Total glucosides of paeony inhibits Th1/Th17 cells via decreasing dendritic cells activation in rheumatoid arthritis

Integrating 16srRNA sequencing, non-targeted metabolomics, and transcriptome sequencing to explore the mechanism of Total glucosides of paeony alleviating ulcerative colitis

Total glucosides of paeony (TGP), an active ingredient extracted from the dried root of Paeonia lactiflora Pall., has been approved in China for the treatment of various autoimmune diseases. However, the role and mechanism of TGP in UC have yet to be fully elucidated. This study aims to investigate the regulatory effects and underlying mechanisms of TGP on intestinal homeostasis disruption and immune imbalance in a mouse model of dextran sulfate sodium (DSS)-induced colitis. The results showed that TGP alleviated DSS induced body weight loss, colonic shortening and histopathological changes in mice, and also enhanced the integrity of the intestinal barrier by up-regulating the expression of ZO-1, Occludin and tight junction protein in the colon. The results of 16S and antibiotic cocktail (ABX) experiments showed that TGP alleviated colitis by inhibiting Th17 cell differentiation by correcting intestinal microbial imbalance in UC mice. Mechanism studies showed that TGP inhibited the activation of JAK2/STAT3 signaling pathway in UC mice, and decreased the levels of inflammatory factors in colon supernatant and serum. Importantly, TGP regulates JAK2/STAT3 to inhibit Th17 cell differentiation depending on gut flora. In addition, TGP can also improve the metabolic imbalance in UC mice, especially purine metabolism. In conclusion, TGP promotes the normalization of purine metabolism and relies on gut microbiota to regulate JAK2/STAT3 pathway, inhibit Th17 cell differentiation, and alleviate colitis. Our findings highlight TGP as a promising treatment candidate for ulcerative colitis.

Variable innate lymphoid cells predominancy in oral lichen planus latently led to diverse clinical outcomes: a proof-of-concept study

Objectives

To search for a new classification scheme for oral lichen planus (OLP) and oral lichenoid lesions (OLL) based on innate lymphoid cells (ILCs) and to evaluate the clinical significance of this classification for diagnosis and treatment.

Subjects and methods

This study was based on a clinical cohort and applied flow cytometry to prospectively analyze the ILC subgroups and proportions in OLP and OLL lesions using SPSS software (version 26.0) to attempt cluster analysis to classify diseases at the cellular level based on the phenotype and quantity of ILCs cells, analyze the correlation between the new classification of diseases and clinical risk factors based on the patient's clinical background information and classification results, and evaluate the differences in therapeutic effects among patients in different groups in corresponding clinical cohorts.

Results

In the OLP and OLL groups, the ILC compartment consisted mainly of ILC1 (75.02% ± 27.55% and 72.99% ± 25.23%, respectively), ILC2 (1.49% ± 4.12% and 1.72% ± 3.18%, respectively), and ILC3 (16.52% ± 19.47% and 18.77% ± 18.12%, respectively). Using k-means clustering and two-step clustering, patients could be clustered into three groups that did not respond equally to the same treatment. Using k-means clustering, there was a statistically significant difference in REU scores between the ILC1 advantage group and the OLL subgroup before and after treatment (P = 0.02), which was not observed in two-step clustering. This indicates that k-means clustering may have greater value in the clinical application of OLL. In the ILC1 absolute advantage group, using HCQ + TGP for one month could effectively treat the patients regardless of the use of k-means clustering or two-step clustering (P ≤0.001), whereas the other groups did not.

Conclusions

This study provides a preliminary OLP and OLL classification method based on ILC subgroups that can guide the cytological classification of diseases to a certain extent. Further clinical application values should be verified in subsequent cohort studies.

Identification and validation of hub m7G-related genes and infiltrating immune cells in osteoarthritis based on integrated computational and bioinformatics analysis

BACKGROUND

Osteoarthritis (OA) is a joint disease closely associated with synovial tissue inflammation, with the severity of synovitis impacting disease progression. m7G RNA methylation is critical in RNA processing, metabolism, and function, but its role in OA synovial tissue is not well understood. This study explores the relationship between m7G methylation and immune infiltration in OA.

METHODS

Data were obtained from the GEO database. Hub genes related to m7G were identified using differential expression and LASSO-Cox regression analysis, and a diagnostic model was developed. Functional enrichment, drug target prediction, and target gene-related miRNA prediction were performed for these genes. Immune cell infiltration was analyzed using the CIBERSORT algorithm, and unsupervised clustering analysis was conducted to examine immune infiltration patterns. RT-qPCR was used to validate hub gene expression.

RESULTS

Seven m7G hub genes (SNUPN, RNMT, NUDT1, LSM1, LARP1, CYFIP2, and CYFIP1) were identified and used to develop a nomogram for OA risk prediction. Functional enrichment indicated involvement in mRNA metabolism and RNA transport. Differences in macrophage and T-cell infiltration were observed between OA and normal groups. Two distinct m7G immune infiltration patterns were identified, with significant microenvironment differences between clusters. RT-qPCR confirmed differential hub gene expression.

CONCLUSION

A diagnostic model based on seven m7G hub genes was developed, highlighting these genes as potential biomarkers and significant players in OA pathogenesis.

The immunoregulatory effects of total glucosides of peony in autoimmune diseases

Total glucoside of peony and its main active ingredient paeoniflorin, extracted from the Chinese herb Paeonia lactiflora Pallas, exhibit potent immunomodulatory effects. Total glucoside of peony has been shown to inhibit inflammatory responses and disease progression in experimental models of multiple autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, psoriasis, and so on. Total glucoside of peony shows broad immunomodulatory effects on many immune cells, such as T cells, macrophages, and dendritic cells, by regulating their activation, proliferation, differentiation, and production of effector molecules. Mechanistically, total glucoside of peony modulates intracellular signaling transductions, including JAK/STAT, NF-κB, MAPK, and PI3K/AKT/mTOR pathways. Moreover, total glucoside of peony has been applied in the clinical treatment of various autoimmune diseases with satisfactory therapeutic outcomes and minor side effects. Thus, available studies have demonstrated that total glucoside of peony and its bioactive constituents exhibit anti-inflammatory and immunomodulatory functions and may have extensive applications in the treatment of autoimmune diseases.

Chinese Herbal Medicine and Their Active Ingredients Involved in the Treatment of Atopic Dermatitis Related Signaling Pathways

Atopic dermatitis (AD) is a common inflammatory dermatitis of the skin and poses therapeutic challenges due to the adverse reactions and high costs associated with available treatments. In Eastern Asian countries, a plethora of herbal remedies is extensively employed for the alleviation of AD. Many of these botanicals are renowned for their formidable anti-inflammatory properties, contributing to AD management. Chinese herbal medicine (CHM) and its active ingredients exhibit both prophylactic and therapeutic promise against AD by modulating inflammatory response, orchestrating immune system functions, and enhancing antioxidant activities. A comprehensive exploration of the underlying mechanisms involved in CHM treatment can enhance the comprehension of AD pathogenesis and facilitate the development of innovative drugs for AD. This study aims to elucidate the signaling pathways and potential targets implicated in CHM-based treatment of AD, providing a systematic theoretical framework for its application in therapy while serving as a valuable reference for developing more effective and safer AD therapeutic agents.

Therapeutic potential and pharmacological insights of total glucosides of paeony in dermatologic diseases: a comprehensive review

Total glucosides of paeony (TGP) are a group of monoterpenes extracted from Paeonia lactiflora Pall., primarily including metabolites such as paeoniflorin and oxypaeoniflorin. Modern pharmacological studies have shown that TGP possesses a variety of biological effects, including immunomodulatory, anti-inflammatory, hepatoprotective, nephroprotective, antidepressant, and cell proliferation regulatory activities. In recent years, clinical research has demonstrated favorable therapeutic effects of TGP on disorders of the liver, cardiovascular, nervous, endocrine, and skeletal systems. Particularly in dermatological treatments, TGP has been found to significantly improve clinical symptoms and shorten the course of the disease. However, there are still certain limitations in the scientific rigor of existing studies and in its clinical application. To assess the potential of TGP in treating dermatologic diseases, this article provides a review of its botanical sources, preparation and extraction processes, quality control, and major chemical metabolites, as well as its pharmacological research and clinical applications in dermatology. Additionally, the mechanisms of action, research gaps, and future directions for TGP in the treatment of dermatologic diseases are discussed, offering valuable guidance for future clinical research on TGP in dermatology.

