Immunosuppressant discovery from Tripterygium wilfordii Hook f: the novel triptolide analog (5R)-5-hydroxytriptolide (LLDT-8)

Potential antitumor activity of triptolide and its derivatives: Focused on gynecological and breast cancers

Cancer remains one of the greatest global health concerns. This is especially true for gynecological cancers, which include cervical, ovarian, and endometrial cancers, and breast cancer. Natural products used for cancer treatment offer some unique advantages. Triptolide (TPL) is a biologically active terpenoid extracted from Tripterygium wilfordii, which exhibits anti-inflammatory, immunosuppressive, antitumor, and other pharmacological activities. However, clinical applications of TPL are restricted because of poor water solubility and severe cytotoxicity; to overcome these limitations, various TPL derivatives and drug delivery systems, especially nanocarriers, have been used. Furthermore, various preclinical and clinical studies have demonstrated that TPL and its derivatives exhibit excellent antitumor effects by targeting proteins involved in multiple signaling pathways. Here, we review the progress regarding novel drug delivery systems, antitumor activities, and molecular mechanisms of action of TPL and its derivatives against gynecological and breast cancers. TPL and its derivatives inhibit tumor growth, suppress tumor metastasis, and enhance the drug sensitization of resistant cancers. In addition, TPL and its derivatives exert synergistic antitumor effects against gynecological and breast cancers when combined with existing antitumor drugs, such as carboplatin, cisplatin, and PI3K inhibitors. Moreover, we highlight the clinical potential of TPL analogs against cancer from bench to bedside and their prospects for future applications in gynecologic and breast cancers.

Mechanisms of Tripterygium wilfordii Hook F on treating rheumatoid arthritis explored by network pharmacology analysis and molecular docking

Background

Rheumatoid arthritis (RA) is a chronic inflammatory and disabling disease that imposes significant economic and social costs. Tripterygium wilfordii Hook F (TwHF) has a long history of use in traditional Chinese medicine for treating joint disorders, and it has been shown to be cost-effective in treating RA, but its exact mechanism is unknown.

Objective

The goal of the network pharmacology analysis and molecular docking was to investigate the potential active compounds and associated anti-RA mechanisms of TwHF.

Methods

TCMSP and UniProt databases were searched for active compounds and related targets of TwHF. PharmGKB, DrugBank, OMIM, TTD, and the Human Gene Databases were used to identify RA-related targets. The intersected RA and TwHF targets were entered into the STRING database to create a protein-protein interaction network. R software was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Molecular docking technology was used to analyze the optimal effective components from TwHF for docking with the selected target gene.

Results

Following screening and duplicate removal, a total of 51 active compounds and 96 potential targets were chosen. The PPI network revealed that the target proteins are CXCL8, CXCL6, STAT3, STAT1, JUN, PPARG, TP53, IL14, MMP9, VEGFA, RELA, CASP3, PTGS2, IFNG, AKT1, FOS, ICAM1, and MAPK14. The results of the GO enrichment analysis focused primarily on the response to lipopolysaccharide, the response to molecules of bacterial origin, and the response to drugs. The KEGG results indicated that the mechanisms were closely related to lipid and atherosclerosis, chemical carcinogenesis-receptor activation, Kaposi sarcoma-associated, herpesvirus infection, hepatitis B, fluid shear stress and atherosclerosis, IL-17 signaling pathways, Th17-cell differentiation, and so on, all of which are involved in angiogenesis, immune cell chemotaxis, and inflammatory responses. Molecular docking results suggested that triptolide was the appropriate PTGS1, PTGS2, and TNF inhibitors.

Conclusion

Our findings provide an essential role and basis for further immune inflammatory studies into the molecular mechanisms of TwHF and PTGS1, PTGS2, and TNF inhibitor development in RA.

Approaches, Strategies and Procedures for Identifying Anti-Inflammatory Drug Lead Molecules from Natural Products

Natural products (NPs) have played a vital role in human survival for millennia, particularly for their medicinal properties. Many traditional medicine practices continue to utilise crude plants and animal products for treating various diseases, including inflammation. In contrast, contemporary medicine focuses more on isolating drug-lead compounds from NPs to develop new and better treatment drugs for treating inflammatory disorders such as inflammatory bowel diseases. There is an ongoing search for new drug leads as there is still no cure for many inflammatory conditions. Various approaches and technologies are used in drug discoveries from NPs. This review comprehensively focuses on anti-inflammatory small molecules and describes the key strategies in identifying, extracting, fractionating and isolating small-molecule drug leads. This review also discusses the (i) most used approaches and recently available techniques, including artificial intelligence (AI), (ii) machine learning, and computational approaches in drug discovery; (iii) provides various animal models and cell lines used in in-vitro and in-vivo assessment of the anti-inflammatory potential of NPs.

Medicinal patterns of vines used in Chinese herbal medicine: a quantitative study

ETHNOPHARMACOLOGICAL RELEVANCE

The botanical characteristics of twinning, climbing vine plants conceptually take shape to interlink the meridians and collaterals system throughout the human body by expelling climatic evils (e.g., wind, dampness). Thus, vines have displayed great medicinal properties in traditional Chinese medicine (TCM).

AIM OF THE STUDY

Although some popular vine species have been intensively investigated, the comparable features and medicinal specifications among a vast collection of taxonomic groups based on data visualization methods are relatively lacking in attention. Moreover, the translatability of vines from ancient ethnomedical evidence to modern medical system has not been well established. This review tends to quantitatively summarize the strength of vines in healthcare from the perspectives of medicinal part, traditional function, clinical spectrum, phytochemistry divergence, pharmacological attributes, toxicity as well as the progress of proprietary drug development.

MATERIALS AND METHODS

Medicinal vines were retrieved from databases of drug standards and curated catalogues. Synonyms of plant origin across different datasets were normalized by accepted scientific names in the World Flora Online. The distribution patterns and rank of plant origin, medicinal parts, traditional functions and target conditions, as well as the correlation between phytochemical composition and clinical applications were analyzed and visualized.

RESULTS

A total of 121 crude drugs from 36 families, 77 genera, 133 species of vines were obtained and analyzed. The Fabaceae, Menispermaceae and Rubiaceae were the highest ranked families of medicinal vines. Not surprisingly, stem was the most dominant medical part. Moreover, "eliminate wind" displayed a hub node in the traditional function co-occurrence network. In addition to joint impediment disorders, these vines particularly displayed a wide range of therapeutic modalities toward conditions from various organ systems. Chemotaxonomic properties-oriented phytochemical analysis was performed and the chemical diversity among medicinal vines complementarily determined a certain group of therapeutic domains. Particularly, the anti-inflammatory effect and antiarthritic effect were highlighted for treating rheumatic diseases. Using integral animal models and cultured cells, modern pharmacological actions of medicinal vines have been largely observed and validated according to their traditional ethnopharmacology. Furthermore, a small proportion of vine species are well-known toxic plants. Successful drug development pipelines in rheumatic, cardiovascular, liver, malignant and infectious diseases have offered the capacity to generate new treatment options that are being sought out from vine plants.

CONCLUSIONS

Medicinal vines are rich sources of Chinese Material Medica (CMM) and good fit for a variety of clinical manifestations beyond arthritis and rheumatic diseases. In addition to stem, other parts are also popular for both medicines and dietary supplements. Vine plants provide extensive biologically relevant chemical space for developing value-creating drugs. Thus, our analysis can be useful for further motivating and strengthening the preclinical and clinical research of vine-derived remedies.

Comprehensive transcriptomic analyses identify the immunosuppressive effects of LLDT-8 in ART-treated SIV-infected rhesus macaques

BACKGROUND

Chronic immune activation plays a significant role in the pathogenesis and disease progression of human immunodeficiency virus (HIV), and the existing interventions to address this issue are limited. In a phase II clinical trial, (5R)-5-hydroxytriptolide (LLDT-8) demonstrated promising potential in enhancing CD4+ T cell recovery. However, the therapeutical effects of LLDT-8 remained to be systemic explored.

