Turan Nevruz, Akgün-Dar Kadriye, Kuruca Serap Erdem, Kiliçaslan-Ayna Tülay, Seyhan Vildan G, Atasever Belkis, Meriçli Filiz, Carin Mahmut
Istanbul University, Faculty of Science, Department of Biology, Vezneciler, Istanbul, Turkey.
J Exp Ther Oncol. 2006;6(1):31-8.
Nerium oleander (No), is a toxic plant. In recent studies, it was determined that the extracts of this plant are effective to treat some types of cancer, but these studies are limited and do not include human leukemia. In the present study, firstly we aimed to investigate in vitro the cytotoxic effects of No on the HL60 and K562 leukemia cell lines. The cells were incubated with six different concentrations of each three extracts. MTT assay was employed as a cytotoxicity test. It was observed that concentrations of 1000, 500 and 50 microg/ml from each extract possess marked antileukemic effects. No leaf and root extracts were seen to be more cytotoxic than the stem extract according to LC50. Secondly, in order to understand the role of P-gp in cytotoxicity, P-gp levels of K562 resistant and sensitive cells were measured by flow cytometry before treatment extracts, and then, the cells were incubated with No leaf, stem and root extracts in 500 microg/ml concentrations overnight. After incubation, measurements showed decreased levels of P-gp in the cells. Hence, it is possible to think contributes to their cytotoxic effects that inhibiting of the P-gp pump by No extracts on leukemia cell lines.
夹竹桃（Nerium oleander，No）是一种有毒植物。在最近的研究中，已确定该植物的提取物对某些类型的癌症有效，但这些研究有限，且未包括人类白血病。在本研究中，首先我们旨在体外研究夹竹桃对HL60和K562白血病细胞系的细胞毒性作用。将细胞与每种三种提取物的六种不同浓度孵育。采用MTT法作为细胞毒性试验。观察到每种提取物的1000、500和50微克/毫升浓度具有明显的抗白血病作用。根据半数致死浓度（LC50），夹竹桃叶和根提取物比茎提取物的细胞毒性更强。其次，为了了解P-糖蛋白在细胞毒性中的作用，在处理提取物之前，通过流式细胞术测量K562耐药和敏感细胞的P-糖蛋白水平，然后将细胞与500微克/毫升浓度的夹竹桃叶、茎和根提取物孵育过夜。孵育后，测量结果显示细胞中P-糖蛋白水平降低。因此，可以认为夹竹桃提取物对白血病细胞系中P-糖蛋白泵的抑制作用有助于其细胞毒性作用。
