Liquiritin in Chaihu-shugan-san alleviates Parkinson's Disease via PPARα-mediated inhibition of SCD1/FADS2-dependent Ferroptosis

Abstract

Background

Parkinson's disease (PD) is a progressive neurodegenerative disorder with increasing global prevalence. Chaihu-shugan-san (CSS) is a Chinese medicine compound with reported neuroprotective properties. However, the precise bioactive constituents and underlying mechanisms of CSS in the context of PD remain poorly defined.

Purpose

This study aimed to systematically evaluate the therapeutic potential of CSS, characterize its bioactive constituents, and elucidate the potential molecular mechanisms in PD.

Methods

A network pharmacology-bioinformatics framework was established to predict the potential targets of CSS in PD. MPTP-induced PD mouse models were validated by behavioral tests, histopathology (HE staining), immunohistochemistry (IHC), and Western blot (WB). Machine learning and ROC curve analysis pinpointed key ferroptosis-related genes linked to CSS and PD, with functional enrichment highlighting possible pathways. Further validation was performed using IHC, GPx, MDA, and WB assays. UPLC-MS/MS was employed to characterize bioactive CSS components, followed by druggability screening, molecular docking, and molecular dynamics (MD) simulations. In vitro, MES23.5 cells exposed to MPP⁺ were used to evaluate the neuroprotective effects of Liquiritin (LIQ), the principal active compound in CSS, via CCK-8, LDH, oxidative stress markers (GPx, MDA), lipid peroxidation (C11-BODIPY), iron accumulation (FerroOrange), and WB. Additional validation of ferroptosis modulation was performed in vivo and in vitro.

Results

Multidisciplinary investigations employing prediction and experimental validation consistently demonstrated the neuroprotective effects of CSS against MPTP-induced PD mouse. Machine learning, ROC curve analysis and in vivo validation identified CSS ameliorates PD by inhibiting ferroptosis through PPARα activation. Intriguingly, CSS exhibited therapeutic potential by counteracting ferroptosis-triggered PD-like pathological manifestations in mice. Integrated analysis involving UPLC-MS/MS, druggability screening, molecular docking and MD simulations demonstrated LIQ to be a core bioactive compound in CSS. Mechanistic studies revealed that LIQ protects against MPP⁺- or erastin-induced ferroptosis in MES23.5 cells via activation of the PPARα/SCD1/FADS2 pathway. Pharmacological inhibition of PPARα abolished LIQ's protective effects against both ferroptosis and PD progression, definitively establishing PPARα activation as essential for LIQ-mediated neuroprotection.

Conclusion

LIQ, a major bioactive component of CSS, ameliorates PD pathology by inhibiting ferroptosis through activation of the PPARα/SCD1/FADS2 signaling pathway. These findings uncover a novel anti-ferroptosis mechanism and provide a promising therapeutic framework for the prevention and treatment of PD.