Gut microbiota in pre-clinical rheumatoid arthritis: From pathogenesis to preventing progression

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive polyarthritis that leads to cartilage and bone damage. Pre-clinical RA is a prolonged state before clinical arthritis and RA develop, in which autoantibodies (antibodies against citrullinated proteins, rheumatoid factors) can be present due to the breakdown of immunologic self-tolerance. As early treatment initiation before the onset of polyarthritis may achieve sustained remission, optimize clinical outcomes, and even prevent RA progression, the pre-clinical RA stage is showing the prospect to be the window of opportunity for RA treatment. Growing evidence has shown the role of the gut microbiota in inducing systemic inflammation and polyarthritis via multiple mechanisms, which may involve molecular mimicry, impaired intestinal barrier function, gut microbiota-derived metabolites mediated immune regulation, modulation of the gut microbiota's effect on immune cells, intestinal epithelial cells autophagy, and the interaction between the microbiome and human leukocyte antigen alleles as well as microRNAs. Since gut microbiota alterations in pre-clinical RA have been reported, potential therapies for modifying the gut microbiota in pre-clinical RA, including natural products, antibiotic therapy, fecal microbiota transplantation, probiotics, microRNAs therapy, vitamin D supplementation, autophagy inducer-based treatment, prebiotics, and diet, holds great promise for the successful treatment and even prevention of RA via altering ongoing inflammation. In this review, we summarized current studies that include pathogenesis of gut microbiota in RA progression and promising therapeutic strategies to provide novel ideas for the management of pre-clinical RA and possibly preventing arthritis progression.

Efficacy and safety of total glucosides of paeony in the treatment of 5 types of inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

To evaluate efficacy and safety of total glucosides of paeony in the treatment of 5 types of inflammatory arthritis METHODS: Databases such as Pubmed, Cochran Library, Embase were searched to collect RCTs about TGP in the treatment of inflammatory arthritis. Then, the RCTs were assessed for risk of bias and RCT data were extracted. Finally, RevMan 5.4 was used for the meta-analysis.

RESULTS

A total of 63 RCTs were finally included, involving 5293 participants and 5 types of types of inflammatory arthritis: rheumatoid arthritis (RA), ankylosing spondylitis (AS), osteoarthritis (OA), juvenile idiopathic arthritis (JIA), psoriatic arthritis. For AS, TGP may improve AS disease activity score (ASDAS), decrease erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tumor necrosis factor (TNF)- α and interleukin (IL)- 6; for RA, TGP may improve disease activity of 28 joints (DAS28), decrease ESR, CRP, rheumatoid factor (RF), TNF-α and IL-6; for psoriatic arthritis, TGP may improve psoriasis area and severity index (PASI) and decrease ESR; for OA, TGP may improve visual analogue scale (VAS) and decrease nitric oxide (NO); for JIA, TGP may increase total efficiency rate, decrease ESR, CRP and TNF-α. For safety, RCTs showed that the addition of TGP did not increase adverse events, and may even reduce adverse events.

CONCLUSION

TGP may improve symptoms and inflammation levels in patients with inflammatory arthritis. However, due to the low quality and small number of RCTs, large-sample, multi-center clinical trials are still needed for revision or validation.

Regulation of Myeloid Dendritic Cells by Synthetic and Natural Compounds for the Treatment of Rheumatoid Arthritis

Different subsets of dendritic cells (DCs) participate in the development of rheumatoid arthritis (RA). In particular, myeloid DCs play a key role in the generation of autoreactive T and B cells. Herein, we undertook a literature review on those synthetic and natural compounds that have therapeutic efficacy/potential for RA and act through the regulation of myeloid DCs. Most of these compounds inhibit both the maturation of DCs and their secretion of inflammatory cytokines and, subsequently, alter the downstream T-cell response (suppression of Th1 and Th17 responses while expanding the Treg response). The majority of the synthetic compounds are approved for the treatment of patients with RA, which is consistent with the importance of DCs in the pathogenesis of RA. All of the natural compounds are derived from plants. Their DC-modulating effect has been demonstrated both in vitro and in vivo. In addition, these natural products ameliorate arthritis in rodents and are potential therapeutics for human RA.

Paeoniflorin drives the immunomodulatory effects of mesenchymal stem cells by regulating Th1/Th2 cytokines in oral lichen planus

Lichen planus (LP) is a chronic inflammatory disease. Oral lichen planus (OLP) mainly appears as oral mucosal reticular or ulcerative lesions with an unknown etiology. We aimed to explore the immunomodulatory effect of paeoniflorin (PF) in mesenchymal stem cells (MSCs) and the potential involvement of Th1/Th2 cytokines in OLP. The effects of paeoniflorin on the proliferation and migration of MSCs were detected by Cell Counting Kit-8 (CCK8) and Transwell assays. MSCs were subjected to osteogenic, adipogenic and neurogenic induction followed by Alizarin red, oil red O, real-time PCR and immunofluorescence assays. We found that paeoniflorin promoted the proliferation, migration and multilineage differentiation of MSCs from OLP lesions (OLP-MSCs) in vitro. Paeoniflorin pretreatment increased the inhibitory effect of OLP-MSCs on peripheral blood mononuclear cells. Furthermore, paeoniflorin-pretreated OLP-MSCs simultaneously decreased Th1 cytokine levels and increased Th2 cytokine levels in T lymphocyte cocultures. Finally, paeoniflorin-pretreated OLP-MSCs also promoted the Th1/Th2 balance both in vitro and in the serum of mice that received skin allografts. In conclusion, paeoniflorin enhanced MSC immunomodulation and changed the inflammatory microenvironment via T lymphocytes, suggesting that the improvement of OLP-MSCs is a promising therapeutic approach for OLP.

High-Throughput Metabolomics Integrated Network Pharmacology Reveals the Underlying Mechanism of Paeoniae Radix Alba Treating Rheumatoid Arthritis

Objective: The mechanism of action and potential targets of Paeoniae RadixAlba (Baishao, B) in the treatment of adjuvant-induced arthritis (AIA) rats are explained using metabolomics and network pharmacology techniques, and the research evidence for the development of anti-rheumatoid arthritis (RA) drugs is enriched. Methods: The rats were injected with Freund’s complete adjuvant (CFA) to induce arthritis. We then measured the general physical characteristics, examined their X-rays and histopathology to evaluate the pathological condition of the inflammation models, and conducted metabolomics studies on the change in urine metabolism caused by CFA. The lyophilized powder of B at a dose of 2.16 g/kg was orally administered to the rats continuously for 28 days, and the therapeutic effect was evaluated. Network pharmacology prediction shows that B contains the target action of the ingredient, and the simulation of the target molecular docking, in combination with the metabolomics analysis results, shows that B has a potential role in the treatment of AIA rats. Results: B can reduce the paw swelling and pathological changes in rats caused by CFA, reverse the levels of 12 urine biomarkers, and regulate histidine metabolism, phenylalanine metabolism, arginine, proline metabolism, pyrimidine metabolism, etc. The prediction of the active ingredient target in B indicates that it may act as an inflammatory signaling pathway in anti-RA, among them being paeoniflorin, palbinone, beta-sitosterol, kaempferol, and catechin, which are the significant active ingredients. Conclusion: The metabolomics results revealed the markers and metabolic mechanisms of urinary metabolic disorders in rats with AIA, demonstrated the efficacy of the therapeutic effect of B, and identified the key ingredients in B, providing theoretical support for the subsequent development and utilization of B.

