Enhancement effect of polychlorinated biphenyl on benzo (a) pyrene-induced DNA damage in HepG2 cells / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effect of polychlorinated biphenyl, Aroclor1254 on benzo (a) pyrene [B (a) P]-induced DNA damage in HepG2 cells.</p><p><b>METHODS</b>HepG2 cells were pretreated with Aroclor1254 (11.5, 23 and 46 micromol/L) for 24 hours and then exposed to B (a) P (50 micromol/L). DMSO (10 ml/L) was used as solvent control. Single cell gel electrophoresis (SCGE) and high-performance liquid chromatography-electrochemical detection (HPLC-EC) assays were applied to detect DNA single-strand breaks and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in HepG2 cells, respectively.</p><p><b>RESULTS</b>Average Oliver tail moment (OTM) and 8-OHdG level in HepG2 cells were significantly increased in B (a) P treated group (1.66 +/- 0.21), (23.31 +/- 6.02) 8-OHdG/10(6)dG than that in solvent control (0.79 +/- 0.15), (12.31 +/- 3.24) 8-OHdG/10(6)dG, respectively. In Aroclor 1254 treated group (11.5, 23.0, 46.0 micromol/L), average OTM were 0.88 +/- 0.20, 1.01 +/- 0.15 and 1.10 +/- 0.16, and 8-OHdG levels were (19.57 +/- 7.57), (22.80 +/- 9.16) and (31.74 +/- 9.25) 8-OHdG/10(6)dG, respectively. A concentration of 46 micromol/L Aroclor1254 caused a significant increase of 8-OHdG level as compared with the solvent control. After pretreatment of HepG2 cells with Aroclor1254 (11.5, 23.0 and 46.0 micromol/L), B (a) P induced more DNA strand breaks (OTM: 2.14 +/- 0.22, 2.43 +/- 0.32 and 2.71 +/- 0.31) and 8-OHdG [(32.50 +/- 3.81), (49.23 +/- 16.66) and (60.36 +/- 18.04) 8-OHdG/10(6)dG] in HepG2 cells than B (a) P alone.</p><p><b>CONCLUSION</b>Aroclor1254 might enhance B (a) P-induced DNA damage in HepG2 cells, which should imply a synergistic effect of Aroclor1254 on the genotoxicity of B (a) P.</p>

Analysis of serum glutathione S-transferase and urinary 8-hydroxy-2-deoxyguanosine in coke oven workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the application of serum glutathione S-transferase (GST) and urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) as the monitoring biomarkers for coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs).</p><p><b>METHODS</b>47 male coke oven workers and 31 male control workers were investigated. Urinary 8-OHdG and serum GST were analyzed using high performance liquid chromatography (HPLC) with electrochemical detection and test kit. Urinary 1-hydroxypyrene (1-OHP) as internal exposure of PAHs was also determined simultaneously by alkaline hydrolysis and HPLC.</p><p><b>RESULTS</b>The values of urinary 1-OHP, serum GST and urinary 8-OHdG were reported as median with interquartile range (P(25)-P(75)). Urinary 1-OHP [5.7 (1.4-12.0) micromol/mol Cr], serum GST [22.1 (14.9-31.2) U/ml], and urinary 8-OHdG [1.9 (1.4-15.4) micromol/mol Cr] in coke oven workers were significantly higher than in control workers [3.0 (0.5-6.4) micromol/mol Cr (P < 0.05), 13.1 (9.5-16.7) U/ml (P < 0.01), and 1.3 (1.0-4.0) micromol/mol Cr (P < 0.05) respectively]. Categorizing by smoking status, significant differences in urinary 1-OHP and serum GST were found only in smokers among coke oven workers compared to control workers (P < 0.01), and 8-OHdG levels only in non-smokers (P < 0.01). Additionally, there was significant correlation between urinary 1-OHP and serum GST activity (r(s) = 0.31, P < 0.01, n = 78). The multiple logistic regression analysis showed that coke oven workers were at the higher risk of having GST activities above 16.7 U/ml (OR = 13.2) and 8-OHdG levels above 1.8 micromol/mol creatinine (OR = 4.4). High body mass index was an independent factor to affect urinary 8-OHdG levels.</p><p><b>CONCLUSIONS</b>The elevated serum GST activities and increased oxidative DNA damage were found in the coke oven workers. Occupational exposure and smoking interact on each other. Serum GST may be used as a biomarker for assessing the exposure of PAHs. Assay of urinary 8-OHdG may be useful for evaluating the risk of lung cancer in coke oven workers.</p>