Objective： To investigate and compare the effects and mechanisms of three functional parts of Dahuang Zhechong Pill （大黄〈庶虫〉虫丸, DHZCP）, including drugs with the function of removing blood stasis and promoting blood circulation （FP- I ）, drugs with the function of expelling heat and moistening dryness （FP-II）, and drugs with the function of nourishing yin and replenishing blood （FP-m） of DHZCP, on platelet-derived growth factor （PDGF）-stimulated vascular smooth muscle cells （VSMCs） proliferation with the method of serum pharmacology. Methods： VSMCs proliferation of rat was assayed by measuring the cell viability with the 3-（4, 5-dimethylthiazol-2yl）-2, 5-diphenyltetrazolium bromide （Ml-I＇） method. DNA synthesis in VSMCs was examined by detecting 5＇-bromo-2＇-deoxyuridine incorporation with the immunocytochemical method. Cycle of VSMCs was evaluated with flow cytometry. Expression of cyclin D1, p27, PKC a, and phosphorylated extracollular signal regulated kinase 1/2 （ERK1/2） was quantified by the Western blotting method. Results： The FP- I and FP-m containing serum was capable of inhibiting PDGF-stimulated proliferation and DNA synthesis of VSMCs, arrested VSMCs in G1 phase, downregulated cycUn D1, and upregulated p27 expression （P〈0.01 or P〈0.05）. The FP- I and FP-11I containing serum also inhibited the PDGF-induced phosphorylation of tyrosine of ERK1/2 and PKCo~ expression （P〈0.01 or P〈0.05）. Conclusions： FP- I and FP-$ of DHZCP are able to inhibit VSMCs proliferation via interrupting PKC a-ERK1/2 signaling, modulating the expression of cell cycle proteins to result in arresting the cells in G1 phase. The inhibitory effect is mainly related to the function of removing blood stasis and promoting blood circulation, slightly to the function of nourishing yin and replenishing blood, but not to the function of expelling heat and moistening dryness.
Objective： To investigate effects of Dahuang Zhechong Pill （大黄庶虫丸, DHZCP） on the cell cycle and the related signal pathways in vascular smooth muscle cells （VSMCs） stimulated by platelet-derived growth factor （PDGF） with the method of serum pharmacology. Methods： DNA synthesis in VSMCs was examined by detecting 5＇-bromo-2＇-deoxyuridine incorporation with the immunocytochemical method. The cycle of VSMCs was evaluated with flow cytometry. Expressions of cyclin D1, p27, protein kinase C α （PKC α）, and phosphorylated extracellular signal regulated kinase 1/2 （ERK1/2） were quantified by Western blot method. Results： DHZCP containing serum significantly inhibited DNA synthesis of PDGF-stimulated VSMCs, arrested the cells in G1 phase, modulated the protein expressions of cyclin D1 and p27, and suppressed the activation of PKC α and ERK1/2. Conclusion： DHZCP containing serum inhibits VSMCs proliferation via modulating the expressions of cell cycle proteins to arrest the cell in G1 phase, which is attributed to, at least in part, suppressing PKC α -ERK1/2 signaling in VSMCs.
