D-limonene pretreatment attenuates acute myocardial infarction injury and modulates PPARα-associated fatty acid oxidation and inflammatory stress.

D-limonene is a natural monoterpene with antioxidant and anti-inflammatory properties, but its effects on metabolism-linked injury after acute myocardial infarction (AMI) remain unclear. We investigated whether oral D-limonene pretreatment attenuates AMI injury through modulation of peroxisome proliferator-activated receptor-α (PPARα)-linked fatty acid oxidation (FAO) and inflammatory stress. Putative targets were prioritized by network pharmacology, molecular docking, and a 100-ns molecular dynamics simulation. Male C57BL/6J mice received D-limonene (50 mg/kg/day, oral gavage) for 14 days before permanent coronary ligation. Cardiac function, survival, histopathology, and metabolic, oxidative, inflammatory, and apoptotic markers were assessed. Hypoxic H9c2 cells were used for dose screening and pathway validation with the PPARα agonist WY-14643 and antagonist GW6471. D-limonene pretreatment improved post-infarction survival and partially preserved cardiac function, reduced ventricular dilation, tissue disorganization, and collagen deposition, increased PPARα, FABP3, CPT1A, and CPT1B signals, and decreased 4-HNE, phosphorylated NF-κB p65, COX-2, BAX, and cleaved caspase-3 signals. WY-14643 reinforced, whereas GW6471 weakened, the metabolic and cytoprotective responses associated with D-limonene. In a human PPARα reporter-cell system, D-limonene increased reporter activity in a concentration-related and GW6471-sensitive manner. These findings support an association between D-limonene-mediated preventive cardioprotection and modulation of PPARα-linked metabolic-inflammatory stress, without establishing direct physical receptor engagement.