title: JR6, a new compound isolated from Justicia procumbens, induces apoptosis in human bladder cancer EJ cells through caspase-dependent pathway.
abstract: BACKGROUND
  Numerous efforts have been conducted in searching for effective agents against cancer, in particular from herbal medicines. Justicia procumbens is a traditional herbal remedy which was produced in the south-western and southern provinces of China and Taiwan province used to treat fever, pain, and cancer. Here, we identified a new compound 6'-hydroxy justicidin A (JR6) from Justicia procumbens, which showed obvious anti-cancer effects.
  
  
  METHODS
  The cytotoxicity activity was assayed using MTT and SRB. Intracellular ROS visualization and quantification were acquired by using a laser scanning confocal microscopy. Apoptosis was measured using a propidium iodide (PI) apoptosis detection kit by flow cytometry. Activation of caspases (caspase-3, caspase-8, and caspase-9) was evaluated respectively using GloMax luminescence detector and Caspase-Glo 3,8,9 assay kits. Loss of mitochondrial membrane potential was observed by microscopy using JC-1 dye. Quantitative real-time PCR analysis was employed to detect the expression of protein associated with cell death.
  
  
  RESULTS
  JR6 remarkably inhibited growth in human bladder cancer EJ cells by decreasing cell proliferation, reduced the SOD activity, increased the content of reactive oxygen species (ROS), and induced apoptosis. Activation of caspase-8, caspase-9, and the subsequent activation of caspase-3 indicated that JR6 may be inducing intrinsic and extrinsic apoptosis pathways. Caspase-3, caspase-8, and caspase-9 inhibition rendered this extract ineffective, thus JR6-induced apoptosis is caspase-dependent. JR6 also disrupted the mitochondrial membrane potential (Δψm) and unregulated the Bax and p53 expressions in EJ cells.
  
  
  CONCLUSIONS
  These observations suggest that JR6 induce apoptosis through caspase-dependent pathway in human bladder cancer EJ cells, emphasizing the importance of this traditional medicine and thus presents a potential novel alternative to bladder cancer therapy.
authors.affiliation: Research Center for Pharmacology and Toxicology, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: He
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Xian-Zhe
authors.initials: XZ
authors.lastname: Dong
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Yang
authors.forename: Shi-Lin
authors.initials: SL
authors.lastname: Chen
authors.forename: Ming-Gang
authors.initials: MG
authors.lastname: Bi
mesh_terms: D027901:Acanthaceae; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D017705:Lignans / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D001749:Urinary Bladder Neoplasms; D051028:bcl-2-Associated X Protein / Q000235:genetics
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C494828:Bax protein, rat; D017705:Lignans; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; C571611:6'-hydroxyjusticidin A; D020169:Caspases