Bu-zhong-yi-qi decoction regulates JNK/c-JUN signaling pathway to improve skeletal muscle atrophy caused by cancer cachexia

ETHNOPHARMACOLOGICAL RELEVANCE: With a prevalence reaching 80 % in terminal cancer patients, cancer cachexia (CC) manifests as irreversible skeletal muscle wasting. Presently, there exists no effective therapeutic strategy for managing cancer cachexia. Traditional Chinese medicine (TCM) contributes significantly to the management of CC, enhancing quality of life and potentially prolonging survival in affected patients. Bu-zhong-yi-qi decoction (BYD), a classical Chinese formulation, demonstrates therapeutic potential for tumor-associated conditions and muscle-related disorders. However, its precise pharmacological mechanisms remain to be fully elucidated. AIM OF THE STUDY: This study aims to systematically investigate the therapeutic effects and underlying mechanisms of BYD on muscle atrophy caused by CC through an integrated approach combining network pharmacology analysis with comprehensive in vivo and in vitro experimental validation. MATERIALS AND METHODS: Network pharmacology analysis was employed to recognize‌ bioactive components, potential therapeutic targets, and associated pathways of BYD. Molecular docking simulations were subsequently performed to evaluate the binding affinity between BYD constituents and key target proteins. The skeletal muscle atrophy model of CC in vivo was established by subcutaneous injection of Lewis lung cancer (LLC) cells. The therapeutic efficacy of BYD was systematically evaluated through a comprehensive assessment of multiple parameters, including carcass weight, gastrocnemius muscle mass, histopathological alterations, the cross-sectional area (CSA) of muscle fibers and inflammatory markers. The muscle atrophy model in vitro was established by C2C12 mouse myoblasts and LLC cells to investigate the underlying mechanisms of BYD. qRT-PCR and Western blot analysis were employed to evaluate the regulatory effects of BYD on both mRNA and protein expression levels of MuRF-1, Atrogin-1 and key molecular components of the JNK/c-JUN signaling pathway. RESULTS: Network pharmacology analysis identified 146 bioactive components and 331 corresponding potential targets of BYD. KEGG pathway enrichment analysis revealed significant enrichment of BYD component targets in the MAPK signaling pathway. Molecular docking simulations revealed strong binding affinities between BYD's bioactive components and JUN protein. Experiments in vivo demonstrated that BYD could increase the carcass weight, gastrocnemius muscle mass and CSA of muscle fibers in mice with cachexia. Meanwhile, it could increase C2C12 myotube diameters in vitro. Additionally, BYD down-regulated the mRNA and protein expressions of MuRF-1, Atrogin-1 and JNK/c-JUN signaling pathway in vivo. CONCLUSIONS: BYD might contribute to ameliorate muscle atrophy induced by CC through suppression of JNK/c-JUN signaling pathway and downregulation of muscle atrophy markers MuRF-1 and Atrogin-1. These findings suggested BYD as a potential therapeutic intervention for CC.