METHODS

To assess the treatment effects of LLDT-8, we conducted flow cytometry and RNA-seq analyses on eight Chinese rhesus monkeys infected with simian immunodeficiency virus (SIV). Additionally, we performed comprehensive transcriptomic analyses, including cross-sectional and longitudinal differentially expressed gene (DEG) analysis, gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution analysis using peripheral blood mononuclear cell (PBMC) samples from 14-time points. These findings were further validated with RNA-seq analysis on patients who received LLDT-8 treatment, along with in vitro cellular experiments using human PBMCs.

RESULTS

Flow cytometry analysis revealed that LLDT-8 treatment significantly reduced the percentage of HLA-DR+CD38+CD8+ T cells in SIV-infected rhesus monkeys (P < 0.001). The cross-sectional and longitudinal analysis identified 2531 and 1809 DEGs, respectively. GSEA analysis indicated that LLDT-8 treatment led to significant downregulation of proliferation-related pathways, such as E2F targets, G2M checkpoint, and mitotic spindle pathways. WGCNA analysis identified two modules and 202 hub genes associated with CD8 activation levels. Deconvolution analysis showed a significant decrease in the proportion of CD8+ T cells and activated CD4+ T cells during LLDT-8 treatment. Gene ontology results demonstrated that the common DEGs between LLDT-8-treated patients and rhesus monkeys were primarily enriched in cell activation and cell cycle progression. Furthermore, in vitro cellular experiments validated the consistent impact of LLDT-8 in inhibiting proliferation, activation (HLA-DR and CD38 expression), exhaustion (PD-1 expression), and IFN-γ production in human CD4+ and CD8+ T cells.

CONCLUSION

LLDT-8 exhibited notable efficacy in alleviating immune activation in both an in vivo animal model and in vitro human cell experiments. These findings suggest that LLDT-8 may hold potential as a drug for managing systemic immune activation associated with SIV/HIV infection, warranting further prospective clinical exploration.

LLDT-8 ameliorates experimental autoimmune encephalomyelitis by mediating macrophage functions in the priming stage

Multiple sclerosis (MS) is an inflammatory demyelinating disease in the central nervous system caused by T cell activation mediated by peripheral macrophages, resulting in severe neurological deficits and disability. Due to the currently limited and expensive treatments for MS, we here introduce an economic Chinese medicine extract, (5R)-5-Hydroxytriptolide (LLDT-8), which shows low toxicity and high immunosuppressive activity. We used the widely accepted mouse model of MS, experimental autoimmune encephalomyelitis (EAE), to examine the immunosuppressive effect of LLDT-8 in vivo. Through the RNA-sequence analysis of peripheral macrophages in EAE mice, we discovered that LLDT-8 alleviates the symptoms of EAE by inhibiting the proinflammatory effect of macrophages, thereby blocking the activation and proliferation of T cells. In all, we found that LLDT-8 could be a potential treatment for MS.

(5R)-5-hydroxytriptolide ameliorates diabetic kidney damage by inhibiting macrophage infiltration and its cross-talk with renal resident cells

OBJECTIVE

Diabetic nephropathy (DN) is the main cause of end-stage renal disease, and there are no targeted treatment options at present. The efficacy of the new immunosuppressive drug (5R)-5-hydroxytriptolide (LLDT8) in improving kidney inflammation has been demonstrated in multiple studies. The present study was intended to investigate the preventive and therapeutic effects of LLDT8 on DN and to reveal its potential pharmacological mechanisms.

METHODS

The effects of LLDT8 on liver and kidney functions, and urine microprotein of Streptozotocin (STZ) induced DN mice were detected. The protective effect of LLDT8 on the kidney tissue was observed by pathological staining and transmission electron microscopy. Cell culture experiments were performed to detect the effects of LLDT8 on the expression of chemokines and epithelial-mesenchymal transition (EMT) in high glucose-induced TCMK1 cells using real-time polymerase chain reaction (RT-PCR) and western blot (WB) techniques and to detect the influence of LLDT8 on the secretion of pro-inflammatory and pro-fibrotic factors in high glucose-induced RAW264.7 cells.

RESULTS

In animal experiments, treatment with high-dose LLDT8 (0.25 mg/kg/2d) reduced 24 h urinary albumin excretion, improved structural kidney damage, and delayed fibrosis progression in DN mice. Immunofluorescence results showed that LLDT8 intervention reduced macrophage infiltration in kidney tissues of DN mice. PCR and WB results of kidney tissues showed reduced expressions of chemokines CCL2 and M-CSF1 in the LLDT8 intervention group compared to the DN group. In cellular assays, LLDT8 treatment reduced chemokine secretion in high glucose-induced TCMK1 cells, but had no effect on EMT of TCMK1 cells. LLDT8 treatment reduced the secretion of pro-inflammatory and pro-fibrotic factors in high glucose-induced RAW264.7 cells.

CONCLUSIONS

The present study suggests that LLDT8 could effectively inhibit the secretion of pro-inflammatory and pro-fibrotic factors by macrophages, which could alleviate high glucose-induced renal tissue injury and slow down the process of tissue fibrosis and DN.

Rheumatoid Arthritis Has Won the Battle but Not the War: How Many Joints Will We Save Tomorrow?

Rheumatoid arthritis refers to joint diseases of unclear etiology whose final stages can lead to unbearable pain and complete immobility of the affected joints. As one of the most widely known diseases of the joints, it serves as a study target for a large number of research groups and pharmaceutical companies. Modern treatment with anti-inflammatory drugs, including janus kinase (JAK) inhibitors, monoclonal antibodies, and botanicals (polyphenols, glycosides, alkaloids, etc.) has achieved some success and hope for improving the course of the disease. However, existing drugs against RA have a number of side effects which push researchers to elaborate on more selective and effective drug candidates. The avant-garde of research, which aims to develop treatment of rheumatoid arthritis using antisense oligonucleotides along with nonsteroidal drugs and corticosteroids against inflammation, increases the chances of success and expands the arsenal of drugs. The primary goal in the treatment of this disease is to find therapies that allow patients with rheumatoid arthritis to move their joints without pain. The main purpose of this review is to show the victories and challenges for the treatment of rheumatoid arthritis and the tortuous but promising path of research that aims to help patients experience the joy of freely moving joints without pain.

Tripterygium hypoglaucum extract ameliorates adjuvant-induced arthritis in mice through the gut microbiota

Traditionally, Tripterygium hypoglaucum (Levl.) Hutch (THH) are widely used in Chinese folk to treat rheumatoid arthritis (RA). This study aimed to investigate whether the anti-RA effect of THH is related with the gut microbiota. The main components of prepared THH extract were identified by HPLC-MS. C57BL/6 mice with adjuvant-induced arthritis (AIA) were treated with THH extract by gavage for one month. THH extract significantly alleviated swollen ankle, joint cavity exudation, and articular cartilage destruction in AIA mice. The mRNA and protein levels of inflammatory mediators in muscles and plasma indicated that THH extract attenuated inflammatory responses in the joint by blocking TLR4/MyD88/MAPK signaling pathways. THH extract remarkably restored the dysbiosis of the gut microbiota in AIA mice, featuring the increases of Bifidobacterium, Akkermansia, and Lactobacillus and the decreases of Butyricimonas, Parabacteroides, and Anaeroplasma. Furthermore, the altered bacteria were closely correlated with physiological indices and drove metabolic changes of the intestinal microbiota. In addition, antibiotic-induced pseudo germ-free mice were employed to verify the role of the intestinal flora. Strikingly, THH treatment failed to ameliorate the arthritis symptoms and signaling pathways in pseudo germ-free mice, which validates the indispensable role of the intestinal flora. For the first time, we demonstrated that THH extract protects joint inflammation by manipulating the intestinal flora and regulating the TLR4/MyD88/MAPK signaling pathway. Therefore, THH extract may serve as a microbial modulator to recover RA in clincial practice.ver RA in clincial practice.

