Abstract

• Acetaminophen is a mild analgesic and antipyretic agent that is safe and effective when taken in therapeutic doses. Ingestion of overdoses, however, may lead to acute liver failure accompanied by centrilobular degeneration and necrosis. The toxicity of acetaminophen is generally thought to be caused by direct interaction of its reactive metabolites with cellular macromolecules. Cell death, defined as an irreversible loss of vital cellular function and structure, can occur by either necrosis or apoptosis. Until recently, investigation into liver cell death has focused on cell necrosis although it is now appreciated that both apoptosis and necrosis may contribute to liver cell death. The present study examined cultured NCTC-1469 cells for LDH release and DNA laddering and their association with cell death. NCTC-1469 cells were cultured in NCTC-135 medium containing 10% horse serum for 72hr, and changed medium to fresh medium containing acetaminophen(from 0,5mM to 5mM). Cell viability was examined by MTT method and cell necrosis was assessed lactate dehydrogenase leakage. Genomic DNA fragmentation was assessed qualitatively by 1.5% agarose gel electrophoresis. Acetaminophen decreased MTT levels(p<0.05) and increased release of LDH(p<0.05) in dose-dependendent manner. Agarose gel electrophoresis revealed a "ladder" of DNA fragments in all acetaminophen concentration. Cell viability strongly correlated with cell necrosis(r²=0.946). These results show that acetaminophen induced both necrosis and apoptosis in NCTC-1469 cells and cell death mainly attributed to apoptosis.
• Keywords: Acetaminophen; Hepatotoxicity; NCTC-1469 cell; Necrosis; Apoptosis