The objectives of present study were to investigate the effects of benzo[a]pyrene(BaP) on cytotoxicity, lipid peroxidation and antioxidant enzymes in rat hepatocyte primary culture. Primary cultures of rat hepatocytes were incubated for 24 hr, 48 hr or 72 hr in the presence of various concentrations (0, 10, 20, 30, 50 or 100 μM) of BaP. Cytotoxicity and cell viability were determined by measuring glutamic oxaloacetic transaminase(GOT) activity, lactate dehydrogenase(LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) value. Lipid peroxidation was evaluated using thiobarbituric acid reactive substances(TBARS) assay. Effects on antioxidant system were determined by measuring glutathione peroxidase(GPx) activity, glutathione reductase(GR) activity and glutathione concentration. Activities of GOT and LDH, MTT value as well as TBARS concentration were not affected by up to 100 μM of BaP for 24 hr incubation. However, BaP at the concentration of 50 μM for 48 hr incubation or at the concentration of 30 μM for 72 hr incubation began to increase LDH activity and TBARS concentration but decrease MTT value, representing that BaP caused cytotoxicity and decreased cell viability in dose- and time-dependent manners. GPx activity began to be decreased by BaP at the concentration of 50 μM for 72 hr incubation. Whereas, GR activity began to be decreased by BaP at the concentration of 20 μM for 72 hr incubation. Glutathione concentration began to be decreased by BaP at the concentration of 20 μM for 72 hr incubation and was further reduced to 90% by 100 μM of BaP. These results demonstrate that BaP caused cytoctoxicity and decreased cell viability by increasing lipid peroxidation and decreasing glutathione concentration as well as activities of GPx and GR.

• 임태진(상지대학교 생명자원과학대학 생명공학과) | Tae-Jin Rhim Corresponding Author