Total glucosides of paeony inhibit breast cancer growth by inhibiting TAMs infiltration through NF-κB/CCL2 signaling

PURPOSE

The high density of tumor-associated macrophages (TAMs) and inflammatory factors are crucial elements leading to tumor immune tolerance. Previously, we found that total glucosides of paeony (TGP) have strong inhibitory effects on the release of various inflammatory factors; however, it is unclear whether the inhibitory effects can improve the inflammatory microenvironment of tumors. Therefore, in the present study, we investigated the mechanism via which TGP depresses tumor growth and metastasis via modulation of TAM infiltration in breast cancer.

METHODS

We assessed the effects of TGP on various mouse models of tumor. Lung metastasis was detected using hematoxylin and eosin staining. T cell (CD3⁺CD4⁺ and CD3⁺CD8⁺) effector and memory subsets, and TAM (CD45⁺CD11b⁺F4/80⁺) populations in the tumor microenvironment (TME) were examined using flow cytometry. Lipopolysaccharide (LPS)-stimulated macrophage experiments were used to investigate the TGP anti-inflammatory effects in vitro. Furthermore, conditional medium (CM) was added to detect 4T1 breast cancer cell growth using a Real-Time Cell Analyzer (RTCA) xCELLigence system. Inflammatory cytokine and chemokine levels were measured using cytometric bead array (CBA) kits and quantitative polymerase chain reaction (qPCR). NF-κB expression in the nucleus was examined by immunofluorescence and Western blot analysis.

RESULTS

TGP suppressed tumor growth and lung metastasis, decreased CD45⁺CD11b⁺F4/80⁺ (TAMs) population obviously, and increased CD44^LowCD62L^Hi (T memory stem cells) and CD44^HiCD62L^Hi (central memory cells) populations in the tumor-infiltrating CD4⁺ and CD8⁺ T cells. In addition, TGP reduced inflammatory factor levels in tumors, thus inhibiting the infiltration of TAMs to improve the inflammation immunosuppressive microenvironment. In the in vitro experiment, TGP inhibited IL-10 and C-C Motif Chemokine Ligand 2 (CCL2) secretion and mRNA expression in LPS-stimulated macrophages to inhibit 4T1 cell growth and restrain macrophages M2 polarization. In addition, TGP can directly inhibit 4T1 cell proliferation by restraining autocrine CCL2 and IL-10. Further mechanistic studies reavealed that TGP inhibited CCL2 secretion by inhibiting NF-κB accumulation in the nucleus in macrophages.

CONCLUSION

TGP reduced TAM recruitment mainly through the NF-κB/CCL2 signaling pathway, thereby promoting T cell infiltration in the TME. TGP has a unique advantage in balancing the inflammatory response. Furthermore, our results present novel insights on the mechanisms underlying TAM infiltration that were inhibited by TGP, with potential application in development of novel therapies targeting CCL2 pathways.

Total glucosides of paeony ameliorates oxidative stress, apoptosis and inflammatory response by regulating the Smad7‑TGF‑β pathway in allergic rhinitis

Total glucosides of paeony (TGP), an active ingredient extracted from the root of Paeonia alba, has been reported to display an anti-inflammatory effect. However, the effect of TGP on allergic rhinitis (AR) is still unknown. The present study aimed to assess the role of TGP in an AR mouse model. An AR mouse model was established using the ovalbumin method. The expression levels of Smad7/TGF-β pathway-related prtoeins in nasal mucosa tissues were determined by immunofluorescence, immunohistochemistry and western blotting. The severity of nasal allergic symptoms was detected by recording the frequency of sneezing and nose rubbing motions in all mice for 20 min. The levels of IgE and inflammatory cytokines, including IL-4, IL-5, IL-17 and IFN-γ, in the serum were measured by conducting ELISAs. H&E staining, periodic acid-Schiff staining and Masson staining were used to detected histopathological changes in mice. The concentrations of malondialdehyde and glutathione, and the activities of superoxide dismutase and catalase in tissue supernatant and serum were quantified using commercial assay kits. Apoptosis of nasal tissue cells was detected by performing TUNEL assays and western blotting. The expression of Smad7 was upregulated and that of TGF-β was downregulated in the nasal tissue of AR mice. Additionally, TGP regulated the Smad7/TGF-β pathway in the nasal tissue of AR mice. TGP alleviated serum IgE, nasal symptoms and histopathological changes in AR mice. Moreover, TGP ameliorated oxidative stress, cell apoptosis and inflammatory response. Smad7 small interfering RNA intervention aggravated the symptoms of AR mice via activation of the TGF-β pathway and reversed the protective effect of TGP in AR mice. TGP ameliorated oxidative stress, apoptosis and inflammatory response via the Smad7/TGF-β pathway in AR.

Clinical safety of total glucosides of paeony adjuvant therapy for rheumatoid arthritis treatment: a systematic review and meta-analysis

BACKGROUND

Total glucosides of paeony (TGP), an active compound extracted from the roots of Paeonia lactiflora Pallas, has been increasingly used as the adjunctive therapy for rheumatoid arthritis (RA) patients. Though TGP could mitigate the unanticipated adverse effects during the conventional treatment of RA, high-quality evidence-based meta-analysis data on this subject are still insufficient. The objective of this study is to evaluate the clinical safety of TGP adjuvant therapy in the RA treatment.

METHODS

PubMed, EMBASE, Web of Science, China Network Knowledge Infrastructure (CNKI), SinoMed and WanFang Data were retrieved for randomized controlled trials (RCTs) and cohort study about TGP adjuvant therapy in patients with RA up to 28 January 2021. Literatures with eligibility criteria and information were screened and extracted by two researchers independently. The RevMan5.3 software was used for data analysis with effect estimates as risk ratio (RR) with 95% confidence interval (CI).

RESULTS

A total of 39 studies involving 3680 RA participants were included. There were 8 comparisons: TGP plus methotrexate (MTX) therapy versus MTX therapy, TGP plus leflunomide (LEF) therapy versus LEF therapy, TGP plus MTX and LEF therapy versus MTX plus LEF therapy, TGP plus tripterygium glycosides (TG) therapy versus TG therapy, TGP plus meloxicam (MLX) therapy versus MLX therapy and TGP plus sulfasalazine (SSZ) therapy versus SSZ therapy, TGP plus iguratimod (IGU) therapy versus IGU therapy, TGP plus prednisone acetate tablets (PAT) therapy versus PAT therapy. The meta-analysis results showed that the occurrence of hepatic adverse effect (RR = 0.31, 95% CI = 0.23-0.41, P < 0.00001) and leukopenia (RR = 0.41, 95% CI = 0.26-0.66, P = 0.0002) in TGP adjuvant therapy was significant decreased compared with non-TGP therapy. However, only TGP plus LEF therapy (RR = 0.22, 95% CI = 0.08-0.60, P = 0.003) and TGP plus MTX and LEF therapy (RR = 0.31, 95% CI = 0.22-0.42, P < 0.00001) had statistical difference in the subgroups of hepatic adverse effect. In leukopenia, TGP plus MTX and LEF therapy (RR = 0.47, 95% CI = 0.25-0.87, P = 0.02) had statistical difference.

CONCLUSIONS

This meta-analysis indicated that TGP adjuvant therapy might alleviate the incidence of hepatic adverse effect and leukopenia for the RA treatment compared to non-TGP therapy. The clinical safety of TGP adjuvant therapy warrant further investigation in experimental studies.

Natural Plant Extracts and Compounds for Rheumatoid Arthritis Therapy

Natural plant extracts and compounds (NPECs), which originate from herbs or plants, have been used in the clinical treatment of rheumatoid arthritis (RA) for many years. Over the years, many scientists have carried out a series of studies on the treatment of RA by NPEC. They found a high quantity of active NPECs with broad application prospects. In view of various complex functions of these NPECs, exploring their potential as medicines for RA treatment will be beneficial for RA patients. Thus, to help advance the development of high-quality NPECs for RA, we herein aimed to review the research progress of NPECs in the treatment of RA in recent years. Our findings showed that, from the pharmacological perspective, natural plant extracts or mixed herbal compounds effectively regulate the immune system to alleviate RA by inhibiting pro-inflammatory cytokines. Further, individualized medication can be applied according to each patient's physical condition. However, the pathogenesis of RA and its immune mechanism has not been fully understood and requires further studies.

