Hyperoside inhibits the effects induced by oxidized low-density lipoprotein in vascular smooth muscle cells via oxLDL-LOX-1-ERK pathway

Hyperoside is a major active constituent in many medicinal plants traditionally used in Chinese medicines for their anti-inflammatory, antioxidative, and vascular protective effects. Recent studies have focused on the protective effects of hyperoside on hyperlipidemia. However, the molecular mechanisms underlying these effects are unknown. In this study, vascular smooth muscle cells (VSMCs) were treated in vitro with oxidized low-density lipoprotein (oxLDL) in the presence or absence of hyperoside. Western blotting, quantitative PCR, and tetrazolium assay were used to detect lectin-like oxLDL receptor-1 (LOX-1) expression and extracellular signal-regulated kinases (ERK) activation, and to determine VSMCs viability. The results demonstrated that oxLDL promoted LOX-1 expression, ERK activation, and proliferation in VSMCs. Hyperoside significantly inhibited the oxLDL-stimulated effects after long time exposure. However, it promoted ERK activation directly following a short incubation duration (25 min). In conclusion, hyperoside inhibits oxLDL-induced LOX-1 expression, ERK activation, and cell proliferation through the oxLDL-LOX-1-ERK pathway in VSMCs. Our findings suggest a novel role of hyperoside in treating and preventing atherosclerosis.