Effect Of Tert-butylhydroquinone On Cytotoxicity To Rats Bone Marrow Cells Induced By Benzene

As an important chemical material, solvent, dilution and fuel, Benzene has a broad range of use in modern industry and agriculture. It has been reported that chronic exposure to benzene leaded to the reduction of blood cells, bone marrow suppression, even aplastic anemia and leukemia. Although the exact mechanism for the toxicity of benzene is not fully identified, it is believed that the toxicity of benzene is dependent upon its bioactivation, and can be decreased by the detoxifying enzymes activities involved in the metabolism of Benzene. Recently the researches revealed that some natural and synthetic chemicals can lessen the damage to the organism induced by toxic through intervening in the metabolism of various kinds of xenobiotics. Tert-butylhydroquinone (tBHQ) is a synthetic phenolic antioxidant, some studies using animals model demonstrated that tBHQ can protect animals against radiation and the acute toxicity of various xenobiotics and mutagens, presumably through the induction of many phase II detoxifying enzymes. There was no informatiom about the effect of tBHQ on cytotoxicity to bone marrow cells induced by benzene.Our study is to investigate whether tBHQ can also protect rats' bone marrow cells from cytotoxicity induced by benzene in vitro and its possible mechanism. For this purpose rat bone marrow cells were divided into two groups randomly. Cells of control group were stimulated by 0, 5, 10,15 and 20 mmol/L benzene for 2, 4 and 6h respectively. Cells of tBHQ- pretreated group were treated by 100μmol/L tBHQ for 12h followed by the same conditions as the control group. DNA damage was detected by single cell gel electrophoresis assay (SCGE) and cell apoptosis was examined by flow cytometry. We also measured the activities of NAD(P)H:quinone oxidoreductase (NQO1) in rats bone marrow cells before and after tBHQ treatment. The Results of our experiment is that DNA damage and apoptosis of bone marrow cells increased with the growing of benzene concentration and time of treatment in control group.DNA migration and the lengths of DNA migration of rats bone marrow cells under 5, 10, 15 and 20 mmol/L benzene treatment in tBHQ-pretreated group were significant lower than those in control group at the same time point (P<0.05); The apoptosis of rats bone marrow cells stimulated by 15,20 mmol/L benzene for 2h and 10,15,20 mmol/L benzene for 4h as well as 5, 10,15,20 mmol/L benzene for 6h were also significant lower than those in control group (P