Total glucosides of paeony: A review of its phytochemistry, role in autoimmune diseases, and mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniae Radix Alba (PRA, called baishao in China), the root of Paeonia lactiflora Pall., has shown a rich medicinal value for more than 2000 years. PRA is used in local medicine and traditional medicine for autoimmune diseases associated with inflammation. At present, total glucosides of paeony (TGP), the main active ingredient of PRA, has been developed into a preparation for the treatment of autoimmune diseases, as TGP exhibits the effect of regulating immunity, anti-inflammatory, and analgesic effects.

AIM OF THE REVIEW

TGP was developed and applied to inflammation-related autoimmune diseases in modern clinical practice. Based on its application in traditional prescriptions, this article reviews PRA's botany and phytochemistry (including its extraction process and quality control), and discusses the clinical application and pharmacological research of TGP as an anti-inflammatory drug from the perspective of ethnopharmacology. Additionally, we review modern pharmacological and molecular-target research on TGP and discuss the mechanisms of TGP in treating autoimmune diseases. Through a systematic literature review, we also highlight the clinical efficacy of TGP in the treatment of immune diseases, and provide a reference for the continued scientific development and quality control of TGP so that its wider application and clinical value can be fully realized.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Total glucosides of paeony", "Paeonia lactiflora Pall. ", "Paeonia veitchii Lynch", "Paeoniae Radix Alba or white peony", "Paeoniae Radix Rubra or red peony", "Paeoniflorin", "Albiflorin", "Autoimmune diseases", and their combinations. In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

Approximately 15 compounds have been identified in TGP, of which paeoniflorin and albiflorin are the most common constituents. In recent years, studies have found that TGP and its main chemical components are effective in the treatment of autoimmune diseases, such as rheumatoid arthritis, psoriasis, oral lichen planus, and Sjogren's syndrome. TGP has a variety of pharmacological effects related to PRA traditional effects, including anti-organ-damage, anti-inflammatory, analgesic, antioxidant, cardiovascular, and nervous-system protection. Previously published reports on TGP treatment of autoimmune diseases have shown that TGP regulates intracellular pathways, such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathways. However, there is no standardized preparation method for TGP, and there is insufficient quality control of formulations. Many related pharmacological studies have not tested TGP components, and the validity of such pharmacological results requires further verification.

CONCLUSIONS

Modern pharmacological research on TGP is based on the traditional usage of PRA, and its folk medicinal value in the treatment of autoimmune diseases has now been verified. In particular, TGP has been developed into a formulation used clinically for the treatment of autoimmune diseases. The combination of TGP capsules and chemicals to treat autoimmune diseases has the effect of increasing efficacy and reducing toxicity. Based on further research on its preparation, quality control, and mechanisms of action, TGP is expected to eventually play a greater role in the treatment of autoimmune diseases.

Efficacy, Chemical Constituents, and Pharmacological Actions of Radix Paeoniae Rubra and Radix Paeoniae Alba

Radix Paeoniae Rubra and Radix Paeoniae Alba are the different characteristic forms of Paeonia lactiflora Pall. They are widely used as traditional Chinese medicines in clinical practices. This study analyzes the development history, efficacy, chemical compositions, and pharmacological effects of Radix Paeoniae Rubra and Radix Paeoniae Alba, and explores the causes of the similarities and differences of these two amalgams. It provides a basis for the clinical application of these two Chinese medicinal materials, and lays a foundation for further study of the pharmacological effects and the quality identification of Paeonia lactiflora Pall as it applies to traditional Chinese medicine.

Chinese Herbal Medicines for Rheumatoid Arthritis: Text-Mining the Classical Literature for Potentially Effective Natural Products

Background

Rheumatoid arthritis (RA) is an autoimmune disease characterized by multijoint swelling, pain, and destruction of the synovial joints. Treatments are available but new therapies are still required. One source of new therapies is natural products, including herbs used in traditional medicines. In China and neighbouring countries, natural products have been used throughout recorded history and are still in use for RA and its symptoms. This study used text-mining of a database of classical Chinese medical books to identify candidates for future clinical and experimental investigations of therapeutics for RA.

Methods

The database Encyclopaedia of Traditional Chinese Medicine (Zhong Hua Yi Dian) includes the full texts of over 1,150 classical books. Eight traditional terms were searched. All citations were assessed for relevance to RA. Results and Conclusions. After removal of duplications, 3,174 citations were considered. After applying the exclusion and inclusion criteria, 548 citations of traditional formulas were included. These derived from 138 books written from 206 CE to 1948. These formulas included 5,018 ingredients (mean, 9 ingredients/formula) comprising 243 different natural products. When these text-mining results were compared to the 18 formulas recommended in a modern Chinese Medicine clinical practice guideline, 44% of the herbal formulas were the same. This suggests considerable continuity in the clinical application of these herbs between classical and modern Chinese medicine practice. Of the 15 herbs most frequently used as ingredients of the classical formulas, all have received research attention, and all have been reported to have anti-inflammatory effects. Two of these 15 herbs have already been developed into new anti-RA therapeutics—sinomenine from Sinomenium acutum (Thunb.) Rehd. & Wils and total glucosides of peony from Paeonia lactiflora Pall. Nevertheless, there remains considerable scope for further research. This text-mining approach was effective in identifying multiple natural product candidates for future research.

[Total glucosides of paeony inhibits proliferation and promotes activation- induced cell death of mouse T cells in vitro]

OBJECTIVE

To investigate the effects of total glucosides of paeony (TGP) on the proliferation and activation-induced cell death of mouse T cells and the mechanism underlying the immunosuppressive effects of TGP.

METHODS

Purified total T cells isolated from the spleen of C57BL/6 mice were treated with TGP at 0, 50, 100, or 200 μg/mL and stimulated by anti-CD3/ CD28. Flow cytometry was performed to detect the cell death and the proliferation of CFSE-labeled T cells. The expression of Fas/FasL mRNA was detected using RT-PCR, and flow cytometry was used to analyze the expression of Fas/FasL proteins on activated T cells. Western blotting was used to detect the expression of Bcl-2 in the cells.

RESULTS

TGP treatment for 48 h significantly reduced the total number and percentage of viable T cells and dose-dependently lowered the percentage of divided T cells. TGP treatment obviously up-regulated the cellular expression of Fas mRNA, enhanced Fas expression on the surface of the T cells, and decreased the expression level of Bcl-2 protein in the cells.

CONCLUSIONS

TGP significantly inhibits proliferation and promotes activation-induced cell death of mouse T cell by increasing the expression of Fas and downregulating the expression of Bcl-2.

Anti-inflammatory and immunoregulatory effects of paeoniflorin and total glucosides of paeony

As a Traditional Chinese Medicine, Paeonia lactiflora Pallas has been used to treat pain, inflammation and immune disorders for more than 1000 years in China. Total glycoside of paeony (TGP) is extracted from the dried root of Paeonia lactiflora Pallas. Paeoniflorin (Pae) is the major active component of TGP. Our research group has done a lot of work in the pharmacological mechanisms of Pae and found that Pae possessed extensive anti-inflammatory and immune regulatory effects. Pae could inhibit inflammation in the animal models of autoimmune diseases, such as experimental arthritis, psoriatic mice and experimental autoimmune encephalomyelitis, and so on. Pae modulates the functions and activation of immune cells, decreases inflammatory medium production, and restores abnormal signal pathway. Pae could balance the subsets of immune cells through inhibiting abnormal activated cell subsets and restoring regulatory cell subsets. Pae could regulate signaling pathways (GPCR pathway, MAPKs /NF-κB patway, PI3K /Akt /mTOR pathway, JAK2 /STAT3 pathway, TGFβ /Smads, and etc.). TGP is composed of Pae, hydroxyl-paeoniflorin, paeonin, albiflorin and benzoylpaeoniflorin etc. Pae accounts for more than 40% of TGP. Like Pae, TGP has anti-inflammatory and immune regulatory effects. TGP has been widely used to treat autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, allergic contact dermatitis, and etc. in China. Furthermore, TGP has some superior features with immune regulation, gentle effect, many indications and few adverse drug reactions. These findings suggest that TGP may be a promising anti-inflammatory and immune drug with soft regulation and has more superiority in the treatment of AIDs. Currently, TGP is used for the treatment of RA, SLE and other AIDs in more than 1000 hospitals in China, which obtained great social and economic benefits.

