title: Inhibitory effect of propolis on the growth of human leukemia U937.
abstract: We have investigated the effect of propolis (CB Propolis) on the growth of human histiocytic lymphoma U937 cells. We found that propolis strongly inhibited the growth of the cells and macromolecular synthesis in a dose- and time-dependent manner by apoptosis. Propolis at 0.015-0.5 microl/ml showed antitumor activity with an IC(50) of 0.18 microl/ml for 3 d. It also inhibits DNA, RNA and protein synthesis with an IC(50) of 0.08, 0.17 and 4.3 microl/ml, respectively. The inhibitory effect on DNA synthesis was partially irreversible. Moreover, an apoptotic DNA ladder and chromatin condensation were observed in the same concentration range in which cell growth was inhibited. The caspase inhibitor, Z-Asp-CH(2)-DCB, prevented DNA fragmentation. These results suggest that the antitumor activity of propolis occurs through the induction of apoptosis. Propolis may be useful as a cancer chemopreventive and chemotherapeutic agent.
authors.affiliation: Department of Pharmacology and Toxicology, Cancer Research Institute, Tohoku Pharmaceutical University, Sendai, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Aso
authors.forename: Syu-Ichi
authors.initials: S
authors.lastname: Kanno
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tadano
authors.forename: Susumu
authors.initials: S
authors.lastname: Satoh
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ishikawa
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology* / Q000517:prevention & control*; D011429:Propolis / Q000494:pharmacology*; D020298:U937 Cells
chemical_list: D000970:Antineoplastic Agents; D006131:Growth Inhibitors; D011429:Propolis