A comprehensive review on celastrol, triptolide and triptonide: Insights on their pharmacological activity, toxicity, combination therapy, new dosage form and novel drug delivery routes

Celastrol, triptolide and triptonide are the most significant active ingredients of Tripterygium wilfordii Hook F (TWHF). In 2007, the 'Cell' journal ranked celastrol, triptolide, artemisinin, capsaicin and curcumin as the five natural drugs that can be developed into modern medicinal compounds. In this review, we collected relevant data from the Web of Science, PubMed and China Knowledge Resource Integrated databases. Some information was also acquired from government reports and conference papers. Celastrol, triptolide and triptonide have potent pharmacological activity and evident anti-cancer, anti-tumor, anti-obesity and anti-diabetes effects. Because these compounds have demonstrated unique therapeutic potential for acute and chronic inflammation, brain injury, vascular diseases, immune diseases, renal system diseases, bone diseases and cardiac diseases, they can be used as effective drugs in clinical practice in the future. However, celastrol, triptolide and triptonide have certain toxic effects on the liver, kidney, cholangiocyte heart, ear and reproductive system. These shortcomings limit their clinical application. Suitable combination therapy, new dosage forms and new routes of administration can effectively reduce toxicity and increase the effect. In recent years, the development of different targeted drug delivery formulations and administration routes of celastrol and triptolide to overcome their toxic effects and maximise their efficacy has become a major focus of research. However, in-depth investigation is required to elucidate the mechanisms of action of celastrol, triptolide and triptonide, and more clinical trials are required to assess the safety and clinical value of these compounds.

Combined multi-omics and network pharmacology approach reveals the role of Tripterygium Wilfordii Hook F in treating HIV immunological non-responders

BACKGROUND

The HIV-1 infected immunological non-responders (INRs) are characterized by poor immune reconstitution after long-term treatment. Tripterygium Wilfordii Hook F (TwHF) pill is a traditional Chinese patent drug with extensive immunosuppressive effects and has been clinically proven efficacy in treating INRs.

PURPOSE

The therapeutic mechanism of TwHF pills in the treatment of INRs was investigated by the combined multi-omics analysis on clinical samples and network pharmacology approach.

METHODS

Clinically, the peripheral blood mononuclear cells (PBMC) samples of TwHF-treated INRs from different time points were collected to conduct the transcriptomic and proteomic profiling. Key effector pathways of TwHF were enriched and analyzed by the ingenuity pathway analysis (IPA). Computationally, the TwHF-related compounds were obtained from traditional Chinese medicine databases, and literature search and structural prediction were performed to identify TwHF-related targets. Integrated with the INR-related targets, the 'TwHF-compounds-targets-INR' network was constructed to analyze core effector targets by centrality measurement. Experimentally, the effects of TwHF compounds on the T cells activation and expression of identified targets were evaluated with in vitro cell culture.

RESULTS

33 INRs were included and treated with TwHF pills for 17 (IQR, 12-24) months. These patients experienced rapid growth in the CD4⁺ T cell counts and decreased T cell activation. The multi-omics analysis showed that the interferon (IFN)-signaling pathway was significantly inhibited after taking TwHF pills. The network pharmacology predicted the central role of the signal transducer and activator of transcription 1 (STAT1) in the 'TwHF-compounds-targets-INR' network. Further bioinformatic analysis predicted STAT1 would regulate over 58.8% of identified down-regulated genes. Cell experiments validated that triptolide (TPL) would serve as the major bioactivity compound of TwHF pills to inhibit the immune cell activation, the production of IFN-γ, the expression of downstream IFN-stimulated genes, and the phosphorylation of STAT1.

CONCLUSION

Our research is the first to systemic verify the mechanisms of TwHF in treating INRs. The IFN signaling pathway and the STAT1 would be the major effector targets of TwHF pills in treating INRs. The TPL would be the major bioactive compound to inhibit the IFN response and the phosphorylation of STAT1. Our observations suggest the basis for further application of TPL analogous in treating INRs.

Therapeutic effect of (5R)-5-hydroxytriptolide (LLDT-8) in SIV infected rhesus monkeys

BACKGROUNDS

Human immunodeficiency virus (HIV) infections induce robust, generalized inflammatory responses and lead to pathological systemic immune activation. This abnormal immune status persists despite successful antiretroviral therapy (ART). Immune modulating strategies in conjunction with ART were tried to reduce abnormal immune activation. Previously, we demonstrated that Tripterygium Wilfordii Hook F has been shown immunosuppressive activity in HIV patients. (5R)-5-hydroxytriptolide (LLDT-8), a new analog of triptolide, and the most active ingredient of Tripterygium Wilfordii Hook F, has been shown to have lower cytotoxicity. However, the role of LLDT-8 in HIV or simian immunodeficiency virus (SIV) needs to be explored.

METHODS

Six male adult Chinese rhesus monkeys were enrolled in our study. All of them were healthy and negative for SIV, and chronically SIVmac239 infected macaques were treated with LLDT-8 combined with ART (n = 4) or ART only (n = 2) after 14 weeks of infection. ART was determined at week 33, and LLDT-8 was continued until week 48. T cell immune activation and inflammation were compared during the period, and viral rebound time and reservoir were supervised after stopping ART.

RESULTS

The RNA level of the two groups continued to decline after initiating ART, RNA of 4 rhesus monkeys declined to the lower limit of detection at week 20. LLDT-8 administration combined with ART did not affect T cell activation and plasma levels of IL-6 and CRP. The viral load of all the macaques in both groups was rebounded 2 weeks after ART discontinuation. Furthermore, no significant decrease of SIV DNA was observed in the LLDT-8 treatment group.

CONCLUSIONS

LLDT-8 administration during chronic SIV infection had no effect on T cell activation and plasma levels; Furthermore, LLDT-8 may not contribute to suppression of viral rebound and reservoir. These results suggest that LLDT-8 is unlikely to reduce immune activation and viral persistence without additional interventions.

Applications and Mechanisms of Tripterygium Wilfordii Hook. F. and its Preparations in Kidney Diseases

Tripterygium wilfordii Hook. f. (TwHF) is a Chinese botanical drug containing a large number of metabolites. The discovered and recognized anti-inflammatory and immune-regulating effects have made it attract more and more attentions in trials and clinical researches. The extraction and processing of TwHF for pharmaceuticals is a manifestation of the role of traditional Chinese medicine. However, TwHF is toxic. Optimization of TwHF preparations has become a requirement for the development of TwHF pharmaceuticals. Our article introduces the main preparations of TwHF on the Chinese market and their characteristics. In particular, we summarize the clinical applications and influential mechanisms of TwHF and its preparations in kidney diseases. Considering that nephropathy is closely related to immune inflammation and TwHF is a botanical drug with a high number of metabolites, the application of TwHF in kidney diseases may be much more complicated. By revealing the role and mechanisms of TwHF in kidney diseases, this study aims to provide more insights to basic and clinical studies about nephropathy.

LncRNAs and Rheumatoid Arthritis: From Identifying Mechanisms to Clinical Investigation

Rheumatoid arthritis (RA) is a systemic chronic autoinflammatory disease, and the synovial hyperplasia, pannus formation, articular cartilage damage and bone matrix destruction caused by immune system abnormalities are the main features of RA. The use of Disease Modifying Anti-Rheumatic Drugs (DMARDs) has achieved great advances in the therapy of RA. Yet there are still patients facing the problem of poor response to drug therapy or drug intolerance. Current therapy methods can only moderate RA progress, but cannot stop or reverse the damage it has caused. Recent studies have reported that there are a variety of long non-coding RNAs (LncRNAs) that have been implicated in mediating many aspects of RA. Understanding the mechanism of LncRNAs in RA is therefore critical for the development of new therapy strategies and prevention strategies. In this review, we systematically elucidate the biological roles and mechanisms of action of LncRNAs and their mechanisms of action in RA. Additionally, we also highlight the potential value of LncRNAs in the clinical diagnosis and therapy of RA.

