Metabolomics and Network Pharmacology Analyses Reveal the Mechanism of Moxibustion in Knee Osteoarthritis.

Background: This study aimed to explore the mechanism of moxibustion in the knee by combining osteoarthritis metabolomics and network pharmacology.

Methods: A rat knee osteoarthritis (KOA) model was established by intra-articular injection of papain. The efficacy of moxibustion in KOA rats was evaluated by swelling degree, pathological progress, and mobility loss of knee joint. On this basis, the metabolic mechanism of moxibustion in relieving knee osteoarthritis was analyzed by metabolomics analysis.

Results: Moxibustion significantly reduced joint swelling and inflammation in the knee joint of KOA rats. Sixteen metabolites and nine metabolic pathways were found to be associated with the mechanism of action of moxibustion in metabolomics analysis results. According to network pharmacology, 3186 KOA disease targets, 158 drug targets, and 89 intersecting targets were obtained. The key targets included MAPK-3, AKT-1, RELA, MAPK-8, MAPK-14, etc. Signal pathways were found to be involved in mechanisms of moxibustion in knee osteoarthritis, such as alanine, aspartate, and glutamate metabolism, cysteine and methionine metabolism, and arginine and proline metabolism.

Conclusion: The mechanism of moxibustion in knee osteoarthritis may involve alanine, aspartate, and glutamate metabolism, cysteine and methionine metabolism, arginine and proline metabolism, amino tRNA biosynthesis, and D-glutamine and D-glutamate metabolism signaling pathways with MAPK-3, AKT-1, RELA, MAPK-8, and MAPK-14 as core targets. More precise mechanisms need to be verified by further systematic molecular biology experiments.