Dioscin, a Steroidal Saponin Isolated from Dioscorea nipponica, Attenuates Collagen-Induced Arthritis by Inhibiting Th17 Cell Response

The role of botanical triterpenoids and steroids in bile acid metabolism, transport, and signaling: Pharmacological and toxicological implications

Bile acids (BAs) are synthesized by the host liver from cholesterol and are delivered to the intestine, where they undergo further metabolism by gut microbes and circulate between the liver and intestines through various transporters. They serve to emulsify dietary lipids and act as signaling molecules, regulating the host's metabolism and immune homeostasis through specific receptors. Therefore, disruptions in BA metabolism, transport, and signaling are closely associated with cholestasis, metabolic disorders, autoimmune diseases, and others. Botanical triterpenoids and steroids share structural similarities with BAs, and they have been found to modulate BA metabolism, transport, and signaling, potentially exerting pharmacological or toxicological effects. Here, we have updated the research progress on BA, with a particular emphasis on new-found microbial BAs. Additionally, the latest advancements in targeting BA metabolism and signaling for disease treatment are highlighted. Subsequently, the roles of botanical triterpenoids in BA metabolism, transport, and signaling are examined, analyzing their potential pharmacological, toxicological, or drug interaction effects through these mechanisms. Finally, a research paradigm is proposed that utilizes the gut microbiota as a link to interpret the role of these important natural products in BA signaling.

The genus Dioscorea L. (Dioscoreaceae), a review of traditional uses, phytochemistry, pharmacology, and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Dioscorea, a member of the Dioscoreaceae family, comprises approximately 600 species and is widely distributed across temperate and tropical regions such as Asia, South Africa, and North America. The traditional medicinal uses of Dioscorea have been documented in Asian and African pharmacological systems. In Asia, this genus is traditionally used to treat respiratory illnesses, rheumatism, diabetes, diarrhea, dysentery, and other conditions. In Africa, this genus has been used to treat human immunodeficiency virus and ring worms. However, the traditional medicinal practices in North America rarely mention the use of this genus.

AIM OF THE STUDY

The aim of this review is to comprehensively review the genus Dioscorea, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. The research also aims to highlight the valuable bioactive compounds within Dioscorea and emphasize the need for further investigations into acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors to contribute to the discovery of novel pharmaceuticals.

MATERIALS AND METHODS

A search for available information on Dioscorea was conducted using scientific databases, including PubMed, ISI-WOS, Scopus, and Google Scholar, as well as recent academic publications from reputable publishers and other literature sources. The search was not limited by language and spanned the literature published between 1950 and 2022.

RESULTS

This article provides a comprehensive review of the Dioscorea genus, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. Extensive research has been conducted on this genus, resulting in the isolation and examination of over 1000 compounds, including steroids, terpenoids, and flavonoids, to determine their biological activities. These activities include anti-tumor, anti-inflammatory, immunomodulatory, neuroprotective, hypoglycemic, and hypolipidemic effects. However, some studies have indicated the potential toxicity of high doses of Dioscorea, highlighting the need for further investigations to assess the safety of this genus. Additionally, this review explores potential avenues for future research and discusses the challenges associated with a comprehensive understanding of the Dioscorea genus.

CONCLUSIONS

Based on the existing literature, it can be concluded that Dioscorea is a valuable source of bioactive compounds that have the potential to treat various disorders. Future research should prioritize the investigation of acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors. This review provides a comprehensive analysis of the Dioscorea genus, emphasizing its potential to enable a deeper exploration of the biological activity mechanisms of these plants and contribute to the discovery of novel pharmaceuticals.

Protective effects of Dioscin against sepsis-induced cardiomyopathy via regulation of toll-like receptor 4/MyD88/p65 signal pathway

BACKGROUND

Dioscin has many pharmacological effects; however, its role in sepsis-induced cardiomyopathy (SIC) is unknown. Accordingly, we concentrate on elucidating the mechanism of Dioscin in SIC rat model.

