Investigation of the effects of pirfenidone in amyloid beta-induced neuroinflammation model in human neuroblastoma cells (SH-SY5Y)

Objective: This study aimed to induce neuroinflammation with amyloid beta in a human neuroblastoma cell culture model and to evaluate the potential neuroprotective and anti-inflammatory effects of pirfenidone in terms of cell viability, apoptosis and inflammatory cytokines. Materials and Methods: The effects of pirfenidone on cell viability and proliferation were assessed using the luminoscan assay; apoptotic effects were evaluated with the Annexin V method; and anti-inflammatory effects were examined using immunocytochemistry. In the study, experimental groups were created as 3, 10, 30, 100 µM pirfenidone, 20 µM amyloid beta, 10 µM pirfenidone + 20 µM amyloid beta and 30 µM pirfenidone + 20 µM amyloid beta. In these experiments, pirfenidone assess its potential to reverse amyloid beta–induced neuroinflammation. Results: Pirfenidone alone did not cause a significant change in cell viability. However, when combined with amyloid beta, it significantly reduced cell viability (p<0.01). Apoptosis analyses showed results parallel to the viability findings: pirfenidone alone did not significantly alter apoptosis, but in combination with amyloid beta, it significantly increased apoptotic cell death (p<0.01). Immunocytochemical evaluations demonstrated that pirfenidone significantly reduced the elevated levels of IL-1β, IL-6, and TGF-β induced by amyloid beta (p<0.01), but cytokine levels did not decline to control group levels (p<0.001). Conclusion: Pirfenidone alone had no effect on the SH-SY5Y cell line. The observation that pirfenidone increases apoptosis while reducing inflammatory cytokines in amyloid beta–treated SH-SY5Y cells indicates a dual effect relevant to neuroinflammation in Alzheimer's disease. While amyloid beta markedly enhances intracellular stress responses and inflammatory cytokine production, pirfenidone suppresses this excessive activation, resulting in significant decreases in IL-1β, IL-6, and TGF-β levels. Considering that neuroinflammation in the human brain is sustained through a cyclical process involving microglia and astrocytes, the regulatory impact of pirfenidone on these pathways may theoretically help reduce chronic inflammatory burden. However, since glial cells also perform protective functions—including amyloid beta clearance and synaptic support—the therapeutic potential of pirfenidone within the complex cellular interactions of brain tissue requires further comprehensive investigation. Keywords: Pirfenidone, amyloid beta, SH-SY5Y, neuroinflammation