A Ternary Flavonoid Formulation Mitigates Fractional Radiation-Induced Brain Injury via Transcriptomic Reprogramming and Synaptic Protection.

UNLABELLED: Fractional ionizing radiation (FIR) is a standard cancer therapy but often induces severe central nervous system complications, including cognitive decline and physiological dysfunction. While natural flavonoids hold therapeutic promise for radiation-induced brain injury (RIBI), optimizing their combinations and elucidating the underlying molecular pathways remain challenging.

METHODS: To develop a precise therapeutic strategy, we first integrated network pharmacology and UHPLC-Q-Orbitrap MS/MS analysis to identify three highly effective flavonoid monomers from a radioprotective botanical extract. Subsequently, an in vivo anti-inflammatory screening was conducted to determine the optimal combinatorial ratio, designated as the ternary formulation QLI. The neuroprotective efficacy of QLI was then systematically evaluated in a mouse model of fractional RIBI (cumulative dose of 12 Gy) through behavioral assessments, hematopoietic profiling, and neurotransmitter analyses. Transcriptomic alterations were explored via RNA-sequencing (RNA-seq) and validated by molecular docking, RT-qPCR, and Western blotting.

RESULTS: Pharmacological and mass spectrometry analyses identified Quercetin, Luteolin, and Isorhamnetin-3-O-glucoside as the core bioactive monomers. Quantitative synergistic screening established the optimal QLI formulation at a mass ratio of 2:1:1. In vivo, FIR exposure induced severe spatial memory deficits, disrupted neurotransmitter homeostasis, and caused hematopoietic decline. Administration of QLI successfully reversed these physiological and cognitive impairments. Transcriptomic profiling revealed that QLI globally reprogrammed aberrant gene expression, specifically normalizing signaling networks related to the PI3K-Akt pathway, apoptosis, and neuroactive ligand-receptor interactions. Multidimensional validation confirmed that QLI mitigated neuroinflammation, suppressed astrocyte hyperactivation (GFAP), and preserved synaptic plasticity by preventing the pathological accumulation of SynGAP and autophagic stress (Beclin-1).

CONCLUSIONS: The rationally designed ternary flavonoid formulation (QLI) provides potent neuroprotection against fractional RIBI. By resolving neuroinflammation, alleviating synaptic plasticity suppression, and normalizing stress-induced transcriptomic disruptions, QLI represents a promising multi-target experimental formulation with the potential to mitigate radiotherapy-associated neurological side effects.