METHODS

The SIC rat and H9c2 cell models were established by lipopolysaccharide (LPS) induction. The heart rate (HR), left ventricle ejection fraction (LVEF), mean arterial blood pressure (MAP), and heart weight index (HWI) of rats were evaluated. The myocardial tissue was observed by hematoxylin and eosin staining. 4-Hydroxy-2-nonenal (4-HNE) level in myocardial tissue was detected by immunohistochemistry. Superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) activities in serum samples of rats and H9c2 cells were determined by colorimetric assay. Bax, B-cell lymphoma-2 (Bcl-2), toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), phosphorylated-p65 (p-p65), and p65 levels in myocardial tissues of rats and treated H9c2 cells were measured by quantitative real-time PCR and Western blot. Viability and reactive oxygen species (ROS) accumulation of treated H9c2 cells were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and dihydroethidium staining assays.

RESULTS

Dioscin decreased HR and HWI, increased LVEF and MAP, alleviated the myocardial tissue damage, and reduced 4-HNE level in SIC rats. Dioscin reversed LPS-induced reduction on SOD, CAT, GSH, and Bcl-2 levels, and increment on Bax and TLR4 levels in rats and H9c2 cells. Overexpressed TLR4 attenuated the effects of Dioscin on promoting viability, as well as dwindling TLR4, ROS and MyD88 levels, and p-p65/p65 value in LPS-induced H9c2 cells.

CONCLUSION

Protective effects of Dioscin against LPS-induced SIC are achieved via regulation of TLR4/MyD88/p65 signal pathway.

Research progress of targeted therapy regulating Th17/Treg balance in bone immune diseases

Rheumatoid arthritis (RA) and postmenopausal osteoporosis (PMOP) are common bone-immune diseases. The imbalance between helper (Th17) and regulatory T cells (Tregs) produced during differentiation of CD4+ T cells plays a key regulatory role in bone remodelling disorders in RA and PMOP. However, the specific regulatory mechanism of this imbalance in bone remodelling in RA and PMOP has not been clarified. Identifying the regulatory mechanism underlying the Th17/Treg imbalance in RA and PMOP during bone remodelling represents a key factor in the research and development of new drugs for bone immune diseases. In this review, the potential roles of Th17, Treg, and Th17/Treg imbalance in regulating bone remodelling in RA and PMOP have been summarised, and the potential mechanisms by which probiotics, traditional Chinese medicine compounds, and monomers maintain bone remodelling by regulating the Th17/Treg balance are expounded. The maintenance of Th17/Treg balance could be considered as an therapeutic alternative for the treatment of RA and PMOP. This study also summarizes the advantages and disadvantages of conventional treatments and the quality of life and rehabilitation of patients with RA and PMOP. The findings presented her will provide a better understanding of the close relationship between bone immunity and bone remodelling in chronic bone diseases and new ideas for future research, prevention, and treatment of bone immune diseases.

Prevention and treatment of inflammatory arthritis with traditional Chinese medicine: Underlying mechanisms based on cell and molecular targets

Inflammatory arthritis, primarily including rheumatoid arthritis, osteoarthritis and ankylosing spondylitis, is a group of chronic inflammatory diseases, whose general feature is joint dysfunction with chronic pain and eventually causes disability in older people. To date, both Western medicine and traditional Chinese medicine (TCM) have developed a variety of therapeutic methods for inflammatory arthritis and achieved excellent results. But there is still a long way to totally cure these diseases. TCM has been used to treat various joint diseases for thousands of years in Asia. In this review, we summarize clinical efficacies of TCM in inflammatory arthritis treatment after reviewing the results demonstrated in meta-analyses, systematic reviews, and clinical trials. We pioneered taking inflammatory arthritis-related cell targets of TCM as the entry point and further elaborated the molecular targets inside the cells of TCM, especially the signaling pathways. In addition, we also briefly discussed the relationship between gut microbiota and TCM and described the role of drug delivery systems for using TCM more accurately and safely. We provide updated and comprehensive insights into the clinical application of TCM for inflammatory arthritis treatment. We hope this review can guide and inspire researchers to further explore mechanisms of the anti-arthritis activity of TCM and make a great leap forward in comprehending the science of TCM.

