Protective effect of tetrandrine on normal human mononuclear cells against ionizing irradiation.
Tetrandrine, an alkaloid isolated from the plant Stephania tetrandra, at low concentration (2 micrograms/ml) was shown to protect normal human mononuclear cells in vitro against damage due to a single high-dose of ionizing irradiation (10 Gy). The cell survival rate increased from 58.3 +/- 2.2% in the irradiated group to 78.0 +/- 2.6% in the tetrandrine-pretreated group, and similarly, the percentage of necrotic cells declined from 20.7 +/- 2.5% to 10.7 +/- 1.9%, respectively. This protective effect of tetrandrine for cell surviving fraction increased in a dose-dependent manner. Tetrandrine was also found to inhibit inflammatory responses induced by irradiation including the release of superoxide (NBT [nitroblue tetrazolium] reduction decreased from 21.3 +/- 2.3% to 10.2 +/- 2.5%) and phagocytic activity (decreased from 80.7 +/- 3.8% to 50.7 +/- 2.3%, the same range level as that of the control group). However, the alkaloid demonstrated no effect on the production of nitric oxide. In terms of cell morphology, only two types were observed-normal or necrotic cells, and there were no characteristics of programmed cell death. These results indicate that tetrandrine possesses radioprotective activity against 10 Gy of ionizing irradiation and could suppress irradiation-induced inflammatory processes.
Chen
Y J
YJ
Department of Radiation Oncology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China.
Tu
M L
ML
Kuo
H C
HC
Chang
K H
KH
Lai
Y L
YL
Chung
C H
CH
Chen
M L
ML
D000470:Alkaloids / Q000494:pharmacology*; D044182:Benzylisoquinolines; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D009569:Nitric Oxide / Q000096:biosynthesis; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D010084:Oxidation-Reduction; D010587:Phagocytosis / Q000187:drug effects; D011839:Radiation, Ionizing; D011837:Radiation-Protective Agents
D000470:Alkaloids; D044182:Benzylisoquinolines; D011837:Radiation-Protective Agents; D009580:Nitroblue Tetrazolium; C009438:tetrandrine; D009569:Nitric Oxide