- 學位論文
靈芝天然物GG1與GG3的降血糖活性分析
Study on the hypoglycaemic activities of two natural products isolated from Ganoderma lucidum
摘要
本實驗室於前期研究中，發現中國南瓜 (Cucurbita moschata)含有降血糖天然物，其中天然物 (22E,24R)-24-methyl-6-methoxy-5-cholesta- 7,22-diene-3-diol (MMCD)具有胰島素類似物、胰島素增敏劑和胰島素替代劑等3種功能。而靈芝所含的天然物中，有兩個天然物與MMCD的結構非常相近，分別是GG1與GG3。因此，本研究欲探討GG1與GG3是否與MMCD一般，有多重的降血糖功能。結果，GG1與GG3皆可以促進正常細胞與胰島素抗性細胞吸收葡萄糖，顯示具有降血糖的活性。促進正常細胞吸收葡萄糖的效果可能與活化AMP-activated protein kinase有關。對胰島素抗性的細胞則是有胰島素增敏劑的效果，卻無胰島素替代劑的功能，故與MMCD的活性不盡相同。GG1與GG3的分子機制仍未完全明瞭，尚待進一步分析
並列摘要
In a previous study of this laboratory, the crude extract of Cucurbita moschata stem was found to contain hypoglycaemic natural products. A natural compound, (22E,24R) - 24-methyl- 6-methoxy- 5- cholesta- 7, 22- diene-3- diol (MMCD) was isolated from the crude extract, and confirmed to have triple functions, i.e., insulin-like activity, insulin sensitizing, and insulin substitution. GG1 and GG3 are two natural compounds isolated from Ganoderma lucidum. Their structures are very similar to that of MMCD. Hence, the purpose of this study is to explore whether GG1 and GG3 have multiple hypoglycaemic functions as MMCD does. Consequently, GG1and GG3 promoted the glucose consumption of Clone 9 cells, a rat normal hepatic cell line, suggesting that GG1 and GG3 have insulin-like activities, and this effect may be associated with the activation of AMP-activated protein kinase. Moreover, GG1 and GG3 showed insulin sensitizing activity in insulin-resistant cells, but did not exhibit insulin substitution functions. Thus, the functions of GG1 and GG3 are not identification with that of MMCD. The molecular mechanism underlying the functions of GG1 and GG3 are not clear and need to be further explored.