Traditional Chinese medication for rheumatoid arthritis: more than what meets the eye

Isopsoralen ameliorates rheumatoid arthritis by targeting MIF

BACKGROUND

Isopsoralen (IPRN), one of the active ingredients of Psoralea corylifolia Linn, has anti-inflammatory properties. We attempted to investigate the inhibitory effects of IPRN on rheumatoid arthritis (RA) and characterize its potential mechanism.

METHODS

RA fibroblast-like synoviocytes (FLSs) and mice with collagen-induced arthritis (CIA) were used as in vitro and in vivo models to analyze the antiarthritic effect of IPRN. Histological analysis of the inflamed joints from mice with CIA was performed using microcomputed tomography (micro-CT) and hematoxylin-eosin (HE) staining. RNA sequencing (RNA-Seq), network pharmacology analysis, molecular docking, drug affinity responsive target stability (DARTS) assay, and cellular thermal shift assay (CETSA) were performed to evaluate the targets of IPRN.

RESULTS

IPRN ameliorated the inflammatory phenotype of RA FLSs by inhibiting their cytokine production, migration, invasion, and proangiogenic ability. IPRN also significantly reduced the severity of CIA in mice by decreasing paw thickness, arthritis score, bone damage, and serum inflammatory cytokine levels. A mechanistic study demonstrated that macrophage migration inhibitory factor (MIF), a key protein in the inflammatory process, was the specific target by which IPRN exerted its anti-inflammatory effects in RA FLSs.

CONCLUSION

Our study demonstrates the antiarthritic effect of IPRN, which suggests the therapeutic potential of IPRN in RA.

Effect of Eriodictyol on Collagen-Induced Arthritis in Rats by Akt/HIF-1α Pathway

Purpose

The aim of the experiment was to explore the effect of eriodictyol (ERI) on arthritis.

Methods

We established a rat model of collagen-induced rheumatoid arthritis (CIA) using type II collagen plus Freund’s complete adjuvant. We evaluated the degree of paw swelling, joint pathology, inflammatory cytokine levels, and the Akt/hypoxia-inducible factor (HIF)-1α signaling pathway in the CIA rats.

Results

ERI significantly ameliorated joint swelling; improved joint pathology; and suppressed the release of interleukin-6, interleukin-1 beta, and tumor necrosis factor-alpha. Moreover, ERI inhibited the Akt/HIF-1α pathway in the joints of rats and in lipopolysaccharide-treated RAW264.7 cells.

Conclusion

ERI ameliorated arthritis in a manner involving the Akt/HIF-1α signaling pathway.