Protective role of (5R)-5-hydroxytriptolide in lipopolysaccharide-induced acute lung injury by suppressing dendritic cell activation

(5R)-5-hydroxytriptolide (LLDT-8) is a triptolide derivative with potent immunosuppressive property. This study aimed to investigate whether LLDT-8 manifests anti-inflammatory effects and influences dendritic cell function in early phase of lipopolysaccharide (LPS)-induced acute lung injury (ALI). C57BL/6 mice were administrated with LPS (6 mg/kg) to induce ALI and LLDT-8 were administrated at different doses (0.125 mg, 0.25 mg, 0.5 mg/kg). Histological changes were demonstrated by hematoxylin and eosin staining. Activation of dendritic cells were measured by flow cytometry. The concentrations of cytokines were measured by enzyme-linked immunosorbent assay. Bone marrow-derived dendritic cells (BMDCs) were acquired to explore immunosuppressive effects of LLDT-8 in vitro. Expression of Toll-like receptor 4 (TLR4), phosphorylation of inhibitor kappa B alpha (IκBα) and nuclear translocation of nuclear factor kappa B (NF-κB) were explored by immunoblot. Immunosuppressive property of LLDT-8-treated BMDCs were measured by adoptive transfer. The survival rate of ALI mice was significantly improved by LLDT-8 at the dose of 0.25 mg/kg. Moreover, systemic inflammatory response was suppressed and lung injury was relieved. LLDT-8 inhibited the activation of dendritic cells in vivo and influenced maturation, apoptosis and cytokine secretion capacity of BMDCs in vitro. Additionally, LLDT-8-treated BMDCs manifested reduced expression of TLR4, phosphorylation of IκBα and nuclear translocation of NF-κB. Adoptive transfer of LLDT-8-treated BMDCs alleviated LPS-induced lung injury. LLDT-8 also had protective effects on Pseudomonas aeruginosa-induced ALI. In conclusion, LLDT-8 played a protective role against ALI and suppressed dendritic cell activation potentially through affecting TLR4 expression and NF-κB signaling.

Triptolide promotes the apoptosis and attenuates the inflammation of fibroblast-like synoviocytes in rheumatoid arthritis by down-regulating lncRNA ENST00000619282

Rheumatoid arthritis (RA), recognized as a common chronic autoimmune disease, is characterized by the excessive proliferation and inflammatory infiltration of fibroblast-like synoviocytes (FLS). In this study, our purpose is to elucidate the mechanisms of triptolide (TPL) in the treatment of RA by regulating the long non-coding RNA (lncRNA) ENST00000619282, which promoted apoptosis and reduced inflammatory infiltration of FLS in RA (RA-FLS). RA-FLS was treated with different concentrations of TPL at different time points. CCK-8 assay, ELISA, RT-qPCR, immunofluorescence, TUNEL assay, and the transmission electron microscopy were used to measure the changes of cell viability, apoptosis, and the release of inflammatory cytokines. Next, the involvement of ENST00000619282 in TPL-mediated protection against RA was explored. ENST00000619282 expression was significantly increased in the peripheral blood mononuclear cells (PBMCs) of RA patients. ENST0000061928 expression in RA PBMCs was positively associated with ESR, RF, CCP, and DAS28, while TPL treatment led to a downregulation of ENST00000619282. In addition, ENST00000619282 was significantly increased in RA-FLS. Furthermore, overexpression of ENST00000619282 elevated the levels of pro-apoptotic and pro-inflammatory factors, while reduced the levels of anti-apoptotic proteins and antiinflammatory factors. Besides, TPL treatment could reverse these effects by ENST00000619282 overexpression. The anti-RA potential of TPL might be achieved by downregulating ENST00000619282, thereby promoting apoptosis, and reducing the inflammatory response in RA.

Study of the Active Components and Molecular Mechanism of Tripterygium wilfordii in the Treatment of Diabetic Nephropathy

We aimed to explore the active ingredients and molecular mechanism of Tripterygium wilfordii (TW) in the treatment of diabetic nephropathy (DN) through network pharmacology and molecular biology. First, the active ingredients and potential targets of TW were obtained through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and related literature materials, and Cytoscape 3.7.2 software was used to construct the active ingredient-target network diagram of TW. Second, the target set of DN was obtained through the disease database, and the potential targets of TW in the treatment of DN were screened through a Venn diagram. A protein interaction network diagram (PPI) was constructed with the help of the String platform and Cytoscape 3.7.2. Third, the ClueGO plug-in tool was used to enrich the GO biological process and the KEGG metabolic pathway. Finally, molecular docking experiments and cell pathway analyses were performed. As a result, a total of 52 active ingredients of TW were screened, and 141 predicted targets and 49 target genes related to DN were identified. The biological process of GO is mediated mainly through the regulation of oxygen metabolism, endothelial cell proliferation, acute inflammation, apoptotic signal transduction pathway, fibroblast proliferation, positive regulation of cyclase activity, adipocyte differentiation and other biological processes. KEGG enrichment analysis showed that the main pathways involved were AGE-RAGE, vascular endothelial growth factor, HIF-1, IL-17, relaxin signalling pathway, TNF, Fc epsilon RI, insulin resistance and other signaling pathways. It can be concluded that TW may treat DN by reducing inflammation, reducing antioxidative stress, regulating immunity, improving vascular disease, reducing insulin resistance, delaying renal fibrosis, repairing podocytes, and reducing cell apoptosis, among others, with multicomponent, multitarget and multisystem characteristics.

Tubule-specific protein nanocages potentiate targeted renal fibrosis therapy

Background

Despite the dramatic advances in modern medicine, efficient therapeutic measures for renal fibrosis remain limited. Celastrol (CLT) is effective in treating renal fibrosis in rat models, while causing severe systemic toxicity. Thus, we designed a tubule-specific nanocage (K3-HBc NCs) that effectively deliver CLT to tubular epithelial cell in a virus-like manner. The targeting ligand (K3) to tubular epithelial cells was displayed on the surface of Hepatitis B core protein (HBc) NCs by genetic fusion to the major immunodominant loop region. Ultra-small CLT nanodots were subtly encapsulated into the cavity through electrostatic interaction with the disassembly and reassembly of K3-HBc NCs, to yield K3-HBc/CLT complex. The efficacy of K3-HBc/CLT NCs were demonstrated in Unilateral ureteral obstruction (UUO)-induced renal fibrosis.

Results

The self-assembled K3-HBc/CLT could specifically target tubular epithelial cells via affinity with K3 ligand binding to the megalin receptor, significantly attenuating renal fibrosis. Remarkably, K3-HBc/CLT NCs significantly increased therapeutic efficacy and reduced the systemic toxicity in comparison with free CLT in UUO-induced mouse renal fibrosis model. Importantly, analysis of RNA sequencing data suggested that the anti-fibrotic effect of K3-HBc/CLT could be attributed to suppression of premature senescence in tubular epithelial cells via p21^Cip1 and p16^Ink4a pathway.

Conclusion

The tubule-specific K3-HBc/CLT represented a promising option to realize precise treatment for renal fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00900-w.

Triptolide analog LLDT-8 ameliorates psoriasis-like dermatitis in BALB/c mice via suppressing the IL-36α signaling pathway

Triptolide has shown a good immunosuppressive effect on autoimmune diseases. However, the toxicity limited its widely clinical practice. In this study, we investigated the effects and underlying mechanisms of (5R)-5-hydroxytriptolide (LLDT-8), a novel triptolide derivative, on a murine psoriasis-like dermatitis model and related cell lines. Here, we showed that LLDT-8 significantly attenuated symptoms of psoriasis-like dermatitis induced by imiquimod (IMQ, a TLR7 agonist) by reducing the psoriasis area and severity index (PASI) score and inflammatory parameters. The action of LLDT-8 was involved in down-regulated interleukin (IL)-36α expression and blocked IL-36α pathway by LC-MS-based label-free quantitative (LFQ) proteomic approach and further experiments. Meanwhile, we observed that LLDT-8 significantly inhibited the expression of IL-36α in R837-treated bone marrow-derived dendritic cells (BMDCs). In conclusion, LLDT-8 notably alleviated IMQ-induced psoriasis-like skin inflammation via suppressing the IL-36α signaling pathway, suggesting LLDT-8 might be a potential drug for the treatment of psoriasis.