The Small-Molecule compound baicalein alleviates experimental autoimmune encephalomyelitis by suppressing pathogenetic CXCR6+ CD4 cells

CXC chemokine receptor6 (CXCR6)-based immunotherapy plays a significant role in autoimmune diseases, however, little is known about possible small compounds that inhibit pathogenic CXCR6⁺ T cells for treating multiple sclerosis (MS). Baicalein, a flavonoid isolated from Scutellarin baicalensis (Huang Qin), was shown to exert therapeutic effects on MS, but the underlying mechanisms are largely unknown. In the current study, we found that baicalein inhibited Th1 and Th17 differentiation in vitro. Oral administration of baicalein (25 mg/kg) significantly reduced the disease severity and the infiltration process, decreased the extent of demyelination in EAE, and selectively blocked IL-17A production and specific antibodies (IgG and IgG₃) in MOG_35-55-induced specific immune responses. In addition, the expression of CD4 cell effectors (CD44^hiCD62L^low) and pathogenic Th17 cells was decreased by baicalein treatment. Furthermore, baicalein treatment largely decreased CXCR6⁺ CD4 and CD8 cells and prominently inhibited CXCR6⁺ Th17 cells in EAE. Taken together, the findings of this study suggest for the first time that baicalein may ameliorate EAE by suppressing pathogenetic CXCR6⁺ CD4 cells.

MW‑9, a chalcones derivative bearing heterocyclic moieties, attenuates experimental autoimmune encephalomyelitis via suppressing pathogenic TH17 cells

Previous studies have indicated that MW-9, a chalcones derivative bearing heterocyclic moieties, has considerable anti-inflammatory activity in vitro. Whether MW-9 may be used to treat inflammation-based diseases, such as multiple sclerosis, remains unknown. The present study was designed to determine the effect and underlying mechanism of MW-9 in experimental autoimmune encephalomyelitis (EAE). Female C57BL/6 mice immunized with MOG_35-55 were treated with or without MW-9, then the clinical scores and other relevant parameters were investigated. Production of cytokines and specific antibodies were monitored by ELISA assays. Surface marker, Treg cell, and intracellular cytokines (IL-17A and IFN-γ) were detected by flow cytometry, and mRNA expression in the helper-T (T_H)17 cell-related signaling pathway was examined by reverse transcription-quantitative (RT-q) PCR analysis. T_H17 cell differentiation assay was performed. Herein, the present results demonstrated that oral administration of MW-9 reduced the severity of disease in EAE mice through slowing down infiltration process, inhibiting the demyelination, blocking anti-MOG_35-55 IgG antibody production (IgG, IgG_2a and IgG₃), and decreasing accumulation of CD11b⁺Gr-1⁺ neutrophils from EAE mice. MW-9 treatments also led to significantly decreased IL-17A production and IL-17 expression in CD4⁺ T-cells, but had no detectable influence on development of T_H1 and T-regulatory cells ex vivo. RT-qPCR analysis showed that within the spinal cords of the mice, MW-9 blocked transcriptional expression of T_H17-associated genes, including Il17a, Il17f, Il6 and Ccr6. In T_H17 cell differentiation assay, MW-9 inhibited differentiation of ‘naïve’ CD4⁺ T-cells into T_H17 cells and reduced the IL-17A production. The data demonstrated that MW-9 could attenuate EAE in part through suppressing the formation and activities of pathogenic T_H17 cells.

