ABSTRACT
<p><b>OBJECTIVE</b>To determine the effects and related mechanism of Scutellaria baicalensis stem-leaf total flavonoid (SSTF) on vascular smooth muscle cells (VSMCs) proliferation induced by high triglyceride blood serum (HTG).</p><p><b>METHOD</b>VSMCs isolated from rat aorta were cultured in vitro and proliferation was stimulated by HTG, SSTF was added to influence the proliferation of VSMCs. The proliferation and cell cycle of VSMCs were determined by MTT assay and flow cytometry, respectively. CO released into the culture media was quantitated by measuring carbon monoxide hemoglobin (COHb). The protein expressions of HO-1 and extracellular signal-regulated kinase (ERK/p-ERK) were detected by Western blot analysis.</p><p><b>RESULT</b>500 mg x L(-1) SSTF could obviously suppress the cell multiplication by HTG's induction, remarkably increase the production of COHb in VSMCs, obviously suppresse the mitotic cycle progress of VSMCs (P < 0.05, P < 0.01), in the time and dosage dependence. Furthermore, 500 mg x L(-1) SSTF remarkably declined the ERK/p-ERK protein expression (P < 0.01), but did not have the influence on the HO-1 protein's expression.</p><p><b>CONCLUSION</b>SSTF inhibited the proliferation of VSMCs directly by blocking cell cycle progression, and the ERK signal transduction way possibly participated in the cytoprotection of SSTF.</p>