title: Induction of apoptosis in human promyelocytic leukemia HL60 cells by an extract from Erythrina suberosa stem bark.
abstract: In this study, the apoptosis-inducing effect of an alcoholic extract from Erythrina suberosa stem bark (ESB) was investigated using human promyelocytic leukemia HL60 cells. Cell viability was estimated by MTT assay. We found that the ESB inhibited cell proliferation in a dose- and time-dependent manner. A series of well-documented morphological changes, such as cell shrinkage, condensation of nuclear chromatin, and nuclear fragmentation, were observed by fluorescence microscopy. The gold standard scanning electron micrographs showed apoptotic bodies and formation of blebs. Cell cycle analysis showed a significant increase in Sub G(0) population of cells above 50 μg/ml. ESB treatment resulted in a dose-dependent increase in annexin V positive cells. Increase in intracellular ROS production up to sixfold was detected in ESB-treated HL60 cells by DCFH-DA assay. Dissipation of mitochondrial membrane potential of intact cells accompanied by increase in cytosolic cytochrome c was observed, which was followed by activation of caspase-9 and -3 but not caspase-8. DNA fragmentation analysis revealed typical ladders as early as 18 h indicative of caspase-3 role in the apoptotic pathway. The overall results suggest that ESB induces mitochondria-mediated intrinsic apoptotic pathway in HL60 cells and might have therapeutic value against human leukemia.
authors.affiliation: Cancer Pharmacology Division, Indian Institute of Integrative Medicine, Jammu, India. satyamka@gmail.com
authors.forename: Satyam Kumar
authors.initials: SK
authors.lastname: Agrawal
authors.forename: Madhunika
authors.initials: M
authors.lastname: Agrawal
authors.forename: Parduman Raj
authors.initials: PR
authors.lastname: Sharma
authors.forename: Bishan Datt
authors.initials: BD
authors.lastname: Gupta
authors.forename: Saroj
authors.initials: S
authors.lastname: Arora
authors.forename: Ajit Kumar
authors.initials: AK
authors.lastname: Saxena
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation; D004895:Erythrina / Q000737:chemistry*; D018922:HL-60 Cells; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008517:Phytotherapy; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018547:Plant Stems / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000187:drug effects
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D020169:Caspases