significantly suppressed by BJ-3105 treatment without inhibiting in vitro proliferation of T cells or inducing programmed cell death. Mechanistically, BJ-3105 inhibited the phosphorylation of JAK and its downstream signal transducer and activator of transcription (STAT) that is critical for Th differentiation. These results demonstrated that BJ-3105 inhibits the phosphorylation of STAT in response to cytokine signals and subsequently suppressed the differentiation of Th cell responses.

Amelioration of Experimental Autoimmune Encephalomyelitis by Isogarcinol Extracted from Garcinia mangostana L. Mangosteen

Isogarcinol is a new natural immunosuppressant that was extracted from Garcinia mangostana L. in our laboratory. Knowledge of its effects on treatable diseases and its mechanism of action is still very limited. In this study, we explored the therapeutic effect of isogarcinol in experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). Treatment with oral 100 mg/kg isogarcinol markedly ameliorated clinical scores, alleviated inflammation and demyelination of the spinal cord, and reduced intracranial lesions in EAE mice. The percentages of Th cells and macrophages were also strongly reduced. Isogarcinol appeared to act by inhibiting T helper (Th) 1 and Th17 cell differentiation via the janus kinase/signal transducers and activators of transcription pathway and by impairing macrophage function. Our data suggest that isogarcinol has the potential to be an effective therapeutic agent of low toxicity for treating MS and other autoimmune diseases.

A novel human truncated IL12rβ1-Fc fusion protein ameliorates experimental autoimmune encephalomyelitis via specific binding of p40 to inhibit Th1 and Th17 cell differentiation

Interleukin (IL)-12 and IL-23 respectively driving polarization of T helper (Th) 1 and Th17 cells has been strongly implicated in the pathogenesis of both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). In this study, we first constructed, expressed and purified a novel human truncated IL12rβ1-Fc fusion protein (tIL12rβ1/Fc) binding multiple forms of the p40 subunit of human IL-12 and IL-23. tIL12rβ1/Fc was found to effectively ameliorate MOG_35–55-induced EAE through reducing the production of Th1- and Th17-polarized pro-inflammatory cytokines and suppressing inflammation and demyelination in the focused parts. Moreover, tIL12rβ1/Fc suppressed Th1 (IFN-γ⁺ alone) and IFN-γ⁺ IL-17⁺ as well as the population of classic Th17 (IL-17⁺ alone) cells in vivo. Furthermore, tIL12rβ1/Fc ameliorated EAE at the peak of disease via the inhibition of STAT pathway, thereby causing a prominent reduction of RORγt (Th17) and T-bet (Th1) expression. Notably, tIL12rβ1/Fc could increase the relative number of CD4⁺ Foxp3⁺ regulatory T cells. These findings indicates that tIL12rβ1/Fc is a novel fusion protein for specific binding multiple forms of p40 subunit to exert potent anti-inflammatory effects and provides a valuable approach for the treatment of MS and other autoimmune diseases.

Accumulation of reactivity to MBP sensitizes TRAIL mediated oligodendrocyte apoptosis in adult sub cortical white matter in a model for human multiple sclerosis

Reactivity to myelin associated proteins is the hallmark of human multiple sclerosis (M.S) and its experimental counterparts. However, the nature of such reactivity has not been described fully. Herein, we report that myelin basic protein (MBP) reactivity accumulates in a rat model for M.S. over a period of time and sensitizes TRAIL mediated progressive oligodendrocyte apoptosis. We used active immunization by Myelin Oligodendrocyte Glycoprotein (MOG, 50 μg) to study chronic remitting relapsing encephalomyelitis in rats. A time point analysis of the progressive disease revealed cumulative accumulation of anti myelin basic protein antibodies during the disease progression with minimal change in the anti-MOG antibodies. Increased reactivity to MBP was studied to sensitize TNF related apoptosis-inducing ligand (TRAIL) and other proinflammatory cytokines in a cumulative fashion leading to the Caspase dependent apoptosis of oligodendrocytes and myelin loss. In a rescue experiment, we could limit the demyelination and prevent disease progression by neutralizing the effector, TRAIL in an early stage of the disease. This is the first study to identify the accumulation of MBP antibodies in MOG induced EAE which possibly leads to TRAIL sensitized oligodendrocyte apoptosis in the white mater of EAE rats. This finding stresses on the need to study MBP antibody titers in M.S. patients and therefore might serve as an alternate marker for progressive demyelination.

