Oxymatrine hydrazone (OMTH) synthesis and its protective effect for rheumatoid arthritis through downregulation of MEK/NF-κB pathway

Therapeutic potential of phytocompounds in rheumatoid arthritis: Molecular insights and clinical applications

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic involvement, inflammation, and the destruction of synovial joints. RA can be categorized as anti-citrullinated protein antibodies-positive or negative based on genetic risk factors and autoantibodies. This review systematically sourced articles related to RA, phytocompounds, signaling pathways, and clinical insights from primary medical databases, including Scopus, PubMed, and Web of Science. This review explores the therapeutic potential of phytocompounds in treating RA by targeting key inflammation and immunological response signaling pathways. Phytocompounds such as curcumin, resveratrol, and flavonoids alter essential molecular pathways in RA pathophysiology, including nuclear factor kappa-light-chain-enhancer of activated B cells, mitogen-activated protein kinases, janus kinase-signal transducer and activator of transcription, and the inflammasome. These substances possess pro-resolving, anti-apoptotic, and antioxidant properties, which enhance their therapeutic efficacy. Alternative medicine, including dietary, herbal, and nutritional supplements, may help reduce RA symptoms. In vitro, in vivo, and clinical studies have demonstrated the effectiveness of these treatments. Phytocompounds have potential as a treatment for RA by altering signaling pathways, reducing oxidative stress, and protecting cartilage and bone. However, few clinical trials confirm its long-term safety, bioavailability, and effectiveness. Further clinical trials and translational research are needed to validate the effectiveness, safety, and pharmacokinetics of phytocompounds, while identifying novel plant-derived bioactive chemicals could improve patient outcomes.

RIP1 inhibition reduces chondrocyte apoptosis through downregulating nuclear factor-kappa B signaling in a mouse osteoarthritis model

BACKGROUND

Excessive chondrocyte death is a critical player in the process of osteoarthritis (OA). The present study was aimed to study the role of receptor-interacting serine/threonine kinase (RIP) 1-mediated signaling for programmed cell death in OA.

METHODS

In the present study, RIP1 protein expression was evaluated in mouse OA cartilage and cultured primary murine chondrocytes exposed to tumor necrosis factor-alpha (TNF-α). Protein expression involved in necroptosis and apoptosis and chondrocyte-derived extracellular matrix were examined. Inhibition of RIP1 was conducted using the RNAi technique and pharmacological inhibition. Western blot, immunohistochemistry, and immunofluorescence examination were applied.

RESULTS

The protein presence of RIP1, but not RIP3, was increased in the mouse OA tissue and cultured chondrocytes exposed to TNF-α. Knockdown of RIP1 increased protein expression of collagen II and sex-determining region Y-box transcription factor 9, and reduced protein expression of matrix metallopeptidases 13 and a disintegrin and metalloproteinase with thrombospondin motifs 5. Inhibition of RIP1 reduced the phosphorylated NF-κB signals, decreased cell apoptosis, and restored extracellular matrix expression in cultured chondrocytes. Both RNAi and pharmacological inhibition of RIP1 decelerated the progress of OA in mice.

CONCLUSION

RIP1 regulates chondrocyte apoptosis through NF-κB signaling. Inhibition of RIP1 provides a novel therapeutic approach for OA therapy.

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.

Advances of the small molecule drugs regulating fibroblast-like synovial proliferation for rheumatoid arthritis

Rheumatoid arthritis (RA) is a type of chronic autoimmune and inflammatory disease. In the pathological process of RA, the alteration of fibroblast-like synoviocyte (FLS) and its related factors is the main influence in the clinic and fundamental research. In RA, FLS exhibits a uniquely aggressive phenotype, leading to synovial hyperplasia, destruction of the cartilage and bone, and a pro-inflammatory environment in the synovial tissue for perpetuation and progression. Evidently, it is a highly promising way to target the pathological function of FLS for new anti-RA drugs. Based on this, we summed up the pathological mechanism of RA-FLS and reviewed the recent progress of small molecule drugs, including the synthetic small molecule compounds and natural products targeting RA-FLS. In the end, there were some views for further action. Compared with MAPK and NF-κB signaling pathways, the JAK/STAT signaling pathway has great potential for research as targets. A small number of synthetic small molecule compounds have entered the clinic to treat RA and are often used in combination with other drugs. Meanwhile, most natural products are currently in the experimental stage, not the clinical trial stage, such as triptolide. There is an urgent need to unremittingly develop new agents for RA.

MicroRNA-345-3p is a potential biomarker and ameliorates rheumatoid arthritis by reducing the release of proinflammatory cytokines

OBJECTIVES

The study was to explore the influence of microRNA (miR)-345-3p on proinflammatory cytokines in patients with rheumatoid arthritis (RA).

METHODS

A total of 32 RA patients and 32 healthy patients were enrolled. Proinflammatory factors in patients' serum were detected by ELISA, and miR-345-3p was detected by RT-qPCR. The correlation between miR-345-3p expression and proinflammatory factors in RA patients was analyzed. The diagnostic value of miR-345-3p and proinflammatory factors in RA patients was analyzed by receiver operating curve diagnosis. The predictive value of miR-345-3p levels and proinflammatory factors in RA patients was analyzed by multivariate Cox regression. HFLS-RA and HFLS cells were cultured, in which miR-345-3p and proinflammatory cytokines were detected by RT-qPCR. Cell proliferation and apoptosis were determined by CCK-8 and flow cytometry, respectively.

