ABSTRACT
OBJECTIVE: To observe the effects of flavone from leaves of Diospyros kaki on expression of apoptosis signal-regulating kinase 1 (ASK1) and rat vascular smooth muscle cells (VSMCs) proliferation by tumor necrosis factor alpha in vitro. METHODS: Rat aortic VSMCs were cultured in vitro and treated with tumor necrosis factor alpha (TNF-alpha) and flavone from leaves of Diospyros kaki, respectively, and were observed in comparison with the control group. The ratio of cell proliferation was determined by non-radioactive MTS/PES as-say. The expression of ASK1 protein was evaluated by the immunoblotting technique using anti-ASKL antibody. RESULTS: The ratio of cell proliferation was 0.817 +/- 0.074 in the control group, and was 1.865 +/- 0.093 in TNF-alpha20 ng/ml group. It was shown that TNF-alpha significantly induced rat VSMCs proliferation (P < 0.05). The ratio of cell proliferatioh was 0.905 +/- 0.044 in flavone from leaves of Diospyros kaki group corresponding to concentration of 50 microg/ml. It was shown that flavone from leaves of Diospyros kaki alone had no effect on rat VSMCs proliferation (p > 0.05). With TNF-alpha stimulation, flavone from leaves of Diospyros kaki significantly inhibited rat expression of ASK1 protein enhanced by TNF-alpha was significantly inhibited rat-VSMNCs proliferation (1.247 +/- 0.061 vs. 1.865 +/- 0.093, p < 0.05). The expression of ASK1 protein enhanced by TNF-alpha was significantly inhibited by flavone from leaves of Diospyros kaki in VSMCs. CONCLUSION: Flavone from leaves of Diospyros kaki can significantly inhibit expression of ASK1 protein stimulated by TNF-alpha of rat VSMcs in vitro.
