Effects of glycosides components and combinations of Buyang Huanwu decoction on vascular smooth muscle cells proliferation and related signaling pathway

This paper was aimed to explore the effects of glycosides, the effective component of Buyang Huanwu decoction, and its main active components such as astragaloside Ⅳ, amygdalin, peoniflorin and their combinations on vascular smooth muscle cells (VSMC) proliferation, clarify the major active materials of anti-VSMC proliferation and investigate the mechanisms via the signal transduction pathway. Plasma containing drug was prepared via oral administration in rats. VSMCs of rats aorta were cultured, and then VSMC proliferation was stimulated by using platelet derived growth factor (PDGF).The plasma containing drug was added to detect the activity of cell proliferation, cell cycle and related protein expressions of signaling pathway such as extracellular signal-regulated kinase (ERK), phos-phatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and Janus kinase/signal transducer and activator of transcription (JAK/STAT). After being stimulated by PDGF, the proliferation activity of VSMC was strengthened (P<0.01), G₀/G₁ phase cells were decreased (P<0.01), S/M phase cells were increased (P<0.01), and PcNA, cyclin D1 protein expressions related to cell cycle were up-regulated (P<0.01). Glycosides, astragaloside Ⅳ, amygdalin, peoniflorin and their combinations could inhibit the cell proliferation (P<0.05 or P<0.01) in a dose-effect relationship and time-effect relationship. They could increase G₀/G₁ phase cells (P<0.01), decrease S/M phase cells (P<0.01), and down-regulate the protein expressions of PCNA, cyclin D1 (P<0.01); and the effects of the combinations were greater than those of single active component (P<0.05). After VSMC proliferation was induced by PDGF, p-ERK1/2 expression was increased (P<0.01), PI3K expression was down-regulated while p-PI3K expression was up-regulated (all P<0.01), and STAT3expression was reduced while p-STAT3 expression was increased (all P<0.01). Glycosides, astragaloside Ⅳ, amygdalin, peoniflorin and the combinations of these active components could reduce p-ERK1/2 expression (P<0.05), increase PI3K expression (P<0.01), decreasep-PI3K expression (P<0.05 or P<0.01), increase STAT3 expression (P<0.01), and decrease p-STAT3 expression (P<0.05 or P<0.01). These results suggested that PDGF could induce the cell cycle conversion of VSMC, leading to VSMC proliferation. The mechanism was related to the activation of ERK, PI3K/Akt and JAK/STAT signaling pathways. Glycosides and its main active components such as astragaloside Ⅳ, amygdalin, peoniflorin and their combinations can inhibit the cell cycle conversion of VSMC, with the effect against VSMC proliferation, and the mechanisms may be associated with the inhibition of PI3K/Akt, mitogen-activated protein kinase (MAPK) and JAK/STAT signaling pathways. astragaloside Ⅳ, amygdalin and peoniflorin were the major active materials of anti-VSMC proliferation, and their combination showed enhanced effect.