Combination of Plasma Pharmacochemistry, RNA-Seq, and Molecular Docking Strategies to Reveal the Mechanism of the Alkaloid Fraction of Nelumbinis folium for the Treatment of Hyperlipidemia

<i>Nelumbinis folium</i> (<i>N. folium</i>) exhibits hypolipidemic effects and shows great potential for application in lipid-lowering drugs and healthcare products. This study aimed to investigate the mechanism underlying the hypolipidemic effects of the alkaloid fraction of <i>N. folium</i> (AFN). Animal experiments demonstrated that AFN significantly reduced blood lipid levels and ameliorated liver damage in hyperlipidemic mice. RNA-seq analysis identified 26 reverse-regulated differentially expressed genes (DEGs), which were primarily involved in the PPAR signaling pathway, fat digestion and absorption, and fatty acid degradation. Using UPLC-MSⁿ, 30 plasma-absorbed components were identified, including 13 prototype alkaloids. Among these, three key active components-nuciferine, <i>N</i>-nornuciferine, and <i>N</i>-methylisococlaurine-were screened via network topology analysis. Molecular docking revealed strong binding affinities between these compounds and key targets. The results showed that <i>N</i>-methylisococlaurine bound to <i>SLC27A4</i> and <i>CPT1A</i> with strong affinity, while nuciferine and <i>N</i>-nornuciferine bound to <i>ACADVL</i> and <i>PPARA</i>. RT-qPCR results confirmed that AFN modulates the expression of <i>FABP1</i>, <i>SLC27A4</i>, <i>PPARA</i>, <i>CPT1A</i>, <i>ACAA2</i>, <i>APOC3</i>, and <i>APOA4</i>. These findings suggest that AFN exerts its hypolipidemic effects through multi-component, multi-target, and multi-pathway mechanisms.