Identification of the Natural Steroid Sapogenin Diosgenin as a Direct Dual-Specific RORα/γ Inverse Agonist

The steroid sapogenin diosgenin is a well-known natural product with a plethora of described pharmacological activities including the amelioration of T helper 17 (Th17)-driven pathologies. However, the exact underlying mode of action of diosgenin leading to a dampened Th17 response is still largely unknown and specific molecular targets have yet to be identified. Here, we show that diosgenin acts as a direct ligand and inverse agonist of the nuclear receptor retinoic acid receptor (RAR)-related orphan receptor (ROR)α and RORγ, which are key transcription factors involved in Th17 cell differentiation and metabolism. IC₅₀ values determined by luciferase reporter gene assays, employing constructs for either RORγ-Gal4 fusion proteins or full length receptors, were in the low micromolar range at around 2 µM. To highlight the functional consequences of this RORα/γ inverse agonism, we determined gene expression levels of important ROR target genes, i.e., IL-17A and glucose-6-phosphatase, in relevant cellular in vitro models of Jurkat T and HepG2 cells, respectively, by RT-qPCR (reverse transcription quantitative PCR). Thereby, it was shown that diosgenin leads to a dose-dependent decrease in target gene expressions consistent with its potent cellular ROR inverse agonistic activity. Additionally, in silico dockings of diosgenin to the ROR ligand-binding domain were performed to determine the underlying binding mode. Taken together, our results establish diosgenin as a novel, direct and dual-selective RORα/γ inverse agonist. This finding establishes a direct molecular target for diosgenin for the first time, which can further explain reported amendments in Th17-driven diseases by this compound.

The mechanism of dioscin preventing lung cancer based on network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea nipponica Makino as a Chinese folk medicine has been used for the treatment of chronic bronchitis, cough, and asthma. Several studies have established the antimetastatic potential of Dioscorea nipponica Makino extract. Dioscin is a major bioactive compound in Dioscorea nipponica Makino and has anti-tumor property in lung cancer cell lines. However, the preventive effect of dioscin against lung cancer and its key mechanism haven't been identified yet.

AIM OF STUDY

To identify the prevention effect of dioscin on lung cancer and explore its key mechanism based on network pharmacology and experimental validation.

METHODS

The potential targets of dioscin were obtained from the HERB database. The therapeutic targets of lung cancer were acquired from the GeneCards database. Protein-protein interaction network (PPI) was constructed in the STRING 11.0 database. The David database was used for enrichment analysis. Molecular Docking was finished by the AutoDock Vina. NSCLC cell lines and mouse lung cancer model were used to confirm the prevention effect of dioscin on lung cancer and its key mechanism.

RESULTS

76 potential targets of dioscin were identified to be involved in lung cancer treatment, which refer to 512 biological processes, 47 molecular functions, 77 cellular components and 107 signal pathways. The molecular docking suggested that dioscin might bind to AKT1, Caspase3, TP53, C-JUN and IL-6. The DARTS indicated that dioscin could bind to AKT1. In vitro, dioscin could decrease proliferation, invasion and migration in A549 and PC-9 cells with the significant reduction in the expression of p-AKT, MMP2, and PCNA. In vivo, dioscin could reduce lung nodules, lung injury, and mortality in mouse lung cancer model with reducing the expression of p-AKT, MMP2, PCNA and increasing the expression of active-caspase3.

CONCLUSION

Dioscin could prevent lung cancer and its key target is AKT1 kinase, a center protein of PI3K/AKT signaling pathway.

