Mechanism of Lycopodii herba for RA-ILD using integrated metabolomics and network pharmacology

Interstitial lung disease (ILD) is the most common complication of rheumatoid arthritis (RA), which highly increases the morbidity and mortality of RA. Lycopodii herba (SJC) has been used as a widespread traditional Chinese medicine to treat RA and the related complications for more than 500 years. However, its therapeutic effect on RA-ILD and related mechanisms are not clear. The purpose of this work was to confirm the efficacy of SJC for RA-ILD and clarify its mechanism. In this study, we first determined the efficacy of SJC on RA-ILD. Then, 15 potential biomarkers of SJC were identified by metabolomics in rat serum, which were mainly associated with ether lipid metabolism and arachidonic acid metabolism. 21 pathways were related to SJC by network pharmacology. Combined with the results of metabolomics and network pharmacology and real-time PCR (RT-PCR) validation, the mechanism of SJC for RA-ILD may be related to the Ras signaling pathway and PI3K-Akt signaling pathway by regulating the expression of PLA2G1B and PI3KCA. This work preliminary confirmed the preventive and therapeutic effects of SJC on RA-ILD and elucidated the mechanism from the metabolic perspective.