title: Investigation of rifampicin-induced hepatotoxicity in rat hepatocytes maintained in gel entrapment culture.
abstract: Rifampicin-induced hepatotoxicity has been well recognized in animals and patients. However, it is undetectable in cultured hepatocyte monolayers in vitro at the equivalent toxic concentration in vivo. This study investigated the rifampicin-induced toxicity on rat hepatocytes in gel entrapment vs. in monolayer culture. Thiazolyl tetrazolium reduction and albumin secretion were routinely detected to identify the toxic responses of rat hepatocytes to rifampicin, while reactive oxygen species (ROS) accumulation and intracellular glutathione (GSH) content were assayed as biomarkers of oxidative stress. In addition, Nile red staining and malondialdehyde (MDA) generation were, respectively, used as endpoints for lipid accumulation and peroxidation. After treatment of hepatocytes for 96 h at a serum rifampicin concentration (12 microM), gel-entrapped rat hepatocytes showed significant cellular damage indicated by alternations of all parameters indicated above, while hepatocyte monolayers did not show severe responses. In contrast to a lack of protections by cytochrome P 450 inhibitors, the ROS scavenger (glycyrrhizic acid) and thiol compounds (N-acetylcysteine and GSH) significantly reduced rifampicin toxicity in gel-entrapped hepatocytes. It appears that gel-entrapped rat hepatocytes reflected significant hepatotoxicity of rifampicin in vivo, and this toxicity was most possibly associated with oxidative stress and lipid accumulation.
authors.affiliation: College of Materials Science and Chemical Engineering, Zhejiang University, Zhejiang, People's Republic of China.
authors.forename: Chong
authors.initials: C
authors.lastname: Shen
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Cheng
authors.forename: Donghui
authors.initials: D
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Meng
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000418:Albumins / Q000378:metabolism; D000818:Animals; D000995:Antitubercular Agents / Q000037:antagonists & inhibitors / Q000633:toxicity*; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control; D065607:Cytochrome P-450 Enzyme Inhibitors; D004336:Drug Antagonism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D019695:Glycyrrhizic Acid / Q000494:pharmacology; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D012293:Rifampin / Q000037:antagonists & inhibitors / Q000633:toxicity*; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
chemical_list: D000418:Albumins; D000995:Antitubercular Agents; D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D008315:Malondialdehyde; D019695:Glycyrrhizic Acid; C022616:thiazolyl blue; D005978:Glutathione; D012293:Rifampin; D000111:Acetylcysteine