Total Glucosides of Paeony protects against collagen-induced mouse arthritis via inhibiting follicular helper T cell differentiation

BACKGROUND

The development of rheumatoid arthritis (RA) is related to germinal center (GC) response and autoreactive T cells, which mediate adaptive immunity and play an important role in stimulating the production of autoantibodies and pro-inflammatory cytokines by B cells and macrophages. Total Glucosides of Paeony (TGP) has anti-inflammatory, immunomodulatory and analgesic effects and is widely used to treat RA. However, few studies investigated whether the therapeutic effect of TGP is associated with the inhibition of autoimmune response.

PURPOSE

The aim of this study was to investigate the effects and mechanisms of TGP on RA.

STUDY DESIGN

Type II collagen-induced arthritis (CIA) mouse model was used, and TGP and paeoniflorin were intragastrically treated.

METHODS

DBA/1 mice were divided into 5 groups: control, model, positive drug (paeoniflorin) and high- and low-dose TGP group. After 21 days of intragastric administration, the pathological change, inflammation expression and molecular mechanism of each group of mice were detected by Micro-CT, histochemical analysis, ELLSA, Western blot, RT-qPCR and flow cytometry.

RESULTS

Our study found that TGP treatment effectively improved inflammation and joint destruction in CIA mice. It reduced the production of serum IgG2a and pro-inflammatory cytokines, including serum interleukin (IL)-21, tumor necrosis factor (TNF)-α and IL-6, and the phosphorylation of NF-κB p65 and STAT3 in a dose-dependent manner. More importantly, TGP could suppress the frequency of germinal center B cells and Tfh cells in the spleen.

CONCLUSION

TGP can not only improve symptoms, but also inhibit bone destruction. The therapeutic effect of TGP on CIA is mainly achieved by inhibiting spleen Tfh cell differentiation and GC formation through STAT3 signaling pathway.

Total glucosides of paeony attenuates animal psoriasis induced inflammatory response through inhibiting STAT1 and STAT3 phosphorylation

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is an immune system meditated disease, especially T cells. It disturbed many people around the world and hard to therapy. Paeonia lactiflora Pall has been used as a medicine in china for thousands of years. Recent studies found that the main component of Paeonia lactiflora Pall can alleviates the immune response in many diseases. In this study, we researched the effects and possible mechanisms of total glucosides of paeony (TGP) on animal psoriasis.

AIM OF THE STUDY

To study the therapeutic effects and mechanisms of TGP in 5% propranolol cream-induced psoriasis in guinea pigs and Imiquimod (IMQ) cream-induced psoriasis in mice.

MATERIALS AND METHODS

The effect of TGP was evaluated using a psoriasis-like model of guinea pigs and mice. Ear thickness was accessed, and pathology injury was observed by H&E staining. The levels of serum IL-1β, IL-6, IL-12, IL-17, IL-23, TNF-α, and IFN-γ, skin IL-17A, IL-22 and orphan nuclear receptor (RORγt) mRNA expression, proliferating cell nuclear antigen (PCNA), total or phosphorylated signal transducers and activators of transcription (STAT1, STAT3) were determined by enzyme linked immunosorbent assays (ELISAs), real time PCR, immunohistochemical staining, and western blotting, respectively.

RESULTS

Compared with model group, TGP treatment decreased the ear thickness, improved pathology of psoriasis, alleviated IMQ-induced keratinocyte proliferation, reduced the inflammatory cytokine, and downregulated IL-17A, IL-22, and RORγt mRNA in mice. Further study indicated that TGP inhibited STAT1 and STAT3 phosphorylation in lesion skins of psoriasis-like mice.

CONCLUSIONS

TGP alleviates the symptoms of psoriasis-like guinea pigs and mice, and the possible mechanism may relate to inhibit T helper 17 (TH17) cell differentiation and keratinocytes proliferation by inhibiting STAT1 and STAT3 phosphorylation.

Dynamic Alterations in the Gut Microbiota of Collagen-Induced Arthritis Rats Following the Prolonged Administration of Total Glucosides of Paeony

Rheumatoid arthritis (RA) is a common autoimmune disease linked to chronic inflammation. Dysbiosis of the gut microbiota has been proposed to contribute to the risk of RA, and a large number of researchers have investigated the gut-joint axis hypothesis using the collagen-induced arthritis (CIA) rats. However, previous studies mainly involved short-term experiments; very few used the CIA model to investigate changes in gut microbiota over time. Moreover, previous research failed to use the CIA model to carry out detailed investigations of the effects of drug treatments upon inflammation in the joints, hyperplasia of the synovium, imbalance in the ratios of Th1/Th2 and Th17/Treg cells, intestinal cytokines and the gut microbiota following long-term intervention. In the present study, we carried out a 16-week experiment to investigate changes in the gut microbiota of CIA rats, and evaluated the modulatory effect of total glucosides of paeony (TGP), an immunomodulatory agent widely used in the treatment of RA, after 12 weeks of administration. We found that taxonomic differences developed in the microbial structure between the CIA group and the Control group. Furthermore, the administration of TGP was able to correct 78% of these taxonomic differences, while also increase the relative abundance of certain forms of beneficial symbiotic bacteria. By the end of the experiment, TGP had reduced body weight, thymus index and inflammatory cell infiltration in the ankle joint of CIA rats. Furthermore, the administration of TGP had down-regulated the synovial content of VEGF and the levels of Th1 cells and Th17 cells in CIA rats, and up-regulated the levels of Th2 cells and Treg cells. The administration of TGP also inhibited the levels of intestinal cytokines, secretory immunoglobulin A (SIgA) and Interferon-γ (IFN-γ). In conclusion, the influence of TGP on dynamic changes in gut microbiota, along with the observed improvement of indicators related to CIA symptoms during 12 weeks of administration, supported the hypothesis that the microbiome may play a role in TGP-mediated therapeutic effects in CIA rats. The present study also indicated that the mechanism underlying these effects may be related to the regulation of intestinal mucosal immunity remains unknown and deserves further research attention.

Total Glycosides of Peony Protects Against Inflammatory Bowel Disease by Regulating IL-23/IL-17 Axis and Th17/Treg Balance

Inflammatory bowel disease (IBD) is a group of autoimmune diseases, including ulcerative colitis and Crohn’s disease, characterized by nonspecific inflammation in the gut. Total glycoside of peony (TGP) has been widely used for treatment of autoimmune diseases because of its pharmacological effects. However, it is lack of depth in whether TGP regulate T helper 17 cell (Th17) / T regulatory cell (Treg) immune balance or interleukin 23 (IL-23) / IL-17 axis to achieve the goal of treating IBD. Hence, the aim of this study was to investigate the effects of TGP on experimental colitis mice and the related mechanisms. In the present study, we demonstrated that administration of TGP effectively attenuates colonic inflammation of TNBS-induced colitis mice, mainly reflected in significantly improved clinical parameters, reduced inflammatory response and myeloperoxidase (MPO) activity, even stronger systemic immune ability and effective improvement of Th17/Treg immune disorders. In addition, there was a stronger immunosuppressive ability in a positive cluster of differentiation 4 (CD4[Formula: see text]) T-lymphocytes from the TGP treated mouse colon, characterized by the inhibition of high levels of inflammatory factors and increased regulatory T cells. Importantly, high-dose TGP has similar therapeutic effects as salicylazosulfapyridine (SASP) on IBD treatment. The potential mechanisms might be, at least in part, related to the adjustment of imbalance of Th17/Treg cells and the inhibition of IL-23/IL17 inflammatory signal axis.

