Emodin alleviates arthritis pain through reducing spinal inflammation and oxidative stress

Triterpenoids from the leaves of Eleutherococcus sessiliflorus, and their antiproliferative activities in TNF-α induced HFLS-RA cells

Five undescribed elesesterpenes L-U, along with nine known 3,4-seco-lupane-type triterpenoids were isolated from the leaves of Eleutherococcus sessiliflorus (Rupr. & Maxim.) S. Y. Hu. Elesesterpene L-S, and U were lupane-type triterpenoids, whereas elesesterpene T was an oleanane-type triterpenoid, probably artifact, as suggested by LC-MS analysis. Out of the nine known compounds, five were initially identified in E. sessiliflorus. Moreover, their structures were definitively determined using spectroscopic analyses, and the absolute configurations of elesesterpenes L-M and sachunogenin 3-O-glucoside were clarified using X-ray crystallographic techniques. The absolute configuration of elesesterpene T was determined by measuring and calculating its ECD. In addition, all compounds were tested to examine their ability to inhibit the proliferation of HFLS-RA cells induced by TNF-α in vitro. Elesesterpene M, chiisanogenin, chiisanoside, and 3-methylisochiisanoside significantly inhibited HFLS-RA proliferation.

NLRP3 inflammasome and its role in autoimmune diseases: A promising therapeutic target

The NOD-like receptor protein 3 (NLRP3) inflammasome is a protein complex that regulates innate immune responses by activating caspase-1 and the inflammatory cytokines IL-1β and IL-18. Numerous studies have highlighted its crucial role in the pathogenesis and development of inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid diseases, and other autoimmune diseases. Therefore, investigating the underlying mechanisms of NLRP3 in disease and targeted drug therapies holds clinical significance. This review summarizes the structure, assembly, and activation mechanisms of the NLRP3 inflammasome, focusing on its role and involvement in various autoimmune diseases. This review also identifies studies where the involvement of the NLRP3 inflammasome in the disease mechanism within the same disease appears contradictory, as well as differences in NLRP3-related gene polymorphisms among different ethnic groups. Additionally, the latest therapeutic advances in targeting the NLRP3 inflammasome for autoimmune diseases are outlined, and novel clinical perspectives are discussed. Conclusively, this review provides a consolidated source of information on the NLRP3 inflammasome and may guide future research efforts that have the potential to positively impact patient outcomes.

Manual acupuncture ameliorates inflammatory pain by upregulating adenosine A3 receptor in complete Freund's adjuvant-induced arthritis rats

BACKGROUND

Adenosine A3 receptor (A3R) exerts analgesic, anti-inflammatory, and anti-nociceptive effects. In this study, we determined the analgesic mechanism of manual acupuncture (MA) in rats with complete Freund's adjuvant (CFA)-induced arthritis and explored whether MA ameliorates inflammation in these rats by upregulating A3R.

METHODS

Sixty Sprague Dawley (SD) rats were randomly divided into the following groups: Control, CFA, CFA + MA, CFA + sham MA, CFA + MA + DMSO, CFA + MA + IB-MECA, and CFA + MA + Reversine groups. The arthritis rat model was induced by injecting CFA into the left ankle joints. Thereafter, the rats were subjected to MA (ST36 acupoint) for 3 days. The clinical indicators paw withdrawal latency (PWL), paw withdrawal threshold (PWT), and open field test (OFT) were used to determine the analgesic effect of MA. In addition, to explore the effect of A3R on inflammation after subjecting arthritis rats to MA, IB-MECA (A3R agonist) and Reversine (A3R antagonist) were injected into ST36 before MA.

RESULTS

MA ameliorated the pathological symptoms of CFA-induced arthritis, including the pain indicators PWL and PWT, number of rearing, total ambulatory distance, and activity trajectory. Furthermore, after MA, the mRNA and protein expression of A3R was upregulated in CFA-induced arthritis rats. In contrast, the protein levels of TNF-α, IL-1β, Rap1, and p-p65 were downregulated after MA. Interestingly, the A3R agonist and antagonist further downregulated and upregulated inflammatory cytokine expression, respectively, after MA. Furthermore, the A3R antagonist increased the degree of ankle swelling after MA.

