Systems pharmacology and targeted transcriptional profiling suggest the putative neuroprotective role of Leuconostoc mesenteroides in an in vitro Alzheimer's disease model.

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder driven by amyloid-beta (Aβ) accumulation, mitochondrial failure, and neuroinflammation. While probiotics show therapeutic potential via the gut brain axis, the molecular mechanisms remain poorly understood. This study investigated the neuroprotective potential of Leuconostoc mesenteroides lysate and its bioactive metabolites in an Aβ-induced SH-SY5Y neuroblastoma model.

METHODS

SH-SY5Y cells were challenged with Aβ and treated with L. mesenteroides lysate. Neuroprotective effects were evaluated via ROS accumulation, SOD1, APOE, NOS2, and mitochondrial dynamics (MFF, OPA1) using qPCR and WB. Potential mechanisms of action were explored computationally through integrated genome mining (antiSMASH 7.0), molecular docking (CB-Dock2), and systems pharmacology analysis (STRING/KEGG/R-studio) to identify candidate metabolites and host targets.

RESULTS

L. mesenteroides lysate significantly attenuated Aβ-induced ROS levels and upregulated SOD1, enhancing antioxidant capacity. The lysate effectively downregulated APOE expression and restored mitochondrial homeostasis by reducing mitochondrial fission (MFF) and promoting fusion (OPA1). In silico analysis predected phytoene as a primary bioactive metabolite with significant theoretical binding affinity for APOE. Systems biology mapping revealed highly significant enrichment in PPAR signaling and cholesterol metabolism pathways (FDR < 10⁻⁵). Specifically, Cellular Component analysis highlighted robust interactions within protein-lipid complexes (FDR = 1.98e-16).

CONCLUSION

L. mesenteroides lysate counteracts Aβ-induced neurotoxicity by modulating oxidative stress and restoring mitochondrial bioenergetics. Collectively, our findings suggest a theoretical Phytoene-PPAR-APOE signaling axis as a predictive framework for the observed cellular effects. We emphasize that phytoene represents a predicted candidate metabolite requiring future chemical characterization and biological validation.