| 摘要: | 印度辣木 (Moringa oleifera) 源自於西馬拉雅山，是豆科 (Leguminosea) 植物，為灌木的一種，俗名為油辣木、奇蹟之樹、山葵木，營養成份極高，擁有豐富的維生素、礦物質，當地人甚至會取樹葉的部份直接生食，在當地民俗治療上印度辣木具有降低高血壓、提升免疫力不足、治療糖尿病、骨骼疾病、其它各種腫瘤疾病與發炎疾病等等功效。早期有人利用辣木油製成香水，種子可以製成淨水劑，樹根做為調味料，幾乎整株都可以利用，在當地是株非常具有經濟價值的一種植物。據統計目前全世界約有 14種辣木，目前台灣引進栽種約有3種食用品種，即印度傳統辣木 (M..oleifera)、印度改良種辣木 (M..oleifera PKMI) 和非洲辣木 (M.. stenopetala)。
本研究取印度傳統辣木 (M. oleifera) 新鮮木材部10公斤，經95%乙醇萃取後，再依極性不同採液液層相分離，取正己烷層進行高壓液相層析，目前分離出有兩種主要植物固醇類β-sitosterol和stigmasta-5,22-dien-3β-ol的成份。生物活性實驗上使用溶解的溶劑通常是DMSO、乙醇和水，樣品溶解度極低，造成藥物在實驗過程往往沈澱析出，使得在接觸細胞的機會大減，本研究使用毒性低的TTD8界面活性劑，將植物固醇類化合物分散在水相細胞培養液中，利用這均勻分散的效果，以老鼠巨噬細胞為實驗模式，進行抗發炎活性之分子機制研究，這是首創嘗試利用混合配方溶劑，提高固醇類化合物在水中之溶解度與均勻性。利用在天然物中大量存在的固醇類化合物，尤其是用於植物固醇的開發之研究並不多，同時對於植物固醇化合物在分子細胞之作用仍是一團迷，因此我們預估透過此實驗模式，將有助於解析固醇類化合物在細胞內訊息傳遞的途徑，期望未來成為開發新藥重要依據。
Moringa oleifera, a shrub or small tree originates in western Himalayan Mountain, and belongs to the Leguminosea family. The tree is referred to as drumstick tree, tree of miracle, Indian moringa etc. and has exceptionally high nutritional values from a vegetative source, with rich vitamins, and minerals. In addition of eating seed pods and leaves in dishes, the leaves are even ingested raw directly as a greenery. Ethnobotanically, the tree is known to reduce blood pressure, enhance deficient immunity, cure diabetes, bone diseases, and various tumors, inflammations etc. In earlier days, the oil from the species was prepared as a perfume. The seeds can be prepared as a good water purifier, and roots of the tree used as a condiment. Almost the entire tree is useful, and high economic value is provided by the species. There are a total of 14 species in the family. In Taiwan, 3 species are cultivated as vegetables which are M. oleifera, M. oleifera PKMI, and M. stenopetala.
Fresh wood of M.oleifera weighted 10 kg was extracted with 95% ethanol. The extract was fractionated and the Hexane layer was subjected to an HPLC analysis. Two main sterols, β-sitosterol, and stigmasterol were isolated. Since these compounds have very poor solubility in commonly used experimental solvents, water and ethanol, they often precipitate out before coming in contact with the targeted cells and making the study of their pharmaceutical property very difficult. Thus, in this study, the purpose of our study was to develop a means of delivering the substances to a cellular assay system. We used a low toxicity solvent formulation to encapisulate the sterol compounds in an aqueous cell culture medium and achieved homogenous dispersion of the compounds. Subsequently using a murine macrophage cell and a human skin fibroblast cell models, we investigated the molecular mechanisms of anti-inflammatory activities of the compounds. This is the first known case of attempting to use a mixed solvent formulation to increase the solubility and homogeneity of sterol compounds in water which allow the effective medicinal development and applications of sterols that exists in large quantities in certain natural products.
Up to now, our understandings of the roles sterol compounds play at cellular molecular mechanism level are quite sketchy. We expect that through the experimental model we’ve demonstrated here, the roles of sterols in the pathways of cellular signal transmission can be delineated in the future. And it will become an important benchmark in new drug developments. |
