DHDK, a Plant-Derived Natural Small Molecule, Protects Against Doxorubicin-Induced Cardiotoxicity via the PPARG-CPT1B-FAO Axis.

Background: Doxorubicin (DOX) is a highly effective chemotherapy drug, but its use is limited by dose-dependent cardiotoxicity, driving the search for protective natural products. Although the herb Viscum coloratum (Kom.) Nakai is known for its cardiovascular benefits, the cardioprotective effects and mechanisms of its isolated compound, DHDK, remain unexplored. Methods: The protective effect of DHDK was first evaluated in DOX-injured H9c2 cardiomyocytes. Subsequently, an integrated network toxicology (incorporating DOX-induced toxicity targets and relevant chronic disease pathways such as aging and lipid metabolism) and pharmacology (DHDK) approach identified core targets, which were then refined through Protein-Protein Interaction (PPI) analysis and molecular docking. The underlying mechanism was investigated using lipidomics and validated through a series of in vitro assays, including CCK-8, q-PCR, biochemical tests, and flow cytometry, as well as in an in vivo rat model. Results: DHDK significantly alleviated DOX-induced cardiomyocyte toxicity. Integrated analysis identified 56 intersecting targets, with PPARG confirmed as the primary target via PPI and molecular docking. Lipidomics revealed that DHDK potently attenuated DOX-induced accumulation of pathogenic lipids (e.g., fatty acids, ceramides). Mechanistically, DHDK activated PPARG, which in turn upregulated CPT1B, a key regulator of fatty acid β-oxidation (FAO). This enhanced cell viability, ATP production, and mitochondrial membrane potential while reducing oxidative stress. These protective effects, which were abolished by the inhibition of PPARG or CPT1B, were further validated in vivo. Conclusion: This study demonstrates that DHDK exerts its cardioprotective effect by activating the PPARG-CPT1B-FAO axis, effectively correcting lipid metabolic disorders. Given that lipid dysregulation is a hallmark of various internal metabolic diseases, DHDK may also hold therapeutic potential for other heart conditions driven by metabolic disturbances, such as diabetic cardiomyopathy, highlighting its broad relevance to the field of internal diseases.