CONCLUSION

MA can alleviate inflammatory pain by inhibiting the NF-κB signaling pathway via upregulating A3R expression of the superficial fascia of the ST36 acupoint site in CFA-induced arthritis rats.

Emerging Molecular and Synaptic Targets for the Management of Chronic Pain Caused by Systemic Lupus Erythematosus

Patients with systemic lupus erythematosus (SLE) frequently experience chronic pain due to the limited effectiveness and safety profiles of current analgesics. Understanding the molecular and synaptic mechanisms underlying abnormal neuronal activation along the pain signaling pathway is essential for developing new analgesics to address SLE-induced chronic pain. Recent studies, including those conducted by our team and others using the SLE animal model (MRL/lpr lupus-prone mice), have unveiled heightened excitability in nociceptive primary sensory neurons within the dorsal root ganglia and increased glutamatergic synaptic activity in spinal dorsal horn neurons, contributing to the development of chronic pain in mice with SLE. Nociceptive primary sensory neurons in lupus animals exhibit elevated resting membrane potentials, and reduced thresholds and rheobases of action potentials. These changes coincide with the elevated production of TNFα and IL-1β, as well as increased ERK activity in the dorsal root ganglion, coupled with decreased AMPK activity in the same region. Dysregulated AMPK activity is linked to heightened excitability in nociceptive sensory neurons in lupus animals. Additionally, the increased glutamatergic synaptic activity in the spinal dorsal horn in lupus mice with chronic pain is characterized by enhanced presynaptic glutamate release and postsynaptic AMPA receptor activation, alongside the reduced activity of glial glutamate transporters. These alterations are caused by the elevated activities of IL-1β, IL-18, CSF-1, and thrombin, and reduced AMPK activities in the dorsal horn. Furthermore, the pharmacological activation of spinal GPR109A receptors in microglia in lupus mice suppresses chronic pain by inhibiting p38 MAPK activity and the production of both IL-1β and IL-18, as well as reducing glutamatergic synaptic activity in the spinal dorsal horn. These findings collectively unveil crucial signaling molecular and synaptic targets for modulating abnormal neuronal activation in both the periphery and spinal dorsal horn, offering insights into the development of analgesics for managing SLE-induced chronic pain.

Xuanbai Chengqi Decoction alleviates acute lung injury by inhibiting NLRP3 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a prevalent critical respiratory disorder caused mostly by infection and other factors. However, effective drug therapies are currently lacking. Xuanbai Chengqi Decoction (XCD), a traditional Chinese medicine (TCM) prescription, is commonly employed to treat lung diseases. It has been recommended by Chinese health authorities as one of the TCM prescriptions for COVID-19. Nonetheless, its underlying mechanism for the treatment of ALI has not been fully understood.

AIM OF THE STUDY

The study aims to investigate the therapeutic effect of XCD on lipopolysaccharide (LPS) -induced ALI in mice and explore its anti-inflammatory mechanism involving pyroptosis.

MATERIALS AND METHODS

Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was employed to identify the active compounds of XCD, and quantitative analysis of the main compounds was conducted. Male C57BL/6J mice were given different doses of XCD (4.5 and 9.0 g/kg/day) or dexamethasone (5 mg/kg/day) by oral gavage for 5 consecutive days. Subsequently, ALI was induced by injecting LPS (20 mg/kg) intraperitoneally 2 h after the last administration, and serum and lung tissues were collected 8 h later. J774A.1 cells were pretreated with different doses of XCD (100, 200, 400 μg/ml) for 12 h, then incubated with LPS (1 μg/ml) for 4 h and ATP (1 mM) for 2 h to induce pyroptosis. Supernatant and cells were collected. Moreover, J774A.1 cells were transfected with an NLRP3 overexpression plasmid for 24 h, followed by subsequent experiments with XCD (400 μg/ml). Lung histopathological changes were evaluated using hematoxylin and eosin (HE) staining. To assess the efficacy of XCD on ALI/ARDS, the levels of inflammatory factors, chemokines, and proteins associated with NLRP3 inflammasome signaling pathway were evaluated.

