title: Hedyotis diffusa Willd extract inhibits the growth of human glioblastoma cells by inducing mitochondrial apoptosis via AKT/ERK pathways.
abstract: BACKGROUND
  Hedyotis diffusa Willd (Rubiaceae) (HDW) has been widely applied for the treatment of tumors, inflammation and toxication in traditional Chinese medicine. The antitumor effect of HDW on glioblastoma has been rarely reported. We aim to evaluate the activity of this extract and explore the underlying mechanism in U87 human glioblastoma cell line.
  
  
  METHODS
  Cytotoxicity of HDW extract on U87 cells was measured by MTT assay. Apoptosis, cell cycle arrest and mitochondrial membrane potential (MMP) collapse induced by HDW extract were determined by flow cytometry. Caspase activity was analyzed based on colorimetric assay with a microplate spectrophotometer. Protein expression was examined by Western blot.
  
  
  RESULTS
  HDW extract suppressed U87 cells growth in a dose- and time-dependent manner. Flow cytometry showed that HDW extract induced significant apoptosis, S/G2-M phase arrest and MMP collapse in U87 cells. Furthermore, dose-dependent activation of caspase-3, Bcl-2, Bax and ERK was observed with HDW extract treatment. Decreased Bcl-2/Bax ratio and Akt suppression were readily found as well.
  
  
  CONCLUSIONS
  Induction of mitochondria-mediated apoptosis played an essential role in antitumor activity of HDW extract in U87 cells, in which ERKs and Akt signaling proteins were also involved. These findings contributed to the feasibility of using HDW extract in glioblastoma treatment and the understanding of the molecular mechanism.
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Rui-Fan
authors.initials: RF
authors.lastname: Xie
authors.affiliation: Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Qun-Gen
authors.initials: QG
authors.lastname: Xiao
authors.affiliation: Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Shen
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China. Electronic address: zhuxingenvip@163.com.
authors.forename: Xin-Gen
authors.initials: XG
authors.lastname: Zhu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001932:Brain Neoplasms / Q000201:enzymology / Q000473:pathology*; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005434:Flow Cytometry; D005909:Glioblastoma / Q000201:enzymology / Q000473:pathology*; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D010936:Plant Extracts; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019666:Rubiaceae / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Apoptosis; Glioblastoma; Hedyotis diffusa Willd; Mitochondrial membrane