農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

在生物體中，骨骼的維持是一個循環性的修建工程，包含骨質生成 (bone formation) 及骨流失(bone resorption)。鋸齒麒麟菜 (Eucheuma serra) 為臺灣大宗食用藻類原料，富含鈣質與植化素，因此本研究旨在探討其酵素水解物作為骨質保健素材的可行性與作用機轉。首先分析麒麟菜組成，發現其豐富的鈣質 (1.29 ± 0.06 g/100 g) 可滿足國人1日鈣的攝取量，同時也含有23.11 ± 0.08 g硫酸多醣可協同促進骨生成作用。MG-63造骨細胞實驗發現，0.625 mg/ml麒麟菜酵素水解物，可顯著提升細胞中第一型膠原蛋白與鹼性磷酸酶分別達154.36% (p < 0.05) 與164.43% (p < 0.05)，顯示具有促進骨母細胞成熟分化為硬骨細胞及生成骨基質的能力。噬骨細胞試驗証實，250–500 µg/ml麒麟菜酵素水解物不僅可調降噬骨細胞成熟與分化相關基因如核因子κB受體 (receptor activator of nuclear factor kappa-B)、T細胞活化核因子 (nuclear factor of activated T-cells) 和樹突細胞特異性跨膜蛋白 (Dendrocyte expressed seven transmembrane protein) 等mRNA 表現量為控制組之0.11–0.06；0.24–0.10和0.75–0.50倍，同時細胞核的染色結果顯示抑制形成成熟多核的噬骨細胞，並對細胞酒石酸酸性磷酸酶 (tartrate-resistant acid phosphatase) 活性呈現劑量性的抑制作用，其中500 µg/ml麒麟菜酵素水解物調降B細胞淋巴瘤2 (B-cell lymphoma 2) 抗凋亡基因 mRNA 表現量為對照組0.45倍，並提高BCL-2相關x蛋白 (BCL-2-associated x protein) 促凋亡基因 mRNA 表現量達對照組2.91倍，此等結果顯示麒麟菜酵素水解物會抑制噬骨母細胞的分化成熟與骨基質中鈣磷礦化物的分解，另對成熟噬骨細胞也會啟動細胞凋亡阻斷噬骨作用，進而緩解骨質流失。在摘除卵巢誘導骨鬆大鼠動物模式則確效，以500 mg/kg/day連續投餵6 週後，可提升試驗鼠血清中骨源鹼性磷酸酶 (bone-specific alkaline phosphatase) 含量 (0.19 ± 0.03 ng/ml) 與降低第一型膠原蛋白之氮末端肽鏈含量 (4.69 ± 1.80 μmol/ml)，表示具有促進骨質生成和抑制骨質流失的作用；同時提升骨質密度 (bone mineral density) 值，並如同市售骨鬆治療藥物 (福善美保骨錠)，皆具有提高骨鬆鼠股骨之骨小樑厚度與面積以及減少骨小樑間隙。另麒麟菜酵素水解物經由基因毒性試驗則証實本身及其代謝產物皆不具致突變性；口服急毒性則驗證其半數致死劑量 (median lethal dose, LD₅₀) 大於 1 g/kg BW，基此，以骨鬆動物模式驗證麒麟菜酵素水解物有效濃度500 mg/kg/day劑量換算成人每日建議攝取量為4.8 g。

The maintenance of bones is referred to as the "bone remodeling cycle," which has two components: osteogenesis and bone loss. On the other hand, E. serra is an abundant source of calcium and phytochemicals in Taiwan that is used as an edible algal raw material. This study aims to investigate the mechanism and enzymatic hydrolysis of E. serra for the development of bone healthcare products. We discovered that 100 grams of E. serra contains 1.3 ± 0.06 g of calcium, which is sufficient to meet the daily calcium needs of humans, and that 23.11 ± 0.08 g of sulfated polysaccharide can promote osteogenesis in a synergistic manner. When 0.625 mg/ml E. serra hydrolyzate was added to the maturation of osteoblasts (MG-63), the type I procollagen and alkaline phosphatase levels increased by 154.36% (p < 0.05) and 164.43% (p < 0.05), respectively. Which demonstrated that E. serra hydrolyzate can promote osteoblast maturation and mineralization. In addition, it was confirmed that 250-500 µg/ml E. serra hydrolyzate down-regulated the mRNA expression of genes related to osteophyte maturation and differentiation, including RANK, NFATc1, and DC-STAMP, which were 0.11-0.06; 0.24-0.10; and 0.75-0.50 in the control group. In addition, nuclear staining revealed that it inhibited the formation of mature multinucleated osteophytes and exhibited a dose-dependent inhibition of cell TRAP activity. BCL-2 and BAX mRNA expression were 0.45-fold and 2.91-fold of the control group, respectively. This variant demonstrated that E. serra hydrolyzate mitigates bone loss by promoting osteoblast apoptosis and inhibiting the decomposition of calcium minerals in the bone matrix. In ovarian removal animal experiments, after 6 weeks of continuous administration of 500 mg/kg/day E. serra hydrolyzate, the B-ALP content (0.19 ± 0.03 ng/ml) increased and the NTx content (4.69 ± 1.80 μmol/ml) decreased in the serum of test rats, indicating that E. serra hydrolyzate promoted bone formation and prevented bone loss. Also, the femoral bone mineral density, trabecular bone thickness, and trabecular bone area ratio of rats were found to be slightly or significantly greater than those of the control solution group, just as Fosamax PLUS did. In addition, genotoxicity testing revealed that E. serra hydrolyzate and its metabolites were not mutagenic, and the median lethal dose (LD50) for acute oral toxicity was greater than 1 g/kg BW. Based on all available data, the recommended daily adult dose of E. serra hydrolyzate is 4.8 g.