Study Design: Pre‐clinical animal experiment.Objective: In this study, we investigated therapeutic effects of silibinin in a spinal cord injury (SCI) model. In SCI, loss of cells due to secondary damage mechanisms exceeds that caused by primary damage. Ferroptosis, which is iron‐dependent non‐apoptotic cell death, is shown to be influential in the pathogenesis of SCI.Methods: The study was conducted as an in vivo experiment using a total of 78 adult male/female Sprague Dawley rats. Groups were as follows: Sham, SCI, deferoxamine (DFO) treatment, and silibinin treatment. There were subgroups with follow‐up periods of 24 h, 72 h, and 6 weeks in all groups. Malondialdehyde (MDA), glutathione (GSH), and Fe²⁺ levels were measured by spectrophotometry. Glutathione peroxidase‐4 (GPX4), ferroportin (FPN), transferrin receptor (TfR1), and 4‐hydroxynonenal (4‐HNE)‐modified protein levels were assessed by Western blotting. Functional recovery was assessed using Basso–Beattie–Bresnahan test.Results: Silibinin achieved significant suppression in MDA and 4‐HNE levels compared to the SCI both in 72‐h and 6 weeks group (p < 0.05). GSH, GPX4, and FNP levels were found to be significantly higher in the silibinin 24 h, 72 h, and 6 weeks group compared to corresponding SCI groups (p < 0.05). Significant reduction in iron levels was observed in silibinin treated rats in 72 h and 6 weeks group (p < 0.05). Silibinin substantially suppressed TfR1 levels in 24 h and 72 h groups (p < 0.05). Significant difference among recovery capacities was observed as follows: Silibinin > DFO > SCI (p < 0.05).Conclusion: Impact of silibinin on iron metabolism and lipid peroxidation, both of which are features of ferroptosis, may contribute to therapeutic activity. Within this context, our findings posit silibinin as a potential therapeutic candidate possessing antiferroptotic properties in SCI model. Therapeutic agents capable of effectively and safely mitigating ferroptotic cell death hold the potential to be critical points of future clinical investigations.

Study Design.: Experimental animal study investigating the efficacy of C-terminal domain of tetanus toxin application as neuroprotective effects on rat brain in a model of spinal cord injury (SCI). Objective.: The aim of the present study was to investigate the possible role of C-terminal domain of tetanus toxin (Hc-TeTx) on cell death mechanisms including apoptosis and autophagy following SCI. Summary of Background Data.: Traumatic SCI can lead to posttraumatic inflammation, oxidative stress, motor neuron apoptosis, necrosis, and autophagy of tissue. To promote and enhance recovery after SCI, recent development of devices and therapeutic interventions are needed. Methods.: Twenty-eight adult rats were divided into four groups (n = 7 each) as follows: sham, trauma (SCI), SCI + Hc-TeTx, and SCI + methylprednisolone groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the Basso, Beattie and Bresnahan (BBB) open-field locomotor test. The alterations in pro-/anti-apoptotic and autophagy related-protein levels were measured by Western blotting technique. Results.: In this study, Hc-TeTx promotes locomotor recovery and motor neuron survival of SCI rats. Hc-TeTx also decreased expression of bax, bad, bak, cleaved caspase-3, Ask1, and autophagy-related proteins including Atg5 and LC3II in brain. Our study provides an evidence that cell death mechanisms play critical roles in SCI and that the nontoxic peptides including Hc-TeTx may exert protective effect and decrease cell death following SCI. Conclusion.: Our preliminary findings suggest a possible therapeutic agent to improve survival after spinal cord trauma, but further analysis are still needed to evaluate the difference between acute and chronic injuries. Level of Evidence: N/A

Neuromelanin (NM) is an iron-rich, insoluble brown or black pigment that exhibits protective properties. However, its accumulation over time may render it a source of free radicals. In Parkinson's disease, dopaminergic neurons with the highest NM levels and increased iron content are preferentially vulnerable to degeneration. Considering NM's iron binding capacity and the critical role of iron in ferroptosis, we aimed to investigate the interplay between neuromelanin and ferroptosis in dopaminergic cells. We prepared two NM pigments: iron-free NM (ifNM) and iron-containing NM (Fe³⁺NM) and, exposed to cells. After verifying NM accumulation, cell viability was assessed in the absence or presence of antioxidants (NAC (1 mM), Trolox (100 μM)) and specific inhibitors of cell death types. Ferroptosis-related parameters, including lipid peroxidation byproducts (4-HNE), lipid ROS, glutathione, intracellular iron, GPX4, and ACSL4, and cellular iron metabolism-related proteins (TfR1, ferroportin, ferritin, IREB2) were evaluated following ifNM and Fe³⁺NM treatments, with or without Ferrostatin-1, Liproxstatin-1 and deferoxamine. Both NMs induced cell death via distinct mechanisms. Ferroptotic cell death by ifNM and Fe³⁺NM was reversed by ferrostatin-1 and NAC (p < 0.05). Significant alterations in lipid peroxidation, GPX4 levels, and iron metabolism were observed independent of NM's iron composition (p < 0.05). Ferritin levels increased following ifNM treatment, reflecting an adaptive response to iron overload, while Fe³⁺NM treatment led to ferritin depletion, possibly via ferritinophagy. Our findings reveal a distinct role of iron-rich and iron-free neuromelanin in modulating ferroptotic pathways, highlighting the potential of targeting neuromelanin-iron interactions as a therapeutic strategy to mitigate neuronal ferroptosis in Parkinson's disease.