Daphnetin Alleviates Experimental Autoimmune Encephalomyelitis via Regulating Dendritic Cell Activity

AIMS

Daphnetin, a coumarin derivative extracted from Daphne odora var. marginata, has been reported to have antiinflammatory and immunosuppressive properties. Our previous study indicated that it was able to remarkably suppress the neuroinflammation and suggested its potential application in treating neuroinflammatory diseases. Multiple sclerosis (MS), a Th cell-mediated autoimmune disease, is the most common inflammatory demyelinating disease of the central nervous system (CNS). We examined whether daphnetin treatment can protect mice against experimental autoimmune encephalomyelitis (EAE), an animal model for MS.

METHODS

To assess the effect of daphnetin in neuroinflammatory diseases, the EAE mice were established and treated with daphnetin at 8 mg/kg for 28 days. The severity of neuroinflammation and demyelination in the spinal cords was examined histopathologically. Infiltration of CD4(+) T cells into the CNS was assessed by immunohistochemistry, and the cytokine production was determined by ELISA. Meanwhile, the effect of daphnetin on the activity of dendritic cells (DCs) was evaluated, as assessed by DCs' capability to express surface markers, secrete cytokines, and activate naïve CD4(+) T cells. Furthermore, we explored the molecular mechanisms whereby DAPH regulated DCs' activity and thereby CD4(+) T cell responses.

RESULTS

The administration of daphnetin markedly alleviated the clinical symptoms of EAE and reduced the CNS inflammation and demyelination in experimental mice. Th1 and Th17 cell responses were profoundly repressed in daphnetin-treated EAE mice. Mechanistically, daphnetin treatment significantly repressed the activation, maturation, and antigen-presenting capability of DCs. NF-κB signaling was significantly reduced in daphnetin-treated DCs, along with a concomitant induction of heme oxygenase-1, a negative regulator of inflammatory signaling.

CONCLUSIONS

Our findings for the first time demonstrate the property of daphnetin in regulating DCs' function and subsequently Th development. Given the low or absent toxicity associated with daphnetin, our data may suggest a novel safe and effective approach to control autoimmune neuroinflammation.

Eriocalyxin B blocks human SW1116 colon cancer cell proliferation, migration, invasion, cell cycle progression and angiogenesis via the JAK2/STAT3 signaling pathway

Eriocalyxin B, a natural ent-kaurene diterpene compound, has been shown to prevent carcinogenesis and tumor development. However, little is known regarding the mechanism underlying the antitumor activity of Eriocalyxin B in human colon cancer. The aim of the present study was to examine the role of Eriocalyxin B in SW1116 cells, and to verify the hypothesis that the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway may serve as a therapeutic target in human colon cancer treatment. Cell proliferation was measured with a Cell Counting kit‑8 assay, and the cell cycle was assessed by flow cytometry. Cell migration and invasion were measured by Transwell analysis. In addition, western blot analysis was performed to detect the protein expression levels in SW1116 cells treated with various concentrations of Eriocalyxin B. The results demonstrated that 1 µmol/l Eriocalyxin B was effective at inhibiting JAK2 and STAT3 phosphorylation, followed by the downregulation of JAK2 and STAT3 downstream target expression, which resulted in the inhibition of cell proliferation, migration, invasion and angiogenesis. Eriocalyxin B also suppressed the expression of proliferation‑associated protein (proliferating cell nuclear antigen) and angiogenesis‑associated proteins (vascular endothelial growth factor and vascular endothelial growth factor receptor 2), as well as that of migration- and invasion‑associated proteins (matrix metalloproteinase 2 and 9). These results suggested that Eriocalyxin B may suppress JAK2/STAT3 signaling, and thus act as a therapeutic or preventive agent in the treatment of human colon cancer.