title: Korean red ginseng extract induces apoptosis and decreases telomerase activity in human leukemia cells.
abstract: OBJECTIVE
  Korean red ginseng (KRG, Panax ginseng C.A. Meyer Radix rubra) has been used to treat various diseases including cancer. However, the molecular mechanisms responsible for KRG extract induced apoptosis and telomerase inhibition remain unclear.
  
  
  METHODS
  The hot water extract from KRG was used to evaluate the mechanism of induction of apoptosis in U937 human leukemia cells and its effects on cyclooxgenase-2 (COX-2) and telomerase activity.
  
  
  RESULTS
  KRG extract treatment to U937 cells resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner as measured by hemacytometer counts, MTT assay, fluorescence microscopy, agarose gel electrophoresis and flow cytometry analysis. The increase in apoptosis was associated with the down-regulation of antiapoptotic Bcl-2, Bcl-X(L), and IAPs family members, and the activation of caspase-3. KRG extract treatment also decreased the expression levels of COX-2 and inducible nitric oxide synthase. Furthermore, KRG extract treatment progressively down-regulated the expression of human telomerase reverse transcriptase, a main determinant of the telomerase enzymatic activity, with inhibiting the expression of c-Myc in a concentration-dependent manner.
  
  
  CONCLUSIONS
  These results provide important new insights into the possible molecular mechanisms of the anticancer activity of KRG extract.
authors.affiliation: Department of Pharmacy (BK21 Program), Research Institute for Drug Development, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Park
authors.forename: Cheol
authors.initials: C
authors.lastname: Park
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Mohammad Akbar
authors.initials: MA
authors.lastname: Hossain
authors.forename: Min Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Hae Young
authors.initials: HY
authors.lastname: Chung
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Son
authors.forename: Gi-Young
authors.initials: GY
authors.lastname: Kim
authors.forename: Yung Hyun
authors.initials: YH
authors.lastname: Choi
authors.forename: Nam Deuk
authors.initials: ND
authors.lastname: Kim
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D051546:Cyclooxygenase 2 / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy / Q000378:metabolism; D055670:Medicine, Korean Traditional; D008856:Microscopy, Fluorescence; D005894:Panax / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D016271:Proto-Oncogene Proteins c-myc / Q000187:drug effects; D019098:Telomerase / Q000187:drug effects* / Q000378:metabolism; D020298:U937 Cells
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D016271:Proto-Oncogene Proteins c-myc; D051546:Cyclooxygenase 2; D019098:Telomerase