Norisoboldine alleviates joint destruction in rats with adjuvant-induced arthritis by reducing RANKL, IL-6, PGE2, and MMP-13 expression

Abstract

Aim: To explore the effects of norisoboldine (NOR), a major isoquinoline alkaloid in Radix Linderae, on joint destruction in rats with adjuvant-induced arthritis (AIA) and its underlying mechanisms. Methods: AIA was induced in adult male SD rats by intradermal injection of Mycobacterium butyricum in Freund's complete adjuvant at the base of the right hind paw and tail. From d 14 after immunization, the rats were orally given NOR (7.5, 15, or 30 mg/kg) or dexamethasone (0.5 mg/kg) daily for 10 consecutive days. Joint destruction was evaluated with radiological scanning and H&E staining. Fibroblast-like synoviocytes (FLS) were prepared from fresh synovial tissues in the AIA rats. The expression of related proteins and mRNAs were detected by ELISA, Western blotting and RT-PCR. Results: In AIA rats, NOR (15 and 30 mg/kg) significantly decreased the swelling of paws and arthritis index scores, and elevated the mean body weight. NOR (30 mg/kg) prevented both the infiltration of inflammatory cells and destruction of bone and cartilage in joints. However, NOR (15 mg/kg) only suppressed the destruction of bone and cartilage, but did not obviously ameliorate synovial inflammation. NOR (15 and 30 mg/kg) significantly decreased the serum levels of receptor activator of nuclear factor κB ligand (RANKL), IL-6, PGE 2 , and MMP-13, but not the osteoprotegerin and MMP-1 levels. The mRNA levels of RANKL, IL-6, COX-2, and MMP-13 in synovium were also suppressed. Dexamethasone produced similar effects in AIA rats as NOR did, but without elevating the mean body weight. In the cultured FLS, treatment with NOR (10 and 30 mmol/L) significantly decreased the secretion of RANKL, IL-6, PGE 2 , and MMP-13 proteins. Furthermore, the treatment selectively prevented the activation of MAPKs, AKT and transcription factor AP-1 component c-Jun, but not the recruitment of TRAF6 or the activation of JAK2/STAT3. Treatment of the cultured FLS with the specific inhibitors of p38, ERK, AKT, and AP-1 significantly decreased the secretion of RANKL, IL-6, PGE 2 , and MMP-13 proteins. Conclusion: NOR can alleviate joint destruction in AIA rats by reducing RANKL, IL-6, PGE 2 , and MMP-13 expression via the p38/ERK/ AKT/AP-1 pathway.

Norisoboldine Suppresses VEGF-Induced Endothelial Cell Migration via the cAMP-PKA-NF-κB/Notch1 Pathway

“…In our previous studies, the anti-migration activity of NOR was partially attributed to the prevention of the Notch1 pathway-related tip cell phenotype [11], [12]. In this study, preliminary experiments were conducted to examine the interplay between the PKA and Notch1 pathways.…”

“…Previous studies have demonstrated that NOR can inhibit VEGF-induced endothelial cell migration [11], [12]. To clarify whether this effect is related to the inhibition of the PKA pathway, the intracytoplasmic cAMP level and PKA activation in HUVECs were investigated.…”

Preparation and drug release properties of norisoboldine-loaded chitosan microspheres

“…The results of preliminary studies in our laboratory indicated that norisoboldine is a potential therapeutic agent for RA that functions by protecting joint destruction and inhibits synovial angiogenesis in the collagen II-induced arthritis of mice [13][14][15][16][17]. However, after a single intravenous administration of NOR to rats, the plasma concentrations of NOR sharply declined, followed by a slower phase of decrease until the levels fell below detection limits in 120 min [18].…”

Establishment of a novel cell-based assay for screening small molecule antagonists of human interleukin-6 receptor

“…However, under some pathological conditions, continuous addition of IL-6 has been shown to increase autoantibodies, such as anti-double-stranded DNA (anti-dsDNA) antibody production, making significant contributions to the inflammatory response and accelerating the progression of autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) [3][4][5] . A blockade of IL-6 or its receptor has been demonstrated to prevent elevated anti-dsDNA antibody levels and the progression of autoimmune diseases in addition to improving survival rates [6] .…”