Jinwu Jiangu capsule attenuates rheumatoid arthritis via the SLC7A11/GSH/GPX4 pathway in M1 macrophages

Background: JinWu JianGu capsule (JWJGC) is a Chinese herbal medicine that alleviates the clinical manifestations of rheumatoid arthritis (RA). However, the mechanism of action requires further investigation..

Purpose: This study aimed to investigate the anti-inflammatory effects of JWJGC on RA via the regulation of reactive oxygen species (ROS) and ferroptosis.

Materials and methods: JWJGC was administered to rats with collagen-induced arthritis (CIA) via oral gavage for 28 days. In vitro, M1 macrophages were pre-treated with JWJGC-containing serum. After assessing joint swelling and physiologic, the M1/M2 macrophage ratio was detected in CIA rats. The levels of ROS markers were assessed in the serum and cell supernatants. Liquid chromatography-tandem mass spectrometry analyses were employed to check lipid metabolism, and changes in mitochondrial morphology during ferroptosis were detected by transmission electron microscopy. Western blotting, immunofluorescence, immunohistochemistry, and qRT-PCR were performed to validate these results.

Results: JWJGC ameliorated CIA by reducing ROS levels in rats. It also restored the balance of the M1/M2 macrophage ratio and reduced the levels of macrophage-related inflammatory markers. Additionally, JWJGC affected lipid metabolism to alleviate inflammation by downregulating lipids associated with ferroptosis. It attenuated ferroptosis by modulating glutathione (GSH)/ Glutathione peroxidase 4(GPX4) expression in CIA rats. In vitro, JWJGC targeted M1 macrophages via the solute carrier family 7a member 11 (SLC7A11)/GSH/GPX4 signaling pathway.

Conclusions: This study showed that JWJGC improved RA, primarily through the integrated regulation of the SLC7A11/GSH/GPX4 pathway in M1 macrophages. These findings provide an innovative therapeutic basis for RA treatment and expanding the clinical applications of JWJGC.