Liposomal Preparation Of Curcumin Ⅲ And Its Effects On The Biological Properties Of Human Pulmonary Adenocarcinoma Cell Line A549

Pulmonary carcinoma is one of the commonly encountered malignant tumors in which more than 80% are non-small cell lung cancer (NSCLC). NSCLC has poor sensitivity to radiotherapy and chemotherapy. The growth, recurrence, and metastasis of tumor are the main factors affecting the prognosis.It has indicated that curcuminoids, the main active ingredient in curcuma, has significantly inhibitory effect on various types of tumors. It can influence each phase of the tumor growth(initiation promotion and progression), and has inhibitory effect on infiltration and metastasis by means of inhibition the tumor angiogenesis.Curcuminoids include mainly 3 kinds of active monomes, i.e. curcuminI (curcumin), curcumin II (demethoxycurcumin ), and curcumin Ⅲ (bisdemethoxycurcumin). Previous studies have proved that curcumin Ⅲ has stronger activity in anti-tumor and anti-angiogenesis. However, curcuminoids can not be dissolved in water and can also be oxidized easily in vitro, so venous administration is hard and there has been no drug preparation with good stability. Besides, In vivo studies have revealed that small amount of curcumin can be detected in plasma after oral administration and large amount of curcumin is inactivated by metabolism in gastrointestinal tracts. These bring about difficulties in the clinical application of curcumin. Recent studies have shown that liposome encapsulation technique can be employed to solve the problem that fat-soluble drugs can not be easily dissolved in water. Liposome is also an ideal carrier of anti-tumor drugs. It can decrease the toxicity of the encapsulated drugs and increase the amount of drugs absorbed by highly proliferative tumor cells. Therefore, in this study we applied liposome for the encapsulation of curcumin Ⅲ, and employed pulmonary adenocarcinoma cell line A549 as the object for the study of anti-non small cell lung cancer.The purpose is to exploring the possibility of new preparation of curcumin suitable for venous administration using liposome as a carrier ,and further understanding the effects of curcumin on the biological properties of pulmonary carcinoma cells and to provide proof for the further studies. Methods Extraction and isolation of active monosome of curcumin by the approach of extractionby ethanol→defattednessby Petroleum ether →column chromatography using silicagel→purification by acetone.Liposomal preparation of curcumin Ⅲ by technique of ethanol infusion.The concentration of Curcumin Ⅲ in plasma after venous administration were determined by HPLC. The pharmacokinetic parameters were statistic by 3P87 pharmacokinetic software. Invert microscope and transmission electron microscope were used to observe the changes of A549 cells after treated with liposome-encapsulated curcumin Ⅲ.The IC50 were determined by MTT assays. Flow cytometric analysis were performed to detecte the cell cycle. Cell apoptosis was detected by acridine orange staining and TDT mediated dUTP nick end labeling. RT-PCR were performed to analysis the mRNA expression of bcl-2 gene. Main results as follows:The approach of extraction and isolation of active monosome of curcumin was of satisfactory results, convenient operation, and good reproducibility. The liposome encapsulation rate of curcumin Ⅲ obtained by ethanol infusion technique was 87.89%.Particle sizes were about 130.5nm and well- distributed. Solubility of drugs and in vitro stability were significantly increased as well. Comparison of the pharmacokinetics showed that the eliminate half life (t1/2)of liposome-encapsulated curcumin Ⅲ is 1.22 times higher than that of free curcumin Ⅲ monosome.And the plasma concentration and the drug-time area under the curve (AUC,1.92 times) were increased. More significantly, improvement of solubility and safety makes it possible to increase blood concentration greatly after administration.4. Both liposome-encapsulated curcumin Ⅲ and free curcumin Ⅲ monosome had definite effects on the proliferative activity of human pulmonary adenocarcinoma cell line A549 cultured...