- 學位論文
台灣栽培山藥之免疫促進作用活性研究
The Immunostimulatory Effects of Dioscorea Tuber Cultivated in Taiwan
摘要
山藥為薯蕷科(Dioscoreaceae)薯蕷屬(Dioscorea)多年生蔓生性根莖類植物，可供食用，有滋養、強壯、止瀉及降血糖等功效，自古以來，山藥塊莖即為著名養生滋養食品，而本研究則針對免疫調節機能方面，進行台灣栽培優質山藥TA-05(Dioscorea alata L.)根莖(擔根體)之熱水抽取物及多醣體之免疫調節活性研究。 TA-05山藥根莖之熱水抽取物經去蛋白質、澱粉經3500D濾膜透析後，可得約3%乾重的山藥粗多醣體，體外試驗使用BrdU分析小鼠脾臟淋巴細胞增生活性，並分析細胞激素分泌與對小鼠巨噬細胞株RAW 264.7吞噬能力檢測，結果發現TA-05山藥多醣體可促進小鼠脾臟淋巴細胞增生、細胞激素IL-2、IFN-γ分泌量增加、增強巨噬細胞株RAW 264.7之吞噬能力。 體內試驗中，BALB/cByJ小鼠管餵TA-05山藥根莖熱水抽取物、多醣體，投與後第15天（二週）、29天（四週）犧牲小鼠，測量脾臟、胸腺重量與體重的比值、以流式細胞儀分析脾臟T和B淋巴細胞的增生能力，並分析血清免疫球蛋白濃度、細胞激素IL-2、IL-4、IFN-γ濃度，以評估TA-05山藥對健康小鼠免疫反應之調節作用。 體內結果顯示投與TA-05山藥根莖熱水抽取物、多醣體四週後，小鼠脾臟重量與體重比值明顯增加，流式細胞儀之分析顯示小鼠脾臟B淋巴細胞數量有提高現象，小鼠血清免疫球蛋白IgG1、IgG2a、IgG2b、IgG3、IgM之濃度均明顯提高，免疫球蛋白活化之對應細胞激素IL-4之分泌亦明顯增加。實驗結果證實台灣栽培優良山藥TA-05之根莖熱水抽取物、多醣體藉由促進細胞激素IL-4之分泌，調控刺激免疫球蛋白IgG、IgM之分泌，達到增強體液性免疫的效果，且多醣體之作用優於熱水抽取物。
並列摘要
Dioscorea tuber is a tuberous herb which belongs to the Dioscoreaceae family that grows in West Africa, East Asia, in regions of China, Japan, Taiwan. It is a traditional Chinese medicine that is commonly used to nourish, strength, antioxidant, immunostimulatory activities. The aim of the present study was to evaluate the in vivo and in vitro immunostimulatory effects of TA-05, a cultivated yam in Taiwan, and the murine innate and adaptive immunities were investigated. The hot water extracts (HWE) and polysaccharides (PLS) of tubers of Dioscorea alata L.(TA-05) were evaluated in vitro for its ability to induce lymphocytes proliferation by BrdU assay, cytokines secretion and the stimulation index on the phagocytosis of the murine macrophage RAW264.7 cell line. Results indicated that HWE and PLS of TA-05, respectively enhanced the splenocytes proliferation, IL-2 and IFN-γ production in cultured lymophocytes of BALB/cByJ mice. The phagocytic activity of RAW 264.7 cell line was enhanced by treatment with HWE and PLS of TA-05, respectively for 24 hours . In the in vivo study, BALB/cByJ mice were administered with the HWE and PLS of TA-05, respectively for 14 and 28 days. After treatment, the ratio of spleen and thymus weight to body weight were measured and then investigated for lymphocytes proliferation activity by flow cytometry; levels of immunoglobulins and cytokines of IL-2, IL-4, IFN-γ in serum were also evaluated. HWE and PLS from TA-05 were observed significantly to increase the ratio of spleen weight to body weight at 14 and 28 days. Flow cytometry results indicated that murine B lymophocytes numbers were also increased. Serum cytokine IL-4 and immunoglobulins IgG1, IgG2a, IgG2b, IgG3, and IgM were significantly augmented after treated with HWE and PLS from TA-05. These results suggested that TA-05 enhanced IgG secretion possibly via IL-4 regulation. Moreover, the PLS from TA-05 were also observed to exhibit superior effects over its HWE. These results suggested that TA-05 tuber polysaccharide have immunostimulatory activity via enhanced the levels of immunoglobulins (in vivo), lymphocytes proliferation, cytokine secretion, macrophage phagocytosis (in vitro).