蓮子心延緩線蟲老化之有效成分探討

Abstract

老化是一種隨著年齡的增加而造成細胞、組織中有害變化之累積進而增加疾病及死亡等危害的進程。造成老化的原因有很多，其中包含了發育及遺傳缺陷 (developmental and genetic defects)、環境因素 (the environment)、疾病的進程 (disease processes) 以及固有的老化現象 (inherent process) 等。根據聯合國近年來的統計，無論在何種開發程度的國家，其人口組成已逐漸高齡化，老化指數 (aging index) 逐漸攀升，預估 2050 年時大於 60 歲的人口將佔總人口數的 21%，伴隨老化而來的問題將日益漸增，因此抗老化在現今的社會中便成為一重要課題。 抗老化的方式有很多，飲食為其中一種方式。過去本實驗室探討過許多花果以及中草藥萃出物在抗老化方面的效果，蓮子心 (Nelumbo nucifera Gaertn. seed embryo) 為其中一項。秀麗隱桿線蟲 (Caenorhabditis elegans) 具有生命週期較短、基因定序完全、易於實驗室環境下培養等優勢，故本實驗室選用線蟲作為研究老化的動物模式探討蓮子心中有效抗老化之成份。根據過去本實驗室研究結果發現蓮子心甲醇粗萃物正丁醇區分層之第五區分物 (Nn-M-B-V) 具有延長線蟲平均壽命的能力，與控制組 (0.05% DMSO) 相比能延長 8.2% 的平均壽命。因此本研究接續過去實驗結果，進一步以高效液相層析儀分離純化第五區分物並得到四個次區分物 (Nn-M-B-V-1、Nn-M-B-V-2、Nn-M-B-V-3、Nn-M-B-V-4)，根據高效液相層析儀初步分析得知 Nn-M-B-V-3 以及 Nn-M-B-V-4 含有主要波峰，因此進一步以線蟲之壽命實驗探討此二區分物對線蟲壽命之影響，發現其中 Nn-M-B-V-3 具有顯著延長線蟲壽命之能力，在 4 次線蟲壽命實驗結果中，Nn-M-B-V-3 (0.25 ppm/10 mL NGM agar) 所能延長壽命之最大程度為 11.86%，最小為 3.54%。 本研究針對線蟲壽命實驗最有效之 Nn-M-B-V-3 進一步純化分離，根據 LC/MSn 結果可得知 Nn-M-B-V-3 由 3 個不同的主要化合物所組成 (peak-1、 peak-2 及 peak-3)，且分子量皆為 564。進一步將 3 個化合物以高效液相層析儀分離並收集，以核磁共振分析 peak-2，初步判定此化合物為含有兩個醣基的類黃酮類物質。

Aging is accumulation of diverse deleterious changes in the cells and tissues advancing with age that increase the risk of disease and death. Aging changes can be attributed to development and genetic defects, the environment, disease process, and an inherent process, referred to as the aging process. According to the world population composition, the proportion of older people and the aging index continue to rise. It is assumed that the proportion of elderly people (>60 years old) will rise to 21% of the world population. The associated problem will also rise. Therefore, anti-aging will be an important issue in the society. There are a lot of factors possess the anti-aging activity. One of these factors is food intake. Our group has evaluated the anti-aging activity of many extracts from the flower, fruit and herbal. One of these is Nelumbo nucifera Gaertn. seed embryo. Caenorhabditis elegans is an animal model which has short life cycle and its genome is well defined. Besides, it is easily to raise under the lab environment. Therefore, the C. elegans is chosen as the model to screen out the anti-aging compound(s) in the N. nucifera Gaertn. seed embryo. We have found that the fifth fraction of n-butanol fraction of methanol extract of N. nucifera Gaertn. seed embryo (Nn-M-B-V) can ignificantly extend the mean lifespan of C. elegans by 8.5%. Therefore, HPLC was employed to separate Nn-M-B-V and two sub-fractions (Nn-M-B-V-3 and Nn-M-B-V-4) were collected. According to the result of lifespan test, we found that the Nn-M-B-V-3 can significantly extend the mean lifespan by maximum 11.86% and minimum 3.54%. In the past research, we assumed that the Nn-M-B-V-3 is flavonoid. We try to separate and purify the Nn-M-B-V-3. The LC/MSn result suggested that Nn-M-B-V-3 contain 3 major compounds, which has the same molecule weight—564. That, these 3 major compounds were separated by HPLC and collected for NMR analysis. According to the NMR result, we preliminary assume that peak-2 is a diglycoside flavonoid.