碩士 / 國立臺灣大學 / 海洋研究所 / 94 / The marine red alga Gracilaria tenuistipitata (Gracilariaceae) was assayed in vitro for proliferation stimulation in murine macrophage and antitumor activity against MDAMB-231, MIA Paca-2 and Hep G2. The bioactive substances were extracted in phosphate buffer saline and hot water, followed by purification and biochemical characterization. It appeared that both saline and hot-water extracts could significantly stimulate macrophage proliferation and, on the contrary, inhibit tumor cell growth. However, the isopropanol -precipitated polysaccharide had greater stimulation activity than hot-water extract, with maximal activity, i.e. proliferation increased by 48.7%, at concentration of 15.6 μg/ml. The extract at 60℃ for 3 hr inhibited markedly the growth of tumor cells used, i.e. cells survivability decreased by 46~59% as compared with the control. A novel protein assigned as GTP was obtained from the reported alga after being extracted in saline, then precipitated by saturated ammonium sulfate, and finally isolated by ion-exchange and gel filtration column chromatography. The isolated protein was a dimmer in structure, having two subunits of 20 and 35 kDa as explained on SDS-PAGE and gel filtration and absorbance at 498,546 and 565 nm. As shown in the results, macrophage proliferation increased by 79~83% and, on the contrary, tumor cell survivability reduced by 74.1~80.9% in the presence of GTP at concentration as low as 0.05~0.1 μg/ml. However, it did not agglutinate human A, B, O and AB erythrocytes. Additionally, GTP was not tolerable to high temperature, as well as acidic and alkaline solutions; when the stimulation activity reduced greatly while subjected to 80 ℃ and or pH<6.0 or >8.0. The above findings suggested that Gracilaria tenuistipitata is a promising source of bioactive polysaccharides and proteins in use for health care and medicine.
| Identifer | oai:union.ndltd.org:TW/094NTU05274022 |
| Date | January 2006 |
| Creators | Ya-Ching Jen, 任雅罄 |
| Contributors | 黃穰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 58 |
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