The efficacy and safety of total glucosides of peony in the treatment of primary Sjögren's syndrome: a multi-center, randomized, double-blinded, placebo-controlled clinical trial

To evaluate the efficacy and safety of total glucosides of peony (TGP) in adults with primary Sjögren's syndrome (pSS). A multi-center, randomized, double-blinded, placebo-controlled study was conducted between March 2012 and July 2014 at ten Chinese hospitals. In total, 320 pSS patients-classified according to the 2002 American-European Consensus Group Criteria-were randomized (2:1 ratio) to receive TGP(600 mg, tid) in the TGP group or placebo for 24 weeks in the placebo group. Study personnel, investigators, and patients were blinded to the treatment grouping. The primary endpoint was the improvement of EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) at week 24. The secondary endpoints were dry eyes/mouth/skin/nose/throat/vagina visual analogue scale (VAS), pain and discomfort VAS, fatigue VAS, mental discomfort VAS, patient global assessment (PGA), EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI), Schirmer's test, basal/stimulated salivary flow-rate values, and erythrocyte sedimentation rate (ESR). All adverse events were recorded during the trial period. ESSPRI improved more in the TGP than the placebo group (p < 0.001). Dry eyes/throat/vagina VAS, fatigue VAS, mental discomfort VAS, PGA, Schirmer's test, and ESR also improved more in the TGP group than in the placebo group (all p < 0.05). Stimulated salivary flow-rate values increased in the TGP group at week 12 but not at week 24. Adverse events in TGP group were 10.9%. TGP can alleviate some dryness symptoms as well as disease activity in pSS patients over 24 weeks. TGP was well tolerated by study subjects. TGP seems to be an effective and safe treatment for pSS.

Total glucosides of paeony suppresses experimental autoimmune uveitis in association with inhibition of Th1 and Th2 cell function in mice

Total glucosides of paeony (TGP) are active components extracted from the roots of Paeonia lactiflora Pall. In this study, we investigated the role and mechanisms of TGP in experimental autoimmune uveitis (EAU) model of mice. The C57BL/6 mice were randomly divided into three groups: sham group, EAU-control group, and EAU-TGP group. Clinical score of images of the eye fundus were taken on 7, 14, 21, and 28 days after induction of EAU. The concentrations of proinflammatory cytokines in intraocular fluid were measured at 14 days after EAU induction with the use of a multiplex assay system. Flow cytometry was used to analyze the frequency of CD4+, CD8+, interferon-gamma (IFN-γ), and CD4+/CD8+ ratio in spleen and lymph nodes. Western blotting was used to measure expressions of mitogen-activated protein kinase (MAPK) pathway-related proteins in retina. Clinical scores for uveitis were lower in TGP-treated EAU mice than those without TGP treatment. Importantly, the concentrations of cytokines induced by T-helper 1 (Th1) and T-helper 2 (Th2) cells in intraocular fluid were reduced in EAU mice treated with TGP. Furthermore, the frequency of CD4+, IFN-γ, and CD4+/CD8+ ratio was decreased and the frequency of CD8+ was increased in spleen and lymph nodes of mice treated with TGP. The anti-inflammatory effects of TGP were mediated by inhibiting the MAPK signaling pathways. Our results showed that TGP suppressed uveitis in mice via the inhibition of Th1 and Th2 cell function. Thus, TGP may be a promising therapeutic strategy for uveitis, as well as other ocular inflammatory diseases.

Paeoniflorin ameliorates collagen-induced arthritis via suppressing nuclear factor-κB signalling pathway in osteoclast differentiation

Paeoniflorin (PF), extracted from the root of Paeonia lactiflora Pall, exhibits anti-inflammatory properties in several autoimmune diseases. Osteoclast, the only somatic cell with bone resorbing capacity, was the direct cause of bone destruction in rheumatoid arthritis (RA) and its mouse model, collagen-induced arthritis (CIA). The objective of this study was to estimate the effect of PF on CIA mice, and explore the mechanism of PF in bone destruction. We demonstrated that PF treatment significantly ameliorated CIA through inflammatory response inhibition and bone destruction suppression. Furthermore, PF treatment markedly decreased osteoclast number through the altered RANKL/RANK/OPG ratio and inflammatory cytokines profile. Consistently, we found that osteoclast differentiation was significantly inhibited by PF through down-regulation of nuclear factor-κB activation in vitro. Moreover, we found that PF suppressed nuclear factor-κB activation by decreasing its translocation to the nucleus in osteoclast precursor cells. Taken together, our new findings provide insights into a novel function of PF in osteoclastogenesis and demonstrate that PF would be a new therapeutic modality as a natural agent for RA treatment and other autoimmune conditions with bone erosion.

Total glucosides of paeony ameliorates TNBS‑induced colitis by modulating differentiation of Th17/Treg cells and the secretion of cytokines

The imbalance between effector CD4+ T helper 17 (Th17) and regulatory CD4+ T cells (Treg) cells and their associated cytokines, have been associated with the pathogenesis of inflammatory bowel disease (IBD). Total glycosides of paeony (TGP) is an alternative immunomodulatory agent that is widely used for the treatment of autoimmune diseases. The present study aimed to evaluate the modulatory effect of TGP in a rat model of colitis induced by 2,4,6‑trinitrobenzene sulfonic acid (TNBS). TGP was administered intragastrically 24 h after the TNBS intrarectal instillation for 7 days. TGP treatment ameliorated the clinical status and reversed the histopathologic severity of acute TNBS colitis. Furthermore, TGP inhibited the levels of Th17‑associated cytokines interleukin (IL)‑17, IL‑6, tumor necrosis factor‑α, whereas the expression levels of Treg‑associated cytokines IL‑10, transforming growth factor‑β in the plasma, colon, spleen and mesenteric lymph nodes (MLN). Additionally, TGP reduced the percentage of Th17 cells; however, the proportion of Treg cells in the spleen and MLN was increased. The present study also observed a suppression of Th17‑associated transcription factor, termed retinoid‑related orphan receptor‑γt (ROR‑γt). However, expression of the Treg‑associated transcription factor forkhead boxp3 was increased in the TGP treatment group. Therefore, the present findings suggest that TGP has a regulatory role in modulating the balance of Th17 and Treg cells to ameliorate the TNBS‑induced colitis and support the strategy of using TGP to treat IBD.

A systemic review and meta-analysis of the clinical efficacy and safety of total glucosides of peony combined with methotrexate in rheumatoid arthritis

To assess the efficacy and safety of the combination of total glucoside of peony (TGP) and methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). Randomized controlled trial (RCT) data on the traditional Chinese active component TGP combined with MTX vs. MTX alone for the treatment of RA was collected by searching the Pubmed, Embase, Cochrane Library, CNKI, VIP Journals database, and Wanfang database up to February 2017. Study selection, data extraction, data synthesis, and data analyses were performed according to the Cochrane standards. A total of eight RCTs involving 522 participants were included in this meta-analysis. Compared with MTX alone, the use of TGP combined with MTX exhibited better therapeutic effects for the treatment of RA (P = 0.004). In addition, TGP combined with MTX caused a more significant decrease in erythrocyte sedimentation rate (ESR) (P < 0.0001) and swollen joint count (SJC) (P < 0.00001). However, no significant differences were found in C-reactive protein (CRP) (P = 0.19), duration of morning stiffness (DMS) (P = 0.32), or tender joint count (TJC) (P = 0.23) between the two groups. In addition, adverse events were more frequently reported in the MTX monotherapy group than in the TGP and MTX combination group (P = 0.0007). Our study demonstrates that TGP combined with MTX is more effective than MTX alone for the treatment of RA. Nevertheless, the adverse effects of the combination of TGP and MTX need to be further assessed. Due to the poor methodological quality of included trials, well-designed, multi-center, and large-scale RCTs are necessary to draw a more definitive conclusion.

Clinical Efficacy and Safety of Total Glucosides of Paeony for Primary Sjögren's Syndrome: A Systematic Review

OBJECTIVE

To evaluate the clinical efficacy and safety of total glucosides of paeony (TGP) for primary Sjögren's syndrome (pSS).

METHODS

Eight electronic databases were searched from their inception to July 2016. Clinical randomized controlled trials (RCTs) were included. The study quality was evaluated according to the standard suggested in the Cochrane Handbook. RevMan 5.1 was used for statistical analysis.

