Prenanthes purpurea and 3,5-DiCQA Alleviate Cellular Stress in H₂O₂-Induced Neurotoxicity: An In Vitro Comparative Study

Oxidative stress exerts multiple disruptive effects on cellular morphology and function and is a major detriment to age-related and pathological neurodegenerative processes. The present study introduces an evaluative and comparative investigation of the antioxidant and cytoprotective properties of a Prenanthes purpurea extract and its major constituent 3,5-dicaffeoylquinic acid (DiCQA) in an in vitro model of H₂O₂-induced neurotoxicity. Using validated in vitro and in silico approaches, we established the presence and concentration dynamics of cellular protection in a 24 h pretreatment regimen with the natural products. The conducted cytotoxicity studies and the automated Chou-Talalay analysis for studying drug interactions demonstrated a strong antagonistic effect of the tested substances against oxidative stimuli in an "on demand" manner, prevailing at the higher end of the concentration range. These findings were further supported by the proteomic characterization of the treatment samples, accounting for a more distinct neuroprotection provided by the pure polyphenol 3,5-DiCQA.