The Exploration of Novel Pharmacophore Characteristics and Multidirectional Elucidation of Structure-Activity Relationship and Mechanism of Sesquiterpene Pyridine Alkaloids from Tripterygium Based on Computational Approaches

Sesquiterpene pyridine alkaloids are a large group of highly oxygenated sesquiterpenoids, which are characterized by a macrocyclic dilactone skeleton containing 2-(carboxyalkyl) nicotinic acid and dihydro-β-agarofuran sesquiterpenoid, and are believed to be the active and less toxic components of Tripterygium. In this study, 55 sesquiterpene pyridine alkaloids from Tripterygium were subjected to identification of pharmacophore characteristics and potential targets analysis. Our results revealed that the greatest structural difference of these compounds was in the pyridine ring and the pharmacophore model-5 (Pm-05) was the best model that consisted of three features including hydrogen bond acceptor (HBA), hydrogen bond donor (HBD), and hydrophobic (HY), especially hydrophobic group located in the pyridine ring. It was proposed that 2-(carboxyalkyl) nicotinic acid part possessing a pyridine ring system was not only a pharmacologically active center but also a core of structural diversity of alkaloids from Tripterygium wilfordii. Furthermore, sesquiterpene pyridine alkaloids from Tripterygium were predicted to target multiple proteins and pathways and possibly played essential roles in the cure of Alzheimer's disease, breast cancer, Chagas disease, and nonalcoholic fatty liver disease (NAFLD). They also had other pharmacological effects, depending on the binding interactions between pyridine rings of these compounds and active cavities of the target genes platelet-activating factor receptor (PTAFR), cannabinoid receptor 1 (CNR1), cannabinoid receptor 1 (CNR2), squalene synthase (FDFT1), and heat shock protein HSP 90-alpha (HSP90AA1). Taken together, the results of this present study indicated that sesquiterpene pyridine alkaloids from Tripterygium are promising candidates that exhibit potential for development as medicine sources and need to be promoted.

Use of Salmonella Bacteria in Cancer Therapy: Direct, Drug Delivery and Combination Approaches

Over the years, conventional cancer treatments, such as chemotherapy with only a limited specificity for tumors, have undergone significant improvement. Moreover, newer therapies such as immunotherapy have undergone a revolution to stimulate the innate as well as adaptive immune responses against the tumor. However, it has been found that tumors can be selectively colonized by certain bacteria, where they can proliferate, and exert direct oncolytic effects as well as stimulating the immune system. Bacterial-mediated cancer therapy (BMCT) is now one example of a hot topic in the antitumor field. Salmonella typhimurium is a Gram-negative species that generally causes self-limiting gastroenteritis in humans. This species has been designed and engineered in order to be used in cancer-targeted therapeutics. S. typhimurium can be used in combination with other treatments such as chemotherapy or radiotherapy for synergistic modification of the tumor microenvironment. Considerable benefits have been shown by using engineered attenuated strains for the diagnosis and treatment of tumors. Some of these treatment approaches have received FDA approval for early-phase clinical trials. This review summarizes the use of Salmonella bacteria for cancer therapy, which could pave the way towards routine clinical application. The benefits of this therapy include an automatic self-targeting ability, and the possibility of genetic manipulation to produce newly engineered attenuated strains. Nevertheless, Salmonella-mediated anticancer therapy has not yet been clinically established, and requires more research before its use in cancer treatment.

The Toxicity and Attenuation Methods of Toxic Chinese Materia Medica for its Reasonable Application: A Review

Over a millennia, traditional Chinese medicine (TCM) has been used to treat various diseases in China. In recent years, more and more Chinese materia medica (CMM) have been studied in scientific research projects, applied in clinical practice, and their extracts have even appeared in some health products. However, the toxicity of some CMM is often overlooked, including hepatotoxicity, nephrotoxicity, neurotoxicity, cardiotoxicity, etc. In this review, the toxic components and their toxicological mechanisms of some toxic CMM were listed according to the chemical structure classification of toxic components. Afterwards, the traditional methods (processing and compatibility) and modern methods (structural modification, biotransformation, etc.) of attenuation of CMM were discussed. Since ancient times, it has been said that "fight fire with fire, fight poison with poison," and toxic CMM are of great significance in the treatment of difficult and severe diseases. The rational application of toxic CMM and their components in clinical practice was also exemplified in this review. While the pharmacological effects of TCMs have been emphasized, the scientific attenuation and rational application of toxic components should be concerned. We hope this review can provide a reference for future related research.

Triptolide: reflections on two decades of research and prospects for the future

Covering: 2000 to 2020 Triptolide is a bioactive diterpene triepoxide isolated from Tripterygium wilfordii Hook F, a traditional Chinese medicinal plant whose extracts have been used as anti-inflammatory and immunosuppressive remedies for centuries. Although triptolide and its analogs exhibit potent bioactivities against various cancers, and inflammatory and autoimmune diseases, none of them has been approved to be used in the clinic. This review highlights advances in material sourcing, molecular mechanisms, clinical progress and new drug design strategies for triptolide over the past two decades, along with some prospects for the future course of development of triptolide.

Use of Herbal Medications for Treatment of Osteoarthritis and Rheumatoid Arthritis

Arthritis is a chronic condition that affects nearly a quarter of the United States population. Osteoarthritis (OA) and rheumatoid arthritis (RA) are two major forms of arthritis associated with severe joint pain and reduced quality of life. Various pharmacological interventions may be utilized for arthritis treatment when non-pharmacological therapy is insufficient. However, pharmacological therapy can be associated with serious side effects and high costs. Therefore, alternative therapies have been under investigation. Herbal medications have shown the potential for safe and effective management of arthritis. For this review, we attempt to summarize the mechanisms, safety, and efficacy of herbal treatments for OA and RA. After searching electronic databases, we identified nine herbs among 23 clinical trials used for the treatment of OA or RA patients. Improvement of OA and RA symptoms, pain, and inflammation was demonstrated. The herbs exhibited strong anti-inflammatory and anti-oxidant activities, contributing to a reduction in inflammation and tissue damage. Several herbs elucidated new mechanisms for OA and RA treatment as well. Though these herbs have shown promise for OA and RA treatment, more studies and clinical trials are required for determining safety and efficacy, bioactivity, and optimal bioavailability.

Therapeutic Effects of Tryptanthrin and Tryptanthrin-6-Oxime in Models of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease involving joint and bone damage that is mediated in part by proteases and cytokines produced by synovial macrophages and fibroblast-like synoviocytes (FLS). Although current biological therapeutic strategies for RA have been effective in many cases, new classes of therapeutics are needed. We investigated anti-inflammatory properties of the natural alkaloid tryptanthrin (TRYP) and its synthetic derivative tryptanthrin-6-oxime (TRYP-Ox). Both TRYP and TRYP-Ox inhibited matrix metalloproteinase (MMP)-3 gene expression in interleukin (IL)-1β-stimulated primary human FLS, as well as IL-1β–induced secretion of MMP-1/3 by FLS and synovial SW982 cells and IL-6 by FLS, SW982 cells, human umbilical vein endothelial cells (HUVECs), and monocytic THP-1 cells, although TRYP-Ox was generally more effective and had no cytotoxicity in vitro. Evaluation of the therapeutic potential of TRYP and TRYP-Ox in vivo in murine arthritis models showed that both compounds significantly attenuated the development of collagen-induced arthritis (CIA) and collagen-antibody–induced arthritis (CAIA), with comparable efficacy. Collagen II (CII)-specific antibody levels were similarly reduced in TRYP- and TRYP-Ox-treated CIA mice. TRYP and TRYP-Ox also suppressed proinflammatory cytokine production by lymph node cells from CIA mice, with TRYP-Ox being more effective in inhibiting IL-17A, granulocyte-macrophage colony-stimulating factor (GM-CSF), and receptor activator of nuclear factor-κB ligand (RANKL). Thus, even though TRYP-Ox generally had a better in vitro profile, possibly due to its ability to inhibit c-Jun N-terminal kinase (JNK), both TRYP and TRYP-Ox were equally effective in inhibiting the clinical symptoms and damage associated with RA. Overall, TRYP and/or TRYP-Ox may represent potential new directions for the pursuit of novel treatments for RA.

