title: Nanoparticulate Quillaja saponin induces apoptosis in human leukemia cell lines with a high therapeutic index.
abstract: Saponin fractions of Quillaja saponaria Molina (QS) have cytotoxic activity against cancer cells in vitro, but are too toxic to be useful in the clinic. The toxic effect was abolished by converting QS fractions into stable nanoparticles through the binding of QS to cholesterol. Two fractions of QS were selected for particle formation, one with an acyl-chain (ASAP) was used to form killing and growth-inhibiting (KGI) particles, and the other without the acyl-chain (DSAP) was used to formulate blocking and balancing effect (BBE) particles. KGI showed significant growth inhibiting and cancer cell-killing activities in nine of 10 cell lines while BBE showed that on one cell line. The monoblastoid lymphoma cell line U937 was selected for analyzing the mode of action. Low concentrations of KGI (0.5 and 2 microg/mL) induced irreversible exit from the cell cycle, differentiation measured by cytokine production, and eventually programmed cell death (apoptosis). Compared to normal human monocytes, the U937 cells were 30-fold more sensitive to KGI. The nontoxic BBE blocked the cell killing effect of KGI in a concentration-dependent manner. In conclusion, the formulation of QS into nanoparticles has the potential of becoming a new class of anticancer agents.
authors.affiliation: Department of Medical Sciences, Section of Virology, Uppsala University, Uppsala, Sweden.
authors.forename: Kefei
authors.initials: K
authors.lastname: Hu
authors.forename: Saideh
authors.initials: S
authors.lastname: Berenjian
authors.forename: Rolf
authors.initials: R
authors.lastname: Larsson
authors.forename: Joachim
authors.initials: J
authors.lastname: Gullbo
authors.forename: Peter
authors.initials: P
authors.lastname: Nygren
authors.forename: Tanja
authors.initials: T
authors.lastname: Lövgren
authors.forename: Bror
authors.initials: B
authors.lastname: Morein
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry; D017209:Apoptosis / Q000187:drug effects*; D004339:Drug Compounding / Q000379:methods; D006801:Humans; D019169:Jurkat Cells; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry*; D010316:Particle Size; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry*; D031990:Quillaja / Q000737:chemistry*; D016896:Treatment Outcome; D020298:U937 Cells
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts