Hesperetin reduces neuronal death in an SHSY5Y Alzheimer's model by inhibiting inflammation and apoptosis and pyroptosis cell death pathways.

Alzheimer's disease (AD) features amyloid-β (Aβ)1-42 plaques, neuroinflammation, and neuronal loss. Apoptosis and pyroptosis contribute to AD, with inflammatory cytokines involved. Flavonoids like Hesperetin may reduce Aβ1-42 deposition through anti-inflammatory effects. This study introduces a novel method combining LPS and Aβ1-42 to investigate Hesperetin's mechanism for potential AD treatments. Using computational and experimental methods, we evaluated the physicochemical properties and their correlation with protein aggregation at the molecular level. Human neuroblastoma SH-SY5Y cells were induced to differentiate and then exposed to Hesperetin (1 µM and 10 µM), LPS (1 µg/mL), and Aβ1-42 (20 µM) for 24 h. The expression levels of pro- (Bak, Bax, and Caspase-3) and anti-apoptotic genes (Bcl-2), pyroptosis-related genes (Caspase-1, Caspase-4, Caspase-5, NLRP3, and GSDMD), and pro-inflammatory cytokines genes (interleukins 6 and 1β, and TNF-α) were analyzed via qRT-PCR. The obtained simulation of our result clearly showed that Hesperetin led to the disintegration of the cross-linked structure of organized Aβ1-42 fibrils. Increased RMSD, Rg, and SASA values ​​might lead to destabilization of Aβ1-42 fibrils in the presence of Hesperetin. Our experimental study also demonstrated that Hesperetin increased cell viability in SH-SY5Y cells induced by LPS and Aβ1-42. Hesperetin effectively reverses the enhanced apoptosis caused by LPS and Aβ1-42. Our findings indicated that Hesperetin significantly reduced the elevated expression levels of pro-inflammatory cytokines in the SH-SY5Y cells induced by LPS and Aβ1-42. Treatment with Hesperetin led to a notable downregulation of the enhanced expression of pyroptotic-related genes in LPS and Aβ1-42 induced cells. The details of the molecular level along with the investigation of the physicochemical properties of Hesperetin regarding the mechanism of destabilization of Aβ1-42 fibrils introduce it as a promising therapeutic agent for AD management. Our experimental findings also indicate that Hesperetin is a compound that prevents neuronal death by reducing inflammation and inhibiting apoptosis and pyroptosis.