CASP9 and cancer: The formulated allicin-loaded SLNs measured 67.01 nm in size with a surface charge of −29.29 mV. SLNs significantly reduced the viability of A549 cancer cells after 48 h, while normal HFF cells remained unaffected. Flow cytometry analysis indicated an increase in the subG1 peak and a notable upregulation of caspase-3 and caspase-9, with minimal impact on caspase-8, highlighting an intrinsic apoptotic pathway. Additionally, the SLNs exhibited strong antioxidant activity, effectively inhibiting ABTS and DPPH free radicals.