Gao Z G, Ye Q X, Zhang T M
Department of Pharmacology, He-nan Institute of Medical Sciences, Zhengzhou, China.
Zhongguo Yao Li Xue Bao. 1993 Nov;14(6):561-4.
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.
冬凌草甲素（Ori）是从冬凌草中分离出的一种活性成分。通过MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑]比色法检测了冬凌草甲素与顺铂联合使用的细胞毒性作用。顺铂对培养的S180细胞24小时的半数抑制浓度（IC50）为9.38微克/毫升。当细胞用顺铂加0.5和1微克/毫升的冬凌草甲素处理时，IC50分别为单独使用顺铂时的1/3.4和1/6.7。采用改良碱性洗脱法检测两种药物诱导的S180细胞中的DNA链间交联和DNA-蛋白质交联。当细胞用顺铂加冬凌草甲素处理时，检测到的DNA交联量比单独用顺铂处理时更多（P < 0.05）。经蛋白酶K裂解后，DNA交联减少，这表明药物可产生两种类型的DNA交联。
