Integrated Lipidomics and Network Pharmacology Reveal the AMPK-Mediated Therapeutic Mechanism of 3,3′-Diindolylmethane in Hepatic Lipid Metabolism

Dysregulation of hepatic lipid metabolism constitutes a central mechanism in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD). 3,3′-Diindolylmethane (DIM), a bioactive compound abundant in dietary Brassica vegetables, exhibited protective effects on hepatocellular carcinoma and metabolic/inflammatory pathologies. Nevertheless, the effects of DIM on hepatic lipid metabolism and its underlying mechanisms remain unclear. Administration of DIM (50 mg/kg bw/day) prevented oxidative stress and hepatic lipid deposition in both high-fat diet (HFD)-fed wild-type (WT) and ob/ob mice. Lipidomics revealed that DIM diminished the lipogenesis and reshaped the hepatic lipid profile. Network pharmacology analysis identified the AMPK signaling pathway as the underlying mechanistic target for DIM in treating MASLD. In both HepG2 cells and mouse primary hepatocytes (MPH), DIM attenuated palmitic acid (PA)-induced cellular lipid accumulation, ROS generation, and reduction in oxygen consumption rate (OCR). These protective effects of DIM were diminished by co-treatment with Compound C (CC), a specific AMPK inhibitor. DIM administration enhanced AMPKα phosphorylation in vivo (WT/ob/ob mice) and in vitro (HepG2/MPH), concomitant with PPARα upregulation and SREBP1/ACC1 downregulation. CC abolished all DIM-induced molecular changes in vitro. Collectively, DIM alleviates hepatic lipid accumulation and oxidative stress in MASLD models through AMPK activation, subsequently modulating PPARα and SREBP1/ACC1 pathways.