製備具促進視網膜健康功效之金盞花萃出物微脂體

Abstract

隨著科技日漸發達，3C 產品的長期使用，導致眼睛負擔越來越大，對眼部保健的需求越來越高。根據研究指出，攝取葉黃素可補充黃斑部中的色素含量，有助於預防眼疾例如黃斑部病變的產生，因此，適量補充葉黃素至關重要。金盞花 (Marigold flower) Tagetes erecta中含有豐富的葉黃素，為商業上葉黃素保健食品最大的來源，然而在萃取出葉黃素後，剩餘殘渣往往直接丟棄，其中仍含有高量酚類等水溶性植化素，對眼睛健康亦有助益，直接丟棄造成浪費。微脂體係由磷脂雙層組成的球型囊泡，可做為載體；相較於其他奈米化技術，其具備生物相容、可生物分解、低成本及低毒性等特性，且可同時包埋親水及疏水性成分。本實驗之目的即為以微脂體同時包埋金盞花中脂溶性葉黃素及水溶性活性物質，提升金盞花之護眼價值，同時克服葉黃素穩定性不佳且生物利用率低的限制。 研究結果顯示，當微脂體配方組成為卵磷脂及膽固醇莫耳比例 1：1、葉黃素及卵磷脂莫耳比例 1：10、水溶液中總酚類濃度為 400 µg GAE/mL時，可建構出結構穩定的金盞花萃出物微脂體，且葉黃素的包埋率可達 82%，多酚類物質之包埋率則為 31.7%；微脂體之粒徑大小約 1030.8 nm，界達電位為 -38.28 mV。此外，金盞花萃取物經微脂體包埋後成功提升了葉黃素的儲存穩定性；金盞花萃取物微脂體經 1 小時模擬胃液作用後，葉黃素釋出率僅 3.7 %，顯示微脂體可保護葉黃素經過胃酸的侵蝕。而在人類結腸癌細胞 Caco-2 體外吸收平台中，結果表明經包埋後萃取物之葉黃素相較於未包埋者吸收率提升了 43.7%，顯示以微脂體包埋是提升吸收率的有效加工方式。最後，於人類視網膜色素上皮細胞 ARPE-19 細胞平台中，金盞花萃取物微脂體可以提升 ARPE-19 細胞於 H2O2 誘導氧化傷害下的存活率，證明其對視網膜細胞具有保護的功能。綜合上述，本研究成功建構出具促進視網膜健康功效之金盞花萃出物微脂體，提升了金盞花之價值，並解決了葉黃素低穩定性及低吸收率的限制。

With new technological advances, the long-term use of 3C products has led to an increasing burden on the eyes. According to the previous researches, lutein can specifically accumulate in the macular and reduce the risk of macular degeneration. As a result, sufficient lutein supplementation is of critical importance. Marigold flower (Tagetes erecta) contains high amount of lutein, which is the largest source of commercial lutein supplement. However, after lutein extraction, the remaining residue is often discarded, which still contains high amounts of water-soluble phytochemicals, such as phenols, they are also effective compounds for eye health and could be wasted if abandoned. Liposome is a sphere vesicle composed of phospholipid bilayer. Compared to other nanotechnology, liposome possess several advantages including biocompatible, biodegradable, low cost, low toxicity, and able to co-encapsulate both hydrophilic and hydrophobic compounds. The purpose of this study was to co-encapsulate both hydrophilic and hydrophobic compounds extracted from marigold flower in liposomes, expand the value of marigold flower, and overcome the low stability and bioavailability of lutein. Results of this study indicated that stable marigold extract liposomes could be constructed at the molar ratio of lecithin to cholesterol 1 : 1, the molar ratio of lutein to lecithin 1 : 10, and the concentration of total phenol content in the hydration solution was 400 μg GAE/mL. The encapsulation efficiency of lutein could reach 82%, while phenolic compound was 31.7%. The particle size of the marigold extract liposome was approximately 1030.8 nm, and the zeta potential was -38.28 mV. The storage stability of lutein encapsulated in liposome was improved as compared with free lutein. In addition, the marigold extract liposome only released 3.7% lutein in simulated gastric fluid for 1 h, indicating that liposomes could protect lutein from gastric acid. Furthermore, In vitro Caco-2 intestinal permeability assay showed that the encapsulation increased 43.7% absorption rate of lutein, revealing that liposome encapsulation is a feasible way to improve lutein absorption. The protective effect of retinal epithelial cells by marigold extract liposome was also demonstrated using the ARPE-19 cell model. The viability of the cells under H2O2 induce oxidative damage was significantly increased. In conclusion, the functional marigold extract liposome was successfully constructed in this experiment, which not only increased the eye protection value of marigold flower, but also ameliorated the storage stability and absorption of lutein.