title: Aqueous extract of Rhodiola imbricata rhizome inhibits proliferation of an erythroleukemic cell line K-562 by inducing apoptosis and cell cycle arrest at G2/M phase.
abstract: Rhodiola imbricata is a medicinal plant having immunostimulating properties. The anti-proliferative effects of Rhodiola aqueous extract (RAE), were studied in human erythroleukemic cell line K-562 using MTT cell proliferation assay. The proliferation of K-562 was significantly decreased after 72h incubation with RAE at 100 and 200microg/ml. However, almost no suppressive effects could be detected in normal human peripheral blood lymphocytes or mouse macrophage cell line RAW-264.7. RAE was also found to induce intracellular reactive oxygen species (ROS) in K-562 cells at 200microg/ml when incubated overnight. The increased ROS generation may cause apoptosis, which was observed in AnnexinV-FITC and propidium iodide (PI) staining of cells treated with RAE for 72h in K-562 cells. Moreover, RAE arrested cell cycle progression in G2/M phase in early and late period of exposure. The anti-cancer activity of RAE was also confirmed by increased NK cell cytotoxicity. These observations suggest that aqueous extract of R. imbricata rhizome has very potent anti-cancer activities, which might be useful in leukemia cancer treatment.
authors.affiliation: Immunomodulation Laboratory, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi-110054, India.
authors.forename: K P
authors.initials: KP
authors.lastname: Mishra
authors.forename: Y S
authors.initials: YS
authors.lastname: Padwad
authors.forename: A
authors.initials: A
authors.lastname: Dutta
authors.forename: L
authors.initials: L
authors.lastname: Ganju
authors.forename: M
authors.initials: M
authors.lastname: Sairam
authors.forename: P K
authors.initials: PK
authors.lastname: Banerjee
authors.forename: R C
authors.initials: RC
authors.lastname: Sawhney
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D016195:G2 Phase / Q000187:drug effects; D006801:Humans; D020014:K562 Cells; D004915:Leukemia, Erythroblastic, Acute / Q000188:drug therapy*; D010936:Plant Extracts / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000032:analysis; D027343:Rhizome / Q000737:chemistry*; D029771:Rhodiola / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D014867:Water