Tripterygium wilfordii Hook F Treatment for Stage IV Diabetic Nephropathy: Protocol for a Prospective, Randomized Controlled Trial

BACKGROUND

Diabetic nephropathy (DN) is a major cause of chronic kidney disease (CKD). There are no effective treatments to prevent or reverse the progression of DN. A preliminary study showed that Tripterygium glycosides from Tripterygium wilfordii Hook F (TwHF) with valsartan decrease proteinuria in patients with DN.

OBJECTIVES

The objective of the present study is to investigate the efficacy and safety of Tripterygium glycosides from TwHF, a traditional Chinese medicine, for the treatment of DN. Methods and Analysis. This is a prospective, single-center randomized controlled trial. Seventy participants diagnosed with DN were recruited and randomized 1 : 1 to two groups: (1) angiotensin receptor blocker (ARB) combined with TwHF and (2) ARB-only. The treatment period is 48 weeks. The primary endpoint is 24 h proteinuria decreased level (reduction of 30% vs. baseline) after 48 weeks of treatment. The secondary endpoints are (1) all-cause and cardiovascular-related mortality, (2) development of ESRD (serum creatinine > 530.4 μmol/L or estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m2), (3) the need for renal replacement therapy, and (4) increased serum creatinine (2-fold higher than the baseline value or ≥442 μmol/L, with confirmation of the initial results after 4 weeks). A health economics analysis will be carried out. Discussion. A meta-analysis of RCTs carried out in patients with stage 4 (Mogensen classification) diabetic CKD showed that TwHF combined with an ARB was more effective than an ARB alone when considering 24 h proteinuria and serum albumin, but with an increase in adverse event (AE) frequency of 8%. This is a prospective clinical trial that may provide information on a safe and effective novel method for the treatment of DN, especially for patients with macroproteinuria. Ethics and Dissemination. The protocol is approved by the ethics committee of Beijing Hospital (2016BJYYEC-059-02). The results will be disseminated through peer-reviewed publications and international conferences. This trial is registered with ChiCTR-IOR-17010623.

The effects of triptolide on the cellular activity of cryopreserved rat sciatic nerves and nerve regeneration after allotransplantation

Purpose: To investigate the effects of triptolide (T10) on the cellular activity of cryopreserved rat sciatic nerves and nerve regeneration after allotransplantation.Materials and methods: After the optimal T10 concentration was determine, sciatic nerve fragments from Sprague-Dawley (SD) rats were randomly divided into 5 groups: the fresh nerve group (group A), the Dulbecco's modified Eagle's medium (DMEM)-preservation group (group B), the T10-preservation group (group C), the T10-pretreatment, DMEM-preservation group (group D), and the T10-pretreatment, T10-preservation group (group E). The nerves in the preservation groups were preserved at 4 °C for 4 w. Then, either cryopreserved or fresh nerves were used to repair 10-mm sciatic nerve defects in Wistar rats (group A', group B', group C', group D', and group E', which correspond to the nerve groups described above); in addition, one fresh homologous transplantation group (group F') was established.Results: Nerve growth factor (NGF) was expressed at significantly higher levels in the groups treated with the T10 solution at 37 °C. After rat sciatic nerves were cryopreserved for 4 w, group E had increased numbers of live nerve cells and increased levels of biological activity (P < 0.001) and reduced levels of immunogenicity (P < 0.001) when compared with those for the other groups. Sixteen weeks after transplantation, recipient nerve regeneration in group E' was increased compared with that in groups A', B', C', and D' (P < 0.05).Conclusions: The application of T10 in vitro induced the expression of neurotrophic factors in rat sciatic nerves, increased the biological activity of cryopreserved nerves, reduced immunogenicity, and promoted recipient nerve regeneration after allotransplantation.

(5R)-5-Hydroxytriptolide (LLDT-8) induces substantial epigenetic mediated immune response network changes in fibroblast-like synoviocytes from rheumatoid arthritis patients

Tripterygium is a traditional Chinese medicine that has widely been used in the treatment of rheumatic disease. (5R)-5-hydroxytriptolide (LLDT-8) is an extracted compound from Tripterygium, which has been shown to have lower cytotoxicity and relatively higher immunosuppressive activity when compared to Tripterygium. However, our understanding of LLDT-8-induced epigenomic impact and overall regulatory changes in key cell types remains limited. Doing so will provide critically important mechanistic information about how LLDT-8 wields its immunosuppressive activity. The purpose of this study was to assess the effects of LLDT-8 on transcriptome including mRNAs and long non-coding RNA (lncRNAs) in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) by a custom genome-wide microarray assay. Significant differential expressed genes were validated by QPCR. Our work shows that 394 genes (281 down- and 113 up-regulated) were significantly differentially expressed in FLS responding to the treatment of LLDT-8. KEGG pathway analysis showed 20 pathways were significantly enriched and the most significantly enriched pathways were relevant to Immune reaction, including cytokine-cytokine receptor interaction (P = 4.61 × 10⁻¹³), chemokine signaling pathway (P = 1.01 × 10⁻⁵) and TNF signaling pathway (P = 2.79 × 10⁻⁴). Furthermore, we identified 618 highly negatively correlated lncRNA-mRNA pairs from the selected significantly differential lncRNA and mRNA including 27 cis-regulated and 591 trans-regulated lncRNA-mRNAs modules. KEGG and GO based function analysis to differential lncRNA also shown the enrichment of immune response. Finally, lncRNA-transcription factor (TF) and lncRNA-TF-mRNA co-expression network were constructed with high specific network characteristics, indicating LLDT-8 would influence the expression network within the whole FLS cells. The results indicated that the LLDT-8 would mainly influence the FLS cells systemically and specially in the process of immune related pathways.

Overview of Molecular Mechanisms Involved in Herbal Compounds for Inhibiting Osteoclastogenesis from Macrophage Linage RAW264.7

Differentiation from RAW264.7 cells to osteoclasts rely on many signaling pathways, such as NF-κB, MAPK, Akt and others. However, the specific underlying mechanisms are not clear. Recently, much works have focused on the inhibitory effects of plant derived compounds in the differentiation from RAW264.7 to osteoclasts. However, the specific mechanisms remain unclear. In this paper, we summarize a lot of plant derived compounds which exert blocking effect on the progression of differentiation via signaling pathways.

Treatment of Neurodegenerative Diseases with Bioactive Components of Tripterygium wilfordii

Tripterygium wilfordii Hook F. (TWHF), a traditional Chinese medicine, has been widely used to treat autoimmune and inflammatory diseases including rheumatoid arthritis, systemic lupus erythematosus and dermatomyositis in China. Recently, studies have demonstrated that the bioactive components of TWHF have effective therapeutic potential for neurodegenerative diseases including Alzheimer's disease, Parkinson's disease and Multiple Sclerosis. In this paper, we summarize the research progress of triptolide and celastrol (the two major TWHF components) as well as their analogues in the treatment of neurodegenerative diseases. In addition, we review and discuss the molecular mechanisms and structure features of those two bioactive TWHF components, highlighting their therapeutic promise in neurodegenerative diseases.

CYP3A4 inducer and inhibitor strongly affect the pharmacokinetics of triptolide and its derivative in rats

Triptolide is the most active ingredient of Tripterygium wilfordii Hook F, which is used to treat rheumatoid arthritis. (5R)-5-Hydroxytriptolide is a hydroxylation derivative of triptolide with a reduced toxicity. To investigate the metabolic enzymes of the two compounds and the drug-drug interactions with enzyme inducers or inhibitors, a series of in vitro and in vivo experiments were conducted. In vitro studies using recombinant human cytochrome P450 enzyme demonstrated that cytochrome P450 3A4 (CYP3A4) was predominant in the metabolism of triptolide and (5R)-5-hydroxytriptolide, accounting for 94.2% and 64.2% of the metabolism, respectively. Pharmacokinetics studies were conducted in male SD rats following administration of triptolide or (5R)-5-hydroxytriptolide (0.4 mg/kg, po). The plasma exposure to triptolide and (5R)-5-hydroxytriptolide in the rats was significantly increased when co-administered with the CYP3a inhibitor ritonavir (30 mg/kg, po) with the values of AUC_0-∞ (area under the plasma concentration-time curve from time zero extrapolated to infinity) being increased by 6.84 and 1.83 times, respectively. When pretreated with the CYP3a inducer dexamethasone (50 mg·kg^-1·d^-1, for 3 d), the AUC_0-∞ values of triptolide and (5R)-5-hydroxytriptolide were decreased by 85.4% and 91.4%, respectively. These results suggest that both triptolide and (5R)-5-hydroxytriptolide are sensitive substrates of CYP3a. Because of their narrow therapeutic windows, clinical drug-drug interaction studies should be carried out to ensure their clinical medication safety and efficacy.

