Network pharmacology combined with experimental validation show that apigenin as the active ingredient of Campsis grandiflora flower against Parkinson’s disease by inhibiting the PI3K/AKT/NF-κB pathway

The exploration of novel natural products for Parkinson's disease (PD) is a focus of current research, as there are no definitive drugs to cure or stop the disease. Campsis grandiflora (Thunb.) K. Schum (Lingxiaohua) is a traditional Chinese medicine (TCM), and the exact active constituents and putative mechanisms for treating PD are unknown. Through data mining and network pharmacology, apigenin (APi) was identified as the main active ingredient of Lingxiaohua, and key targets (TNF, AKT1, INS, TP53, CASP3, JUN, BCL2, MMP9, FOS, and HIF1A) of Lingxiaohua for the treatment of PD were discovered. The primary routes implicated were identified as PI3K/AKT, Apoptosis, TNF, and NF-κB pathways. Subsequently, therapeutic potential of APi in PD and its underlying mechanism were experimentally evaluated. APi suppressed the release of mediators of inflammation and initiation of NF-κB pathways in MES23.5 cells induced by MPP+. APi suppressed caspase-3 activity and apoptosis and elevated p-AKT levels in MES23.5 cells. Pretreatment with LY294002, a PI3K inhibitor, resulted in APi treatment blocking the activation of NF-κB pathway and expression of inflammatory factors in MES23.5 cells by activating the PI3K/AKT pathway. In conclusion, APi protects dopaminergic neurons by controlling the PI3K/AKT/NF-κB pathway, giving novel insights into the pharmacological mechanism of Lingxiaohua in treating PD.