Oridonin enhances phagocytosis of UV-irradiated apoptotic U937 cells.
We previously reported that oridonin, a major component isolated from the plant Rabdosia rubescens HEMSL, induced apoptosis in human melanoma A375-S2 and cervical cancer HeLa cells. In the present study, oridonin was first evaluated for its effect on phagocytosis of apoptotic cells by macrophages. Preincubation of human histocytic lymphoma U937 cell-derived macrophages with 2.7 microM oridonin significantly augmented phagocytosis of UV-irradiated (2.4 J/cm2, 4 min) U937 cells undergoing apoptosis in a dose- and time-dependent manner. However, less effect on synthetic fluoresbrite microspheres indicated that enhancement of apoptotic U937 cell uptake by oridonin was a selective effect. The oridonin-augmented phagocytosis was attenuated by anti-human TNFalpha and IL-1beta antisera, suggesting that TNFalpha and IL-1beta participate in the phagocytosis by oridonin-treated U937 cell-derived macrophages. In addition, the similar effect of phagocytosis was observed in oridonin-treated human monocyte-derived macrophages at 4 d maturation. Taken together, oridonin facilitates the phagocytic activity against apoptotic cells through TNFalpha and IL-1beta release, which may be contribute to its antitumor activities.
Liu
Yan-Qiu
YQ
China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang, China.
You
Song
S
Zhang
Chun-Ling
CL
Tashiro
Shin-Ichi
S
Onodera
Satoshi
S
Ikejima
Takashi
T
D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D002478:Cells, Cultured; D004224:Diterpenes / Q000494:pharmacology*; D045786:Diterpenes, Kaurane; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009000:Monocytes / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D010587:Phagocytosis / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D020298:U937 Cells; D014466:Ultraviolet Rays
D004224:Diterpenes; D045786:Diterpenes, Kaurane; C011959:oridonin