The Effect of Triptolide in Rheumatoid Arthritis: From Basic Research towards Clinical Translation

Triptolide (TP), a major extract of the herb Tripterygium wilfordii Hook F (TWHF), has been shown to exert potent pharmacological effects, especially an immunosuppressive effect in the treatment of rheumatoid arthritis (RA). However, its multiorgan toxicity prevents it from being widely used in clinical practice. Recently, several attempts are being performed to reduce TP toxicity. In this review, recent progress in the use of TP for RA, including its pharmacological effects and toxicity, is summarized. Meanwhile, strategies relying on chemical structural modifications, innovative delivery systems, and drug combinations to alleviate the disadvantages of TP are also reviewed. Furthermore, we also discuss the challenges and perspectives in their clinical translation.

The Calcium-Induced Regulation in the Molecular and Transcriptional Circuitry of Human Inflammatory Response and Autoimmunity

Rheumatoid arthritis synovial fibroblasts (RASFs) are fundamental effector cells in RA driving the joint inflammation and deformities. Celastrol is a natural compound that exhibits a potent anti-arthritic effect promoting endoplasmic reticulum (ER) stress mediated by intracellular calcium (Ca²⁺) mobilization. Ca²⁺ is a second messenger regulating a variety of cellular processes. We hypothesized that the compound, celastrol, affecting cytosolic Ca²⁺ mobilization could serve as a novel strategy to combat RA. To address this issue, celastrol was used as a molecular tool to assay the inflammatory gene expression profile regulated by Ca²⁺. We confirmed that celastrol treatment mobilized cytosolic Ca²⁺ in patient-derived RASFs. It was found that 23 genes out of 370 were manipulated by Ca²⁺ mobilization using an inflammatory and autoimmunity PCR array following independent quantitative PCR validation. Most of the identified genes were downregulated and categorized into five groups corresponding to their cellular responses participating in RA pathogenesis. Accordingly, a signaling network map demonstrating the possible molecular circuitry connecting the functions of the products of these genes was generated based on literature review. In addition, a bioinformatics analysis revealed that celastrol-induced Ca²⁺ mobilization gene expression profile showed a novel mode of action compared with three FDA-approved rheumatic drugs (methotrexate, rituximab and tocilizumab). To the best of our knowledge, this is a pioneer work charting the Ca²⁺ signaling network on the regulation of RA-associated inflammatory gene expression.

(5R)-5-hydroxytriptolide ameliorates anti-glomerular basement membrane glomerulonephritis in NZW mice by regulating Fcγ receptor signaling

(5R)-5-hydroxytriptolide (LLDT-8) is a novel triptolide analog that has been identified as a promising candidate for treating autoimmune diseases and has been shown to be effective in treating murine collagen-induced arthritis and lupus nephritis. In the present study, we investigated the therapeutic effect and possible mechanism of action of LLDT-8 in a murine anti-glomerular basement membrane (GBM) glomerulonephritis model. NZW mice were injected with rabbit anti-GBM serum (500 μL, ip). The mice were orally treated with LLDT-8 (0.125 mg/kg, every other day) or a positive control prednisolone (2 mg/kg every day) for 14 d. Blood and urine samples as well as spleen and kidney tissues were collected for analyses. LLDT-8 treatment did not affect the generation of mouse anti-rabbit antibodies. LLDT-8 significantly reversed established proteinuria, improved renal histopathology and attenuated renal dysfunction in glomerulonephritis mice. Furthermore, LLDT-8 inhibited inflammation in the kidney evidenced by significantly decreasing C3 and IgG deposition, reducing the levels of the pathogenic cytokines TNF-α, IL-6, IL-17, and IFN-γ, and reducing related chemokine expression and leukocyte infiltration in kidneys. Moreover, LLDT-8 treatment significantly increased the expression of FcγRIIB in the kidney and spleen. In addition, the treatment restored the reduced expression of FcγRIIB on the surface of kidney effector cells, CD11b⁺ cells, and interfered with FcγR-dependent signaling, especially FcγRIIB-mediated downstream kinases, such as BTK. These results demonstrate that LLDT-8 ameliorates anti-GBM glomerulonephritis by regulating the Fcγ receptor signaling.

Efficacy and safety of Tripterygium wilfordii Hook F for CKD in Mainland China: A systematic review and meta-analysis

Tripterygium wilfordii Hook F (TwHF) is a promising Chinese traditional medicine used to significantly reduce proteinuria and improve renal function. However, its efficacy and safety in treatment of chronic kidney disease need to be further explored in order to promote its application in clinics. This review compared the efficacy and safety of TwHF with the placebo, conventional Western medicine and other immunosuppressive medicine in a range of kidney disorders. One hundred three randomized controlled trials were included. TwHF therapy decreased 24-hr proteinuria by 0.59 g/day (95% confidence interval [CI; -0.68, -0.50]), serum creatinine level by 1.93 μmol/L (95% CI [-3.69, -0.17]), and blood urea nitrogen level by 0.24 mmol/L (95% CI [-0.41, -0.07]); increased the total effective rate by 27% (95% CI [1.24, 1.30]); and decreased the incidence of adverse reactions by 19% (95% CI [0.68, 0.96]) overall. Meta regression results showed that the duration of therapy and mean age of participants were the major sources of high heterogeneity. Sensitivity analysis demonstrated that our statistic results were relatively stable and credible. The present findings suggested that TwHF possibly has nephroprotective effects by decreasing proteinuria, serum creatinine level, and blood urea nitrogen level and no more adverse reactions compared with control group in most kidney disorders. However, these findings still need to be further confirmed by high-quality trials.

Tripterygium wilfordii Inhibiting Angiogenesis for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic inflammatory disease with a serious pre-vascular inflammatory phase, followed by significant increase in vessel growth. Inhibition of angiogenesis is a novel therapeutic strategy against RA. The Chinese herbal remedy Tripterygium wilfordii, Hook. f. (TwHf) has been reported to be therapeutically efficacious in the treatment of RA. Recent studies have revealed that treatment with TwHf extracts inhibit angiogenesis of RA, thereby elaborately attenuation RA symptom. This review mainly addresses the anti-angiogenesis effect of TwHf in treatment of RA.

A Novel Immunosuppressor, (5R)-5-Hydroxytriptolide, Alleviates Movement Disorder and Neuroinflammation in a 6-OHDA Hemiparkinsonian Rat Model

Parkinson's disease (PD) is one of the most common age-related neurodegenerative diseases. Promising therapies for PD still need to be explored. Immune dysfunction has been found to be involved in PD pathogenesis. Here, a novel immunosuppressor, (5R)-5-hydroxytriptolide (LLDT8), was used to treat 6-hydroxydopamine (6-OHDA)-induced hemiparkinson rats. We found that oral administration of LLDT8 significantly alleviated apomorphine-induced rotations at a dose of 125 µg/kg, and improved performance in cylinder and rotarod tests at a lower dose of 31.25 µg/kg, in 6-OHDA hemiparkinsonian rats. Moreover, loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the 6-OHDA rat was attenuated in response to LLDT8 treatment in a dose-dependent manner. In addition, inflammatory factors IL-1β, IL-6 and TNF-α, were significantly inhibited in LLDT8-treated hemiparkisonian rats, compared with vehicle. Notably, the level of dopamine (DA) in the striatum of PD rats was restored by LLDT8 treatment. Furthermore, we also detected that the disequilibrium of peripheral lymphocytes was reversed by LLDT8 administration. Taken together, the results imply that the immunosuppressor, LLDT8, can rescue dopaminergic neurodegeneration in 6-OHDA hemiparkinsonian rats, thus providing a potential therapeutic strategy for PD.

