Identification of Kaempferol for Skeletal Muscle Wasting in Cancer Cachexia Through Bibliometric Analysis and Network Pharmacology: Metabolomic and Experimental Evaluation

Abstract

Cancer cachexia (CC) is a multifactorial syndrome characterized by progressive skeletal muscle wasting, systemic inflammation, and metabolic dysregulation. Traditional Chinese medicine (TCM) contains numerous bioactive compounds with potential multitarget effects, but systematic strategies for identifying and experimentally evaluating candidate compounds for CC remain limited. This study aimed to identify and evaluate a TCM-derived candidate compound for CC-associated skeletal muscle wasting. Bibliometric analysis was used to identify frequently studied TCM formulas and core herbs in cachexia-related research, followed by network pharmacology analysis of candidate compounds and associated pathways. Kaempferol (KA) was then evaluated in A549 tumor-bearing mice by assessing tumor burden, cachexia-related phenotypes, skeletal muscle histology, untargeted metabolomics, inflammatory mediators, muscle degradation-related markers, autophagy-associated endpoints, and ultrastructure. A549-conditioned medium (A549-CM)-treated C2C12 myotubes were used for complementary in vitro evaluation under conditions with or without supplemental prostaglandin E2 (PGE2). KA was selected as a representative candidate based on its distribution among the core herbs, network associations, and reported pharmacological activities. In A549 tumor-bearing mice, high-dose KA (100 mg/kg/day) significantly reduced tumor weight and was accompanied by improvements in food intake, estimated tumor-free body weight, gastrocnemius weight, myofiber cross-sectional area, and forelimb grip strength compared with the model group (all P < 0.05). KA treatment was also associated with lower serum TNF-α, IL-6, and PGE2 concentrations; reduced skeletal muscle COX-2, Atrogin-1, and MuRF1 expression; lower LC3B-II/LC3B-I ratio and p62 protein level; and fewer autophagic vacuole-like structures (all P < 0.05). Untargeted metabolomics revealed KA-associated alterations in arachidonic acid metabolism, glycerophospholipids, amino acids, and energy-related metabolites. In A549-CM-treated C2C12 myotubes, KA modulated atrophy-related gene expression, autophagy-associated endpoints, and cytoplasmic vacuolation in both the absence and presence of supplemental PGE2 ( P < 0.05). KA reduced tumor burden and was accompanied by improvements in cachexia-related phenotypes and skeletal muscle outcomes. The molecular, metabolic, and cell-based findings further associated KA treatment with lower systemic inflammatory mediator levels, reduced muscle protein degradation-related markers, and alterations in inflammatory lipid metabolism and autophagy-associated endpoints. These findings support further investigation of KA as a TCM-derived candidate for CC-associated skeletal muscle wasting. Future studies should distinguish its direct muscle-related effects from the systemic benefits associated with reduced tumor burden and clarify whether KA alters PGE2-related signaling and autophagic flux.