Modulation of apoptotic pathways by curcumin and resveratrol conveys neuroprotection against rotenone-induced toxicity in SH-SY5Y cells

Aim: This study investigates the neuroprotective properties of the polyphenolic compounds resveratrol and curcumin against rotenone-induced toxicity in SH-SY5Y neuronal cells. Material and Methods: The cytotoxic threshold (LD50) of rotenone was established through a dose-response assessment in SH-SY5Y cells. Cells were pre- incubated with varying concentrations of resveratrol (1-100 mu M) and curcumin (10-1000 nM), followed by a 24-hour rotenone challenge (200 nM). Cell survival was gauged using the MTS assay, while caspase-3 levels, as a marker of apoptosis, were quantified via ELISA. The capability of cells to form colonies post-treatment was determined through a clonogenic survival assay. Moreover, the Western blot analysis revealed that pre-treatment with resveratrol and curcumin significantly modulated the protein expression levels of Bax and Bcl-2. Results: Pretreatment with resveratrol and curcumin significantly enhanced cell viability and clonogenic survival in the presence of rotenone, with notable decreases in caspase-3 levels, implying reduced apoptosis (p < 0.05). These compounds also modulated the expression of Bax and Bcl-2, contributing to their protective effects. Discussion: Resveratrol and curcumin exhibit promising neuroprotective effects by improving cell survival and modulating apoptotic markers in SH-SY5Y cells subjected to rotenone-induced toxicity. These findings support the potential therapeutic role of these polyphenols in neurodegenerative disease management, pending further validation through comprehensive pre-clinical and clinical studies.