Computation-Based Discovery of Potential Targets for Rheumatoid Arthritis and Related Molecular Screening and Mechanism Analysis of Traditional Chinese Medicine

This study is aimed at screening potential therapeutic ingredients in traditional Chinese medicine (TCM) and identifying the key rheumatoid arthritis (RA) targets using computational simulations. Data for TCM-active ingredients with clear pharmacological effects were collected. Absorption, distribution, metabolism, excretion, and toxicity were evaluated. Potential RA targets were identified using the Gene Expression Omnibus (GEO) database, protein–protein interaction network, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and potential TCM ingredients using AutoDock Vina. To examine the mechanisms underlying small molecules, target prediction, Gene Ontology, KEGG, and network modeling analyses were conducted; the effects were verified in rat synovial cells using cell proliferation assay. The activities of tumor necrosis factor TNF-α and IL-1β and alterations in cellular target protein levels were detected by ELISA and Western blotting, respectively. In total, data for 432 TCM active ingredients with clear pharmacological effects were obtained. Five critical RA-related genes were identified; CCL5 and CXCL10 were selected for molecular docking. Target prediction and network-based proximity analysis showed that dioscin could modulate 22 known RA clinical targets. Dioscin, asiaticoside, and ginsenoside Re could effectively inhibit in vitro cell proliferation and secretion of TNF-α and IL-1β in RA rat synovial cells. Using bioinformatics and computer-aided drug design, the potential small anti-RA molecules and their mechanisms of action were comprehensively identified. Dioscin could significantly inhibit proliferation and induce apoptosis in RA rat synovial cells by reducing TNF-α and IL-1β secretion and inhibiting abnormal CCL5, CXCL10, CXCR2, and IL2 expression.

Effects of ginsenoside Rb1 on second-degree burn wound healing and FGF-2/PDGF-BB/PDGFR-β pathway modulation

Background

Panax notoginseng (Burk.) F. H. Chen (P. notoginseng) is a traditional Chinese medicine that has been used therapeutically for cardiovascular diseases, inflammatory diseases and traumatic injuries as well as for external and internal bleeding due to injury. Ginsenoside Rb1, a crucial monomeric active constituent extracted from P. notoginseng, has attracted widespread attention because of its potential anti-inflammatory, bacteriostatic, and cell growth-promoting effects. In this study, the therapeutic effects of ginsenoside Rb1 on second-degree burn in rats and the potential underlying mechanisms were explored.

Methods

A rat model of second-degree burn injury was established, and skin wound healing was monitored at different time points after ginsenoside Rb1 treatment. HE staining was performed to identify burn severity, and biological tissues were biopsied on days 0, 7, 14, and 24 after treatment. Skin wound healing at different time points was monitored by macroscopic observation. Furthermore, IHC, WB, and RT-PCR were utilized to determine the protein and mRNA expression levels of PDGF-BB, PDGFR-β, and FGF-2 in wound tissues after treatment.

Results

HE staining showed that after 24 days of ginsenoside Rb1 treatment, skin tissue morphology was significant improved. Macroscopic observation demonstrated that in ginsenoside Rb1-treated rats, the scab removal time and fur growth time were decreased, and the wound healing rate was increased. Collectively, the results of IHC, WB and RT-PCR showed that PDGF-BB, PDGFR-β, and FGF-2 expressions peaked earlier in ginsenoside Rb1-treated rats than in model rats, consistent with the macroscopic observations.

Conclusion

Collectively, these findings  indicated that ginsenoside Rb1 promotes burn wound healing via a mechanism possibly associated with upregulation of FGF-2/PDGF-BB/PDGFR-β gene and protein expressions.

Natural products as modulators of retinoic acid receptor-related orphan receptors (RORs)

Covering: 1994 to 2020 Retinoic acid receptor-related orphan receptors (RORs) belong to a subfamily of the nuclear receptor superfamily and possess prominent roles in circadian rhythm, metabolism, inflammation, and cancer. They have been subject of research for over two decades and represent attractive but challenging drug targets. Natural products were among the first identified ligands of RORs and continue to be of interest to this day. This review focuses on ligands and indirect modulators of RORs from natural sources and explores their roles in a therapeutic context.

