| Summary: | 碩士 === 國立陽明大學 === 生物藥學研究所 === 87 === A neural stem cell is defined as a single cell capable of proliferating, exhibiting self-maintenance or renewal over the lifetime of the organism, generating a large number of clonally related progeny, retaining its multilineage potential over time, and producing new cells in response to injury or disease. Neural progenitor cells from striata of adult mice develop into either astrocytes or neurons when cultured in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). Using a method similar to that used by Renold and Weiss, we were able to isolate multipotential progenitor cells from the forebrain of newborn rat. In this study, we further established the culture system of the EGF-responsive neural progenitor cells from newborn rat brain and used them as a model for sample screening. We also used Hochst33342 (H33342) staining method to determine neural cell proliferation and monitored the morphological changes of these cells to verify their differentiation.
Docosahexaenonic acid (DHA) is one of the major long-chain unsaturated fatty acid (PUFA) normally existence in mammals and fishes. Highest concentration of this substance is found in brain and retina. The enhancing effect of dietary DHA on the learning ability of rats has been reported by Fujimoto et al. It is well known that activation of the N-methyl-D-aspartate (NMDA) receptor is absolutely required for the induction of long-term potentiation (LTP) in the hippocampal CA1 region and neocortex. Recently, the facilitated effect of DHA on NMDA response has been reported. Therefore, DHA may play a role in promoting the induction of LTP. In the present study, we showed that DHA could promote the differentiation of neural progenitor cells by examining their mophological changes and by the flow cytometric analysis of cells stained by a monoclonal anti-nestin antibody. These results suggest that DHA may play a role in regulating CNS development.
Oolong tea is a popular drink reported to have a variety of benefits to human health. However, the mechanisms underlying its health-improving effects are still unclear. We chose H33342 staining assay to identify compounds from oolong tea capable of promoting cell proliferation. Fractionation of crude extracts and purification of active ingredients were conducted by organic solvent partitioning, sephadex LH-20 chromatography, high speed countercurrent chromatography, and reverse phase HPLC. Two active compounds, designated respectively as TeaMPeL3C3 and TeaMPeL3C4 were isolated and the latter was further subjected to NMR spectometric analysis and its identity was found to be caffeine.Taken together, our study showed that DHA and two compounds isolated from oolong tea promoted EGF-responsive neural progenitor cells to proliferation and differentiation.
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