β ‐Sitosterol from Camellia oil integrated photothermal liposomes increasing redox‐balanced anti‐inflammation in macrophages

BACKGROUND: Camellia oleifera Abel. oil (Camellia oil) is a premium edible woody oil traditionally utilized in East Asia for treating burns and inflammatory disorders; however, the poor bioavailability of its active phytosterols severely limits their modern application in functional foods. To overcome this limitation, this study aimed to engineer a photothermally responsive nanoplatform to enhance the bioavailability and enable the controlled release of these dietary bioactives, based on the bioactive profile of Camellia oil. RESULTS: Network pharmacology and molecular docking initially identified β-sitosterol as a core active component of Camellia oil. Subsequently, a photothermally responsive liposomal system was engineered by co-loading β-sitosterol and theabrownin-derived carbon quantum dots. The liposomes exhibited a high photothermal conversion efficiency of 46.6%, enabling controlled, temperature-dependent cargo release. In vitro assays demonstrated potent radical-scavenging capabilities (89.4% against superoxide, 82.8% for ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and 58.6% for DPPH (2,2-diphenyl-1-picrylhydrazyl)). In lipopolysaccharide-stimulated RAW264.7 macrophages, the system significantly reduced intracellular reactive oxygen species levels and downregulated pro-inflammatory genes (iNOS, TNF-α, IL-1β, and IL-6), inhibiting iNOS mRNA expression by 71.6%. Furthermore, upregulation of the reparative gene CD206 indicated a functional shift toward inflammatory resolution. Transcriptomic benchmarking revealed that the system reversed inflammatory homeostasis impairment by modulating the antagonism between inflammatory and metabolic modules, a process bioinformatically predicted to be driven by the regulatory node Pparg. CONCLUSION: This work integrates natural Camellia-derived bioactive components with nanotechnology to coordinate redox status and immune homeostasis, offering a novel strategy for the high-value utilization of woody oil crops as functional ingredients. © 2026 Society of Chemical Industry.