Ginsenoside Rg3 Suppresses Epithelial-Mesenchymal Transition via Downregulating Notch-Hes1 Signaling in Colon Cancer Cells

Invasion and metastasis are the major causes leading to the high mortality of colon cancer. Ginsenoside Rg3 (Rg3), as a bioactive ginseng compound, is suggested to possess antimetastasis effects in colon cancer. However, the underlying molecular mechanisms remain unclear. In this study, we reported that Rg3 could effectively inhibit colon cancer cell invasion and metastasis through in vivo and in vitro studies. In addition, Rg3 suppressed the epithelial-mesenchymal transition (EMT) of HCT15 cells and SW48 cells evidenced by detecting EMT related markers E-cadherin, vimentin, and snail expression. Furthermore, inhibition of Notch signaling by LY411,575 or specific Hes1 siRNA obviously repressed colon cancer cell migration and metastasis, and induced increase in E-cadherin and decrease in vimentin and snail. Meanwhile, the expression of NICD and Hes1 was obviously decreased in the presence of Rg3. However, Rg3 failed to suppress EMT in Hes1 overexpressed colon cancer cells. In particular, Rg3 significantly reversed IL-6-induced EMT promotion and blocked IL-6- induced NICD and Hes1 upregulations. Overall, these findings suggested that Rg3 could inhibit colon cancer migration and metastasis via suppressing Notch-Hes1-EMT signaling.

Diosgenin Inhibits Excessive Proliferation and Inflammatory Response of Synovial Fibroblasts in Rheumatoid Arthritis by Targeting PDE3B

Rheumatoid arthritis (RA) is a chronic inflammation that can lead to loss of range of joint abnormalities in severe cases. Diosgenin has anti-inflammatory effects. This paper discussed the effect and mechanism of diosgenin on excessive proliferation and inflammatory response of synovial cells in RA. CCK-8 detected the cell viability, TUNEL assay detected the apoptosis of cells and western blot detected the expression of apoptosis-related proteins. Wound healing was used to detect cell migration and western blot detected the expression of migration-related proteins. ELISA kits were used to detect the levels of inflammatory cytokines in cells. Diosgenin can inhibit the proliferation and migration of RA synovial cells. At the same time, diosgenin could reduce the inflammatory response of RA synovial cells, during which the expression of PDE3B was significantly decreased. By overexpressing PDE3B, we found that diosgenin inhibited the proliferation, migration, and inflammatory response of RA synovial cells by downregulating PDE3B. Diosgenin can inhibit excessive proliferation and inflammatory response of synovial fibroblasts by targeting PDE3B.

Dioscorea nipponica Makino suppresses TPA-induced migration and invasion through inhibition of matrix metalloproteinase-9 in human cervical cancer cells

Dioscorea nipponica Makino has been used for the treatment of chronic bronchitis, rheumatoid arthritis, cough, and asthma. Several studies have established the antitumor effect of D. nipponica Makino extract (DNE). However, no investigations have considered the antimetastatic potential of DNE in cervical cancer cells. The present study examined the effects of DNE on cervical cancer cells treated with 12-O-tetradecanoylphorbol-13-acetate and characterized the possible molecular mechanisms. MTT assay results indicated that DNE exhibited very low cytotoxicity, and DNE significantly reduced the invasion and migration abilities of cervical cancer cells. Gelatin zymography analysis revealed that DNE significantly inhibited matrix metalloproteinase-9 (MMP-9) activity. Reverse transcription-polymerase chain reaction assay results revealed that DNE treatment inhibited the MMP-9 mRNA levels of HeLa and SiHa cells. Western blot results revealed that DNE significantly diminished the ERK1/2 phosphorylation. In conclusion, we revealed that the antimetastatic effects of DNE on cervical cancer cells are due to its inhibition of MMP-9 expression through the ERK1/2 pathway.

