title: Critical roles of cellular glutathione homeostasis and jnk activation in andrographolide-mediated apoptotic cell death in human hepatoma cells.
abstract: Andrographolide (ANDRO), isolated from the traditional herbal medicine Andrographis paniculata, is reported to have the potential therapeutic effects for hepatocellular carcinoma (HCC) in our previous reports. Here, we investigated the mechanism of ANDRO-mediated apoptotic cell death, focusing on the involvement of cellular reduced glutathione (GSH) homeostasis and c-Jun NH(2) -Terminal kinase (JNK). Buthionine sulfoximine (BSO), an inhibitor of cellular GSH biosynthesis, significantly augmented ANDRO-induced cytotoxicity in hepatoma Hep3B and HepG2 cells. BSO depleted cellular GSH, and augmented ANDRO-induced apoptosis, inhibition of colony formation and JNK activation in Hep3B cells. All these effects could be reversed by GSH monoethyl ester (GSH.EE), whose deacetylation replenishes cellular GSH. BSO also augmented ANDRO-induced activation of apoptosis signal-regulating kinase 1 (ASK1), mitogen-activated protein kinase kinase-4 (MKK4) and c-Jun, which are all up-stream or down-stream signals of JNK. Further results showed that JNK inhibitor SP600125 and 420116 both reversed ANDRO-induced cytotoxicity, and SP600125 also decreased ANDRO-increased intracellular GSH and GCL activity. Finally, we showed that in nude mice bearing xenografted Hep3B tumors, BSO improved the inhibition of tumor growth by ANDRO. Taken together, our results suggest that there is a crosstalk between JNK activation and cellular GSH homeostasis, and ANDRO targets this to induce cytotoxicity in hepatoma cells.
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Ji
authors.forename: Kaikai
authors.initials: K
authors.lastname: Shen
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.forename: Grant
authors.initials: G
authors.lastname: Morahan
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Wang
mesh_terms: D035685:Andrographis / Q000378:metabolism; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude
chemical_list: D000893:Anti-Inflammatory Agents; D000964:Antimetabolites, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes; C030419:andrographolide; D019328:Buthionine Sulfoximine; D048031:JNK Mitogen-Activated Protein Kinases; D005978:Glutathione