Cordycepin mitigates MPTP-induced Parkinson's disease through inhibiting TLR/NF-κB signaling pathway

Parkinson's disease (PD) is a neurodegenerative disease with movement disorder. PD is characterized by the loss of dopaminergic (DA) neurons in the substantia nigra. Cordycepin, a small molecule extracted from cordyceps sinensis, has neuroprotective, anti-inflammatory, antioxidant and anti-tumor properties. In this study, we explored its possible beneficial effects on PD. PD rat models and cell models were established via 1‑methyl‑4‑phenyl‑1,2,3,6‑tetrahydropyridine (MPTP) injection and LPS treatment respectively, and cordycepin was administered. The motor functions of rats were examined, and the tyrosine hydroxylase (TH)-positive DA neurons and Iba1-positive microglia were detected by immunohistochemical and immunofluorescence staining. The expression levels of inflammatory and oxidative stress-related factors were also measured in vivo and in vitro. In addition, the TLR/NF-κB pathway was investigated to explore the mechanism. We found that in vivo, MPTP injection introduced motor disorders, the loss of DA neurons and the activation of TLR/NF-κB signaling pathway. Cordycepin treatment alleviated these MPTP-induced changes. In vitro, the results were confirmed in Lipopolysaccharide (LPS)-induced cells. Moreover, cordycepin mitigated the cytotoxic effects on PC12 cells produced by microglia. In conclusion, cordycepin alleviated PD symptoms by inhibiting TLR/NF-κB signaling pathway in vivo and in vitro.