Freeze-Dried Poecilobdella manillensis Powder Regulates Cholesterol Homeostasis to Alleviate Hyperlipidemia

Hyperlipidemia (HL) is a major metabolic disorder and a critical risk factor for cardiovascular diseases, closely associated with oxidative stress, inflammation, and disrupted cholesterol homeostasis. Freeze-dried Poecilobdella manillensis powder (FDPMP), a traditional medicinal product, has shown therapeutic potential against hyperlipidemia; however, its underlying mechanisms remain largely unclear. In this study, HL was induced in ApoE−/− mice by feeding a high-fat diet (HFD) for eight weeks, during which FDPMP or simvastatin (positive control) was orally administered daily. Concurrently, an in vitro foam cell model was established by exposing RAW264.7 macrophages to oxidized low-density lipoprotein (ox-LDL, 80 μg/mL) for 24 h, with FDPMP pretreatment applied 30 min prior to ox-LDL stimulation. Following intervention, serum lipid profiles, hepatic oxidative stress markers, histopathological changes, and cholesterol metabolism-related gene and protein expression were systematically evaluated. FDPMP administration significantly improved serum lipid profiles by reducing triglycerides, total cholesterol, and low-density lipoprotein cholesterol, while increasing high-density lipoprotein cholesterol levels. Additionally, FDPMP alleviated histopathological damage in the liver, kidney, and heart, enhanced antioxidant enzyme activities, and attenuated oxidative stress. Untargeted metabolomic analysis revealed that FDPMP markedly modulated key metabolic pathways, including choline metabolism, glycerophospholipid metabolism, and arachidonic acid metabolism. Mechanistically, FDPMP restored cholesterol homeostasis through dual regulation of cholesterol metabolism, characterized by upregulation of cholesterol 7α-hydroxylase (CYP7A1) to promote bile acid-mediated cholesterol excretion, alongside downregulation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and synthase (HMGCS1) to inhibit cholesterol biosynthesis. In vitro, FDPMP effectively suppressed ox-LDL-induced foam cell formation, reduced intracellular lipid accumulation, and mitigated oxidative stress in macrophages. Collectively, these findings demonstrate that FDPMP ameliorates hyperlipidemia through coordinated regulation of cholesterol synthesis and excretion, coupled with systemic metabolic reprogramming and antioxidative effects. This study provides mechanistic insights supporting FDPMP as a promising natural therapeutic candidate for hyperlipidemia and related metabolic disorders.