(5R)-5-hydroxytriptolide ameliorates lupus nephritis in MRL/lpr mice by preventing infiltration of immune cells

(5R)-5-hydroxytriptolide (LLDT-8), a triptolide derivative with low toxicity, was previously reported to have strong immunosuppressive effects both in vitro and in vivo, but it remains unknown whether LLDT-8 has a therapy effect on systemic lupus erythematosus. In this study, we aimed to investigate the therapeutic effects of LLDT-8 on lupus nephritis in MRL/lpr mice, a model of systemic lupus erythematosus. Compared with the vehicle group, different clinical parameters were improved upon LLDT-8 treatment as follows: prolonged life span of mice, decreased proteinuria, downregulated blood urea nitrogen and serum creatinine, reduced glomerular IgG deposits, and ameliorated histopathology. A decreased expression of the inflammatory cytokines IFN-γ, IL-17, IL-6, and TNF-α was also observed in the kidney of LLDT-8 treated MRL/lpr mice. Moreover, infiltration of T cells in the kidney was mitigated after LLDT-8 treatment, corresponding with decreased expression of related chemokines IP-10, Mig, and RANTES in the kidney. The proportion of macrophage and neutrophil cells and related chemokines expression was also reduced in kidneys of LLDT-8-treated mice. In the human proximal tubule epithelial cell line and mouse mesangial cell line, consistent with our in vivo experimental results, LLDT-8 suppressed the expression of related chemokines and IL-6. In summary, LLDT-8 has a therapeutic benefit for lupus nephritis via suppressing chemokine expression and inhibiting immune cell infiltration in kidneys of MRL/lpr mice.

(5R)-5-hydroxytriptolide (LLDT-8) prevents collagen-induced arthritis through OPG/RANK/RANKL signaling in a rat model of rheumatoid arthritis

(5R)-5-hydroxytriptolide (LLDT-8) extracts from Tripterygium have anti-inflammatory, antineoplastic and immunity adjustment functions. The present study used a collagen-induced arthritis (CIA) model to evaluate whether LLDT-8 prevents collagen-induced arthritis, and investigated the signaling underlying this. Male Sprague-Dawley rats were induced to generate CIA, mimicking rheumatoid arthritis (RA). The presence of arthritis was determined using RA progression scores. The inflammatory cytokines interleukin (IL)-1β, IL-6 and nuclear factor-κB were detected using enzyme-linked immunosorbent assay kits. Induced nitric oxide synthase (iNOS) and matrix metalloprotease (MMP)-13 protein expression were measured using western blot analysis. Lastly, reverse transcription-quantitative polymerase chain reaction was used to evaluate osteoprotegerin (OPG) and receptor activator of nuclear factor κB (RANK) gene expression. LLDT-8 improved RA progression scores and reduced the incidence and severity of CIA. Furthermore, LLDT-8 administration inhibited collagen-induced inflammation and iNOS protein expression in arthritic rats. The current data indicated that MMP-13 production was suppressed and OPG/RANKL expression was increased by LLDT-8 treatment in the arthritic rat. The present results suggest that LLDT-8 attenuates CIA through OPG/RANK/RANK ligand signaling in a rat model of RA.

Autophagic degradation of epidermal growth factor receptor in gefitinib-resistant lung cancer by celastrol

Drug resistance of non-small cell lung cancer (NSCLC) is highly correlated to the mutation of the epidermal growth factor receptor (EGFR). Although EGFR tyrosine kinase inhibitors (TKIs) are available clinically, the molecular complexity of NSCLC has made it necessary to search for alternative therapeutic approaches to overcome the drug resistance of NSCLC. In the present study, we identified a triterpene molecule derived from the herbal plant Tripterygium wilfordii, celastrol, as a novel autophagy inducer. We demonstrate that celastrol exhibited selective cytotoxic effect towards EGFR mutant NSCLCs. In addition, celastrol also facilitated the autophagic degradation of Hsp90 client protein including EGFR and Akt on both EGFR wild-type and mutant NSCLCs via calcium-mediated autophagy. Blockage of celastrol-induced autophagic degradation of EGFR by autophagic inhibitor or calcium chelator decreased celastrol-mediated cell death in gefitinib-resistant NSCLCs. Overall, our findings suggest that celastrol may be developed as an effective anticancer agent for treatment of gefitinib-resistant NSCLC in the future.

New Potential Pharmacological Functions of Chinese Herbal Medicines via Regulation of Autophagy

Autophagy is a universal catabolic cellular process for quality control of cytoplasm and maintenance of cellular homeostasis upon nutrient deprivation and environmental stimulus. It involves the lysosomal degradation of cellular components such as misfolded proteins or damaged organelles. Defects in autophagy are implicated in the pathogenesis of diseases including cancers, myopathy, neurodegenerations, infections and cardiovascular diseases. In the recent decade, traditional drugs with new clinical applications are not only commonly found in Western medicines, but also highlighted in Chinese herbal medicines (CHM). For instance, pharmacological studies have revealed that active components or fractions from Chaihu (Radix bupleuri), Hu Zhang (Rhizoma polygoni cuspidati), Donglingcao (Rabdosia rubesens), Hou po (Cortex magnoliae officinalis) and Chuan xiong (Rhizoma chuanxiong) modulate cancers, neurodegeneration and cardiovascular disease via autophagy. These findings shed light on the potential new applications and formulation of CHM decoctions via regulation of autophagy. This article reviews the roles of autophagy in the pharmacological actions of CHM and discusses their new potential clinical applications in various human diseases.

Dephosphorylation of Tak1 at Ser412 greatly contributes to the spermatocyte-specific testis toxicity induced by (5R)-5-hydroxytriptolide in C57BL/6 mice

(5R)-5-Hydroxytriptolide (LLDT-8), a novel triptolide derivative, will proceed to phase II clinical trials for the treatment of rheumatoid arthritis and cancer. However, the selection of disease and patients is largely limited by the testis toxicity, yet toxicity mechanisms are still poorly understood. In this study, LLDT-8 dose and time-dependently decreased the testes weight, germinal cell layers and induced abnormal spermatid development. Analysis of the germ cell-specific marker showed that spermatocytes were more sensitive to LLDT-8, which was confirmed by the in vitro sensitivity assay with spermatocyte-like GC-2spd and sertoli-like TM4 cells. In GC-2spd, LLDT-8 induced G1/S arrest and apoptosis. MAPK activity screening identified that TGF-β activated kinase 1 (Tak1) is critical in LLDT-8 induced apoptosis. LLDT-8 reduced the Tak1 protein and dephosphorylated Tak1 at Ser412 in GC-2spd and the testes, but not in TM4. RNAi mediated depletion or pharmacologic inhibition of Tak1 induced apoptosis in GC-2spd. Meanwhile, activating Tak1 rescued up to 50% of the GC-2spd cells from the apoptosis induced by LLDT-8. Altogether, our study firstly revealed the important role of Tak1 in the survival of spermatocytes, and dephosphorylation of Tak1 at Ser412 may contribute to the spermatocyte-specific testis toxicity induced by LLDT-8.

New strategies in the management of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute and usually monophasic, neurological, demyelinating disease. Although most patients have good outcomes without sequelae after conventional plasma exchange and intravenous immunoglobulin therapy, 20% of patients continue to have severe disease and 5% die of their disease. Therefore, there is an obvious need for more acceptable and efficacious therapies. Experimental autoimmune neuritis (EAN) is the classical animal model for GBS. As there is no specific drug for GBS, several drugs targeting the humoral and cellular components of the immune response have been used to treat EAN in the endeavour to find new treatment alternatives for GBS. This review focused on some new strategies for GBS, which have been reported but have not yet been widely used, and on the main drugs which have been investigated in EAN.