類薑黃素之經皮輸送與乳癌治療之潛力：微脂粒劑型與離子電透技術之協同促進效果

Transdermal Delivery of Curcuminoids: Facilitation by Liposome and Iontophoresis and Potential for Breast Cancer Treatment

楊偉德(Wei-Te Yang)

指導教授 ： 簡逸文

高雄醫學大學/藥學院/藥學研究所/碩士(2007年)

摘要

類薑黃素（curcuminoids）是由Curcuma longa L.之根莖中所分離出來的主要活性成分，類薑黃素具有抗腫瘤、抗發炎、抗菌等生物活性。根據近年來的許多研究結果指出，類薑黃素對於MCF-7、MDA-MB-231等乳癌細胞株具有抑制癌細胞生長與誘導其細胞凋亡（apoptosis）的作用，因此類薑黃素具有發展成為治乳癌藥物的潛力。
本研究是以類薑黃素作為模式藥物（model drug），並且利用一新穎且具生物可分解性的微脂粒（liposome）作為類薑黃素的藥物載體（drug carrier）來做為乳癌治療藥物。在微脂粒組成成分－磷脂質（phospholipids）與膽固醇（cholesterol）處方評估實驗中，選擇以DMPC（dimyristoylphosphocholine）：cholesterol之molar ratio為1：1來製備本研究的微脂粒處方。
　　為了研究類薑黃素以微脂粒包覆後對於乳癌細胞株毒殺效果的影響，分別選擇三種乳癌細胞株（MCF-7、MDA-MB-435S與MDA-MB-231）並且以MTT試驗來觀察微脂粒包覆之類薑黃素（liposome-encapsulated curcuminoids）對於三種乳癌細胞之毒殺效果。研究結果顯示，隨著微脂粒包覆之類薑黃素濃度增加時，乳癌細胞之存活率隨之降低；且發現其半致死濃度(IC50)比無微脂粒包覆之類薑黃素之IC50還要低。此外也由於微脂粒劑型的包覆，使得類薑黃素對於乳癌細胞生長抑制的效果更加延長。另外從乳癌細胞萃取薑黃素的高效液態管柱層析法(HPLC)分析實驗結果顯示，確實可利用HPLC方法來定量乳癌細胞中之薑黃素，以及薑黃素的確被乳癌細胞攝入，且細胞攝入程度隨類薑黃素濃度提高而增加。而經由微脂粒的包覆亦可提升薑黃素之細胞攝入，當利用共軛焦顯微鏡去觀察細胞攝入微脂粒處方的情況，也發現相符合的結果。由以上實驗結果我們得知當利用微脂粒包覆類薑黃素時確實可促進乳癌細胞對於薑黃素之攝入（cellular uptake）。
　　本研究也利用離子電透法（iontophoresis）來探討促進微脂粒包覆類薑黃素（liposome-encapsulated curcuminoids）之經皮輸送的可能性。體外穿透實驗結果顯示，與無微脂粒包覆之類薑黃素進行比較時，離子電透法可增加微脂粒包覆類薑黃素之皮膚累積穿透量（cumulative amount）與通量（flux）約五倍（7.52 vs. 1.60 μg/cm2）。
　　根據本研究一系列之實驗結果，我們可得到以下結論：以微脂粒作為藥物載體包覆後可增加乳癌細胞對於類薑黃素之攝入並且促進與延長類薑黃素對於乳癌細胞之毒殺效果。再經由離子電透法之協同作用，微脂粒之經皮輸送治療乳癌模式將是未來乳癌治療上很重要的開端。

關鍵字

類薑黃素 ； 乳癌 ； 微脂粒 ； 離子電透法

並列摘要

Curcuminoids is a predominant compound which derived from the rhizomes of Curcuma longa L. it has anti-neoplastic, anti-inflammatory and antibacterial activities. In recent studies, curcuminoids has been shown anti-proliferation and induce the apoptosis in some breast cancer cell lines. In this MSc thesis research, curcuminoids was chosen as the model drug and liposome, a biocompatible and biodegradable carrier, was used as a carrier for curcuminoids. The iontophoresis technique was also investigated for the possibility of facilitating the skin permeation of curcuminoids encapsulated in the liposome. Formulation development studies, the dimyristoylphosphocholine and cholesterol at the molar ratio of 1:1 was selected for liposome preparation.
To study the cytotoxicity effects of liposome encapsulated curcuminoids in breast cancer cells, three breast cancer cell lines (MCF-7, MDA-MB-435S and MDA-MB-231) were selected and the cytotoxicity was detected by MTT method. The cell viability of breast cancer cells was found to decrease as elevated the loading level of curcuminoids in the liposome. The IC50 value of the liposome-encapsulated curcuminoids was found to be lower than the non-encapsulated curcuminoids in breast cancer cells. Those results suggest that the liposome enhanced the cellular uptake of curcumin into the breast cancer cells. The liposomal encapsulation was also observed with a sustained cytotoxic effect. In addition to, the HPLC technique was developed for quantization the cellular uptake of curcumin. The cellular uptake of curcumin was extracted form the breast cancer cells and the results shown that a dose-dependent manner with the concentration of curcuminoids. The cellular uptake of curcumin in the liposomal formulation was higher than free-form curcuminoids. Those results indicated that liposomal encapsulation might enhance the uptake of curcumin in the breast cancer cells.
In-vitro permeation studies in a newborn pig skin, we found that iontophoresis has elevated the cumulative amount and flux of curcumin which encapsulated by liposome. There are five folds increasing which compared to the curcumin without liposomal encapsulation (7.52 vs. 1.60 μg/cm2 ).
Summary the results of this study, that the liposomal encapsulation could enhance and prolong the cytotoxicity of curcuminoids through possibly increase the cellular uptake of curcuminoids in breast cancer cells. Through the use of iontophoresis, the transdermal delivery of liposome encapsulation to the breast cancer cells could be made possible.

並列關鍵字

Curcuminoids ； Breast cancer ； Liposome ； Iontophoresis

參考文獻

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