The molecular property and immunostimulatory activity of Chlorella sorokiniana glycoproteins and their modified products with certain organic acids

• Main Authors: Jiang, Kun-yu, 江坤諭
• Other Authors: Lai,Phoency
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/30377148996198234469

碩士 === 靜宜大學 === 食品營養學系 === 99 === This study was to investigate the molecular property and in vitro immunostimulatory effect of hot water extract (WS) and destarched WS (WS-ds) of Chlorella sorokiniana, and their molecular fractions as well as modified WS-F1 with a certain of organic acids (serine, cysteine, glutamic acid, ascorbic acid, and citric acid). The molecular fractions prepared by tangential flow filtration included WS-F1 (> 100 kDa), WS-F2 (10-100 kDa), WS-F3 (< 10 kDa), WS-ds-F1, WS-ds-F2, and WS-ds-F3. The monosaccharide compositions of all samples prepared were mainly glucose. The in vitro immunostimulatory effect using murine Raw264.7 cell model indicated that WS-F1 exhibited the highest proliferation effects (269% at 5 μg/mL) among the samples examined. By Fourier transform infrared spectroscopy (FTIR), the WS-F1 modified with certain organic acids via a process of mixing, alkalization, and neutralization, displayed characteristic absorption peaks at 1050-1300 cm-1(C-O), 1690-1760 cm-1(C=C) and 3000-3500 cm-1(O-H). Among the modified products, only WS-F1 modified with serine (WS-F1-S) and citric acid (WS-F1-C) promoted Raw 264.7 cell proliferation significantly (140% and 133%, respectively, at 100 μg/mL). The WS-F1、WS-F1-S、WS-F1-C stimulated significantly Raw 264.7 cells to secrete tumor necrosis factor-α (TNF-α) (505.1±11.2, 524.9±6.4, and 491.6±9.2 pg/ mL at 100 μg/mL). The WS-F1 and WS-F1-S stimulated Raw 264.7 cells to secrete significant amounts of interleukin-6 (IL-6) (450.6±10.7 and 211.5 ± 11.0 pg/mL at 100 μg/mL). In conclusion, C. sorokiniana fractions especially of a molecular weight >100 kDa exhibited excellent abilities in activating macrophage to proliferation and secreting cytokines TNF-α and IL-6, which were dose-dependent. Modification of serine and citric acid conditioned the in vitro immunostimulatory activity of WS-F1 on Raw 264.7 cells. Keywords: Chlorella sorokiniana, glycoprotein, esterification, macrophage, immunomodulation