Abstract: OBJECTIVE: To ascertain if total flavonoids of Guangzao(Fructus Choerospondiatis)(TFFC) extracted from Guangzao(Fructus Choerospondiatis) can inhibit angiotensin Ⅱ-induced proliferation of cardiac fibroblasts(CFs).METHODS: CFs were cultured by the differential attachment method. A model of cell proliferation was established by stimulation with Ang Ⅱ. Cardiac fibroblasts growth was determined using a hemocytometer. Cell proliferation was detected by methyl thiazole tetrazolium. Lactate dehydrogenase activitywas measured by chemical colorimetric method.RESULTS: Proliferation of TFFC-treated(25, 50,100 mg/L) fibroblasts was significantly less than that of cells in the angiotensin Ⅱ group(P < 0.01),and TFFC inhibited proliferation in a dose-dependent manner. These inhibitory effects were partly blocked by pretreatment with NG-nitro-L-arginine methyl ester(L-NAME) and 1H-[1,2,4]-oxadiazole-[4,3-a]-quinoxalin-1-one(ODQ).CONCLUSION: TFFC inhibited angiotensinⅡ-induced proliferation of cardiac fibroblasts via a mechanism that probably involves activation of the NO-cyclic guanosine monophosphate signaling pathway.

Key words: Flavones, Guangzao(Fructus Choerospondiatis), Angiotensin Ⅱ, Fibroblasts, Nitric oxide, Cyclic GMP