COMBINED EFFECTS OF RETINOIC ACID AND SELENIUM ON CELL VIABILITY IN SH-SY5Y NEUROBLASTOMA CELLS

Objective: This study aimed to investigate the individual and combined effects of retinoic acid (RA) and selenium (Se) on cell viability in SH-SY5Y neuroblastoma cells, with a focus on dose- and time-dependent responses.Materials and Methods: SH-SY5Y cells were treated with varying concentrations of RA (1, 10, or 100 μM) and Se (1, 10, or 100 μM), either alone or in combination. Cell viability was assessed using the trypan blue exclusion assay at 48 and 72 hours. Statistical analyses were performed using one-way or two-way ANOVA followed by Dunnett’s post hoc test, as appropriate.Results: Retinoic acid significantly reduced cell viability in a dose-dependent manner at both time points, with 100 μM RA causing near-complete loss of viable cells. Selenium also decreased viability, but its effect was milder and became significant only at higher concentrations. Notably, the combined application of RA and Se produced a substantially stronger cytotoxic effect than either agent alone, indicating a potential synergistic or additive interaction between the two.Conclusion: These findings indicate that the simultaneous application of RA and Se can elicit a stronger cytotoxic effect in SH-SY5Y cells than either treatment alone. The results highlight the importance of redox modulation and combination strategies in neuroblastoma cell models. Further studies are warranted to elucidate the underlying mechanisms and therapeutic potential of RA and Se co-treatment.