5-methoxyflavone promotes functional recovery of spinal cord injury by competitively inhibiting adenosine A1 receptor-induced neuroinflammation.

Abstract

On account of inconsistent efficacy, significant adverse effects, and prohibitive treatment costs of current therapeutic interventions in spinal cord injury (SCI), it is an urgent need to develop novel therapeutic strategies that are more effective, safer, and economically viable. 5-Methoxyflavone (5-MF) has shown promising efficacy in cancer and inflammatory disease models. However, its therapeutic potential in SCI remains largely unexplored. Thus, the aim of the present study was to characterize the precise mechanism of action of 5-MF on the SCI. In this study, we used a rat model of SCI to evaluate the therapeutic efficacy of 5-MF on motor function recovery. We found that 5-MF significantly improved locomotor function in rats with SCI and attenuated spinal cord edema and inflammatory cell infiltration. Importantly, 5-MF competitively bound to the adenosine A1R receptor, leading to potent suppression of pro-inflammatory cytokine expression-including IL-6, IL-1β, IL-18, and TNF-α-within activated astrocytes. Simultaneously, 5-MF treatment markedly reduced neuronal apoptosis, which was mechanistically linked to the downregulation of PI3K-Akt signaling pathway activity and concomitant inhibition of the ZAC1/p53 transcriptional axis. These findings delineated that 5-MF, as a putative adenosine A1R receptor antagonist, mitigates neuronal damage and facilitates functional recovery after SCI by suppressing the PI3K-Akt-ZAC1/p53 signaling cascade, which is a critical pathway driven by neuroinflammation. This study establishes a novel therapeutic paradigm for SCI and underscores the clinical significance of 5-MF.