Retama monosperma n-hexane extract induces cell cycle arrest and extrinsic pathway-dependent apoptosis in Jurkat cells.
BACKGROUND
Retama monosperma L. (Boiss.) or Genista monosperma L. (Lam.), locally named as "R'tam", is an annual and spontaneous plant belonging to the Fabaceae family. In Morocco, Retama genus is located in desert regions and across the Middle Atlas and it has been widely used in traditional medicine in many countries. In this study, we show that Retama monosperma hexane extract presents significant anti-leukemic effects against human Jurkat cells.


METHODS
Human Jurkat cells, together with other cell lines were screened with different concentrations of Retama monosperma hexane extract at different time intervals. Growth inhibition was determined using luminescent-based viability assays. Cell cycle arrest and apoptosis were measured by flow cytometry analysis. Combined caspase 3 and 7 activities were measured using luminometric caspase assays and immunoblots were performed to analyze expression of relevant pro- and anti-apoptotic proteins. GC-MS were used to determine the chemical constituents of the active extract.


RESULTS
Retama monosperma hexane extract (Rm-HE) showed significant cytotoxicity against Jurkat cells, whereas it proved to be essentially ineffective against both normal mouse fibroblasts (NIH3T3) and normal lymphocytes (TK-6). Cytometric analysis indicated that Rm-HE promoted cell cycle arrest and apoptosis induction accompanied by DNA damage induction indicated by an increase in p-H2A.X levels. Rm-HE induced apoptosis was partially JNK-dependent and characterized by an increase in Fas-L levels together with activation of caspases 8, 3, 7 and 9, whereas neither the pro-apoptotic nor anti-apoptotic mitochondrial membrane proteins analyzed were significantly altered. Chemical identification analysis indicated that α-linolenic acid, campesterol, stigmasterol and sitosterol were the major bioactive components within the extract.


CONCLUSIONS
Our data suggest that bioactive compounds present in Rm-HE show significant anti leukemic activity inducing cell cycle arrest and cell death that operates, at least partially, through the extrinsic apoptosis pathway.
Lamiae
L
Belayachi
Clara
C
Aceves-Luquero
Nawel
N
Merghoub
Youssef
Y
Bakri
Silvia
S
Fernández de Mattos
Saaïd
S
Amzazi
Cancer Cell Biology Group, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Edifici Cientificotècnic, Ctra Km 7,5, Valldemossa, Illes Balears, Spain. priam.villalonga@uib.es.
Priam
P
Villalonga
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D020169:Caspases / Q000378:metabolism*; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002784:Cholesterol / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D007887:Fabaceae / Q000737:chemistry*; D053222:Fas Ligand Protein / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D015458:Leukemia, T-Cell / Q000188:drug therapy* / Q000378:metabolism; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D010840:Phytosterols / Q000494:pharmacology / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D015398:Signal Transduction / Q000187:drug effects; D012855:Sitosterols / Q000494:pharmacology / Q000627:therapeutic use; D013265:Stigmasterol / Q000494:pharmacology / Q000627:therapeutic use; D017962:alpha-Linolenic Acid / Q000494:pharmacology / Q000627:therapeutic use
D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D053222:Fas Ligand Protein; D010840:Phytosterols; D010936:Plant Extracts; D012855:Sitosterols; D017962:alpha-Linolenic Acid; C021273:campesterol; C025473:gamma-sitosterol; D002784:Cholesterol; D013265:Stigmasterol; D048670:MAP Kinase Kinase 4; D053148:Caspase 3; D020169:Caspases