Sulforaphane-Mediated Multitarget Therapeutic Effects in Methylmercury-Induced ALS-Like Pathology: Comparative...

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder marked by motor neuron loss driven by oxidative stress, neuroinflammation, and dysregulated survival signaling. The objective of this study was to evaluate the neuroprotective efficacy and safety of sulforaphane (SUFP) in a methylmercury (MMHg⁺)-induced preclinical rat model of ALS, with comparison to omaveloxolone (OVX) and dimethyl fumarate (DIMT). SUFP treatment, particularly at 4 mg/kg, significantly restored antioxidant defense mechanisms through upregulation of Nrf2, HO-1, and SIRT1 while suppressing pro-inflammatory cytokines (IL-1β, TNF-α), apoptotic markers (Bax, caspase-3), and stress-related signaling pathways including p75NTR, PI3K/Akt, and MAPKs. These molecular effects translated into meaningful functional recovery, as evidenced by improvements in grip strength, locomotor performance, spatial memory, and depressive-like behavior. Histopathological evaluation demonstrated attenuation of demyelination and preservation of neuronal architecture in cortical, hippocampal, and cerebellar regions. Beyond central neuroprotection, SUFP exerted systemic benefits by normalizing hepatic enzymes, improving skeletal muscle integrity, restoring redox balance, stabilizing neurofilament and myelin-associated proteins, and correcting hematological alterations. Comparative analysis revealed that SUFP conferred superior neuroprotection with a favorable safety profile relative to OVX and, although slightly less efficacious than DIMT, exhibited reduced systemic toxicity. Molecular docking further supported SUFP's interaction with Nrf2-Keap1 targets, reinforcing its antioxidant and anti-inflammatory mechanisms. Collectively, these findings identify SUFP as a multifaceted and well-tolerated therapeutic candidate for ALS, supporting its further translational and clinical evaluation.