Neuroprotective and Antioxidant Activity of Newly Synthesized N-Pyrrolyl Hydrazide-Hydrazones in Experimental Models of Neurotoxicity In Vitro and In Vivo

Oxidative stress plays a central role in the pathogenesis of neurodegenerative disorders, including Parkinson’s disease. Therefore, compounds with antioxidant and neuroprotective properties represent promising candidates for therapeutic development. N-pyrrolyl hydrazide-hydrazones, a class of pyrrole-based derivatives, have shown promising potential due to their diverse biological activities, including monoamine oxidase-B (MAO-B) inhibition. This study investigated the neuroprotective properties of 10 N-pyrrolyl hydrazide-hydrazones using experimental in vitro and in vivo models of neurodegeneration. The compounds were tested on SH-SY5Y neuroblastoma cells subjected to oxidative stress induced by 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium (MPP+). A battery of in vitro and in vivo experimental methods was used, including cell viability assay, reactive oxygen species (ROS) production, and apoptosis evaluation by quantifying the sub-G0/G1 cell population. In vivo neuroprotective efficacy was further tested in a rotenone-induced Parkinsonism mouse model by analyzing oxidative biomarkers and brain histopathology. Compounds 2, 4, 5, 6, and 10 significantly preserved cell viability in the 6-OHDA-induced toxicity model, while no protection was observed in the MPP+ model. Particularly compound 2 reduced ROS levels and apoptosis in SH-SY5Y cells. In vivo, compound 2 demonstrated strong antioxidant activity by maintaining glutathione levels and reducing lipid peroxidation. Histological analysis confirmed its protective effect against rotenone-induced neuronal damage. These results suggest that N-pyrrolyl hydrazide-hydrazones, especially compound 2, possess significant antioxidant and MAO-B inhibitory properties, supporting their potential as neuroprotective agents.