Formononetin attenuates skeletal muscle atrophy induced by gastric cancer cachexia

Formononetin (FMN) is a bioactive compound found in traditional Chinese medicinal plants, including red clover and Astragalus membranaceus. FMN has demonstrated anti-inflammatory effects and the promotion of myogenic differentiation. However, its role and precise mechanisms in muscle atrophy caused by gastric cancer (GC) cachexia remain unexplored. GC cachexia model was established by subcutaneous inoculation of MKN45 into BALB/c nude mice. Body weight and food intake were monitored every other day. Muscle function was assessed using grip strength meter. In vitro, C2C12 myotube atrophy model was created by TNF-α. Myotube atrophy was assessed using immunofluorescence staining for myosin heavy chain (MHC) to evaluate morphological changes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis predicted FMN’s mechanisms. Western blotting validated signaling proteins. Administration of FMN attenuated body weight loss and muscle wasting in tumor-bearing nude mice, while also improved grip strength. Similarly, FMN attenuated atrophy in C2C12 myotubes, as evidenced by the downregulation of the atrophy marker Muscle RING-Finger Protein-1 (MURF1) and the upregulation of the myogenic regulator Myogenic Differentiation (MYOD). Mechanistically, FMN promoted PI3K/AKT/mTOR phosphorylation, activating anabolic pathways for muscle growth. It also suppressed autophagy by reducing LC3-II/LC3I, Beclin1 and elevating p62, thereby inhibiting muscle catabolism. FMN is a potentially promising therapeutic candidate for the treatment of muscle atrophy caused by GC cachexia. FMN effectively alleviates muscle atrophy by activating the PI3K-AKT-mTOR pathway and inhibiting autophagy.