Curcumin attenuates DEHP-induced splenic immunotoxicity in chicks: involvement of Mfn2-mtROS-associated mitochondrial homeostasis.

Bis(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental contaminant frequently detected in environmental and food-related matrices and associated with immune dysregulation and inflammatory injury. However, the mechanistic basis of DEHP-induced splenic immunotoxicity and its potential intervention strategies remain incompletely understood. Here, we combined an in vivo chick model and in vitro cell systems to investigate whether curcumin mitigates DEHP-induced splenic injury by modulating mitochondrial homeostasis. DEHP exposure markedly impaired growth performance, increased the spleen index, induced histopathological and ultrastructural damage, and elevated inflammatory cytokine production. These alterations were accompanied by mitochondrial dysfunction, excessive mtROS accumulation, dysregulated Mfn2/Drp1 signaling, macrophage M1 polarization, and concurrent changes in apoptosis-, pyroptosis-, and necroptosis-associated signaling. Integrated network pharmacology, molecular docking, molecular dynamics simulation, protein-stability assays, and pharmacological intervention supported Mfn2 as a candidate molecule associated with the protective effects of curcumin. Curcumin reduced mtROS accumulation, improved mitochondrial membrane potential and ATP production, limited cytoplasmic mtDNA release, and suppressed macrophage M1 polarization and multiple programmed cell death-related signaling. Collectively, the findings suggest that mitochondrial dysfunction contributes to DEHP-induced splenic immunotoxicity and that modulation of Mfn2-mtROS-associated mitochondrial homeostasis may participate in the protective effects of curcumin. This mechanistic hazard study provides evidence from an avian model but does not directly represent typical environmental exposure or establish human-health effects.