Cayratia albifolia C.L.Li exerts anti-rheumatoid arthritis effect by inhibiting macrophage activation and neutrophil extracellular traps (NETs)

Abstract

Background Cayratia albifolia C.L.Li (CAC), commonly known as “Jiao-Mei-Gu” in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established. Methods Twenty-four Sprague–Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot. Results CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA. Conclusions We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation. Graphical Abstract