Syzygium caryophyllatum derived silver nanoparticles enhance GLUT4 expression via AMPK-associated signaling in adipocytes

Adipocyte insulin responsiveness depends on AMPK signaling and GLUT4 trafficking, yet biogenic silver nanoparticle (AgNP) effects remain underexplored. This study extends prior synthesis/characterization of Syzygium caryophyllatum-mediated SC-AgNPs (21.78 nm TEM, λmax 421 nm) to 3T3-L1 adipocyte signaling. The identical batch, verified stable by UV-Vis and visual inspection, was tested across viability (MTT), ROS (DCFDA), mitochondrial function (TMRE), apoptosis (Annexin V/PI), and AMPK/GLUT4 regulation (endpoint RT-PCR, Western blot) using vehicle controls. SC-AgNPs showed excellent biocompatibility (IC50 605.8 μg/mL, >95% viability at 5-50 μg/mL) with hormetic bioactivity: controlled ROS elevation (1.3-fold), mitochondrial hyperpolarization (2.21-fold), versus apoptosis at IC50 (91.7%). At sub-toxic working concentrations, GLUT4 mRNA/protein increased 1.55/1.6-fold (GAPDH/β-actin normalized) despite AMPK reduction (0.2-0.7-fold), suggesting post-translational AMPK-associated signaling. These findings demonstrate SC-AgNPs predict insulin-independent GLUT4-mediated glucose handling via redox modulation, establishing nanoparticle-specific metabolic effects for future functional validation (p-AMPK, GLUT4 translocation, glucose uptake assays).