title: Synergistic effect of oridonin and cisplatin on cytotoxicity and DNA cross-link against mouse sarcoma S180 cells in culture.
abstract: Oridonin (Ori) is an active principle isolated from Rabdosia rubescens. The cytotoxic effect of the combination of Ori and cisplatin was tested by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay. IC50 of cisplatin to cultured S180 cells in 24 h was 9.38 micrograms.ml-1. When the cells were treated with cisplatin plus Ori 0.5 and 1 microgram.ml-1, the IC50 were 1/3.4 and 1/6.7, respectively, of that with cisplatin alone. Modified alkaline elution was used to detect the DNA interstrand cross-link and DNA-protein cross-link in S180 cells induced by the 2 drugs. A greater amount of DNA cross-link was detected when the cells were treated with cisplatin plus Ori than with cisplatin alone (P < 0.05). After lysis by proteinase K, a reduction in DNA cross-link was seen, which suggested that the drugs could produce both kinds of DNA cross-link.
authors.affiliation: Department of Pharmacology, He-nan Institute of Medical Sciences, Zhengzhou, China.
authors.forename: Z G
authors.initials: ZG
authors.lastname: Gao
authors.forename: Q X
authors.initials: QX
authors.lastname: Ye
authors.forename: T M
authors.initials: TM
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002945:Cisplatin / Q000494:pharmacology*; D004273:DNA, Neoplasm / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology*; D045786:Diterpenes, Kaurane; D004357:Drug Synergism; D051379:Mice; D012510:Sarcoma 180 / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004273:DNA, Neoplasm; D004224:Diterpenes; D045786:Diterpenes, Kaurane; C011959:oridonin; D002945:Cisplatin