Repositioning Propranolol for Neuroimmune Modulation: A Molecular Perspective on Glial Inflammation and Autophagy via Integrated In Vitro and Computational Approaches

Propranolol, a non-selective β-blocker, exerts anti-inflammatory and neuroprotective effects beyond cardiovascular use. However, its role in autophagy remains unclear, despite the relevance of autophagy to neuroinflammatory conditions such as Parkinson's disease. This study integrated in vitro and in silico approaches to explore propranolol's potential modulation of autophagy-related signaling in enteric glial cells (EGCs) under inflammatory stress. EGCs, the representatives of brain astrocytes, were treated with rotenone (10 μM) to induce inflammation, ±propranolol co-treatment (10 and 50 μM). Cell viability was assessed by MTT assay, and expression of glial activation markers (GFAP, S100B) and the autophagy-related gene BECN1 was quantified by RT-qPCR. In silico analyses included SwissTargetPrediction, STRING-based enrichment, and molecular docking against canonical autophagy regulators (BECN1-MTOR-ATG5-ATG7-LC3B). Rotenone significantly increased GFAP and S100B expression, confirming robust glial activation, whereas propranolol markedly attenuated these increases, indicating a clear anti-inflammatory effect. In contrast, propranolol reduced BECN1 expression both alone and in combination with rotenone, suggesting suppression of autophagy initiation rather than restoration of autophagic signaling. Network analyses revealed no direct overlap between propranolol targets and autophagy-related proteins, although several propranolol targets are upstream regulators of autophagy. Docking analyses demonstrated relatively favorable LC3B interaction, although this binding remained weaker than the reference. However, LC3 mRNA expression was undetectable, and docking scores for the other autophagy proteins were modest. These findings suggest propranolol modulates glial activation mainly via autophagy-independent mechanisms, with only limited potential for direct autophagy modulation. In this context, propranolol appears to exert context-dependent neuromodulatory effects on EGCs, warranting further investigation of its potential relevance in modulating neuroinflammatory pathways.