Immunological and antitumor activity assays for the marine red alga Gracilaria tenuistipitata.
Date Issued
2006
Date
2006
Author(s)
Jen, Ya-Ching
DOI
zh-TW
Abstract
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.
Subjects
細基龍鬚菜
海藻
Gracilaria tenuistipitata
alga
SDGs
Type
thesis
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