Inhibition Of Curcuma Essential Oil On Human Lung Cancer Cells And Neovascularization

Lung cancer is one of the most common malignant tumors, seriously threatening the human life. However, there is no satisfactory treatment for lung cancer currently. Therefore, looking for safe and effective medicine is the most important topic in oncotherapy. In recent years, more and more kinds of synthetic chemistry material are produced on the earth and threat resulting from oncogenic materials becomes more seriously. Therefore, it is an important task to look for effective anticancer composition from plants. Making good use of abundant resources of plants in our country and developing new anticancer medicine have become increasingly important. Curcuma, the dry rootstock of the plant turmeric, is one of the most common Chinese materia medica. Curcuma essential oil and Curcuminoids are most useful components of Curcuma. Curcuma essential oil has many advantages such as abundance resource, cheap price, being distilled conveniently, without any side effect. Previous study show, as the major useful component of curcuma of the curcuma genus, curcuma essential oil has various effects such as anti-bacterium, anti-inflammation, removing phlegm, relieving a cough and calming asthma. In recent few years, more and more experts are interested in anticancer effect of Curcuma essential oil. It has been reported that Curcuma essential oil can inhibit people's acute leukemia cell line HL-60 and liver blast cell cancer cell line HepG2 proliferation and promote rat spleen cells proliferation [5]. However, at present, no literatures have been reported about effect of curcuma essential oil on lung cancer. Folkman considered that two kind of cell mass have effect on tumorous growth in concomitance, one is hyperactive mutation rate tumor cell mass and the other is low mutation rate endothelial cell mass. The two cell mass grows by stimulating each other through paracrine. Therefore, to treat on two cells mass maybe more useful than simply on tumor cell mass. In our study, we investigate effect of curcuma essential oil on lung cancer cells and on angiogenesis, explore the possible mechanism, and offer experimental evidence of anticancer effect of curcuma essential oil. The main contents of our study are as follows: 1. Effect of curcuma essential oil on human lung adenocarcinoma cells line (A549) (1) To detect effects of curcuma essential oil on proliferation of A549 cells in vitro by MTT assay. (2) To investigate morphological changes of A549 cells with Inversion microscope, Giemsa staining, Acridine orange staining, Transmission electron microscope and Flow cytometry after administration of curcuma essential oil. 2. Inhibition of curcuma essential oil on neovascularization (1) To analyze the inhibitory effects of curcuma essential oil on human pulmonary microvascular endothelial cell (HPMEC) by MTT trial. (2) To investigate morphological changes of human lung microvascular endothelial cells with Inversion microscope, Giemsa staining and Acridine orange staining after administration of curcuma essential oil. (3) To observe the effect of curcuma essential oil on lung cancer cells induced tubular morphogenesis of endothelial cells. (4) The chicken chorioallantoic membrane (CAM) assay was used to detect the effect of curcuma essential oil on angiogenesis. (5) To observe the effect of curcuma essential oil on angiogenesis enhancing factor such as vessel endothelium growth factor (VEGF) and basic fibroblast growth factor (bFGF) synthesized by A549 cells with immuocytochemistry. Main results 1. Curcuma essential oil may inhibit proliferation of A549 cells with obvious dose-effect relationship. Concentration of curcuma essential oil to inhibit A549 cells proliferation and to induce apoptosis is higher than that of curcuma essential oil on HPMEC. The half inhibiting concentration IC (IC50) of curcuma essential oil used on A549 cells is 1.7μl/ml and the half inhibiting concentration IC (IC50) of curcuma essential oil uses on HPMEC is 0.65μl/ml. 2. Curcuma essential oil effect on A549 cells and HPMEC can occurrence typical apoptosis morphocytology character, can find karyopyknosis, chromosome agglomeration, form apoptotic body and so on. 3. Flow cytometry show that apoptosis maybe observed 48h after administration of curcuma essential oil in A549 cells. Apoptosis proportion will be higher with the increaseconcentration of curcuma essential oil. Cycle was inhibited in S period. 4. Canaliculization is decreased more obviously than control group in combination culture 6 days after concentration of curcuma essential oil above or equal 0.6μl/ml(p<0.01). 5. Curcuma essential oil inhibited blood vessel formation in chicken chorioallantoic membrane when concentration of curcuma essential oil above or equal 0.2μl/ml. Difference is significant(p<0.01). 6. According to the results of immuocytochemistry and image analysis technique, Curcuma essential oil could inhibit VEGF and bFGF albumen expression in A549 cells(p<0.05). Conclusion: 1. Curcuma essential oil can inhibit A549 cells multiplication, with dose-effect and time-effect relationship. It may have therapertical effect on lung cancer at clinical. 2. Curcuma essential oil can induce apoptosis of A549 cells and inhibit cycle of A549 cells at S stage. It indicates that its anticancer mechanism may be closely associated with apoptosis. 3. The concentration of curcuma essential oil inhibiting A549 cells multiplication and inducing apoptosis is obviously higher than that of curcuma essential oil on HPMEC. It indicated that curcuma essential oil can inhibit both tumor cell mass and endothelial cell mass, which may have dual effection on antineoplastic action. 4. Curcuma essential oil can obviously inhibit both angiogenesis induced by tumor cells, and angiogenesis of chick embryo allantocherion, which may be concerned with inhibition of angiogenesis enhancing factor such as VEGF bFGF, prevention of vascular endothelial cell proliferation and induction of apoptosis.