Study on the Putative Structure and the Biological Functions of Fucoidan

• Main Authors: Mi-Hsuan Lin, 林宓璇
• Other Authors: Hsien-Yeh Hsu
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/59245635011318004556

碩士 === 國立陽明大學 === 醫學生物技術暨檢驗學系 === 102 === Fucoidan, a water-soluble and sulfated-fucans having complicated chemical structures, commonly found in brown seaweeds. Our previous studies demonstrated that fucoidan inhibits the growth of lung cancer cells and breast cancer cells. Here, we focus on the relationship between its chemical composition and in vitro anticancer activity. The major low molecular mass of fucoidan is named LMF and estimated average molecular mass about 500 Da by size-exclusion high-performance liquid chromatography (SEC-HPLC). To examine the content of fucose of LMF, we hydrolyzed the LMF via autoclave (121℃) and acetic acid. The residue was further applied the high-performance anion exchange chromatography (HPAEC) to identify the content of fucose from hydrolyzed LMF. We found that the released fucose from LMF was increased with a time-dependent manner by autoclave or a does-dependent of acetic acid in autoclave. Next, we examined the anti-cancer activity of the hydrolyzed LMF. Our previous studies demonstrated that fucoidan enhances transforming growth factor β (TGFβ) and its receptors (TGFRs) degradation in cancer cells. Here we found that LMF enhanced TGFRs degradation, whereas, the hydrolyzed LMF did not affect expression of TGFRs and decrease the viability of cancer cells. Furthermore, we examined the components of LMF by electrospray ionization mass spectrometry (ESI/MS), we found that the sulfated fucose group presented on the LMF. The results showed an essential factor in this study, the hydrolyzed LMF lost the sulfated group from fucose that the higher content of sulfated fucose group of LMF (SO3-LMF) induced the expression of LC3-II (an autophagy marker), but not hydrolyzed LMF. Taken together, we proposed that the bioactivity of fucoidan may be contributed from the content of sulfated fucose group on low molecular mass fucoidan.