Mechanisms involved in lobetyolin attenuation of cisplatin-induced gastrocnemius muscle atrophy in the mouse

The chemotherapeutic agent cisplatin for solid tumors frequently induces cancer-associated cachexia characterized by weight loss and decreased skeletal muscle mass. These adverse cisplatin-related symptoms are dose‑limiting, and the ability to counteract drug-initiated muscle atrophy in cancer-associated cachexia remains a pharmacological challenge. The aim of this study was to determine the protective efficacy of lobetyolin, a natural compound derived from Codonopsis pilosula, known to exert antioxidant, anti‑inflammatory, and anti‑apoptotic activities, against cisplatin-induced skeletal muscle wasting and subsequently elucidate a potential underlying molecular mechanism of action using a mouse model. Mice were injected with cisplatin (4 mg/kg, i.p. every other day, 4 doses in total) with concurrent oral lobetyolin (20 or 40 mg/kg daily) for 8 days. Lobetyolin inhibited cisplatin-induced reductions in body weight and grip strength, ameliorated gastrocnemius muscle atrophy, and preserved myofiber cross‑sectional area. Mechanistically, lobetyolin restored superoxide dismutase (SOD) activity and glutathione (GSH) levels while diminishing malondialdehyde (MDA) content in gastrocnemius muscle. Lobetyolin was found to activate the AKT signaling axis as evidenced by enhanced phosphorylation of AKT (Ser473) and FoxO3α (Thr32), which suppressed FoxO3α nuclear translocation and downregulated the E3 ubiquitin ligase Fbx32, thereby diminishing proteasomal protein degradation. Concurrently, lobetyolin normalized the Bax/Bcl‑2 ratio to inhibit myocyte apoptosis. These findings demonstrated that lobetyolin may be considered as a multi‑targeted therapeutic candidate to counteract oxidative injury, protein catabolism, and myocyte apoptosis initiated by cisplatin. Data suggest that lobetyolin’s potential as a safe adjunctive agent against chemotherapy‑induced muscle wasting might involve AKT/FoxO3α pathway.