Cibotii Rhizoma extract protects rat dorsal root ganglion neurons against H2O2-induced oxidative stress

초록

Background Dorsal root ganglion (DRG) neurons are particularly susceptible to oxidative injury, which contributes to neuronal apoptosis and altered pain signaling. Oxidative stress in DRG neurons plays a pivotal role in the onset and maintenance of pain hypersensitivity under pathological conditions. We aimed to investigate the neuroprotective effects of Cibotii Rhizoma (CR) in rat DRG neurons subjected to H2O2-induced oxidative stress. Methods Primary DRG neurons were isolated from 5-week-old Sprague-Dawley rats and cultured under short-term and long-term protocols. Cells were treated with CR (10-400 mu g/mL) and exposed to H2O2. Cell viability was assessed by Cell Counting Kit-8 assay, and antioxidant effects were evaluated via DCFDA and MitoSOX-based flow cytometry and immunocytochemistry. Neurite outgrowth was analyzed using Tuj1 staining, and pain-related markers (CGRP, IB4, TRPV1, and substance P) were examined in long-term cultures. Molecular docking was performed to assess TRPV1 binding affinity of CR-derived compounds. Results CR showed no cytotoxicity up to 400 mu g/mL and significantly protected DRG neurons from 10 mu g/mL against H2O2-induced oxidative stress. CR promoted neurite outgrowth and reduced oxidative stress markers (DCFDA(+) and MitoSOX(+) cells) within the 10-50 mu g/mL concentration range, dose-dependently. Pain-related proteins (CGRP, IB4, TRPV1) and substance P were upregulated by H2O2 but significantly decreased following CR treatment. Molecular docking identified several CR-derived compounds with high binding affinity to TRPV1 may attenuate pain signaling pathways. Conclusions CR confers neuroprotection against oxidative stress in DRG neurons and modulates pain-related signaling pathways, highlighting its potential as a therapeutic agent for oxidative stress-induced neuropathic pain.

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