RESULTS

Seven RCTs involving 443 patients were included. The results showed that TGP combined with an immunosuppressant (IS) showed greater efficacy for improving the saliva flow test of pSS compared to immunosuppressant alone (WMD -6.88, 95% CI -9.02 to -4.74, and P < 0.00001). And the same trend favouring TGP-IS dual combination was found in Schirmer test (WMD 1.63, 95% CI 0.26 to 3.01, and P = 0.02), ESR (WMD 7.33, 95% CI -10.08 to -4.59, and P < 0.00001), CRP (WMD -6.00, 95% CI -7.17 to -4.83, and P < 0.00001), IgM (WMD = -0.42, 95% CI -0.70 to 0.13, and P = 0.004), and IgG (WMD -3.22, 95% CI -4.32 to -2.12, and P < 0.00001) analysis. However, TGP did not affect IgA (WMD 0.53, 95% CI -1.34 to -0.29, and P = 0.20). The adverse events manifested no significant differences between the two groups.

CONCLUSIONS

The TGP-IS combination is superior to IS alone in the treatment of pSS. However, due to the low quality of included studies, high-quality RCTs are needed to confirm the beneficial effects of TGP.

Essential oil-mediated glycerosomes increase transdermal paeoniflorin delivery: optimization, characterization, and evaluation in vitro and in vivo

In this study, a novel glycerosome carrier containing essential oils was prepared for topical administration of paeoniflorin (PF) to enhance its transdermal drug delivery and improve drug absorption in the synovium. The formulation of glycerosomes was optimized by a uniform design, and the final vehicle was composed of 5% (w/v) phospholipid, 0.6% (w/v) cholesterol, and 10% (v/v) glycerol, with 2% (v/v) Speranskia tuberculata essential oil (STO) as the transdermal enhancer. The in vitro transdermal flux of PF loaded in the STO-glycerosomes was 1.4-fold, 1.6-fold, and 1.7-fold higher than those of glycerosomes, liposomes, and tinctures, respectively. In vivo studies showed that the use of STO-glycerosomes was associated with a 3.1-fold greater accumulation of PF in the synovium than that of common glycerosomes. This finding was confirmed by in vivo imaging studies, which found that the fluorescence intensity of Cy5.5-loaded STO-glycerosomes in mice knee joints was 1.8-fold higher than that of the common glycerosomes 5 h after administration. The glycerosomes mediated by STO exhibited considerable skin permeability as well as improved drug absorption in the synovium, indicating that STO-glycerosomes may be a potential PF transdermal delivery vehicle for the treatment of rheumatoid arthritis caused by synovium lesions.

Blockade of IL-7Rα alleviates collagen-induced arthritis via inhibiting Th1 cell differentiation and CD4+ T cell migration

T cell response is crucial to the pathogenesis and progression of rheumatoid arthritis (RA). IL-7/IL-7R axis has significant effect on CD4⁺ T cell response, including proliferation, differentiation, survival and migration. However, whether blockade of IL-7/IL-7R axis signaling can relieve RA and what is the potential treatment mechanisms are still remaining unclear. In this paper, we established collagen-induced arthritis (CIA) model and observed the effect of IL-7Rα antibody in the treatment of CIA mice. It is demonstrated that IL-7Rα antibody significantly alleviated clinical symptoms of CIA mice, accompanied with reduced CD4⁺ T cell number in both spleen and joints. Decreased CII-specific CD4⁺ T cell proliferation and reduced mRNA expression of inflammatory cytokines in IL-7Rα antibody-treated mice were observed. Subsequently, IL-7Rα antibody treatment in vivo downregulated the percentages of Th1 and Th17 cells and the mRNA expression of T-bet and RORγt gene. Moreover, it was found that IL-7 promoted Th1 cell differentiation in vitro, while having no effect on Th17 cell differentiation. In addition, administration of IL-7Rα antibody reduced the mRNA expression of chemokine receptors (CCR7, CXCR3, CXCR6 and XCR1) on CD4⁺ T cells and chemokine CXCL2 in joints. The results suggested that IL-7Rα antibody treated CIA mice via the inhibition of CII-specific CD4⁺ T cell proliferation, the reduction of Th1 cell differentiation and the restrain of CD4⁺ T cell migration to joint lesion site. This investigation indicates that IL-7Rα is a potential therapeutic target for RA.

Clinical and immunological consequences of total glucosides of paeony treatment in Sjögren's syndrome: A randomized controlled pilot trial

BACKGROUND

The total glucosides of paeony (TGP) can inhibit inflammation and alleviate symptoms in autoimmune diseases. This study investigated the clinical and immunological consequences of TGP treatment in patients with primary Sjögren's syndrome (SS).

METHODS

We conducted a randomized, double-blinded, placebo-controlled clinical trial in 45 patients with primary SS. Patients were randomized at 2:1 ratio to either TGP group (n=29) or placebo group (n=16) and followed up for 24weeks. The primary outocme was the European League Against Rheumatism Sjögren's Syndrome Patient Reported Index (ESSPRI). The secondary outcomes were stimulated and unstimulated salivary flow rate, Schirmer's test and erythrocyte sedimentation rate (ESR), immuneglobulin (Ig), anti-nuclear antibody (ANA), anti-SSA, and anti-SSB. The proportions of B cells in peripheral blood and the levels of serum inerleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and B cell activating factor belonging to the TNF family (BAFF) were measured at baseline and at the end of follow up of 24weeks.

RESULTS

The average score of ESSPRI in both groups had no statistical significance at 24th week. The mean of ESSPRI in the dry-mouth part of questionnaire in patients who scored 3 to 6 points was significantly reduced in the TGP group changed from (4.81±0.60) at baseline to (4.20±1.46) (P=0.027) at week 24. Stimulated salivary flow rate increased at week 24 from (1.80±0.39) to (2.01±0.51) (P=0.031) and unstimulated salivary flow rate increased from (0.65±0.46) to (0.78±0.45) (P=0.011) in the TGP group, but the placebo group showed no significant difference. Erythrocyte sedimentation rate (ESR) was decreased significantly compared to the placebo group at 12- and 24-week from (40.9±18.0) to (29.4±12.2) (P=0.003) and (30.4±17.3) (P=0.024). The percentage of naive B cells decreased at week 24 in the TGP group from (77.34±12.20) to (64.59±15.60) (P=0.005) while memory B cells increased from (21.79±11.97) to (34.21±15.48) (P=0.006) respectively. The concentrations of TNF-α and IFN-γ decreased in the TGP group at week 24 from (32.51±26.67) to (24.22±13.56) (P=0.017) and (10.71±8.94) to (6.55±4.88) (P=0.022), respectively. No significant difference in ANA titer, anti-SSA antibodies, anti-SSB antibodies, C3 concentration or C4 concentration was observed between the two groups.

CONCLUSION

TGP appears to improve the glandular secreting function and decrease the level of inflammatory cytokines.

Paeoniflorin suppresses inflammatory response in imiquimod-induced psoriasis-like mice and peripheral blood mononuclear cells (PBMCs) from psoriasis patients

Psoriasis is one of the most common immune-mediated chronic inflammatory skin disorders, characterized by hyperproliferation of keratinocytes, dilation and growth of dermal capillary vasculature, and cellular infiltration of T cells, dendritic cells (DCs), and neutrophils. Paeoniflorin (PF), the principal component of total glucosides of paeony (TGP), displays anti-inflammatory and antioxidant properties in several animal models. In this study, we investigated the anti-inflammatory effects and mechanisms of PF in imiquimod (IMQ)-induced psoriasis-like mouse model. The effects of PF on inflammatory cytokine expression in peripheral blood mononuclear cells (PBMCs) from patients with psoriasis vulgaris were also observed. Our results indicated that PF effectively attenuated the clinical and histopathologic changes in IMQ-induced psoriasis-like mouse model. Furthermore, PF reduced the infiltration of T cells, CD11c+DCs, and neutrophils in lesional skin. In addition, PF also significantly decreased the mRNA expression of inflammatory cytokines, such as IL-17, INF-γ, IL-6, and TNF-α, in IMQ-induced psoriasis-like mouse model and PBMCs from patients with psoriasis vulgaris. Hence, our data suggest that PF can inhibit leukocyte infiltration and decrease the expression of inflammatory cytokines such as IL-17, INF-γ, IL-6, and TNF-α. PF might be a candidate drug for the treatment of psoriasis.