Diosgenin, a steroidal saponin, and its analogs: Effective therapies against different chronic diseases

BACKGROUND

Chronic diseases are a major cause of mortality worldwide, and despite the recent development in treatment modalities, synthetic drugs have continued to show toxic side effects and development of chemoresistance, thereby limiting their application. The use of phytochemicals has gained attention as they show minimal side effects. Diosgenin is one such phytochemical which has gained importance for its efficacy against the life-threatening diseases, such as cardiovascular diseases, cancer, nervous system disorders, asthma, arthritis, diabetes, and many more.

AIM

To evaluate the literature available on the potential of diosgenin and its analogs in modulating different molecular targets leading to the prevention and treatment of chronic diseases.

METHOD

A detailed literature search has been carried out on PubMed for gathering information related to the sources, biosynthesis, physicochemical properties, biological activities, pharmacokinetics, bioavailability and toxicity of diosgenin and its analogs.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and clinical trials that reported the efficacy of diosgenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK, etc., which play a crucial role in the development of most of the diseases. Reports have also revealed the safety of the compound and the adaptation of nanotechnological approaches for enhancing its bioavailability and pharmacokinetic properties.

SIGNIFICANCE

Thus, the review summarizes the efficacy of diosgenin and its analogs for developing as a potent drug against several chronic diseases.

Preventive effect of dioscin against monosodium urate-mediated gouty arthritis through inhibiting inflammasome NLRP3 and TLR4/NF-κB signaling pathway activation: an in vivo and in vitro study

Monosodium urate (MSU)-mediated inflammation is closely related to gouty arthritis (GA). Dioscin, an active ingredient, has been reported to possess anti-inflammatory property. Nevertheless, the role of dioscin in GA and the underlying mechanism have not been fully understood. In the present study, we investigated the anti-inflammatory effect of dioscin on MSU-induced GA through in vivo and in vitro experiments. Histopathological analysis showed that dioscin alleviated the severity of GA concomitant with the lowered uric acid and creatinine levels. Moreover, the increasing IL-1β, IL-6, and TNF-α levels induced by MSU were decreased via administration of dioscin in mice and human synoviocytes. Western blotting results suggested that dioscin inhibited the activation of NLRP3 through down-regulating the protein expressions of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved-caspase-1, as well as IL-1β. In addition, TLR4, myeloid differentiation primary response gene 88 (MyD88), p-IKKβ, p-p65, and NF-κB p65 in nuclei levels were significantly reduced by dioscin. Importantly, dioscin remarkably lowered the NF-κB p65-DNA activity in MSU-treated mice utilizing electrophoretic mobility shift assay (EMSA) analysis. Taken together, dioscin had a protective effect against MSU-initiated inflammatory response via repressing the production of inflammatory cytokines and the activation of inflammasome NLRP3 and TLR4/NF-κB signaling pathway. The above findings revealed that dioscin could be a potential drug for the treatment of GA.

The Role of Th17/Treg Axis in the Traditional Chinese Medicine Intervention on Immune-Mediated Inflammatory Diseases: A Systematic Review

The Th17/Treg axis plays a crucial role in immune-mediated inflammatory diseases (IMID) and might represent an interesting drug target of treatment strategy for these diseases. Accumulating evidence suggests a role for traditional Chinese medicine (TCM) in the modulation of Th17/Treg axis, but a comprehensive overview which summarizes this field hitherto is lacked. This paper performs a systematic literature review of the regulatory effects of TCM on the imbalance of Th17/Treg axis and its potential mechanisms. In addition, the frequency analysis and network pharmacology for the collected TCM herbs from clinical trial data were performed. The studies reported the changes in the ratio of Th17 and/or Treg cells as well as their transcription factor and related cytokines were included. Frequency analysis of composition of the 39 assessed TCM prescriptions showed that Astragalus membranaceus var.mongholicus (5.20%), Glycyrrhiza uralensis (3.67%), Paeonia obovate (3.06%), Salvia digitaloides (3.06%), and Angelica sinensis (2.75%) were the top five herbal components, which were closely associated to the treatment of IMID. Network pharmacology showed that six target proteins (transforming growth factor (TGF)-beta receptor type-1, TGF-beta receptor type-2, retineic-acid-receptor-related orphan nuclear receptor gamma (ROR-gamma), TGFB2, IL-17 and IL-2, respectively) might be involved in the regulatory effects of TCM on Th17/Treg axis. Moreover, there were nine active ingredients (including Oxymatrine, Baicalin, Triptolide, Paeoniflorin, Sinomenine, Celastrol, Emodin, Diosgenin and Chlorogenic acid) originating from TCM reported to have an immunological regulation effect on the Th17/Treg axis. The highlight of this systematic review is to reveal the pharmacological basis of TCM treating IMID and is helpful for supporting future pharmacologic-driven studies. Further research elucidates the immune-modulating mechanisms on Th17/Treg axis by TCM might provide a broader insight for the treatment of IMID.

