OBJECTIVETo study the effect of hydroquinone on apoptosis of bone marrow mononuclear cells, and to evaluate the toxic effect of benzene on stem cells.

METHODSCell morphology was observed by HT fluorescent stain method, and DNA fragments were analyzed by agarose gel electrophoresis. Anti-Annexin V FITC plus PI staining for apoptotic and necrotic rate was examined by flow cytometer.

RESULTSAfter adding different concentrations of hydroquinone to the cells for 6 h culture, the fluorescent intensity of nucleus increased, the color of nucleus became deep and inhomogeneous, and the chromatin was condensed and distributed around the neucleus. DNA ladder was detected in all samples. Cell apoptotic rate in different concentration of hydroquinone groups was significantly higher than that in blank control group (P < 0.05). With the increase of the concentration of hydroquinone, the apoptotic and necrotic rate also increased. The optimal concentration of hydroquinone was 50 micro mol/L. When it was >or= 75 micro mol/L, the necrotic rate increased significantly. Hydroquinone-induced apoptosis was associated with culture time at the concentration of 50 micro mol/L, and the peak apoptotic time was 10 h, then the apoptotic rate decreased and necrotic rate increased.

CONCLUSIONHydroquinone can induce apoptosis of bone marrow mononuclear cells in vitro with dose-effect and time-effect relationship.