Nuciferine Exerts Anti-Inflammatory Effects in Mice With Non-Alcoholic Steatohepatitis by Regulating the miR-23a-3p-SIRT1-NF-κB Pathway and Akkermansia muciniphila-Extracellular Vesicles.

Abstract

Nuciferine, a lotus leaf extract with low bioavailability, shows beneficial effects on hepatic metabolism and gut microbiota, but its anti-inflammatory mechanisms in non-alcoholic steatohepatitis (NASH) are unclear. This study aimed to clarify how nuciferine mitigates hepatic inflammation in NASH by exploring its interactions with immune pathways and gut microbiota. Initially, a NASH mouse model was induced using a methionine- and choline-deficient diet, with nuciferine administered orally. Furthermore, liver damage was assessed, and hepatic M1 (CD11B⁺ pro-inflammatory) and M2 (CD163⁺ anti-inflammatory) macrophages were quantified. Molecular assays measured SIRT1 gene expression, while miRNA sequencing and dual-luciferase assays explored its role in the SIRT1/NF-κB pathway. Additionally, gut microbiota were analyzed via 16S rRNA sequencing, and fluorescently labeled Akkermansia muciniphila-derived extracellular vesicles (Akk-EVs) were tracked in vivo and in vitro. Treatment with nuciferine reduced liver injury, decreasing pro-inflammatory M1 macrophages and increasing anti-inflammatory M2 macrophages. Meanwhile, it upregulated hepatic SIRT1, suppressing miR-23a-3p to inhibit the NF-κB pathway and promote M1-to-M2 polarization. Gut microbiota analysis showed nuciferine enriched Akkermansia muciniphila, and fluorescent imaging confirmed Akk-EVs entered liver tissues and macrophages, exerting direct anti-inflammatory effects. In conclusion, nuciferine protects against NASH through dual mechanisms: modulating the SIRT1/NF-κB pathway to reduce hepatic inflammation and enhancing Akk-EVs. These findings highlight its therapeutic potential for NASH, linking host immune responses with gut microbiota interactions.