RESULTS

MiR-345-3p was lowly expressed in the serum of RA patients. MiR-345-3p and proinflammatory factors were of diagnostic and predictive values in RA. Elevated miR-345-3p restrained the production of proinflammatory factors of HFLS-RA cells, improved cell proliferation, and reduced apoptosis.

CONCLUSION

MiR-345-3p is a potential biomarker and ameliorates RA by reducing the release of proinflammatory cytokines.

Oxymatrine ameliorates osteoarthritis via the Nrf2/NF-κB axis in vitro and in vivo

PURPOSE

Osteoarthritis (OA) is a common degenerative joint disorder. Currently, the underlying etiology of OA is still far from fully elucidated and there is no cure for OA progression. Previous studies have demonstrated that oxymatrine (OMT) could inhibit inflammation and oxidative stress in several animal models. However, the potential effects of OMT on OA remain largely elusive. The aim of the study is to investigate the anti-inflammatory and chondrocyte protective effect of OMT, and delineate the potential mechanism in vitro and in vivo.

METHODS

Western blotting, RT-qPCR, ELISA and tissue staining were employed to explore the mechanisms by which OMT exerted a protective effect on IL-1β-induced production of pro-inflammation cytokines and extracellular matrix (ECM) degradation in primary murine chondrocytes and DMM mouse models.

RESULTS

The results showed that OMT reduced the IL-1β-induced over-production of pro-inflammation cytokines and ECM degradation. Mechanistically, OMT inhibited the NF-κB pathway via activating Nrf2. In vivo studies also demonstrated that OMT ameliorated OA progression.

CONCLUSIONS

OMT reduced pro-inflammation cytokines, ECM degradation and OA progression via activating Nrf2 and inhibiting NF-κB pathway.

Oxymatrine boosts hematopoietic regeneration by modulating MAPK/ERK phosphorylation after irradiation-induced hematopoietic injury

Hematopoietic toxicity due to ionizing radiation (IR) is a leading cause of death in nuclear incidents, occupational hazards, and cancer therapy. Oxymatrine (OM), an extract originating from the root of Sophora flavescens (Kushen), possesses extensive pharmacological properties. In this study, we demonstrate that OM treatment accelerates hematological recovery and increases the survival rate of mice subjected to irradiation. This outcome is accompanied by an increase in functional hematopoietic stem cells (HSCs), resulting in an enhanced hematopoietic reconstitution ability. Mechanistically, we observed significant activation of the MAPK signaling pathway, accelerated cellular proliferation, and decreased cell apoptosis. Notably, we identified marked increases in the cell cycle transcriptional regulator Cyclin D1 (Ccnd1) and the anti-apoptotic protein BCL2 in HSC after OM treatment. Further investigation revealed that the expression of Ccnd1 transcript and BCL2 levels were reversed upon specific inhibition of ERK1/2 phosphorylation, effectively negating the rescuing effect of OM. Moreover, we determined that targeted inhibition of ERK1/2 activation significantly counteracted the regenerative effect of OM on human HSCs. Taken together, our results suggest a crucial role for OM in hematopoietic reconstitution following IR via MAPK signaling pathway-mediated mechanisms, providing theoretical support for innovative therapeutic applications of OM in addressing IR-induced injuries in humans.

Ebosin Attenuates the Inflammatory Responses Induced by TNF-α through Inhibiting NF-κB and MAPK Pathways in Rat Fibroblast-Like Synoviocytes

Tumor necrosis factor-α (TNF-α) lies at the apex of signal transduction cascades that results in induced destruction of joints in rheumatoid arthritis. It is therefore of great medicinal interest to modulate the cellular responses to TNF-α. Ebosin, a novel exopolysaccharide derived from Streptomyces sp, has been demonstrated to have remarkable therapeutic actions on collagen-induced arthritis in rats, while it also suppressed the production of IL-1β, TNF-α, and IL-6 at both mRNA and protein levels in cultured fibroblast-like synoviocytes. In order to further understand the potential mechanisms involved in the anti-inflammatory effects of ebosin at molecular level, we investigated the impact of it on the activation of MAPK and NF-κB pathways following TNF-α induced in fibroblast-like synoviocytes (FLS). The results showed that the phosphorylation levels of TNF-α-induced p38, JNK1, JNK2, IKKα, IKKβ, and IκB, as well as NF-κB nuclear translocation, were reduced significantly in FLS cells in response to ebosin. Furthermore, we proved that ebosin decreased the level of NF-κB in the nucleus and blocked the DNA-binding ability of NF-κB using electrophoresis mobility gel shift assay. Besides, low levels of matrix metalloproteinases (MMP-1 and MMP-3) and chemokines (interleukin-8 and RANTES) were found in TNF-α-stimulated fibroblast-like synoviocytes treated with ebosin. These results indicate that ebosin can suppress a range of activities in both MAPK and NF-κB pathways induced by TNF-α in rat fibroblast-like synoviocytes, which provides a rationale for examining the use of ebosin as a potential therapeutic candidate for rheumatic arthritis.