Induction of apoptosis by pterocarpans from Platymiscium floribundum in HL-60 human leukemia cells.
(+)-2,3,9-Trimethoxy-pterocarpan (1) (+)-3,9-dimethoxy-pterocarpan [(+)-homopterocarpin] (2), (+)-3-hydroxy-9-methoxy-pterocarpan [(+)-medicarpin] (3) and (+)-3,4-dihydroxy-9-methoxy-pterocarpan [(+)-vesticarpan] (4) are cytotoxic pterocarpans isolated from the native Brazilian plant Platymiscium floribundum. The purpose of the present study was to examine whether induction of apoptosis and/or inhibition of DNA synthesis is involved in the cytotoxicity of these pterocarpans in human leukemia cells. The effect on cell viability determined using the trypan exclusion assay revealed that all compounds tested reduced the number of viable cells, while only in the presence of 3 and 4, there was an increase of nonviable cells. The analysis of membrane integrity and morphological modifications by flow cytometry in the presence of these two compounds indicated that treated cells undergo necrosis, while 1 and 2 trigger apoptosis. DNA synthesis seemed to be affected since BrdU incorporation was inhibited in a dose-dependent manner in the presence of all tested compounds. Pterocarpan treatment also induced an increase in the amount of subdiploid DNA, indicating internucleosomal DNA breakdown, mitochondrial depolarization and caspase-3 activation, which indicate apoptosis induction.
Militão
Gardenia C G
GC
Laboratório de Oncologia Experimental, Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, P.O. Box-3157, 60430-270 Fortaleza, Ceará, Brazil.
Dantas
Ivana N F
IN
Pessoa
Cláudia
C
Falcão
Maria José C
MJ
Silveira
Edilberto R
ER
Lima
Mary Anne S
MA
Curi
Rui
R
Lima
Thaís
T
Moraes
Manoel O
MO
Costa-Lotufo
Letícia V
LV
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001938:Brazil; D053148:Caspase 3; D061945:Caspase Inhibitors; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D004273:DNA, Neoplasm / Q000096:biosynthesis; D003864:Depression, Chemical; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D009707:Nucleosomes / Q000187:drug effects / Q000648:ultrastructure; D010946:Plants, Medicinal / Q000737:chemistry; D036343:Pterocarpans / Q000494:pharmacology*; D014343:Trypan Blue; D014934:Wood
D000972:Antineoplastic Agents, Phytogenic; D061945:Caspase Inhibitors; D004273:DNA, Neoplasm; D009707:Nucleosomes; D036343:Pterocarpans; C505407:CASP3 protein, human; D053148:Caspase 3; D014343:Trypan Blue