ABSTRACT
AIM: To investigate whether ?-tyrosol could induce expression of DT-diaphorase (NQO 1) gene and inhibit proliferation of hepatoma cells and their relationship.METHODS: The DT-diaphorase activity, mRNA expression and cell proliferation were examined using direct measurement of DT-diaphorase from cells cultured in microtiter wells, semi-quantitative reverse transcription-PCR (RT-PCR) technique and crystal violet assay after treatment of SMMC-7721 cells with ?-tyrosol for 24 h. RESULTS: Treatment of SMMC-7721 cells with ?-tyrosol caused an increase in DT-diaphorase activity and DT-diaphorase mRNA expression in a dose-dependent manner. A statistically significant correlation between DT-diaphorase mRNA levels and enzyme activities was evident. In almost the same concentration range of 70 mg/L to 100 mg/L, ?-tyrosol resulted in a dose-dependent inhibition of cell proliferation which well inversely correlated with DT-diaphorase activity.CONCLUSION: ?-tyrosol can induce DT-diaphorase activity and enhance expression of its gene, which may contribute to antiproliferation of hepatoma cells caused by the same chemical.