[Oridonin induced U937 cell apoptosis through ERK pathway].
OBJECTIVE
To study the mechanisms of oridonin-induced U937 cell apoptosis, and to examine the role of ERK MAPK.


METHODS
MTT, Hoechst 33258 staining, DNA agarose gel electrophoresis and Western blot analysis were used.


RESULTS
Oridonin inhibited U937 cell growth in a time- and dose-dependent manner. Apoptotic bodies were found with Hoechst 33258 staining after treatment with 27 micromol x L(-1) oridonin. Simultaneously, ERK phosphorylation was significant. ERK inhibitor PD98059 partially blocked the growth-inhibitory effect as well as DNA fragmentation. The expression of antiapoptotic mitochondrial protein Bcl-XL decreased time-dependently, and that of proapoptotic protein Bax increased. However, PD98059 reversed the effect of oridonin on Bcl-XL and Bax.


CONCLUSIONS
Oridonin induces U937 cell apoptosis through activation of ERK and alteration of the ratio of Bax/Bcl-XL.
Liu
Yan-qiu
YQ
China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, China.
You
Song
S
Tashiro
Shin-ichi
S
Onodera
Satoshi
S
Ikejima
Takashi
T
D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D004224:Diterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D045786:Diterpenes, Kaurane / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D037602:Isodon / Q000737:chemistry; D010766:Phosphorylation; D010946:Plants, Medicinal / Q000737:chemistry; D020298:U937 Cells; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
D004224:Diterpenes; D045786:Diterpenes, Kaurane; D005419:Flavonoids; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; C011959:oridonin; D048049:Extracellular Signal-Regulated MAP Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one