Effect of oridonin, a Rabdosia diterpenoid, on radiosensitization with misonidazole.
The radiosensitization brought about by oridonin, one of the Rabdosia diterpenoids, alone or in combination with misonidazole, was investigated in Chinese hamster V79 cells. The enhancement ratio of 1.92 was obtained when 0.01 mM oridonin and 1 mM misonidazole were administered to hypoxic cells under radiation. The enhancement ratios of oridonin and misonidazole for hypoxic cells were 1.16 and 1.59 respectively. Hence, a supra-additive effect was obtained by the combined treatment with these two drugs. Under aerobic conditions, no effect of 0.01 mM oridonin on the radiosensitization caused by misonidazole was observed.
Department of Radiation Oncology, School of Medicine, Tokai University, Isehara, Japan.
C
C
Murayama
Y
Y
Nagao
S
S
Sano
M
M
Ochiai
K
K
Fuji
E
E
Fujita
T
T
Mori
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006224:Cricetinae; D004224:Diterpenes / Q000494:pharmacology*; D045786:Diterpenes, Kaurane; D004357:Drug Synergism; D008920:Misonidazole / Q000494:pharmacology*; D010944:Plants / Q000032:analysis*; D011836:Radiation Tolerance; D011838:Radiation-Sensitizing Agents
D004224:Diterpenes; D045786:Diterpenes, Kaurane; D011838:Radiation-Sensitizing Agents; C011959:oridonin; D008920:Misonidazole