Modulation of dendritic cell immune functions by plant components

Dendritic cells (DCs) are the key linkage between innate and adoptive immune response. DCs are classified as specialized antigen-presenting cells that initiate T-cell immune responses during infection and hypersensitivity, and maintain immune tolerance to self-antigens. Initiating T-cell immune responses may be beneficial in infectious diseases or cancer management, while, immunosuppressant or tolerogenic responses could be useful in controlling autoimmunity, allergy or inflammatory diseases. Several types of plant-derived components show promising properties in influencing DC functions. Various types of these components have been proven useful in clinical application and immune-based therapy. Therefore, focusing on the benefits of plant-based medicine regulating DC functions may be useful, low-cost, and accessible strategies for human health. This review illustrates recent studies, investigating the role of plant components in manipulating DC phenotype and function towards immunostimulating or immunosuppressing effects either in vitro or in vivo.

Unique immunomodulatory effect of paeoniflorin on type I and II macrophages activities

It has been widely accepted that macrophages are divided into M1 "pro-inflammatory" macrophages and M2 "anti-inflammatory" macrophages and an uncontrolled macrophage polarization plays an important role in the pathogenesis of different diseases. As the main substance of total glucosides of peony, paeoniflorin (PF), has been widely used to treat autoimmune and autoinflammatory diseases for years. Mechanistically, PF has been found to alter activities of many immune cells, which could further reduce inflammation and tissue damage. However, whether and how PF affects macrophages activities in vitro remains unknown. In current study, using M1 and M2 cells generated from mouse bone marrow precursors, we explored the role of PF in regulating M1/M2 cells activity in vitro. The results showed that PF inhibited LPS-induced M1 activity by reducing iNOS expression and NO production via decreasing LPS/NF-κB signaling pathway; whereas, PF enhanced IL-4-provoked M2 function by up-regulating Arg-1 production and activity via increasing IL-4/STAT6 signaling pathway. Our new finding indicates that PF can suppress M1 cells activity and enhance M2 cells function simultaneously, which could help to ameliorate autoimmune and autoinflammatory diseases in clinical treatment.

Paeoniflorin regulates the function of human peripheral blood mononuclear cells stimulated by rhIL-1β by up-regulating Treg expression

The aim of the present study was to investigate the effect of paeoniflorin (Pae) on recombinant human interleukin-1β (rhIL-1β)-stimulated human peripheral blood mononuclear cells (PBMCs) in vitro. PBMCs were collected by Ficoll density gradient centrifugation and were co-cultured with rhIL-1β for different time periods. The proliferation response was determined by a cell counting kit-8 (CCK-8) assay. The production of IL-17 and IL-10 was measured by enzyme-linked immunosorbent assay (ELISA). The percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) was detected by flow cytometry analysis. These results indicated that rhIL-1β stimulation induced the proliferation of PBMCs in a concentration- and time-dependent manner; it also increased the level of IL-17 and decreased the level of IL-10 in a concentration-dependent manner. The flow cytometry analysis demonstrated that the stimulation of rhIL-1β significantly downregulated the percentage of CD4(+)CD25(+)Foxp3(+) Treg in CD4(+) T cells. However, administration of Pae significantly suppressed the proliferation response of rhIL-1β-induced PBMCs and regulated the secretion function of IL-17 and IL-10. Additional experiments demonstrated that Pae treatment significantly reduced rhIL-1β-induced decreases in PBMCs CD4(+)CD25(+)Foxp3(+) subpopulation numbers. These results suggest that the anti-inflammatory action of Pae is attributable to its regulation of IL-17/IL-10 secretion and Treg expression.

Total glucosides of peony attenuates experimental autoimmune encephalomyelitis in C57BL/6 mice

Total glucosides of peony (TGP), an active compound extracted from the roots of Paeonia lactiflora Pall, has wide pharmacological effects on nervous system. Here we examined the effects of TGP on experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). The results showed that TGP can reduce the severity and progression of EAE in C57 BL/6 mice. In addition, TGP also down-regulated the Th1/Th17 inflammatory response and prevented the reduced expression of brain-derived neurotrophic factor and 2',3'-cyclic nucleotide 3'-phosphodiesterase of EAE. These findings suggest that TGP could be a potential therapeutic agent for MS.

Paeoniflorin diminishes ConA-induced IL-8 production in primary human hepatic sinusoidal endothelial cells in the involvement of ERK1/2 and Akt phosphorylation

Liver diseases are closely associated with elevated levels of interleukin-8 (IL-8), suggesting the ability to inhibit IL-8 production could enhance the treatment of liver diseases. Paeoniflorin is a major active constituent of dried Paeoniae Radix Alba root (Baishao in Chinese) which is widely used in China to treat liver diseases. We examined the effects and underlying mechanisms of paeoniflorin on IL-8 production in primary human hepatic sinusoidal endothelial cells (HHSECs). Concanavalin A (ConA) at 20 μg/mL produced a 5.2-fold increase in IL-8 mRNA by 8h, and a 14.2-fold rise in IL-8 levels by 16 h. Inhibition of MEK (ERK kinase) and extracellular signal-regulated kinase (ERK) by PD98059 and U0126, or inhibition of phosphatidylinositol 3-kinase (PI3K) by LY294002 blocked both ConA-induced IL-8 mRNA expression and IL-8 secretion. Paeoniflorin reduced ConA-induced IL-8 mRNA expression and IL-8 release by 57.9% and 52.8%, respectively, and also decreased ConA-stimulated phosphorylation of ERK1/2 and Akt, suggesting paeoniflorin inhibits IL-8 expression and release by inhibiting the ERK1/2 and Akt pathways. Combining paeoniflorin with U0126 or LY294002 at low doses showed supra-additive inhibition of not only phospho-ERK1/2 and phospho-Akt by 46.4% and 35.0%, but also IL-8 release by 42.4% and 36.1% and IL-8 mRNA expression by 43.5% and 31.8%, respectively. In conclusion, paeoniflorin most likely contributes to the therapy for liver disease by exerting anti-inflammatory effects on HHSECs through blocking IL-8 secretion via downregulation of ERK1/2 and Akt phosphorylation.

Paeoniflorin inhibits skin lesions in imiquimod-induced psoriasis-like mice by downregulating inflammation

Psoriasis is a common chronic immune-mediated inflammatory disease. It is well known that macrophages, neutrophils and T-helper 1 (Th1)/T-helper 17 (Th17) cells play important roles in skin lesions by provoking inflammation. Paeoniflorin (PF) is the major effective component extracted from the root of Paeonia lactiflora, which has been widely used in China to treat inflammatory and autoimmune diseases, including psoriasis. Although PF shows a clinical therapeutic effect on psoriasis patients, how PF affects infiltrated immune cells in psoriasis skin lesions is still unknown. In this study, using a generated imiquimod (IMQ)-induced psoriasis-like mouse model, we found that PF ameliorates inflammation and skin lesions. Subsequent analyses showed that PF decreases the number of F4/80(+)CD68(+) macrophages and their related cytokine production (TNF-α, IL-1β, IL-6, IL-12 and inducible nitric oxide synthase (iNOS)) in the skin of IMQ-challenged mice. Moreover, PF suppresses the number of CD11b(+)Gr-1(+) neutrophils and the expression of macrophage inflammatory protein-2 (MIP-2; a counterpart of human IL-8, which is responsible for the recruitment of neutrophils in mice). Finally, PF also down-regulates Th1- and Th17-related cytokine expression. Therefore, our new findings reveal that PF alleviates psoriatic skin lesions by inhibiting inflammation, which provides new insights into the immunomodulatory effect of PF in psoriasis treatment.

Immunosuppressive effect of Chinese medicine on T helper 17 cells

T helper (Th)17 cells have been proposed to play important roles in several human diseases. The literatures about Chinese medicine studies, which related to inhibiting Th17, were reviewed, and the Chinese medicine which could inhibit Th17 cells was summarized in this paper.