Zhujing Pill ameliorates age-related macular degeneration by regulating lipid metabolism, complement activation, and inflammatory responses: an integrated network pharmacology and metabolomics study.

ETHNOPHARMACOLOGICAL RELEVANCE: Age-related macular degeneration (AMD) is a leading cause of irreversible visual impairment in the elderly, with particularly limited therapeutic options for dry AMD. Zhujing Pill (ZJP), a traditional Chinese medicinal formula recorded in Taiping Sheng Hui Fang of the Northern Song Dynasty, has historically been prescribed for visual disorders attributed to age-related "liver and kidney deficiency", a traditional syndrome sharing core clinical features with AMD. However, the pharmacological basis and molecular mechanisms underlying its therapeutic effects remain largely unexplored.

AIM OF THE STUDY: To systematically elucidate the bioactive constituents and therapeutic mechanisms of ZJP in AMD using an integrated strategy combining network pharmacology, molecular docking, metabolomics, and experimental validation.

MATERIALS AND METHODS: The chemical profiles and principal constituents of ZJP and ZJP-medicated serum (ZJW) were characterized by UHPLC-MS analysis. Network pharmacology and molecular docking were applied to identify key compounds and potential molecular targets. Protective effects were evaluated using lysophosphatidylcholine (LPC)-induced ARPE-19 cell injury and sodium iodate-induced AMD mouse models. Retinal structure and function were assessed by behavioral testing, optical coherence tomography (OCT), and histopathology. Serum and intracellular metabolomics were performed using UPLC-QTOF-MS. The expression of inflammatory, complement-related, and lipid and cholesterol metabolism-associated genes were analyzed by RT-qPCR.

RESULTS: A total of 386 constituents were identified in ZJP, and 222 compounds were detected in ZJP-medicated serum, predominantly flavonoids, iridoids, phenylethanoid glycosides, and bile acid-related metabolites. Network pharmacology highlighted quercetin, kaempferol, isorhamnetin, and sophoranol as key active compounds targeting core proteins such as AKT3, HSP90AA1, and PIK3CA. In vivo evaluations, compared with the AMD model group, high-dose ZJP treatment increased the time spent in the dark chamber by 90.51% (P < 0.001), significantly restored retinal thickness by 84.76% (P < 0.001), and improved the histopathological score by 52.88% (P < 0.001). In ARPE-19 cells, ZJP increased LPC-induced cell viability by 105.56% (P < 0.001), inhibited complement overactivation, and suppressed inflammatory cytokine. Metabolomic analyses demonstrated that ZJP markedly corrected lipid metabolism, bile acid biosynthesis, energy metabolism, and inflammatory eicosanoid pathways, and promote retinal cholesterol efflux via upregulation of LXRα and ABCA1, and modulate LDLR-mediated cholesterol uptake.

CONCLUSIONS: Rooted in the TCM theory of 'nourishing liver and kidney to benefit eyesight', ZJP (composed of Cuscutae Semen, Plantaginis Semen, and Rehmanniae Radix) ameliorates AMD by regulating LXRα/ABCA1-mediated cholesterol efflux, suppressing complement activation, and normalizing lipid and bile acid metabolism. These findings provide mechanistic support for the traditional use of ZJP in ocular disorders and highlight its potential as a therapeutic candidate for AMD.