Effect of Korean Magnolia obovata Extract on Platelet-Derived Growth Factor-Induced Vascular Smooth Muscle Cells

Objective:To investigate the effects of Korean Magnolia obovata crude extract(KME)on plateletderived growth factor(PDGF)-BB-induced proliferation and migration of vascular smooth muscle cells(VSMCs).Methods:KME composition was analyzed by high-performance liquid chromatography(HPLC).VSMCs were isolated from the aorta of a Sprague-Dawley rat,incubated in serum free-Dulbecco's modified Eagle's medium in the presence or absence of KME(10,30,100,and 300(xg/mL),then further treated with PDGF-BB(10 ng/mL).VSMC proliferation was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and VSMC migration was determined using the Boyden chamber and scratch wound healing assays.Western blot analysis was used to detect phosphorylation of extracellular signal-regulated protein kinases 1 and 2(p-ERK1/2),protein kinase B(p-Akt),and stress-activated protein kinase/c-Jun NH2-terminal kinase(p-SAPK/JNK).The antimigration and proliferation effects of KME were tested using aortic sprout outgrowth.Results:The HPLC analysis identified honokiol(0.45 mg/g)and magnolol(0.34 mg/g)as the major components of KME.KME(30,100,and 300μg/m L)significantly decreased the proliferation and migration of PDGF-BB-stimulated(10 ng/mL)VSMCs and the PDGF-BB-induced phosphorylation of EKR1/2,Akt,and SAPK/JNK(P<0.05).Furthermore,PDGF-BBinduced VSMCs treated with 300μg/m L of KME showed reduction in aortic sprout outgrowth.Conclusion:KME could inhibit abnormal proliferation and migration of VSMCs by down-regulating the phosphorylation of EKR1/2 and Akt.Thus,KME might be a functional food for preventing vascular disorders.