RESULTS

XCD was found to ameliorate lung inflammation injury in ALI mice, and reduce the protein expression of TNF-α, IL-1β, and IL-6 in both mouse serum and J774A.1 cell supernatant. Meanwhile, XCD significantly decreased the mRNA levels of IL-1β, pro-IL-1β, CXCL1, CXCL10, TNF-α, NLRP3, NF-κB P65, and the protein expression of NLRP3, Cleaved-Caspase1, and GSDMD-N in the lung and J774A.1 cells. These effects were consistent with the NLRP3 inhibitor MCC950. Furthermore, overexpression of NLRP3 reversed the anti-inflammatory effect of XCD.

CONCLUSION

The therapeutic mechanism of XCD in ALI treatment may involve alleviating inflammatory responses in lung tissues by inhibiting the activation of the NLRP3 inflammasome-mediated pyroptosis in macrophages.

Integrated Network Pharmacology and Experimental Approach to Investigate the Protective Effect of Jin Gu Lian Capsule on Rheumatoid Arthritis by Inhibiting Inflammation via IL-17/NF-κB Pathway

Purpose

This study aimed to investigate the main pharmacological action and underlying mechanisms of Jin Gu Lian Capsule (JGL) against rheumatoid arthritis (RA) based on network pharmacology and experimental verification.

Methods

Network pharmacology approaches were performed to explore the core active compounds of JGL, key therapeutic targets, and signaling pathways. Molecular docking was used to predict the binding affinity of compounds with targets. In vivo experiments were undertaken to validate the findings from network analysis.

Results

A total of 52 targets were identified as candidate JGL targets for RA. Sixteen ingredients were identified as the core active compounds, including, quercetin, myricetin, salidroside, etc. Interleukin-1 beta (IL1B), transcription factor AP-1 (JUN), growth-regulated alpha protein (CXCL1), C-X-C motif chemokine (CXCL)3, CXCL2, signal transducer and activator of transcription 1 (STAT1), prostaglandin G/H synthase 2 (PTGS2), matrix metalloproteinase (MMP)1, inhibitor of nuclear factor kappa-B kinase subunit beta (IKBKB) and transcription factor p65 (RELA) were obtained as the key therapeutic targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the efficacy of JGL was functionally involved in regulating immune-mediated inflammation, in which IL-17/NF-κB signaling was recommended as one of the main pathways. Molecular docking suggested that the core active compounds bound strongly to their respective targets. Experimentally, JGL treatment mitigated inflammation, showed analgesic activity, and ameliorated collagen-induced arthritis. Enzyme-linked immunosorbent assay showed that JGL effectively reduced the serum levels of cytokines, chemokines, and MMPs. Immunohistochemistry staining showed that JGL markedly reduced the expression of the targets in IL-17/NF-κB pathway including IL-17A, IL-17RA, NF-κB p65, C-X-C motif ligand 2, MMP1 and MMP13.

Conclusion

This investigation provided evidence that JGL may alleviate RA symptoms by partially inhibiting the immune-mediated inflammation via IL-17/NF-κB pathway.

Advances in the pharmacological effects and molecular mechanisms of emodin in the treatment of metabolic diseases

Rhubarb palmatum L., Polygonum multijiorum Thunb., and Polygonum cuspidatum Sieb. Et Zucc. are traditional Chinese medicines that have been used for thousands of years. They are formulated into various preparations and are widely used. Emodin is a traditional Chinese medicine monomer and the main active ingredient in Rhubarb palmatum L., Polygonum multijiorum Thunb., and Polygonum cuspidatum Sieb. Et Zucc. Modern research shows that it has a variety of pharmacological effects, including promoting lipid and glucose metabolism, osteogenesis, and anti-inflammatory and anti-autophagy effects. Research on the toxicity and pharmacokinetics of emodin can promote its clinical application. This review aims to provide a basis for further development and clinical research of emodin in the treatment of metabolic diseases. We performed a comprehensive summary of the pharmacology and molecular mechanisms of emodin in treating metabolic diseases by searching databases such as Web of Science, PubMed, ScienceDirect, and CNKI up to 2023. In addition, this review also analyzes the toxicity and pharmacokinetics of emodin. The results show that emodin mainly regulates AMPK, PPAR, and inflammation-related signaling pathways, and has a good therapeutic effect on obesity, hyperlipidemia, non-alcoholic fatty liver disease, diabetes and its complications, and osteoporosis. In addition, controlling toxic factors and improving bioavailability are of great significance for its clinical application.