Anti-rheumatoid arthritis effects of flavonoids from Daphne genkwa

OBJECTIVE

This study aims to select the most effective anti-Rheumatoid Arthritis (RA) component of flavonoids from Daphne genkwa Sieb. et Zucc. by anti-inflammatory and immunomodulatory effects in vitro, and to elucidate the mechanism.

METHODS

The anti-inflammatory and immunomodulatory effects of total flavonoids (TF) and four flavonoid components (genkwanin, hydroxygenkwanin, luteolin and apigenin) were determined by pharmacological approach in LPS-induced RAW 264.7 macrophages and ConA-induced T lymphocytes. Principal component analysis (PCA) was used to obtain the optimal anti-RA component in vitro. Western blot and real-time quantitative PCR (q-PCR) were used to explore the mechanisms. Finally, the in vitro anti-RA effect was verified by human rheumatoid arthritis fibroblast-like synoviocytes (FLSs).

RESULTS

TF and four flavonoids significantly reduced the expressions of NO, iNOS, TNF-α, IL-6, IFN-γ and IL-2. PCA showed that genkwanin was the most effective anti-RA component in vitro. Genkwanin inhibited nuclear factor-κB (NF-κB) pathway by decreasing the phosphorylation levels of IKK, IκB and NF-κB, and down-regulated the expressions of iNOS, COX-2 and IL-6 mRNA. Genkwanin also inhibited the abnormal proliferation of FLSs and down-regulated the secretions of NO and IL-6.

CONCLUSION

The most effective anti-RA component was genkwanin. Genkwanin exerts anti-RA effect through down-regulating the activation of NF-κB pathway and mRNA expressions of inflammatory mediators, and also by inhibiting the abnormal proliferation of FLSs and its NO and IL-6 secretion levels.

Identification of the metabolites in normal and AA rat plasma, urine and feces after oral administration of Daphne genkwa flavonoids by LC-Q-TOF-MS spectrometry

Daphne genkwa Sieb. et Zucc., as a traditional oriental herb, has been widely distributed and employed in China. The major bioactive components in D. genkwa are flavonoid compounds, which showed pharmacological activities such as anti-inflammatory, analgesic, anti-tumor and immunomodulatory activities. In this study, we analyzed total flavonoids in D. genkwa and their metabolites in normal and adjuvant arthritis (AA) rat plasma, urine and feces samples by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). A total of 4 metabolites in plasma, 9 metabolites in urine and 15 metabolites in feces were characterized respectively by LC-Q-TOF-MS technology in normal rat. And 9 of the metabolites were observed in the AA rat urine, while there was no prototype drug or its metabolites detected in plasma and fecal samples. The metabolic pathway mainly involves hydroxylation, methylation, glucuronide, sulfate conjugation, oxidation and reduction, during the phase I and phase II biotransformation pathway. All the information gained here will be greatly helpful in elucidating the potential biological and pharmacological mechanism of flavonoid in D. genkwa, thus providing new ideas for drug development.