Phytosterol-enriched corn and wheat germ blended oil improves lipid metabolism in hyperlipidemia via the AMPK/PPARα/CPT1 pathway

Background While plant sterol-enriched oils are known to improve lipid profiles, the effects and mechanisms of phytosterol-enriched corn and wheat germ blended oil (PCWGO) remain unclear. Objective This study evaluated the lipid-regulating effects of PCWGO in individuals with borderline dyslipidemia and hyperlipidemic rats, and explored the underlying mechanisms. Methods A randomized, single-blind, parallel-controlled trial was conducted in 60 adults assigned to PCWGO or peanut oil (PO) for 3 months. Serum lipids and oxidative stress markers were measured. In parallel, high-fat diet–induced hyperlipidemic rats received PCWGO or PO for 8 weeks, followed by assessment of lipid levels, liver histology, and AMPK/PPARα/CPT1 pathway proteins. Results In the human trial, the PCWGO group showed significant reductions in serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo B), along with increased superoxide dismutase (SOD), glutathione (GSH), and total antioxidant capacity (TAOC), and decreased reactive oxygen species (ROS) ( P < 0.05). In hyperlipidemic rats, PCWGO similarly reduced serum TC, TG, and LDL-C after eight weeks ( P < 0.05). Western blot analysis showed upregulated hepatic expression of phosphorylated AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor α (PPARα), and carnitine palmitoyltransferase 1 (CPT1) in the PCWGO group versus the PO group ( P < 0.05). Conclusions PCWGO effectively improved lipid metabolism in both humans and animal models and may have beneficial effects on oxidative status. Its hypolipidemic effects may be related to activation of the AMPK/PPARα/CPT1 pathway, promoting fatty acid β-oxidation. These findings support phytosterol-enriched blended germ oil as a potential dietary strategy for managing dyslipidemia.