[Effects of flavone from leaves of Diospyros kaki on expression of apoptosis signal-regulating kinase 1 and rat vascular smooth muscle cells proliferation by tumor necrosis factor alpha in vitro].

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.

CONCLUSIONS

Flavone from leaves of Diospyros kaki can significantly inhibit expression of ASK1 protein stimulated by TNF-alpha of rat VSMcs in vitro.